AMERICA WEST AIRLINES INC
S-4, 1999-02-02
AIR TRANSPORTATION, SCHEDULED
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<PAGE>   1
 
    AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON FEBRUARY 2, 1999
 
                                                      REGISTRATION NO. 333-
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
 
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                            ------------------------
                                    FORM S-4
                             REGISTRATION STATEMENT
                                     UNDER
                           THE SECURITIES ACT OF 1933
                            ------------------------
                         COMMISSION FILE NUMBER 1-10140
 
                          AMERICA WEST AIRLINES, INC.
             (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)
 
<TABLE>
<S>                                                    <C>
                    DELAWARE                                              86-0418245
(STATE OR OTHER JURISDICTION OF INCORPORATION OR             (I.R.S. EMPLOYER IDENTIFICATION NO.)
                  ORGANIZATION)                                         (602) 693-0800
          4000 E. SKY HARBOR BOULEVARD                  (REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA
          PHOENIX, ARIZONA 85034-3899                                       CODE)
    (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)
</TABLE>
 
                            ------------------------
                                      4512
 
            (PRIMARY STANDARD INDUSTRIAL CLASSIFICATION CODE NUMBER)
                            ------------------------
                               STEPHEN L. JOHNSON
 
                   SENIOR VICE PRESIDENT -- CORPORATE AFFAIRS
                          AMERICA WEST AIRLINES, INC.
                          4000 E. SKY HARBOR BOULEVARD
                          PHOENIX, ARIZONA 85034-3899
                                 (602) 693-0800
           (NAME, ADDRESS, INCLUDING ZIP CODE, AND TELEPHONE NUMBER,
                   INCLUDING AREA CODE, OF AGENT FOR SERVICE)
                            ------------------------
                          COPIES OF CORRESPONDENCE TO:
                              SAMUEL M. LIVERMORE
                              COOLEY GODWARD, LLP
                               ONE MARITIME PLAZA
                            SAN FRANCISCO, CA 94111
                            ------------------------
   APPROXIMATE DATE OF COMMENCEMENT OF PROPOSED SALE OF THE SECURITIES TO THE
                                    PUBLIC:
 
AS SOON AS PRACTICABLE AFTER THE EFFECTIVE DATE OF THIS REGISTRATION STATEMENT.
                            ------------------------
                        CALCULATION OF REGISTRATION FEE
 
<TABLE>
<CAPTION>
- -----------------------------------------------------------------------------------------------------------------------------
- -----------------------------------------------------------------------------------------------------------------------------
                                                             PROPOSED MAXIMUM        PROPOSED MAXIMUM
      TITLE OF EACH CLASS OF            AMOUNT TO BE        OFFERING PRICE PER      AGGREGATE OFFERING         AMOUNT OF
    SECURITIES TO BE REGISTERED         REGISTERED(1)         CERTIFICATE(2)             PRICE(2)          REGISTRATION FEE
- -----------------------------------------------------------------------------------------------------------------------------
<S>                                  <C>                  <C>                     <C>                     <C>
Pass Through Certificates,
  Series 1998-1A...................     $131,670,000               100%                $131,670,000             $36,605
Pass Through Certificates,
  Series 1998-1B...................      $41,154,000               100%                $41,154,000              $11,441
Pass Through Certificates,
  Series 1998-1C...................      $17,705,000               100%                $17,705,000              $4,922
- -----------------------------------------------------------------------------------------------------------------------------
- -----------------------------------------------------------------------------------------------------------------------------
</TABLE>
 
(1) Equals the aggregate principal amount of the securities being registered.
 
(2) Pursuant to Rule 457(f)(2), the registration fee has been calculated using
    the book value of the securities being registered.
                            ------------------------
    THE REGISTRANT HEREBY AMENDS THIS REGISTRATION STATEMENT ON SUCH DATE OR
DATES AS MAY BE NECESSARY TO DELAY ITS EFFECTIVE DATE UNTIL THE REGISTRANT SHALL
FILE A FURTHER AMENDMENT WHICH SPECIFICALLY STATES THAT THIS REGISTRATION
STATEMENT SHALL THEREAFTER BECOME EFFECTIVE IN ACCORDANCE WITH SECTION 8(a) OF
THE SECURITIES ACT OF 1933, AS AMENDED, OR UNTIL THIS REGISTRATION STATEMENT
SHALL BECOME EFFECTIVE ON SUCH DATE AS THE COMMISSION, ACTING PURSUANT TO
SECTION 8(a), MAY DETERMINE.
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
<PAGE>   2
 
THE INFORMATION IN THIS PROSPECTUS IS NOT COMPLETE AND MAY BE CHANGED. WE MAY
NOT SELL THESE SECURITIES UNTIL THE REGISTRATION STATEMENT FILED WITH THE
SECURITIES AND EXCHANGE COMMISSION IS EFFECTIVE. THIS PROSPECTUS IS NOT AN OFFER
TO SELL THESE SECURITIES AND IT IS NOT SOLICITING AN OFFER TO BUY THESE
SECURITIES IN ANY STATE WHERE THE OFFER OR SALE IS NOT PERMITTED.
 
 CONSIDER CAREFULLY THE RISK FACTORS BEGINNING ON PAGE 18 IN THIS PROSPECTUS.
 The Certificates will represent interests in trusts only and will not
 represent interests in or obligations of America West or any America West
 affiliate.
 America West is relying on the position of the SEC staff in certain
 interpretive letters to third parties to remove the transfer restrictions on
 the New Certificates.
 
                  SUBJECT TO COMPLETION DATED FEBRUARY 2, 1999
 
PROSPECTUS
 
AMERICA WEST AIRLINES, INC.
 
EXCHANGE OFFER
PASS THROUGH CERTIFICATES, SERIES 1998-1
 
                          THE EXCHANGE OFFER --
 
                          The New Certificates are being registered with the
                          Securities and Exchange Commission (the "SEC") and are
                          being offered in exchange for the Old Certificates
                          that were previously issued pursuant to an offering
                          exempt from the SEC's registration requirements. The
                          terms and conditions of the Exchange Offer are
                          summarized below and more fully described in this
                          Prospectus.
 
                                   EXPIRATION DATE          5:00 p.m. (New York
                                                            City time)
                                                             ______________ ,
                                                            1999
 
                                   WITHDRAWAL RIGHTS         Expire before 5:00
                                                             p.m. (New York City
                                                             time) on Expiration
                                                             Date
 
                                   INTEGRAL MULTIPLES         Old Certificates
                                                              may only be
                                                              tendered in
                                                              integral multiples
                                                              of $1,000
 
                                   EXPENSES                  Paid for by America
                                                             West
 
                          NEW CERTIFICATES --
 
                          The New Certificates will represent the same
                          fractional undivided interest in the trusts as the Old
                          Certificates they are replacing. The New Certificates
                          will have the same material financial terms as the Old
                          Certificates, which are summarized below and described
                          more fully in this Prospectus. The New Certificates
                          will not contain terms with respect to transfer
                          restrictions or interest rate increases and will only
                          be available in book-entry form.
 
<TABLE>
<CAPTION>
                              CLASS A CERTIFICATES          CLASS B CERTIFICATES       CLASS C CERTIFICATES
<S>                           <C>                           <C>                        <C>
PRINCIPAL AMOUNT              $131,670,000                  $41,154,000                $17,705,000
 
INTEREST RATE                 6.87%                         7.12%                      7.84%
FIRST DISTRIBUTION DATE       January 2, 1999               January 2, 1999            January 2, 1999
REGULAR DISTRIBUTION DATES    January 2 & July 2            January 2 & July 2         January 2 & July 2
FINAL DISTRIBUTION DATE
    - Expected                January 2, 2017               January 2, 2017            July 2, 2010
    - Legal                   July 2, 2018                  July 2, 2018               January 2, 2012
</TABLE>
 
NEITHER THE SEC NOR ANY STATE SECURITIES COMMISSION HAS APPROVED THESE
CERTIFICATES OR DETERMINED THAT THIS PROSPECTUS IS ACCURATE OR COMPLETE. ANY
REPRESENTATION TO THE CONTRARY IS A CRIMINAL OFFENSE.
<PAGE>   3
 
        IMPORTANT NOTICE ABOUT INFORMATION PRESENTED IN THIS PROSPECTUS
 
     You should rely only on the information provided in this Prospectus
including the information incorporated by reference. We have not authorized
anyone to provide you with different information. We are not offering the
Certificates in any state where the offer is not permitted. We do not claim the
accuracy of the information in this Prospectus as of any date other than the
date stated on the cover.
 
     We include cross-references in this Prospectus to captions within where you
can find further related discussions. The following Table of Contents provides
the pages on which these captions are located. You can find a listing of the
pages where capitalized terms used in this Prospectus are defined under the
caption "Index of Terms" in Appendix I of this Prospectus.
 
                             AVAILABLE INFORMATION
 
     America West is filing with the SEC a Registration Statement on Form S-4
relating to the New Certificates. This Prospectus is a part of the Registration
Statement, but the Registration Statement includes additional information and
also attaches exhibits that are referenced in this Prospectus. You can review a
copy of the Registration Statement through the SEC's "EDGAR" System (Electronic
Data Gathering, Analysis and Retrieval) that is available on the SEC's web site
(http://www.sec.gov).
 
     America West is required to file publicly certain information under the
Securities Exchange Act of 1934, as amended (the "Exchange Act"). All of America
West's public filings are also available on EDGAR, including reports, proxy
statements and other information. You may also read and copy all of the
Company's public filings at the SEC's public reference room in Washington, D.C.
or in their facilities in New York and Chicago. Please call the SEC at (800)
SEC-0330 for further information on the operation of the public reference rooms.
All such information is also available at the offices of the New York Stock
Exchange.
 
                INCORPORATION OF CERTAIN DOCUMENTS BY REFERENCE
 
     The SEC allows us to "incorporate by reference" information we file with
the SEC, which means that we can disclose information to you by referring you to
those documents. The information incorporated by reference is considered to be
part of this Prospectus, and information that we later file with the SEC will
automatically update the information in this Prospectus.
 
     We incorporate by reference all annual, quarterly and current reports filed
by the Company during 1998. These include the Annual Report on Form 10-K for the
year ended December 31, 1997, the Quarterly Reports on Forms 10-Q filed for the
quarters ended March 31, 1998, June 30, 1998 and September 30, 1998, and the
Current Report on Form 8-K filed on September 24, 1998. We also incorporate by
reference the portions of the Proxy Statement for the annual stockholder meeting
held on May 22, 1998, that were incorporated by reference in the Form 10-K. Any
future annual, quarterly or current reports and proxy materials filed prior to
the end of the Exchange Offer is incorporated by reference.
 
     As a recipient of this Prospectus, you may request a copy of any document
we incorporate by reference, except exhibits to the documents (unless the
exhibits are specifically incorporated by reference), at no cost, by writing or
call us at: Corporate Secretary, America West Airlines, Inc., 51 W. Third
Street, Tempe, Arizona 85281; (602) 693-0800. In order to ensure timely delivery
of the documents, please make any such request no later than five business days
prior to the Expiration Date.
 
                                        2
<PAGE>   4
 
                               TABLE OF CONTENTS
 
<TABLE>
<CAPTION>
                                       PAGE
                                      ------
<S>                                   <C>
PROSPECTUS SUMMARY..................       5
EXCHANGE OFFER......................       5
THE TRUSTS..........................       7
THE CERTIFICATES....................       7
THE EQUIPMENT NOTES.................       9
LIQUIDITY FACILITIES................      11
INTERCREDITOR AGREEMENT.............      11
ERISA CONSIDERATIONS................      12
USE OF PROCEEDS.....................      12
RATIO OF EARNINGS TO FIXED
  CHARGES...........................      13
THE COMPANY.........................      14
QUESTIONS OR REQUESTS FOR
  ASSISTANCE........................      15
CASH FLOW STRUCTURE.................      16
Selected Financial Data.............      17
RISK FACTORS........................      18
Risk Factors Relating to the
  Certificates and the Exchange
  Offer.............................      18
Consequences of Failure to Exchange
  Old Certificates..................      18
Possible Effects if Aircraft
  Appraisals do not Correspond to
  the Realizable Value of
  Aircraft..........................      18
Effect of Subordination on
  Subordinated Certificateholders...      18
Control Over the Collateral and
  Potential Sale of the
  Collateral........................      19
Possible Changes to Agreements
  Described in this Prospectus Post-
  Exchange Offer....................      19
Possible Effects of Appointing Owner
  Participants......................      20
Possible Effects from Unused
  Deposits..........................      20
Effects of Withholding Tax on
  Foreign Investors.................      21
Limited Ability to Resell
  Certificates......................      21
Risk Factors Relating to the Company
  and the Airline Industry..........      21
Competition and Industry
  Conditions........................      21
The Company's Ability to Borrow
  Funds in the Future...............      22
Labor Relations.....................      22
Control by Certain Principal
  Stockholders......................      22
</TABLE>
 
<TABLE>
<CAPTION>
                                       PAGE
                                      ------
<S>                                   <C>
Fluctuations in Fuel Costs..........      23
Aviation Ticket Taxes...............      23
Security and Safety Measures........      23
Other Regulatory Matters............      23
Substantial Restrictions Imposed and
  Promises Made in connection with
  Current Loan Agreements and Debt
  Instruments.......................      24
Year 2000 Compliance Program and
  Risks.............................      24
THE EXCHANGE OFFER..................      26
General.............................      26
The Exchange Offer..................      26
Tendering Old Certificates in the
  Exchange Offer....................      27
Book-Entry Transfer.................      29
Guaranteed Delivery Procedures......      29
Withdrawal of Tenders...............      30
Conditions..........................      30
Exchange Agent......................      30
Transferability of New
  Certificates......................      31
Alternative Use of Shelf
  Registration Statement............      31
Fees and Expenses...................      32
 
DESCRIPTION OF THE NEW
  CERTIFICATES......................      33
General.............................      33
Subordination.......................      34
Payments And Distributions..........      34
Pool Factors........................      37
Reports To Certificateholders.......      39
Indenture Defaults and Certain
  Rights Upon An Indenture
  Default...........................      40
Purchase Rights of
  Certificateholders................      42
PTC Event of Default................      42
Merger, Consolidation And Transfer
  Of Assets.........................      43
Modifications of the Pass Through
  Trust Agreements and Certain Other
  Agreements........................      43
Obligation to Purchase Equipment
  Notes.............................      46
Possible Issuance of Class D
  Certificates......................      48
Liquidation of Original Trusts......      48
</TABLE>
 
                                        3
<PAGE>   5
 
<TABLE>
<CAPTION>
                                       PAGE
                                      ------
<S>                                   <C>
Termination of the Trusts...........      49
The Trustees........................      49
Book-Entry; Delivery And Form.......      50
DESCRIPTION OF THE DEPOSIT
  AGREEMENTS........................      51
General.............................      51
Unused Deposits.....................      51
Distribution Upon Occurrence of
  Triggering Event..................      52
Depositary..........................      53
DESCRIPTION OF THE ESCROW
  AGREEMENTS........................      53
DESCRIPTION OF THE LIQUIDITY
  FACILITIES........................      54
General.............................      54
Drawings............................      54
Reimbursement of Drawings...........      57
Liquidity Events of Default.........      58
Liquidity Provider..................      59
DESCRIPTION OF THE INTERCREDITOR
  AGREEMENT.........................      59
Intercreditor Rights................      59
Priority of Distributions...........      61
Voting of Equipment Notes...........      64
Addition of Trustee for Class D
  Certificates......................      65
The Subordination Agent.............      65
DESCRIPTION OF THE AIRCRAFT AND THE
  APPRAISALS........................      65
The Aircraft........................      65
The Appraisals......................      66
</TABLE>
 
<TABLE>
<CAPTION>
                                       PAGE
                                      ------
<S>                                   <C>
Deliveries of Aircraft..............      66
Substitute Aircraft.................      67
Bridge Financing....................      67
 
DESCRIPTION OF THE EQUIPMENT
  NOTES.............................      67
General.............................      68
Subordination.......................      69
Principal and Interest Payments.....      69
Redemption..........................      69
Security............................      72
Equipment Notes and the Aircraft....      73
Loan to Value Ratios of Equipment
  Notes.............................      73
Limitation of Liability.............      74
Indenture Defaults, Notice and
  Waiver............................      75
Remedies............................      76
Modification of Indentures and
  Leases............................      79
Indemnification.....................      79
The Leases and Certain Provisions of
  the Owned Aircraft Indentures.....      80
 
CERTAIN U.S. FEDERAL INCOME TAX
  CONSEQUENCES......................      88
ERISA CONSIDERATIONS................      88
PLAN OF DISTRIBUTION................      90
LEGAL MATTERS.......................      91
EXPERTS.............................      91
 
APPENDIX I -- INDEX OF TERMS........   A-I-1
APPENDIX II -- APPRAISAL LETTERS....  A-II-1
</TABLE>
 
                                        4
<PAGE>   6
 
                               PROSPECTUS SUMMARY
 
- - THIS SUMMARY HIGHLIGHTS SELECTED INFORMATION FROM THIS PROSPECTUS AND DOES NOT
  CONTAIN ALL OF THE INFORMATION THAT YOU NEED TO CONSIDER IN MAKING YOUR
  INVESTMENT DECISION. TO UNDERSTAND ALL OF THE TERMS OF THE NEW CERTIFICATES,
  READ THE ENTIRE PROSPECTUS AND THE EXHIBITS TO THE REGISTRATION STATEMENT OF
  WHICH THIS PROSPECTUS IS A PART.
 
- - THIS SUMMARY PROVIDES AN OVERVIEW OF CERTAIN FINANCIAL AND OTHER INFORMATION
  AND IS QUALIFIED BY THE FULL DESCRIPTION OF THIS FINANCIAL AND OTHER
  INFORMATION ELSEWHERE IN THIS PROSPECTUS.
 
EXCHANGE OFFER
 
HISTORY
 
In order to finance the purchase of aircraft, America West Airlines, Inc.
("America West" or the "Company") established three America West Airlines 1998-1
Pass Through Trusts (the "Trusts"). The three Trusts are referred to as the
"Class A Trust", the "Class B Trust" and the "Class C Trust".
 
The "Certificates" (which refers to both the Old Certificates and the New
Certificates) represent a fractional undivided interest in one of such Trusts.
The Class A Trust issued "Class A Certificates", the Class B Trust issued "Class
B Certificates" and the Class C Trust issued "Class C Certificates".
 
The Old Certificates were sold in October 1998 pursuant to exemptions from the
SEC registration requirements. The "Initial Purchasers" of the Old Certificates
were Morgan Stanley & Co. Incorporated, Donaldson, Lufkin & Jenrette Securities
Corporation, Merrill Lynch, Pierce, Fenner & Smith Incorporated and Salomon
Smith Barney Inc. The Initial Purchasers then placed the Old Certificates with
institutional investors. The Old Certificates have not been registered with the
SEC and therefore are not freely tradable.
 
The Exchange Offer allows holders of the Old Certificates to exchange their
Certificates for New Certificates. The terms of the New Certificates are
identical in all material respects to the Old Certificates except that the New
Certificates do not have transfer restrictions or interest rate increases and
are available only in book-entry form. See "The Exchange
Offer -- Transferability of New Certificates".
 
The New Certificates are being registered with the SEC pursuant to a
Registration Statement, of which this Prospectus is a part.
 
The New Certificates are being offered in exchange for Old Certificates with the
same principal value. As of the date of this Prospectus, the aggregate principal
amount of Old Certificates outstanding is $190,501,644.22.
 
PROCEDURES
 
Please refer to "The Exchange Offer -- Tendering Old Certificates in the
Exchange Offer".
 
To participate in the Exchange Offer, holders of Certificates
("Certificateholders") must deliver their Old Certificates for exchange no later
than 5:00 p.m., New York time, on             , 1999 (the "Expiration Date").
The Expiration Date may be extended under certain circumstances.
 
Certificateholders must also deliver a completed and signed letter of
transmittal with tender of the Old Certificates (the "Letter of Transmittal"). A
Letter of Transmittal has been sent to Certificateholders and a form can be
found as an exhibit to the Registration Statement.
 
Certificateholders should deliver the Old Certificates and the Letter of
Transmittal to Wilmington Trust Company (the "Exchange Agent") as follows:
 
<TABLE>
<S>           <C>
    Fax:      (302) 651-1079
    Mail or   Wilmington Trust Company
              1100 North Market Street, 1st Fl.
   Overnight  Wilmington, DE 19890-0001
              Attn: Kristin Long
   Delivery:
    By Hand:  Wilmington Trust Company
              1105 North Market Street, 1st Fl.
              Wilmington, DE 19890
              Attn: Corporate Trust Operations
</TABLE>
 
See "The Exchange Offer -- Tendering Old Certificates in the Exchange Offer" and
"-- Exchange Agent".
 
Certificateholders may also tender their Old Certificates through a book-entry
transfer or by complying with certain guaranteed delivery procedures. In either
case, however, a completed Letter
 
                                        5
<PAGE>   7
 
of Transmittal must still be delivered to the Exchange Agent before the
Expiration Date. See "The Exchange Offer -- Tendering Old Certificates in the
Exchange Offer", "-- Book-Entry Transfer" and "-- Guaranteed Delivery
Procedures".
 
DENOMINATIONS
 
Certificateholders may only tender Old Certificates in integral multiples of
$1,000. Similarly, the New Certificates will only be issued in integral
multiples of $1,000.
 
REPRESENTATIONS MADE BY TENDERING CERTIFICATEHOLDERS
 
To participate in the Exchange Offer, each Certificateholder will be required to
make the following representations in the Letter of Transmittal:
 
1. The Certificateholder is not an affiliate of the Company nor a broker-dealer
   tendering Old Certificates acquired for its own account (an "affiliate" is
   defined as a person who controls, is controlled by or is under common control
   with the Company);
 
2. the Certificateholder is acquiring the New Certificates in the ordinary
   course of its business; and
 
3. the Certificateholder is not acquiring the New Certificates with an intent to
   distribute them.
 
RESALE OF NEW CERTIFICATES
 
In connection with the Exchange Offer, the Company is registering the New
Certificates with the SEC in order to remove the transfer restrictions
applicable to the Old Certificates.
 
Certificateholders who make the representations listed above will be able to
freely resell the New Certificates.
 
Certificateholders who are broker-dealers and who acquire New Certificates
directly from the Trustee with an intent to resell them, must deliver a
Prospectus in connection with any resale of New Certificates. The Company will
make this Prospectus available to broker-dealers to use in connection with any
resale of New Certificates for six months following the Expiration Date.
 
For more information on the resale of New Certificates see "The Exchange
Offer -- Transferability of New Certificates".
WITHDRAWAL RIGHTS
 
Certificateholders who have tendered Old Certificates may withdraw such
certificates at any time before 5:00 p.m., New York City time, on the Expiration
Date. To withdraw a tender of Old Certificates, Certificateholders must submit a
written notice requesting such withdrawal to the Exchange Agent. See "Exchange
Offer -- Withdrawal of Tenders".
 
REGISTRATION, CLEARANCE AND SETTLEMENT
 
The New Certificates will be represented by one or more permanent global
certificates, which will be registered in the name of Cede & Co. ("Cede"), as
the nominee of The Depository Trust Company ("DTC"). The global certificates
(the "Global Certificates") will be deposited with the Trustee as custodian for
DTC.
 
See "Description of the New Certificates -- Book Entry; Delivery and Form".
 
DELIVERY OF NEW CERTIFICATES
 
The Exchange Agent will deliver New Certificates for all Old Certificates
promptly following the expiration of the Exchange Offer.
 
TAX CONSEQUENCES
 
The exchange of New Certificates for Old Certificates will not be considered a
sale, exchange or other type of taxable transaction for Federal income tax
purposes. See "Certain Federal Income Tax Considerations".
 
FEES AND EXPENSES
 
The Company will pay for all expenses that arise in connection with the Exchange
Offer.
 
FAILURE TO EXCHANGE OLD CERTIFICATES
 
With some exceptions, Certificateholders who do not exchange their Old
Certificates before the Expiration Date will no longer be entitled to
registration rights. In addition, these Certificateholders will not be able to
offer or sell the Old Certificates unless the Old Certificates are registered
with the SEC or such a sale is exempt from applicable federal and state
securities laws.
 
                                        6
<PAGE>   8
 
THE TRUSTS
 
The three Trusts are as follows:
 
- - America West Airlines 1998-1A Pass Through Trust;
 
- - America West Airlines 1998-1B Pass Through Trust; and
 
- - America West Airlines 1998-1C Pass Through Trust.
 
The Trusts were formed pursuant to one of three separate pass through trust
agreements (the "Pass Through Trust Agreements") entered into between the
Company and Wilmington Trust Company, as "Trustee" of the Trusts.
 
In purchasing the Old Certificates, Certificateholders acquired a fractional
undivided interest in the Trust corresponding with the class of Certificates
purchased. The proceeds from the sale of the Certificates will be used by the
Trustee to purchase equipment notes (the "Equipment Notes") that are expected to
be (or have been) issued in connection with the financing of six Airbus A319-132
aircraft and two Airbus A320-232 aircraft (collectively, the "Aircraft"). "See
Description of the Equipment Notes" and "-- Obligation to Purchase Equipment
Notes".
 
TRUST PROPERTY
 
The property of each Trust (the "Trust Property") consists of the following:
 
1. Equipment Notes issued in connection with the delivery of each Aircraft;
 
2.  rights to acquire Equipment Notes pursuant to a "Note Purchase Agreement"
    among America West and Wilmington Trust Company, as Trustee, subordination
    agent (the "Subordination Agent"), escrow agent (the "Escrow Agent") and
    paying agent (the "Paying Agent");
 
3.  rights under an Escrow and Paying Agent Agreement (the "Escrow Agreement")
    among the Initial Purchasers and the Escrow Agent, the Trustee and the
    Paying Agent (entered into to protect funds in the Deposits (defined below)
    for the benefit of the Certificateholders);
 
4.  rights under an "Intercreditor Agreement" among the Trustee, the
    Subordination Agent and the Liquidity Provider (defined below) (entered into
    to govern the relationships among the different series of
    Certificateholders, the Liquidity Provider and the Subordination Agent);
 
5.  all money to be received under the Liquidity Facility (defined below) for
    such Trust; and
 
6.  funds that may be deposited with the Trustee in accounts relating to such
    Trust.
 
ORIGINAL TRUSTS AND SUCCESSOR TRUSTS
 
The Trusts that were formed in connection with the sale of the Old Certificates
are referred to as the "Original Trusts". On the Transfer Date (defined below),
the Original Trusts will transfer and assign all of their assets and rights to
three substantially identical "Successor Trusts." The difference between these
Trusts is that the Successor Trusts will be governed by New York law (whereas
the Original Trusts are governed by Delaware law) and they will not have the
right to purchase new Equipment Notes.
 
Wilmington Trust Company is Trustee of both the Original Trusts (in such
capacity, the "Original Trustee") and of the Successor Trusts (in such capacity,
the "Successor Trustee").
 
The "Transfer Date" refers to the earlier of (i) the first Business Day after
November 30, 1999, or, if later, the fifth Business Day after the Delivery
Period Termination Date (defined below) and (ii) the fifth Business Day after
the occurrence of a Triggering Event (defined below).
 
THE CERTIFICATES
 
Certificates represent a fractional undivided interest in one of the three
Trusts established by the Company, and are referred to as the "Class A
Certificates", "Class B Certificates" and "Class C Certificates" depending on
which Trust issued them.
 
                                        7
<PAGE>   9
 
                        SUMMARY OF TERMS OF CERTIFICATES
 
The chart below contains information about each Class of Certificates.
 
<TABLE>
<CAPTION>
                            CLASS A         CLASS B         CLASS C
                         CERTIFICATES    CERTIFICATES    CERTIFICATES
                         ------------    ------------    ------------
<S>                      <C>             <C>             <C>
Aggregate Fact Amount..  $131,670,000     $41,154,000     $17,705,000
Ratings:
 Moody's...............       A2             Baa1            Baa3
 Standard & Poor's.....       AA-             A-              BBB
Initial Loan to
 Aircraft Value
 (cumulative)(1).......      42.0%           55.3%           60.4%
Expected Principal
 Distribution Window
 (in years)............    0.7-18.2        1.2-18.2        0.2-11.7
Initial Average Life
 (in years)............      12.7            11.2             7.3
Regular Distribution      Jan. 2 and      Jan. 2 and      Jan. 2 and
 Dates.................     July 2          July 2          July 2
Final Expected Regular
 Distribution Date.....  Jan. 2, 2017    Jan. 2, 2017    July 2, 2010
Final Legal
 Distribution Date.....  July 2, 2018    July 2, 2018    Jan. 2, 2012
Minimum Denomination...    $100,000        $100,000        $100,000
Section 1110 Protec-
 tion(2)...............       Yes             Yes             Yes
                         3 semiannual    3 semiannual    3 semiannual
Liquidity Facility         interest        interest        interest
 Coverage(3)...........    payments        payments        payments
Liquidity Facility
 Amount at Jan. 2,
 2000(3)...............   $14,212,058     $4,642,845      $1,977,379
</TABLE>
 
- -------------------------
    (1) The initial loan to aircraft values for each Class of Certificates were
        determined as of January 2, 2000 and were based on the following
        assumptions:
 
        - all Aircraft will be delivered prior to January 2, 2000;
 
        - the Company will issue the maximum principal amount of Equipment Notes
          with respect to all Aircraft; and
 
        - the aggregate appraised value of all Aircraft will be $306,113,800
          (this value is an estimate and reflects certain assumptions).
 
        See "Description of the Aircraft and the Appraisals -- The Appraisals".
 
        The Company has agreed that all agreements to finance the lease or
        purchase of any Aircraft will have a term requiring that, as of the date
        that an Aircraft is delivered, the initial loan to aircraft value for
        that Aircraft will be no more than the percentages set forth below:
 
<TABLE>
<CAPTION>
   AIRCRAFT FINANCED        MAXIMUM INITIAL LOAN
    WITH RESPECT TO:         TO AIRCRAFT VALUE
   -----------------        --------------------
<S>                         <C>
Series A Equipment Notes             43%
Series B Equipment Notes             57%
Series C Equipment Notes             71%
</TABLE>
 
    (2) After each Aircraft is delivered, the Loan Trustee (defined below) with
        respect to such Aircraft will have the benefit of Section 1110 of the
        U.S. Bankruptcy Code with respect to such Aircraft, which will enable
        such Loan Trustee to take possession of such Aircraft within 60 days of
        the Company's being a debtor under Chapter 11 of the U.S. Bankruptcy
        Code, unless the Company affirms the related Lease or Mortgage financing
        and cures all non-bankruptcy defaults. See "Description of Equipment
        Notes -- Remedies".
 
    (3) If the Company is unable to make regular payments of interest on the
        Equipment Notes, then ABN AMRO Bank N.V., acting through its Chicago
        Branch (the "Liquidity Provider"), will provide for the interest portion
        of such payments for up to three consecutive Scheduled Payments (defined
        below). See "Description of the Certificates -- Payments and
        Distributions".
 
INTEREST
 
Each class of Certificates accrues interest at a different rate set forth below.
 
<TABLE>
<CAPTION>
                                       INTEREST RATE
                                       -------------
<S>                                    <C>
Class A Certificates                       6.87%
Class B Certificates                       7.12%
Class C Certificates                       7.84%
</TABLE>
 
SCHEDULED PAYMENTS
 
Certificateholders will receive Scheduled Payments of interest on each January 2
and July 2, beginning on January 2, 1999. Certificateholders will also receive
Scheduled Payments of principal on each January 2 and July 2 in certain years,
beginning on January 2, 1999. These "Scheduled Payments" will be funded by (1)
interest payments due on the same dates for both the Equipment Notes and the
Deposits (defined below) and (2) principal payments due on the same dates for
the Equipment Notes.
 
If the Company does not make its regular payments of interest on the Equipment
Notes, ABN AMRO Bank N.V., acting through its Chicago branch (the "Liquidity
Provider"), will provide for the interest portion of such payments for up to
three consecutive Scheduled Payments. The "Final Legal Distribution Date" for
each Class of Certificates is the Final Expected Regular Distribution Date for
such Class of Certificates plus eighteen months (being the maximum period
 
                                        8
<PAGE>   10
 
the Liquidity Provider will service interest payments) and is set forth below.
 
<TABLE>
<CAPTION>
                                FINAL LEGAL
                             DISTRIBUTION DATE
                             -----------------
<S>                          <C>
Class A Certificates           July 2, 2018
Class B Certificates           July 2, 2018
Class C Certificates         January 2, 2012
</TABLE>
 
See "Description of the Liquidity Facilities -- Drawings".
 
SPECIAL PAYMENTS
 
Certificateholders may also receive Special Payments if the Company redeems, or
the Trustee purchases, the Equipment Notes from any of the Trusts. Special
Payments, if due, would be made within 20 days of the date that
Certificateholders receive notice that they are entitled to such a payment.
These "Special Payments" will be made up of the principal, interest and, in some
instances, a premium payable by the Company. See "Description of the
Certificates -- Payments and Distributions".
 
METHOD OF DISTRIBUTION
 
Distributions with respect to New Certificates will be made to DTC, who will in
turn distribute the funds to participants in DTC who are credited with ownership
of the New Certificates ("DTC Participants") according to their respective share
of beneficial interests in the New Certificates. The DTC Participants will then
be responsible for distributing all payments to beneficial owners of New
Certificates. See "Description of the New Certificates -- Book-Entry; Delivery
and Form".
 
DEPOSITS
 
The cash proceeds from the sale of the Old Certificates were deposited with ABN
AMRO Bank N.V., acting through its Chicago branch (the "Depositary") and placed
in one of three accounts corresponding to the Trusts that issued the Old
Certificates (such funds being referred to as the "Deposits"). This arrangement
was made pursuant to three separate deposit agreements entered into between the
Depositary and the Escrow Agent (the "Deposit Agreements").
 
When an Aircraft is delivered to the Company during the Delivery Period (defined
below), the Trustee will withdraw funds from the Deposits of the appropriate
Trust to purchase the Equipment Notes of the appropriate series issued with
respect to such Aircraft. The "Delivery Period" runs from October 1998 through
August 1999, with the final delivery for purposes of purchase by the Trusts no
later than November 30, 1999, subject to extension through January 31, 2000
under certain circumstances.
 
Each Deposit accrues interest at an annual rate equal to the annual interest
rate of the Certificates issued by the Trust associated with such Deposit.
Interest accrued on the Deposits will be distributed to Certificateholders on
January 2 and July 2 of each year, beginning on January 2, 1999 and ending when
funds from a Deposit have been fully withdrawn.
 
If any funds remain as Deposits after the Aircraft are financed, such funds will
be distributed to the Certificateholders along with accrued and unpaid interest
and, if applicable, a premium payable by the Company. See "Description of the
Deposit Agreements".
 
PURCHASE RIGHTS OF CERTIFICATEHOLDERS
 
Upon the occurrence of a Triggering Event (defined below), the holders of Class
B Certificates will have a right to purchase all, but not less than all, of the
Class A Certificates; the holders of Class C Certificates will have a right to
purchase all, but not less than all, of the Class A and Class B Certificates;
and, if Class D Certificates are issued, the holders of Class D Certificates
will have a right to purchase all, but not less than all, of the Class A, Class
B and Class C Certificates. "Triggering Event" means (i) the occurrence of an
Indenture Default under all Indentures resulting in a PTC Event of Default
(defined below) with respect to the most senior Class of Certificates, (ii) the
acceleration of all of the outstanding Equipment Notes (provided that during the
Delivery Period the aggregate principal amount exceeds $125,000,000) or (iii)
certain bankruptcy or insolvency events involving the Company. See "Description
of the New Certificates -- Purchase Rights of Certificateholders".
 
THE EQUIPMENT NOTES
 
Equipment Notes will be issued with respect to each financed Aircraft in three
series corresponding to the Trusts that will purchase them. These are referred
to as the "Series A Equipment Notes", the "Series B Equipment Notes" and the
                                        9
<PAGE>   11
 
"Series C Equipment Notes". A Trust will purchase the series of Equipment Notes
that has an interest rate equal to the interest rate of the Certificates issued
by that Trust. See "Description of the Equipment Notes".
 
ISSUANCE OF EQUIPMENT NOTES
 
America West can elect to either purchase or lease an Aircraft, and the
structure of each such financial arrangement is as follows:
 
- - If America West chooses to purchase an Aircraft (an "Owned Aircraft"), then
  America West will issue the Equipment Notes for such Aircraft on a recourse
  basis in connection with a separate secured loan transaction. The Equipment
  Notes will be issued pursuant to an indenture (the "Owned Aircraft Indenture")
  between America West and the indenture trustee thereunder (the "Owned Aircraft
  Trustee").
 
- - If America West chooses to lease an Aircraft (a "Leased Aircraft"), then the
  trustee of a separate owner trust (an "Owner Trustee") established for the
  benefit of an equity investor selected by the Company (the "Owner
  Participant") in a leveraged lease transaction will issue the Equipment Notes
  for such Aircraft on a non-recourse basis in connection with a separate
  leveraged lease transaction for such Aircraft. The Equipment Notes will be
  issued pursuant to an indenture (the "Leased Aircraft Indenture") between the
  applicable Owner Trustee and the indenture trustee thereunder (the "Leased
  Aircraft Trustee").
 
The Leased Aircraft Trustee and Owned Aircraft Trustee are collectively referred
to as the "Loan Trustees". The Leased Aircraft Indentures and the Owned Aircraft
Indentures are collectively referred to as the "Indentures."
 
INTEREST PAYMENTS
 
The Equipment Notes will accrue interest at a rate equal to the annual interest
rate of the Certificates issued by the Trust that purchases them. Interest on
Equipment Notes is payable on January 2 and July 2 of each year, beginning on
January 2, 1999.
 
PRINCIPAL PAYMENTS
 
The Company must also make scheduled principal payments on the Equipment Notes
on January 2 and July 2 of certain years, beginning on January 2, 1999. See
"Description of New Certificates -- Payments and Distributions".
 
MATURITY DATE
 
Equipment Notes will mature on or before the expected final distribution date
for the Certificates issued by the Trusts that own them.
 
REDEMPTION AND PURCHASE
 
If normal use of an Aircraft is disrupted under certain circumstances (see "The
Equipment Notes -- The Leases and Certain Provision of the Owned Aircraft
Indentures" for the definition of an "Event of Loss"), America West must either
replace such Aircraft or redeem the Equipment Notes issued with respect to such
Aircraft. The redemption price in such a case would be equal to the aggregate
unpaid principal amount of such Equipment Notes, together with accrued interest
but without a premium. Under certain other circumstances, America West has the
right to redeem all of the Equipment Notes at a price equal to the aggregate
unpaid principal amount of such notes, together with accrued interest and a
premium (referred to as a "Make-Whole Premium"). Additionally, the Owner Trustee
or an affiliated entity may purchase all of the Equipment Notes issued with
respect to a Leased Aircraft under certain circumstances, including a default by
America West of its lease obligations. See "The Equipment Notes -- Redemption".
 
SECURITY
 
Equipment Notes issued with respect to each Aircraft will be secured by a
security interest in such Aircraft. In the case of a Leased Aircraft, the
corresponding Equipment Notes will also be secured by an assignment of certain
rights under the lease relating to such Aircraft (a "Lease"), including the
right to receive rental payments. In the case of an Owned Aircraft, the
corresponding Equipment Notes will be secured by the mortgage of such Aircraft
and an assignment of certain of America West's rights under its purchase
agreement with the manufacturer of such Aircraft. Each Equipment Note will only
be secured by the Aircraft financed by that Equipment Note and, if
                                       10
<PAGE>   12
 
the Aircraft is leased, by the lease related to that Aircraft, but not by any
other Aircraft or the lease related to any other Aircraft. In addition, any
default that occurs with respect to any Indenture or Lease (with respect to a
Leased Aircraft) will only affect that Indenture or Lease and will not affect
any other Indenture or Lease. See "Description of the Equipment
Notes -- Security".
 
SUBORDINATION
 
The Series C Equipment Notes are subordinate to the Series B Equipment Notes,
which in turn are subordinate to the Series A Equipment Notes. In effect, this
means that on each distribution date the Company must pay interest and principal
due on Series A Equipment Notes before similar payments are made on Series B
Equipment Notes, and the Company must make such payments on Series B Equipment
Notes before similar payments are made on Series C Equipment Notes.
 
If the Company issues Series D Equipment Notes ("Series D Equipment Notes"),
these Notes will be subordinate to the Series C Equipment Notes and the holders
of the Series D Equipment Notes may not receive interest and principal on the
Series D Equipment Notes until such payments on the other three series of notes
are received.
 
POSSIBLE ISSUANCE OF CLASS D EQUIPMENT NOTES
 
The Company may elect to issue Series D Equipment Notes in order to finance the
lease or purchase of additional aircraft. If the Company does so, neither the
Class A, Class B or Class C Trusts would purchase Series D Equipment. The
Company may choose to fund the Series D Equipment Notes through the sale of Pass
Through Certificates (the "Class D Certificates") issued by a Class D America
West Airlines 1998-1 Pass Through Trust (the "Class D Trust").
 
LIQUIDITY FACILITIES
 
The Liquidity Provider will enter into a separate revolving credit agreement (a
"Liquidity Facility") with the Subordination Agent with respect to each class of
Certificates. Under each Liquidity Facility the Liquidity Provider will advance
funds to the Subordination Agent ("Interest Drawings") to be used to pay
interest that is due with respect to Scheduled Payments (described above) on
Certificates if the Company does not meet its payment obligations on the
Equipment Notes.
 
The Liquidity Facilities are intended to enhance the likelihood that
Certificateholders will receive the interest payable on the Certificates in a
timely manner. Interest Drawings may only fund the interest portion of a maximum
of three consecutive Scheduled Payments and may not be used to fund interest
payments on the Deposits, nor principal or premium payments due with respect to
the Certificates.
 
When an Interest Drawing is made under any Liquidity Facility, the Subordination
Agent is obligated to reimburse the Liquidity Provider ahead of the
Certificateholders for the full amount of such drawing (and any other Liquidity
Obligations (as defined below)), to the extent funds are available.
 
"Liquidity Obligations" with respect to each Liquidity Facility include amounts
owed to the Liquidity Provider under that Liquidity Facility and any other
agreements to which the Liquidity Provider is a party, including reimbursements
for any Interest Drawings made under that Liquidity Facility.
 
For more information regarding the Liquidity Facilities, see "Description of the
Liquidity Facilities".
 
INTERCREDITOR AGREEMENT
 
PAYMENT RANKINGS
 
Pursuant to the Intercreditor Agreement between the Trustees, the Subordination
Agent and the Liquidity Provider, in general the Subordination Agent will
distribute regularly scheduled payments received with respect to the Equipment
Notes in the following order:
 
     1.  Liquidity Obligations to the Liquidity Provider;
 
     2.  distributions due to Class A Certificateholders;
 
     3.  distributions due to Class B Certificateholders;
 
     4.  distributions due to Class C Certificateholders;
 
     5.  distributions due to Class D Certificateholders (if any exist); and
 
                                       11
<PAGE>   13
 
     6.  certain fees and expenses to the Subordination Agent and the Trustees.
 
If a Triggering Event occurs, the Intercreditor Agreement provides that the
Subordination Agent will distribute payments received with respect to the
Equipment Notes in the following order:
 
     1.  administrative expenses to the Subordination Agent, the Trustees and
         certain other parties and payment of Liquidity Obligations to the
         Liquidity Provider;
 
     2.  certain fees, taxes, charges and other amounts payable to the
         Subordination Agent, the Trustees and each Certificateholder;
 
     3.  distributions due to holders of Class A Certificates;
 
     4.  distributions due to holders of Class B Certificates;
 
     5.  distributions due to holders of Class C Certificates; and
 
     6.  distributions due to holders of Class D Certificates (if any).
 
See "Description of the Intercreditor Agreement -- Priority of Distributions."
 
Payments made with respect to the Deposits are not subject to the subordination
provisions of the Intercreditor Agreement.
 
INTERCREDITOR RIGHTS
 
In general, holders of a majority of the outstanding principal of Equipment
Notes issued pursuant to a particular Indenture will direct the applicable Loan
Trustee as to whether or not to take certain actions in connection with that
Indenture.
 
If an Indenture Default occurs, until such default is corrected and subject to
certain exceptions, the Controlling Party (defined below) of that Indenture may
accelerate and sell all (but not less than all) of the Equipment Notes issued by
that Indenture.
 
The "Controlling Party" of an Indenture shall mean:
 
     (A) the Class A Trustee;
 
     (B) upon payment of the Final Distributions to the Class A
         Certificateholders, the Class B Trustee; and
     (C) upon payment of the Final Distributions to the Class B
         Certificateholders, the Class C Trustee.
 
If, however, there comes a time when either (1) the entire amount available
under any Liquidity Facility has been withdrawn and has not been reimbursed or
(2) all of the Equipment Notes with respect to any one Indenture have been
accelerated, then 18 months after the earlier of either of the above occurs, the
Liquidity Providers with the highest outstanding amount of Liquidity Obligations
shall have the right to become the Controlling Party with respect to such
Indenture. If such a situation arises, the Trustees and the Certificateholders
are bound to vote as directed by the Controlling Party.
 
Possible actions that the Controlling Party could take include accelerating the
Equipment Notes, foreclosing a lien on the Aircraft securing such Equipment
Notes or, in certain circumstances, selling the Equipment Notes.
 
Because the Equipment Notes are not cross-collateralized, proceeds from the sale
of an Aircraft in excess of the amounts due on Equipment Notes related to such
Aircraft will not be available to cover losses, if any, on any other Equipment
Notes.
 
See "Description of the Intercreditor Agreement -- Intercreditor
Rights -- Controlling Party".
 
ERISA CONSIDERATIONS
 
Subject to important considerations described under "ERISA Considerations" in
this Prospectus, the Class A Certificates are eligible for purchase by persons
investing assets of employee benefit plans or individual retirement accounts and
the Class B Certificates and Class C Certificates are not so eligible.
 
USE OF PROCEEDS
 
There will be no cash proceeds payable to America West as a result of the
issuance of New Certificates pursuant to the Exchange Offer. Proceeds from the
sale of the Old Certificates were deposited with the Depositary for the benefit
of the Certificateholders of the Trusts. These proceeds will be used to purchase
Equipment Notes. See "Use of Proceeds".
                                       12
<PAGE>   14
 
RATIO OF EARNINGS TO FIXED CHARGES
 
The following information for the year ended December 31, 1993 and for the
period from January 1, 1994 through August 25, 1994 relates to America West's
predecessor. Information for the period August 26, 1994 through December 31,
1994, for the years ended December 31, 1995, 1996 and 1997 and for the nine
months ended September 30, 1997 and 1998 relates to America West. The
information as to America West has not been prepared on a consistent basis of
accounting with the information as to the predecessor due to America West's
adoption in August 1994 of fresh start reporting in accordance with the American
Institute of Certified Public Accountants' Statement of Position 90-7 --
"Financial Reporting by Entities in Reorganization Under the Bankruptcy Code
("SOP 90-7").
 
For the year ended December 31, 1993, the ratio of earnings to fixed charges was
1.28. For the period from January 1, 1994 through August 25, 1994, $201.2
million would have been required to achieve a ratio of earnings to fixed charges
of 1.0. The ratio of earnings to fixed charges for the period August 26, 1994 to
December 31, 1994, and for the years ended December 31, 1995, 1996 and 1997, was
1.38, 1.73, 1.24 and 1.98, respectively. The ratio of earnings to fixed charges
for the nine months ended September 30, 1997 and September 30, 1998 was 1.98 and
2.35, respectively.
 
For the purpose of computing the ratio of earnings to fixed charges, "earnings"
consist of income (loss) before income taxes and extraordinary item plus fixed
charges less capitalized interest. "Fixed charges" consist of interest expense
including amortization of debt expense, one-third of rent expense, which is
deemed to be representative of an interest factor, and capitalized interest.
 
                                       13
<PAGE>   15
 
THE COMPANY
 
We are the ninth largest commercial airline carrier in the United States,
operating through our principal hubs located in Phoenix, Arizona and Las Vegas,
Nevada, and a mini-hub located in Columbus, Ohio. We are the lowest cost major
airline in the United States. At the end of 1997, we served 60 destinations,
including six destinations in Mexico and one in Canada, with a fleet of 102
aircraft. We offered service to an additional 32 destinations through alliance
arrangements with other airlines.
 
We seek to maximize our market share by operating primarily through our hub
airports. We are the leading airline serving Phoenix, Las Vegas and Columbus,
based on available seat miles. We believe that the success of our operations in
Phoenix and Las Vegas is in part due to those cities' airports being among the
world's largest 25 in passenger numbers and those cities being among the fastest
growing in the nation. In addition, we believe that our hubs are well positioned
for continued growth due to their geographically favorable locations with
strategic access to key Southwest and West Coast markets, relatively low
operating costs, year-round fair weather and modern, uncongested facilities.
 
We are committed to maintaining the airline's reliability and providing quality
customer service. During 1997, we initiated a Pride in All We Do campaign aimed
at improving our baggage handling, on-time performance and all other aspects of
our customer service. As a result of initiatives developed by this program, our
mishandled baggage rate during 1997, as recorded by the Department of
Transportation, was the best in the industry. In addition, we were ranked No. 1
in customer satisfaction among the major United States airlines for short-haul
flights in both the 1997 and the 1998 Airline Customer Satisfaction -- U.S.
Flights studies, which was conducted by Frequent Flyer Magazine and J.D. Power &
Associates.
 
BUSINESS STRATEGY
 
Our strategy is to maximize profitability and cash flow by capitalizing on our
key competitive strengths while maintaining financial flexibility. The principal
elements of our strategy are to expand our existing lines of business, to
maintain our strategic cost advantage and to ensure financial flexibility.
 
Grow the Company's Existing Lines of Business
 
We intend to expand our airline operation by continuing to add service to new
destinations and increasing the frequency of flights to existing destinations
from Phoenix and Las Vegas. The Phoenix and Las Vegas markets are among the
fastest growing in the United States, and we believe that our Phoenix hub is
undersized relative to its potential. During 1996 and 1997 we added eight new
cities to our route network and increased the frequency of flights to our key
business markets.
 
We have also expanded our reach outside of our core markets through alliances
with other airlines. We have codesharing arrangements with Continental Airlines,
Northwest Airlines and British Airways as well as a commuter agreement with
Mesa. These alliances have allowed us to expand our passenger base without
experiencing significant increases in capital or operating expenses, and in some
cases it has allowed us to achieve cost savings by reducing redundant labor and
facilities. We believe that these alliances are an efficient means of developing
new markets and increasing travel opportunities for our customers and we plan to
continue to pursue such relationships with both domestic and international
carriers.
 
Maintain its Strategic Cost Advantage
 
We are committed to maintaining our low cost structure, which offers us a
significant competitive advantage over other major airlines. We have achieved
this low cost structure primarily through employee productivity, favorable labor
costs per available seat mile and industry-leading aircraft utilization.
 
Ensure Financial Flexibility
 
The airline and travel industries are cyclical in nature. Because of this, an
important element of our strategy is to maintain financial flexibility as
protection against a downturn in the business cycle. A key component of this
strategy is our aircraft leasing plan. As of the end of 1997, leases for 24
aircraft are scheduled to expire at the end of 2001. As a result, if economic
conditions worsen during that period, we will be able to delay
 
                                       14
<PAGE>   16
 
our fleet and aircraft-related financial obligations by electing not to renew
these aircraft leases or otherwise replace these aircraft. Another component of
this strategy is our compensation system, which gives us the flexibility to vary
what we pay employees depending on our overall performance. In December 1997, we
further enhanced our financial flexibility by establishing a $100 million senior
secured revolving credit facility with certain financial institutions.
 
America West is a Delaware corporation. Our executive offices are located at 51
W. Third Street, Tempe, Arizona 85281, and our telephone number is (602)
693-0800.
 
America West Holdings Corporation ("Holdings") is a Delaware corporation that
became the holding company for America West effective midnight December 31,
1996. The only material assets of Holdings are the capital stock of America West
and the capital stock of The Leisure Company ("LeisureCo."), a travel and
leisure subsidiary.
 
RECENT DEVELOPMENTS
 
On January 20, 1999, Holdings reported record earnings for the fourth quarter
and full year 1998. Excluding non-recurring charges of $3.7 million, Holdings'
fourth quarter net income was $22.4 million -- 11 percent above the previous
record of $20.1 million in 1997. America West reported fourth quarter pre-tax
earnings of $30.7 million and record 1998 pre-tax income of $184.6 million, up
44.2 percent over 1997.
 
On January 20, 1999, Holdings reported that it had been contacted by a number of
airlines expressing interest in possible transactions ranging from a strategic
alliance to a merger or similar business combination. There can be no assurance
that Holdings will engage in discussions or enter into an agreement with any
other company regarding a possible transaction.
 
QUESTIONS OR REQUESTS FOR ASSISTANCE
 
If you have questions or would like to request assistance with the mechanics of
exchanging your Old Certificates in the Exchange Offer, please direct them to
Wilmington Trust Company as indicated below. In addition to the other positions
described in this Prospectus Summary, Wilmington Trust Company has been
appointed to act as the Exchange Agent of the Exchange Offer.
 
     By Mail or Overnight Delivery:
 
     Wilmington Trust Company
     1100 North Market Street
     Wilmington, Delaware 19890-0001
     Attention: Kristin Long
 
     By Hand:
 
     Wilmington Trust Company
     1105 North Market Street, 1st Floor
     Wilmington, Delaware 19890
     Attention: Corporate Trust Operations
 
     By Facsimile Transmission*:
 
     (302) 651-1079
 
          *Confirm successful delivery by telephone at (302) 651-1562
 
                                       15
<PAGE>   17
 
                              CASH FLOW STRUCTURE
 
Set forth below is a diagram illustrating the structure for the Certificates and
                              certain cash flows.
 
                          [CASH FLOW STRUCTURE CHART]
 
(1) Each Leased Aircraft will be subject to a separate Lease and the related
    Indenture; each owned Aircraft will be subject to a separate Indenture.
 
(2) Funds held as Deposits relating to each Trust will be withdrawn to purchase
    Equipment Notes on behalf of such Trust during the Delivery Period. If any
    funds remain as Deposits with respect to any Trust at the end of such
    period, such funds will be withdrawn by the Escrow Agent and distributed to
    the holders of the Certificates issued by such Trust, together with accrued
    and unpaid interest thereon and a premium, if applicable. No interest will
    accrue with respect to the Deposits after they have been fully withdrawn.
 
(3) The initial amount of the Liquidity Facility for each Trust will cover three
    consecutive semiannual interest payments with respect to such Trust, except
    that the Liquidity Facility for any Trust will not cover interest payable by
    the Depositary on the Deposits relating to such Trust. The scheduled
    payments of interest on the Equipment Notes and on the Deposits relating to
    a Trust, taken together, will be sufficient to pay an amount equal to
    accrued interest on the outstanding Certificates issued by such Trust at the
    rate per annum applicable thereto.
 
                                       16
<PAGE>   18
 
                            SELECTED FINANCIAL DATA
 
     The following selected financial data as of and for the years ended
December 31, 1997, 1996 and 1995, the period August 26 through December 31,
1994, and the period January 1 through August 25, 1994 and the year ended
December 31, 1993 are derived from the financial statements of the Company which
have been audited by KPMG LLP, independent certified public accountants. The
selected financial data should be read in conjunction with the financial
statements for the respective periods, the related notes and the independent
auditors' reports incorporated by reference into this Prospectus. The financial
data of the Company for the nine months ended September 30, 1998 and 1997 is
derived from its unaudited financial statements incorporated by reference in
this Prospectus.
<TABLE>
<CAPTION>
                                                      REORGANIZED COMPANY
                       ----------------------------------------------------------------------------------
                             NINE MONTHS
                         ENDED SEPTEMBER 30,           YEAR ENDED DECEMBER 31,             PERIOD FROM
                       -----------------------   ------------------------------------     AUGUST 26 TO
                          1998         1997         1997         1996         1995      DECEMBER 31, 1994
                       ----------   ----------   ----------   ----------   ----------   -----------------
                             (UNAUDITED)               (DOLLARS IN THOUSANDS EXCEPT OPERATING DATA)
<S>                    <C>          <C>          <C>          <C>          <C>          <C>
STATEMENT OF
  OPERATIONS DATA:
Operating revenues...  $1,475,866   $1,402,065   $1,874,956   $1,739,526   $1,550,642      $  469,766
Operating income.....     163,062      121,030      162,573       68,666(1)    154,732(2)        38,871
Income before income
  taxes and
  extraordinary
  items..............     153,873      104,286      140,673       34,493      108,378          19,736
Income before
  extraordinary
  items..............      83,874       54,855       75,330        9,610       54,770           7,846
Extraordinary
  items(3)...........          --           --           --       (1,105)        (984)             --
Net income...........      83,874       54,855       75,330        8,505       53,786           7,846
BALANCE SHEET DATA
  (AT END OF PERIOD):
Working capital
  deficiency.........  $ (149,230)  $ (160,909)  $ (161,456)  $ (170,907)  $  (70,416)     $  (47,927)
Total assets.........   1,622,212    1,540,204    1,547,331    1,597,677    1,588,709       1,545,092
Long-term debt, less
  current
  maturities.........     214,933      271,266      272,760      330,148      373,964         465,598
Total stockholders'
  equity.............     753,675      664,293      684,768      622,780      649,472         595,446
OPERATING DATA
  (UNAUDITED):
Available seat miles
  (in millions)......      18,070       17,618       23,568       21,625       19,421           6,424
Revenue passenger
  miles (in
  millions)..........      12,340       12,339       16,204       15,321       13,313           3,972
Passenger load factor
  (%)................        68.3         70.0         68.8         70.9         68.5            61.8
Yield per revenue
  passenger mile
  (cents)............       11.30        10.70        10.89        10.69        10.91           11.02
Passenger revenue per
  available seat mile
  (cents)............        7.72         7.49         7.49         7.57         7.48            6.81
Operating cost per
  available seat mile
  (cents)............        7.27         7.32(4)       7.27        7.73(1)       7.19(2)          6.71
Fulltime equivalent
  employees (at end
  of period).........       9,881        9,521        9,615        9,652        8,712          10,715
 
<CAPTION>
                            PREDECESSOR COMPANY
                       ------------------------------
 
                         PERIOD FROM      YEAR ENDED
                        JANUARY 1 TO     DECEMBER 31,
                       AUGUST 25, 1994       1993
                       ---------------   ------------
 
<S>                    <C>               <C>
STATEMENT OF
  OPERATIONS DATA:
Operating revenues...     $939,028        $1,325,364
Operating income.....      107,506           121,054
Income before income
  taxes and
  extraordinary
  items..............     (201,209)           37,924
Income before
  extraordinary
  items..............     (203,268)           37,165
Extraordinary
  items(3)...........      257,660                --
Net income...........       54,392            37,165
BALANCE SHEET DATA
  (AT END OF PERIOD):
Working capital
  deficiency.........     $     --        $ (124,375)
Total assets.........           --         1,016,743
Long-term debt, less
  current
  maturities.........           --           620,992
Total stockholders'
  equity.............           --          (254,262)
OPERATING DATA
  (UNAUDITED):
Available seat miles
  (in millions)......       11,636            17,190
Revenue passenger
  miles (in
  millions)..........        8,261            11,221
Passenger load factor
  (%)................         71.0              65.3
Yield per revenue
  passenger mile
  (cents)............        10.68             11.11
Passenger revenue per
  available seat mile
  (cents)............         7.58              7.25
Operating cost per
  available seat mile
  (cents)............         7.15              7.01
Fulltime equivalent
  employees (at end
  of period).........       10,849            10,544
</TABLE>
 
- -------------------------
(1) Reflects a $65.1 million nonrecurring special charge relating to America
    West's renegotiation of its AVSA S.A.R.L., an affiliate of Airbus Industries
    ("AVSA") aircraft purchase agreement and writedown of certain aircraft
    related inventory and equipment and underutilized facilities as well as
    certain other adjustments. The special charge increased cost per available
    seat mile by .30 cents for the year ended December 31, 1996.
 
(2) Costs associated with America West's outsourcing of its heavy aircraft
    maintenance resulted in a pretax restructuring charge of approximately $10.5
    million and an increase in cost per available seat mile of .05 cents for the
    year ended December 31, 1995.
 
(3) Includes (i) an extraordinary loss of $1.1 million in 1996 relating to
    prepayment of the 10 3/4% Notes, (ii) an extraordinary loss of $984,000 in
    1995 resulting from the exchange of debt by America West and (iii) $257.7
    million in 1994 resulting from the discharge of indebtedness pursuant to the
    consummation of the plan of reorganization.
 
(4) Operating cost per seat mile for the nine months ended September 30, 1997 is
    based on pro forma numbers.
 
                                       17
<PAGE>   19
 
                                  RISK FACTORS
 
RISK FACTORS RELATING TO THE CERTIFICATES AND THE EXCHANGE OFFER
 
CONSEQUENCES OF
FAILURE TO EXCHANGE
OLD CERTIFICATES       If you do not exchange Old Certificates for New
                       Certificates in this Exchange Offer, you will be
                       restricted from transferring Old Certificates in the
                       future. In general, outside of this Exchange Offer, you
                       may not offer or sell Old Certificates unless they have
                       been registered under the federal and state securities
                       laws or you offer or sell them in a transaction that is
                       exempt from such laws. The Company is not planning to
                       register the Old Certificates under the federal
                       securities laws.
 
POSSIBLE EFFECTS IF
AIRCRAFT APPRAISALS
DO NOT CORRESPOND
TO THE REALIZABLE
VALUE OF AIRCRAFT      Aviation Solutions, Inc. ("AvSolutions"), AVITAS, Inc.
                       ("AVITAS") and BK Associates, Inc. ("BK") (collectively,
                       the "Appraisers") have appraised the Aircraft being
                       acquired by the Company. These appraisals were based on
                       various assumptions and methodologies, which differed
                       among the Appraisers.
 
                       In general, the appraised value of each Aircraft was
                       calculated using the average or median value of an
                       Aircraft, whichever was lower, and then that value was
                       projected for the month in which the Aircraft is
                       scheduled to be delivered. In addition, the Appraisers
                       assumed depreciation of approximately 3% for Aircraft
                       delivered more than one year before the Delivery Period
                       Termination Date.
 
                       An appraisal is only an estimate of value and is not
                       necessarily an accurate indication of how much the
                       Company will pay to purchase an Aircraft. Appraisals
                       based on different assumptions and methodologies than
                       those used by the Appraisers may produce very different
                       values for the Aircraft. In addition, the realizable
                       value of the Aircraft following the exercise of remedies
                       will depend on several factors including:
 
                          - supply of other aircraft
                          - quality of other aircraft available
                          - supply of buyers
                          - general economic conditions
                          - condition of the Aircraft
 
                       Accordingly, you should not rely on the appraisal values
                       as an indicator of the value that would be realized if
                       the Aircraft are sold. Based on the above, we cannot
                       assure you that the proceeds from a sale or other means
                       of disposal of an Aircraft will be sufficient to fully
                       fund payments due to Certificateholders.
 
                       See "Description of the Aircraft and the
                       Appraisals -- The Appraisals".
 
EFFECT OF
SUBORDINATION ON
SUBORDINATED
CERTIFICATEHOLDERS     Payments on the subordinated classes of Certificates will
                       not be made until the senior classes are paid those
                       amounts due to them. In addition, in certain
                       circumstances, if the Company has defaulted on a series
                       of Equipment Notes, the Subordination Agent may be
                       required to distribute payments received with respect to
                       a more junior series of Equipment Notes to those
                       Certificateholders that were due to receive payments with
                       respect to the Equipment Notes on which the default
                       occurred. In such a situation the remaining junior series
                       of Equipment Notes may not earn enough interest to fully
                       fund distributions due to the holders of the
                       corresponding Certificates. Accordingly, if the Company
                       defaults on Equipment Notes, the holders of one or more
                       junior Classes of Certificates may not receive the full
                       amount of payments that they are due to receive, even if
                       the Company eventually pays the Equipment Notes due in
                       full.
                                       18
<PAGE>   20
 
                       Payment with respect to the Deposits are not subject to
                       the subordination provisions of the Intercreditor
                       Agreement.
 
CONTROL OVER THE
COLLATERAL AND
POTENTIAL SALE OF THE
COLLATERAL             The "Controlling Party" of an Indenture shall mean:
 
                         (a) the Class A Trustee;
                         (b) upon payment of the Final Distributions to the
                             Class A Certificateholders, the Class B Trustee;
                             and
                         (c) upon payment of the Final Distributions to the
                             Class B Certificateholders, the Class C Trustee.
 
                       If there comes a time when either (1) the entire amount
                       available under any Liquidity Facility has been withdrawn
                       and has not been reimbursed or (2) all of the Equipment
                       Notes with respect to any one Indenture have been
                       accelerated, then 18 months after the earlier of either
                       of the above occurs, the Liquidity Provider with the
                       highest outstanding amount of Liquidity Obligations shall
                       have the right to become the Controlling Party with
                       respect to such Indenture. If such a situation arises,
                       the Trustees and the Certificateholders are bound to vote
                       as directed by the Controlling Party.
 
                       Possible actions that the Controlling Party could take
                       include accelerating the Equipment Notes, foreclosing a
                       lien on the Aircraft securing such Equipment Notes or, in
                       certain circumstances, selling the Equipment Notes.
 
                       Because the Equipment Notes are not cross-collateralized,
                       proceeds from the sale of an Aircraft in excess of the
                       amounts due on Equipment Notes related to such Aircraft
                       will not be available to cover losses, if any, on any
                       other Equipment Notes.
 
                       From time to time, the market for Equipment Notes may be
                       very limited and there can be no assurance that the
                       proceeds from such an acceleration or sale will be
                       sufficient to cover the distributions payable to
                       Certificateholders. If proceeds from a sale are
                       insufficient to cover distributions due to be paid,
                       Certificateholders will not have any claim for the
                       shortfall against the Company, any Owner Trustee, Owner
                       Participant or any Trustee.
 
                       For a description of the restrictions on the right of the
                       Controlling Party to sell the Equipment Notes see
                       "Description of the New Certificates -- Indenture
                       Defaults and Certain Rights Upon and Indenture Default".
 
POSSIBLE CHANGES TO
AGREEMENTS
DESCRIBED IN THIS
PROSPECTUS POST-
EXCHANGE OFFER
                       Listed below are certain situations that, should they
                       occur, could lead to revisions of certain agreements
                       described in this Prospectus, such that those agreements
                       would differ from their descriptions in this Prospectus.
 
                       Leveraged Lease Financing of an Aircraft
 
                       If an Aircraft is to be financed using a leveraged lease,
                       the Company must select an Owner Participant for such
                       Aircraft. Such Owner Participant will have the right to
                       request that revisions be made to the following
                       documents:
 
                          - Participation Agreement;
                          - Lease; and
                          - Leased Aircraft Indenture.
 
                       Issuance of Series D Equipment Notes
 
                       If the Company issues Series D Equipment Notes and funds
                       the sale of such notes by selling Class D Certificates,
                       the parties that purchase Class D
 
                                       19
<PAGE>   21
 
                       Certificates will have the right to request that
                       revisions be made to the following documents:
 
                          - Leased Aircraft Documents;
                          - Form of the Participation Agreement; and
                          - Form of Owned Aircraft Indenture.
 
                       Regardless of the revisions requested, certain terms of
                       the documents are subject to the following restrictions:
 
                          - Mandatory Documents Terms must be included; and
                          - Mandatory Economic Terms may not be revised.
 
                       In addition, if any revisions are requested, the Company
                       must do the following:
 
                          1. Certify to the Trustees that any revisions made to
                             documents do not materially and adversely affect
                             the Certificateholders; and
 
                          2. In case of any material revisions, obtain written
                             confirmation from each of Moody's Investors
                             Service, Inc. ("Moody's") and Standard & Poor's
                             Ratings Services ("Standard & Poor's", and together
                             with Moody's, the "Rating Agencies") that the
                             revisions made to documents will not cause the
                             withdrawal, suspension or downgrading of the rating
                             of any Class of Certificates.
 
                       See "Description of the Certificates -- Obligation to
                       Purchase Equipment Notes".
 
POSSIBLE EFFECTS OF
APPOINTING OWNER
PARTICIPANTS
                       As stated above, if an Aircraft is to be financed
                       utilizing a leveraged lease, the Company must select an
                       Owner Participant with respect to such Aircraft. In
                       addition to having the right to request that revisions be
                       made to certain documents, prior to an Indenture Default
                       an Owner Participant will have the right to approve the
                       selection of counsel that, pursuant to the documentation,
                       will furnish legal opinions, and any appraisers or the
                       accountants required by the documentation. This right is
                       to the exclusion of the related Loan Trustee.
 
                       An Owner Participant will also have the right to approve
                       the sublease of an Aircraft and to approve of the bill of
                       sale used if an Aircraft is ever substituted after an
                       event of loss.
 
                       Finally, an Owner Participant will have the right to
                       sell, assign or otherwise transfer its interest in any
                       leverage lease, subject to the relevant Participation
                       Agreement and related documents.
 
POSSIBLE EFFECTS
FROM UNUSED
DEPOSITS
                       There is no guarantee that the Trustees will have an
                       opportunity to use all of the funds in the Deposits to
                       purchase Equipment Notes. The Trustees will not be
                       obligated to purchase Equipment Notes if certain
                       conditions are not satisfied when an Aircraft is
                       delivered. See "Description of the New
                       Certificates -- Obligation to Purchase Equipment Notes".
                       In addition the Company may not issue enough Equipment
                       Notes to use up the funds in the Deposits.
 
                       The Trustees will withdraw all funds that remain as
                       Deposits at the Delivery Period Termination Date and
                       distribute them with accrued and unpaid interest. In
                       certain circumstances, but not all, the Company will also
                       be required to pay a premium designed to "make-whole" the
                       Certificateholders receiving such Deposits. Since the
                       maximum principal amount of Equipment Notes may not be
                       issued with respect to an Aircraft and, in any such case,
                       the
                                       20
<PAGE>   22
 
                       Series C Equipment Notes are more likely not to be issued
                       in the maximum principal amount as compared to the other
                       Equipment Notes, it is more likely that a distribution of
                       unused Deposits will be made with respect to the Class C
                       Certificates as compared to the other Certificates. See
                       "Description of the Deposit Agreements -- Unused
                       Deposits".
 
EFFECTS OF
WITHHOLDING TAX ON
FOREIGN INVESTORS
                       Taxes will be withheld from distributions made with
                       respect to Original Trusts and Deposits that are made to
                       foreigners that have beneficial ownership of
                       Certificates. Such taxes will be withheld because of the
                       possibility that the Original Trusts may be treated as
                       partnerships engaged in U.S. trades or businesses for
                       U.S. federal income tax purposes.
 
                       By accepting an interest in a Certificate, foreign
                       investors must agree to indemnify the Original Trustee,
                       the Original Trust and the Paying Agent against liability
                       for improperly failing to withhold tax.
 
                       Foreign investors may file a U.S. federal income tax
                       return to request refunds for any amounts withheld, but
                       there is no assurance that they will receive such a
                       refund or that such refunds will be received in a timely
                       manner.
 
LIMITED ABILITY TO
RESELL CERTIFICATES
                       Prior to the Exchange Offer, there was no public market
                       for the Certificates. Certain Initial Purchasers
                       previously made a market in the Old Certificates and have
                       indicated that they intend to make a market in the New
                       Certificates, but they are not required to do so.
                       Accordingly, a secondary market for the Certificates may
                       not develop and even if one does, it might not continue
                       or it might not be sufficiently liquid to allow you to
                       resell any of your Certificates.
 
RISK FACTORS RELATING TO THE COMPANY AND THE AIRLINE INDUSTRY
 
Below we have listed certain risks that we face as a business in general. If any
of these risks actually have a material adverse effect on our business,
financial condition or operating results, we may not be able to satisfy some or
all or our obligations under the Leases (in the case of Leased Aircraft) or the
Equipment Notes (in the case of Owned Aircraft). Depending on the extent to
which we are unable to satisfy these obligations, you may not realize the
expected return on your investment in the Certificates, and in the worst case,
you may not get back the full amount of your initial investment in the
Certificates.
 
COMPETITION AND
INDUSTRY CONDITIONS
                       The airline industry is highly competitive and industry
                       earnings are typically volatile. From 1990 to 1992, the
                       airline industry experienced unprecedented losses due to
                       high fuel costs, general economic conditions, intense
                       price competition and other factors. Airlines compete on
                       the basis of pricing, scheduling (frequency and flight
                       times), on-time performance, frequent flyer programs and
                       other services.
 
                       The airline industry is susceptible to price discounting,
                       which occurs when a carrier offers discounts or
                       promotional fares to passengers. Discounted fares offered
                       by one carrier are normally matched by competing
                       carriers, which may have the effect of lowering the
                       profit per passenger but not necessarily increase the
                       number of passengers who fly. In addition, in recent
                       years several new carriers have entered the airline
                       industry, and many of them have low-cost structures. In
                       some cases, these new carriers have initiated or
                       triggered price discounting. The entry of additional new
                       carriers in many of our markets, as well as increased
                       competition from or the introduction of new services by
                       existing carriers, could have a material adverse effect
                       on our business, financial condition and operating
                       results.
 
                       Most of the markets we serve are highly competitive and
                       are served by larger carriers with substantially greater
                       financial resources than we have available.
                                       21
<PAGE>   23
 
                       At our Phoenix and Las Vegas hubs, our principal
                       competitor is Southwest Airlines. A number of our larger
                       competitors have proprietary reservation systems, which
                       gives them certain competitive advantages.
 
                       The air travel business historically fluctuates in
                       response to general economic conditions. The airline
                       industry is sensitive to changes in economic conditions
                       that affect business and leisure travel and is highly
                       susceptible to unforeseen events that result in declines
                       in air travel, including:
 
                         - political instability
 
                         - regional hostilities
 
                         - recession
 
                         - fuel price escalation
 
                         - inflation
 
                         - adverse weather conditions
 
                       If the rates of travel on the routes that we serve
                       decrease or if competition increases between carriers,
                       our business, financial condition and operating results
                       could be materially adversely affected.
 
THE COMPANY'S
ABILITY TO BORROW
FUNDS IN THE FUTURE
                       As of September 30, 1998, we owed approximately $215
                       million of long-term debts (less current maturities).
                       Much of this debt is secured by a large portion of our
                       assets, leaving us with a limited number of assets to use
                       to obtain additional financing which we may need if we
                       encounter adverse industry conditions or a prolonged
                       economic recession in the future.
 
                       In addition, as of September 30, 1998, we had firm
                       commitments to AVSA to purchase a total of 29 Airbus
                       aircraft with three to be delivered in the fourth quarter
                       of 1998 and had an option to purchase 52 more Airbus
                       aircraft. The aggregate net cost of firm commitments
                       remaining under the purchase order is approximately $1.0
                       billion, based on a 3.5 percent annual price escalation.
                       We have arranged for financing from AVSA for more than
                       two-thirds of these commitments, but we will have to look
                       to outside sources to finance the remaining commitments.
                       We cannot guarantee that we will be able to obtain enough
                       capital to finance the remainder of the aircraft, and if
                       we default on our commitments to purchase aircraft, our
                       business, financial condition and operating results could
                       be materially adversely affected.
 
LABOR RELATIONS
                       In the recent past, labor unions have made several
                       attempts to organize our employees, and we expect that
                       these efforts will continue. Certain groups of our
                       employees have chosen to be represented by a union and we
                       are currently negotiating initial collective bargaining
                       agreements with some of these groups. We cannot predict
                       which, if any, other groups of employees may seek union
                       representation or the outcome of collective bargaining
                       agreements that we may be forced to negotiate in the
                       future. If we are unable to negotiate acceptable
                       collective bargaining agreements, we might have to wait
                       through "cooling off" periods, which could be followed by
                       union-initiated work actions, including strikes.
                       Depending on the type and duration of work action we
                       endure, our business, financial condition and operating
                       results could be materially adversely affected.
 
CONTROL BY CERTAIN
PRINCIPAL
STOCKHOLDERS
                       As of December 31, 1998, four stockholders collectively
                       control approximately 55% of the total voting power of
                       America West Holdings Corporation, our parent corporation
                       ("Holdings"). These stockholders are TPG Partners, L.P.,
                                       22
<PAGE>   24
 
                       TPG Parallel I, L.P., Air Partners II, L.P. and
                       Continental Airlines, Inc. TPG, TPG Parallel and Air
                       Partners are all controlled by the same company, TPG
                       Advisors, Inc. We cannot guarantee that the controlling
                       stockholders identified above will not try to influence
                       Holding's business in a way that would favor their own
                       personal interests to the detriment of our interests.
 
FLUCTUATIONS IN FUEL
COSTS
                       Fuel is an important raw material used in our business,
                       accounting for approximately 11% of our total operating
                       expenses in 1998. With our current level of fuel
                       consumption, if jet fuel prices increase by one cent per
                       gallon, our annual operating results will decrease by
                       $4.4 million for 1999. Among the unpredictable events
                       whose occurrence could effect the price and supply of jet
                       fuel in the future are:
 
                          - geopolitical developments
                          - regional production patterns
                          - environmental concerns
 
                       In 1996, we implemented a fuel "hedging" program to
                       manage the possible effect that fluctuating jet fuel
                       prices could have on our business. The program primarily
                       addresses our exposure to fuel requirements on the East
                       Coast. West Coast jet fuel prices, however, tend to be
                       more volatile than jet fuel prices in other areas of the
                       United States and because we primarily serve the Western
                       United States, we purchase a substantially larger portion
                       of our jet fuel requirements on the West Coast compared
                       to our larger competitors.
                       Accordingly, if the price of jet fuel goes up
                       substantially or the supply of jet fuel is inadequate in
                       the future and we have not implemented adequate
                       protection measures, our business, financial condition
                       and operating results could be materially adversely
                       affected.
 
AVIATION TICKET
TAXES
                       On August 5, 1997 President Clinton signed a new aviation
                       ticket tax into law that is scheduled to stay in effect
                       though September 30, 2007. As a result of the competitive
                       environment in the passenger airline industry, we have
                       been limited in our ability to pass on the additional
                       costs of these taxes to passengers through fare
                       increases.
 
SECURITY AND SAFETY
MEASURES
                       Congress has adopted increased safety measures designed
                       to increase airline passenger security and protect
                       against terrorist acts. Implementing these measures has
                       increased operating costs for the airline industry as a
                       whole. A report from Congress' Aviation Safety Commission
                       recommends that airlines implement additional measures to
                       improve the safety and security of air travel. We cannot
                       predict which additional measures Congress will impose or
                       the impact that implementing those measures will have on
                       our revenue, but it is possible that the impact could be
                       significant.
 
OTHER REGULATORY
MATTERS
                       The airline industry in heavily regulated. Both federal
                       and state governments from time to time propose laws and
                       regulations that would impose additional requirements and
                       restrictions on airline operations. Depending on which
                       and how many of these laws and regulations are enacted,
                       the cost of operating an airline could increase
                       significantly. We cannot predict what laws and
                       regulations will be adopted or the changes and increased
                       expense that they could cause. Accordingly, future
                       legislative and regulatory acts could have a materially
                       adverse effect on our business, financial conditions or
                       operating results.
 
                                       23
<PAGE>   25
 
SUBSTANTIAL
RESTRICTIONS
IMPOSED AND
PROMISES MADE IN
CONNECTION WITH
CURRENT LOAN
AGREEMENTS AND
DEBT INSTRUMENTS
                       We have borrowed money pursuant to certain loan
                       agreements and debt instruments with significant
                       operating and financial restrictions. These agreements
                       and instruments contain terms that may significantly
                       restrict or prohibit our ability to take certain actions,
                       including our ability:
 
                          - to repay certain debts before they come due
                          - to sell assets
                          - to participate in certain mergers and acquisitions
                          - to conduct future financings
                          - to make needed capital expenditures
                          - to implement certain measures that would better
                            enable us to withstand future downturns in the
                            airline industry or the economy in general
 
                       In addition, several of these borrowing arrangements
                       require us to satisfy certain benchmarks in respect of
                       our financial position.
 
                       We are currently in compliance with the restrictions and
                       requirements referred to above, but any default would
                       allow our lenders to require us to repay the full amount
                       of money that we have borrowed, plus accrued and unpaid
                       interest. If this were to occur, we cannot guarantee that
                       we would have or be able to raise the funds needed to pay
                       off these debts.
 
                       Finally, we may be obligated to offer to purchase certain
                       amounts of the debts referred to above. Such obligations
                       would arise if certain changes occur with respect to who
                       controls us or Holdings, our parent company, or if we
                       dispose of certain assets.
 
YEAR 2000
COMPLIANCE
PROGRAM AND RISKS
                       The Year 2000 issue results from computer programs being
                       written using two digits rather than four to define the
                       applicable year. As a consequence, time-sensitive
                       computer equipment and software may recognize a date
                       using "00" as the year 1900 rather than the year 2000.
                       Many of the Company's systems, including information and
                       computer systems and automated equipment, will be
                       affected by the Year 2000 issue. The Company is also
                       heavily reliant on the FAA's management of the nation's
                       air traffic control system, local authorities' management
                       of the airports at which AWA operates, and vendors to
                       provide goods (fuel, catering, etc.), services
                       (telecommunications, data networks, satellites, etc.) and
                       data (frequent flyer partnerships, alliances, etc.).
 
                       The Company has underway a Year 2000 Project (the
                       "Project" or "Year 2000 Project") to identify the
                       programs and infrastructure that could be affected by the
                       Year 2000 issue and is implementing a plan to resolve the
                       problems identified on a timely basis. The Project
                       requires the Company to devote a considerable amount of
                       internal resources and hire substantial external
                       resources to assist with the implementation and
                       monitoring of the Project, and will require the
                       replacement of certain equipment and modification of
                       certain software.
 
                       The Company believes that its Year 2000 Project will be
                       completed prior to any currently anticipated significant
                       impact on the Company arising from the Year 2000 issue.
                       The Project is divided into three main sections,
                       including information technology ("IT") systems, embedded
                       systems and third party compliance. The five phases of
                       the IT and embedded systems sections include inventory,
                       assessment, renovation, user testing and implementation.
                       The inventory and assessment phases of the IT systems are
                       substantially completed and the remaining phases of the
                       IT systems are expected to be completed in the first and
                       second quarters of 1999. The inventory phase of the
                       embedded
 
                                       24
<PAGE>   26
 
                       systems is substantially completed and the remaining
                       phases are underway and are expected to be completed
                       during the first, second and third quarters of 1999.
 
                       The Company currently estimates that the total cost of
                       its Year 2000 Project will be approximately $40 million,
                       which will be funded from operating cash flows. These
                       costs exclude approximately $7 million of normal system
                       software and equipment upgrades and replacements which
                       the Company anticipated incurring in the ordinary course
                       regardless of the Year 2000 issue. As of December 31,
                       1998, the Company had incurred approximately $13 million
                       of non-capital expenditures in connection with the Year
                       2000 Project. The Company expects that approximately $30
                       million of the costs have been or will be expensed as
                       incurred and the Company has had or will have
                       approximately $10 million of capital expenditures.
 
                       The costs and expected completion date of the Company's
                       Year 2000 Project are based on management's best
                       estimates, and reflect assumptions regarding the
                       availability and cost of personnel trained in this area,
                       the compliance plans of third parties and similar
                       uncertainties. However, due to the complexity and
                       pervasiveness of the Year 2000 issue and in particular
                       the uncertainty regarding the compliance programs of
                       third parties, no assurance can be given that these
                       estimates will be achieved, and actual results could
                       differ materially from those anticipated. If the
                       Company's plan to address the Year 2000 issue is not
                       successfully or timely implemented, the Company may need
                       to devote more resources to the process and additional
                       costs may be incurred, which could have a material
                       adverse effect on the Company's financial condition and
                       results of operations.
 
                       The failure to correct a material Year 2000 problem could
                       result in an interruption in, or failure of, certain
                       normal business activities or operations. While difficult
                       to predict, the Company speculates that the most
                       reasonably likely worst case Year 2000 scenario will
                       result from the failure of third parties, including
                       operators of airports and air traffic control systems, to
                       resolve their Year 2000 compliance issue. The Company has
                       initiated communications with such parties and its
                       significant suppliers and vendors with which its systems
                       interface and upon which the Company's business depends
                       in an effort to reduce the adverse impact of the Year
                       2000 issue. There can be no assurance, however, that the
                       systems of such third parties will be modified on a
                       timely basis and such failure may have a material adverse
                       effect on the Company's financial condition and results
                       of operations.
 
                       As a component of its Year 2000 Project, the Company is
                       developing a comprehensive analysis of the operational
                       problems and costs (including loss of revenues) that
                       would be reasonably likely to result from the failure by
                       the Company and certain third parties to complete efforts
                       necessary to achieve Year 2000 compliance on a timely
                       basis. The Company is developing contingency plans
                       designed to enable it to continue operations, consistent
                       with the highest standards of safety, in the event of
                       such third party failures.
 
                                       25
<PAGE>   27
 
                               THE EXCHANGE OFFER
 
     This section summarizes key provisions of the Exchange and Registration
Rights Agreement among America West, the Trustees and the Initial Purchasers
(the "Registration Rights Agreement"), which has been filed as an exhibit to the
Registration Statement and is available as set forth under the heading
"Available Information".
 
GENERAL
 
     Pursuant to the Registration Rights Agreement, America West agreed, at no
cost to the holders of the Certificates, to register the Certificates with the
SEC to allow holders to trade the Certificates. Such a registration (a
"Registration Event") would take one of two forms set forth below:
 
     Registration Event
 
     (1) Exchange Offer Registration Statement. An Exchange Offer under the
         Securities Act of 1933, as amended (the "Securities Act") would allow
         holders to exchange the Old Certificates for New Certificates, which
         will have terms identical in all material respects to the Old
         Certificates (except that the New Certificates will not contain terms
         with respect to transfer restrictions or interest rate increases as
         described below and the New Certificates will be available only in
         book-entry form).
 
     (2) Shelf Registration Statement. Alternatively, in the event that any
         changes in law or applicable interpretations of the staff of the SEC
         would not permit America West to effect the Exchange Offer, or the
         Exchange Offer is not consummated within 210 days after the initial
         issuance date of the Certificates, which was October 6, 1998 (the
         "Issuance Date"), holders who are not eligible to participate in the
         Exchange Offer could request that the Company register the Old
         Certificates for resale under the Securities Act through a shelf
         registration statement (the "Shelf Registration Statement").
 
     If the Company is unable to consummate the Exchange Offer or,
alternatively, to have a Shelf Registration Statement declared effective within
210 calendar days of October 6, 1998, the interest rate per annum on the
Equipment Notes and Deposits will be increased by 0.50% from the 210th day until
either the Exchange Offer is consummated, a shelf registration statement is
declared effective or the date on which all of the outstanding Certificates are
transferable by holders (other than affiliates or former affiliates of America
West) without further registration under the Securities Act.
 
     If during any 12-month period the shelf registration statement ceases to be
effective for more than 60 days, whether or not consecutive, the interest rate
per annum on the Equipment Notes and the Deposits will be increased by 0.50%
from the 61st day the shelf registration statement ceases to be effective until
the shelf registration statement again becomes effective.
 
THE EXCHANGE OFFER
 
     In the Registration Rights Agreement the Company agreed to register New
Certificates with the SEC to allow holders of all outstanding Old Certificates
to exchange their Old Certificates for the New Certificates. The New
Certificates will have the same material financial terms as the Old
Certificates. The difference between the Certificates is that the New
Certificates will not contain terms with respect to transfer restrictions or
interest rate increases and the New Certificates will be available only in
book-entry form. This Prospectus, together with the Letter of Transmittal, is
being sent to all registered holders of Old Certificates as of
[               ], for the purpose of allowing holders to exchange their Old
Certificates.
 
     Obligations of the Company to Effect an Exchange Offer
 
     (1) File a registration statement to register the New Certificates by
         February 3, 1999.
 
     (2) Cause the registration statement to become effective by April 4, 1999.
 
                                       26
<PAGE>   28
 
     (3) Keep the registration statement effective while the Exchange Offer is
         open, which must be no fewer than 30 days.
 
     (4) Complete the Exchange Offer by May 4, 1999.
 
     The Exchange Offer will commence upon effectiveness of the registration and
terminate 30 calendar days after the Exchange Offer commences, unless extended.
The Company has the sole discretion to extend the Exchange Offer by notifying
the Exchange Agent and mailing an announcement of the extension to the holders
of Old Certificates. However, if the Exchange Offer is not consummated by May 4,
1999, the interest rate on the Equipment Notes and Deposits is subject to
increase. See "-- General".
 
     The Company has the right to delay acceptance of any Old Certificates in
the Exchange Offer, to extend the Exchange Offer or to terminate the Exchange
Offer and not permit acceptance of Old Certificates not previously accepted if
any of the conditions set forth herein under "-- Conditions" occur. The Company
can also amend the terms of the Exchange Offer in any manner it deems
advantageous to the holders of the Old Certificates. The Company will notify the
Exchange Agent as promptly as practicable in the event of any delay in
acceptance, extension, termination or amendment. If the Exchange Offer is
amended in a manner determined by the Company to constitute a material change,
the Company will promptly disclose such amendment in a manner reasonably
calculated to inform the holders of the Old Certificates of such amendment. The
Company has no obligation to publish, advertise, or otherwise communicate any
such public announcement, other than by making a timely release to an
appropriate news agency.
 
     With some exceptions, holders of Old Certificates who do not exchange their
Old Certificates for New Certificates in the Exchange Offer will no longer be
entitled to registration rights and will not be able to offer or sell their Old
Certificates, unless such Old Certificates are subsequently registered under the
Securities Act or pursuant to a transaction exempt from the Securities Act and
applicable state securities laws. After the Exchange Offer is consummated, with
some limited exceptions, the Company will not be required to subsequently
register the Old Certificates.
 
TENDERING OLD CERTIFICATES IN THE EXCHANGE OFFER
 
     Only a holder of Old Certificates may tender such Old Certificates in the
Exchange Offer. The term "holder" with respect to the Exchange Offer means any
person in whose name Old Certificates are registered on the books of the Company
or any other person who has obtained a properly completed bond power from the
registered holder. Any beneficial owner of Old Certificates registered in the
name of a broker, dealer, commercial bank, trust company or other nominee who
wishes to tender should contact such registered holder promptly and instruct
such registered holder to tender on his behalf. If a beneficial owner wants to
tender on his own behalf, he must, prior to completing and executing the Letter
of Transmittal and delivering his Old Certificates, either make appropriate
arrangements to register ownership of the Old Certificates in his name or obtain
a properly completed bond power from the registered holder. The transfer of
registered ownership may take considerable time.
 
     Subject to certain conditions (set forth under "-- Conditions"), the
Company will accept for exchange all Old Certificates validly tendered and not
withdrawn prior to 5:00 p.m., New York City time, on the date the exchange offer
expires. Old Certificates may be tendered only in integral multiples of $1,000.
There is no minimum principal amount of Old Certificates that must be tendered
in order for the Exchange Offer to take place. The tender by a holder of Old
Certificates will constitute an agreement between the holder and the Company in
accordance with the Letter of Transmittal.
 
     Upon satisfaction or waiver of all of the conditions to the Exchange Offer,
all Old Certificates properly tendered will be accepted and the New Certificates
will be issued promptly after acceptance of the Old Certificates. The Exchange
Agent will act as agent for the tendering holders of Old Certificates for the
purposes of receiving the New Certificates and delivering New Certificates to
such holders. Any such New Certificates issued will be of the same class and for
an equal face amount as the Old
 
                                       27
<PAGE>   29
 
Certificates tendered. For purposes of the Exchange Offer, Old Certificates will
be deemed to have been accepted for exchange when, as and if the Company has
given oral or written notice thereof to the Exchange Agent.
 
     Requirements for Tendering Old Certificates in the Exchange Offer
 
     (1) Complete, sign and date the Letter of Transmittal or a facsimile
         thereof.
 
        (a) Guaranteed Signatures May Be Required. Signatures on a Letter of
            Transmittal or a notice of withdrawal, as the case may be, must be
            guaranteed by any member firm of a registered national securities
            exchange or of the National Association of Securities Dealers, Inc.,
            a commercial bank or trust company having an office or correspondent
            in the United States or an "eligible guarantor" institution within
            the meaning of Rule 17Ad-15 under the Exchange Act unless the Old
            Certificates are tendered by a registered holder who has not
            completed the box entitled "Special Issuance Instructions" or
            "Special Delivery Instructions" on the Letter of Transmittal or for
            the account of an Eligible Institution.
 
        (b) Bond Powers May be Required. If the Letter of Transmittal is signed
            by a person other than the registered holder of any Old Certificates
            listed therein, such Old Certificates must be endorsed or
            accompanied by bond powers and a proxy which authorizes such person
            to tender the Old Certificates on behalf of the registered holder,
            in each case as the name of the registered holder or holders appears
            on the Old Certificates.
 
        (c) Fiduciaries Should Identify Themselves. If the Letter of Transmittal
            or any Old Certificates or bond powers are signed by trustees,
            executors, administrators, guardians, attorneys-in-fact, officers of
            corporations or others acting in a fiduciary or representative
            capacity, such persons should so indicate when signing, and unless
            waived by the Company, evidence satisfactory to the Company of their
            authority to so act must be submitted with the Letter of
            Transmittal.
 
     (2) Mail or otherwise deliver the completed Letter of Transmittal, and any
         other items noted below, to the Exchange Agent by 5:00 p.m., New York
         City time, on or before the date the Exchange Offer expires. No items
         should be sent to the Company. See "-- Exchange Agent" below.
 
     (3) Any of the three methods discussed below can be used to deliver the
         certificates representing the Old Certificates to the Exchange Agent on
         or before the date the Exchange Offer expires. The method of delivery
         is up to the holder, who bears the risk of non-delivery.
 
        (a) Send the actual certificates representing the Old Certificates to
            the Exchange Agent with the Letter of Transmittal. If delivery is by
            mail, insured registered mail is recommended.
 
        (b) If available, make a book-entry delivery of the Old Certificates
            into the Exchange Agent's account at DTC. See "-- Book-Entry
            Transfer" below. Certain brokers, dealers, commercial banks, trust
            companies and other nominees who hold Old Certificates through DTC
            must tender their certificates in this way. Beneficial owners of Old
            Certificates registered in the name of a broker, dealer, commercial
            bank, trust company or other nominee are urged to contact such
            person promptly if they wish to tender Old Certificates pursuant to
            the Exchange Offer.
 
        (c) Holders who cannot deliver their Old Certificates or who cannot
            complete the procedures for delivery by book-entry transfer of the
            Old Certificates on or before the date the Exchange Offer expires,
            must, in order to participate in the Exchange Offer, tender their
            Old Certificates according to the guaranteed delivery procedures set
            forth below under "-- Guaranteed Delivery Procedures".
 
     All questions as to the validity, form, eligibility (including time of
receipt) and withdrawal of the tendered Old Certificates will be determined by
the Company in its sole discretion, which determination will be final and
binding. The Company reserves the absolute right to reject any and all Old
Certificates if they are not properly tendered or are unlawful in the opinion of
counsel for the Company. Unless waived
 
                                       28
<PAGE>   30
 
by the Company, any defects or irregularities in connection with tenders of Old
Certificates must be cured within such time as the Company determines. The
Company's interpretation of the terms and conditions of the Exchange Offer
(including the instructions in the Letter of Transmittal) will be final and
binding on all parties.
 
     Neither the Company, the Exchange Agent nor any other person is under any
duty to notify holders of Old Certificates of defects or irregularities
regarding tenders of Old Certificates, nor shall any of them be liable for
failure to give such notification. Tenders of Old Certificates will not be
deemed to have been made until such irregularities have been cured or waived.
Any Old Certificates received by the Exchange Agent that are not properly
tendered or cured of defects or irregularities will be returned to the holder by
the Exchange Agent, without cost to the holder, as soon as practicable following
the Expiration Date.
 
     In addition, subject to some limitations, the Company reserves the right to
purchase or make offers for any Old Certificates that remain outstanding after
the Exchange Offer expires, to terminate the Exchange Offer, and to purchase Old
Certificates in the open market to the extent permitted by applicable law. The
terms of any such purchases or offers could differ from the terms of the
Exchange Offer.
 
BOOK-ENTRY TRANSFER
 
     For purposes of the Exchange Offer, the Exchange Agent will establish an
account with respect to the Old Certificates at DTC within two Business Days
after the date of this Prospectus. Any tendering financial institution that is a
participant in DTC's book-entry transfer facility system must make a book-entry
delivery of the Old Certificates by causing DTC to transfer such Old
Certificates into the Exchange Agent's account in accordance with DTC's
Automated Tender Offer Program ("ATOP") procedures for transfers. Such holder of
Old Certificates using ATOP should transmit its acceptance to DTC on or prior to
the Expiration Date (or comply with the guaranteed delivery procedures set forth
below). DTC will verify such acceptance, execute a book-entry transfer of the
tendered Old Certificates into the Exchange Agent's account at DTC and then send
to the Exchange Agent confirmation of such book-entry transfer, including an
agent's message confirming that DTC has received an express acknowledgment from
such holder that such holder has received and agrees to be bound by the Letter
of Transmittal and that the Trust and America West may enforce the Letter of
Transmittal against such holder.
 
GUARANTEED DELIVERY PROCEDURES
 
     If a registered holder of the Old Certificates desires to tender such Old
Certificates, and the Old Certificates are not immediately available, or time
will not permit such holder's Old Certificates or other required documents to
reach the Exchange Agent before the Expiration Date, or the procedures for book
entry transfer cannot be completed on a timely basis, a tender may be effected
under the procedures set forth here. This procedure can only be handled by a
member firm of a registered national securities exchange or of the National
Association of Securities Dealers, Inc., a commercial bank or trust company
having an office or correspondent in the United States or an "eligible
guarantor" institution within the meaning of Rule 17Ad-15 under the Exchange Act
(each an "Eligible Institution"). Prior to the expiration of the Exchange Offer,
the Company must receive from an Eligible Institution a properly completed and
duly executed Letter of Transmittal (or a facsimile thereof) and a Notice of
Guaranteed Delivery, substantially in the form provided by the Company (by
facsimile transmission, mail or hand delivery). The Notice of Guaranteed
Delivery must set forth the name and address of the holder of Old Certificates,
the amount of Old Certificates tendered and a statement guaranteeing that within
three trading days of the execution of the notice the certificates for all
tendered Old Certificates (or a book-entry confirmation) will be deposited by
the Eligible Institution with the Exchange Agent. Actual delivery of such Old
Certificates (or a book-entry confirmation) within such three day period is
required.
 
                                       29
<PAGE>   31
 
WITHDRAWAL OF TENDERS
 
     Tenders of Old Certificates may be withdrawn by a holder at any time prior
to 5:00 p.m., New York City time on the date the Exchange Offer expires by
notifying the Exchange Agent in writing. A notice of withdrawal must specify the
name of the person having tendered the Old Certificates to be withdrawn,
identify the Old Certificates to be withdrawn (including the principal amount of
such Old Certificates) and if the certificates for Old Certificates were
transmitted, specify the name in which such Old Certificates are registered, if
different from that of the withdrawing holder. If certificates for Old
Certificates were delivered to the Exchange Agent, then, prior to the release of
such certificates, the withdrawing holder must also submit the serial numbers of
the particular certificates to be withdrawn and a signed notice of withdrawal.
The signatures on the notice of withdrawal must be guaranteed by an Eligible
Institution unless such holder is an Eligible Institution. If Old Certificates
were tendered pursuant to the procedure for book-entry transfer, any notice of
withdrawal must specify the name and number of the account at the book-entry
transfer facility to be credited with the withdrawn Old Certificates and
otherwise comply with the procedures of such facility.
 
     The Company will have final and binding authority to determine all
questions as to the validity, form and eligibility (including time of receipt)
of notices of withdrawal. Any Old Certificates so withdrawn will be deemed not
to have been validly tendered for exchange for purposes of the Exchange Offer.
Any Old Certificates which were tendered for exchange but which were not
exchanged for any reason will be returned to the holder thereof without cost to
such holder as soon as practicable after withdrawal. Old Certificates which were
tendered by book-entry transfer into the Exchange Agent's account at the book-
entry transfer facility will be credited to an account maintained with the
book-entry transfer facility for the Old Certificates as soon as practicable
after withdrawal. Properly withdrawn Old Certificates may be retendered
following the procedures described above at any time on or prior to the date the
Exchange Offer expires.
 
CONDITIONS
 
     The Company will not be required to accept any Old Certificates for
exchange and the Company may terminate or amend the Exchange Offer before the
acceptance of Old Certificates, if the Company determines that it is not
permitted to effect the Exchange Offer because of any change in law or
applicable interpretations thereof by the SEC. In addition, the Company will
have no obligation to, and will not knowingly, accept tenders of Old
Certificates from affiliates of the Company (within the meaning of Rule 405
under the Securities Act) or from any other holder who is not eligible to
participate in the Exchange Offer under applicable law or interpretations
thereof by the SEC, or if the New Certificates to be received by such holder in
the Exchange Offer would not be tradable by such holder without restriction
under the Securities Act and the Exchange Act and without material restrictions
under the "blue sky" or securities laws of substantially all of the states of
the United States.
 
EXCHANGE AGENT
 
     Wilmington Trust Company has been appointed as Exchange Agent for the
Exchange Offer. Questions and requests for assistance and requests for
additional copies of this Prospectus or of the Letter of Transmittal should be
directed to the Exchange Agent addressed as follows:
 
<TABLE>
<S>                                            <C>
        By Mail or Overnight Delivery:                            By Hand:
           Wilmington Trust Company                       Wilmington Trust Company
           1100 North Market Street                 1105 North Market Street, 1st Floor
       Wilmington, Delaware 19890-0001                   Wilmington, Delaware 19890
           Attention: Kristin Long                 Attention: Corporate Trust Operations
                                                          Facsimile Transmission:
                                                               (302) 651-1079
                                                           Confirm by Telephone:
                                                               (302) 651-1562
</TABLE>
 
                                       30
<PAGE>   32
 
TRANSFERABILITY OF NEW CERTIFICATES
 
     Based on interpretations by the staff of the SEC (noted below), the Company
believes that most holders of New Certificates will be able to offer for resale,
re-sell or otherwise transfer the New Certificates issued without compliance
with the registration and prospectus delivery requirements of the Securities
Act, provided that the New Certificates are acquired in the ordinary course of
such holders' business and such holders are not engaged in, and do not intend to
engage in, a distribution of such New Certificates and have no arrangement with
any person to participate in a distribution of the New Certificates.
Broker-dealers who acquired Old Certificates directly from the Trustee for
resale under an exemption under the Securities Act, or any holder that is an
"affiliate" of the Company (as defined in Rule 405 of the Securities Act) must
comply with the registration and prospectus delivery requirements of the
Securities Act.
 
     The SEC staff interpretations relied on are set forth in no-action letters
issued to third parties, including Exxon Capital Holdings Corporation, SEC
No-Action Letter (available April 13, 1989), Morgan Stanley & Co., Incorporated,
SEC No-Action Letter (available June 5, 1991) and Shearman & Sterling, SEC
No-Action Letter (available July 2, 1993).
 
     Other than broker-dealers and affiliates, holders who wish to tender their
Old Certificates in the Exchange Offer will be required to make certain
representations to the Company in the Letter of Transmittal.
 
     Representations Required by Holders to Tender Old Certificates in Exchange
Offer
 
     (1) Such holder is not an affiliate of the Company (as defined under Rule
         405 of the Securities Act) nor a broker-dealer tendering Old
         Certificates acquired directly from the Company for its own account.
 
     (2) The holder will acquire the New Certificates in the ordinary course of
         its business.
 
     (3) The holder is not engaged in, and does not intend to engage in, a
         distribution of the New Certificates and has no arrangement or
         understanding to participate in a distribution of the New Certificates.
 
     Each broker-dealer that receives New Certificates for its own account
pursuant to the Exchange Offer must acknowledge that it will deliver a
prospectus in connection with any resale of such New Certificates. By so
acknowledging and by delivering a prospectus, the broker-dealer will not be
deemed to admit that it is an "underwriter" within the meaning of the Securities
Act. This Prospectus, as it may be amended or supplemented from time to time,
may be used by a broker-dealer in connection with resales of New Certificates
where the broker-dealer acquired the exchanged Old Certificates as a result of
market-making activities or other trading activities. The Company agrees to make
copies of this Prospectus available to such broker-dealers for 180 days after
the Exchange Offer expires. See "Plan of Distribution."
 
ALTERNATIVE USE OF SHELF REGISTRATION STATEMENT
 
     If changes in the law or other circumstances do not allow America West to
effect the Exchange Offer, America West will, upon request of a holder not
eligible to participate in the Exchange Offer or under certain other
circumstances described in the Registration Rights Agreement, file a shelf
registration statement to allow resales of the Old Certificates.
 
     Obligations of the Company if the Shelf Registration Statement Alternative
is Pursued
 
     (1) File with the SEC as soon as practicable a shelf registration statement
         covering resales of the Old Certificates.
 
     (2) Use its best efforts to have the shelf registration statement declared
         effective within 180 calendar days of October 6, 1998.
 
                                       31
<PAGE>   33
 
     (3) Use its best efforts to keep the shelf registration statement effective
         for two years after it is declared effective (or a such shorter period
         if all of the Old Certificates covered by the shelf registration
         statement have been sold or are freely transferable under Rule 144 of
         the Securities Act).
 
FEES AND EXPENSES
 
     The expenses of soliciting tenders pursuant to the Exchange Offer will be
borne by the Company. The principal solicitation for tenders is being made by
mail; however, additional solicitations may be made by telegraph, telephone,
telecopy, electronic mail or in person by officers and regular employees of the
Company. Other expenses incurred in connection with the Exchange Offer will be
paid by the Company, including fees and expenses of the Exchange Agent and
Trustee and accounting, legal, printing and related fees and expenses.
 
     The Company will not make any payments to brokers, dealers or other persons
soliciting acceptances of the Exchange Offer. The Company, however, will pay the
Exchange Agent reasonable and customary fees for its services and will reimburse
the Exchange Agent for its reasonable out-of-pocket expenses in connection
therewith. The Company may also pay brokerage houses and other custodians,
nominees and fiduciaries the reasonable out-of-pocket expenses incurred by them
in forwarding copies of the Prospectus and related documents to the beneficial
owners of the Old Certificates, and in handling or forwarding tenders for
exchange.
 
     The Company will pay all transfer taxes, if any, applicable to the exchange
of Old Certificates pursuant to the Exchange Offer. Certain other transfer taxes
may be imposed on the tendering holder unless satisfactory evidence of payment
of such taxes or exemption therefrom is not submitted with the Letter of
Transmittal.
 
                                       32
<PAGE>   34
 
                      DESCRIPTION OF THE NEW CERTIFICATES
 
     The New Certificates will be issued pursuant to three separate Pass Through
Trust Agreements. The following summary describes certain of the Certificates,
the Deposits and the Pass Through Trust Agreements but does not purport to be
complete. Reference is made to all of the provisions of the Pass Through Trust
Agreements, the Deposit Agreements, the Escrow Agreements and the Intercreditor
Agreement, which have been filed as exhibits to the Registration Statement and
which are available as set forth under the heading "Available Information".
 
     Except as otherwise indicated, the following summary relates to each of the
Trusts and the Certificates issued by each Trust. The terms and conditions
governing each of the Trusts are substantially the same, except as described
under "-- Subordination" below and except that the principal amount and
scheduled principal repayments of the Equipment Notes held by each Trust and the
interest rate and maturity date of the Equipment Notes held by each of the Class
A Trust, the Class B Trust and the Class C Trusts will differ.
 
     The references to Sections in parentheses in the following summary are to
the relevant Sections of the Pass Through Trust Agreements unless otherwise
indicated.
 
GENERAL
 
     The New Certificates of each Trust will be issued in fully registered form
only and will be subject to the provisions described below under "-- Book Entry;
Delivery and Form". (Section 3.01) Each New Certificate will represent a
fractional undivided interest in the Trust created by the Pass Through Trust
Agreement pursuant to which such Certificate is issued. (Section 3.01) The Trust
Property of each Trust consists of the items listed below:
 
     Trust Property for Each Trust
 
     (1) Equipment Notes acquired under the Note Purchase Agreement and issued,
         at America West's election in connection with the delivery of each
         Aircraft during the Delivery Period, either (a) on a non-recourse basis
         by an Owner Trustee in each separate leveraged lease transaction with
         respect to each Leased Aircraft to finance the purchase of such Leased
         Aircraft by the Owner Trustee, in which case the applicable Leased
         Aircraft will be leased to America West, or (b) on a recourse basis by
         America West in connection with each separate secured loan transaction
         with respect to each Owned Aircraft to finance the purchase of such
         Owned Aircraft by America West.
 
     (2) The rights of such Trust to acquire Equipment Notes under the Note
         Purchase Agreement.
 
     (3) The rights of such Trust under the applicable Escrow Agreement
         (including the right to request the Escrow Agent to withdraw from the
         Depositary funds sufficient to enable such Trust to purchase Equipment
         Notes on the delivery of each Aircraft during the Delivery Period).
 
     (4) The rights of such Trust under the Intercreditor Agreement (including
         all monies receivable in respect of such rights).
 
     (5) All monies receivable under the Liquidity Facility for such Trust.
 
     (6) Funds from time to time deposited with the Trustee in accounts relating
         to such Trust. The New Certificates represent pro rata shares of the
         Equipment Notes and other property held in the related Trust and will
         be issued only in minimum denominations of $1,000 and integral
         multiples thereof. (Section 3.01(a) and 3.01(b)).
 
     On the Transfer Date, each of the Original Trusts will transfer and assign
all of its assets and rights to a substantially identical Successor Trust, and
the Successor Trustee will assume the obligations of the related Original
Trustee under each transaction document to which such Original Trustee was a
party. Upon the effectiveness of such transfer, assignment and assumption, each
of the Original Trusts will be liquidated and each of the Certificates will
represent the same interest in the Successor Trust as it
                                       33
<PAGE>   35
 
represented in the Original Trust immediately prior to such transfer, assignment
and assumption. Unless the context otherwise requires, all references in this
Prospectus to the Trusts, the Trustees, the Pass Through Trust Agreements and
similar terms shall be applicable to the Original Trusts until the effectiveness
of such transfer, assignment and assumption and thereafter shall be applicable
with respect to the Successor Trusts. See "-- Liquidation of Original Trusts".
 
     The Certificates represent interests in the respective Trusts, and all
payments and distributions thereon will be made only from the Trust Property of
the related Trust. (Section 3.11) The Certificates do not represent an interest
in or obligation of America West, the Trustees, any of the Loan Trustees or
Owner Trustees in their individual capacities, any Owner Participant, or any
affiliate of any thereof.
 
     Pursuant to the Escrow Agreement applicable to each Trust, the
Certificateholders of such Trust as holders of the Escrow Receipts affixed to
each Certificate are entitled to certain rights with respect to the Deposits
relating to such Trust. Accordingly, any transfer of a Certificate will have the
effect of transferring the corresponding rights with respect to the Deposits,
and rights with respect to the Deposits may not be separately transferred by
Certificateholders. Rights with respect to the Deposits and the Escrow Agreement
relating to a Trust, except for the right to request withdrawals for the
purchase of Equipment Notes, do not constitute Trust Property of such Trust.
 
SUBORDINATION
 
     Pursuant to the Intercreditor Agreement to which the Trustees, the
Subordination Agent and the Liquidity Provider are parties, on each Distribution
Date, so long as no Triggering Event shall have occurred (whether or not
continuing), all payments received by the Subordination Agent in respect of
Equipment Notes and certain other payments will be distributed in the order set
forth in "Description of the Intercreditor Agreement -- Priority of
Distributions -- Priority of Distributions in the Absence of a Triggering
Event." In addition, upon the occurrence of a Triggering Event and at all times
thereafter, all payments received by the Subordination Agent in respect of the
Equipment Notes and certain other payments will be distributed under the
Intercreditor Agreement in the order set forth in "Description of the
Intercreditor Agreement -- Priority of Distributions -- Priority of
Distributions in the Event of a Triggering Event."
 
     The priority of distributions after a Triggering Event will have the effect
in certain circumstances of requiring the distribution to more senior Classes of
Certificates of payments received in respect of one or more junior series of
Equipment Notes. If this should occur, the interest accruing on the remaining
Equipment Notes would in the aggregate be less than the interest accruing on the
remaining Certificates because such Certificates include a relatively greater
proportion of junior Classes with relatively higher interest rates. As a result
of such possible interest shortfalls, the holders of one or more junior Classes
of Certificates may not receive the full amount due them after a Triggering
Event even if all Equipment Notes are eventually paid in full.
 
     Payments in respect of the Deposits relating to a Trust will not be subject
to the subordination provisions of the Intercreditor Agreement.
 
PAYMENTS AND DISTRIBUTIONS
 
     Payments of interest on the Deposits with respect to each Trust and
payments of principal, premium (if any) and interest on the Equipment Notes or
with respect to other Trust Property held in each Trust will be distributed by
the Paying Agent (in the case of the Deposits) or by the Trustee (in the case of
Trust Property of such Trust) to Certificateholders of such Trust on the date
receipt of such payment is confirmed, except in the case of certain types of
Special Payments. Scheduled payments of interest on the Deposits and of interest
or principal on the Equipment Notes are herein referred to as "Scheduled
Payments", and January 2 and July 2 of each year are herein referred to as
"Regular Distribution Dates". Regular Distribution Dates and Special
Distribution Dates are collectively referred to as "Distribution Dates". See
"Description of the Equipment Notes -- Principal and Interest Payments".
 
                                       34
<PAGE>   36
 
     Payments of Interest
 
     The Deposits held with respect to each Trust and the Equipment Notes held
in each Trust will accrue interest at the applicable rate per annum for
Certificates to be issued by such Trust set forth on the cover page of this
Prospectus, payable on January 2 and July 2 of each year, commencing on January
2, 1999 (or, in the case of Equipment Notes issued after such date, commencing
with the first such date to occur after initial issuance thereof). Such interest
payments will be distributed to Certificateholders of such Trust on each such
date until the final Distribution Date for such Trust, subject in the case of
payments on the Equipment Notes to the Intercreditor Agreement. Interest is
calculated on the basis of a 360-day year consisting of twelve 30-day months.
The interest rates for the Deposits and the Equipment Notes are subject to
change under certain circumstances. See "The Exchange Offer -- General".
 
     Payments of interest applicable to the Certificates issued by each of the
Trusts is supported by a Liquidity Facility provided by the Liquidity Provider
for the benefit of the holders of such Certificates in an aggregate amount
sufficient to pay interest thereon at the Stated Interest Rate for such Trust on
up to three successive Regular Distribution Dates (without regard to any future
payments of principal on such Certificates), except that the Liquidity Facility
with respect to such Trust does not cover interest payable by the Depositary on
the Deposits relating to such Trust. The Liquidity Facility for any Class of
Certificates does not provide for drawings thereunder to pay for principal of or
premium on the Certificates of such Class, any interest on the Certificates of
such Class in excess of the Stated Interest Rates, or, notwithstanding the
subordination provisions of the Intercreditor Agreement, principal of or
interest or premium on the Certificates of any other Class. Therefore, only the
holders of the Certificates to be issued by a particular Trust will be entitled
to receive and retain the proceeds of drawings under the Liquidity Facility for
such Trust. See "Description of the Liquidity Facilities".
 
     Payments of Principal
 
     Payments of principal of the Equipment Notes held in each Trust are
scheduled to be received by the Trustee on January 2 and July 2 in certain years
depending upon the terms of the Equipment Notes held in such Trust, commencing
January 2, 1999. The "Final Legal Distribution Date" for the Class A
Certificates is July 2, 2018, for the Class B Certificates is July 2, 2018 and
for the Class C Certificates is January 2, 2012.
 
     Distribution of Scheduled Payments
 
     The Paying Agent with respect to each Escrow Agreement will distribute on
each Regular Distribution Date to the Certificateholders of the Trust to which
such Escrow Agreement relates all Scheduled Payments received in respect of the
related Deposits, the receipt of which is confirmed by the Paying Agent on such
Regular Distribution Date. The Trustee of each Trust will distribute, subject to
the Intercreditor Agreement, on each Regular Distribution Date to the
Certificateholders of such Trust all Scheduled Payments received in respect of
Equipment Notes held on behalf of such Trust, the receipt of which is confirmed
by the Trustee on such Regular Distribution Date. Each Certificateholder of each
Trust will be entitled to receive a pro rata share of any distribution in
respect of Scheduled Payments of interest on the Deposits relating to such Trust
and, subject to the Intercreditor Agreement, of principal or interest on
Equipment Notes held on behalf of such Trust. Each such distribution of
Scheduled Payments will be made by the applicable Paying Agent or Trustee to the
Certificateholders of record of the relevant Trust on the Record Date applicable
to such Scheduled Payment subject to certain exceptions. (Sections 4.01, 4.02,
and Section 2.03 of the Escrow Agreement) If a Scheduled Payment is not received
by the applicable Paying Agent or Trustee on a Regular Distribution Date but is
received within five days thereafter, it will be distributed to such holders of
record on the date received. If it is received after such five-day period, it
will be treated as a Special Payment and distributed as described below.
 
                                       35
<PAGE>   37
 
     Distribution of Special Payments
 
     Any payment in respect of, or any proceeds of, any Equipment Note or the
Trust Indenture Estate under (and as defined in) each Indenture other than a
Scheduled Payment (each, a "Special Payment") will be distributed on, in the
case of an early redemption or a purchase of the Equipment Notes relating to one
or more Aircraft, the date of such early redemption or purchase (which shall be
a Business Day), and otherwise on the Business Day specified for distribution of
such Special Payment pursuant to a notice delivered by each Trustee as soon as
practicable after the Trustee has received funds for such Special Payment (each
a "Special Distribution Date"), subject to the Intercreditor Agreement. Any
unused Deposits to be distributed after the Delivery Period Termination Date or
the occurrence of a Triggering Event, together with accrued and unpaid interest
thereon and the premium payable by America West (each, also a "Special
Payment"), will be scheduled to be distributed on a date 35 days after the
Paying Agent has received notice of the event requiring such distribution (also
a "Special Distribution Date") unless such date is within ten days before or
after a Regular Distribution Date, in which case such Special Payment shall be
made on such Regular Distribution Date.
 
     Each Paying Agent, in the case of the Deposits, and each Trustee, in the
case of Trust Property or the premium payable by America West in connection with
certain distributions of unused Deposits, will mail a notice to the
Certificateholders of the applicable Trust stating the scheduled Special
Distribution Date, the related Record Date, the amount of the Special Payment
and the reason for the Special Payment. In the case of a redemption or purchase
of the Equipment Notes held in the related Trust or any distribution of unused
Deposits after the Delivery Period Termination Date or the occurrence of a
Triggering Event, such notice will be mailed not less than 20 days prior to the
date such Special Payment is scheduled to be distributed, and in the case of any
other Special Payment, such notice will be mailed as soon as practicable after
the Trustee has confirmed that it has received funds for such Special Payment.
(Section 4.02(c); Section 1.02 of the Escrow Agreement) Each distribution of a
Special Payment, other than a final distribution, on a Special Distribution Date
for any Trust will be made by the Paying Agent or the Trustee, as applicable, to
the Certificateholders of record of such Trust on the Record Date applicable to
such Special Payment. (Section 4.02(b); Section 1.02 of the Escrow Agreement)
See " -- Indenture Defaults and Certain Rights Upon an Indenture Default" and
"Description of the Equipment Notes -- Redemption".
 
     Maintenance of Accounts
 
     Each Pass Through Trust Agreement requires that the Trustee establish and
maintain, for the related Trust and for the benefit of the Certificateholders of
such Trust, one or more accounts (the "Certificate Account") for the deposit of
payments representing Scheduled Payments received by such Trustee, which shall
be one or more non-interest bearing accounts. Each Pass Through Trust Agreement
also requires that the Trustee establish and maintain, for the related Trust and
for the benefit of the Certificateholders of such Trust, one or more accounts
(the "Special Payments Account") for the deposit of payments representing
Special Payments received by such Trustee, which shall be non-interest bearing
except in certain circumstances where the Trustee may invest amounts in such
account in certain permitted investments. Pursuant to the terms of each Pass
Through Trust Agreement, the Trustee is required to deposit any Scheduled
Payments relating to the applicable Trust received by it in the Certificate
Account of such Trust and to deposit any Special Payments so received by it in
the Special Payments Account of such Trust. (Section 4.01) All amounts so
deposited will be distributed by the Trustee on a Regular Distribution Date or a
Special Distribution Date, as appropriate. (Section 4.02)
 
     Each Escrow Agreement requires that the Paying Agent establish and
maintain, for the benefit of the Receiptholders, one or more accounts (the
"Paying Agent Account"), which shall be non-interest bearing. Pursuant to the
terms of the Escrow Agreement, the Paying Agent is required to deposit interest
on Deposits relating to such Trust and any unused Deposits withdrawn by the
Escrow Agent in the Paying Agent Account. All amounts so deposited will be
distributed by the Paying Agent on a Regular Distribution Date or Special
Distribution Date, as appropriate.
 
                                       36
<PAGE>   38
 
     Final Distribution
 
     The final distribution for each Trust will be made only upon presentation
and surrender of the Certificates for such Trust at the office or agency of the
Trustee specified in the notice given by the Trustee of such final distribution.
The Trustee will mail such notice of the final distribution to the
Certificateholders of such Trust, specifying the date set for such final
distribution and the amount of such distribution. (Section 11.01) See
"-- Termination of the Trusts" below. Distributions in respect of Certificates
issued in global form will be made as described in "-- Book Entry; Delivery and
Form" below.
 
     Weekend or Holiday Distribution Date
 
     If any Regular Distribution Date or Special Distribution Date is a
Saturday, Sunday or other day on which commercial banks are authorized or
required to close in New York, New York, Phoenix, Arizona, Wilmington, Delaware,
or Hartford, Connecticut (any other day being a "Business Day"), distributions
scheduled to be made on such Regular Distribution Date or Special Distribution
Date will be made on the next succeeding Business Day without additional
interest.
 
POOL FACTORS
 
     Pool Balance
 
     The "Pool Balance" for each Trust or for the Certificates issued by any
Trust indicates, as of any date, the original aggregate face amount of the
Certificates of such Trust less the aggregate amount of all payments made in
respect of the Certificates of such Trust or in respect of Deposits relating to
such Trust other than payments made in respect of interest or premium thereon or
reimbursement of any costs and expenses in connection therewith. The Pool
Balance for each Trust or for the Certificates issued by any Trust as of any
Regular Distribution Date or Special Distribution Date will be computed after
giving effect to the payment of principal, if any, on the Equipment Notes or
other Trust Property held in such Trust and the distribution thereof to be made
on such date and the distribution of unused Deposits of such Trust to be made on
such date. (Section 1.01)
 
     Pool Factor
 
     The "Pool Factor" for each Trust as of any Regular Distribution Date or
Special Distribution Date is the quotient (rounded to the seventh decimal place)
computed by dividing the Pool Balance by the original aggregate face amount of
the Certificates of such Trust. The Pool Factor for each Trust or for the
Certificates issued by any Trust as of any Regular Distribution Date or Special
Distribution Date shall be computed after giving effect to any special
distribution with respect to unused Deposits, payment of principal of the
Equipment Notes or payment with respect to other Trust Property held in such
Trust and the distribution thereof to be made on that date. (Section 1.01) The
Pool Factor for each Trust was 1.0000000 on the Issuance Date, and will decline
as described herein to reflect reductions in the Pool Balance of such Trust. The
amount of a Certificateholder's pro rata share of the Pool Balance of a Trust
can be determined by multiplying the par value of the holder's Certificate of
such Trust by the Pool Factor for such Trust as of the applicable Regular
Distribution Date or Special Distribution Date. Notice of the Pool Factor and
the Pool Balance for each Trust will be mailed to Certificateholders of such
Trust on each Regular Distribution Date and Special Distribution Date. (Section
4.03)
 
     Aggregate Principal Amortization Schedule
 
     The following table sets forth an illustrative aggregate principal
amortization schedule for the Equipment Notes held in each Trust (the "Assumed
Amortization Schedule") and resulting Pool Factors with respect to such Trust.
The actual aggregate principal amortization schedule applicable to a Trust and
the resulting Pool Factors with respect to such Trust may differ from those set
forth below, since the amortization schedule for the Equipment Notes issued with
respect to an Aircraft may vary from such illustrative amortization schedule so
long as it complies with the Mandatory Economic Terms. In addition, the table
set forth below assumes that each Aircraft is delivered in the month scheduled
for its delivery
 
                                       37
<PAGE>   39
 
(see "Description of the Aircraft and the Appraisals -- The Appraisals" for the
delivery schedule), that Equipment Notes in the maximum principal amount in
respect of all of the Aircraft are purchased by the Trusts and that no early
redemption or purchase, or default in the payment of principal, in respect of
any Equipment Notes occurs. Actual circumstances may vary from these
assumptions, which would result in differences in the aggregate principal
amortization schedule applicable to a Trust and in the resulting Pool Factors.
 
<TABLE>
<CAPTION>
                        1998-1A TRUST                     1998-1B TRUST                     1998-1C TRUST
                       EQUIPMENT NOTES                      EQUIPMENT         1998-1B         EQUIPMENT        1998-1C
                          SCHEDULED      1998-1A TRUST   NOTES SCHEDULED       TRUST       NOTES SCHEDULED      TRUST
                         PAYMENTS OF     EXPECTED POOL     PAYMENTS OF     EXPECTED POOL     PAYMENTS OF      EXPECTED
        DATE              PRINCIPAL         FACTOR          PRINCIPAL         FACTOR          PRINCIPAL      POOL FACTOR
        ----           ---------------   -------------   ---------------   -------------   ---------------   -----------
<S>                    <C>               <C>             <C>               <C>             <C>               <C>
January 2, 1999......  $         0.00      1.0000000      $        0.00      1.0000000      $  216,502.98     0.9877716
July 2, 1999.........      552,699.82      0.9958024               0.00      1.0000000         368,788.25     0.9669420
January 2, 2000......    2,559,564.33      0.9763631         534,181.37      0.9870199       1,313,325.82     0.8927638
July 2, 2000.........    3,299,135.85      0.9513071         150,745.48      0.9833570               0.00     0.8927638
January 2, 2001......    1,407,400.00      0.9406182         567,699.58      0.9695625         310,000.00     0.8752546
July 2, 2001.........    3,405,000.00      0.9147581         437,300.42      0.9589365               0.00     0.8752546
January 2, 2002......    1,135,000.00      0.9061381         375,000.00      0.9498244         250,000.00     0.8611343
July 2, 2002.........    2,996,400.00      0.8833812         659,073.17      0.9338096               0.00     0.8611343
January 2, 2003......    1,089,600.00      0.8751059         360,000.00      0.9250620       1,034,739.47     0.8026910
July 2, 2003.........    2,633,200.00      0.8551075         870,000.00      0.9039219               0.00     0.8026910
January 2, 2004......      953,400.00      0.8478666         315,000.00      0.8962677       2,494,089.96     0.6618217
July 2, 2004.........    2,378,518.00      0.8298024         909,498.00      0.8741678               0.00     0.6618217
January 2, 2005......      908,000.00      0.8229064         300,000.00      0.8668781       1,750,706.30     0.5629397
July 2, 2005.........    2,564,378.00      0.8034306         902,244.00      0.8449545               0.00     0.5629397
January 2, 2006......      862,600.00      0.7968793         285,000.00      0.8380293       1,900,936.61     0.4555725
July 2, 2006.........    2,498,366.00      0.7779049         818,668.00      0.8181365               0.00     0.4555725
January 2, 2007......      951,741.21      0.7706767       1,060,617.00      0.7923646       1,275,529.64     0.3835290
July 2, 2007.........    2,545,424.79      0.7513448         695,872.00      0.7754556               0.00     0.3835290
January 2, 2008......    1,830,291.82      0.7374442         737,770.29      0.7575286       1,139,132.14     0.3191894
July 2, 2008.........    2,096,378.66      0.7215228         315,964.71      0.7498509               0.00     0.3191894
January 2, 2009......    2,727,243.30      0.7008100       1,116,493.47      0.7227213       1,514,243.39     0.2336631
July 2, 2009.........    1,452,341.22      0.6897799         305,872.00      0.7152889               0.00     0.2336631
January 2, 2010......    1,805,227.46      0.6760696       4,029,795.10      0.6173690       2,890,744.42     0.0703903
July 2, 2010.........    1,601,138.54      0.6639094               0.00      0.6173690       1,246,261.02     0.0000000
January 2, 2011......    4,059,262.00      0.6330803       7,756,277.01      0.4288995               0.00     0.0000000
January 2, 2012......    4,324,765.76      0.6002349       9,072,304.39      0.2084518               0.00     0.0000000
January 2, 2013......    8,169,347.26      0.5381907       7,771,113.49      0.0196217               0.00     0.0000000
January 2, 2014......   17,024,961.32      0.4088905          50,271.98      0.0184001               0.00     0.0000000
January 2, 2015......   18,273,854.60      0.2701053               0.00      0.0184001               0.00     0.0000000
January 2, 2016......   26,855,479.16      0.0661448               0.00      0.0184001               0.00     0.0000000
January 2, 2017......    8,709,280.90      0.0000000         757,238.54      0.0000000               0.00     0.0000000
</TABLE>
 
     The actual schedule of principal payments and the resulting schedule of
Pool Balances and Pool Factors may change from that set forth above if, among
other things, the aggregate principal amount of the Equipment Notes acquired by
the Trusts is less than the maximum permitted by the Mandatory Economic Terms,
Equipment Notes with respect to any Aircraft are purchased by the Trusts in
other than the month currently scheduled for delivery of such Aircraft or
Equipment Notes as to which the projected loan to Aircraft value ratios ("LTVs")
are lower than other Equipment Notes are not acquired by the Trusts.
 
     In addition, the Pool Factor and Pool Balance of each Trust will be
recomputed if there has been an early redemption, purchase, or a default in the
payment of principal or interest in respect of one or more
 
                                       38
<PAGE>   40
 
issues of the Equipment Notes held in a Trust, as described in "-- Indenture
Defaults and Certain Rights Upon an Indenture Default" and "Description of the
Equipment Notes -- Redemption", or a special distribution attributable to unused
Deposits after the Delivery Period Termination Date or the occurrence of a
Triggering Event, as described in "Description of the Deposit Agreements". In
the event of (i) any such change in the scheduled repayments or (ii) any such
redemption, purchase, default or special distribution, the Pool Factors and the
Pool Balances of each Trust so affected will be recomputed after giving effect
thereto and notice thereof will be mailed to the Certificateholders of such
Trust promptly after the Delivery Period Termination Date in the case of clause
(i) and promptly after the occurrence of any event described in clause (ii).
 
REPORTS TO CERTIFICATEHOLDERS
 
     On each Distribution Date, the applicable Paying Agent and Trustee will
include with each distribution of a Scheduled Payment or Special Payment to
Certificateholders of the related Trust a statement, giving effect to such
distribution to be made on such Distribution Date, setting forth the following
information (per $1,000 aggregate principal amount of Certificate for such
Trust, as to (2), (3), (4) and (5) below):
 
     (1) The aggregate amount of such funds distributed on such Distribution
         Date under the Pass Through Trust Agreement and the Escrow Agreement,
         indicating the amount allocable to each source.
 
     (2) The amount of such distribution under the Pass Through Trust Agreement
         allocable to principal and the amount allocable to premium (including
         any premium paid by America West with respect to unused Deposits), if
         any.
 
     (3) The amount of such distribution under the Pass Through Trust Agreement
         allocable to interest.
 
     (4) The amount of such distribution under the Escrow Agreement allocable to
         interest.
 
     (5) The amount of such distribution under the Escrow Agreement allocable to
         unused Deposits (if any).
 
     (6) The Pool Balance and the Pool Factor for such Trust. (Section 4.03)
 
     With respect to the Certificates registered in the name of DTC or its
nominee, on the Record Date prior to each Distribution Date, the applicable
Trustee will request from DTC a securities position listing setting forth the
names of all DTC Participants reflected on DTC's books as holding interests in
the Certificates on such record date. On each Distribution Date, the applicable
Paying Agent and Trustee will mail to each such DTC Participant the statement
described above and will make available additional copies as requested by such
DTC Participant for forwarding to holders of Certificates. (Section 4.03(a);
Section 2.03 of the Escrow Agreement)
 
     In addition, after the end of each calendar year, the applicable Trustee
and Paying Agent will furnish to each Certificateholder of each Trust at any
time during the preceding calendar year a report containing the sum of the
amounts determined pursuant to clauses (1), (2), (3), (4) and (5) above with
respect to the Trust for such calendar year or, in the event such person was a
Certificateholder during only a portion of such calendar year, for the
applicable portion of such calendar year, and such other items as are readily
available to such Trustee and which a Certificateholder shall reasonably request
as necessary for the purpose of such Certificateholder's preparation of its U.S.
federal income tax returns. (Section 4.03(b)) With respect to Certificates
registered in the name of DTC's nominee, such report and such other items shall
be prepared on the basis of information supplied to the applicable Trustee by
the DTC Participants and shall be delivered by such Trustee to such DTC
Participants to be available for forwarding by such DTC Participants to owners
of beneficial interests in the Certificates ("Certificate Owners") in the manner
described above. (Section 4.03(b))
 
                                       39
<PAGE>   41
 
     With respect to the Certificates issued in definitive form, the applicable
Paying Agent and Trustee will prepare and deliver the information described
above to each Certificateholder of record of each Trust as the name of such
Certificateholder appears on the records of the registrar of the Certificates.
 
INDENTURE DEFAULTS AND CERTAIN RIGHTS UPON AN INDENTURE DEFAULT
 
     A list of Indenture Defaults can be found under "Description of Equipment
Notes -- Indenture Defaults; Notice and Waiver." An Indenture Default will, with
respect to the Leased Aircraft Indentures, include an event of default under the
related Lease (a "Lease Event of Default"). Since the Equipment Notes issued
under an Indenture may be held in more than one Trust, a continuing Indenture
Default under such Indenture would affect the Equipment Notes held by each such
Trust. There are no cross-default provisions in the Indentures or in the Leases
(unless, in the case of a Lease, otherwise agreed between an Owner Participant
and America West). Consequently, events resulting in an Indenture Default under
any particular Indenture may or may not result in an Indenture Default under any
other Indenture, and a Lease Event of Default under any particular Lease may or
may not constitute a Lease Event of Default under any other Lease. If an
Indenture Default occurs in fewer than all of the Indentures, notwithstanding
the treatment of Equipment Notes issued under any Indenture under which an
Indenture Default has occurred, payments of principal and interest on the
Equipment Notes issued pursuant to Indentures with respect to which an Indenture
Default has not occurred will continue to be distributed to the holders of the
Certificates as originally scheduled, subject to the Intercreditor Agreement.
See "Description of the Intercreditor Agreement -- Priority of Distributions".
 
     Right to Cure
 
     With respect to each Leased Aircraft, the applicable Owner Trustee and
Owner Participant will, under the related Leased Aircraft Indenture, have the
right under certain circumstances to cure Indenture Defaults that result from
the occurrence of a Lease Event of Default under the related Lease. If the Owner
Trustee or the Owner Participant exercises any such cure right, the Indenture
Default will be deemed to have been cured.
 
     Resignation of Trustee In the Event of a Conflict of Interest
 
     In the event that the same institution acts as Trustee of multiple Trusts,
in the absence of instructions from the Certificateholders of any such Trust,
such Trustee could be faced with a potential conflict of interest upon an
Indenture Default. In such event, each Trustee has indicated that it would
resign as Trustee of one or all such Trusts, and a successor trustee would be
appointed in accordance with the terms of the applicable Pass Through Trust
Agreement. Wilmington Trust Company is the initial Trustee under each Trust.
 
     Consequence of Continuing Indenture Default
 
     Upon the occurrence and continuation of any Indenture Default under any
Indenture, the Controlling Party will direct the Indenture Trustee under such
Indenture in the exercise of remedies thereunder and may accelerate and sell all
(but not less than all) of the Equipment Notes issued under such Indenture to
any person, subject to certain limitations. See "Description of Intercreditor
Agreement -- Intercreditor Rights -- Sale of Equipment Notes and Aircraft". The
proceeds of such sale will be distributed pursuant to the provisions of the
Intercreditor Agreement. Any such proceeds so distributed to any Trustee upon
any such sale shall be deposited in the applicable Special Payments Account and
shall be distributed to the holders of the applicable Trust on a Special
Distribution Date. (Sections 4.01 and 4.02) The market for Equipment Notes at
the time of the existence of any Indenture Default may be very limited and there
can be no assurance as to the price at which they could be sold. If any such
Equipment Notes are sold for less than their outstanding principal amount,
certain Certificateholders will receive a smaller amount of principal
distributions than anticipated and will not have any claim for the shortfall
against America West, any Liquidity Provider, any Owner Trustee, any Owner
Participant or any Trustee.
 
                                       40
<PAGE>   42
 
     Any amount, other than Scheduled Payments received on a Regular
Distribution Date, distributed to the Trustee of any Trust by the Subordination
Agent on account of any Equipment Note or Trust Indenture Estate (as defined in
each Indenture) held in such Trust following an Indenture Default under any
Indenture will be deposited in the Special Payments Account for such Trust and
will be distributed to the Certificateholders of such Trust on a Special
Distribution Date. (Sections 4.01 and 4.02) In addition, if, following an
Indenture Default under any Leased Aircraft Indenture relating to a Leased
Aircraft, the applicable Owner Participant or Owner Trustee exercises its option
to redeem or purchase the outstanding Equipment Notes issued under such Leased
Aircraft Indenture, the price paid by such Owner Participant or Owner Trustee
for the Equipment Notes issued under such Leased Aircraft Indenture and
distributed to such Trust by the Subordination Agent will be deposited in the
Special Payments Account for such Trust and will be distributed to the
Certificateholders of such Trust on a Special Distribution Date. (Sections 4.01
and 4.02)
 
     Any funds representing payments received with respect to any defaulted
Equipment Notes, or the proceeds from the sale of any Equipment Notes, held by
the Trustee in the Special Payments Account for such Trust will, to the extent
practicable, be invested and reinvested by such Trustee in certain permitted
investments pending the distribution of such funds on a Special Distribution
Date. (Section 4.04) Such permitted investments are defined as obligations of
the United States or agencies or instrumentalities thereof for the payment of
which the full faith and credit of the United States is pledged and which mature
in not more than 60 days or such lesser time as is required for the distribution
of any such funds on a Special Distribution Date. (Section 1.01)
 
     Notice to Certificateholders of Default
 
     Each Pass Through Trust Agreement provides that the Trustee of the related
Trust will, within 90 days after the occurrence of any default, give to the
Certificateholders of such Trust notice, transmitted by mail, of all uncured or
unwaived defaults with respect to such Trust known to it, provided that, except
in the case of default in a payment of principal, premium, if any, or interest
on any of the Equipment Notes held in such Trust, the applicable Trustee will be
protected in withholding such notice if it in good faith determines that the
withholding of such notice is in the interests of such Certificateholders.
(Section 7.02) The term "default" as used in this paragraph only with respect to
any Trust means the occurrence of an Indenture Default under any Indenture
pursuant to which Equipment Notes held by such Trust were issued, as described
above, except that in determining whether any such Indenture Default has
occurred, any grace period or notice in connection therewith will be
disregarded.
 
     Trustee Entitled to Security or Indemnity
 
     Each Pass Through Trust Agreement contains a provision entitling the
Trustee of the related Trust, subject to the duty of such Trustee during a
default to act with the required standard of care, to be offered reasonable
security or indemnity by the holders of the Certificates of such Trust before
proceeding to exercise any right or power under such Pass Through Trust
Agreement at the request of such Certificateholders. (Section 7.03(e))
 
     Rights of Certificateholders
 
     Subject to certain qualifications set forth in the Pass Through Trust
Agreements and to the Intercreditor Agreement, the Certificateholders of each
Trust holding Certificates evidencing fractional undivided interests aggregating
not less than a majority in interest in such Trust shall have the right to
direct the time, method and place of conducting any proceeding for any remedy
available to the Trustee with respect to such Trust or pursuant to the terms of
the Intercreditor Agreement, or exercising any trust or power conferred on such
Trustee under such Pass Through Trust Agreement or the Intercreditor Agreement,
including any right of such Trustee as Controlling Party under the Intercreditor
Agreement or as holder of the Equipment Note. (Section 6.04)
 
                                       41
<PAGE>   43
 
     In certain cases, the holders of the Certificates of a Trust evidencing
fractional undivided interests aggregating not less than a majority in interest
of such Trust may on behalf of the holders of all the Certificates of such Trust
waive any past Indenture Default under any Indenture pursuant to which Equipment
Notes held by such Trust were issued or, if the Trustee of such Trust is the
Controlling Party, may direct the Trustee to instruct the applicable Loan
Trustee to waive any past Indenture Default and thereby annul any direction
given by such holders or Trustee to such Loan Trustee with respect thereto,
except certain defaults.
 
     Defaults That May Not Be Waived
 
     (1) A default in the deposit of any Scheduled Payment or Special Payment or
         in the distribution thereof.
 
     (2) A default in payment of the principal, premium, if any, or interest
         with respect to any of the Equipment Notes.
 
     (3) A default in respect of any covenant or provision of the related Pass
         Through Trust Agreement that cannot be modified or amended without the
         consent of each Certificateholder of such Trust affected thereby.
         (Section 6.05)
 
     Each Indenture provides that, with certain exceptions, the holders of the
majority in aggregate unpaid principal amount of the Equipment Notes issued
thereunder may on behalf of all such holders waive any past default or Indenture
Default thereunder. Notwithstanding such provisions of the Indentures, pursuant
to the Intercreditor Agreement only the Controlling Party will be entitled to
waive any such past default or Indenture Default.
 
PURCHASE RIGHTS OF CERTIFICATEHOLDERS
 
     Upon the occurrence and during the continuation of a Triggering Event, with
ten days' written notice to the Trustee and each Certificateholder of the same
Class, Certificateholders of a junior class will have the right to purchase
Certificates ranking in senior priority. Consequently, the Class B
Certificateholders will have the right to purchase all, but not less than all,
of the Class A Certificates and the Class C Certificateholders will have the
right to purchase all, but not less than all, of the Class A Certificates and
the Class B Certificates. Additionally, if the Class D Certificates are issued,
the Class D Certificateholders will have the right to purchase all, but not less
than all, of the Class A Certificates, the Class B Certificates and the Class C
Certificates. In each such case, the purchase price of Certificates will equal
the Pool Balance of the relevant Class or Classes of Certificates plus accrued
and unpaid interest thereon to the date of purchase without premium but
including any other amounts due to the Certificateholders of such Class or
Classes. In each case, if prior to the end of the ten-day period, any other
Certificateholder of the same Class notifies the purchasing Certificateholder
that the other Certificateholder wants to participate in such purchase, then
such other Certificateholder may join with the purchasing Certificateholder to
purchase the Certificates pro rata based on the interest in the Trust held by
each Certificateholder. (Section 6.01(b))
 
PTC EVENT OF DEFAULT
 
     A "PTC Event of Default" is defined under each Pass Through Trust Agreement
as the failure to pay within ten Business Days of the due date thereof either
the outstanding Pool Balance of the applicable Class of Certificates on the
Final Legal Distribution Date for such Class or the interest due on such Class
of Certificates on any Distribution Date (unless, in the case of the Class A, B,
or C Certificates, the Subordination Agent shall have made Interest Drawings, or
a withdrawal from the Cash Collateral Account for such Class of Certificates,
with respect thereto in an aggregate amount sufficient to pay such interest and
shall have distributed such amount to the Trustee entitled thereto). Any failure
to make expected principal distributions on any Class of Certificates on any
Regular Distribution Date (other than the Final Maturity Date) will not
constitute a PTC Event of Default with respect to such Certificates. A
 
                                       42
<PAGE>   44
 
PTC Event of Default with respect to the most senior outstanding Class of
Certificates resulting from an Indenture Default under all Indentures will
constitute a Triggering Event.
 
MERGER, CONSOLIDATION AND TRANSFER OF ASSETS
 
     America West is prohibited from consolidating with or merging into any
other corporation or transferring substantially all of its assets as an entirety
to any other corporation unless it meets all the requirements noted below.
 
     Requirements for Consolidation, Merger or Transfer of Assets
 
     (1) The surviving successor or transferee corporation shall be a "citizen
         of the United States" as defined in Title 49 of the United States Code,
         as amended, relating to aviation (the "Transportation Code").
 
     (2) The surviving successor or transferee corporation shall be a United
         States certificated air carrier.
 
     (3) The surviving successor or transferee corporation shall expressly
         assume all of the obligations of America West contained in the Pass
         Through Trust Agreements, the Note Purchase Agreement, the Indentures,
         the Participation Agreements and the Leases.
 
     (4) America West shall have delivered a certificate indicating that such
         transaction complies with such conditions. (Section 5.02)
 
     (5) Additionally, after giving effect to such transaction, no Lease Event
         of Default, in the case of a Leased Aircraft, or Indenture Event of
         Default, in the case of an Owned Aircraft, shall have occurred and be
         continuing. (Leases, Section 13.2; Owned Aircraft Indenture, Section
         4.07)
 
     The Pass Through Trust Agreements, the Note Purchase Agreement, the
Indentures, the Participation Agreements and the Leases do not contain any
covenants or provisions which may afford the applicable Trustee or
Certificateholders protection in the event of a highly leveraged transaction,
including transactions effected by management or affiliates, which may or may
not result in a change in control of America West.
 
MODIFICATIONS OF THE PASS THROUGH TRUST AGREEMENTS AND CERTAIN OTHER AGREEMENTS
 
     Each Pass Through Trust Agreement contains provisions permitting, at the
request of the Company, the execution of amendments or supplements to such Pass
Through Trust Agreement or, if applicable, to the Deposit Agreements, the Escrow
Agreements, the Intercreditor Agreement, the Note Purchase Agreement, the
Registration Rights Agreement or any Liquidity Facility, without the consent of
the holders of any of the Certificates of such Trust for certain reasons set
forth below.
 
     Basis for Amendments or Supplements to Pass Through Trust Agreements
 
     (1) To evidence the succession of another corporation to America West and
         the assumption by such corporation of America West's covenants
         contained in such Pass Through Trust Agreement, and its obligations
         under the Note Purchase Agreement, the Registration Rights Agreement or
         any Liquidity Facility.
 
     (2) To add to the covenants of America West for the benefit of holders of
         such Certificates or to surrender any right or power conferred upon
         America West in such Pass Through Trust Agreement, the Note Purchase
         Agreement, the Registration Rights Agreement or any Liquidity Facility.
 
     (3) To correct or supplement any provision of such Pass Through Trust
         Agreement, the Deposit Agreements, the Escrow Agreements, the
         Intercreditor Agreement, the Note Purchase Agreement, the Registration
         Rights Agreement or any Liquidity Facility which may be defective or
         inconsistent with any other provision in such Pass Through Trust
         Agreement, the Deposit
 
                                       43
<PAGE>   45
 
         Agreements, the Escrow Agreements, the Intercreditor Agreement, the
         Note Purchase Agreement, the Registration Rights Agreement or any
         Liquidity Facility, as applicable, or to cure any ambiguity, correct
         any mistake or to modify any other provisions with respect to matters
         or questions arising under such Pass Through Trust Agreement, the
         Deposit Agreements, the Escrow Agreements, the Intercreditor Agreement,
         the Note Purchase Agreement, the Registration Rights Agreement or any
         Liquidity Facility, provided such action shall not materially adversely
         affect the interests of the holders of such Certificates.
 
     (4) To comply with any requirement of the SEC, any applicable law, rules or
         regulations of any exchange or quotation system on which the
         Certificates are listed, any regulatory body or the Registration Rights
         Agreement to effectuate the Exchange Offer.
 
     (5) To modify, eliminate or add to the provision of such Pass Through Trust
         Agreement to the extent necessary to continue qualification thereof
         under the Trust Indenture Act and to add to such Pass Through Trust
         Agreement such other provisions as may be expressly permitted by the
         Trust Indenture Act.
 
     (6) To provide for a successor Trustee or to add to or change any provision
         of such Pass Through Trust Agreement as shall be necessary to
         facilitate the administration of the Trust thereunder by more than one
         Trustee.
 
     (7) To provide certain information required under such Pass Through Trust
         Agreement as to the Trustee.
 
     (8) To modify or eliminate provisions relating to the transfer or exchange
         of Exchange Certificates or the Initial Certificates upon consummation
         of the Exchange Offer (as defined in the Registration Rights Agreement)
         or effectiveness of the Shelf Registration Statement or the Exchange
         Offer Registration Statement.
 
Any such amendment or supplement listed above may be made only if it does not
adversely affect the status of the Trust as a grantor trust under Subpart E,
Part I of Subchapter J of Chapter 1 of Subtitle A of the Code for U.S. federal
income tax purposes. (Section 9.01)
 
     Each Pass Through Trust Agreement also contains provisions permitting the
execution, with the consent of the holders of the Certificates of the related
Trust evidencing fractional undivided interests aggregating not less than a
majority in interest of such Trust, and with the consent of the applicable Owner
Trustee (such consent not to be unreasonably withheld), of amendments or
supplements for the purposes of adding any provisions to or changing or
eliminating any of the provisions of such Pass Through Trust Agreement, the
Deposit Agreements, the Escrow Agreements, the Intercreditor Agreement, the Note
Purchase Agreement, the Registration Rights Agreement or any Liquidity Facility
or of modifying the rights and obligations of the Certificateholders, except
that no such amendment or supplement may, without the consent of the holder of
each Certificate so affected thereby, have any of the effects set forth below.
 
     Amendments or Supplements That Require Consent of the Affected Holder
 
     (1) Reduce in any manner the amount of, or delay the timing of, any receipt
         by the Trustee (or, with respect to the Deposits, the
         Certificateholders) of payments with respect to the Deposits, the
         Equipment Notes or other Trust Property held in such Trust or
         distributions in respect of any Certificate related to such Trust, or
         change the date or place of any payment in respect of any Certificate,
         or make distributions payable in coin or currency other than that
         provided for in such Certificates, or impair the right of any
         Certificateholder of such Trust to institute suit for the enforcement
         of any such payment when due.
 
     (2) Permit the disposition of any Equipment Note held in such Trust, except
         as provided in such Pass Through Trust Agreement, or otherwise deprive
         any Certificateholder of the benefit of the ownership of the applicable
         Equipment Notes.
 
                                       44
<PAGE>   46
 
     (3) Alter the priority of distributions specified in the Intercreditor
         Agreement in a manner adverse to the Certificateholders.
 
     (4) Reduce the percentage of the aggregate fractional undivided interests
         of the Trust provided for in such Pass Through Trust Agreement, the
         consent of the holders of which is required for any such supplemental
         trust agreement or for any waiver provided for in such Pass Through
         Trust Agreement.
 
     (5) Modify any of the provisions relating to the rights of the
         Certificateholders in respect of the waiver of events of default or
         receipt of payment.
 
     (6) Adversely affect the status of the Trust as a grantor trust under
         Subpart E, Part I of Subchapter J of Chapter 1 of Subtitle A of the
         Code for U.S. federal income tax purposes. (Section 9.02)
 
     Actions by Trustee Upon Receipt of Consent to Amend or Supplement any
Agreement
 
     In the event that a Trustee, as holder (or beneficial owner through the
Subordination Agent) of any Equipment Note in trust for the benefit of the
Certificateholders of the relevant Trust or as Controlling Party under the
Intercreditor Agreement, receives (directly or indirectly through the
Subordination Agent) a request for a consent to any amendment, modification,
waiver or supplement under any Indenture, any Participation Agreement, any
Lease, any Equipment Note or any other related document, the Trustee shall
forthwith send a notice of such proposed amendment, modification, waiver or
supplement to each Certificateholder of the relevant Trust as of the date of
such notice. Such notice shall request direction from the Certificateholders
regarding certain matters, as set forth below.
 
     Information Requested by Trustee from Certificateholders
 
     (1) Whether or not to take or refrain from taking (or direct the
         Subordination Agent to take or refrain from taking) any action which a
         holder of such Equipment Note or the Controlling Party has the option
         to take.
 
     (2) Whether or not to give or execute (or direct the Subordination Agent to
         give or execute) any waivers, consents, amendments, modifications or
         supplements as a holder of such Equipment Note or as Controlling Party.
 
     (3) How to vote (or direct the Subordination Agent to vote) any Equipment
         Note if a vote has been called for with respect thereto.
 
     Provided such a request for Certificateholder direction shall have been
made, in directing any action or casting any vote or giving any consent as the
holder of any Equipment Note (or in directing the Subordination Agent in any of
the foregoing), the Trustee shall act as follows: (1) if the Trustee is acting
in a capacity other than as Controlling Party, the Trustee shall vote for or
give consent to any such action with respect to such Equipment Note in the same
proportion as that of (x) the aggregate face amounts of all Certificates
actually voted in favor of or for giving consent to such action by such
direction of Certificateholders to (y) the aggregate face amount of all
outstanding Certificates of the relevant Trust; and (2) if the Trustee is acting
in its capacity as the Controlling Party, the Trustee shall vote as directed in
such Certificateholder direction by the Certificateholders evidencing fractional
undivided interests aggregating not less than a majority in interest in the
relevant Trust. For purposes of the immediately preceding sentence, a
Certificate shall have been "actually voted" if the Holder of such Certificate
has delivered to the Trustee an instrument evidencing such Holder's consent to
such direction prior to two Business Days before the Trustee directs such action
or casts such vote or gives such consent. Notwithstanding the foregoing, but
subject to certain rights of the Certificateholders under the relevant Pass
Through Trust Agreement and subject to the Intercreditor Agreement, the Trustee
may, in its own discretion and at its own direction, consent and notify the
relevant Loan Trustee of such consent (or direct the Subordination Agent to
consent and notify the relevant Loan Trustee of such consent) to any amendment,
modification, waiver or supplement under the relevant Indenture, Participation
Agreement or Lease, any relevant Equipment Note or any other related document,
if an Indenture Default under any
 
                                       45
<PAGE>   47
 
Indenture shall have occurred and be continuing, or if such amendment,
modification, waiver or supplement will not materially adversely affect the
interests of the Certificateholders. (Section 10.01)
 
OBLIGATION TO PURCHASE EQUIPMENT NOTES
 
     The Trustees are obligated to purchase the Equipment Notes issued with
respect to the Aircraft during the Delivery Period, subject to the terms and
conditions of the Note Purchase Agreement. Under the Note Purchase Agreement,
America West agrees to finance each Aircraft in the manner provided therein and
in connection therewith will have the option of entering into a leverage lease
financing or a secured debt financing with respect to each Aircraft. The Note
Purchase Agreement provides for the relevant parties to enter into, with respect
to each Leased Aircraft, a participation agreement, a Lease and a Leased
Aircraft Indenture relating to the financing of such Leased Aircraft. The Note
Purchase Agreement also provides for the relevant parties to enter into, with
respect to each Owned Aircraft, a participation agreement (any such
participation agreement, whether for a Leased Aircraft or an Owned Aircraft,
being herein referred to as a "Participation Agreement") and an Owned Aircraft
Indenture relating to the financing of such Owned Aircraft. The description of
such agreements in this Prospectus is based on the forms of such agreements
contemplated by the Note Purchase Agreement. The terms of the agreements
actually entered into may differ from the forms of such agreements and,
consequently, may differ from the description of such agreements contained in
this Prospectus. See "Risk Factors -- Risk Factors Relating to the Certificates
and the Offering -- Owner Participant; Series D Certificateholders; Revisions to
Agreements".
 
     Under the Note Purchase Agreement, the terms of such agreements are
required to contain the Mandatory Document Terms and not vary the Mandatory
Economic Terms. In addition, America West is obligated to certify to the
Trustees that any such modifications do not materially and adversely affect the
Certificateholders and to obtain written confirmation from each Rating Agency
that the use of versions of such agreements modified in any material respect
will not result in a withdrawal, suspension or downgrading of the rating of any
Class of Certificates. Further, under the Note Purchase Agreement, it is a
condition precedent to the obligation of each Trustee to purchase the Equipment
Notes related to the financing of an Aircraft that no Triggering Event shall
have occurred. The Trustees will have no right or obligation to purchase
Equipment Notes after the Delivery Period Termination Date. The "Mandatory
Economic Terms", as defined in the Note Purchase Agreement, require, among other
things, compliance with the items noted below.
 
     Requirements of the Mandatory Economic Terms
 
      (1) The maximum principal amount of all the Equipment Notes issued with
          respect to an Aircraft not exceed the maximum principal amount of
          Equipment Notes indicated for each such Aircraft as set forth in
          "Description of the Equipment Notes -- Equipment Notes and the
          Aircraft" under the column "Maximum Principal Amount of Equipment
          Notes".
 
      (2) The average life per aircraft of the Series A Equipment Notes shall
          not be less than 9.0 years or extend beyond 13.5 years, of the Series
          B Equipment Notes shall not be less than 8.0 years or extend beyond
          12.7 years, and of the Series C Equipment Notes shall not be less than
          4.0 years or extend beyond 8.5 years, in each case from the Issuance
          Date.
 
      (3) As of the first Regular Distribution Date following the delivery of
          the last Aircraft to be delivered, the average life of the Class A
          Certificates, the Class B Certificates and the Class C Certificates
          shall not be less than, respectively, 11.0 years, 10.0 years and 6.0
          years nor shall extend beyond, respectively, 12.9 years, 11.4 years
          and 7.5 years from the Issuance Date.
 
      (4) The loan to aircraft value ratio at the time of issuance of the
          Equipment Notes and on any Regular Distribution Date thereafter shall
          not exceed 43% in the case of the Series A Equipment Notes, 57% in the
          case of the Series B Equipment Notes and 71% in the case of the Series
          C Equipment Notes (in each case computed on the basis of an assumed
          value of such
 
                                       46
<PAGE>   48
 
          Aircraft no greater than the value for such Aircraft set forth under
          "Description of the Equipment Notes -- Equipment Notes and the
          Aircraft" under the column "Appraised Value" and the Depreciation
          Assumption defined under "Description of the Equipment Notes -- Loan
          to Value Ratios of Equipment Notes").
 
      (5) The final maturity date of the Series A Equipment Notes not be
          extended beyond January 2, 2017, the Series B Equipment Notes not be
          extended beyond January 2, 2017 and the Series C Equipment Notes not
          be extended beyond July 2, 2010.
 
      (6) The original aggregate principal amount of all of the Equipment Notes
          of each Series shall not exceed the original aggregate face amount of
          the Certificates issued by the corresponding Trust.
 
      (7) The interest rate applicable to each Series of Equipment Notes must be
          equal to the rate applicable to the Certificates issued by the
          corresponding Trust.
 
      (8) The payment dates for the Equipment Notes and basic rent under the
          Leases must be January 2 and July 2.
 
      (9) Basic rent, stipulated loss values, early buy-out amount and
          termination values under the Leases must be sufficient to pay amounts
          due with respect to the related Equipment Notes.
 
     (10) The amounts payable under the all-risk aircraft hull insurance
          maintained with respect to each Aircraft must be sufficient to pay the
          applicable stipulated loss value, subject to certain rights of
          self-insurance.
 
     (11) The following shall be provided as set forth in the form of
          Participation Agreements, Lease and Indentures (collectively, the
          "Aircraft Operative Agreements"):
 
         (a) The past due rate in the Indentures and the Leases.
 
         (b) The Make-Whole Premium payable under the Indentures.
 
         (c) The provisions relating to the redemption and purchase of Equipment
             Notes in the Indentures.
 
         (d) The minimum liability insurance amount on Aircraft in the Leases.
 
         (e) The interest rate payable with respect to stipulated loss value in
the Leases.
 
         (f) The indemnification of the Loan Trustees, Subordination Agent,
             Liquidity Provider, Trustees and Escrow Agents with respect to
             certain taxes and expenses.
 
     The "Mandatory Document Terms" prohibit modifications in any material
adverse respect to certain specified provisions of the Aircraft Operative
Agreements contemplated by the Note Purchase Agreement.
 
     Prohibited Modifications Under the Mandatory Document Terms
 
     (1) In the case of the Indentures, the following modifications are
         prohibited:
 
        (a) To the Granting Clause of the Indentures so as to deprive the Note
            Holders of a security interest in the Aircraft, certain of America
            West's rights under its purchase agreement with the Aircraft
            manufacturer and, in the case of a Leased Aircraft, the Lease or to
            eliminate any of the "Secured Obligations" as defined therein.
 
        (b) To certain provisions relating to the issuance, redemption,
            purchase, payments, and ranking of the Equipment Notes (including
            the obligation to pay the Make-Whole Premium in certain
            circumstances).
 
        (c) To certain provisions regarding Indenture Defaults, remedies
            relating thereto and rights of the Owner Trustee and Owner
            Participant in such circumstances.
 
        (d) To certain provisions relating to any replaced airframe or engines
            with respect to an Aircraft.
 
                                       47
<PAGE>   49
 
         (e) To the provision that New York law will govern the Indentures.
 
     (2) In the case of the Leases, modifications are prohibited to certain
         provisions regarding the obligations of America West, including:
 
         (a) To pay basic rent, stipulated loss value, early buy-out amount and
             termination value to the Leased Aircraft Trustee.
 
         (b) To record the Leased Aircraft Indenture with the Federal Aviation
             Administration and to maintain such Indenture as a first-priority
             perfected mortgage on the related Aircraft.
 
         (c) To furnish certain opinions with respect to a replacement airframe.
 
         (d) To consent to the assignment of the Lease by the Owner Trustee as
             collateral under the Leased Aircraft Indenture, as well as
             modifications which would either alter the provision that New York
             law will govern the Lease or would deprive the Loan Trustee of
             rights expressly granted to it under the Leases.
 
     (3) In the case of the Participation Agreements, the following
         modifications are prohibited:
 
         (a) To certain conditions to the obligations of the Trustees to
             purchase the Equipment Notes issued with respect to an Aircraft
             involving good title to such Aircraft, obtaining a certificate of
             airworthiness with respect to such Aircraft, entitlement to the
             benefits of Section 1110 with respect to such Aircraft and filings
             of certain documents with the Federal Aviation Administration.
 
         (b) To the provisions restricting the Note Holder's ability to transfer
             such Equipment Notes.
 
         (c) To certain provisions so as to deprive the Note Holders of a first
             priority security interest in the Aircraft.
 
         (d) To certain provisions requiring the delivery of legal opinions.
 
         (e) To the provision that New York law will govern the Participation
Agreements.
 
     In the case of all of the Aircraft Operative Agreements, modifications are
prohibited in any material adverse respect as regards the interest of the Note
Holders, the Subordination Agent, the Liquidity Provider or the Loan Trustee in
the definition of "Make-Whole Premium". Notwithstanding the foregoing, any such
Mandatory Document Term may be modified to correct or supplement any such
provision which may be defective or to cure any ambiguity or correct any
mistake, provided that any such action shall not materially adversely affect the
interests of the Note Holders, the Subordination Agent, the Liquidity Provider,
the Loan Trustee or the Certificateholders.
 
POSSIBLE ISSUANCE OF CLASS D CERTIFICATES
 
     America West may elect to issue Series D Equipment Notes, which will be
funded from sources other than this Offering. America West may elect to fund the
sale of the Series D Equipment Notes through the sale of Class D Certificates.
America West will not issue any Series D Equipment Notes at any time prior to
the consummation of this Offering. The Note Purchase Agreement provides that
America West's ability to issue any Series D Equipment Notes is contingent upon
its obtaining written confirmation from each Rating Agency that the issuance of
such Series D Equipment Notes will not result in a withdrawal or downgrading of
the rating of any Class of Certificates. If the Class D Certificates are issued,
the Trustee with respect to such Certificates will become a party to the
Intercreditor Agreement. See "Description of the Intercreditor Agreement".
 
LIQUIDATION OF ORIGINAL TRUSTS
 
     At the Transfer Date, each of the Original Trusts will transfer and assign
all of its assets and rights to a Successor Trust with substantially identical
terms, except that the Successor Trusts will not have the right to purchase new
Equipment Notes and Delaware law governs the Original Trusts and New York
                                       48
<PAGE>   50
 
law will govern the Successor Trusts. The Trustee of each of the Original Trusts
will also act as Trustee of the corresponding Successor Trust, and each
Successor Trustee will assume the obligations of the Original Trustee under each
transaction document to which such Original Trustee was a party. Upon
effectiveness of such transfer, assignment and assumption, each of the Original
Trusts will be liquidated and each of the Certificates will represent the same
interest in the Successor Trust as it represented in the Original Trust
immediately prior to such transfer and assignment. Unless the context otherwise
requires, all references in this Prospectus to the Trusts, the Trustees, the
Pass Through Trust Agreements and similar terms shall be applicable with respect
to the Original Trusts until the effectiveness of such transfer, assignment and
assumption and thereafter shall be applicable with respect to the Successor
Trusts. If for any reason such transfer, assignment and assumption cannot be
effected to any Successor Trust, the related Original Trust will continue in
existence until it is effected.
 
TERMINATION OF THE TRUSTS
 
     The obligations of America West and the applicable Trustee with respect to
a Trust will terminate upon the distribution to Certificateholders of such Trust
of all amounts required to be distributed to them pursuant to the applicable
Pass Through Trust Agreement and the disposition of all property held in such
Trust. The applicable Trustee will send to each Certificateholder of such Trust
notice of the termination of such Trust, the amount of the proposed final
payment and the proposed date for the distribution of such final payment for
such Trust. The final distribution to any Certificateholder of such Trust will
be made only upon surrender of such Certificateholder's Certificates at the
office or agency of the applicable Trustee specified in such notice of
termination. (Section 11.01)
 
THE TRUSTEES
 
     The Trustee for each Trust is Wilmington Trust Company.
 
     With certain exceptions, the Trustees make no representations as to the
validity or sufficiency of the Pass Through Trust Agreements, the Certificates,
the Intercreditor Agreement, the Equipment Notes, the Deposit Agreements, the
Escrow Agreements, the Indentures, the Participation Agreements, the Leases or
other related documents. (Sections 7.04 and 7.15) The Trustee of any Trust shall
not be liable, with respect to the Certificates of such Trust, for any action
taken or omitted to be taken by it in good faith in accordance with the
direction of the holders of Certificates of such Trust evidencing fractional
undivided interests aggregating not less than a majority in interest of such
Trust. Subject to certain provisions, the Trustees shall be under no obligation
to exercise any of their rights or powers under any Pass Through Trust Agreement
at the request of any holders of Certificates issued thereunder unless there
shall have been offered to the Trustees reasonable security and Indemnity.
(Section 7.03(e)) Each Pass Through Trust Agreement provides that the Trustees
in their individual or any other capacity may acquire and hold Certificates
issued thereunder and, subject to certain conditions, may otherwise deal with
America West, with any Owner Trustee or with any Loan Trustee with the same
rights they would have if they were not the Trustees. (Section 7.05)
 
     Any Trustee may resign with respect to any or all of the Trusts of which it
is the Trustee at any time, in which event America West will be obligated to
appoint a successor trustee. If any Trustee ceases to be eligible to continue as
Trustee with respect to a Trust or becomes incapable of acting as Trustee or
becomes insolvent, America West may remove such Trustee, or any holder of the
Certificates of such Trust for at least six months may, on behalf of such holder
and all others similarly situated, petition any court of competent jurisdiction
for the removal of such Trustee and the appointment of a successor trustee. Any
resignation or removal of the Trustee with respect to a Trust and appointment of
a successor trustee for such Trust does not become effective until acceptance of
the appointment by the successor trustee. (Sections 7.09 and 7.10) Pursuant to
such resignation and successor trustee provisions, it is possible that a
different trustee could be appointed to act as the successor trustee with
respect to each Trust. All references in this Prospectus to the Trustee should
be read to take into account the possibility that the Trusts could have
different successor trustees in the event of such a resignation or removal.
 
                                       49
<PAGE>   51
 
     Each Pass Through Trust Agreement provides that America West will pay or
cause to be paid the applicable Trustee's fees and expenses. (Section 7.07)
 
BOOK-ENTRY; DELIVERY AND FORM
 
     The New Certificates of each Trust will be represented by one or more
permanent global Certificates, in definitive, fully registered form without
interest coupons (the "Global Certificates"), to be deposited with the Trustee
as custodian for The Depository Trust Company ("DTC") and registered in the name
DTC or its nominee.
 
     The Depository Trust Company
 
     DTC has advised America West as follows: DTC is a limited purpose trust
company organized under the laws of the State of New York, a "banking
organization" within the meaning of the New York Banking law, a member of the
Federal Reserve System, a "clearing corporation" within the meaning of the
Uniform Commercial Code and a "Clearing Agency" registered pursuant to the
provisions of Section 17A of the Exchange Act. DTC was created to hold
securities for its participants and facilitate the clearance and settlement of
securities transactions between participants through electronic book-entry
changes in accounts of its participants, thereby eliminating the need for
physical movement of certificates. Participants include securities brokers and
dealers, banks, trust companies and clearing corporations and certain other
organizations. Indirect access to the DTC system is available to others such as
banks, brokers, dealers and trust companies that clear through or maintain a
custodial relationship with a participant, either directly or indirectly
("Indirect Participants").
 
     Neither America West nor the Trustee has any responsibility for the
performance by DTC or its participants or indirect participants of their
respective obligations under the rules and procedures governing their
operations.
 
     If DTC is at any time unwilling or unable to continue as a depositary for
the Global Certificates and a successor depositary is not appointed by within 90
days, the Trusts will issue certificates in definitive, fully registered form in
exchange for the Global Certificates.
 
     Ownership of Global Certificates
 
     Ownership of beneficial interests in Global Certificates is limited to
persons who have accounts with DTC ("DTC Participants") or persons who hold
interests through DTC Participants. Ownership of beneficial interests in the
Global Certificates is shown on, and the transfer of that ownership is effected
only through, records maintained by DTC or its nominee (with respect to
interests of DTC Participants) and the records of DTC Participants (with respect
to interests of persons other than participants). The laws of some states
require that certain purchasers of securities take physical delivery of such
securities. Such limits and such laws may limit the market for beneficial
interests in the Global Certificates.
 
     So long as DTC or its nominee is the registered owner or holder of the
Global Certificates, DTC or such nominee, as the case may be, will be considered
the sole record owner or holder of the Certificates represented by such Global
Certificates for all purposes under the related Pass Through Trust Agreements.
No beneficial owners of an interest in the Global Certificates will be able to
transfer that interest except in accordance with DTC's applicable procedures, in
addition to those provided for under the Pass Through Trust Agreements and, if
applicable, the Euroclear System or Cedel Bank Societe Anonyme.
 
     Payments of Principal and Interest on the Global Certificates
 
     Payments of the principal of, premium, if any, and interest on the Global
Certificates will be made to DTC or its nominee, as the case may be, as the
registered owner thereof. Neither America West, the Trustee, nor any paying
agent will have any responsibility or liability for any aspect of the records
relating to or payments made on account of beneficial ownership interests in the
Global Certificates or for maintaining, supervising or reviewing any records
relating to such beneficial ownership interests.
 
                                       50
<PAGE>   52
 
     America West expects that DTC or its nominee, upon receipt of any payment
of principal, premium, if any, or interest in respect of the Global Certificates
will credit DTC Participants' accounts with payments in amounts proportionate to
their respective beneficial ownership interests in the principal amount of such
Global Certificates, as shown on the records of DTC or its nominee. America West
also expects that payments by participants to owners of beneficial interests in
such Global Certificates held through such participants will be governed by
standing instructions and customary practices, as is now the case with
securities held for the accounts of customers registered in the names of
nominees for such customers. Such payments will be the responsibility of such
participants.
 
                     DESCRIPTION OF THE DEPOSIT AGREEMENTS
 
     The following summary describes certain terms of the Deposit Agreements.
The summary does not purport to be complete and is qualified in its entirety by
reference to all of the provisions of the Deposit Agreements, which have been
filed as exhibits to the Registration Statement. The provisions of the Deposit
Agreements are substantially identical except as otherwise indicated. Upon
request, copies of such documents will be furnished to any holder of the
Certificates. Requests for such documents should be addressed to the Trustees.
 
GENERAL
 
     Under the Escrow Agreements, the Escrow Agent with respect to each Trust
has entered into a separate Deposit Agreement with the Depositary pursuant to
which the Depositary has established separate accounts into which the proceeds
of the initial sale of the Old Certificates of such Trust were deposited on
behalf of such Escrow Agent, from which the Escrow Agent, upon request from the
Trustee of such Trust, will make withdrawals and into which such Trustee will
make re-deposits during the Delivery Period. Pursuant to the Deposit Agreement
with respect to each Trust, on each Regular Distribution Date the Depositary
will pay to the Paying Agent on behalf of the applicable Escrow Agent, for
distribution to the Certificateholders of such Trust, an amount equal to
interest accrued on the Deposits relating to such Trust during the relevant
interest period at a rate per annum equal to the interest rate applicable to the
Certificates issued by such Trust.
 
     The interest rates payable on the Deposits are subject to change under
certain circumstances described in "The Exchange Offer -- General". Upon each
delivery of an Aircraft during the Delivery Period, the Trustees for the Class A
Trust, the Class B Trust and the Class C Trust will request the Escrow Agent
relating to such Trust to withdraw from the applicable Deposits funds sufficient
to enable the Trustee of such Trust to purchase the Equipment Note of the series
applicable to such Trust issued with respect to such Aircraft. Accrued but
unpaid interest on all such Deposits withdrawn will be paid on the next Regular
Distribution Date. Any portion of any Deposit withdrawn which is not used to
purchase such Equipment Note will be re-deposited by each Trustee into an
account relating to the applicable Trust. The Deposits relating to each Trust
and interest paid thereon are not subject to the subordination provisions of the
Intercreditor Agreement and will not be available to pay any other amount in
respect to the Certificates.
 
UNUSED DEPOSITS
 
     The Trustees' obligations to purchase the Equipment Notes issued with
respect to each Aircraft are subject to satisfaction of certain conditions at
the time of delivery, as set forth in the Note Purchase Agreement. See
"Description of the New Certificates -- Obligation to Purchase Equipment Notes".
Since the Aircraft are scheduled for delivery from time to time during the
Delivery Period, no assurance can be given that all such conditions will be
satisfied at the time of delivery for each Aircraft. Moreover, since the
Aircraft will be newly or recently manufactured, their delivery as scheduled is
subject to delays in the manufacturing process and to the manufacturer's right
to postpone deliveries under its agreement with America West. See "Description
of the Aircraft and Appraisals -- Deliveries of Aircraft".
 
                                       51
<PAGE>   53
 
     Depending on the circumstances of the financing of each Aircraft, the
maximum aggregate principal amount of Equipment Notes may not be issued. In
addition, if any funds remain as Deposits with respect to any Trust at the
Delivery Period Termination Date, they will be withdrawn by the Escrow Agent and
distributed, with accrued and unpaid interest thereon to the Certificateholders
of such Trust after at least 15 days' prior written notice. In addition, such
distribution will include a premium payable by America West equal to the Deposit
Make-Whole Premium with respect to the remaining Deposits applicable to each
Trust, except that with respect to the Class C Trust, the Deposit Make-Whole
Premium in respect of the remaining Deposits applicable to such Trust will be
payable only to the extent such remaining Deposits exceed the $5,000,000 (the
"Par Redemption Amount").
 
     Since the maximum principal amount of Equipment Notes may not be issued
with respect to an Aircraft and, in each such case, the Series C Equipment Notes
are more likely not to be issued in the maximum principal amount as compared to
the other Equipment Notes, it is more likely that a distribution of unused
Deposits will be made with respect to the Class C Certificates as compared to
the other Certificates. In addition, notwithstanding the Par Redemption Amount
limitation, if any Aircraft is not delivered by the manufacturer on or prior to
the Delivery Period Termination Date due to any reason not occasioned by America
West's fault or negligence and no Substitute Aircraft is provided in lieu of
such Aircraft, no Deposit Make-Whole Premium will be paid with respect to the
unused Deposits to be distributed as a result of such failure to deliver in an
amount (the "Non-Premium Amount") equal to the maximum principal amount of
Equipment Notes that could have been issued and acquired by such Trust with
respect to such Aircraft in accordance with the Mandatory Economic Terms and
such unused Deposits shall not be included in the calculation of the Par
Redemption Amount.
 
     "Deposit Make-Whole Premium" means, with respect to the distribution of
unused Deposits to holders of any Class of Certificates, as of any date of
determination, an amount, if any, determined pursuant to the following formula
(any negative amount being deemed equal to zero):
 
     Formula for Deposit Make-Whole Premium
 
     (1) The present value of the excess of
 
         (a) the scheduled payment of principal and interest to maturity of the
             Equipment Notes, assuming the maximum principal amount thereof (the
             "Maximum Amount") minus any Non-Premium Amount and, in the case of
             Class C Certificates only, the Par Redemption Amount (without
             duplication) were issued, on each remaining Regular Distribution
             Date for such Class under the Assumed Amortization Schedule, over
 
         (b) the scheduled payment of principal and interest to maturity of the
             Equipment Notes actually acquired by the Trustee for such Class on
             each such Regular Distribution Date, such present value computed by
             discounting such excess on a semiannual basis on each Regular
             Distribution Date (assuming a 360-day year of twelve 30-day months)
             using a discount rate equal to the Treasury Yield plus 225 basis
             points in the case of the Class A Certificates, 250 basis points in
             the case of the Class B Certificates and 325 basis points in the
             case of the Class C Certificates, over
 
     (2) the amount of such unused Deposits to be distributed to the holders of
         such Certificates, minus any Non-Premium Amount and, in the case of
         Class C Certificates only, the Par Redemption Amount (without
         duplication), plus accrued and unpaid interest on such net amount to
         but excluding the date of determination from and including the
         preceding Regular Distribution Date (or if such date of determination
         precedes the first Regular Distribution Date, the date of issuance of
         the Old Certificates).
 
DISTRIBUTION UPON OCCURRENCE OF TRIGGERING EVENT
 
     If a Triggering Event shall occur prior to the Delivery Period Termination
Date, the Escrow Agent for each Trust will withdraw any funds then held as
Deposits with respect to such Trust and cause such funds, with accrued and
unpaid interest thereon but without any premium, to be distributed to the
                                       52
<PAGE>   54
 
Certificateholders of such Trust by the Paying Agent on behalf of the Escrow
Agent, after at least 20 days' prior written notice. Accordingly, if a
Triggering Event occurs prior to the Delivery Period Termination Date, the
Trusts will not acquire Equipment Notes issued with respect to Aircraft
delivered after the occurrence of such Triggering Event.
 
DEPOSITARY
 
     ABN AMRO Bank N.V., acting through its Chicago branch, will act as
Depositary.
 
     ABN AMRO Bank N.V. is a direct subsidiary of ABN AMRO Holding N.V., an
international multi-bank holding company. At December 31, 1997, ABN AMRO Holding
N.V. reported consolidated assets amounting to approximately $414 billion (based
on the exchange rate at March 31, 1998 of U.S. $1.00 to NLG 2.08). The
accounting principles applied in the preparation of the financial statements of
ABN AMRO Bank N.V. may not conform to U.S. generally accepted accounting
principles.
 
     ABN AMRO Bank N.V. has long-term unsecured debt ratings of Aa1 from Moody's
and AA from Standard & Poor's and short-term unsecured debt ratings of P-1 from
Moody's and A-I+ from Standard & Poor's.
 
     ABN AMRO Bank N.V.'s Chicago branch was initially licensed by the
Commissioner of Banks and Real Estate for the State of Illinois on October 1,
1973. The Chicago branch is an unincorporated branch of ABN AMRO Bank N.V. and
is not a separate subsidiary. The branch is located at 135 South LaSalle Street,
Chicago, Illinois 60674-9135.
 
                      DESCRIPTION OF THE ESCROW AGREEMENTS
 
     The following summary describes certain material terms of the Escrow
Agreements. The summary does not purport to be complete and is qualified in its
entirety by reference to the provisions of the Escrow Agreements which have been
filed as exhibits to the Registration Statement. Upon request, copies of such
documents will be furnished to any holder of Certificates. Requests for such
documents should be addressed to the Trustees.
 
     Each Escrow Agent, each Paying Agent, each Trustee and the Initial
Purchasers have entered into a separate Escrow Agreement for the benefit of the
Certificateholders of each Trust as holders of the escrow receipts ("Escrow
Receipts") affixed thereto (in such capacity, a "Receiptholder"). The cash
proceeds of the initial sale of Old Certificates of each Trust have been
deposited on behalf of the Escrow Agent (for the benefit of Receiptholders) with
the Depositary as Deposits relating to such Trust. The Escrow Agent of each
Trust has been given irrevocable instructions to permit the Trustee of such
Trust to cause funds to be withdrawn from such Deposits on or prior to the
Delivery Period Termination Date for the purpose of enabling such Trustee to
purchase Equipment Notes on and subject to the terms and conditions of the Note
Purchase Agreement and to direct the Depositary to pay interest on the Deposits
accrued in accordance with the Deposit Agreement to the Paying Agent for
distribution to the Receiptholders.
 
     Each Escrow Agreement requires that the Paying Agent establish and
maintain, for the benefit of the related Receiptholders, one or more Paying
Agent Account(s), which shall be non-interest-bearing. Pursuant to the terms of
the Escrow Agreement, the Paying Agent is required to deposit interest on
Deposits relating to each Trust and any unused Deposits withdrawn by the Escrow
Agent in the Paying Agent Account. All amounts so deposited will be distributed
by the Paying Agent on a Regular Distribution Date or Special Distribution Date,
as appropriate.
 
     Upon receipt by the Depositary on behalf of the Escrow Agent of the cash
proceeds from the Old Certificates as described above, the Escrow Agent issued
Escrow Receipts which were affixed by the relevant Trustee to each Old
Certificate. Each Escrow Receipt evidences a fractional undivided interest in
amounts from time to time deposited into the Paying Agent Account and is limited
in recourse to amounts deposited into such Account. An Escrow Receipt may not be
assigned or transferred except in connection with the assignment or transfer of
the Certificate to which it is affixed. Each Escrow Receipt will be
 
                                       53
<PAGE>   55
 
registered by the Escrow Agent in the same name and manner as the Certificate to
which it is affixed. Escrow Receipts will be affixed to New Certificates issued
pursuant to the Exchange Offer.
 
                    DESCRIPTION OF THE LIQUIDITY FACILITIES
 
     The following summary describes certain terms of the Liquidity Facilities
and certain provisions of the Intercreditor Agreement relating to the Liquidity
Facilities. The summary does not purport to be complete and is qualified in its
entirety by reference to the provisions of the Liquidity Facilities and such
provisions of the Intercreditor Agreement. The provisions of the Liquidity
Facilities are substantially identical except as otherwise indicated. Upon
request, copies of such documents will be furnished to any prospective investor
in the Certificates. Requests for such documents should be addressed to the
Trustees.
 
GENERAL
 
     The Liquidity Provider has entered into a separate revolving credit
agreement (each, a "Liquidity Facility") with the Subordination Agent with
respect to the Certificates of each of the Trusts. Under the Liquidity Facility
with respect to any Trust, the Liquidity Provider will, if necessary, make
advances ("Interest Drawings") in an amount (the "Required Amount") sufficient
to pay interest on the Certificates of such Trust on up to three successive
semi-annual Regular Distribution Dates (without regard to any future payments of
principal on such Certificates) at the respective interest rates shown on the
cover page of this Prospectus (plus an additional margin specified by the
Registration Rights Agreement, if applicable) for such Certificates (the "Stated
Interest Rates"), except that the Liquidity Facility with respect to each Trust
will not cover interest payable by the Depositary on the Deposits relating to
such Trust.
 
     The Liquidity Facility for each Trust is intended to enhance the likelihood
of timely receipt by the Certificateholders of such Trust of the interest
payable on the Certificates of such Trust at the Stated Interest Rate therefor
on up to three consecutive semiannual Regular Distribution Dates. If interest
payment defaults occur which exceed the amount covered by or available under the
Liquidity Facilities for any Trust, the Certificateholders of such Trust will
bear their allocable share of the deficiencies to the extent that there are no
other sources of funds. Although ABN AMRO Bank N.V., acting through its Chicago
branch, is the initial Liquidity Provider for each of the Trusts, ABN AMRO Bank
N.V., acting through its Chicago branch, may be replaced by one or more other
entities with respect to the Trusts under certain circumstances. Therefore, the
Liquidity Provider for each Trust may differ.
 
DRAWINGS
 
     The initial amount available under the Liquidity Facilities for the Class A
Trust, the Class B Trust and the Class C Trust at January 2, 2000, the first
Regular Distribution Date after the scheduled Delivery Period Termination Date,
assuming that Equipment Notes in the maximum principal amount with respect to
all Aircraft are acquired by the Trusts and that all interest and principal due
on or prior to January 2, 2000 is paid, will be $14,212,058, $4,642,845, and
$1,977,379, respectively.
 
     Except as otherwise provided below, the Liquidity Facility for each Trust
will enable the Subordination Agent to make Interest Drawings thereunder on any
Regular Distribution Date to pay interest then due and payable on the
Certificates of such Trust at the Stated Interest Rate for such Trust to the
extent that the amount, if any, available to the Subordination Agent on such
Regular Distribution Date is not sufficient to pay such interest; provided,
however, that the maximum amount available to be drawn under the Liquidity
Facility with respect to any Trust on any Regular Distribution Date to fund any
shortfall of interest on Certificates of such Trust will not exceed the then
Required Amount of such Liquidity Facility less the aggregate amount of each
Interest Drawing outstanding under such Liquidity Facility at such time (the
"Maximum Available Commitment").
 
     The Liquidity Facility for any Trust does not provide for drawings
thereunder to pay for principal of or premium on the Certificates of such Trust
or any interest on the Certificates of such Trust in excess of
 
                                       54
<PAGE>   56
 
the Stated Interest Rate for such Trust or more than three semiannual
installments of interest thereon or principal of or interest or premium on the
Certificates of any other Trust. (Liquidity Facilities, Section 2.02;
Intercreditor Agreement, Section 3.6)
 
     Upon each Interest Drawing under any Liquidity Facility, the Subordination
Agent will be obligated to reimburse (to the extent that the Subordination Agent
has available funds therefor) the Liquidity Provider for the amount of such
drawing. Such reimbursement obligation and any other amounts owing to the
Liquidity Provider under each Liquidity Facility or certain other agreements
(the "Liquidity Obligations") will rank pari passu with the Liquidity
Obligations relating to all other Liquidity Facilities and will rank senior to
the Certificates in right of payment. With respect to any Interest Drawings
under the Liquidity Facility for any Trust, upon reimbursement of the Liquidity
Provider in full for the amount of such Interest Drawings plus interest thereon,
the Maximum Available Commitment under such Liquidity Facility in respect of
interest on the Certificates of such Trust will be reinstated to an amount not
to exceed the then Required Amount of such Liquidity Facility; provided,
however, that such Liquidity Facility will not be so reinstated at any time
after a Liquidity Event of Default shall have occurred and be continuing and
less than 65% of the then aggregate outstanding principal amount of all
Equipment Notes are Performing Equipment Notes.
 
     "Performing Equipment Note" means an Equipment Note with respect to which
no payment default has occurred and is continuing (without giving effect to any
acceleration); provided that in the event of a bankruptcy proceeding involving
America West under the U.S. Bankruptcy Code, the following items will not be
taken into consideration:
 
        (1) any payment default existing during the 60-day period under Section
            1110(a)(1)(A) of the U.S. Bankruptcy Code (or such longer period as
            may apply under Section 1110(b) of the U.S. Bankruptcy Code) (the
            "Section 1110 Period"), unless during the Section 1110 Period the
            trustee in such proceeding or America West refuses to assume or
            agree to perform its obligations under the Lease relating to such
            Equipment Note (in the case of a Leased Aircraft) or under the Owned
            Aircraft Indenture related to such Equipment Note (in the case of an
            Owned Aircraft; and
 
          (2) any payment default occurring after the date of the order of
              relief in such proceeding, if such payment default is cured under
              Section 1110(a)(1)(B) of the U.S. Bankruptcy Code before the later
              of 30 days after the date of such default or the expiration of the
              Section 1110 Period.
 
     A "Non-Performing Equipment Note" refers to any Equipment Notes other than
the Performing Equipment Notes.
 
     With respect to any other drawings under such Liquidity Facility, amounts
available to be drawn thereunder are not subject to reinstatement. The Required
Amount of the Liquidity Facility for any Trust will be automatically increased
or reduced from time to time to an amount equal to the next three successive
interest payments due on the Certificates of such Trust (without regard to
expected future payment of principal of such Certificates) at the Stated
Interest Rate for such Trust, but excluding interest payable by the Depositary
as described above. (Liquidity Facilities, Section 2.04(a); Intercreditor
Agreement, Section 3.6(g))
 
     Possible Replacement of the Liquidity Facility
 
     If at any time the short-term unsecured debt rating of the Liquidity
Provider for any Trust then issued by either Rating Agency is lower than the
Threshold Rating, the Liquidity Facility provided by such Liquidity Provider for
the related Class of Certificates will be required to be replaced. In the event
that such Liquidity Facility is not replaced within ten days after notice of the
downgrading and as otherwise provided in the Intercreditor Agreement, such
Liquidity Facility will be drawn in full up to the Maximum Available Commitment
thereunder (the "Downgrade Drawing") and the proceeds will be deposited into a
 
                                       55
<PAGE>   57
 
cash collateral account (the "Cash Collateral Account") for the related Class of
Certificates and subject to the same conditions as cash payments of Interest
Drawings under such Liquidity Facility would be used. (Liquidity Facilities,
Section 2.02(c); Intercreditor Agreement, Section 3.6(c))
 
     Definitions of Replacement Facility and Threshold Rating
 
     A "Replacement Facility" for any Liquidity Facility means an irrevocable
liquidity facility in substantially the form of the replaced Liquidity Facility,
including reinstatement provisions, or in such other form (which may include a
letter of credit) as shall permit the Rating Agencies to confirm in writing
their respective ratings then in effect for the Certificates (before the
downgrading of such ratings, if any, as a result of the downgrading of the
Liquidity Provider), in a face amount equal to the amount of interest payable on
the Certificates of such Trust (at the Stated Interest Rate for such Trust, and
without regard to expected future principal payments) on the three Regular
Distribution Dates following the date of replacement of such Liquidity Facility
(which will not cover scheduled interest payments with respect to the Deposits
relating to such Trust) and issued by a Person having unsecured short-term debt
ratings issued by both Rating Agencies which are equal to or higher than the
Threshold Rating. (Intercreditor Agreement, Section 1.1)
 
     "Threshold Rating" means the short-term unsecured debt rating of P-1 by
Moody's and A-1+ by Standard & Poor's in the case of the Class A Liquidity
Facility, and the short-term unsecured debt rating of P-1 by Moody's and A-1 by
Standard & Poor's in the case of the Class B Liquidity Facility and the Class C
Liquidity Facility.
 
     Expiration of Liquidity Provider's Obligations
 
     The Liquidity Facility for each Trust provides that the relevant Liquidity
Provider's obligations thereunder will expire on the earliest of the following:
 
     (1) 364 days after the Issuance Date.
 
     (2) The date on which the Subordination Agent delivers to such Liquidity
         Provider a certification that all of the Certificates of such Trust
         have been paid in full.
 
     (3) The date on which the Subordination Agent delivers to such Liquidity
         Provider a certification that a Replacement Facility has been
         substituted for such Liquidity Facility.
 
     (4) The fifth Business Day following receipt by the Subordination Agent of
         a Termination Notice from such Liquidity Provider (see "-- Liquidity
         Events of Default").
 
     (5) The date on which no amount is or may (by reason of reinstatement)
         become available for drawing under such Liquidity Facility.
 
     Each Liquidity Facility provides that the scheduled expiration date thereof
may be extended for additional 364-day periods by mutual agreement.
 
     Replacement of any Liquidity Facility
 
     The Intercreditor Agreement will provide for the replacement of any
Liquidity Facility for any Trust (other than a Liquidity Facility which expires
no earlier than 15 days later than the Final Legal Distribution Date for the
related Class) in the event that such Liquidity Facility is not extended at
least 25 days prior to its then scheduled expiration date. In the event such
Liquidity Facility is not so extended or replaced by the 25th day prior to its
then scheduled expiration date, such Liquidity Facility will be drawn in full up
to the then Maximum Available Commitment (the "Non-Extension Drawing") and the
proceeds will be deposited in the Cash Collateral Account for the related Class
of Certificates and used for the same purposes and under the same circumstances,
and subject to the same conditions, as cash payments of Interest Drawings under
such Liquidity Facility would be used. (Liquidity Facilities, Section 2.02(b))
 
                                       56
<PAGE>   58
 
     America West may, at its option, arrange for a Replacement Facility at any
time to replace the Liquidity Facility for any Trust (including without
limitation any Replacement Facility described in the following sentence). In
addition, if any Liquidity Provider shall determine not to extend its Liquidity
Facility, then such Liquidity Provider may, at its option, arrange for a
Replacement Facility to replace such Liquidity Facility during the period no
earlier than 40 days and no later than 25 days prior to the then scheduled
expiration date of such Liquidity Facility. If any Replacement Facility is
provided at any time after a Downgrade Drawing or a Non-Extension Drawing under
any Liquidity Facility, the funds with respect to such Liquidity Facility on
deposit in the Cash Collateral Account for such Trust will be returned to the
Liquidity Provider being replaced. (Intercreditor Agreement, Section 3.6(e))
 
     Final Drawing Upon Termination of any Liquidity Facility
 
     The Intercreditor Agreement provides that, upon receipt by the
Subordination Agent of a Termination Notice with respect to any Liquidity
Facility from the Liquidity Provider (given as described in "-- Liquidity Events
of Default"), the Subordination Agent will request a final drawing (the "Final
Drawing") under such Liquidity Facility in an amount equal to the then Maximum
Available Commitment thereunder and will hold the proceeds thereof in the Cash
Collateral Account for the related Trust as cash collateral to be used for the
same purposes and under the same circumstances, and subject to the same
conditions, as cash payments of Interest Drawings under such Liquidity Facility
would be used. (Liquidity Facilities, Section 2.02(d); Intercreditor Agreement,
Section 3.6(i))
 
     Mechanics of Drawings
 
     Drawings under any Liquidity Facility will be made by delivery by the
Subordination Agent of a certificate in the form required by such Liquidity
Facility. Upon receipt of such a certificate, the Liquidity Provider is
obligated to make payment of the drawing requested thereby in immediately
available funds. Upon payment by any Liquidity Provider of the amount specified
in any drawing under any Liquidity Facility, such Liquidity Provider will be
fully discharged of its obligations under such Liquidity Facility with respect
to such drawing and will not thereafter be obligated to make any further
payments under such Liquidity Facility in respect of such drawing to the
Subordination Agent or any other person.
 
REIMBURSEMENT OF DRAWINGS
 
     Amounts drawn under any Liquidity Facility by reason of an Interest Drawing
or the Final Drawing will be immediately due and payable, together with interest
on the amount of such drawing, with respect to the period from the date of its
borrowing to (but excluding) the third business day following the applicable
Liquidity Provider's receipt of the notice of such Interest Drawing, at the Base
Rate plus 1% per annum, and thereafter, at LIBOR for the applicable Interest
Period plus 1.75% per annum, provided that the Subordination Agent will be
obligated to reimburse such amounts only to the extent that the Subordination
Agent has funds available therefor.
 
     Definitions of LIBOR and Base Rate
 
     "LIBOR" means, with respect to any interest period, the rate per annum
appearing on Page 3750 of the Dow Jones Markets Service (or any successor or
substitute page of such service, or any successor to or substitute for such
service, providing rate quotations comparable to those currently provided on
such page applicable to deposits in dollars in the London interbank market) at
approximately 11:00 a.m. (London time) two Business Days before the first day of
such interest period for a period of time comparable to such interest period. In
the event that such rate is not available at such time for any reason, then
LIBOR with respect to any interest period shall be the rate per annum at which
deposits in dollars are offered to major banks in the London interbank market at
approximately 11:00 a.m. (London time) two Business Days before the first day of
such interest period for a period of time comparable to such interest period.
 
                                       57
<PAGE>   59
 
     "Base Rate" means a fluctuating interest rate per annum in effect from time
to time, which rate per annum shall at all times be determined by the
calculation set forth below:
 
        Calculation of Base Rate
 
        (1) The weighted average of the rates on overnight Federal funds
            transactions with members of the Federal Reserve System arranged by
            Federal funds brokers, as published for such day (or, if such day is
            not a business day, the next preceding business day) by the Federal
            Reserve Bank of New York, or if such rate is not so published for
            any day that is a business day, the average of the quotations for
            such day for such transactions received by the Liquidity Provider
            from three Federal funds brokers of recognized standing selected by
            it, plus
 
        (2) One-quarter of one percent ( 1/4 of 1%).
 
     Downgrade Drawing or Non-Extension Drawing
 
     The amount drawn under the Liquidity Facility for any Trust by reason of a
Downgrade Drawing or a Non-Extension Drawing will be treated as set forth below:
 
        Treatment of Amount Drawn Under a Liquidity Facility
 
        (1) Such amount will be released on any Distribution Date to the
            Liquidity Provider to the extent that such amount exceeds the
            Required Amount.
 
        (2) Any portion of such amount withdrawn from the Cash Collateral
            Account for such Certificates to pay interest on such Certificates
            will be treated in the same way as Interest Drawings.
 
        (3) The balance of such amount will be invested in Eligible Investments.
 
     The Downgrade Drawing or Non-Extension Drawing under any Liquidity Facility
(other than any portion thereof applied to the payment of interest on the
Certificates) will bear interest with respect to the period from the date of
borrowing to (but excluding) the third Business Day following the Liquidity
Provider's receipt of the notice of such Downgrade Drawing or Non-Extension
Drawing, at the Base Rate, and thereafter at LIBOR for the applicable interest
period plus 0.35% per annum; provided that the Subordination Agent will be
obligated to pay such amount only to the extent that the Subordination Agent has
funds available therefor. (Liquidity Facilities, Section 2.06)
 
LIQUIDITY EVENTS OF DEFAULT
 
     Events of Default under each Liquidity Facility (each, a "Liquidity Event
of Default") will consist of the acceleration of all the Equipment Notes
(provided, that during the Delivery Period the aggregate principal amount
thereof exceeds $125 million) and (ii) certain bankruptcy or similar events
involving America West. (Liquidity Facilities, Section 1.01)
 
     If any Liquidity Event of Default under any Liquidity Facility has occurred
and is continuing and less than 65% of the aggregate outstanding principal
amount of all Equipment Notes are Performing Equipment Notes, the applicable
Liquidity Provider may, in its discretion, give a notice of termination of the
related Liquidity Facility (a "Termination Notice") the effect of which will be
as follows:
 
        Effect of Notice of Termination Due to Liquidity Event of Default
 
        (1) Such Liquidity Facility will expire on the fifth Business Day after
            the date on which such Termination Notice is received by the
            Subordination Agent.
 
        (2) The Subordination Agent will promptly request, and the Liquidity
            Provider will make, a Final Drawing thereunder in an amount equal to
            the then Maximum Available Commitment thereunder.
 
                                       58
<PAGE>   60
 
        (3) Any Drawing remaining unreimbursed as of the date of termination
            will be automatically converted into a Final Drawing under such
            Liquidity Facility.
 
        (4) All amounts owing to such Liquidity Provider will automatically
            become accelerated.
 
Notwithstanding the foregoing, the Subordination Agent will be obligated to pay
amounts owing to the Liquidity Provider only to the extent of funds available
therefor after giving effect to the payments in accordance with the provisions
set forth under "Description of the Intercreditor Agreement -- Priority of
Distributions". (Liquidity Facilities, Section 6.01) Upon the circumstances
described below under "Description of the Intercreditor
Agreement -- Intercreditor Rights", a Liquidity Provider may become the
Controlling Party with respect to the exercise of remedies under the Indentures.
(Intercreditor Agreement, Section 2.6(c))
 
LIQUIDITY PROVIDER
 
     The initial Liquidity Provider for each Trust will be ABN AMRO Bank N.V., a
Dutch bank acting through its Chicago branch. ABN AMRO Bank N.V. has short term
debt ratings of P-1 from Moody's and A-1+ from Standard & Poor's.
 
                   DESCRIPTION OF THE INTERCREDITOR AGREEMENT
 
     The following summary describes certain provisions of the Intercreditor
Agreement. The summary does not purport to be complete and is qualified in its
entirety by reference to the provisions of the Intercreditor Agreement. Upon
request, copies of the Intercreditor Agreement will be furnished to any
prospective investor in the Certificates. Requests for such document should be
addressed to the Trustees.
 
INTERCREDITOR RIGHTS
 
     Controlling Party
 
     Pursuant to the Intercreditor Agreement, the Trustees and the Liquidity
Provider will agree that, with respect to any Indenture at any given time, the
Loan Trustee will be directed in taking, or refraining from taking, any action
thereunder or with respect to the Equipment Notes issued thereunder, by the
holders of at least a majority of the outstanding principal amount of the
Equipment Notes issued thereunder (provided that, for so long as the
Subordination Agent is the registered holder of the Equipment Notes, the
Subordination Agent will act in accordance with the directions of the Trustees
(in the case of each such Trustee, with respect to the Equipment Notes issued
under such Indenture and held as Trust Property of such Trust) constituting, in
the aggregate, directions with respect to such principal amount of Equipment
Notes), so long as no Indenture Default (which, with respect to Leased Aircraft,
has not been cured by the applicable Owner Trustee or Owner Participant) shall
have occurred and be continuing thereunder. Additionally, the Loan Trustee will
be directed after the occurrence and during the continuance of an Indenture
Default thereunder (which, with respect to Leased Aircraft, has not been cured
by the applicable Owner Trustee or Owner Participant), in taking, or refraining
from taking, any action thereunder or with respect to the Equipment Notes issued
thereunder, including exercising remedies thereunder or with respect to such
Equipment Notes (including acceleration of such Equipment Notes or foreclosing
the lien on the Aircraft securing such Equipment Notes), by the Controlling
Party, subject to the limitations described below. See "Description of the
Certificates -- Indenture Defaults and Certain Rights Upon an Indenture Default"
for a description of the rights of the Certificateholders of each Trust to
direct the respective Trustees.
 
     "Controlling Party" with respect to any Indenture means the Class A
Trustee, the Class B Trustee (upon payment of Final Distributions to the holders
of Class A Certificates) and the Class C Trustee (upon payment of Final
Distributions to the holders of Class B Certificates). Notwithstanding the
foregoing, at any time after 18 months from the earliest to occur of certain
events set forth below, the Liquidity Provider with the highest outstanding
amount of unreimbursed Liquidity Obligations will have the right to elect to
become the Controlling Party with respect to any Indenture.
 
                                       59
<PAGE>   61
 
          Events Precedent to Liquidity Provider Electing to Become Controlling
     Party
 
          (1) The date on which the entire available amount under any Liquidity
              Facility shall have been drawn (for any reason other than a
              Downgrade Drawing or a Non-Extension Drawing) and remain
              unreimbursed.
 
          (2) The entire amount of any Downgrade Drawing or Non-Extension
              Drawing shall have been withdrawn from the relevant Cash
              Collateral Account to pay interest on the relevant Class of
              Certificates and remain unreimbursed.
 
          (3) The date on which all Equipment Notes shall have been accelerated
              (provided, that prior to the Delivery Period Termination Date the
              aggregate outstanding principal amount thereof exceeds $125
              million).
 
For purposes of giving effect to the foregoing, the Trustees (other than the
Controlling Party) have irrevocably agreed, and the Certificateholders (other
than the Certificateholders represented by the Controlling Party) will be deemed
to agree by virtue of their purchase of Certificates, that the Subordination
Agent, as record holder of the Equipment Notes, shall exercise its voting rights
in respect of the Equipment Notes as directed by the Controlling Party.
(Intercreditor Agreement, Section 2.6) For a description of certain limitations
on the Controlling Party's rights to exercise remedies, see "Description of the
Equipment Notes -- Remedies".
 
     "Final Distributions," with respect to the Certificates of any Trust on any
Distribution Date, shall be calculated under the following formula:
 
        Calculation of Final Distributions
 
          (1) The aggregate amount of all accrued and unpaid interest on such
              Certificates (excluding interest payable on the Deposits relating
              to such Trust), plus
 
          (2) the Pool Balance of such Certificates as of the immediately
              preceding Distribution Date (less the amount of the Deposits for
              such Class of Certificates as of such preceding Distribution Date
              other than any portion of such Deposits thereafter used to acquire
              Equipment Notes pursuant to the Note Purchase Agreement).
 
For purposes of calculating Final Distributions with respect to the Certificates
of any Trust, any premium paid on the Equipment Notes held in such Trust which
has not been distributed to the Certificateholders of such Trust (other than
such premium or a portion thereof applied to the payment of interest on the
Certificates of such Trust or the reduction of the Pool Balance of such Trust)
shall be added to the amount of such Final Distributions.
 
          (1) Upon the occurrence and during the continuation of any Indenture
              Default under any Indenture, the Controlling Party may accelerate
              and sell all (but not less than all) of the Equipment Notes issued
              under such Indenture to any person, subject to the provisions of
              paragraph (2) below. The proceeds of such sale will be distributed
              pursuant to the provisions of the Intercreditor Agreement.
 
        (2) So long as any Certificates are outstanding, during nine months
            after the earlier of the acceleration of the Equipment Notes under
            any Indenture or the bankruptcy or insolvency of America West,
            without the consent of each Trustee, (a) no Aircraft subject to the
            lien of such Indenture or such Equipment Notes may be sold, if the
            net proceeds from such sale would be less than the Minimum Sale
            Price for such Aircraft or such Equipment Notes, and (b) with
            respect to any Leased Aircraft, the amount and payment dates of
            rentals payable by America West under the Lease for such Leased
            Aircraft may not be adjusted, if, as a result of such adjustment,
            the discounted present value of all such rentals would be less than
            75% of the discounted present value of the rentals payable by
            America West under such Lease before giving effect to such
            adjustment, in each case, using the weighted average interest rate
            of the Equipment Notes issued under such Indenture as the discount
            rate.
 
                                       60
<PAGE>   62
 
     Sale of Equipment Notes or Aircraft
 
     Upon the occurrence and during the continuation of any Indenture Default
under any Indenture, the Controlling Party may accelerate and, subject to the
provisions of the immediately following sentence, sell all (but not less than
all) of the Equipment Notes issued under such Indenture to any person. So long
as any Certificates are outstanding, during nine months after the earlier of the
acceleration of the Equipment Notes under any Indenture and the bankruptcy or
insolvency of America West, without the consent of each Trustee, no Aircraft
subject to the lien of such Indenture or such Equipment Notes may be sold, if
the net proceeds from such sale would be less than the Minimum Sale Price for
such Aircraft or such Equipment Notes, and with respect to any Leased Aircraft,
the amount and payment dates of rentals payable by America West under the Lease
for such Leased Aircraft may not be adjusted, if, as a result of such
adjustment, the discounted present value of all such rentals would be less than
75% of the discounted present value of the rentals payable by America West under
such Lease before giving effect to such adjustment, in each case, using the
weighted average interest rate of the Equipment Notes issued under such
Indenture as the discount rate. (Intercreditor Agreement, Section 4.1(a))
 
     "Minimum Sale Price" means, with respect to any Aircraft or the Equipment
Notes issued in respect of such Aircraft, at any time, the lesser of 75% of the
Appraised Current Market Value of such Aircraft and the aggregate outstanding
principal amount of such Equipment Notes, plus accrued and unpaid interest
thereon.
 
     The Subordination Agent may from time to time during the continuance of an
Indenture Default (and before the occurrence of a Triggering Event) commission
LTV Appraisals with respect to an Aircraft at the request of the Controlling
Party. (Intercreditor Agreement, Section 4.1(a) (iii))
 
PRIORITY OF DISTRIBUTIONS
 
     Priority of Distributions in the Absence of a Triggering Event
 
     So long as no Triggering Event shall have occurred, the payments in respect
of the Equipment Notes and certain other payments received on any Distribution
Date will be promptly distributed by the Subordination Agent on such
Distribution Date in the following order of priority:
 
     Priority of Distributions
 
     (1) To pay the Liquidity Obligations (other than any interest accrued
         thereon or the principal amount of any Drawing) (the "Liquidity
         Expenses") to the Liquidity Provider.
 
     (2) To pay interest accrued on the Liquidity Obligations to the Liquidity
         Provider.
 
     (3) To pay or reimburse the Liquidity Provider for the Liquidity
         Obligations (other than amounts payable pursuant to clauses (1) and (2)
         above) and/or, if applicable, to replenish each Cash Collateral Account
         up to the applicable Required Amount.
 
     (4) To pay Expected Distributions on the Class A Certificates to the
         holders of Class A Certificates.
 
     (5) To pay Expected Distributions on the Class B Certificates to the
         holders of Class B Certificates.
 
     (6) To pay Expected Distributions on the Class C Certificates to the
         holders of Class C Certificates.
 
     (7) If Class D Certificates have been issued, to pay "Expected
         Distributions" (to be defined in a manner equivalent to the definition
         below for other Classes of Certificates) on the Class D Certificates to
         the holders of Class D Certificates.
 
     (8) To pay certain fees and expenses of the Subordination Agent and the
         Trustees.
 
     Priority of Distributions In the Event of a Triggering Event
 
     Subject to the terms of the Intercreditor Agreement, upon the occurrence of
a Triggering Event and at all times thereafter, all funds received by the
Subordination Agent in respect of the Equipment Notes
 
                                       61
<PAGE>   63
 
and certain other payments will be promptly distributed by the Subordination
Agent in the following order of priority:
 
     Priority of Distributions
 
     (1) To pay certain out-of-pocket costs and expenses actually incurred by
         the Subordination Agent or any Trustee or to reimburse any
         Certificateholder or the Liquidity Provider in respect of payments made
         to the Subordination Agent or any Trustee in connection with the
         protection or realization of the value of the Equipment Notes or any
         Trust Indenture Estate (the "Administration Expenses").
 
     (2) To the Liquidity Provider, to pay the Liquidity Expenses.
 
     (3) To the Liquidity Provider, to pay interest accrued on the Liquidity
         Obligations.
 
     (4) To the Liquidity Provider, to pay the outstanding amount of all
         Liquidity Obligations and/or, if applicable, with respect to any
         particular Liquidity Facility, unless (a) less than 65% of the
         aggregate outstanding principal amount of all Equipment Notes are
         Performing Equipment Notes and a Liquidity Event of Default shall have
         occurred and be continuing under such Liquidity Facility or (b) a Final
         Drawing shall have occurred under such Liquidity Facility, to replenish
         the Cash Collateral Account with respect to such Liquidity Facility up
         to the Required Amount for the related Class of Certificates (less the
         amount of any repayments of Interest Drawings under such Liquidity
         Facility while sub-clause (a) is applicable).
 
     (5) To pay certain fees, taxes, charges and other amounts payable to the
         Subordination Agent, any Trustee or any Certificateholder.
 
     (6) To pay Adjusted Expected Distributions on the Class A Certificates to
         the holders of Class A Certificates.
 
     (7) To pay Adjusted Expected Distributions on the Class B Certificates to
         the holders of Class B Certificates.
 
     (8) To pay Adjusted Expected Distributions on the Class C Certificates to
         the holders of Class C Certificates.
 
     (9) If Class D Certificates have been issued, to pay "Adjusted Expected
         Distributions" (to be defined in a manner equivalent to the definition
         below for other Classes of Certificates) on the Class D Certificates to
         the holders of Class D Certificates.
 
     Definitions of Expected Distributions and Adjusted Expected Distributions
 
     "Expected Distributions" means, with respect to the Certificates of any
Trust on any on any Distribution Date (the "Current Distribution Date"), shall
be determined by the following formula:
 
        Calculation of Expected Distributions
 
        (1) Accrued and unpaid interest on such Certificates (excluding
            interest, if any, payable with respect to the Deposits relating to
            such Trust), plus
 
        (2) The difference between
 
             (a) the Pool Balance of such Certificates as of the immediately
                 preceding Distribution Date (or, if the Current Distribution
                 Date is the first Distribution Date, the original aggregate
                 face amount of the Certificates of such Trust) and
 
             (b) the Pool Balance of such Certificates as of the Current
                 Distribution Date calculated on the basis that (i) the
                 principal of the Equipment Notes held in such Trust has been
                 paid when due (whether at stated maturity, upon redemption,
                 prepayment, purchase or acceleration or otherwise) and such
                 payments have been distributed to the holders of such
                 Certificates and (ii) the principal of any Equipment Notes
                 formerly held in such
                                       62
<PAGE>   64
 
               Trust that have been sold pursuant to the Intercreditor Agreement
               has been paid in full and such payments have been distributed to
               the holders of such Certificates, but without giving effect to
               any reduction in the Pool Balance as a result of any distribution
               attributable to Deposits occurring after the immediately
               preceding Distribution Date (or, if the Current Distribution Date
               is the first Distribution Date, occurring after the initial
               issuance of the Certificates of such Trust).
 
For purposes of determining the priority of distributions on account of the
redemption, purchase or prepayment of all of the Equipment Notes issued pursuant
to an Indenture, clause (1) of the definition of Expected Distributions shall be
deemed to read as follows: "(1) Accrued, due and unpaid interest on such
Certificates (excluding interest, if any, payable with respect to the Deposits
relating to such Trust) together with (without duplication) accrued and unpaid
interest on a portion of such Certificates equal to the outstanding principal
amount of the Equipment Notes being redeemed, purchased or prepaid (immediately
prior to such redemption, purchase or prepayment)."
 
     "Adjusted Expected Distributions" means, with respect to the Certificates
of any Trust on any Current Distribution Date, shall be determined by the
following formula:
 
        Calculation of Adjusted Expected Distributions
 
        (1) Accrued and unpaid interest on such Certificates (excluding
            interest, if any, payable with respect to the Deposits relating to
            such Trust), plus
 
        (2) The greater of:
 
             (a) the difference between
 
                (x) the Pool Balance of such Certificates as of the immediately
                    preceding Distribution Date (or, if the Current Distribution
                    Date is the first Distribution Date, the original aggregate
                    face amount of the Certificates of such Trust) and
 
                (y) the Pool Balance of such Certificates as of the Current
                    Distribution Date calculated on the basis that (i) the
                    principal of the Non-Performing Equipment Notes held in such
                    Trust has been paid in full and such payments have been
                    distributed to the holders of such Certificates, (ii) the
                    principal of the Performing Equipment Notes held in such
                    Trust has been paid when due (but without giving effect to
                    any acceleration of Performing Equipment Notes) and such
                    payments have been distributed to the holders of such
                    Certificates and (iii) the principal of any Equipment Notes
                    formerly held in such Trust that have been sold pursuant to
                    the Intercreditor Agreement has been paid in full and such
                    payment has been distributed to the holders of such
                    Certificates, but without giving effect to any reduction in
                    the Pool Balance as a result of any distribution
                    attributable to Deposits occurring after the immediately
                    preceding Distribution Date (or, if the Current Distribution
                    Date is the first Distribution Date, occurring after the
                    initial issuance of the Certificates of such Trust); and
 
             (b) the amount of the excess, if any, of (i) the Pool Balance of
                 such Class of Certificates as of the immediately preceding
                 Distribution Date (or, if the Current Distribution Date is the
                 first Distribution Date, the original aggregate face amount of
                 the Certificates of such Trust) (less the amount of the
                 Deposits for such Class of Certificates as of such preceding
                 Distribution Date (or, if the Current Distribution Date is the
                 first Distribution Date, the original aggregate amount of the
                 Deposits for such Class of Certificates) other than any portion
                 of such Deposits thereafter used to acquire Equipment Notes
                 pursuant to the Note Purchase Agreement), over (ii) the
                 Aggregate LTV Collateral Amount for such Class of Certificates
                 for the Current Distribution Date; provided that, until the
                 date of the initial LTV Appraisals, this clause (B) shall not
                 apply.
 
                                       63
<PAGE>   65
 
For purposes of calculating Expected Distributions or Adjusted Expected
Distributions with respect to the Certificates of any Trust, any premium paid on
the Equipment Notes held in such Trust that has not been distributed to the
Certificateholders of such Trust (other than such premium or a portion thereof
applied to the payment of interest on the Certificates of such Trust or the
reduction of the Pool Balance of such Trust) shall be added to the amount of
Expected Distributions or Adjusted Expected Distributions.
 
     Other Definitions
 
     "Aggregate LTV Collateral Amount" for any Class of Certificates for any
Distribution Date means the sum of the applicable LTV Collateral Amounts for
each Aircraft, minus the Pool Balance for each Class of Certificates, if any,
senior to such Class, after giving effect to any distribution of principal on
such Distribution Date with respect to such senior Class or Classes.
 
     "LTV Collateral Amount" of any Aircraft for any Class of Certificates
means, as of any Distribution Date, the lesser of (a) the LTV Ratio for such
Class of Certificates multiplied by the Appraised Current Market Value of such
Aircraft (or with respect to any such Aircraft which has suffered an Event of
Loss under and as defined in the relevant Lease, in the case of a Leased
Aircraft, or Indenture, in the case of an Owned Aircraft, the amount of the
insurance proceeds paid to the related Loan Trustee in respect thereof to the
extent then held by such Loan Trustee (and/or on deposit in the Special Payments
Account) or payable to such Loan Trustee in respect thereof) and (b) the
outstanding principal amount of the Equipment Notes secured by such Aircraft
after giving effect to any principal payments of such Equipment Notes on or
before such Distribution Date.
 
     "LTV Ratio" means, for the Class A Certificates, 43%, for the Class B
Certificates, 57% and for the Class C Certificates, 71%.
 
     "Appraised Current Market Value" of any Aircraft means the lower of the
average and the median of the most recent three LTV Appraisals of such Aircraft.
After a Triggering Event occurs and any Equipment Note becomes a Non-Performing
Equipment Note, the Subordination Agent shall obtain LTV Appraisals for all of
the Aircraft as soon as practicable and additional LTV Appraisals on or prior to
each anniversary of the date of such initial LTV Appraisals; provided that if
the Controlling Party reasonably objects to the appraised value of the Aircraft
shown in such LTV Appraisals, the Controlling Party shall have the right to
obtain or cause to be obtained substitute LTV Appraisals (including LTV
Appraisals based upon physical inspection of such Aircraft).
 
     "LTV Appraisal" means a fair market value appraisal (which may be a
"desktop" appraisal) performed by any Appraiser or any other nationally
recognized appraiser on the basis of an arm's-length transaction between an
informed and willing purchaser under no compulsion to buy and an informed and
willing seller under no compulsion to sell and both having knowledge of all
relevant facts.
 
     Miscellaneous
 
     Interest Drawings under the Liquidity Facility and withdrawals from the
Cash Collateral Account, in each case in respect of interest on the Certificates
of any Trust, will be distributed to the Trustee for such Trust, notwithstanding
the priority of distributions set forth in the Intercreditor Agreement and
otherwise described herein.
 
     All amounts on deposit in the Cash Collateral Account for any Trust that
are in excess of the Required Amount will be paid to the applicable Liquidity
Provider.
 
VOTING OF EQUIPMENT NOTES
 
     In the event that the Subordination Agent, as the registered holder of any
Equipment Note, receives a request for its consent to any amendment,
modification, consent or waiver under such Equipment Note or the related
Indenture (or, if applicable, the Lease, the Participation Agreement or other
related document), the Subordination Agent shall take certain actions depending
on whether an Indenture Default shall have occurred and be continuing. If no
Indenture Default shall have occurred and be continuing with
                                       64
<PAGE>   66
 
respect to such Indenture, the Subordination Agent shall request direction with
respect to each such Series of Equipment Notes from the Trustee of the Trust
which holds such Equipment Notes and shall vote or consent in accordance with
the directions of such Trustee. If any Indenture Default shall have occurred and
be continuing with respect to such Indenture, the Subordination Agent will
exercise its voting rights as directed by the Controlling Party, subject to
certain limitations; provided that no such amendment, modification, consent or
waiver shall, without the consent of the Liquidity Provider, reduce the amount
of rent, supplemental rent or stipulated loss values payable by America West
under any Lease or reduce the amount of principal or interest payable by America
West under any Equipment Note issued under any Owned Aircraft Indenture.
(Intercreditor Agreement, Section 9.1)
 
ADDITION OF TRUSTEE FOR CLASS D CERTIFICATES
 
     If the Class D Certificates are issued, the Class D Trustee will become a
party to the Intercreditor Agreement. (Intercreditor Agreement, Section 9.1(c))
 
THE SUBORDINATION AGENT
 
     Wilmington Trust Company will be the Subordination Agent under the
Intercreditor Agreement. America West and its affiliates may from time to time
enter into banking and trustee relationships with the Subordination Agent and
its affiliates. The Subordination Agent's address is Rodney Square North, 1100
North Market Street, Wilmington, Delaware, Attention: Corporate Trust
Administration.
 
     The Subordination Agent may resign at any time, in which event a successor
Subordination Agent will be appointed as provided in the Intercreditor
Agreement. The Controlling Party may remove the Subordination Agent for cause as
provided in the Intercreditor Agreement. In such circumstances, a successor
Subordination Agent will be appointed as provided in the Intercreditor
Agreement. Any resignation or removal of the Subordination Agent and appointment
of a successor Subordination Agent does not become effective until acceptance of
the appointment and assumption of its obligations by the successor Subordination
Agent. (Intercreditor Agreement, Section 8.1)
 
                 DESCRIPTION OF THE AIRCRAFT AND THE APPRAISALS
 
THE AIRCRAFT
 
     The Aircraft consist of six Airbus A319-132 aircraft and two Airbus
A320-232 aircraft, all of which will be newly or recently delivered by the
manufacturer at the time that the Equipment Notes relating thereto are issued.
The Aircraft have been designed to be in compliance with Stage III noise level
standards, which are the most restrictive regulatory standards currently in
effect in the United States for aircraft noise abatement.
 
     The Airbus A319-100 aircraft is a medium range aircraft with a seating
capacity of approximately 124 passengers. The engine type utilized on America
West's A319-132 aircraft is expected to be International Aero Engines V2524-A5
engines.
 
     The Airbus A320-200 aircraft is a medium range aircraft with a seating
capacity of approximately 150 passengers. The engine type utilized on American
West's A320-232 aircraft is expected to be International Aero Engines V2527-A5
engines.
 
                                       65
<PAGE>   67
 
THE APPRAISALS
 
     The table below sets forth the appraised values and certain additional
information regarding the Aircraft.
 
<TABLE>
<CAPTION>
                         EXPECTED        EXPECTED                                     APPRAISED VALUE
                       REGISTRATION   MANUFACTURER'S                     ------------------------------------------
AIRCRAFT TYPE             NUMBER      SERIAL NUMBER    DELIVERY MONTH*      AVITAS      AVSOLUTIONS         BK
- -------------          ------------   --------------   ---------------   ------------   ------------   ------------
<S>                    <C>            <C>              <C>               <C>            <C>            <C>
Airbus A319-132           N801AW            889         October 1998     $ 38,000,000   $ 38,140,000   $ 33,000,000
Airbus A319-132           N802AW            924        December 1998       38,000,000     38,140,000     33,100,000
Airbus A319-132           N803AW            931        December 1998       38,000,000     38,140,000     33,100,000
Airbus A319-132           N804AW           1049          July 1999         40,600,000     39,280,000     33,500,000
Airbus A319-132           N805AW           1056          July 1999         40,600,000     39,280,000     33,500,000
Airbus A319-132           N806AW           1071         August 1999        40,600,000     39,280,000     33,600,000
Airbus A320-232           N652AW            953        February 1999       45,500,000     44,390,000     39,700,000
Airbus A320-232           N653AW           1003           May 1999         46,200,000     44,720,000     39,800,000
                                                                         ------------   ------------   ------------
                                                                         $327,500,000   $321,370,000   $279,300,000
                                                                         ============   ============   ============
</TABLE>
 
- -------------------------
* Reflects the originally scheduled delivery month under America West's purchase
  agreement with the manufacturer. The actual delivery date for any Aircraft may
  be subject to change. The delivery month for Aircraft N806AW has been changed
  to July 1999. See "-- Deliveries of Aircraft".
 
     The appraised values set forth in the foregoing chart were determined by
the following three independent aircraft appraisal and consulting firms:
AvSolutions, AVITAS and BK. Each Appraiser was asked to provide its opinion as
to the appraised value of each Aircraft as of September 24, 1998, and projected
as of the scheduled delivery month of each such Aircraft. As part of this
process, all three Appraisers performed "desk-top" appraisals without any
physical inspection of the Aircraft. The appraisals are based on various
assumptions and methodologies, which vary among the appraisals. The Appraisers
have delivered letters summarizing their respective appraisals, copies of which
are annexed to this Prospectus as Appendix II. For a discussion of the
assumptions and methodologies used in each of the appraisals, reference is
hereby made to such summaries.
 
     An appraisal is only an estimate of value, is not indicative of the price
at which an aircraft may be purchased from the manufacturer and should not be
relied upon as a measure of realizable value; the proceeds realized upon a sale
of any Aircraft may be less than the appraised value thereof. The value of the
Aircraft in the event of the exercise of remedies under the applicable Indenture
will depend on market and economic conditions, the availability of buyers, the
condition of the Aircraft and other similar factors. Accordingly, there can be
no assurance that the proceeds realized upon any such exercise with respect to
the Equipment Notes and the Aircraft pursuant to the applicable Indenture would
be as appraised or sufficient to satisfy in full payments due on the Equipment
Notes issued thereunder or the Certificates.
 
DELIVERIES OF AIRCRAFT
 
     The Aircraft were originally scheduled for delivery under America West's
purchase agreement with AVSA from October 1998 to August 1999. See the table
under "-- The Appraisals" for the scheduled month of delivery of each Aircraft.
Under such purchase agreement, delivery of an Aircraft may be delayed due to
excusable delay, which is defined to include, among other things, acts of God,
governmental acts or failures to act, strikes or other labor troubles, inability
to procure materials, or any other cause beyond AVSA's control or not occasioned
by AVSA's fault or negligence.
 
     The Note Purchase Agreement provides that the Delivery Period will expire
on November 30, 1999, subject to extension, in the event that the Equipment
Notes relating to all of the Aircraft (or Substitute Aircraft in lieu thereof)
have not been purchased by the Trustees on or prior to such date due to any
reason beyond the control of America West and not occasioned by America West's
fault or negligence, to
 
                                       66
<PAGE>   68
 
the earlier of the purchase by the trustees of Equipment Notes relating to the
last Aircraft (or a Substitute Aircraft in lieu thereof) and January 31, 2000.
 
     If delivery of any Aircraft is delayed by more than 30 days after the month
scheduled for delivery, America West has the right to replace such Aircraft with
a Substitute Aircraft, subject to certain conditions. See "-- Substitute
Aircraft". If delivery of any Aircraft is delayed beyond the Delivery Period
Termination Date and America West does not exercise its right to replace such
Aircraft with a Substitute Aircraft, there will be unused Deposits that will be
distributed to Certificateholders together with accrued and unpaid interest
thereon and a premium, if applicable. See "Description of the Deposit
Agreements -- Unused Deposits".
 
SUBSTITUTE AIRCRAFT
 
     If the delivery date for any Aircraft is delayed more than 30 days after
the month scheduled for delivery, America West may identify for delivery a
Substitute Aircraft therefor meeting the following conditions:
 
        Conditions Required of a Substitute Aircraft
 
        (1) A Substitute Aircraft must be an Airbus A319-100 or A320-200
            aircraft manufactured after the Issuance Date.
 
        (2) One or more Substitute Aircraft of the same or different types may
            be substituted for one or more Aircraft of the same or different
            types so long as after giving effect thereto such substitution does
            not vary the Mandatory Economic Terms in respect of the replaced
            Aircraft.
 
        (3) America West will be obligated to obtain written confirmation from
            each Rating Agency that substituting such Substitute Aircraft for
            the replaced Aircraft will not result in a withdrawal, suspension or
            downgrading of the ratings of any Class of Certificates.
 
BRIDGE FINANCING
 
     America West may, pursuant to the Note Purchase Agreement, initially take
delivery of an Aircraft using bridge financing. Such bridge financing would be
utilized, for example, if America West has not finalized arrangements with an
Owner Participant in connection with a leveraged lease financing. Such bridge
financing would be paid, and any lien on the bridge financed Aircraft
extinguished, within 90 days of delivery of such Aircraft and prior to the
financing of such Aircraft pursuant to the Note Purchase Agreement.
 
                       DESCRIPTION OF THE EQUIPMENT NOTES
 
     The statements under this caption are summaries and do not purport to be
complete. The summaries make use of terms defined in and are qualified in their
entirety by reference to all of the provisions of the Equipment Notes, the
Indentures, the Leases, the Participation Agreements, the Trust Agreements and
the Note Purchase Agreement. Except as otherwise indicated, the following
summaries relate to the Equipment Notes, the Indenture, the Lease, the
Participation Agreement, and the Trust Agreement that may be applicable to each
Aircraft, forms of which are filed as exhibits to the Registration Statement and
are available as set forth under the heading "Available Information".
 
     Under the Note Purchase Agreement, America West will have the option of
entering into a leveraged lease financing or a debt financing with respect to
each Aircraft. The Note Purchase Agreement provides for the relevant parties to
enter into, with respect to each Leased Aircraft, a Participation Agreement, a
Lease and an Indenture (among other documents) relating to the financing of such
Aircraft or, with respect to each Owned Aircraft, a Participation Agreement and
an Owned Aircraft Indenture relating to the financing of such Owned Aircraft.
The description of such agreements in this Prospectus is based on
 
                                       67
<PAGE>   69
 
the forms of such agreements annexed to the Note Purchase Agreement. Requests
for the Note Purchase Agreement, including the forms of such agreements annexed
thereto, should be addressed to the Trustees.
 
     In the case of any leveraged lease financing of any Aircraft, America West
will select an Owner Participant for such Aircraft. Such Owner Participant may
request revisions to the forms of the Participation Agreement, the Lease and the
Leased Aircraft Indenture that are contemplated by the Note Purchase Agreement,
so that the terms of such agreements applicable to any particular Leased
Aircraft may differ from the description of such agreements contained in this
Prospectus. In the case of the financing of Aircraft where America West has
elected to issue Series D Equipment Notes and to fund the sale of such Series D
Equipment Notes through the sale of Series D Certificates, America West may
select purchasers of Series D Certificates. Such Class D Certificate purchasers
may request revisions to the Leased Aircraft Documents, in the case of a Leased
Aircraft, or to the forms of Participation Agreement and Owned Aircraft
Indenture, in the case of an Owned Aircraft, that are, in either case,
contemplated by the Note Purchase Agreement, so that the terms of such
agreements applicable to any particular Leased Aircraft or Owned Aircraft, as
the case may be, may differ from the description of such agreements contained in
this Prospectus. However, under the Note Purchase Agreement, the terms of such
agreements are required to contain the Mandatory Documents Terms and not vary
the Mandatory Economic Terms. In addition, America West is obligated to certify
to the Trustees that any such modifications do not materially and adversely
affect the Certificateholders and to obtain written confirmation from each
Rating Agency that the use of versions of such agreements modified in any
material respect would not result in a withdrawal, suspension or downgrading of
the ratings of any Class of Certificates. See "Description of the New
Certificates -- Obligation to Purchase Equipment Notes".
 
GENERAL
 
     The Equipment Notes will be issued in three series with respect to each
Aircraft (or, in certain circumstances for any Aircraft, four series for such
Aircraft). The Equipment Notes with respect to each Leased Aircraft will be
issued under a separate Leased Aircraft Indenture between State Street Bank and
Trust Company of Connecticut, N.A., as Owner Trustee of a trust for the benefit
of the Owner Participant who will be the beneficial owner of such Aircraft, and
Wilmington Trust Company, as Leased Aircraft Trustee. The Equipment Notes with
respect to each Owned Aircraft will be issued under a separate Owned Aircraft
Indenture between America West and Wilmington Trust Company, as Owned Aircraft
Trustee.
 
     In the case of any Leased Aircraft, the related Owner Trustee will lease
such Leased Aircraft to America West pursuant to a separate Lease between such
Owner Trustee and America West with respect to such Leased Aircraft. Under each
Lease, America West will be obligated to make or cause to be made rental and
other payments to the related Leased Aircraft Trustee on behalf of the related
Owner Trustee, which rental and other payments will be at least sufficient to
pay in full when due all payments required to be made on the Equipment Notes
issued with respect to such Leased Aircraft. The Equipment Notes issued with
respect to the Leased Aircraft are not, however, direct obligations of, or
guaranteed by, America West. America West's rental obligations under each Lease
and America West's obligations under the Equipment Notes issued with respect to
each Owned Aircraft will be general obligations of America West.
 
     In certain circumstances described below in "-- The Leases and Certain
Provisions of the Owned Aircraft Indentures -- Renewal and Purchase Options",
America West will have the right to purchase an Owner Trustee's right, title and
interest in and to the related Aircraft and to assume the related Leased
Aircraft Equipment Notes on a full recourse basis, subject to certain
conditions, which would reflect a financing contemplated by an Owned Aircraft
Indenture. In the event of such an assumption, America West will either furnish
an opinion to the relevant Leased Aircraft Trustee that such assumption does not
result in a taxable gain or loss for the Certificateholder for U.S. federal tax
purposes or an indemnity for the benefit of the Certificateholders in form and
substance reasonably satisfactory to the relevant Leased Aircraft Trustee.
 
                                       68
<PAGE>   70
 
SUBORDINATION
 
     Series B Equipment Notes issued in respect of any Aircraft will be
subordinated in right of payment to Series A Equipment Notes issued in respect
of such Aircraft; Series C Equipment Notes issued in respect of such Aircraft
will be subordinated in right of payment to such Series B Equipment Notes; and,
if America West elects to issue Series D Equipment Notes, they will be
subordinated in right of payment to the Series C Equipment Notes issued with
respect to such Aircraft. On each Equipment Note payment date, payments of
interest and principal due on Series A Equipment Notes issued in respect of any
Aircraft will be made prior to payments of interest and principal due on Series
B Equipment Notes issued in respect of such Aircraft; payments of interest and
principal due on Series B Equipment Notes issued in respect of any Aircraft will
be made prior to payments of interest and principal due on Series C Equipment
Notes issued in respect of such Aircraft; and if America West elects to issue
Series D Equipment Notes, payments of interest and principal due on such Series
C Equipment Notes will be made prior to payments of interest and principal due
on Series D Equipment Notes issued in respect of such Aircraft.
 
PRINCIPAL AND INTEREST PAYMENTS
 
     Subject to the provisions of the Intercreditor Agreement, interest paid on
the Equipment Notes held in each Trust will be passed through to the
Certificateholders of such Trust on the dates and at the rate per annum set
forth on the cover page of this Prospectus with respect to Certificates issued
by such Trust (subject to change as provided in the Registration Rights
Agreement) until the final expected Regular Distribution Date for such Trust.
Subject to the provisions of the Intercreditor Agreement, principal paid on the
Equipment Notes held in each Trust will be passed through to the
Certificateholders of such Trust in scheduled amounts on the dates set forth
herein until the final expected Regular Distribution Date for such Trust.
 
     Interest is payable on the unpaid principal amount of each Equipment Note
at the rate applicable to such Equipment Note on January 2 and July 2 in each
year, commencing on January 2, 1999, or, if later, the first such date to occur
after initial issuance thereof. Such interest is computed on the basis of a 360-
day year of twelve 30-day months. Under certain circumstances described in "The
Exchange Offer -- General", the interest rates for the Equipment Notes may be
increased to the extent described therein.
 
     Scheduled principal payments on the Equipment Notes will be made on January
2 and July 2 in certain years, commencing January 2, 1999. See "Description of
the New Certificates -- Pool Factors" for a discussion of the scheduled payments
of principal of the Equipment Notes and possible revisions thereto.
 
     If any date scheduled for any payment of principal, premium (if any) or
interest with respect to the Equipment Notes is not a Business Day, such payment
will be made on the next succeeding Business Day without any additional
interest.
 
REDEMPTION
 
     Event of Loss
 
     If an Event of Loss occurs with respect to any Aircraft and such Aircraft
is not replaced by America West under the related Lease (in the case of a Leased
Aircraft) or under the related Owned Aircraft Indenture (in the case of an Owned
Aircraft), the Equipment Notes issued with respect to such Aircraft will be
redeemed, in whole, in each case at a price equal to the aggregate unpaid
principal amount thereof, together with accrued interest thereon to, but not
including, the date of redemption, but without premium, on a Special
Distribution Date. (Indentures, Section 2.10(a))
 
     America West Optional Redemptions
 
     If America West exercises its right to terminate a Lease under Section 9 of
such Lease because the related Aircraft has become obsolete or surplus to the
Company's needs, the Equipment Notes relating to such Aircraft will be redeemed,
in whole, on a Special Distribution Date at a price equal to the aggregate
 
                                       69
<PAGE>   71
 
unpaid principal amount thereof, together with accrued interest thereon to, but
not including, the date of redemption, plus a Make-Whole Premium. (Leased
Aircraft Indentures, Section 2.10(b)). See "-- The Leases and Certain Provisions
of the Owned Aircraft Indentures -- Lease Termination".
 
     All of the Equipment Notes issued with respect to a Leased Aircraft may be
redeemed prior to maturity as part of a refunding or refinancing thereof under
Section 11 of the applicable Participation Agreement, and all of the Equipment
Notes issued with respect to the Owned Aircraft may be redeemed prior to
maturity at any time at the option of America West, in each case at a price
equal to the aggregate unpaid principal thereof, together with accrued interest
thereon to, but not including, the date of redemption, plus, in the case of any
series of Equipment Notes, a Make-Whole Premium. (Indentures, Section 2.11) If
notice of such a redemption shall have been given in connection with a
refinancing of Equipment Notes with respect to a Leased Aircraft, such notice
may be revoked not later than three days prior to the proposed redemption date.
(Leased Aircraft Indentures, Section 2.12)
 
     In addition, under certain Leases all of the Equipment Notes issued with
respect to such Leases may be redeemed prior to maturity with a Make-Whole
Premium on a Special Distribution Date in connection with America West's
exercise of certain options or elections relating to the purchase of the
Aircraft subject to such Leases under certain circumstances. See "-- The Leases
and Certain Provisions of the Owned Aircraft Indentures -- Renewal and Purchase
Options".
 
     Redemption Right in Favor of Owner Trustees or Owner Participant
 
     If, with respect to a Leased Aircraft, certain events listed below occur,
then, in each case all, but not less than all, of the Equipment Notes issued
with respect to such Leased Aircraft may be purchased by the Owner Trustee or
Owner Participant on the applicable purchase date at a price equal to the
aggregate unpaid principal thereof, together with accrued and unpaid interest
thereon to, but not including, the date of purchase, but without any premium
(provided that a Make-Whole Premium shall be payable if such Equipment Notes are
to be purchased pursuant to clause (1) below when a Lease Event of Default shall
have occurred and been continuing for fewer than 180 days). (Leased Aircraft
Indentures, Section 2.13)
 
        Events Triggering Right to Redemption
 
        (1) One or more Lease Events of Default shall have occurred and be
            continuing.
 
        (2) In the event of a bankruptcy proceeding involving America West (a)
            during the Section 1110 Period, the trustee in such proceeding or
            America West does not agree to perform its obligations under the
            related Lease or (b) at any time after agreeing to perform such
            obligations, such trustee or America West ceases to perform such
            obligations such that the stay period applicable under the U.S.
            Bankruptcy Code comes to an end.
 
        (3) The Equipment Notes with respect to such Aircraft have been
            accelerated or the Leased Aircraft Trustee with respect to such
            Equipment Notes takes action or notifies the applicable Owner
            Trustee that it intends to take action to foreclose the lien of the
            related Leased Aircraft Indenture or otherwise commence the exercise
            of any significant remedy under such Indenture or the related Lease.
 
     America West as owner of the Owned Aircraft has no comparable right under
the Owned Aircraft Indentures to purchase the Equipment Notes under such
circumstances.
 
                                       70
<PAGE>   72
 
     Certain Definitions
 
     "Make-Whole Premium" means, with respect to any Equipment Note, an amount
(as determined by an independent investment banker of national standing selected
by America West) equal to the excess, if any, determined under the following
calculation:
 
        Calculation of Make-Whole Premium
 
        (1) The present value of the remaining scheduled payments of principal
            and interest to maturity of such Equipment Note computed by
            discounting such payments on a semiannual basis on each Payment Date
            (assuming a 360-day year of twelve 30-day months) using a discount
            rate equal to the Treasury Yield, minus
 
        (2) the outstanding principal amount of such Equipment Note plus accrued
            interest to the date of determination.
 
     For purposes of determining the Make-Whole Premium, "Treasury Yield" means,
at the date of determination with respect to any Equipment Note, the interest
rate (expressed as a decimal and, in the case of United States Treasury bills,
converted to a bond equivalent yield) determined to be the per annum rate equal
to the semiannual yield to maturity for United States Treasury securities
maturing on the Average Life Date of such Equipment Note and trading in the
public securities markets either as determined by interpolation between the most
recent weekly average yield to maturity for two series of United States Treasury
securities trading in the public securities markets, (i) one maturing as close
as possible to, but earlier than, the Average Life Date of such Equipment Note
and (ii) the other maturing as close as possible to, but later than, the Average
Life Date of such Equipment Note, in each case as published in the most recent
H.15(519) or, if a weekly average yield to maturity for United States Treasury
securities maturing on the Average Life Date of such Equipment Note is reported
in the most recent H.15(519), such weekly average yield to maturity as published
in such H.15(519). "H.15(519)" means the weekly statistical release designated
as such, or any successor publication, published by the Board of Governors of
the Federal Reserve System. The date of determination of a Make-Whole Premium
shall be the third Business Day prior to the applicable payment or redemption
date and the "most recent H.15(519)" means the H.15(519) published prior to the
close of business on the third Business Day prior to the applicable payment or
redemption date.
 
     "Average Life Date" for any Equipment Note shall be the date which follows
the time of determination by a period equal to the Remaining Weighted Average
Life of such Equipment Note. "Remaining Weighted Average Life" on a given date
with respect to any Equipment Note shall be the number of days equal to the
quotient obtained under the following calculation:
 
        Calculation of Remaining Weighted Average Life
 
        (1) Divide the sum of each of the products obtained by multiplying
 
            (a) the amount of each then remaining scheduled payment of principal
                of such Equipment Note, by
 
            (b) the number of days from and including such determination date to
                but excluding the date on which such payment of principal is
                scheduled to be made, by
 
        (2) the then outstanding principal amount of such Equipment Note.
 
                                       71
<PAGE>   73
 
SECURITY
 
     The Equipment Notes issued with respect to each Leased Aircraft will be
secured by all of the following items:
 
        Security for the Equipment Notes
 
        (1) An assignment by the related Owner Trustee to the related Leased
            Aircraft Trustee of such Owner Trustee's rights, except for certain
            limited rights, under the Lease with respect to the related
            Aircraft, including the right to receive payments of rent
            thereunder.
 
        (2) A mortgage to such Leased Aircraft Trustee of such Aircraft, subject
            to the rights of America West under such Lease.
 
        (3) An assignment to such Leased Aircraft Trustee of certain of such
            Owner Trustee's rights under the purchase agreement between America
            West and the related manufacturer.
 
     Prior to an Indenture Default, the Owner Participant in respect of any
Leased Aircraft will have the right, to the exclusion of the related Loan
Trustee, to approve as satisfactory counsel furnishing legal opinions,
appraisers and accountants. Also, such Owner Participant will have the right, to
the exclusion of the related Loan Trustee, to approve the identity of permitted
sublessees (not otherwise permitted by the related Lease), and to approve the
form of the bill of sale required for the substitution of Aircraft following an
event of loss thereof.
 
     Unless and until the related Leased Aircraft Trustee has foreclosed upon
the Lien of the related Leased Aircraft Indenture, the Leased Aircraft Trustee
may not exercise the balance of the rights of the Owner Trustee under the
related Lease (such as the amendment or modification of such Lease) without the
concurrence of such Owner Trustee. However, in all instances, the right of the
Leased Aircraft Trustee to exercise remedies under Section 15 of the related
Lease are rights exclusive to the Leased Aircraft Trustee. The assignment by the
Owner Trustee to the Leased Aircraft Trustee of its rights under the related
Lease will also exclude certain rights of such Owner Trustee and the related
Owner Participant to receive indemnification by America West for certain
matters, insurance proceeds payable to such Owner Trustee in its individual
capacity or to such Owner Participant under public liability insurance
maintained by America West under such Lease or by such Owner Trustee or such
Owner Participant, insurance proceeds payable to such Owner Trustee in its
individual capacity or to such Owner Participant under certain casualty
insurance maintained by such Owner Trustee or such Owner Participant under such
Lease and certain reimbursement payments made by America West to such Owner
Trustee. (Leased Aircraft Indenture, Granting Clause and Section 5.02) The
Equipment Notes are not cross-collateralized, and, consequently, the Equipment
Notes issued in respect of any one Aircraft are not secured by any of the other
Aircraft or replacement aircraft therefor (as described in "-- The Leases and
Certain Provisions of the Owned Aircraft Indentures -- Events of Loss") or the
Leases related thereto.
 
     The Equipment Notes issued with respect to each Owned Aircraft are secured
by a mortgage to the Owned Aircraft Trustee of such Aircraft and an assignment
to the Owned Aircraft Trustee of certain of America West's rights under its
purchase agreement with the related manufacturer.
 
     Funds, if any, held from time to time by the Loan Trustee with respect to
any Aircraft, including funds held as the result of an Event of Loss to such
Aircraft or, in the case of a Leased Aircraft, termination of the Lease, if any,
relating thereto, will be invested and reinvested by such Loan Trustee, at the
direction of America West (except in the case of certain Indenture Defaults), in
investments described in the related Indenture. (Indentures, Section 5.09)
 
                                       72
<PAGE>   74
 
EQUIPMENT NOTES AND THE AIRCRAFT
 
     Set forth below is certain information about the Equipment Notes expected
to be held in the Trusts and the Aircraft expected to secure such Equipment
Notes:
 
<TABLE>
<CAPTION>
                                                                                  MAXIMUM
                                                                                 PRINCIPAL
                         EXPECTED         EXPECTED                               AMOUNT OF
                       REGISTRATION    MANUFACTURER'S    AIRCRAFT DELIVERY       EQUIPMENT         APPRAISED
AIRCRAFT TYPE             NUMBER       SERIAL NUMBER         MONTH(1)             NOTES(2)         VALUE(3)
- ---------------------  ------------    --------------    -----------------    ----------------    -----------
<S>                    <C>             <C>               <C>                  <C>                 <C>
Airbus A319-132           N801AW             889          October 1998          $22,064,000       $36,380,000
Airbus A319-132           N802AW             924          December 1998          22,064,000        36,413,333
Airbus A319-132           N803AW             931          December 1998          22,064,000        36,413,333
Airbus A319-132           N804AW            1049            July 1999            22,064,000        37,793,333
Airbus A319-132           N805AW            1056            July 1999            22,064,000        37,793,333
Airbus A319-132           N806AW            1071           August 1999           22,064,000        37,826,667
Airbus A320-232           N652AW             953          February 1999          28,717,800        43,196,667
Airbus A320-232           N653AW            1003            May 1999             29,427,200        43,573,333
</TABLE>
 
- -------------------------
 
     (1) Reflects the originally scheduled delivery months under America West's
         purchase agreement with the manufacturer. The actual delivery date for
         any Aircraft may be subject to change. The delivery month for Aircraft
         N806AW has been changed to July 1999. See "Description of the Aircraft
         and the Appraisals -- Deliveries of Aircraft". America West has the
         option to substitute other Airbus A319-100 or A320-200 aircraft in the
         event that the delivery of any Aircraft is expected to be delayed for
         more than 30 days after the month scheduled for delivery or beyond the
         Delivery Period Termination Date. See "Description of the Aircraft and
         the Appraisals -- Substitute Aircraft". Aircraft N801AW, N802AW and
         N803AW were delivered by the manufacturer on October 8, 1998, December
         10, 1998 and December 17, 1998, respectively and subject to a leveraged
         lease financing utilizing Equipment Notes on November 20, 1998,
         December 15, 1998 and December 22, 1998, respectively.
 
     (2) Reflects the initial maximum principal amount as of the date of
         original issuance, which principal amount may be less with respect to
         an Aircraft depending on the circumstances of the financing of such
         Aircraft. The aggregate principal amount of all of the Equipment Notes
         will not exceed the aggregate face amount of the Certificates. The
         aggregate principal amount of Equipment Notes utilized for Aircraft
         N801AW, N802AW and N803AW were $21,531,592.07, $21,627,551.78 and
         $21,640,169.05, respectively.
 
     (3) The appraised value of each Aircraft set forth above is based upon
         varying assumptions and methodologies and reflects the lesser of the
         average and median values of such aircraft as appraised by the
         Appraisers, determined as of September 24, 1998, and projected as of
         the scheduled delivery month of each Aircraft. An appraisal is only an
         estimate of value and should not be relied upon as a measure of
         realizable value. The proceeds realized upon a sale of any Aircraft may
         be less than the appraised value thereof. In addition, the value of the
         Aircraft in the event of the exercise of remedies under the applicable
         Indenture will depend on market and economic conditions, the
         availability of buyers, the condition of the Aircraft, whether the
         Aircraft are sold separately or as a block and other factors.
         Accordingly, there can be no assurance that the proceeds realized upon
         any such exercise with respect to the Equipment Notes and the Aircraft
         pursuant to the applicable Indenture would be sufficient to satisfy in
         full payments due on the Equipment Notes issued thereunder or the
         Certificates. See "Risk Factors -- Risk Factors Relating to the
         Certificates and the Offering -- Appraisals and Realizable Value of
         Aircraft" and "Description of the Aircraft and the Appraisals".
 
                                       73
<PAGE>   75
 
LOAN TO VALUE RATIOS OF EQUIPMENT NOTES
 
     The following tables set forth examples of loan to Aircraft value ratios
for the Equipment Notes issued in respect of Aircraft as of the Regular
Distribution Dates that occur after the scheduled date of original issuance of
such Equipment Notes. These examples were utilized by America West in preparing
the Assumed Amortization Schedule, although such schedule may not be applicable
in the case of any particular Aircraft. See "Description of the New
Certificates -- Pool Factors". The LTV was obtained by dividing the outstanding
balance (assuming no payment default) of such Equipment Notes determined
immediately after giving effect to the payments scheduled to be made on each
such Regular Distribution Date by the assumed value (the "Assumed Aircraft
Value") of the Aircraft securing such Equipment Notes.
 
     The following tables are based on the assumption (the "Depreciation
Assumption") that the value of each Aircraft set forth opposite the initial
Regular Distribution Date included in each table depreciates by approximately 3%
of the initial appraised value per year until the 15th year after the year of
delivery of such Aircraft and by approximately 4% of the initial appraised value
per year thereafter. Other rates or methods of depreciation would result in
materially different loan to Aircraft value ratios, and no assurance can be
given that the depreciation rates and method assumed for the purposes of the
tables are the ones most likely to occur or as to the actual future value of any
Aircraft. Thus the tables should not be considered a forecast or prediction of
expected or likely loan to Aircraft value ratios, but simply a mathematical
calculation based on one set of assumptions.
 
<TABLE>
<CAPTION>
                                         AIRBUS A319-132                           AIRBUS A320-232
                             ---------------------------------------   ---------------------------------------
                              EQUIPMENT                                 EQUIPMENT
                                NOTE        ASSUMED                       NOTE        ASSUMED
                             OUTSTANDING    AIRCRAFT      LOAN TO      OUTSTANDING    AIRCRAFT      LOAN TO
DATE                           BALANCE       VALUE      VALUE RATIO      BALANCE       VALUE      VALUE RATIO
- ----                         -----------    --------    ------------   -----------    --------    -----------
                             (MILLIONS)    (MILLIONS)                  (MILLIONS)    (MILLIONS)
<S>                          <C>           <C>          <C>            <C>           <C>          <C>
January 2, 2000...........     $21.82        $37.70         57.9%        $27.74        $43.57         63.7%
January 2, 2001...........      21.29         36.66         58.1          26.61         42.27         63.0
January 2, 2002...........      20.70         35.53         58.3          25.70         40.96         62.7
January 2, 2003...........      19.97         34.39         58.1          24.85         39.65         62.7
January 2, 2004...........      18.71         33.26         56.3          23.83         38.34         62.1
January 2, 2005...........      18.17         32.12         56.5          22.73         37.04         61.4
January 2, 2006...........      17.62         30.99         56.9          21.50         35.73         60.2
January 2, 2007...........      17.14         29.86         57.4          20.23         34.42         58.8
January 2, 2008...........      16.37         28.72         57.0          19.23         33.12         58.1
January 2, 2009...........      15.48         27.59         56.1          18.22         31.81         57.3
January 2, 2010...........      14.12         26.46         53.4          16.64         30.50         54.6
January 2, 2011...........      11.53         25.32         45.6          15.19         29.19         52.0
January 2, 2012...........       9.80         24.19         40.5          13.57         27.89         48.7
January 2, 2013...........       7.95         23.05         34.5          11.07         26.58         41.7
January 2, 2014...........       5.96         21.92         27.2           8.39         25.27         33.2
January 2, 2015...........       3.83         20.79         18.4           5.53         23.97         23.1
January 2, 2016...........       1.55         19.27          8.1           2.46         22.22         11.1
January 2, 2017...........       0.00          0.00           NA           0.00          0.00           NA
</TABLE>
 
LIMITATION OF LIABILITY
 
     The Equipment Notes issued with respect to the Leased Aircraft are not
direct obligations of, or guaranteed by, America West, any Owner Participant or
any Owner Trustee in its individual capacity. None of the Owner Trustees, the
Owner Participants or the Leased Aircraft Trustees, or any affiliates thereof,
will be personally liable to any holder of an Equipment Note or, in the case of
the Owner Trustees and the Owner Participants, to the Leased Aircraft Trustees
for any amounts payable under the
 
                                       74
<PAGE>   76
 
Equipment Notes or, except as provided in each Leased Aircraft Indenture, for
any liability under such Leased Aircraft Indenture. All payments of principal
of, premium, if any, and interest on the Equipment Notes issued with respect to
any Leased Aircraft (other than payments made in connection with an optional
redemption or purchase of Equipment Notes issued with respect to a Leased
Aircraft by the related Owner Trustee or the related Owner Participant or the
election by an Owner Trustee to retain title to an Aircraft subject to a
termination for obsolescence) will be made only from the assets subject to the
lien of the Indenture with respect to such Leased Aircraft or the income and
proceeds received by the related Leased Aircraft Trustee therefrom (including
rent payable by America West under the Lease with respect to such Leased
Aircraft).
 
     The Equipment Notes issued with respect to the Owned Aircraft will be
direct obligations of America West.
 
     Except as otherwise provided in the Indentures, each Owner Trustee and each
Loan Trustee, in its individual capacity, will not be answerable or accountable
under the Indentures or under the Equipment Notes under any circumstances except
for its own willful misconduct or gross negligence. None of the Owner
Participants will have any duty or responsibility under any of the Leased
Aircraft Indentures or the Equipment Notes to the Leased Aircraft Trustees or to
any holder of any Equipment Note.
 
INDENTURE DEFAULTS, NOTICE AND WAIVER
 
     A list of Indenture Defaults is set forth below:
 
        Indenture Defaults
 
        (1) In the case of a Leased Aircraft Indenture, the occurrence of any
            Lease Event of Default under the related Lease.
 
        (2) The failure by the related Owner Trustee (other than as a result of
            a Lease Default or Lease Event of Default), in the case of a Leased
            Aircraft Indenture, or America West, in the case of an Owned
            Aircraft Indenture, to pay any interest or principal or premium, if
            any, when due, under such Indenture or under any Equipment Note
            issued thereunder that continues for more than ten Business Days, in
            the case of principal, interest or Make-Whole Premium, and, in all
            other cases, 30 days after the relevant Owner Trustee or Owner
            Participant, or America West, receives written demand from the
            related Loan Trustee or holder of an Equipment Note.
 
        (3) The failure by the related Owner Participant or the related Owner
            Trustee (in its individual capacity), in the case of a Leased
            Aircraft Indenture, or America West, in the case of an Owned
            Aircraft Indenture, to discharge certain liens that continues after
            notice and specified cure periods.
 
        (4) Any representation or warranty made by the related Owner Trustee or
            Owner Participant in the related Operative Agreements, or certain
            related documents furnished to the Loan Trustee pursuant thereto
            being false or incorrect in any material respect when made that
            continues to be material and adverse to the interests of the Loan
            Trustee or Note Holders and remains unremedied after notice and
            specified cure periods.
 
        (5) Failure by America West or the related Owner Trustee or Owner
            Participant to perform or observe any covenant or obligation for the
            benefit of the Loan Trustee or holders of Equipment Notes under such
            Indenture or certain related documents that continues after notice
            and specified cure periods.
 
        (6) The registration of the related Aircraft ceasing to be effective as
            a result of the Owner Participant (in the case of a Leased Aircraft)
            or America West (in the case of an Owned Aircraft) not being a
            citizen of the United States, as defined in the Transportation Code
            (subject to a cure period).
 
                                       75
<PAGE>   77
 
        (7) With respect to the Owned Aircraft, the lapse or cancellation of
            insurance required under the Owned Aircraft Indenture.
 
        (8) The occurrence of certain events of bankruptcy, reorganization or
            insolvency of the related Owner Trustee or Owner Participant (in the
            case of a Leased Aircraft) or America West (in the case of the Owned
            Aircraft). (Leased Aircraft Indentures, Section 4.02; Owned Aircraft
            Indentures, Section 5.01)
 
There will not be cross-default provisions in the Indentures or in the Leases
(unless, in the case of a Lease, otherwise agreed between an Owner Participant
and America West). Consequently, events resulting in an Indenture Default under
any particular Indenture may or may not result in an Indenture Default occurring
under any other Indenture, and a Lease Event of Default under any particular
Lease may or may not constitute a Lease Event of Default under any other Lease.
 
     Equity Cure Rights
 
     If America West fails to make any semiannual basic rental payment due under
any Lease, within a specified period after such failure the applicable Owner
Trustee may furnish to the Leased Aircraft Trustee the amount due on the
Equipment Notes issued with respect to the related Leased Aircraft, together
with any interest thereon on account of the delayed payment thereof, in which
event the Leased Aircraft Trustee and the holders of outstanding Equipment Notes
issued under such Indenture may not exercise any remedies otherwise available
under such Indenture or such Lease as the result of such failure to make such
rental payment, unless such Owner Trustee has previously cured three or more
immediately preceding semiannual basic rental payment defaults or, in total, six
or more previous semiannual basic rental payment defaults. The applicable Owner
Trustee also may cure any other default by America West in the performance of
its obligations under any Lease that can be cured with the payment of money.
(Leased Aircraft Indentures, Section 4.03)
 
     The holders of a majority in principal amount of the outstanding Equipment
Notes issued with respect to any Aircraft, by notice to the Loan Trustee, may on
behalf of all the holders waive any existing default and its consequences under
the Indenture with respect to such Aircraft, except a default in the payment of
the principal of, or premium or interest on any such Equipment Notes or a
default in respect of any covenant or provision of such Indenture that cannot be
modified or amended without the consent of each holder of Equipment Notes
affected thereby. (Leased Aircraft Indentures, Section 4.08; Owned Aircraft
Indentures, Section 5.06)
 
REMEDIES
 
     If an Indenture Default occurs and is continuing under an Indenture, the
related Loan Trustee or the holders of a majority in principal amount of the
Equipment Notes outstanding under such Indenture may, subject to the applicable
Owner Participant's or Owner Trustee's right to cure, as discussed above,
declare the principal of all such Equipment Notes issued thereunder immediately
due and payable, together with all accrued but unpaid interest thereon, provided
that in the event of a reorganization proceeding involving America West
instituted under Chapter 11 of the U.S. Bankruptcy Code, if no other Lease Event
of Default and no other Indenture Default (other than the failure to pay the
outstanding amount of the Equipment Notes which by such declaration shall have
become payable) exists at any time after the consummation of such proceeding,
such declaration will be automatically rescinded without any further action on
the part of any holder of Equipment Notes. The holders of a majority in
principal amount of Equipment Notes outstanding under such Indenture may rescind
any such declaration at any time before the judgment or decree for the payment
of the money so due shall be entered if there has been paid to the related Loan
Trustee an amount sufficient to pay all principal, interest, and premium, if
any, on any such Equipment Notes, to the extent such amounts have become due
otherwise than by such declaration of acceleration and all other Indenture
Defaults and incipient Indenture Defaults under such Indenture have been cured.
(Leased Aircraft Indentures, Section 4.04(b); Owned Aircraft Indentures, Section
5.02(b))
 
                                       76
<PAGE>   78
 
     Each Indenture provides that if an Indenture Default under such Indenture
has occurred and is continuing, the related Loan Trustee may exercise certain
rights or remedies available to it under such Indenture or under applicable law,
including, in the case of a Leased Aircraft, if the corresponding Lease has been
declared in default, one or more of the remedies under such Lease with respect
to the Aircraft subject to such Lease. In the case of a Leased Aircraft, if an
Indenture Default arises solely by reason of one or more events or circumstances
which constitute a Lease Event of Default, the related Leased Aircraft Trustee's
right to exercise remedies under a Leased Aircraft Indenture is subject, with
certain exceptions, to its having proceeded to exercise one or more of the
dispossessory remedies under the Lease with respect to such Leased Aircraft;
provided that the requirement to exercise one or more of such remedies under
such Lease shall not apply in circumstances where such exercise has been
involuntarily stayed or prohibited by applicable law or court order for a
continuous period in excess of 60 days or such other period as may be specified
in Section 1110(a)(1)(A) of the U.S. Bankruptcy Code (plus an additional period,
if any, resulting from (i) the trustee or debtor-in-possession in such
proceeding agreeing to perform its obligations under such Lease with the
approval of the applicable court and its continuous performance of such Lease
under Section 1110(a)(1)(A-B) of the U.S. Bankruptcy Code or such Leased
Aircraft Trustee' consent to an extension of such period, (ii) such Leased
Aircraft Trustee's failure to give any requisite notice, or (iii) America West's
assumption of such Lease with the approval of the relevant court and its
continuous performance of the Lease so assumed). See "-- The Leases and Certain
Provisions of the Owned Aircraft Indentures -- Events of Default Under the
Leases". Such remedies may be exercised by the related Leased Aircraft Trustee
to the exclusion of the related Owner Trustee, subject to certain conditions
specified in such Indenture, and of America West, subject to the terms of such
Lease. Any Aircraft sold in the exercise of such remedies will be free and clear
of any rights of those parties, including the rights of America West under the
Lease with respect to such Aircraft; provided that no exercise of any remedies
by the related Leased Aircraft Trustee may affect the rights of America West
under any Lease unless a Lease Event of Default has occurred and is continuing.
(Leased Aircraft Indentures, Section 4.04; Leases, Section 15) The Owned
Aircraft Indentures will not contain such limitations on the Owned Aircraft
Trustee's ability to exercise remedies upon an Indenture Default under an Owned
Aircraft Indenture.
 
     If the Equipment Notes issued in respect of one Aircraft are in default,
the Equipment Notes issued in respect of the other Aircraft may not be in
default, and, if not, no remedies will be exercisable under the applicable
Indentures with respect to such other Aircraft.
 
     Section 1110 of the U.S. Bankruptcy Code
 
     Section 1110 of the U.S. Bankruptcy Code provides that the right of
lessors, conditional vendors and holders of security interests with respect to
"equipment" (as defined in Section 1110 of the U.S. Bankruptcy Code) to take
possession of such equipment in compliance with the provisions of a lease,
conditional sale contract or security agreement, as the case may be, is not
affected by the following events:
 
        Events That Do Not Affects Rights with Respect to Equipment
 
        (1) The automatic stay provision of the U.S. Bankruptcy Code, which
            provision enjoins repossessions by creditors for the duration of the
            reorganization period.
 
        (2) The provision of the U.S. Bankruptcy Code allowing the trustee in
            reorganization to use property of the debtor during the
            reorganization period.
 
        (3) Section 1129 of the U.S. Bankruptcy Code (which governs the
            confirmation of plans of reorganization in Chapter 11 cases).
 
        (4) Any power of the bankruptcy court to enjoin a repossession.
 
Section 1110 provides, however, that the right of a lessor, conditional vendor
or holder of a security interest to take possession of an aircraft in the event
of an event of default may not be exercised for 60 days following the date of
commencement of the reorganization proceedings (unless specifically permitted by
the bankruptcy court) and may not be exercised at all if, within such 60-day
period (or such
                                       77
<PAGE>   79
 
longer period consented to by the lessor, conditional vendor or holder of a
security interest), the trustee in reorganization agrees to perform the debtor's
obligations that become due on or after such date and cures all existing
defaults (other than defaults resulting solely from the financial condition,
bankruptcy, insolvency or reorganization of the debtor). "Equipment" is defined
in Section 1110 of the U.S. Bankruptcy Code, in part, as "an aircraft, aircraft
engine, propeller, appliance, or spare part (as defined in section 40102 of
title 49 of the U.S. Code) that is subject to a security interest granted by,
leased to, or conditionally sold to a debtor that is a citizen of the United
States (as defined in section 40102 of title 49 of the U.S. Code) holding an air
carrier operating certificate issued by the Secretary of Transportation pursuant
to chapter 447 of title 49 of the U.S. Code for aircraft capable of carrying 10
or more individuals or 6,000 pounds or more of cargo".
 
     Opinion of America West Counsel
 
     It is a condition to the Trustee's obligation to purchase Equipment Notes
with respect to each Aircraft that outside counsel to America West, which is
expected to be Vedder, Price, Kaufman & Kammholz provide its opinion to the
Trustees that (1) if such Aircraft is a Leased Aircraft, the Owner Trustee, as
lessor under the Lease for such Aircraft, and the Leased Aircraft Trustee, as
assignee of such Owner Trustee's rights under such Lease pursuant to the related
Leased Aircraft Indenture, will be entitled to the benefits of Section 1110 of
the U.S. Bankruptcy Code with respect to the airframe and engines comprising
such Aircraft or (2) if such Aircraft is an Owned Aircraft, the Owned Aircraft
Trustee will be entitled to the benefits of Section 1110 with respect to the
airframe and engines comprising such Owned Aircraft, in each case so long as
America West continues to be a "citizen of the United States" as defined in
Section 40102 of title 49 of the U.S. Code holding an air carrier operating
certificate issued by the Secretary of Transportation pursuant to chapter 447 of
title 49 of the U.S. Code for aircraft capable of carrying 10 or more
individuals or 6,000 pounds or more of cargo. For a description of certain
limitations on the Loan Trustee's exercise of rights contained in the Indenture,
see "-- Indenture Defaults, Notice and Waiver".
 
     The opinion of Vedder, Price, Kaufman & Kammholz will not address the
possible replacement of an Aircraft after an Event of Loss in the future, the
consummation of which is conditioned upon the contemporaneous delivery of an
opinion of counsel to the effect that the related Loan Trustee will be entitled
to Section 1110 benefits with respect to such replacement unless there was,
subsequent to the delivery of such Aircraft, a change in law or court
interpretation that results in Section 1110 not being available. See "-- The
Leases -- Events of Loss". The opinion of Vedder, Price, Kaufman & Kammholz will
also not address the availability of Section 1110 with respect to any possible
sublessee of a Leased Aircraft subleased by America West or to any possible
lessee of an Owned Aircraft if it is leased by America West.
 
     A recent decision by the U.S. District Court for the District of Colorado
arising from the bankruptcy proceedings of Western Pacific Airlines, Inc. (Civil
Action No. 98-K-358) held that, once an airline debtor reaffirms its obligations
and cures its defaults under an aircraft lease within the prescribed period in
accordance with Section 1110 of the U.S. Bankruptcy Code, the lessor under such
lease is not entitled to repossess the aircraft under Section 1110 if the
airline subsequently defaults under such lease. The opinion of Vedder, Price,
Kaufman & Kammholz states that, in the firm's opinion, the District Court
holding is erroneous because it is inconsistent with the overriding purpose of
Section 1110 to protect lessors of, and creditors served by, qualifying aircraft
against being stayed from exercising their rights while defaults under their
leases or financing agreements remain uncured. Certain parties in the Western
Pacific case have appealed such decision.
 
     Reimbursement of Loan Trustee Expenses
 
     If an Indenture Default under any Indenture occurs and is continuing, any
sums held or received by the related Loan Trustee, subject to certain limited
exceptions, may be applied to reimburse such Loan Trustee for any tax, expense
or other loss incurred by it and to pay any other amounts due to such Loan
 
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<PAGE>   80
 
Trustee prior to any payments to holders of the Equipment Notes issued under
such Indenture. (Indentures, Sections 3.03 and 3.04)
 
     Bankruptcy or Like Proceedings of an Owner Participant
 
     In the event of bankruptcy, insolvency, receivership or like proceedings
involving an Owner Participant, it is possible that, notwithstanding that the
applicable Leased Aircraft is owned by the related Owner Trustee in trust, such
Leased Aircraft and the related Lease and Equipment Notes might become part of
such proceeding. In such event, payments under such Lease or on such Equipment
Notes might be interrupted and the ability of the related Leased Aircraft
Trustee to exercise its remedies under the related Leased Aircraft Indenture
might be restricted, although such Leased Aircraft Trustee would retain its
status as a secured creditor in respect of the related Lease and the related
Leased Aircraft.
 
MODIFICATION OF INDENTURES AND LEASES
 
     Without the consent of holders of a majority in principal amount of the
Equipment Notes outstanding under any Indenture, the provisions of such
Indenture and any related Lease, Participation Agreement or Trust Agreement may
not be amended or modified, except to the extent indicated below.
 
     Subject to certain limitations, certain provisions of any Leased Aircraft
Indenture, and of the Lease, the Participation Agreement, and the Trust
Agreement related thereto, may be amended or modified by the parties thereto
without the consent of any holders of the Equipment Notes outstanding under such
Indenture. In the case of each Lease, such provisions include, among others,
provisions relating to the return to the related Owner Trustee of the related
Leased Aircraft at the end of the term of such Lease (except to the extent that
such amendment would affect the rights or exercise of remedies under the Lease)
and the renewal of such Lease and the option of America West at the end of the
term of such Lease to purchase the related Leased Aircraft so long as the same
would not adversely affect the Note Holders. (Leased Aircraft Indentures,
Section 9.01(a)) In addition, any Indenture may be amended without the consent
of the holders of Equipment Notes to, among other things, cure any defect or
inconsistency in such Indenture or the Equipment Notes issued thereunder,
provided that such change does not adversely affect the interests of any such
holder. (Leased Aircraft Indentures, Section 9.01(c); Owned Aircraft Indentures,
Section 10.01)
 
     Without the consent of the holder of each Equipment Note outstanding under
any Indenture affected thereby, no amendment or modification of such Indenture
may among other things have the effect noted below:
 
        Amendments or Modifications of an Indenture Requiring Consent of Each
Holder of Equipment Notes
 
        (1) Reduce the principal amount of, or premium, if any, or interest
            payable on, any Equipment Notes issued under such Indenture or
            change the date on which any principal or premium, if any, or
            interest is due and payable.
 
        (2) Permit the creation of any security interest with respect to the
            property subject to the lien of such Indenture, except as provided
            in such Indenture, or deprive any holder of an Equipment Note issued
            under such Indenture of the benefit of the lien of such Indenture
            upon the property subject thereto.
 
        (3) Reduce the percentage in principal amount of outstanding Equipment
            Notes issued under such Indenture necessary to modify or amend any
            provision of such Indenture or to waive compliance therewith.
            (Leased Aircraft Indentures, Section 9.01(b); Owned Aircraft
            Indentures, Section 10.01(a))
 
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<PAGE>   81
 
INDEMNIFICATION
 
     America West will be required to indemnify each Loan Trustee, each Owner
Participant, each Owner Trustee, the Liquidity Provider, the Subordination
Agent, the Escrow Agent and each Trustee, but not the holders of Certificates,
for certain losses, claims and other matters. America West will be required
under certain circumstances to indemnify each Owner Participant against the loss
of depreciation deductions and certain other benefits allowable for certain
income tax purposes with respect to the related Leased Aircraft. Each Owner
Participant will be required to indemnify the related Loan Trustee and the
holders of the Equipment Notes issued with respect to the Leased Aircraft in
which such Owner Participant has an interest for certain losses that may be
suffered as a result of the failure of such Owner Participant to discharge
certain liens or claims on or against the assets subject to the lien of the
related Indenture.
 
THE LEASES AND CERTAIN PROVISIONS OF THE OWNED AIRCRAFT INDENTURES
 
     Each Leased Aircraft will be leased to America West by the relevant Owner
Trustee under the relevant lease agreement. Each Owned Aircraft will be owned by
America West.
 
     Lease Term Rentals and Payments
 
     Each Leased Aircraft will be leased separately by the relevant Owner
Trustee to America West for a term commencing on the date on which the Aircraft
is acquired by the Owner Trustee and expiring on a date not earlier than the
latest maturity date of the relevant Equipment Notes, unless terminated prior to
the originally scheduled expiration date as permitted by the applicable Lease.
The semiannual basic rent payment under each Lease is payable by America West on
each related Lease Payment Date (or, if such day is not a Business Day, on the
next Business Day), and will be assigned by the Owner Trustee under the
corresponding Leased Aircraft Indenture to provide the funds necessary to make
scheduled payments of principal and interest due from the Owner Trustee on the
Equipment Notes issued under such Indenture. In certain cases, the semiannual
basic rent payments under the Leases may be adjusted, but each Lease provides
that under no circumstances will rent payments by America West be less than the
scheduled payments on the related Equipment Notes. In addition, the amount of
basic rent will be increased in an amount necessary to pay additional interest
due on the Equipment Notes on the relevant Lease Payment Date as a result of any
increase in the rate of interest on the Equipment Notes as required by the terms
of the Registration Rights Agreement. Any balance of each such semiannual basic
rent payment under each Lease, after payment of amounts due on the Equipment
Notes issued under the Indenture corresponding to such Lease, will be paid over
to the Owner Trustee. (Leases, Section 3; Leased Aircraft Indentures, Section
3.01)
 
     "Lease Payment Date" means, with respect to each Lease, January 2 or July 2
during the term of such Lease.
 
     Semiannual payments of interest on the Equipment Notes issued by America
West under an Owned Aircraft Indenture are payable each January 2 and July 2
commencing on January 2, 1999 or, if later, the first such date after issuance
thereof. Semiannual payments of principal under the Equipment Notes issued by
America West under an Owned Aircraft Indenture are payable on January 2 and July
2 in certain years commencing on January 2, 1999. The amount of a semiannual
payment of interest or principal will be increased in an amount equal to any
increase in the amount of interest due on such Equipment Notes on the relevant
payment date as a result of any increase in the rate of interest on such
Equipment Notes as required by the terms of the Registration Rights Agreement.
 
     Net Lease; Maintenance
 
     America West is obligated under each Lease, among other things and at its
expense, to keep each Aircraft duly registered and insured, to pay all costs of
operating the Aircraft and to maintain, service, repair and overhaul the
Aircraft so as to keep it in as good an operating condition as when delivered to
America West, ordinary wear and tear excepted and without taking into
consideration hours and cycles, and in such condition as required to maintain
the airworthiness certificate for the Aircraft in good standing
                                       80
<PAGE>   82
 
at all times, subject to certain limited exceptions, including temporary storage
or maintenance periods and the grounding of similar aircraft by the applicable
aviation authority. (Leases, Sections 7.1 and 8.1 and Annexes C and D) The Owned
Aircraft Indenture imposes comparable maintenance, service and repair
obligations on America West with respect to the Owned Aircraft. (Owned Aircraft
Indentures, Section 4.02)
 
     Possession, Sublease and Transfer
 
     Each Aircraft may be operated by America West or, subject to certain
restrictions, by certain other persons. Normal interchange and pooling
agreements with respect to any Engine are permitted. Subleases, in the case of
Leased Aircraft, and leases, in the case of Owned Aircraft, are also permitted
to U.S. air carriers and foreign air carriers that have their principal
executive office in certain specified countries or, in the case of the Special
Agreements, that are listed in the applicable Lease, subject to a reasonably
satisfactory legal opinion that, among other things, such country would
recognize (in the case of the Leased Aircraft) Owner Trustee's title to, and the
Loan Trustee's lien in respect of, the applicable Aircraft. In addition, a
sublessee or lessee may not be subject to insolvency or similar proceedings at
the commencement of such sublease or lease. (Leases, Section 7, Owned Aircraft
Indentures, Section 4.02) Permitted foreign air carriers are not limited to
those based in a country that is a party to the Convention on the International
Recognition of Rights in Aircraft (Geneva 1948) (the "Convention"). It is
uncertain to what extent the relevant Loan Trustee's security interest would be
recognized if an Aircraft is registered or located in a jurisdiction not a party
to the Convention. Moreover, in the case of an Indenture Event of Default, the
ability of the related Loan Trustee to realize upon its security interest in an
Aircraft could be adversely affected as a legal or practical matter if such
Aircraft were registered or located outside the United States.
 
     Registration
 
     Subject to the next paragraph, America West is required to keep each
Aircraft duly registered under the Transportation Code with the FAA, except (in
the case of a Leased Aircraft) if the relevant Owner Trustee or the relevant
Owner Participant fails to meet the applicable citizenship requirements, and to
record each Lease (in the case of a Leased Aircraft, but subject to such
citizenship requirements) and Indenture and certain other documents under the
Transportation Code. (Leases, Section 7; Owned Aircraft Indentures, Section
4.02(e)) Such recordation of the Indenture and other documents with respect to
each Aircraft is intended to give the relevant Loan Trustee a first priority
perfected security interest in such Aircraft whenever it is located in the
United States or any of its territories and possessions. The Convention provides
that such security interest will also be recognized, with certain limited
exceptions, in those jurisdictions that have ratified or adhere to the
Convention.
 
     So long as no Lease Event of Default exists, America West has the right to
register the Leased Aircraft subject to any Lease in a country other than the
United States at its own expense in connection with a permitted sublease of such
Aircraft to a permitted foreign air carrier, subject to certain conditions set
forth in the related Participation Agreement. These conditions include a
requirement that the lien of the applicable Indenture continue as a first
priority security interest in the applicable Aircraft. (Leases, Section 7.1.2;
Participation Agreements, Section 7.6.11) The Owned Aircraft Indentures contain
comparable provisions with respect to registration of the Owned Aircraft outside
of the United States in connection with a permitted lease of the Owned Aircraft.
(Owned Aircraft Indentures, Section 4.02(e))
 
     Liens
 
     America West is required to maintain each Aircraft free of any liens, other
than the rights of the relevant Loan Trustee, the holders of the related
Equipment Notes, America West and, with respect to a Leased Aircraft, the Owner
Participant and Owner Trustee arising under the applicable Indenture, the Lease
(in the case of a Leased Aircraft) or the other operative documents related
thereto, and other than certain limited liens permitted under such documents,
including but not limited those listed below; provided that in the case of each
of the liens described below in clauses (1), (2) and (3), such liens and
                                       81
<PAGE>   83
 
proceedings do not involve any material risk of the sale, forfeiture or loss of
such Aircraft or the interest of any Participant therein or impair the lien of
the relevant Indenture. (Leases, Section 6; Owned Aircraft Indentures, Section
4.01)
 
     Additional Permitted Liens
 
     (1) Liens for taxes either not yet due or being contested in good faith by
         appropriate proceedings.
 
     (2) Materialmen's, mechanics' and other similar liens arising in the
         ordinary course of business and securing obligations that either are
         not yet delinquent or are being contested in good faith by appropriate
         proceedings.
 
     (3) Judgment liens so long as such judgment is discharged or vacated within
         60 days or the execution of such judgment is stayed pending appeal and
         discharged, vacated or reversed within 60 days after expiration of such
         stay.
 
     (4) Insurers' salvage rights.
 
     (5) Any other lien as to which America West has provided a bond or other
         security adequate in the reasonable opinion of the related Owner
         Trustee or Loan Trustee, as the case may be.
 
     Replacement of Parts; Alterations
 
     America West is obligated to replace all parts at its expense that may from
time to time be incorporated or installed in or attached to any Aircraft and
that may become lost, damaged beyond repair, worn out, stolen, seized,
confiscated or rendered permanently unfit for use. America West or any permitted
sublessee has the right, at its own expense, to make such alterations,
modifications and additions with respect to each Aircraft as it deems desirable
in the proper conduct of its business and to remove parts which it deems to be
obsolete or no longer suitable or appropriate for use, so long as such
alteration, modification, addition or removal does not materially diminish the
fair market value, utility, or remaining useful life of the related Aircraft,
airframe or engine or invalidate the Aircraft's airworthiness certificate.
(Leases, Section 8.1 and Annex C; Owned Aircraft Indentures, Section 4.04(d))
 
     Insurance
 
     America West is required to maintain, at its expense (or at the expense of
a permitted lessee, in the case of the Owned Aircraft, or a permitted sublessee,
in the case of a Leased Aircraft), all-risk aircraft hull insurance covering
each Aircraft, at all times in an amount not less than the stipulated loss value
of the Aircraft (which exceeds the aggregate outstanding principal amount of the
Equipment Notes related to such Aircraft, together with accrued interest
thereon) or, in the case of any Owned Aircraft, the aggregate outstanding
principal amount of the Equipment Notes relating to such Aircraft together with
six months of interest accrued thereon. However, after giving effect to
self-insurance permitted as described below, the amount payable under such
insurance may be less than such amounts payable with respect to the Equipment
Notes. In the event of a loss involving insurance proceeds in excess of
$5,000,000 per occurrence, if the insurers make payment to other than the
repairer of such loss, such proceeds up to the stipulated loss value of the
relevant Aircraft will be payable to the applicable Loan Trustee, for so long as
the relevant Indenture shall be in effect. In the event of a loss involving
insurance proceeds of up to $5,000,000 such proceeds will be payable directly to
America West so long as an Indenture Event of Default does not exist with
respect to the Owned Aircraft Indentures or (in the case of a Leased Aircraft)
the Owner Trustee has not notified the insurance underwriters that a Lease Event
of Default exists. So long as the loss does not constitute an Event of Loss,
insurance proceeds will be applied to repair or replace the property. (Leases,
Section 11 and Annex D; Owned Aircraft Indentures, Section 4.06)
 
     In addition, America West is obligated to maintain comprehensive airline
liability insurance at its expense (or at the expense of a permitted lessee, in
the case of an Owned Aircraft, or a permitted sublessee, in the case of a Leased
Aircraft), including, without limitation, passenger legal liability, bodily
injury liability, property damage liability and contractual liability (exclusive
of manufacturer's product
 
                                       82
<PAGE>   84
 
liability insurance) insurance with respect to each Aircraft. Insurers of
recognized responsibility must underwrite such liability insurance. The amount
of such liability insurance coverage per occurrence may not be less than the
amount of comprehensive airline liability insurance from time to time applicable
to aircraft owned or leased and operated by America West of the same type and
operating on similar routes as such Aircraft. (Leases, Section 11.1 and Annex D;
Owned Aircraft Indentures, Section 4.06)
 
     America West is also required to maintain war-risk, hijacking or allied
perils insurance if it (or any permitted sublessee or lessee) operates any
Aircraft, airframe or engine in any area of recognized hostilities (unless
governmental indemnity in lieu thereof is obtained) or if America West (or any
permitted sublessee or lessee) maintains such insurance with respect to other
aircraft operated on the same routes on which the Aircraft is operated. (Leases,
Annex D; Owned Aircraft Indentures, Section 4.06)
 
     America West may self-insure under a program applicable to all aircraft in
its fleet, but the amount of such self-insurance in the aggregate may not exceed
50% of the largest replacement value of any single aircraft in America West's
fleet or 1.5% of the average aggregate insurable value (during the preceding
calendar year) of all aircraft on which America West carries insurance,
whichever is less, unless an insurance broker of national standing shall certify
that the standard among all other major U.S. airlines is a higher level of
self-insurance, in which case America West may self-insure the Aircraft to such
higher level. In addition, America West may self-insure to the extent of any
applicable deductible per Aircraft that does not exceed industry standards for
major U.S. airlines. (Leases, Section 11.1 and Annex D; Owned Aircraft
Indentures, Section 4.06(d))
 
     In respect of each Aircraft, America West is required to name as additional
insured parties the relevant Loan Trustee and holders of the Equipment Notes and
(in the case of the Leased Aircraft) the relevant Owner Participant and Owner
Trustee, in its individual capacity and as owner of such Aircraft, and in some
cases certain other parties under all liability, hull and property and war risk,
hijacking and allied perils insurance policies required with respect to such
Aircraft. In addition, the insurance policies maintained under the Leases and
the Owned Aircraft Indenture will be required to provide that, in respect of the
interests of such additional insured persons, the insurance shall not be
invalidated or impaired by any act or omission of America West or any other
person and to insure the respective interests of such additional insured
persons, regardless of any breach or violation of any representation, warranty,
declaration, term or condition contained in such policies by America West, any
permitted sublessee or any other person. (Leases, Annex D; Owned Aircraft
Indentures, Section 4.06)
 
     Lease Termination
 
     Unless a Lease Event of Default shall have occurred and be continuing,
America West may terminate any Lease on any Lease Payment Date occurring after
the fifth anniversary of the date on which such Lease commenced, if it makes a
good faith determination that the Leased Aircraft subject to such Lease is
economically obsolete or surplus to its requirements. America West is required
to give notice of its intention to exercise its right of termination described
in this paragraph at least 90 days prior to the proposed date of termination,
which notice may be withdrawn up to ten Business Days prior to such proposed
date; provided that America West may give only five such termination notices. In
such a situation, unless the Owner Trustee elects to retain title to such
Aircraft, America West is required to use commercially reasonable efforts to
sell such Aircraft as an agent for such Owner Trustee, and Owner Trustee will
sell such Aircraft on the date of termination to the highest cash bidder. If
such sale occurs, the Equipment Notes related thereto are required to be
prepaid. If the net proceeds to be received from such sale are less than the
termination value for such Aircraft (which is set forth in a schedule to each
Lease), America West is required to pay to the applicable Owner Trustee an
amount equal to the excess, if any, of the applicable termination value for such
Aircraft over such net proceeds. Upon payment of termination value for such
Aircraft and an amount equal to the Make-Whole Premium, if any, payable on such
date of payment, together with certain additional amounts, the lien of the
relevant Indenture will be released, the relevant Lease will terminate, and the
obligation of America West thereafter to make scheduled rent payments under such
Lease will cease. (Leases, Section 9; Leased Aircraft Indentures, Sections
2.10(b) and 10.01)
                                       83
<PAGE>   85
 
     The Owner Trustee under any Lease has the option to retain title to the
Leased Aircraft subject thereto if America West has given a notice of
termination under such Lease. In such event, such Owner Trustee will pay to the
applicable Loan Trustee an amount sufficient to prepay the outstanding principal
of and interest on the Equipment Notes issued with respect to such Aircraft (but
America West will be obligated to pay the Make-Whole Premium in respect
thereof), in which case the lien of the relevant Indenture will be released, the
relevant Lease will terminate and the obligation of America West thereafter to
make scheduled rent payments under such Lease will cease. (Leases, Section 9;
Leased Aircraft Indentures, Sections 2.10(b) and 10.01)
 
     Events of Loss
 
     If an Event of Loss occurs with respect to the airframe or the airframe and
engines of an Aircraft, America West must elect within 45 days after such
occurrence either to make payment with respect to such Event of Loss or to
replace such airframe and any such engines. Not later than the first Business
Day following the earliest of the 120th day following the date of occurrence of
such Event of Loss and the fourth Business Day following the receipt of the
insurance proceeds in respect of such Event of Loss, America West must take
either of the steps noted below:
 
        Alternative Steps Required Upon an Event of Loss
 
        (1) Pay to the applicable Owner Trustee (in the case of a Leased
            Aircraft) or to the Owned Aircraft Trustee (in the case of the Owned
            Aircraft) the stipulated loss value of such Aircraft (in the case of
            a Leased Aircraft) or the outstanding principal amount of the
            Equipment Notes (in the case of an Owned Aircraft), together with
            certain additional amounts, but, in any case, without any Make-Whole
            Premium.
 
        (2) Unless any Lease Event of Default or failure to pay basic rent under
            the relevant Lease (in the case of a Leased Aircraft), an Indenture
            Event of Default or failure to pay principal or interest under the
            Owned Aircraft Indenture (in the case of the Owned Aircraft) or
            certain bankruptcy defaults shall have occurred and be continuing,
            substitute an airframe (or airframe and one or more engines, as the
            case may be) for the airframe, or airframe and engine(s), that
            suffered such Event of Loss. (Leases, Sections 10.1.1, 10.1.2 and
            10.1.3; Leased Aircraft Indentures, Section 2.10(a); Owned Aircraft
            Indentures, Sections 2.10 and 4.05(a))
 
     If America West elects to replace an airframe (or airframe and one or more
engines, as the case may be) that suffered such Event of Loss, it shall, in the
case of a Leased Aircraft, convey to the related Owner Trustee title to an
airframe (or airframe and one or more engines, as the case may be), and such
replacement airframe or airframe and engines must be the same model as the
airframe or airframe and engines to be replaced or an improved model, with a
value, utility and remaining useful life (without regard to hours or cycles
remaining until the next regular maintenance check) at least equal to the
airframe or airframe and engines to be replaced, assuming that such airframe and
such engines had been maintained in accordance with the related Lease. America
West is also required to provide to the relevant Loan Trustee and (in the case
of a Leased Aircraft) the relevant Owner Trustee and Owner Participant
reasonably acceptable opinions of counsel to the effect, among other things,
that certain specified documents have been duly filed under the Transportation
Code (or other relevant jurisdiction of registration) and such Owner Trustee and
Leased Aircraft Trustee (as assignee of lessor's rights and interests under the
Lease), in the case of a Leased Aircraft, or the Owned Aircraft Trustee, in the
case of an Owned Aircraft, will be entitled to receive the benefits of Section
1110 of the U.S. Bankruptcy Code with respect to any such replacement airframe
(unless, as a result of a change in law or court interpretation, such benefits
are not then available). (Leases, Sections 10.1.3 and 10.3; Owned Aircraft
Indentures, Section 4.05(c))
 
     If America West elects not to replace such airframe, or airframe and
engine(s), then upon payment of the outstanding principal amount of the
Equipment Notes issued with respect to such Aircraft (in the case of an Owned
Aircraft) or the stipulated loss value for such Aircraft (in the case of a
Leased
                                       84
<PAGE>   86
 
Aircraft), together with all additional amounts then due and unpaid with respect
to such Aircraft, which must be at least sufficient to pay in full as of the
date of payment thereof the aggregate unpaid principal amount under such
Equipment Notes together with accrued but unpaid interest thereon and all other
amounts due and owing in respect of such Equipment Notes, the lien of the
Indenture and (in the case of a Leased Aircraft) the Lease relating to such
Aircraft shall terminate with respect to such Aircraft, the obligation of
America West thereafter to make the scheduled rent payments (in the case of a
Leased Aircraft) or interest and principal payments (in the case of an Owned
Aircraft) with respect thereto shall cease. Additionally, in the case of a
Leased Aircraft the related Owner Trustee shall transfer all of its right, title
and interest in and to the related Aircraft to America West (or, if directed by
America West, the Aircraft insurers). The stipulated loss value and/or other
payments made under the Leases or the Owned Aircraft Indentures, as the case may
be, by America West shall be deposited with the applicable Loan Trustee. Amounts
in excess of the amounts due and owing under the Equipment Notes issued with
respect to such Aircraft will be distributed by such Loan Trustee to the
applicable Owner Trustee or to America West, as the case may be. (Leases,
Section 10.1.2; Leased Aircraft Indentures, Sections 3.02 and 10.01; Owned
Aircraft Indentures, Sections 2.10 and 4.05(a)(ii))
 
     If an Event of Loss occurs with respect to engines alone, America West will
be required to replace such engines within 60 days after the occurrence of such
Event of Loss with another engine, free and clear of all liens (other than
certain permitted liens). Such replacement engine shall be the same make and
model as the engines to be replaced, or an improved model, suitable for
installation and use on the Airframe, and having a value, utility and remaining
useful life (without regard to hours or cycles remaining until overhaul) at
least equal to the engines to be replaced, assuming that such engines had been
maintained in accordance with the relevant Lease or the Owned Aircraft
Indentures, as the case may be, immediately prior to the occurrence of the Event
of Loss. (Leases, Section 10.2; Owned Aircraft Indentures, Section 4.05(a)(i))
America West may, whether or not an Event of Loss shall have occurred with
respect to any engines, replace such engines with a replacement engine
satisfying the same conditions for a replacement engine following an Event of
Loss. (Leases, Section 10.2.3; Owned Aircraft Indentures, Section 4.04(e))
 
     An "Event of Loss" with respect to an Aircraft, airframe or any engines
means any of the events noted below:
 
       Events of Loss With Respect to an Aircraft, Airframe or any Engine
 
        (1) The destruction of such property, damage to such property beyond
            economic repair or rendition of such property permanently unfit for
            normal use.
 
        (2) The actual or constructive total loss of such property or any damage
            to such property or requisition of title or use of such property
            which results in an insurance settlement with respect to such
            property on the basis of a total loss or a constructive or
            compromised total loss.
 
        (3) Any theft, hijacking or disappearance of such property for a period
            of 180 days or more or, if earlier, the first to occur of the last
            day of the term of the related Lease (if such property is subject to
            a Lease) or the date on which America West has confirmed in writing
            that it cannot recover such property.
 
        (4) Any seizure, condemnation, confiscation, taking or requisition of
            title to such property by any non-U.S. governmental entity or
            purported non-U.S. governmental entity (other than the country of
            registration of the relevant Aircraft) for a period exceeding 180
            days (exceeding 90 days in the case of a requisition of title) or,
            if earlier, at the end of the term of such Lease (in the case of a
            Leased Aircraft).
 
        (5) In the case of any Leased Aircraft, any seizure, condemnation,
            confiscation, taking or requisition of use of such property by any
            U.S. government entity that continues until the 30th day after the
            last day of the term of the relevant Lease (unless the Owner Trustee
            shall have elected not to treat such event as an Event of Loss).
                                       85
<PAGE>   87
 
        (6) As a result of any law, rule, regulation, order or other action by
            the FAA or any governmental entity, the use of such property in the
            normal course of America West's business of passenger air
            transportation is prohibited for 180 days, unless America West,
            prior to the expiration of such 180 day period, shall have
            undertaken and shall be diligently carrying forward steps which are
            necessary or desirable to permit the normal use of such property by
            America West, but in any event if such use shall have been
            prohibited for a period of two consecutive years; provided that no
            Event of Loss shall be deemed to have occurred if such prohibition
            has been applicable to America West's entire U.S. registered fleet
            of similar property and America West, prior to the expiration of
            such two-year period, shall have conformed at least one unit of such
            property in its fleet to the requirements of any such law, rule,
            regulation, order or other action and commenced regular commercial
            use of the same and shall be diligently carrying forward, in a
            manner which does not discriminate against applicable property in so
            conforming such property, steps which are necessary or desirable to
            permit the normal use of such property by America West, but in any
            event if such use shall have been prohibited for a period of three
            years or, in the case of the Leased Aircraft, such use shall be
            prohibited at the expiration of the term of the relevant Lease.
            (Leases, Annex A; Owned Aircraft Indentures, Annex A)
 
     Renewal and Purchase Options
 
     With respect to any Leased Aircraft, America West will have the option to
purchase such Aircraft and terminate the related Lease prior to the end of the
term of such Lease either on the Lease Payment Date, if any, agreed to by the
Owner Participant for such Aircraft in connection with such purchase option or
under certain circumstances, on any Lease Payment Date, if America West would be
required to make certain indemnity payments with respect to such Aircraft in
excess of a certain designated amount, which indemnity payments could be avoided
through a purchase by America West of such Aircraft (each an "Early Purchase
Option"). In connection with the exercise of any Early Purchase Option, America
West is required with respect to the Equipment Notes relating to the Aircraft
being purchased either (x) to pay to the related Owner Trustee funds at least
sufficient to pay any principal of and interest and Make-Whole Premium, if any,
on such Equipment Notes or (y) to assume on a full recourse basis the
obligations of the related Owner Trustee under such Equipment Notes, the related
Indenture and the related Participation Agreement. (Leases, Section 17.3; Leased
Aircraft Indentures, Sections 2.10 and 2.15)
 
     If America West elects to purchase and pay the amount described in clause
(x) above, then upon payment to the related Owner Trustee of the full purchase
price for such Aircraft determined in accordance with such Lease and all other
amounts owing to the parties to the related Participation Agreement, such Owner
Trustee will transfer all of its right, title and interest in and to such
Aircraft to America West and the related Lease and the Lien of the related
Indenture will terminate. If America West elects to purchase the Aircraft and
assume the obligations of such Owner Trustee described in clause (y) above, then
the related operative agreements will be amended to provide for the assumption
of such obligations on a full recourse basis by America West, maintaining for
the benefit of the holders of such Equipment Notes the security interest in such
Aircraft created by the related Indenture. In the event of such an assumption,
America West will either furnish an opinion to the relevant Leased Aircraft
Trustee that such assumption does not result in a taxable gain or loss for the
Certificateholder for U.S. federal tax purposes or an indemnity for the benefit
of the Certificateholders in form and substance reasonably satisfactory to the
relevant Leased Aircraft Trustee. See "Certain U.S. Federal Income Tax
Consequences -- Taxation of Certificateholders Generally." (Leases, Section
17.3; Leased Aircraft Indentures, Sections 2.10 and 2.15)
 
     At the end of the term of each Lease after final maturity of the related
Equipment Notes and subject to certain conditions, America West will have
certain options to renew such Lease for additional limited periods. In addition,
America West may have the right at the end of the term of each Lease to purchase
the Aircraft subject thereto for an amount to be calculated in accordance with
the terms of such Lease. (Leases, Section 17)
 
                                       86
<PAGE>   88
 
     Events of Default under the Leases
 
     Lease Events of Default under each Lease include, among other things, the
items listed below:
 
        Lease Events of Default
 
        (1) Failure by America West to make any payment of basic rent,
            stipulated loss value or termination value under such Lease within
            ten Business Days after the same shall have become due, or failure
            by America West to pay any other amount due under such Lease or
            under any other related operative document within 30 days from and
            after the date of any written demand therefor from the Owner
            Trustee.
 
        (2) Failure by America West to make any excluded payment (as defined in
            the Leases) within 30 days after written notice that such failure
            constitutes a Lease Event of Default is given by the relevant Owner
            Participant to America West and the relevant Loan Trustee.
 
        (3) Failure by America West to carry and maintain insurance on and in
            respect of the Aircraft, airframe and engines, in accordance with
            the provisions of such Lease.
 
        (4) Failure by America West to perform or observe any other covenant or
            agreement to be performed or observed by it under such Lease or the
            related Participation Agreement or any other related operative
            document (other than the related tax indemnity agreement between
            America West and the Owner Participant), and such failure shall
            continue unremedied for a period of 30 days after written notice of
            such failure by the applicable Owner Trustee or Loan Trustee unless
            such failure is capable of being corrected and America West shall be
            diligently proceeding to correct such failure, in which case there
            shall be no Lease Event of Default unless and until such failure
            shall continue unremedied for a period of 180 days after receipt of
            such notice.
 
        (5) Any representation or warranty made by America West in such Lease or
            the related Participation Agreement or in any other related
            operative document (other than in the related tax indemnity
            agreement between America West and the Owner Participant) shall
            prove to have been untrue or inaccurate in any material respect at
            the time made, such representation or warranty is material at the
            time in question and the same shall remain uncured (to the extent of
            the adverse impact thereof) for more than 30 days after the date of
            written notice thereof to America West.
 
        (6) The occurrence of certain voluntary events of bankruptcy,
            reorganization or insolvency of America West or the occurrence of
            involuntary events of bankruptcy, reorganization or insolvency which
            shall continue undismissed, unvacated or unstayed for a period of 90
            days. (Leases, Section 14)
 
     Indenture Events of Default under the Owned Aircraft Indenture are
discussed above under "-- Indenture Defaults, Notice and Waiver".
 
     Remedies Exercisable upon Events of Default under the Lease
 
     If a Lease Event of Default has occurred and is continuing, the applicable
Owner Trustee may (or, so long as the Indenture shall be in effect, the
applicable Loan Trustee may, subject to the terms of the Indenture) exercise one
or more of the remedies provided in such Lease with respect to the related
Aircraft. These remedies include the right to repossess and use or operate such
Aircraft, to rescind or terminate such Lease, to sell or re-lease such Aircraft
free and clear of America West's rights, except as set forth in the Lease, and
retain the proceeds, and to require America West to pay, as liquidated
 
                                       87
<PAGE>   89
 
damages, any due and unpaid basic rent plus an amount, at such Owner Trustee's
(or, subject to the terms of the relevant Leased Aircraft Indenture, the Leased
Aircraft Trustee's) option, set forth below:
 
        Alternative Amount of Payment Amount upon a Lease Event of Default
 
        (1) The excess of the present value of all unpaid rent during the
            remainder of the term of such Lease over the present value of the
            fair market rental value of such Aircraft for the remainder of the
            term of such Lease; or
 
        (2) The excess of the stipulated loss value of such Aircraft over the
            fair market sales value of such Aircraft or, if such Aircraft has
            been sold, the net sales proceeds from the sale of such Aircraft.
            (Leases, Section 15; Leased Aircraft Indentures, Section 4.04)
 
     Remedies under the Owned Aircraft Indentures are discussed above under
"-- Remedies".
 
     Transfer of Owner Participant Interests
 
     Subject to certain restrictions, each Owner Participant may transfer all or
any part of its interest in the related Leased Aircraft. (Participation
Agreements, Section 10.1.1)
 
                  CERTAIN U.S. FEDERAL INCOME TAX CONSEQUENCES
 
EXCHANGE OF OLD CERTIFICATES FOR NEW CERTIFICATES
 
     The following summary describes all principal U.S. federal income tax
consequences to Certificateholders of the exchange of Old Certificates for New
Certificates. This summary is addressed to the beneficial owners of Certificates
that are citizens or residents of the United States, corporations, partnerships
or other entities created or organized in or under the laws of the United States
or any state therein, or estates the income of which is subject to U.S. federal
income taxation regardless of its source, trusts the income of which is subject
to U.S. federal income taxation regardless of its source or trusts if a court in
the United States is able to exercise primary supervision over the
administration of the trust and one or more U.S. fiduciaries have authority to
control substantial decisions of the trust, that will hold the Certificates as
capital assets.
 
     The exchange of Old Certificates for New Certificates (the "Exchange")
pursuant to the Exchange Offer will not be a taxable event for U.S. federal
income tax purposes. The receipt of Certificates in the Exchange will be treated
as a continuation of the original investment in the Certificates. As a result, a
holder of an Old Certificate whose Old Certificate is accepted in an Exchange
Offer will not recognize gain or loss on the Exchange. A tendering holder's tax
basis in the New Certificates will be the same as such holder's tax basis in its
Old Certificates. A tendering holder's holding period for the New Certificates
received pursuant to the Exchange Offer will include its holding period for the
Old Certificates surrendered therefor.
 
     THE FOREGOING SUMMARY OF U.S. FEDERAL INCOME TAX CONSEQUENCES IS FOR
GENERAL INFORMATION ONLY AND IS NOT TAX ADVICE. ACCORDINGLY, ALL HOLDERS OF OLD
CERTIFICATES ARE ADVISED TO CONSULT THEIR OWN TAX ADVISORS REGARDING THE U.S.
FEDERAL, STATE AND LOCAL TAX CONSEQUENCES OF THE EXCHANGE OF OLD CERTIFICATES
FOR NEW CERTIFICATES AND OF THE OWNERSHIP AND DISPOSITION OF NEW CERTIFICATES
RECEIVED IN THE EXCHANGE OFFER IN LIGHT OF THEIR OWN PARTICULAR CIRCUMSTANCES.
 
                              ERISA CONSIDERATIONS
 
     In general, employee benefit plans subject to Title I of the Employee
Retirement Income Security Act of 1974, as amended ("ERISA") or Section 4975 of
the Internal Revenue Code of 1986, as amended (the "Code") or entities which may
be deemed to hold the assets of any such plan (each, an "ERISA Plan") will be
eligible to purchase the Certificates, subject to certain conditions and the
circumstances applicable to such ERISA Plans.
 
                                       88
<PAGE>   90
 
     A fiduciary of an employee benefit plan subject to ERISA should consider
fiduciary standards under ERISA in the context of the particular circumstances
of such plan before authorizing an investment in the Certificates. Such
fiduciaries should determine whether the investment satisfies ERISA's
diversification and prudence requirements and whether the investment is in
accordance with the documents and instruments governing the plan. In addition,
ERISA and the Code prohibit a wide range of transactions ("Prohibited
Transactions") involving an ERISA Plan and persons who have certain specified
relationships to the ERISA Plan ("parties in interest", within the meaning of
ERISA and "disqualified persons", within the meaning of the Code). Such
transactions may require "correction" and may cause an ERISA Plan fiduciary to
incur certain liabilities and the parties in interest or disqualified persons to
be subject to excise taxes.
 
     Each of the Owner Participants, the manufacturers of the Aircraft, the
holders of the Equipment Notes, the Initial Purchasers, the Company, the Escrow
Agent, the Depositary and the Liquidity Provider may be a party in interest or a
disqualified person with respect to an ERISA Plan purchasing the Certificates;
therefore, the purchase by an ERISA Plan of the Certificates may give rise to a
direct or indirect Prohibited Transaction. Any person who is, or who in
acquiring the Certificates is or may be using the assets of, an ERISA Plan may
purchase the Certificates, if such person determines that a statutory or an
administrative exemption from the Prohibited Transaction rules discussed below
or otherwise available is applicable to such person's purchase and holding of
the Certificates (or a participation interest therein).
 
     Certain statutory or administrative exemptions from the Prohibited
Transaction rules under ERISA and the Code may be available to an ERISA Plan
which is purchasing the Certificates. Included among these exemptions are: PTCE
90-1, regarding investments by insurance company pooled separate accounts; PTCE
91-38, regarding investments by bank collective investment funds; PTCE 84-14,
regarding transactions effected by a qualified professional asset manager; PTCE
95-60, regarding investments by insurance company general accounts or PTCE
96-23, regarding investments by an in-house professional asset manager. Certain
of the exemptions, however, do not afford relief from the Prohibited Transaction
rules under Section 406(b) of ERISA and Section 4975(c)(1)(E)-(F) of the Code.
In addition, there can be no assurance that any of these administrative
exemptions will be available with respect to any particular transactions
involving the Certificates.
 
     The U.S. Department of Labor ("DOL") has issued individual administrative
exemptions to certain of the underwriters which are substantially the same as
the administrative exemption issued to Morgan Stanley & Co. Incorporated
(Prohibited Transaction Exemption 90-24 et al., Exemption Application NO. D-8019
et al, 55 Fed. Reg. 20,548 (1990) (the "Underwriter Exemption")) which generally
exempts from certain of the Prohibited Transaction rules the initial purchase,
the holding and the subsequent resale by an ERISA Plan of certificates in
certain pass through trusts, the assets of which pass through trust consist of
secured credit instruments that bear interest or are purchased at a discount in
transaction by or between business entities (including qualified equipment
trusts certificates secured by leases). The limited relief provided by the DOL
in the Underwriter Exemption is subject to several other conditions, including a
requirement that certificates acquired by an ERISA Plan under the Underwriter
Exemption have received a rating at the time of acquisition by the ERISA Plan
that is in one of the three highest categories from either Standard & Poor's or
Moody's. Under the Underwriting Exemption, an equipment trust certificate
secured by a lease will be considered qualified only under certain
circumstances. The Underwriter Exemption also requires that the acquisition of
certificates by an ERISA Plan be on terms (including the price for the
certificate) that are at least as favorable to an ERISA Plan as they would be in
an arm's-length transaction with an unrelated party, and that the rights and
interests evidenced by the certificates must not be subordinated to the rights
and interests evidenced by other certificates of the same trust estate.
 
     With respect to the investment restrictions set forth in the Underwriter
Exemption, an investment in a Certificate will evidence both an interest in the
respective Original Trust as well as an interest in the Deposits held in escrow
by an Escrow Agent for the benefit of the Certificateholder. Under the terms of
the Escrow Agreement, the proceeds from the Offering of the Certificates of each
Class will be paid over by the Initial Purchasers to the Depositary on behalf of
the Escrow Agreement (for the benefit of such
                                       89
<PAGE>   91
 
Certificateholders as the holders of the Escrow Receipts) and will not
constitute property of the Original Trusts. Under the terms of each Escrow
Agreement, the Escrow Agent will be irrevocably instructed to enter into the
Deposit Agreement with the Depositary and to effect withdrawals upon the receipt
of appropriate notice from the relevant Trustee so as to enable such Trustee to
purchase the identified Equipment Notes on the terms and conditions set forth in
the Note Purchase Agreement. Interests on the Deposits relating to each Trust
will be paid to the Certificateholders of such Trust as Receiptholders through a
Paying Agent appointed by the Escrow Agent. Pending satisfaction of such
conditions and withdrawal of such Deposits, the Escrow Agent's rights with
respect to the Deposits will remain plan assets subject to the fiduciary
responsibility provisions of ERISA and the Prohibited Transaction rules.
 
     The DOL has issued an amendment to the Underwriter Exemption, 62 FR 39,021
(July 21, 1997), which allows the assets of a pass through trust to include a
prefunding account under certain circumstances. The relief provided by this
amendment is subject to several conditions, including a requirement that the
prefunding period end no later than the earliest to occur of the date the amount
on deposit in the prefunding account is less than the minimum dollar amount
specified in the pooling and servicing agreement, the date on which an event of
default occurs under the pooling and servicing agreement, or the date which is
the later of three months or 90 days after the closing date. However, there can
be no assurance that the DOL would agree that the prefunding restrictions would
not apply in these circumstances. Moreover, even if such restrictions would not
apply, no monitoring or other measures will be taken to ensure that all of the
conditions of the Underwriter Exemption, as amended, will be satisfied.
 
     If an ERISA Plan acquires a Certificate, the ERISA Plan's assets may
include both the Certificate acquired and an undivided interest in the
underlying assets of the Trust, unless the actual investment by "benefit plan
investors" in the Certificates is not "significant" within the meaning of the
DOL plan assets regulations. Consequently, the Trust assets could be deemed to
be "plan assets" of such ERISA Plan for purposes of the fiduciary responsibility
provisions of ERISA and the Prohibited Transaction rules. Any person who
exercises any authority or control with respect to the management or disposition
of the assets of an ERISA Plan is considered to be a fiduciary of such ERISA
Plan. The Trustee could, therefore, become a fiduciary of ERISA Plans that have
invested in the Certificates and be subject to general fiduciary requirements of
ERISA in exercising its authority with respect to the management of the assets
of the Trust. If the Trustee becomes a fiduciary with respect to the ERISA Plans
purchasing the Certificates, there may be an improper delegation by such ERISA
Plans of the responsibility to manage plan assets. In order to avoid such
prohibited transactions, each investing ERISA Plan, by purchasing the
Certificates, will be deemed to have directed the Trust to invest in the assets
held in such trust. Any ERISA Plan purchasing the Certificates must ensure that
any statutory or administrative exemption from the Prohibited Transaction rules
on which such ERISA Plan relies with respect to its purchase or holding of the
Pass Through Certificates also applies to such ERISA Plan's indirect holding of
the assets of the Trust.
 
     Governmental plans and certain church plans (each as defined under ERISA)
are not subject to the Prohibited Transaction rules. Such plans may, however, be
subject to federal, state or local laws or regulations which may affect their
investment in the Certificates. Any fiduciary of such a governmental or church
plan considering a purchase of the Certificates must determine the need for, and
the availability, if necessary, of any exemptive relief under any such laws or
regulations.
 
     The foregoing discussion is general in nature and is not intended to be all
inclusive. Any fiduciary of an ERISA Plan, governmental plan or church plan
considering the purchase and holding of the Certificates should consult with its
legal advisors regarding the consequences of such purchase and holding. By its
purchase and acceptance of a Certificate, each Certificateholder will be deemed
to have represented and warranted either no ERISA plan assets have been used to
purchase such Certificate or one or more prohibited transaction statutory or
administrative exemptions applies such that the use of such ERISA Plan assets to
purchase and hold such Certificate will not constitute a non-exempt Prohibited
Transaction.
 
                                       90
<PAGE>   92
 
     EACH ERISA PLAN FIDUCIARY (AND EACH FIDUCIARY FOR A GOVERNMENTAL OR CHURCH
PLAN SUBJECT TO RULES SIMILAR TO THOSE IMPOSED ON ERISA PLANS UNDER ERISA)
SHOULD CONSULT WITH ITS LEGAL ADVISOR CONCERNING AN INVESTMENT IN ANY OF THE
CERTIFICATES.
 
                              PLAN OF DISTRIBUTION
 
     Each broker-dealer that receives New Certificates for its own account
pursuant to the Exchange Offer must acknowledge that it will deliver a
prospectus in connection with any resale of such New Certificates. This
Prospectus, as it may be amended or supplemented from time to time, may be used
by a broker-dealer in connection with resales of New Certificates received in
exchange for Old Certificates where such Old Certificates were acquired as a
result of market-making activities or other trading activities. The Company has
agreed that, starting on the Expiration Date and ending on the close of business
180 days after the Expiration Date, it will make this Prospectus, as amended or
supplemented, available to any broker-dealer for use in connection with any such
resale. In addition, until such date all broker-dealers effecting transactions
in the New Certificates may be required to deliver a prospectus.
 
     The Company will not receive any proceeds from any sale of New Certificates
by broker-dealers. New Certificates received by broker-dealers for their own
account pursuant to the Exchange Offer may be sold from time to time in one or
more transactions in the over-the-counter market, in negotiated transactions,
through the writing of options on the New Certificates or a combination of such
methods of resale, at market prices prevailing at the time of resale, at prices
related to such prevailing market prices or negotiated prices. Any such resale
may be made directly to purchasers or to or through brokers or dealers who may
receive compensation in the form of commissions or concessions from any such
broker-dealer and/or the purchasers of any such New Certificates. Any
broker-dealer that resells New Certificates that were received by it for its own
account pursuant to the Exchange Offer and any broker or dealer that
participates in a distribution of such New Certificates may be deemed to be an
"underwriter" within the meaning of the Securities Act and any profit of any
such resale of New Certificates and any commissions or concessions received by
any such persons may be deemed to be underwriting compensation under the
Securities Act. The Letter of Transmittal states that by acknowledging that it
will deliver and by delivering a prospectus, a broker-dealer will not be deemed
to admit that it is an "underwriter" within the meaning of the Securities Act.
 
     Starting on the Expiration Date, the Company will promptly send additional
copies of this Prospectus and any amendment or supplement to this Prospectus to
any broker-dealer that requests such documents in the Letter of Transmittal. The
Company has agreed to pay all expenses incident to the Exchange Offer other than
commissions or concessions of any brokers or dealers, fees of counsel to the
Holders and certain transfer taxes, and will indemnify the Holders of the New
Certificates (including any broker-dealers) against certain liabilities,
including liabilities under the Securities Act.
 
                                 LEGAL MATTERS
 
     The validity of the New Certificates is being passed upon for America West
by Morris, James, Hitchens & Williams, Wilmington, Delaware, counsel for
Wilmington Trust Company.
 
                                    EXPERTS
 
     The financial statements and financial statement schedule of America West
Airlines, Inc. as of December 31, 1997 and 1996, and for each of the years in
the three-year period ended December 31, 1997, have been incorporated by
reference herein and in the registration statement in reliance upon the report
of KPMG LLP, independent certified public accountants, incorporated by reference
herein, and upon the authority of said firm as experts in accounting and
auditing.
 
     The references to AvSolutions, AVITAS and BK, and to their respective
appraisal reports, dated as of September 24, 1998, are included herein in
reliance upon the authority of each such firm as an expert with respect to the
matters contained in its appraisal report.
 
                                       91
<PAGE>   93
 
                          APPENDIX I -- INDEX OF TERMS
 
<TABLE>
<CAPTION>
             DEFINITION                PAGE
<S>                                   <C>
Adjusted Expected Distributions.....  62, 63
Administration Expenses.............      62
affiliate...........................       6
Aggregate LTV Collateral Amount.....      64
Aircraft............................       7
Aircraft Operative Agreements.......      47
America West........................       5
Appraised Current Market Value......      64
Appraisers..........................      18
Assumed Aircraft Value..............      74
Assumed Amortization Schedule.......      37
Average Life Date...................      71
AVITAS..............................      18
AVSA................................      17
AvSolutions.........................      18
Base Rate...........................      58
BK..................................      18
Business Day........................      36
Cash Collateral Account.............      56
Cede................................       6
Certificate Account.................      36
Certificate Owners..................      39
Certificateholders..................       5
Certificates........................       5
Class A Certificates................       7
Class A Trust.......................       5
Class B Certificates................       7
Class B Trust.......................       5
Class C Certificates................       7
Class C Trust.......................       5
Class D Certificates................      11
Class D Trust.......................      11
Code................................      88
Company.............................       5
Controlling Party...................      59
Convention..........................      81
Delivery Period.....................       9
Deposit Agreements..................       9
Deposit Make-Whole Premium..........      52
Depositary..........................       9
Deposits............................       9
Depreciation Assumption.............      74
Distribution Dates..................      34
DOL.................................      89
Downgrade Drawing...................      55
DTC.................................   6, 50
</TABLE>
 
<TABLE>
<CAPTION>
             DEFINITION                PAGE
<S>                                   <C>
DTC Participants....................       9
Early Purchase Option...............      86
Eligible Institution................      29
Equipment...........................      77
Equipment Notes.....................       7
ERISA...............................      88
ERISA Plan..........................      88
Escrow Agent........................       7
Escrow Agreement....................       7
Escrow Receipts.....................      53
Event of Loss.......................      85
Exchange............................      88
Exchange Act........................       2
Exchange Agent......................       5
Exchange Offer......................      26
Expected Distributions..............      61
Expiration Date.....................       5
Final Distributions.................      60
Final Drawing.......................      57
Final Legal Distribution Date.......   8, 35
Global Certificates.................   6, 50
H.15(519)...........................      71
Holdings............................      15
Indentures..........................      10
Indirect Participants...............      50
Initial Purchasers..................       5
Intercreditor Agreement.............       7
Interest Drawings...................  11, 54
Issuance Date.......................      26
Lease...............................      10
Lease Event of Default..............      40
Lease Payment Date..................      80
Leased Aircraft.....................      10
Leased Aircraft Indenture...........      10
Leased Aircraft Trustee.............      10
LeisureCo. .........................      15
Letter of Transmittal...............       5
LIBOR...............................      57
Liquidity Event of Default..........      58
Liquidity Expenses..................      61
Liquidity Facility..................  11, 54
Liquidity Obligations...............      11
Liquidity Provider..................       8
Loan Trustees.......................      10
LTV Appraisal.......................      64
LTV Collateral Amount...............      64
</TABLE>
 
                                      A-I-1
<PAGE>   94
 
<TABLE>
<CAPTION>
             DEFINITION                PAGE
<S>                                   <C>
LTV Ratio...........................      64
LTVs................................      38
Make-Whole Premium..................      71
Mandatory Document Terms............      47
Mandatory Economic Terms............      46
Maximum Amount......................      52
Maximum Available Commitment........      54
Minimum Sale Price..................      61
Moody's.............................      20
New Certificates....................       1
Non-Extension Drawing...............      56
Non-Performing Equipment Note.......      55
Non-Premium Amount..................      52
Note Purchase Agreement.............       7
Original Trustee....................       7
Original Trusts.....................       7
Owned Aircraft......................      10
Owned Aircraft Indenture............      10
Owned Aircraft Trustee..............      10
Owner Participant...................      10
Owner Trustee.......................      10
Par Redemption Amount...............      52
Participation Agreement.............      46
Pass Through Trust Agreements.......       7
Paying Agent........................       7
Paying Agent Account................      36
Performance Equipment Note..........      55
Pool Balance........................      37
Pool Factor.........................      37
Prohibited Transactions.............      88
PTC Event of Default................      42
Rating Agencies.....................      20
Receiptholder.......................      53
Registration Event..................      26
</TABLE>
 
<TABLE>
<CAPTION>
             DEFINITION                PAGE
<S>                                   <C>
Registration Rights Agreement.......      26
Regular Distribution Dates..........      34
Remaining Weighted Average Life.....      71
Replacement Facility................      56
Required Amount.....................      54
Scheduled Payments..................   8, 34
SEC.................................       1
Section 1110 Period.................      55
Securities Act......................      26
Series A Equipment Notes............       9
Series B Equipment Notes............       9
Series C Equipment Notes............      10
Series D Equipment Notes............      11
Shelf Registration Statement........      26
Special Distribution Date...........      36
Special Payment.....................      36
Special Payments....................       9
Special Payments Account............      36
Standard & Poor's...................      20
Stated Interest Rates...............      54
Subordination Agent.................       7
Successor Trustee...................       7
Successor Trusts....................       7
Termination Notice..................      58
Threshold Rating....................      56
Transfer Date.......................       7
Transportation Code.................      43
Treasury Yield......................      71
Triggering Event....................       9
Trust Property......................       7
Trustee.............................       7
Trusts..............................       5
Underwriter Exemption...............      89
</TABLE>
 
                                      A-I-2
<PAGE>   95
 
                        APPENDIX II -- APPRAISAL LETTERS
 
                                     A-II-1
<PAGE>   96
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
INTRODUCTION
 
     AVITAS, Inc. has been retained by America West Airlines (the "Client") to
provide its opinion as to the Base Value at date of delivery for six Airbus
A319-100 aircraft and two A320-200 aircraft. The subject aircraft are identified
and their values are set forth in Figure 1 on page 2.
 
     The values presented in this report assume that the aircraft will be in
new, "flyaway" condition and fully certificated for commercial operations. We
have further assumed that the subject aircraft will be operated under the air
transport regulations of a major nation.
 
DEFINITIONS
 
     AVITAS's value definitions, set forth in full in the appendix at the end of
this report, conform to those of the International Society of Transport Aircraft
Trading ("ISTAT") adopted in January 1994, and are summarized as follows:
 
     - BASE VALUE is the appraiser's opinion of the underlying economic value of
       an aircraft in an open, unrestricted, stable market environment with a
       reasonable balance of supply and demand, and assumes full consideration
       of its "highest and best use." An aircraft's Base Value is founded in the
       historical trend of values and in the projection of value trends and
       presumes an arm's-length, cash transaction between willing and
       knowledgeable parties, acting prudently, with an absence of duress and
       with a reasonable period of time for marketing. Base Value typically
       assumes that an aircraft's physical condition is average for an aircraft
       of its type and age, and its maintenance time status is at mid-life,
       mid-time (or benefiting from an above-average maintenance status if it is
       new or nearly new).
 
 WORLD HEADQUARTERS: 1835 Alexander Bell Drive,
 Reston, VA 22091 USA - Telephone 703/476-2300
 FAX: 703/860-5855
 
 AVITAS EUROPE: Palace House, 3 Cathedral St.
 London SE1 9DE - Telephone 0171/716-6621
 FAX: 0171/357-6873
 
 AVITAS ENGINEERING: 815 N.W. 57th Avenue, Suite 203
 Miami, FL 33126 - Telephone 305/267-7332
 FAX: 305/267-7365
 
                          A DET NORSKE VERITAS COMPANY
AIRCRAFT VALUE
 
     AVITAS's opinion as to the value of the subject aircraft is presented below
in millions of U.S. dollars. Base Values are in then-current dollars using a
3.0% inflation rate compounded annually.
 
     The Base Value of a new aircraft is the modal price paid by an average
operator in a single unit or small lot sale. Actual transaction prices may be
either above or below that level due to a number of factors. For example, a
launch order or a large fleet order may result in discounts, whereas a single
unit sale to a small operator who needs a substantial amount of support may be
at or above the list price.
 
                                     A-II-2
 
[AVITAS GLOBE GRAPHIC]
<PAGE>   97
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
     Furthermore, implicit in these values is AVITAS's assumption that the new
aircraft will remain with the original operator for at least two years. If a
newly delivered aircraft comes onto the market, the seller is at an immediate
disadvantage as he is likely to be in competition with the manufacturer who can
offer training and support.
 
                           FIGURE 1
 
<TABLE>
<CAPTION>
  ---------------------------------------------------
                 AMERICA WEST AIRLINES
      SUMMARY OF AIRCRAFT AND SPARE ENGINE VALUES
                    (US$ MILLIONS)
  ---------------------------------------------------
      NO.     TYPE     ENGINES    DELIV. DATE    BV
  ---------------------------------------------------
  <S> <C>   <C>        <C>        <C>           <C>
       1    A319-100   V2524-A5   Oct-98        38.0
  ---------------------------------------------------
       2    A319-100   V2524-A5   Dec-98        38.0
  ---------------------------------------------------
       3    A319-100   V2524-A5   Dec-98        38.0
  ---------------------------------------------------
       4    A319-100   V2524-A5   Jul-99        40.6
  ---------------------------------------------------
       5    A319-100   V2524-A5   Jul-99        40.6
  ---------------------------------------------------
       6    A319-100   V2524-A5   Aug-99        40.6
  ---------------------------------------------------
       7    A320-200   V2527-A5   Feb-99        45.5
  ---------------------------------------------------
       8    A320-200   V2527-A5   May-99        46.2
  ---------------------------------------------------
</TABLE>
 
GENERAL MARKET OVERVIEW
 
     For the third consecutive year, orders surpassed deliveries. There were a
record number of gross jet aircraft orders in 1997 as 1,392 aircraft were put on
firm order against 652 deliveries. Orders outpaced deliveries across almost all
seat classifications and deliveries for 1997 outpaced 1996 deliveries by almost
a third. Operators are continuing the trend of increasing their order books to
ensure future delivery positions in an expanding market. The order backlog for
jet aircraft at the end of 1997 is close to 3,100 aircraft. With the record
setting backlogs, Boeing and Airbus, notwithstanding their competitive slugfest,
may soon see some ability to raise prices as new customers for aircraft may have
to pay a premium to obtain aircraft positions in the manufacturers' busy
production lines.
 
     The strong aircraft order activity is in line with robust traffic and solid
economic growth and prosperity that began in earnest in 1993. The world's
airlines are now in their fifth consecutive year of positive earnings as a
result of increased traffic. While passenger yields have continued to decline
somewhat, strong traffic coupled with relatively flat unit costs and low
capacity increases have produced solid profitability. Load factors for the
industry are now at all time high levels.
 
     Aircraft order and the resultant delivery activity correlate well with
overall economic activity and the business cycle. The extended period of
economic growth that occurred in the late 1980s led to rising traffic
                                     A-II-3
<PAGE>   98
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
demand, which was met by the airlines through a record number of aircraft orders
at favorable financing terms. The order book backlog peaked at 2,900 jetliners
in 1990, triple the previous peak that occurred in 1979.
 
     By late 1990, however, it was obvious that a mismatch between unit revenue
and unit costs was occurring. Unit costs in 1990 exceeded 1989 levels by almost
10% while yields increased by less than 5%. Adding to this situation was the
fact that several regional economies were falling into recession and the Gulf
War had broken out causing fuel prices to spike. Demand for air travel fell just
as the world's airlines began taking delivery of the record number of aircraft
that were ordered in the previous two to three years. The downward spiral had
begun and between 1990 and 1993, the world's airlines lost over $20 billion. The
Figure below summarizes the order and delivery pattern of aircraft over the last
25 years.
 
   FIGURE 2
 
                                 COMMERCIAL JET
                       NEW ORDERS, DELIVERIES AND BACKLOG
                                  1970 TO 1997
 
<TABLE>
<CAPTION>
                             DELIVERIES      NEW ORDERS        BACKLOG
<S>                         <C>             <C>             <C>
1970                             318             204             463
1971                             233             136             366
1972                             215             275             426
1973                             283             257             400
1974                             317             273             356
1975                             285             173             244
1976                             234             242             252
1977                             191             328             389
1978                             259             684             814
1979                             399             544             959
1980                             433             359             885
1981                             426             274             733
1982                             284             197             646
1983                             311             224             559
1984                             263             357             653
1985                             343             624             934
1986                             395             666            1205
1987                             414             597            1388
1988                             508            1031            1911
1989                             564            1280            2627
1990                             665             911            2873
1991                             835             448            2486
1992                             785             407            2108
1993                             641             341            1808
1994                             517             426            1717
1995                             473             736            1980
1996                             495            1208            2520
1997                             631            1053            2970
</TABLE>
 
                Source: Back Aviation Services and Avitas calculations
 
                                     A-II-4
<PAGE>   99
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
     AVITAS's view today is that the economic equation surrounding the supply of
seats vs. the demand for travel as well as the relationship between unit revenue
and unit costs is in better balance. This "economic balance" has produced
sustained profitability over the last four years. World passenger traffic for
1997 was up more than 30% over the level experienced in 1993. At the same time,
seat capacities have grown roughly 20%, raising load factors in the process to
record levels. Moreover, unit costs have remained flat reducing passenger
breakeven load factors. Cargo movements have also increased contributing to
overall airline profitability.
 
     Air passenger and air freight growth are positively correlated with general
economic activity as measured by Gross National Product and are a multiple of
real GNP growth rate changes. Sustained increases in traffic translate into new
aircraft order activity to meet passenger and cargo demands. For example, the
U.S. economy has grown at an annual rate of 2.6% between 1992 and 1997 while
passenger traffic has increased at a yearly rate of 5.2%. For that period, the
U.S. major carriers have produced operating profits of over $13 billion. With
the economy forecast to grow at an annual rate of approximately 2.5% over the
next several years, we envision traffic and thus aircraft orders to continue at
a steady pace to meet growth and fleet renewal plans. Figure 3 indicates the
relationship between changes in the U.S. GNP and changes in revenue passenger
miles over the last 16 years.
 
     While the U.S. economy has produced steady growth over the last several
years, other regional economies are having some difficulties. Asia is currently
in the news with reports of economic retrenchment and currency devaluation.
Given the seriousness of the current situation and the importance of that region
for future aircraft deliveries and values, please see a separate section on the
Asian Crisis for a fuller discussion.
 
                                     A-II-5
<PAGE>   100
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
FIGURE 3
GNP AND U.S. AIRLINE RPMS GRAPH
 
<TABLE>
<CAPTION>
                                                     REAL GNP                U.S. RPMS
<S>                                           <C>                      <C>
1980                                                   -0.2                     -3.9
1981                                                    1.8                     -2.9
1982                                                   -2.1                      4.8
1983                                                      4                        8
1984                                                      7                      8.5
1985                                                    3.6                      9.9
1986                                                    3.1                      7.9
1987                                                    2.9                     10.3
1988                                                    3.8                      4.7
1989                                                    3.4                      2.2
1990                                                    1.2                      5.5
1991                                                   -0.9                     -1.9
1992                                                    2.7                      6.6
1993                                                    2.3                      2.5
1994                                                    3.5                      6.2
1995                                                      2                        4
1996                                                    2.4                      6.6
1997E                                                   3.7                      5.3
</TABLE>
 
Source: Airline Monitor, AVITAS estimates
 
     In September 1997, Boeing gained approval from the European Commission for
its merger with McDonnell Douglas by dropping exclusivity contracts with
American Airlines, Delta Air Lines, and Continental Airlines. Airbus has also
been active in gaining market share by achieving large orders with US Airways
and Northwest Airlines. In any consolidating industry, questions about higher
prices are always prevalent. Indeed, many observers are trying to determine what
will happen to aircraft pricing with one less major supplier. From the airlines'
view however, they benefit from operating a "family" of aircraft where they
achieve larger pricing discounts from the manufacturers. They also obtain cost
savings through aircraft commonality, particularly in crew training and
maintenance.
 
     Boeing has had difficulty in ramping up to an aggressive production level
and consequently, in delivering new aircraft on schedule. This has been a result
of supply chain problems and shortages in capacity from vendor related parts.
These difficulties may not be resolved until the middle of 1998. To
 
                                     A-II-6
<PAGE>   101
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
help unravel these issues, Boeing closed the production lines for the B747 and
B737 for a month. As a result of the delivery delays, Boeing has taken a charge
of $1.6 billion (pretax) that resulted in a net loss of $696 million for the 3rd
quarter of 1997. The B747 models may see lingering delivery delays that may last
into 1999.
 
     Boeing has decided to end production of the Douglas inherited MD-80 and
MD-90 aircraft when commitments end in 1999 and recently announced plans to end
production of the MD-11 in 2000. It plans to keep the MD-95 program (now renamed
the Boeing 717) and build the fifty B717 aircraft ordered by AirTran Airlines
but the aircraft will likely be reduced in size in the future to between 80 and
100 seats so that Boeing can better compete in that seat category. Figure 4
represents the order and delivery activity that has taken place through 1997 by
seat classification.
 
FIGURE 4
AIRCRAFT ORDERS AND DELIVERIES
 
<TABLE>
<CAPTION>
                                                     ORDERED                 DELIVERED
<S>                                           <C>                      <C>
50-70 SEATS                                            224                       55
100 SEATS                                               38                       21
150 SEATS                                              381                      169
200 SEATS                                               69                       60
250 SEATS                                               72                       34
300 SEATS                                               83                       90
400 SEATS                                               24                       37
</TABLE>
 
Source: Airline Monitor, Boeing, Airbus, AVITAS estimates
 
                                     A-II-7
<PAGE>   102
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
  50-70 seats (Regional jets)
 
     The regional jet has become one of the hottest selling aircraft the
industry has seen in some time. These 50-seat small jets are changing the
competitive landscape in the regional industry. They have the ability to perform
hub-raiding missions into thin markets and capture traffic from competitors'
formerly captive markets. American Eagle placed orders for 42 Embraer 145s in
June. This order, coupled with Continental's take-up of 25 options on top of
their original order of 25 aircraft, has allowed Embraer to challenge the
Canadair RJ and become a viable competitor in this sector. The CRJ now has over
300 firm orders while the EMB-145 has close to 200. The backlogs for both of
these aircraft are strong with a total of 255 yet to be delivered. The emergence
of the EMB-145 will hold regional jet prices at a competitive level and further
stimulate regional jet sales. The CRJ-700, a seventy-seat stretched version of
the CRJ, was launched with an order from American Eagle for 25 aircraft. Smaller
regional jets are also on the horizon as both Fairchild Dornier and Embraer will
be producing 32 and 37 seat jets respectively. Each of these products will be
attempting to capitalize on the U.S. regional industry's strong desire for jet
aircraft. The activity on the regional jet front has produced some fallout,
however, as the AIR organization announced that it has cancelled its yet to be
launched AIRJet program, which included the 58-seat AIR-58, the 70-seat AIR-70,
and the 84-seat AIR-80.
 
  100 Seats
 
     In this sector, the demand for aircraft is strong and most aircraft seem to
be trading above the intrinsic or Base Values. In particular, DC-9-30 and B737
aircraft are experiencing very firm market conditions. New orders in this seat
segment are showing some relative weakness, however, as the backlog has fallen.
Most airlines are watching developments at Boeing and its plans for the B717 as
well as Airbus and its development with its Chinese aerospace partners on the
AE-316/317. The B737-600 series has recorded 40 orders through 1997.
 
  150 Seats
 
     This has been the most active segment for new aircraft orders.
Consequently, the backlog has grown considerably as Boeing and Airbus virtually
split the 592 orders that have occurred in 1997 for the Airbus 319/320 and the
Boeing 737-300/400/700/800 series. With 203 deliveries in 1997, the backlog grew
by 389 aircraft. This segment is most active as a result of operators
positioning themselves for new aircraft as they formulate plans to retire some
of the older 727 aircraft in service. Still, many operators are committed to
their 727 fleets.
 
  200 Seats
 
     While this segment pales in comparison to the activity as registered at 150
seats, it had solid growth in both new orders and deliveries. The B757-200 and
the A321 dominate activity gaining 95 new orders in 1997. Boeing has launched a
stretch of the B757 line with the B757-300 with an initial order of 12 aircraft
from charter operator Condor Flugdienst. Since that order, however, only 2
additional orders for the -300 model aircraft have materialized in 1997.
 
                                     A-II-8
<PAGE>   103
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
  250 Seats
 
     For some aircraft types, such as the DC-10, the market has improved as both
United and American have committed their DC-10-10s to FedEx. However, any stored
L-1011s are unlikely to return to service. We do see more freighter conversion
of A300s, which should further improve the supply situation for freighters. With
the launch of the Airbus A330-200, the dominance of the Boeing 767 is being
contested. To that end, the A330-200 in 1997 had slightly more orders than the
perennial favorite 767-300 aircraft. Both the A300 and A310 have weak backlogs
putting the future of those programs in question as Airbus turns up its
marketing efforts on the A330 series.
 
  300 Seats
 
     Boeing launched the 767-400ERX aircraft which has the same range as the
767-300 but with about 15% more capacity. First deliveries are scheduled in
early 2000. Older Boeing 747s are being retired and the market continues to be
strong as Boeing 777s and Airbus A340s replace them. Recently Boeing announced
plans to discontinue production of the MD-11 in year 2000 because of
insufficient demand for the wide-body aircraft. Delta Airlines' and Continental
Airlines' orders for B767-400s impedes Airbus's efforts to penetrate the U.S.
market with the A330.
 
  400 Seats
 
     Airbus announced a $2.9 billion development effort on the A340 program to
launch new models of the series: the -500 and -600 models. The new models are to
compete with Boeing who has long dominated the high capacity end of the market.
The A340-600 will have a seating capacity of 380 compared with 295 on the
current largest Airbus model. The longer range A340-500 will have 313 passengers
and will have a range of 8,500 nautical miles. Deliveries would start in early
2002. Airbus is still looking for launch customers for the A3XX super-jumbo
aircraft but nevertheless is still hopeful for a launch decision by the end of
1998. For its part, Boeing has slowed design work for longer-range versions of
its 777 series as a result of lack of orders. Boeing has seen its backlog stay
virtually even on the 747-400 aircraft as it delivered 39 aircraft in 1997
against 37 orders. Moreover, the 747-400 line has been affected by the
previously mentioned supply chain difficulties, which could trail into 1999.
 
THE ASIAN CRISIS
 
     The economic difficulty following currency devaluations in Asia has brought
about serious implications for aircraft values likely to last through the
changeover to the next millennium. However, the economies of the United States
and the rest of the world are strong and AVITAS believes that the Asian crisis
will certainly reduce the world rate of economic growth, but it will not
precipitate a global recession. Aircraft values are likely to suffer during this
crisis, the most concern is for widebody passenger aircraft values. Narrowbody
values are better protected because Asia is not a large center of demand.
Thirty-two percent of the world's widebody aircraft are in the possession of
Asian carriers, and Asian carriers have 29% of the world's firm orders for
widebodies. Many of these carriers, particularly in Indonesia are suffering
severe revenue losses from reduced traffic levels and civil strife.
 
                                     A-II-9
<PAGE>   104
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
     Thailand, Malaysia, South Korea and Indonesia have had their currencies
devalue over 40% against the U.S. dollar. Indonesia's rupiah has lost up to 70%
of its value compared to the US dollar and the crisis is expected to worsen.
Indonesia in a "best-case" scenario will experience a 15% drop-off in economic
activity. South Korea's problems are considerably less explosive, yet the
expectation is that the country will experience economic decline of about 4%.
Malaysia's economy has historically been more resilient to economic corrections;
however, MAS, the country's premier carrier has experienced a severe shortage of
capital. MAS has deferred deliveries of 747-400s and the carrier is unable to
finance its Boeing 777 deliveries. A recent attempt to sell its four 777
deliveries to Delta Air Lines has failed at the deal table. Thai International
announced a $578 million loss for the Fourth Quarter of 1997. The massive loss
was considered to be entirely due to foreign currency provisions.
 
     Making predictions for the Asia-Pacific region will be difficult in the
coming months as the situation remains volatile. AVITAS believes that
expectations hinge on Japan and China's actions. In comparison of the region,
Japan's GDP far exceeds those of the other Asian countries. Japan is the
region's largest trading partner and provider of investment funds. Japan's
extensive inter-relation with the other economies of the region has only served
to worsen the problem. The yen recently fell to an eight-year low against the
U.S. dollar, driving down the prices of stocks and currencies. Japanese outbound
leisure travel has sharply declined, further affecting other economies in the
region that depend heavily on Japanese tourism dollars, especially Hong Kong and
Singapore. The Federal Reserve has intervened to keep the dollar between 130 and
140 yen. The expectation is that if the yen were to fall more and head toward
150 to the dollar, the Chinese would devalue the yuan, setting off another chain
reaction of devaluation for the other Asian countries.
 
     Officials from China have stated that they forecast a growth in their
economy of 8% for 1998. AVITAS is of the opinion that 5% is even too optimistic.
In addition to poor operating performance for Chinese airlines, debt levels are
at a critically high level. At present, only six of China's airlines are even
capable of showing a profit. They are the six largest: Air China, China
Southern, China Eastern, China Northern, China Southwest, and China Northwest.
Whether they will show a profit for 1998 still remains to be seen, but at
present is probably unlikely. Airlines that have practiced price-cutting to fill
seats have experienced heavy losses. These airlines already had much more
capacity than what was required for their expected growth. China Eastern, which
showed a profit in 1997, has shown a First Quarter 1998 loss of 240 million yuan
(about $29 million U.S. dollars). Air China and China Southern were even deeper
in the red for the First Quarter at an estimated loss of 600 million yuan (about
$72 million U.S. dollars). All of China's principal airlines are currently
exploring sale-leasebacks to raise much needed capital; however, the majority of
China's new aircraft are already heavily financed, and getting an advantageous
deal for an older aircraft may be extremely difficult as the credit ratings of
the Chinese carriers fall. Lessors will only consider sale-leaseback
arrangements with Chinese carriers that are acknowledged to be long-term players
with Chinese government protection.
 
     The picture is not as bleak for other carriers in the region. Qantas
Airways expects that revenues will continue to hold up despite the downturn in
traffic for the region. The Australian airline should have enough resources to
meet the debt repayment and capital expenditure requirements of their new
deliveries. A wide spread of international routes and substantial internal cash
reserves should generate the necessary
 
                                     A-II-10
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AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
cash flow to see them through the decline in Asian traffic. Qantas' Asian routes
make up only 20% of total revenue passenger kilometers (excluding Japan). By
implementing rapid changes in their scheduling, Qantas has been able to keep
their load factors from deteriorating. Flights from Japan were withdrawn while
simultaneously increasing flights to the Philippines to take advantage of PAL's
worsening situation.
 
     The strike-ravaged Philippine Airlines have been frantically attempting to
dispose of aircraft to stave-off closure. As of June 1998, PAL is in default for
deferring the delivery of three 747-400 aircraft and they are expected to have
to defer the other three that they have on order as well. Also in June of 1998,
Qantas is expected to take delivery of two 767-300ER aircraft, which will be
purchased using cash reserves. It is expected that they will be able to obtain a
lease-structured financing for the aircraft. Qantas is expected to take delivery
of three 747-400 aircraft in October 1999 and April 2000.
 
     Deferrals by the Asian carriers have global implications for aircraft
values. A potential buildup of undelivered aircraft will soften aircraft values.
There will be an opportunity for carriers from other regions to snatch up
aircraft at reduced prices, but the ability of the market to absorb large
numbers of high-valued widebody aircraft will be challenged in some aircraft
markets. Under the fairly firm market conditions that exist in the United
States, the remarketing period for a widebody commercial aircraft is about six
months, but under glut market conditions remarketing time would be lengthened
considerably, and would result in many aircraft being parked.
 
     AVITAS believes that conditions so far indicate that the recession in Asia
will last for about two years and will have a negative affect on widebody
aircraft values during this period, but we are not likely to experience the
severity of conditions seen in the 1990 recession. The economies of the rest of
the world are strong, and a worldwide recession is an unlikely scenario. Europe
and Latin America are experiencing solid economic growth and are expected to
remain stable as long as the United States avoids a recession. From a world
economic viewpoint, the Asian crisis is reducing the rate of growth for the
world economy and consequently aircraft demand forecasts will need to be
moderately adjusted.
 
BACKGROUND AIRBUS A319
 
     The A319 Program was launched in June, 1993 and the first aircraft of the
type was certificated in April 1996. The aircraft seats 124 passengers in a
typical two-class configuration or 154 in a maximum configuration. It has a
basic range of 2,000 nautical miles with a MTOW of 141,100 lb and an optional
range of 3,000 nautical miles with a MTOW of 149,900 lbs. The A319 has a 12-feet
shorter fuselage than the A320 accomplished by removing two fuselage plugs.
 
     The design of this new aircraft is focused on maintaining a high degree of
commonality with the A320 and the A321 so that an existing A319 operator could
easily transition to its larger versions, where almost all of the major systems
of the A319 are exactly the same.
 
     The A319 is available with either CFM56-5A or IAE V2500-A5 engine and meets
the noise abatement requirements outlined in U.S. FAR Part 36, Stage 3, and ICAO
Annex 16, Chapter 3 regulations.
 
                                     A-II-11
<PAGE>   106
 
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AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
CURRENT MARKET -- AIRBUS A319
 
  Current Market
 
     AVITAS believes that A319 current market is firm as is the narrowbody
market as a whole. With a backlog of 371 firm orders and acceptance in the North
American market, the A319 values should remain firm for the foreseeable future.
 
  Historic Market Development
 
     The development of the A319, A320, and A321 characterizes the market
strategy of Airbus to build an entire family of aircraft capable of
accommodating a wide range of travel demands while maintaining a high degree of
commonality. Operators that have a mixed fleet of A319, A320s and A321s will a
have greater ability to match capacity to demand, reduce operating cost,
increase crew productivity and simplify ground handling. This is shown by the
fact that the majority of all current operators of A319 aircraft or with A319
aircraft on order are present A320 customers.
 
  The Operating Lease Market
 
     AVITAS is aware of lease rates for 1996 year of manufacture A319-100s for
$310,000 per month per aircraft on 10-year operating leases with lessor's cost
of $34.5 million per aircraft.
 
  Availability
 
     AVITAS is not aware of any used aircraft available. This is in line with
expectations for such a new aircraft program.
 
  Recent Transactions
 
     With the recent introduction of the A319, a secondary market has yet to
develop for this aircraft.
 
  Engine Choices
 
     The current A319 fleet is powered by CFM56-5A/-5B engines (86%) and IAE
V2500-A5 (14%). However, in the broader scope of the A320 family, 63% are
operated with CFM engines and 37% with IAE engines.
 
  Recent Fleet Developments
 
     Air France announced in June, 1998 that it has placed orders for 16 A319
aircraft, with deliveries beginning in 2002. In March, 1998, the three Latin
American carriers TAM of Brazil, TACA Group and LanChile combined to order 90
A319 and A320 aircraft with options for an additional 89 aircraft. Breakdown of
the order between A319 and A320 aircraft was not announced, however the aircraft
will be powered by IAE V2500 engines. Also in March, United Airlines signed a
firm contract to purchase 10 A319 aircraft, for delivery in 2000 and 2001.
Spanish flag carrier Iberia signed a MOU with Airbus in February, 1998 for
orders and options of up to nine A319 aircraft as part of a larger deal
involving the firm
 
                                     A-II-12
<PAGE>   107
 
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AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
order of 50 A319/A320/A321 aircraft and options for 26 additional aircraft.
Northwest has announced an order for 50 firm and 100 option A319 aircraft to be
delivered between 1999 and 2003. In November last year, US Airways affirmed its
order for 400 A319/A320/A321 aircraft. The carrier plans to take delivery of 234
aircraft in 1998. The Airbus fleet is to replace the carriers DC-9-30s,
B737-200s and MD-80s.
 
     Tunis Air recently announced an order for three A319s and Finnair is
replacing its DC-9-50 fleet with five A319s, three A320s and four A321s.
 
                                     A-II-13
<PAGE>   108
 
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AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
  Current Operator Base and Backlog
 
     Presented below is the current fleet and backlog for the A319-100 by
operator. Also presented are the A319 by engine type and a presentation of the
A319/A320/A321 family current fleet and backlog.
 
FIGURE 5
                                A319 FLEET DATA
                                AS OF JUNE 1998
 
<TABLE>
<CAPTION>
- -----------------------------------------------------------------------------------------------------------------
                   OPERATOR                        IN SERVICE           ORDERS          OPTIONS         TOTAL
- -----------------------------------------------------------------------------------------------------------------
<S>                                            <C>                 <C>              <C>              <C>
  AIR CANADA                                                  33               --               --             33
- -----------------------------------------------------------------------------------------------------------------
  LUFTHANSA                                                   17                2               20             39
- -----------------------------------------------------------------------------------------------------------------
  AIRBUS INDUSTRIE                                            10               --               --             10
- -----------------------------------------------------------------------------------------------------------------
  AIR FRANCE                                                   9                4                8             21
- -----------------------------------------------------------------------------------------------------------------
  UNITED AIR LINES                                             9               25               --             34
- -----------------------------------------------------------------------------------------------------------------
  SWISSAIR                                                     8               --               --              8
- -----------------------------------------------------------------------------------------------------------------
  TAP AIR PORTUGAL                                             4               12               --             16
- -----------------------------------------------------------------------------------------------------------------
  EUROWINGS                                                    3                1                2              6
- -----------------------------------------------------------------------------------------------------------------
  CROATIA AIRLINES                                             1                4                6             11
- -----------------------------------------------------------------------------------------------------------------
  AMERICA WEST AIRLINES                                       --               22               20             42
- -----------------------------------------------------------------------------------------------------------------
  FINNAIR                                                     --                5                5             10
- -----------------------------------------------------------------------------------------------------------------
  GE CAPITAL AVIATION SERVICES INC.                           --                2                4              6
- -----------------------------------------------------------------------------------------------------------------
  IBERIA                                                      --               --                9              9
- -----------------------------------------------------------------------------------------------------------------
  ILFC                                                        --               42               --             42
- -----------------------------------------------------------------------------------------------------------------
  LAN CHILE                                                   --               11                9             20
- -----------------------------------------------------------------------------------------------------------------
  NORTHWEST AIRLINES                                          --               50              100            150
- -----------------------------------------------------------------------------------------------------------------
  SABENA                                                      --               26               --             26
- -----------------------------------------------------------------------------------------------------------------
  SILKAIR                                                     --                3               --              3
- -----------------------------------------------------------------------------------------------------------------
  TACA INTERNATIONAL AIRLINES                                 --               21               18             39
- -----------------------------------------------------------------------------------------------------------------
  TAM TRANSPORTES AEREOS REGIONAIS                            --               25               25             50
- -----------------------------------------------------------------------------------------------------------------
  TUNIS AIR                                                   --                3               --              3
- -----------------------------------------------------------------------------------------------------------------
  UNKNOWN OPERATOR                                            --                4               --              4
- -----------------------------------------------------------------------------------------------------------------
  US AIRWAYS                                                  --              109              276            385
- -----------------------------------------------------------------------------------------------------------------
  GRAND TOTAL                                                 94              371              502            967
</TABLE>
 
                                     A-II-14
<PAGE>   109
 
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AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
Source: BACK Information Services
 
FIGURE 6
 
<TABLE>
<CAPTION>
 
                                 A319-100 AIRCRAFT BY ENGINE MANUFACTURER
                                             AS OF JUNE 1998
- ----------------------------------------------------------------------------------------------------------
 ENGINE                                                     IN SERVICE    ORDERS    OPTIONS    TOTAL
- ----------------------------------------------------------------------------------------------------------
<S>                                                        <C>            <C>       <C>        <C>     <C>
 CFM 56                                                         81         222        430       733
- ----------------------------------------------------------------------------------------------------------
 V2500                                                          13         116         72       201
- ----------------------------------------------------------------------------------------------------------
 Undecided                                                      --          33         --        33
- ----------------------------------------------------------------------------------------------------------
 GRAND TOTAL                                                    94         371        502       967
</TABLE>
 
Source: BACK Information Services
 
FIGURE 7
 
<TABLE>
<CAPTION>
 
                             A319/A320/A321 SERIES CURRENT FLEET AND BACKLOG
                                             AS OF JUNE 1998
- ---------------------------------------------------------------------------------------------------------
 MODEL                                                     IN SERVICE    ORDERS    OPTIONS    TOTAL
- ---------------------------------------------------------------------------------------------------------
<S>                                                       <C>            <C>       <C>        <C>     <C>
 A319-100                                                      94         371        502        967
- ---------------------------------------------------------------------------------------------------------
 A320-100                                                      18          --         --         18
- ---------------------------------------------------------------------------------------------------------
 A320-200                                                     631         344        136      1,111
- ---------------------------------------------------------------------------------------------------------
 A321-100                                                      74          34         64        172
- ---------------------------------------------------------------------------------------------------------
 A321-200                                                      28          87         34        149
- ---------------------------------------------------------------------------------------------------------
 GRAND TOTAL                                                  845         836        736      2,417
</TABLE>
 
Source: BACK Information Services
 
  Outlook and Future Asset Risk Analysis
 
     The A319 competes with the Boeing 737-500 and -600 which currently have
combined 368 aircraft in service and 154 on order.
 
     It is AVITAS's opinion that expansion of the A319's operator base will
primarily come from existing A320 operators. Of minor concern is that 12% of the
current backlog is held by GE Capital Aviation Services (GECAS) and
International Lease Finance Corporation (ILFC) who have likely ordered the
aircraft with the flexibility to convert to A320 or A321 aircraft.
 
                                     A-II-15
<PAGE>   110
 
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AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
BACKGROUND -- AIRBUS A320 SERIES
 
     The A320, a stage 3 compliant short to medium range twin-engine jetliner
was launched in 1984 with certification in 1988. The original was the A320-100,
of which there are only 18 in service among three operators. The  -- 100
aircraft have no wing center tank which limits the range and payload.
 
     The A320-200 was first flown and delivered in 1988 to Air France and
British Caledonian Airways. Its typical configuration includes a two-person
cockpit crew with capacity for 150 passengers with high density seating of 179.
The A320 has a range of 3,000 nautical miles with 150 passengers and is powered
by CFM56-5A1/-5A3, V2500-A1/A5 and V2527-A5 engines, with thrust ranging from
25,000 lbs to 26,500 lbs. The maximum takeoff weight (MTOW) ranges from 162,000
lbs to 169,750 lbs. A technically advanced aircraft, the A320 includes such
design concepts as fly-by-wire flight controls, centralized maintenance
reporting system, side stick controllers in the cockpit and the use of composite
materials in the major elements of primary structures including the horizontal
and vertical stabilizers.
 
     The A320 has a common type rating with the A319 and the A321, which means
that they can be operated as one aircraft type and with identical maintenance
procedures.
 
CURRENT MARKET -- AIRBUS A320-200
 
  Current Market
 
     AVITAS is of the opinion that the current market for the Airbus A320 series
aircraft is firm. This is evidenced by a low level of availability and high
demand for the type, which AVITAS attributes to a general resurgence in the
Stage III narrowbody aircraft market.
 
  Historic Market Development
 
     The A320 market had been very soft during the early 1990s with an excess
supply of new aircraft being delivered into a depressed market. This was caused
not only by bankruptcies of several carriers with A320s on order, but also by
the speculative buying of A320s by leasing companies. During 1994 and 1995, the
market for the aircraft firmed substantially. Only four A320 aircraft were
reported as available for sale or lease in October 1997, compared to between 14
and 17 during 1994 and 1995.
 
  The Operating Lease Market
 
     During the late 1980s, operating lessors, primarily GPA, GATX, ILFC,
Kawasaki and Orix placed orders for a significant amount of A320 aircraft for
early 1990 deliveries. Unfortunately, the aircraft were delivered during the
soft market of the early 1990s and were placed at lease rates that were at times
less than $200,000 per month. During the last couple of years, the excess A320
capacity had been placed with riskier credits such as the U.S. start-up Midway
Airlines at rates in the $235,000 per month range. Lately, the A320 lease market
has strengthened resulting in rentals at the $300,000 per month level or above.
AVITAS is aware of several new aircraft leases in the $330,000 range and one
1992 vintage aircraft being negotiated at just below $300,000 per month.
 
                                     A-II-16
<PAGE>   111
 
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AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
  Availability
 
     As of June 1998, twelve A320-200s are advertised as available for sale or
lease. ORIX Aviation Systems is offering five 1992/1993 vintage aircraft for
sale or lease. Transaer International Airways has four available for 6-12 month
ACMI leases. Onur Air and Caledonian Airways have aircraft available for wet
lease.
 
  Recent Transactions
 
     Oasis International Leasing recently acquired six A320s operated by Gulf
Air in a sale-leaseback transaction. The six aircraft are 1992-1993 vintages and
were purchased for an average price of $32.5M each. TACA recently took delivery
of two new A320-200 aircraft in a sale and leaseback transaction in which the
lessor paid $41.14 million for each aircraft. Debis Airfinance has been active
in this market in late 1997 purchasing a 1992 vintage A320 from ILFC. Most of
the transactions that have been occurring over the past year have been leases or
sales with leases attached.
 
  Operator Base and Backlog
 
     As of June 1998, there are 631 aircraft in service among 74 operators and
344 on firm order. Displayed below are the ten largest operators and ten largest
orderholders for the A320-200.
 
            FIGURE 8
                         A320-200 TEN LARGEST OPERATORS
                                AS OF JUNE 1998
 
<TABLE>
<CAPTION>
- --------------------------------------------------------------------------------
                                                                 AIRCRAFT IN
                         OPERATORS                                 SERVICE
- --------------------------------------------------------------------------------
<S>                                                          <C>
  NORTHWEST AIRLINES                                                 56
- --------------------------------------------------------------------------------
  AIR FRANCE                                                         45
- --------------------------------------------------------------------------------
  UNITED AIR LINES                                                   44
- --------------------------------------------------------------------------------
  AIR CANADA                                                         34
- --------------------------------------------------------------------------------
  LUFTHANSA                                                          33
- --------------------------------------------------------------------------------
  AMERICA WEST AIRLINES                                              30
- --------------------------------------------------------------------------------
  INDIAN AIRLINES CORPORATION                                        30
- --------------------------------------------------------------------------------
  IBERIA                                                             22
- --------------------------------------------------------------------------------
  ALL NIPPON AIRWAYS                                                 21
- --------------------------------------------------------------------------------
  ANSETT AIRLINES                                                    20
</TABLE>
 
            Source: BACK Information Services
 
                                     A-II-17
<PAGE>   112
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
            FIGURE 9
                       A320-200 TEN LARGEST ORDERHOLDERS
                                AS OF JUNE 1998
 
<TABLE>
<CAPTION>
- --------------------------------------------------------------------------------
                                                                 AIRCRAFT IN
                         OPERATORS                                 SERVICE
- --------------------------------------------------------------------------------
<S>                                                          <C>
  IBERIA                                                             31
- --------------------------------------------------------------------------------
  INTERNATIONAL LEASE FINANCE CORP.                                  28
- --------------------------------------------------------------------------------
  GE CAPITAL AVIATION SERVICES INC.                                  25
- --------------------------------------------------------------------------------
  UNITED AIR LINES                                                   25
- --------------------------------------------------------------------------------
  AMERICA WEST AIRLINES                                              24
- --------------------------------------------------------------------------------
  ALITALIA                                                           19
- --------------------------------------------------------------------------------
  TACA INTERNATIONAL AIRLINES                                        16
- --------------------------------------------------------------------------------
  US AIRWAYS                                                         15
- --------------------------------------------------------------------------------
  TAM TRANSPORTES AEREOS REGIONAIS                                   13
- --------------------------------------------------------------------------------
  NORTHWEST AIRLINES                                                 12
</TABLE>
 
            Source: BACK Information Services
 
     Presented below is the A320 current fleet and backlog by engine type.
 
FIGURE 10
                A320-200 CURRENT FLEET & BACKLOG BY ENGINE TYPE
                                AS OF JUNE 1998
 
<TABLE>
<CAPTION>
- ------------------------------------------------------------------------------------------------------------------
           ENGINE TYPE                 IN SERVICE            ORDERS              OPTIONS              TOTAL
- ------------------------------------------------------------------------------------------------------------------
<S>                                <C>                 <C>                 <C>                 <C>
  CFM56-5                                        384                 178                  39                   601
- ------------------------------------------------------------------------------------------------------------------
  V2500                                          247                 139                  95                   481
- ------------------------------------------------------------------------------------------------------------------
  Unknown                                                             27                   2                    29
- ------------------------------------------------------------------------------------------------------------------
  GRAND TOTAL                                    631                 344                 136                 1,111
</TABLE>
 
Source: BACK Information Services
 
     Additionally, combined with the other members of the Airbus narrowbody
family, the A319 and A321, the current fleet for the A320 family amounts to 845
aircraft and 836 firm orders.
 
                                     A-II-18
<PAGE>   113
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
  Recent Fleet Developments
 
     In March this year, the second largest order ever for Airbus was placed
jointly by LanChile, the TACA Group and TAM for 90 firm orders and 89 options of
the A320 and the A319 aircraft.
 
     Iberia of Spain announced earlier this year an order for 50 firm and 26
options from the Airbus family, specifically 36 A320s, 31 A321s and 9 A319s. The
order is part of Iberia's fleet standardization program.
 
     In November 1997, US Airways affirmed its order for 400 A319/A320/A321
aircraft. The carrier plans to take delivery of 234 aircraft in 1998. The Airbus
fleet is to replace the carriers DC-9-30s, B737-200s and MD-80s.
 
  Outlook and Future Asset Risk Analysis
 
     AVITAS believes that the A320 will continue to be a significant competitor
in the 150-seat market well into the future with competition from the Boeing
737-400 and the 737-800 with 30 and 384 firm orders, respectively. The A320 has
more range than the 737-400 and slightly higher seat capacity, the 737-800
however, fares better than the -400 with a range capacity of 2,900 nautical
miles and increased seat capacity by 17 seats.
 
     With a well established population of 631 A320-200 aircraft currently in
service among 74 operators, and 344 on firm order scheduled for delivery
throughout the year 2005, the future market base for the type is due to expand
significantly with residual values developing positively.
 
COVENANTS
 
     Unless otherwise noted, the values presented in this report assume an
arm's-length, free market transaction for cash between informed, willing and
able parties free of any duress to complete the transaction. If a distress sale
becomes necessary, a substantial discount may be required to quickly dispose of
the equipment.
 
     AVITAS does not have, and does not intend to have, any financial or other
interest in the subject aircraft. Further, this report is prepared for the
exclusive use of the Client and shall not be provided to other parties without
the express consent of the Client.
 
     This report represents the opinion of AVITAS and is intended to be advisory
only in nature. Therefore, AVITAS assumes no responsibility or legal liability
for any action taken, or not taken, by the Client or any other party, with
regard to this equipment. By accepting this report, all parties agree that
AVITAS shall bear no such responsibility or legal liability including liability
for special or consequential damage.
 
                                     A-II-19
<PAGE>   114
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
AMERICA WEST AIRLINES                                         SEPTEMBER 24, 1998
 
STATEMENT OF INDEPENDENCE
 
     AVITAS hereby states that this valuation report has been independently
prepared and fairly represents AVITAS's opinion of the subject aircraft's value.
 
/s/ Noel Petrie
- ------------------------------------------------
Noel Petrie
Manager -- Asset Valuation
 
                                     A-II-20
<PAGE>   115
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
                    APPENDIX A -- AVISTAS VALUE DEFINITIONS
 
     - BASE VALUE is the appraiser's opinion of the underlying economic value of
       an aircraft in an open, unrestricted, stable market environment with a
       reasonable balance of supply and demand and assumes full consideration of
       its "highest and best use." An aircraft's Base Value is founded in the
       historical trend of values and in the projection of value trends and
       presumes an arm's-length, cash transaction between willing and
       knowledgeable parties, acting prudently, with an absence of duress and
       with a reasonable period of time for marketing. Base Value typically
       assumes that an aircraft's physical condition is average for an aircraft
       of its type and age, and its maintenance time status is at mid-life,
       mid-time (or benefiting from an above-average maintenance status if it is
       new or nearly new).
 
     - MARKET VALUE (or CURRENT MARKET VALUE if the value pertains to the time
       of the analysis) is the appraiser's opinion of the most likely trading
       price that may be generated for an aircraft under the market conditions
       that are perceived to exist at the time in question. Market Value assumes
       that the aircraft is valued for its highest, best use, that the parties
       to the hypothetical transaction are willing, able, prudent and
       knowledgeable, and under no unusual pressure for a prompt sale, and that
       the transaction would be negotiated in an open and unrestricted market on
       an arm's-length basis, for cash or equivalent consideration, and given an
       adequate amount of time for effective exposure to prospective buyers.
       Market Value assumes that an aircraft's physical condition is average for
       an aircraft of its type and age, and its maintenance time status is at
       mid-life, mid-time (or benefitting from an above-average maintenance
       status if it is new or nearly new). Market Value is synonymous with Fair
       Market Value in that both reflect the state of supply and demand in the
       market that exists at the time.
 
     - ADJUSTED (CURRENT) MARKET VALUE indicates the Market Value of the
       aircraft adjusted for the actual technical status and maintenance
       condition of the aircraft, but still assuming the same market conditions
       and transaction circumstances as described above.
 
     - DISTRESS VALUE is the appraiser's opinion of the price at which an
       aircraft could be sold under abnormal conditions, such as an artificially
       limited marketing time period, the perception of the seller being under
       duress to sell, an auction, a liquidation, commercial restrictions, legal
       complications or other such factors that significantly reduce the
       bargaining leverage of the seller and give the buyer a significant
       advantage that can translate into heavily discounted actual trading
       prices. Apart from the fact that the seller is uncommonly motivated, the
       parties to the transaction are otherwise assumed to be willing, able,
       prudent and knowledgeable, negotiating under the market conditions that
       are perceived to exist at the time, not in an idealized balanced market.
       While Distress Value normally implies that the seller is under some
       duress, there are occasions when buyers, not sellers, are distressed and,
       therefore, willing to pay a premium price.
 
     - FUTURE BASE VALUE is the appraiser's forecast of future aircraft value(s)
       setting forth Base Value(s) as defined above.
 
                                     A-II-21
<PAGE>   116
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
                    APPENDIX A -- AVISTAS VALUE DEFINITIONS
 
     - SECURITIZED VALUE or LEASE-ENCUMBERED VALUE is the appraiser's opinion of
       the value of an aircraft under lease, given a specified lease payment
       stream (rents and term), an estimated future residual value at lease
       termination and an appropriate discount rate. The Securitized Value or
       Lease-Encumbered Value may be more or less than the appraiser's opinion
       of Market Value. The appraiser may not be fully aware of the credit risks
       associated with the parties involved, nor the time-value of money to
       those parties, nor with possible tax consequences pertaining to the
       parties involved, nor with all of the provisions of the lease that may
       pertain to items such as security deposits, purchase options at various
       dates, term extensions, sub-lease rights, repossession rights, reserve
       payments and return conditions.
 
                                     A-II-22
<PAGE>   117
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
                   APPENDIX B -- AVITAS APPRAISAL METHODOLOGY
 
     At AVITAS, we undertake formal periodic value reviews of the approximately
ten dozen aircraft types that we regularly track as well as value updates as
market events and movements require. The primary value opinions we develop are
Market Value, Base Value and Future Base Value. An aircraft's Market Value is
the price at which you could sell the aircraft under the market conditions
prevailing at the time in question and its Base Value is the theoretical value
of the aircraft assuming a balanced market in terms of supply and demand. In
reaching our value opinions, we use data on actual market transactions, various
analytical techniques, a proprietary forecasting model and our own extensive
industry experience. And while Market Value and Base Value embody different
value concepts, we are continually cross checking their relationships to
determine if our value opinions are reasonable given existing market conditions.
 
     Our broad aviation industry backgrounds are critically important; they add
a diversity of viewpoints and a high degree of realism to our value opinions.
Our backgrounds include: aircraft design, performance analysis, traffic and
yield forecasting, fleet forecasting, aircraft finance, the negotiation of
aircraft loans, finance leases and operating leases, problem deal workouts,
repossessions, aircraft sales, jetliner manufacturing, maintenance and overhaul
activities, econometric modeling and forecasting, market research, and database
development.
 
     - MARKET VALUE  In determining Current Market Values, we use a blend of
       techniques and tools. First, through various services and our extensive
       personal contacts, we collect as much actual transaction data as possible
       on aircraft sales, leases, financings and scrappings. Our published
       values assume airframes, engines and landing gear to be halfway through
       their various overhaul and/or life cycles. Because sales of half-life
       aircraft rarely occur, and because sales can include spare engines,
       parts, attached lease streams, tax considerations and other factors,
       judgment and experience are important in adjusting actual transaction
       data to represent clean, half-life Market Values. In addition, because
       over the last several years there have been a large number of aircraft
       leases, our experience and knowledge of the market is used to make value
       inferences from lease rentals and terms.
 
     As a supplement to transaction data, and in some cases in the absence of
actual market activity, we also use other methods to assist in framing Market
Value opinions. We use several analytical tools because we do not believe that
there is any one technique which always results in the "right" number.
Replacement cost analysis can simply be the cost of a new airplane of the same
model or it can be used where it is possible to reproduce an aircraft. It is
often helpful in framing the upper limit of an aircraft's value, particularly
for modified or upgraded aircraft. Examples would be a passenger aircraft such
as the 747-100 which can be converted into freighter configuration or a Stage 2
airplane which can be hushkitted to Stage 3 compliance. Value in use or income
analysis is another technique in which an aircraft's earning capacity over time
is determined and the present value of those earnings is calculated. Because
different operators have different costs, yields and hurdle rates of return,
this technique can yield a range of values. Therefore, the appraiser must use
his judgment to determine what value in that range represents a Market Value
representative of the overall marketplace. Another powerful tool which we use is
should-cost analysis, which is a blend of replacement cost and value in use
analysis. This technique is used when there is little or no market data on a
particular airplane type but there is on similar or competing types. By
 
                                     A-II-23
<PAGE>   118
 
[AVITAS LOGO]
 
- --------------------------------------------------------------------------------
 
                   APPENDIX B -- AVITAS APPRAISAL METHODOLOGY
 
analyzing the economic and operational profiles of competing aircraft, the
appraiser is able to impute what the aircraft in question should cost to
position it competitively.
 
     Once we have formulated our own internal Market Value opinions, we present
them to a small, select group of outside aviation experts -- individuals in the
fields of aircraft manufacturing, sales, remarketing, financing and forecasting
who we know well and regard very highly -- for their review and frank comments.
We consider this "reality check," which often results in further value
refinements, to be a critical part of our value process in that it helps us
combat "ivory tower syndrome."
 
     - BASE VALUE  The determination of Base Value, an aircraft's balanced
       market, long term value, is a highly subjective matter, one in which even
       the most skilled appraisers may have widely divergent views. We use 3
       main tools in developing Base Values. First, we use our own research,
       judgment and perceptions of each aircraft type's long term competitive
       strengths and weaknesses vis-a-vis both competing aircraft types and the
       marketplace as a whole. Second, we utilize a transaction-based computer
       forecasting model developed by a former AVITAS director and refined over
       the years. Based on thousands of actual market transactions, the model
       sets forth a series of value curves which describe the value behaviors of
       aircraft under different circumstances. Third, we do a final reality
       check by comparing our opinion of an aircraft's Base Value to our opinion
       of its Current Market Value and current marketplace conditions.
 
     We analyze each aircraft model to determine its historic, current and
projected competitive position with respect to similar aircraft types in terms
of mission capability (i.e., what are the aircraft's capabilities and to what
extent does the market require those capabilities), economic profile and market
penetration. As a result of weighing those factors, we assign a numerical
"strength" to each aircraft for each year of its economic life, where Strength
10 represents the strongest value performance and Strength 1 the weakest. The
model then takes those strength factors and translates them into the aircraft's
Base and Future Base Values based on its actual replacement cost (or theoretical
replacement cost if it is no longer in production). After Base Values have been
calculated, we compare them to our Current Market Value opinions as a
calibration check of the computer model. In the infrequent case where the
marketplace for that aircraft is in balance, Base Value and Current Market Value
should be the same. In most cases, though, we must subjectively compare Base
Value with Current Market Value to see if we believe the relationship is
reasonable. This may highlight where Base Value inputs require further
refinements. Because of the dynamics of the aircraft marketplace and our
continuing recalibration, Base Value opinions are not static.
 
                                     A-II-24
<PAGE>   119
 
                                                         [AvSolutions Logo]
 
                                                              September 24, 1998
 
Mr. Jacques Lazard
Vice President and Treasurer
America West Airlines
4000 East Sky Harbor Boulevard
Phoenix, Arizona 85034
 
Dear Mr. Lazard:
 
     AvSOLUTIONS is pleased to provide this opinion on the base value, as of
September 1998, of six Airbus Industrie A319 aircraft and two Airbus Industrie
A320 aircraft (the aircraft). The Airbus A319 aircraft are powered by IAE
V2524-A5 engines. The Airbus A320 aircraft are powered by IAE V2527-A5 engines.
The total of eight aircraft will be delivered new to America West Airlines
between the fourth quarter of 1998 and the third quarter of 1999. A listing of
the A319 and A320 aircraft is provided as attachment 1 of this document.
 
     Set forth below is a summary of the methodology, considerations and
assumptions utilized in this appraisal.
 
BASE VALUE
 
     Base value is the appraiser's opinion of the underlying economic value of
an aircraft in an open, unrestricted, stable market environment with a
reasonable balance of supply and demand, and assumes full consideration of its
"highest and best use". An aircraft's base value is founded in the historical
trend of values and in the projection of future value trends and presumes an
arm's length, cash transaction between willing, able and knowledgeable parties,
acting prudently, with an absence of duress and with a reasonable period of time
available for marketing.
 
CURRENT FAIR MARKET VALUE
 
     According to the International Society of Transport Aircraft Trading's
(ISTAT) definition of Fair Market Value (FMV), to which AvSOLUTIONS subscribes,
the quoted FMV is the appraiser's opinion of the most likely trading price that
may be generated for an aircraft under the market circumstances that are
perceived to exist at the time in question. The fair market value assumes that
the aircraft is valued for its highest and best use, that the parties to the
hypothetical sales transaction are willing, able, prudent and knowledgeable, and
under no unusual pressure for a prompt sale, and that the transaction would be
negotiated in an open and unrestricted market on an arm's length basis, for cash
equivalent consideration, and given an adequate amount of time for effective
market exposure to perspective buyers, which AvSOLUTIONS considers to be ten to
twenty months.
 
               7518 - B Diplomat Drive, Manassas, Virginia 20109
                    Telephone 703-330-0461  Fax 703-330-0581
 
                                     A-II-25
<PAGE>   120
 
                                                              [AvSolutions Logo]
- --------------------------------------------------------------------------------
 
Page  2
America West Airlines
 
APPRAISAL METHODOLOGY
 
     The method employed by AvSOLUTIONS to appraise the current and future
values of aircraft and the associated equipment addresses the factors that
influence the market value of an aircraft, such as its age, condition,
configuration, the population of similar aircraft, similar aircraft on the
market, operating costs, cost to acquire a new aircraft, and the state of demand
for transportation services.
 
     To achieve this objective, cross-sectional data concerning the values of
aircraft in each of several general categories is collected and analyzed.
Cross-sectional data is then postulated and compared with reported market values
at a specified point in time. Such data reflects the effect of deterioration in
aircraft performance due to usage and exposure to the elements, as well as the
effect of obsolescence due to the evolutionary development and implementation of
new designs and materials.
 
     The product of the analysis identifies the relationship between the value
of each aircraft and its characteristics, such as age, model designation,
service configuration and engine type. Once the relationship is identified, one
can then postulate the effects of the difference between the economic
circumstances at the time when the cross-sectional data were collected and the
current situation. Therefore, if one can determine the current value of an
aircraft in one category, it is possible to estimate the current values of all
aircraft in that category.
 
     The manufacturer and size of the aircraft usually determine the specific
category to which it is assigned. Segregating the world airplane fleet in this
manner accommodates the potential effects of different size and different design
philosophies.
 
     The variability of the data used by AvSOLUTIONS to determine the current
and future market values implies that the actual value realized will fall within
a range of values. Therefore, if a contemplated value falls within the specified
confidence range, AvSOLUTIONS cannot reject the hypothesis that it is a
reasonable representation of the current market situation.
 
LIMITING CONDITIONS AND ASSUMPTIONS
 
     In order to conduct this valuation, AvSOLUTIONS is solely relying on
information as supplied by America West Airlines or Morgan Stanley, and from
data within AvSOLUTIONS' own database. In determining the base value of the
subject Airbus A319 and Airbus A320 aircraft, the following assumptions have
been researched and determined:
 
1. AvSOLUTIONS has not inspected these aircraft or their maintenance records;
accordingly, AvSOLUTIONS cannot attest to their specific location or condition.
 
2. The aircraft will be delivered new to America West Airlines between the
fourth quarter of 1998 and the third quarter of 1999.
 
3. The aircraft will be certified, maintained and operated under United States
Federal Aviation Regulation (FAR) part 121.
 
4. All mandatory inspections and Airworthiness Directives have been complied
with.
 
5. The aircraft have no damage history.
 
6. The aircraft are in good condition.
 
                                     A-II-26
<PAGE>   121
 
                                                              [AvSolutions Logo]
- --------------------------------------------------------------------------------
 
Page  3
America West Airlines
 
7. AvSOLUTIONS considers the economic useful life of these aircraft to be at
least 32 years.
 
     Based upon the above methodology, considerations and assumptions, it is
AvSOLUTIONS' opinion that the base values of each aircraft are as listed in
attachment 1.
 
                                     A-II-27
<PAGE>   122
 
                                                              [AvSolutions Logo]
- --------------------------------------------------------------------------------
 
Page  4
America West Airlines
 
STATEMENT OF INDEPENDENCE
 
     This appraisal report represents the opinion of AvSOLUTIONS, and is
intended to be advisory in nature. Therefore, AvSOLUTIONS assumes no
responsibility or legal liability for actions taken or not taken by the Client
or any other party with regard to the subject aircraft. By accepting this
report, the Client agrees that AvSOLUTIONS shall bear no responsibility or legal
liability regarding this report. Further, this report is prepared for the
exclusive use of the Client and shall not be provided to other parties without
the Client's express consent.
 
     Aviation Solutions Inc. (AvSOLUTIONS) hereby states that this valuation
report has been independently prepared and fairly represents the subject
aircraft and AvSOLUTIONS' opinion of their values. Aviation Solutions Inc.
(AvSOLUTIONS) further states that it has no present or contemplated future
interest or association with the subject aircraft.
 
Signed,
 
/s/ Bryant Lynch
- -----------------------------------
Bryant Lynch
Manager, Commercial Appraisals
 
                                     A-II-28
<PAGE>   123
 
                                                              [AvSolutions Logo]
- --------------------------------------------------------------------------------
 
                                  ATTACHMENT 1
 
                            EETC COLLATERAL SUMMARY
 
<TABLE>
<CAPTION>
    AIRCRAFT                    DELIVERY
      NO.         AIRCRAFT        DATE        ENGINES    MGTOW         BASE VALUE
                                                                      (MILLIONS OF
                                                                        DOLLARS)
  <C>            <S>          <C>             <C>       <C>       <C>
       1         Airbus A319   Oct 1998       V2524-A5                    38.14
                                                        166,447
       2         Airbus A319   Dec 1998       V2524-A5                    38.14
                                                        166,447
       3         Airbus A319   Dec 1998       V2524-A5                    38.14
                                                        166,447
       4         Airbus A319   Jul 1999       V2524-A5                    39.28
                                                        166,447
       5         Airbus A319   Jul 1999       V2524-A5                    39.28
                                                        166,447
       6         Airbus A319   Aug 1999       V2524-A5                    39.28
                                                        166,447
 
  AIRCRAFT NO.    AIRCRAFT    DELIVERY DATE   ENGINES    MGTOW         BASE VALUE
                                                                  (MILLIONS OF DOLLARS)
       7         Airbus A320   Feb 1999       V2527-A5                    44.39
                                                        169,754
       8         Airbus A320   May 1999       V2527-A5                    44.72
                                                        169,754
</TABLE>
 
                                     A-II-29
<PAGE>   124
 
                           [BK ASSOCIATES, INC. LOGO]
 
                            1295 Northern Boulevard
                           Manhasset, New York 11030
                      (516) 365-6272 - Fax (516) 365-6287
 
                                          September 24, 1998
 
Mr. Jacques Lazard
Vice President & Treasurer
AMERICA WEST AIRLINES
4000 E. Sky Harbor Boulevard
Phoenix, AZ 85034
 
Dear Mr. Lazard:
 
In response to your request, BK Associates, Inc. is pleased to provide this
opinion on the current Base Value as of the respective delivery date on each of
six Airbus Industrie A319-132 aircraft, powered by International Aero Engines
V2524-A5 engines and two A320-232 aircraft, powered by International Aero
Engines V2527-A5 engines (Aircraft). The Aircraft, scheduled to be delivered to
America West Airlines between October 1998 and August 1999, are further
identified in the conclusions of this letter by scheduled delivery date, engine
type and maximum takeoff weight.
 
Set forth below is a summary of the methodology, considerations and assumptions
utilized in this appraisal.
 
CURRENT FAIR MARKET VALUE
 
According to the International Society of Transport Aircraft Trading's (ISTAT)
definition of FMV, to which BK Associates subscribes, the quoted FMV is the
Appraiser's opinion of the most likely trading price that may be generated for
an aircraft under the market circumstances that are perceived to exist at the
time in question. The FMV assumes that the aircraft is valued for its highest
and best use, that the parties to the hypothetical sale transaction are willing,
able, prudent and knowledgeable, and under no unusual pressure for a prompt
sale, and that the transaction would be negotiated in an open and unrestricted
market on an arm's length basis, for cash or equivalent consideration, and given
an adequate amount of time for effective exposure to prospective buyers, which
BK Associates considers to be 12 to 18 months.
 
BASE VALUE
 
Base value is the Appraiser's opinion of the underlying economic value of an
aircraft in an open, unrestricted, stable market environment with a reasonable
balance of supply and demand, and assumes full consideration of its "highest and
best use". An aircraft's base value is founded in the historical trend of values
and in the projection of future value trends and presumes an arm's length, cash
transaction between willing, able and knowledgeable parties, acting prudently,
with an absence of duress and with a reasonable period of time available for
marketing.
 
VALUE METHODOLOGY
 
Fair market valuations are determined based upon one of three methods:
comparable recent sales, replacement cost or rate of return to investor. In this
appraisal, BK used the comparable sales method, which is the most common method,
in determining the base values of the Aircraft. This method uses industry data
to ascertain the prices realized in recent sales of comparable models. The fair
market value of the base Aircraft is based on BK's familiarity with the aircraft
type, its earnings potential in commercial service, its knowledge of its
capabilities and the uses to which it will be put worldwide, its knowledge of
 
                                     A-II-30
<PAGE>   125
 
                                                      [BK ASSOCIATES, INC. LOGO]
Mr. Jacques Lazard
September 24, 1998
Page  2
 
the marketing of used aircraft, and the factors affecting the fair market value
of such aircraft, and on its knowledge of the asking, offered and transaction
prices for similar competitive, and alternative equipment, as well as
transactions and negotiations involving basically identical aircraft. These
realizations, however, which reflect the market supply and demand at the time of
sale, are subject to minor adjustments for other conditions existing at the time
of the appraisal.
 
LIMITING CONDITIONS AND ASSUMPTIONS
 
BK has neither inspected the Aircraft nor their maintenance records but relied
upon information supplied by you and from BK's own database. In determining the
base value of an aircraft, the following assumptions apply to the aircraft:
 
1.  Unless it is new, the aircraft has half-time remaining to its next major
    overhauls or scheduled shop visit on its airframe, engines, landing gear and
    auxiliary power unit.
 
2.  The aircraft is in compliance under a Federal Aviation Administration
    approved airline maintenance program, with all airworthiness directives,
    mandatory modifications and applicable service bulletins currently up to
    industry standard.
 
3.  The interior of the aircraft is in a standard configuration for its specific
    type, with the buyer furnished equipment and options of the types and models
    generally accepted and utilized in the industry.
 
4.  The aircraft is in current flight operations.
 
5.  The aircraft is sold for cash without seller financing.
 
6.  The Aircraft is in average or better condition.
 
7.  There is no accident damage.
 
CONCLUSIONS
 
Based on the above methodology, considerations and assumptions, and since the
Aircraft are all new and not yet in service, it is our opinion that the current
base value of each aircraft as of its scheduled delivery date is as follows:
 
<TABLE>
<CAPTION>
                     Maximum   Scheduled    Current
Aircraft  Aircraft   Takeoff   Delivery    Base Value
 Number    Model     Weight      Date        ($Mil)
- --------  --------   -------   ---------   ----------
<S>       <C>        <C>       <C>         <C>
       1    A319     166,447     10/98       33.00
       2    A319     166,447     12/98       33.10
       3    A319     166,447     12/98       33.10
       4    A319     166,447     07/99       33.50
       5    A319     166,447     07/99       33.50
       6    A319     166,447     08/99       33.60
       7    A320     169,754     02/99       39.70
       8    A320     169,754     05/99       39.80
</TABLE>
 
                                     A-II-31
<PAGE>   126
 
                                                      [BK ASSOCIATES, INC. LOGO]
Mr. Jacques Lazard
September 24, 1998
Page  3
 
BK Associates, Inc. has no present or contemplated future interest in the
Aircraft, nor any interest that would preclude our making a fair and unbiased
estimate. This appraisal represents the opinion of BK Associates, Inc. and
reflects our best judgment based on the information available to us at the time
of preparation and the time and budget constraints imposed by the client. It is
not given as a recommendation, or as an inducement, for any financial
transaction and further, BK Associates, Inc. assumes no responsibility or legal
liability for any action taken or not taken by the addressee, or any other
party, with regard to the appraised equipment. By accepting this appraisal, the
addressee agrees that BK Associates, Inc. shall bear no such responsibility or
legal liability. This appraisal is prepared for the use of the addressee and
shall not be provided to other parties without the express consent of the
addressee.
 
                                          Sincerely yours,
 
                                          BK ASSOCIATES, INC.
 
                                          /s/ R. L. Britton
          ----------------------------------------------------------------------
                                          R. L. Britton
                                          Vice President
                                          ISTAT Certified Appraiser
 
RLB/kf
 
                                     A-II-32
<PAGE>   127
 
                                    PART II
 
                     INFORMATION NOT REQUIRED IN PROSPECTUS
 
ITEM 20.  INDEMNIFICATION OF OFFICERS AND DIRECTORS
 
     The Company's Restated Certificate of Incorporation and Restated Bylaws
provide that the Company will indemnify each of its directors and officers to
the full extent permitted by the laws of the State of Delaware and may indemnify
certain other persons as authorized by the Delaware General Corporation Law (the
"GCL").
 
     Section 145 of the GCL provides as follows:
 
     "(a) A corporation shall have power to indemnify any person who was or is a
party or is threatened to be made a party to any threatened, pending or
completed action, suit or proceeding, whether civil, criminal, administrative or
investigative (other than an action by or in the right of the corporation) by
reason of the fact that he is or was a director, officer, employee or agent of
the corporation, or is or was serving at the request of the corporation as a
director, officer, employee or agent of another corporation, partnership, joint
venture, trust or other enterprise, against expenses (including attorneys'
fees), judgments, fines and amounts paid in settlement actually and reasonably
incurred by him in connection with such action, suit or proceeding if he acted
in good faith and in a manner he reasonably believed to be in or not opposed to
the best interests of the corporation, and, with respect to any criminal action
or proceeding, had no reasonable cause to believe his conduct was unlawful. The
termination of any action, suit or proceeding by judgment, order, settlement,
conviction, or upon a plea of nolo contendere or its equivalent, shall not, of
itself, create a presumption that the person did not act in good faith and in a
manner which he reasonably believed to be in or not opposed to the best
interests of the corporation, and, with respect to any criminal action or
proceeding, had reasonable cause to believe that his conduct was unlawful.
 
     (b) A corporation shall have power to indemnify any person who was or is a
party or is threatened to be made a party to any threatened, pending or
completed action or suit by or in the right of the corporation to procure a
judgment in its favor by reason of the fact that he is or was a director,
officer, employee or agent of the corporation, or is or was serving at the
request of the corporation as a director, officer, employee or agent of another
corporation, partnership, joint venture, trust or other enterprise against
expenses (including attorneys' fees) actually and reasonably incurred by him in
connection with the defense or settlement of such action or suit if he acted in
good faith and in a manner he reasonably believed to be in or not opposed to the
best interests of the corporation and except that no indemnification shall be
made in respect of any claim, issue or matter as to which such person shall have
been adjudged to be liable to the corporation unless and only to the extent that
the Court of Chancery or the court in which such action or suit was brought
shall determine upon application that, despite the adjudication of liability but
in view of all the circumstances of the case, such person is fairly and
reasonably entitled to indemnity for such expenses which the Court of Chancery
or such other court shall deem proper.
 
     (c) To the extent that a director, officer, employee or agent of a
corporation has been successful on the merits or otherwise in defense of any
action, suit or proceeding referred to in subsections (a) and (b) of this
section, or in defense of any claim, issue or matter therein, he shall be
indemnified against expenses (including attorneys' fees) actually and reasonably
incurred by him in connection therewith.
 
     (d) Any indemnification under subsections (a) and (b) of this section
(unless ordered by a court) shall be made by the corporation only as authorized
in the specific case upon a determination that indemnification of the director,
officer, employee or agent is proper in the circumstances because he has met the
applicable standard of conduct set forth in subsections (a) and (b). Such
determination shall be made (1) by a majority vote of the board of directors who
are not parties to such action, suit or proceeding, even though less than a
quorum, or (2) if there are no such directors, or if such directors so direct,
by independent legal counsel in a written opinion, or (3) by the stockholders.
 
     (e) Expenses (including attorneys' fees) incurred by an officer or director
in defending any civil, criminal, administrative, or investigative action, suit
or proceeding may be paid by the corporation in
                                      II-1
<PAGE>   128
 
advance of the final disposition of such action, suit or proceeding upon receipt
of undertaking by or on behalf of such director or officer to repay such amount
if it shall ultimately be determined that he is not entitled to be indemnified
by the corporation as authorized in this section. Such expenses (including
attorneys' fees) incurred by other employees and agents may be so paid upon such
terms and conditions, if any, as the board of directors deems appropriate.
 
     (f) The indemnification and advancement of expenses provided by, or granted
pursuant to, the other subsections of this section shall not be deemed exclusive
of any other rights to which those seeking indemnification or advancement of
expenses may be entitled under any bylaw, agreement, vote of stockholders or
disinterested directors or otherwise, both as to action in his official capacity
and as to action in another capacity while holding such office.
 
     (g) A corporation shall have power to purchase and maintain insurance on
behalf of any person who is or was a director, officer, employee or agent of the
corporation, or is or was serving at the request of the corporation as a
director, officer, employee or agent of another corporation, partnership, joint
venture, trust or other enterprise against any liability asserted against him
and incurred by him in any such capacity, or arising out of his status as such,
whether or not the corporation would have the power to indemnify him against
such liability under this section.
 
     (h) For purposes of this section, references to "the corporation" shall
include, in addition to the resulting corporation, any constituent corporation
(including any constituent of a constituent) absorbed in a consolidation or
merger which, if its separate existence had continued, would have had power and
authority to indemnify its directors, officers, and employees or agents, so that
any person who is or was a director, officer, employee or agent for such
constituent corporation, or is or was serving at the request of such constituent
corporation as a director, officer, employee or agent of another corporation,
partnership, joint venture, trust or other enterprise, shall stand in the same
position under this section with respect to the resulting or surviving
corporation as he would have with respect to such constituent corporation if its
separate existence had continued.
 
     (i) For purposes of this section, references to "other enterprises" shall
include employee benefit plans; references to "fines" shall include any excise
taxes assessed on a person with respect to an employee benefit plan; and
references to "serving at the request of the corporation" shall include any
service as a director, officer, employee or agent of the corporation which
imposes duties on, or involves services by, such director, officer, employee, or
agent with respect to an employee benefit plan, its participants, or
beneficiaries; and a person who acted in good faith and in a manner he
reasonably believed to be in the interest of the participants and beneficiaries
of an employee benefit plan shall be deemed to have acted in a manner "not
opposed to the best interests of the corporation" as referred to in this
section.
 
     (j) The indemnification and advancement of expenses provided by, or granted
pursuant to, this section shall, unless otherwise provided when authorized or
ratified, continue as to a person who has ceased to be a director, officer,
employee or agent and shall inure to the benefit of the heirs, executors and
administrators of such a person.
 
     (k) The Court of Chancery is hereby vested with exclusive jurisdiction to
hear and determine all actions for advancement of expenses or indemnification
brought under this section or under any bylaw, agreement, vote of stockholders
or disinterested directors, or otherwise. The Court of Chancery may summarily
determine a corporation's obligation to advance expenses (including attorneys'
fees)."
 
     The Restated Certificate of Incorporation and Restated Bylaws also limit
the personal liability of directors to the Company and its stockholders for
monetary damages resulting from certain breaches of the directors' fiduciary
duties. The Restated Certificate of Incorporation of the Company provides as
follows:
 
     "A person who is or was a Director of the Corporation shall not be
personally liable to the Corporation or its stockholders for monetary damages
for breach of fiduciary duty as a Director, except for liability (i) for any
breach of the Director's duty of loyalty to the corporation or its stockholders,
(ii) for acts or omissions not in good faith or which involve intentional
misconduct or a knowing violation of law, (iii) under Section 174 of the DGCL or
(iv) for any transaction from which the Director derived any
                                      II-2
<PAGE>   129
 
improper personal benefit. If the DGCL is amended to authorize corporate action
further eliminating or limiting the personal liability of Directors, then the
liability of Directors of the Corporation shall be eliminated or limited to the
full extent permitted by the DGCL, as so amended. The elimination and limitation
of liability provided herein shall continue after a Director has ceased to
occupy such position as to acts or omissions occurring during such Director's
term or terms of office, and no amendment or repeal of this Section 12 shall
apply to or have any effect on the liability or alleged liability of any
Director of the Corporation for or with respect to any acts or omissions of such
Director occurring prior to such amendment or repeal."
 
     The Company maintains directors' and officers' liability insurance.
 
ITEM 21.  EXHIBITS AND FINANCIAL STATEMENT SCHEDULES
 
<TABLE>
<CAPTION>
EXHIBIT                           DESCRIPTION
- -------                           -----------
<S>       <C>
 4.1      Form of 6.87% America West Airlines Pass Through Certificate
          Series 1998-1A-O (included in Exhibit 4.4)
 4.2      Form of 7.12% America West Airlines Pass Through Certificate
          Series 1998-1B-O (included in Exhibit 4.6)
 4.3      Form of 7.84% America West Airlines Pass Through Certificate
          Series 1998-1C-O (included in Exhibit 4.8)
 4.4      Pass Through Trust Agreement, dated as of October 6, 1998,
          between America West Airlines, Inc., and Wilmington Trust
          Company, as Trustee, made with respect to the formation of
          America West Airlines Pass Through Trust, Series 1998-1A-0
          and the issuance of 6.87% Initial Pass Through Certificates,
          Series 1998-1A-O and 6.87% Exchange Pass Through
          Certificates, Series 1998-1A-O
 4.5      Pass Through Trust Agreement, dated as of October 6, 1998,
          between America West Airlines, Inc., and Wilmington Trust
          Company, as Trustee, made with respect to the formation of
          America West Airlines Pass Through Trust, Series 1998-1A-S
          and the issuance of 6.87% Initial Pass Through Certificates,
          Series 1998-1A-S and 6.87% Exchange Pass Through
          Certificates, Series 1998-1A-S
 4.6      Pass Through Trust Agreement, dated as of October 6, 1998,
          between America West Airlines, Inc., and Wilmington Trust
          Company, as Trustee, made with respect to the formation of
          America West Airlines Pass Through Trust, Series 1998-1B-0
          and the issuance of 7.12% Initial Pass Through Certificates,
          Series 1998-1B-O and 7.12% Exchange Pass Through
          Certificates, Series 1998-1B-O
 4.7      Pass Through Trust Agreement, dated as of October 6, 1998,
          between America West Airlines, Inc., and Wilmington Trust
          Company, as Trustee, made with respect to the formation of
          America West Airlines Pass Through Trust, Series 1998-1B-S
          and the issuance of 7.12% Initial Pass Through Certificates,
          Series 1998-1B-S and 7.12% Exchange Pass Through
          Certificates, Series 1998-1B-S
 4.8      Pass Through Trust Agreement, dated as of October 6, 1998,
          between America West Airlines, Inc., and Wilmington Trust
          Company, as Trustee, made with respect to the formation of
          America West Airlines Pass Through Trust, Series 1998-1C-O
          and the issuance of 7.84% Initial Pass Through Certificates,
          Series 1998-1C-O and 7.84% Exchange Pass Through
          Certificates, Series 1998-1C-O
 4.9      Pass Through Trust Agreement, dated as of October 6, 1998,
          between America West Airlines, Inc., and Wilmington Trust
          Company, as Trustee, made with respect to the formation of
          America West Airlines Pass Through Trust, Series 1998-1C-S
          and the issuance of 7.84% Initial Pass Through Certificates,
          Series 1998-1C-S and 7.84% Exchange Pass Through
          Certificates, Series 1998-1C-S
</TABLE>
 
                                      II-3
<PAGE>   130
 
<TABLE>
<CAPTION>
EXHIBIT                           DESCRIPTION
- -------                           -----------
<S>       <C>
 4.10     Revolving Credit Agreement, dated October 6, 1998, between
          Wilmington Trust Company, as Subordination Agent, as agent
          and trustee for the America West Airlines Pass Through Trust
          1998-1A, as Borrower; and ABN AMRO Bank N.V., Chicago
          Branch, as Liquidity Provider
 4.11     Revolving Credit Agreement, dated October 6, 1998, between
          Wilmington Trust Company, as Subordination Agent, as agent
          and trustee for the America West Airlines Pass Through Trust
          1998-1B, as Borrower; and ABN AMRO Bank N.V., Chicago
          Branch, as Liquidity Provider
 4.12     Revolving Credit Agreement, dated October 6, 1998, between
          Wilmington Trust Company, as Subordination Agent, as agent
          and trustee for the America West Airlines Pass Through Trust
          1998-1C, as Borrower; and ABN AMRO Bank N.V., Chicago
          Branch, as Liquidity Provider
 4.13     Intercreditor Agreement, dated as of October 6, 1998, among
          Wilmington Trust Company, as Trustee under the America West
          Airlines Pass Through Trust 1998-1A, America West Airlines
          Pass Through Trust 1998-1B and America West Airlines Pass
          Through Trust 1998-1C and ABN AMRO Bank N.V., Chicago
          Branch, as Class A Liquidity Provider, Class B Liquidity
          Provider and Class C Liquidity Provider, and Wilmington
          Trust Company, as Subordination Agent and Trustee
 4.14     Exchange and Registration Rights Agreement, dated as of
          October 6, 1998, among America West Airlines, Inc.;
          Wilmington Trust Company, as Trustee under America West
          Airlines Pass Through Trust, Series 1998-1A-O, America West
          Airlines Pass Through Trust, Series 1998-1B-O and America
          West Airlines Pass Through Trust, Series 1998-1C-O; and
          Morgan Stanley & Co. Incorporated, Donaldson, Lufkin &
          Jenrette Securities Corporation, Merrill Lynch, Pierce,
          Fenner & Smith Incorporated and Salomon Smith Barney Inc.
 4.15     Deposit Agreement (Class A), dated as of October 6, 1998,
          between Wilmington Trust Company, as Escrow Agent under the
          Escrow and Paying Agent Agreement, and ABN AMRO Bank N.V.,
          Chicago Branch, as Depositary
 4.16     Deposit Agreement (Class B), dated as of October 6, 1998,
          between Wilmington Trust Company, as Escrow Agent under the
          Escrow and Paying Agent Agreement, and ABN AMRO Bank N.V.,
          Chicago Branch, as Depositary
 4.17     Deposit Agreement (Class C), dated as of October 6, 1998,
          between Wilmington Trust Company as Escrow Agent under the
          Escrow and Paying Agent Agreement, and ABN AMRO Bank N.V.,
          Chicago Branch, as Depositary
 4.18     Escrow and Paying Agent Agreement (Class A), dated as of
          October 6, 1998, among Wilmington Trust Company, as Escrow
          Agent; Morgan Stanley & Co. Incorporated, Donaldson, Lufkin
          & Jenrette Securities Corporation, Merrill Lynch, Pierce,
          Fenner & Smith Incorporated and Salomon Smith Barney Inc.,
          as Initial Purchasers; Wilmington Trust Company, as Pass
          Through Trustee for and on behalf of America West Airlines
          Pass Through Trust 1998-1A-0; and Wilmington Trust Company
          as Paying Agent
 4.19     Escrow and Paying Agent Agreement (Class B), dated as of
          October 6, 1998, among Wilmington Trust Company, as Escrow
          Agent; Morgan Stanley & Co. Incorporated, Donaldson, Lufkin
          & Jenrette Securities Corporation, Merrill Lynch, Pierce,
          Fenner & Smith Incorporated and Salomon Smith Barney Inc.,
          as Initial Purchasers; Wilmington Trust Company, as Pass
          Through Trustee for and on behalf of America West Airlines
          Pass Through Trust 1998-1B-0; and Wilmington Trust Company
          as Paying Agent
 4.20     Escrow and Paying Agent Agreement (Class C), dated as of
          October 6, 1998, among Wilmington Trust Company, as Escrow
          Agent; Morgan Stanley & Co. Incorporated, Donaldson, Lufkin
          & Jenrette Securities Corporation, Merrill Lynch, Pierce,
          Fenner & Smith Incorporated and Salomon Smith Barney Inc.,
          as Initial Purchasers; Wilmington Trust Company, as Pass
          Through Trustee for and on behalf of America West Airlines
          Pass Through Trust 1998-1C-0; and Wilmington Trust Company
          as Paying Agent
</TABLE>
 
                                      II-4
<PAGE>   131
 
<TABLE>
<CAPTION>
EXHIBIT                           DESCRIPTION
- -------                           -----------
<S>       <C>
 4.21     Note Purchase Agreement dated as of October 6, 1998, among
          America West Airlines, Inc., Wilmington Trust Company as
          Pass Through Trustee under each of the Pass Through Trust
          Agreements, and Wilmington Trust Company, as Subordination
          Agent, Escrow Agent and Paying Agent
 5.1      Opinion of Morris, James, Hitchens & Williams as to the
          legality of the New Certificates being registered hereby
12.1      Computation of ratio of earnings to fixed charges
23.1      Consent of Morris, James, Hitchens & Williams (included in
          Exhibit 5.1)
23.2      Consent of KPMG Peat Marwick LLP
23.3      Consent of AVITAS, Inc.
23.4      Consent of AvSolutions
23.5      Consent of BK Associates, Inc.
24.1      Power of Attorney (see signature page in Part II of
          Registration Statement)
25.1      Statement of Eligibility of Wilmington Trust Company for the
          1998-1A Pass Through Certificates, on Form T-1
25.2      Statement of Eligibility of Wilmington Trust Company for the
          1998-1B Pass Through Certificates, on Form T-1
25.3      Statement of Eligibility of Wilmington Trust Company for the
          1998-1C Pass Through Certificates, on Form T-1
99.1      Form of Letter of Transmittal
99.2      Form of Notice of Guaranteed Delivery
99.3      Form of Letter to Brokers, Dealers, Commercial Banks, Trust
          Companies and Other Nominees
99.4      Form of Letter to Clients
</TABLE>
 
ITEM 22.  UNDERTAKINGS
 
     The undersigned Registrant hereby undertakes:
 
     (1) To file, during any period in which offers or sales are being made, a
post-effective amendment to this registration statement:
 
          (i)  To include any prospectus required by Section 10(a)(3) of the
     Securities Act of 1933;
 
          (ii) To reflect in the prospectus any facts or events arising after
     the effective date of the registration (or the most recent post-effective
     amendment thereof) which, individually or in the aggregate, represent a
     fundamental change in the information set forth in the registration
     statement. Notwithstanding the foregoing, any increase or decrease in
     volume of securities offered (if the total dollar value of securities
     offered would not exceed that which was registered) and any deviation from
     the low or high and of the estimated maximum offering range may be
     reflected in the form of prospectus filed with the SEC pursuant to Rule
     424(b) if, in the aggregate, the changes in volume and price represent no
     more than 20 percent change in the maximum aggregate offering price set
     forth in the "Calculation of Registration Fee" table in the effective
     registration statement;
 
          (iii) To include any material information with respect to the plan of
     distribution not previously disclosed in the registration statement or any
     material change to such information in the registration statement;
     provided, however, that paragraphs (a)(1)(i) and (a)(1)(ii) shall not apply
     if the information required to be included in a post-effective amendment by
     those paragraphs is contained in periodic reports filed by the registrant
     pursuant to section 13 or section 15(d) of the Securities Exchange Act of
     1934 that are incorporated by reference in the registration statement.
 
                                      II-5
<PAGE>   132
 
     (2) That, for the purpose of determining any liability under the Securities
Act, each such post-effective amendment shall be deemed to be a new registration
statement relating to the securities offered therein, and the offering of such
securities at that time shall be deemed to be the initial bona fide offering
thereof.
 
     (3) To remove from registration by means of a post-effective amendment any
of the securities being registered which remain unsold at the termination of the
offering.
 
     The undersigned registrant hereby undertakes that, for purposes of
determining any liability under the Securities Act of 1933, each filing of the
registrant's annual report pursuant to Section 13(a) or 15(d) of the Securities
Exchange Act of 1934 (and, where applicable, each filing of an employee benefit
plans annual report pursuant to Section 15(d) of the Securities Exchange Act of
1934) that is incorporated by reference in the registration statement shall be
deemed to be a new registration statement relating to the securities offered
therein, and the offering of such securities at that time shall be deemed to be
the initial bona fide offering thereof.
 
     Insofar as indemnification for liabilities arising under the Securities Act
of 1933 may be permitted to directors, officers and controlling persons of the
registrant, pursuant to the foregoing provisions, or otherwise, the registrant
has been advised that in the opinion of the Securities and Exchange Commission
such indemnification is against public policy as expressed in the Securities Act
of 1933 and is, therefore, unenforceable. In the event that a claim for
indemnification against such liabilities (other than the payment by the
registrant of expenses incurred or paid by a director, officer or controlling
person of the registrant in the successful defense of any action, suit or
proceeding) is asserted by any such director, officer or controlling person in
connection with the securities being registered, the registrant will, unless in
the opinion of its counsel the matter has been settled by controlling precedent,
submit to a court of appropriate jurisdiction the question of whether or not
such indemnification is against public policy as expressed in the Securities Act
of 1933 and will be governed by the final adjudication of such issue.
 
     The undersigned registrant hereby undertakes to respond to requests for
information that is incorporated by reference into the prospectus pursuant to
Item 4, 10(b), 11, or 13 of this form, within one business day of receipt of
such request, and to send the incorporated documents by first class mail or
other equally prompt means. This includes information contained in documents
filed subsequent to the effective date of the registration statement through the
date of responding to the request.
 
     The undersigned registrant hereby undertakes to supply by means of a
post-effective amendment all information concerning a transaction, and the
company being acquired involved therein, that was not the subject of and
included in the registration statement when it became effective.
 
                                      II-6
<PAGE>   133
 
                                   SIGNATURES
 
     Pursuant to the requirements of the Securities Act of 1933, as amended, the
registrant has duly caused this Registration Statement to be signed on its
behalf by the undersigned, thereunto duly authorized, in the City of Tempe,
State of Arizona, on the 16th day of December, 1998.
 
                                          America West Airlines, Inc.
 
                                          By: /s/ W. DOUGLAS PARKER
                                            ------------------------------------
                                              W. Douglas Parker
                                              Senior Vice President and Chief
                                              Financial Officer
 
                               POWER OF ATTORNEY
 
     KNOW ALL PERSONS BY THESE PRESENTS, that each person whose signature
appears below hereby constitutes and appoints, jointly and severally, William A.
Franke, W. Douglas Parker, Stephen L. Johnson, and each of them acting
individually, as his attorney-in-fact, each with full power of substitution, for
him in any and all capacities, including as an individual or as an officer or
director authorized to act on behalf of an entity, to sign any and all
amendments to this Registration Statement, and to file the same, with exhibits
thereto and other documents in connection therewith, with the Securities and
Exchange Commission, hereby ratifying and confirming our signatures as they may
be signed by our said attorney to any and all amendments to said Registration
Statement.
 
     Pursuant to the requirements of the Securities Act of 1933, as amended,
this Registration Statement has been signed by the following persons in the
capacities and on the dates indicated:
 
<TABLE>
<CAPTION>
                SIGNATURE                                   TITLE                         DATE
                ---------                                   -----                         ----
<S>                                         <C>                                     <C>
 
/s/ WILLIAM A. FRANKE                       Chairman of the Board of                December 16, 1998
- ------------------------------------------  Directors and Director
William A. Franke
 
/s/ RICHARD R. GOODMANSON                   President, Chief Executive Officer and  December 16, 1998
- ------------------------------------------  Director (Principal Executive Officer)
Richard R. Goodmanson
 
/s/ W. DOUGLAS PARKER                       Senior Vice President and Chief         December 16, 1998
- ------------------------------------------  Financial Officer (Principal Financial
W. Douglas Parker                           Officer)
 
/s/ MICHAEL R. CARREON                      Vice President and Controller           December 16, 1998
- ------------------------------------------  (Principal Accounting Officer)
Michael R. Carreon
 
/s/ FREDERICK W. BRADLEY                    Director                                December 16, 1998
- ------------------------------------------
Frederick W. Bradley
 
                                            Director
- ------------------------------------------
James G. Coulter
 
/s/ JOHN L. GOOLSBY                         Director                                December 16, 1998
- ------------------------------------------
John L. Goolsby
 
</TABLE>
 
                                      II-7
<PAGE>   134
 
<TABLE>
<CAPTION>
                SIGNATURE                                   TITLE                         DATE
                ---------                                   -----                         ----
<S>                                         <C>                                     <C>
           /s/ WALTER T. KLENZ              Director                                December 16, 1998
- ------------------------------------------
             Walter T. Klenz
 
          /s/ RICHARD C. KRAEMER            Director                                December 16, 1998
- ------------------------------------------
            Richard C. Kraemer
 
          /s/ DENISE M. O'LEARY             Director                                December 16, 1998
- ------------------------------------------
            Denise M. O'Leary
 
         /s/ RICHARD P. SCHIFTER            Director                                December 16, 1998
- ------------------------------------------
           Richard P. Schifter
 
           /s/ JOHN F. TIERNEY              Director                                December 16, 1998
- ------------------------------------------
             John F. Tierney
</TABLE>
 
                                      II-8
<PAGE>   135
 
                                 EXHIBIT INDEX
 
<TABLE>
<CAPTION>
EXHIBIT                           DESCRIPTION
- -------                           -----------
<C>       <S>
  4.1     Form of 6.87% America West Airlines Pass Through Certificate
          Series 1998-1A-O (included in Exhibit 4.4)
  4.2     Form of 7.12% America West Airlines Pass Through Certificate
          Series 1998-1B-O (included in Exhibit 4.6)
  4.3     Form of 7.84% America West Airlines Pass Through Certificate
          Series 1998-1C-O (included in Exhibit 4.8)
  4.4     Pass Through Trust Agreement, dated as of October 6, 1998,
          between America West Airlines, Inc., and Wilmington Trust
          Company, as Trustee, made with respect to the formation of
          America West Airlines Pass Through Trust, Series 1998-1A-0
          and the issuance of 6.87% Initial Pass Through Certificates,
          Series 1998-1A-O and 6.87% Exchange Pass Through
          Certificates, Series 1998-1A-O
  4.5     Pass Through Trust Agreement, dated as of October 6, 1998,
          between America West Airlines, Inc., and Wilmington Trust
          Company, as Trustee, made with respect to the formation of
          America West Airlines Pass Through Trust, Series 1998-1A-S
          and the issuance of 6.87% Initial Pass Through Certificates,
          Series 1998-1A-S and 6.87% Exchange Pass Through
          Certificates, Series 1998-1A-S
  4.6     Pass Through Trust Agreement, dated as of October 6, 1998,
          between America West Airlines, Inc., and Wilmington Trust
          Company, as Trustee, made with respect to the formation of
          America West Airlines Pass Through Trust, Series 1998-1B-0
          and the issuance of 7.12% Initial Pass Through Certificates,
          Series 1998-1B-O and 7.12% Exchange Pass Through
          Certificates, Series 1998-1B-O
  4.7     Pass Through Trust Agreement, dated as of October 6, 1998,
          between America West Airlines, Inc., and Wilmington Trust
          Company, as Trustee, made with respect to the formation of
          America West Airlines Pass Through Trust, Series 1998-1B-S
          and the issuance of 7.12% Initial Pass Through Certificates,
          Series 1998-1B-S and 7.12% Exchange Pass Through
          Certificates, Series 1998-1B-S
  4.8     Pass Through Trust Agreement, dated as of October 6, 1998,
          between America West Airlines, Inc., and Wilmington Trust
          Company, as Trustee, made with respect to the formation of
          America West Airlines Pass Through Trust, Series 1998-1C-O
          and the issuance of 7.84% Initial Pass Through Certificates,
          Series 1998-1C-O and 7.84% Exchange Pass Through
          Certificates, Series 1998-1C-O
  4.9     Pass Through Trust Agreement, dated as of October 6, 1998,
          between America West Airlines, Inc., and Wilmington Trust
          Company, as Trustee, made with respect to the formation of
          America West Airlines Pass Through Trust, Series 1998-1C-S
          and the issuance of 7.84% Initial Pass Through Certificates,
          Series 1998-1C-S and 7.84% Exchange Pass Through
          Certificates, Series 1998-1C-S
  4.10    Revolving Credit Agreement, dated October 6, 1998, between
          Wilmington Trust Company, as Subordination Agent, as agent
          and trustee for the America West Airlines Pass Through Trust
          1998-1A, as Borrower; and ABN AMRO Bank N.V., Chicago
          Branch, as Liquidity Provider
  4.11    Revolving Credit Agreement, dated October 6, 1998, between
          Wilmington Trust Company, as Subordination Agent, as agent
          and trustee for the America West Airlines Pass Through Trust
          1998-1B, as Borrower; and ABN AMRO Bank N.V., Chicago
          Branch, as Liquidity Provider
  4.12    Revolving Credit Agreement, dated October 6, 1998, between
          Wilmington Trust Company, as Subordination Agent, as agent
          and trustee for the America West Airlines Pass Through Trust
          1998-1C, as Borrower; and ABN AMRO Bank N.V., Chicago
          Branch, as Liquidity Provider
</TABLE>
<PAGE>   136
 
<TABLE>
<CAPTION>
EXHIBIT                           DESCRIPTION
- -------                           -----------
<C>       <S>
  4.13    Intercreditor Agreement, dated as of October 6, 1998, among
          Wilmington Trust Company, as Trustee under the America West
          Airlines Pass Through Trust 1998-1A, America West Airlines
          Pass Through Trust 1998-1B and America West Airlines Pass
          Through Trust 1998-1C and ABN AMRO Bank N.V., Chicago
          Branch, as Class A Liquidity Provider, Class B Liquidity
          Provider and Class C Liquidity Provider, and Wilmington
          Trust Company, as Subordination Agent and Trustee
  4.14    Exchange and Registration Rights Agreement, dated as of
          October 6, 1998, among America West Airlines, Inc.;
          Wilmington Trust Company, as Trustee under America West
          Airlines Pass Through Trust, Series 1998-1A-O, America West
          Airlines Pass Through Trust, Series 1998-1B-O and
          AmericaWest Airlines Pass Through Trust, Series 1998-1C-O;
          and Morgan Stanley & Co. Incorporated, Donaldson, Lufkin &
          Jenrette Securities Corporation, Merrill Lynch, Pierce,
          Fenner & Smith Incorporated and Salomon Smith Barney Inc.
  4.15    Deposit Agreement (Class A), dated as of October 6, 1998,
          between Wilmington Trust Company, as Escrow Agent under the
          Escrow and Paying Agent Agreement, and ABN AMRO Bank N.V.,
          Chicago Branch, as Depositary
  4.16    Deposit Agreement (Class B), dated as of October 6, 1998,
          between Wilmington Trust Company, as Escrow Agent under the
          Escrow and Paying Agent Agreement, and ABN AMRO Bank N.V.,
          Chicago Branch, as Depositary
  4.17    Deposit Agreement (Class C), dated as of October 6, 1998,
          between Wilmington Trust Company as Escrow Agent under the
          Escrow and Paying Agent Agreement, and ABN AMRO Bank N.V.,
          Chicago Branch, as Depositary
  4.18    Escrow and Paying Agent Agreement (Class A), dated as of
          October 6, 1998, among Wilmington Trust Company, as Escrow
          Agent; Morgan Stanley & Co. Incorporated, Donaldson, Lufkin
          & Jenrette Securities Corporation, Merrill Lynch, Pierce,
          Fenner & Smith Incorporated and Salomon Smith Barney Inc.,
          as Initial Purchasers; Wilmington Trust Company, as Pass
          Through Trustee for and on behalf of America West Airlines
          Pass Through Trust 1998-1A-0; and Wilmington Trust Company
          as Paying Agent
  4.19    Escrow and Paying Agent Agreement (Class B), dated as of
          October 6, 1998, among Wilmington Trust Company, as Escrow
          Agent; Morgan Stanley & Co. Incorporated, Donaldson, Lufkin
          & Jenrette Securities Corporation, Merrill Lynch, Pierce,
          Fenner & Smith Incorporated and Salomon Smith Barney Inc.,
          as Initial Purchasers; Wilmington Trust Company, as Pass
          Through Trustee for and on behalf of America West Airlines
          Pass Through Trust 1998-1B-0; and Wilmington Trust Company
          as Paying Agent
  4.20    Escrow and Paying Agent Agreement (Class C), dated as of
          October 6, 1998, among Wilmington Trust Company, as Escrow
          Agent; Morgan Stanley & Co. Incorporated, Donaldson, Lufkin
          & Jenrette Securities Corporation, Merrill Lynch, Pierce,
          Fenner & Smith Incorporated and Salomon Smith Barney Inc.,
          as Initial Purchasers; Wilmington Trust Company, as Pass
          Through Trustee for and on behalf of America West Airlines
          Pass Through Trust 1998-1C-0; and Wilmington Trust Company
          as Paying Agent
  4.21    Note Purchase Agreement dated as of October 6, 1998, among
          America West Airlines, Inc., Wilmington Trust Company as
          Pass Through Trustee under each of the Pass Through Trust
          Agreements, and Wilmington Trust Company, as Subordination
          Agent, Escrow Agent and Paying Agent
  5.1     Opinion of Morris, James, Hitchens & Williams as to the
          legality of the New Certificates being registered hereby.
 12.1     Computation of ratio of earnings to fixed charges
 23.1     Consent of Morris, James, Hitchens & Williams (included in
          Exhibit 5.1)
 23.2     Consent of KPMG Peat Marwick LLP
 23.3     Consent of AVITAS, Inc.
 23.4     Consent of AvSolutions
 23.5     Consent of BK Associates, Inc.
</TABLE>
<PAGE>   137
 
<TABLE>
<CAPTION>
EXHIBIT                           DESCRIPTION
- -------                           -----------
<C>       <S>
 24.1     Power of Attorney (see signature page in Part II of
          Registration Statement)
 25.1     Statement of Eligibility of Wilmington Trust Company for the
          1998-1A Pass Through Certificates, on Form T-1
 25.2     Statement of Eligibility of Wilmington Trust Company for the
          1998-1B Pass Through Certificates, on Form T-1
 25.3     Statement of Eligibility of Wilmington Trust Company for the
          1998-1C Pass Through Certificates, on Form T-1
 99.1     Form of Letter of Transmittal
 99.2     Form of Notice of Guaranteed Delivery
 99.3     Form of Letter to Brokers, Dealers, Commercial Banks, Trust
          Companies and Other Nominees
 99.4     Form of Letter to Clients
</TABLE>

<PAGE>   1
                                                                     Exhibit 4.4


                          PASS THROUGH TRUST AGREEMENT

                           Dated as of October 6, 1998

                                     between

                           AMERICA WEST AIRLINES, INC.

                                       and

                            WILMINGTON TRUST COMPANY,

                                   as Trustee

           America West Airlines Pass Through Trust, Series 1998-1A-O

            6.87% Initial Pass Through Certificates, Series 1998-1A-O
           6.87% Exchange Pass Through Certificates, Series 1998-1A-O
<PAGE>   2
Reconciliation and tie between America West Airlines Pass Through Trust
Agreement, Series 1998-1A-O dated as of October 6, 1998, and the Trust Indenture
Act of 1939. This reconciliation does not constitute part of the Pass Through
Trust Agreement.

                  Trust Indenture Act            Pass Through Trust
                   of 1939 Section               Agreement Section
                   ---------------               -----------------
                  310(a)(1)                          7.08
                     (a)(2)                          7.08
                  312(a)                             3.05; 8.01; 8.02
                  313(a)                             7.06; 8.03
                  314(a)                             8.04(a),(c) & (d)
                  (a)(4)                             8.04(e)
                  (c)(1)                             1.02
                  (c)(2)                             1.02
                  (d)(1)                             7.13; 11.01
                  (d)(2)                             7.13; 11.01
                  (d)(3)                             2.01
                  (e)                                1.02
                  315(b)                             7.02
                  316(a)(last sentence)              1.04(c)
                     (a)(1)(A)                       6.04
                     (a)(1)(B)                       6.05
                     (b)                             6.06
                     (c)                             1.04(e)
                  317(a)(1)                          6.03
                     (b)                             7.13
                  318(a)                             12.06
<PAGE>   3
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
SECTION                                                                                                        PAGE

<S>                                                                                                           <C>
ARTICLE I  DEFINITIONS............................................................................................2       
         Section 1.01.     Definitions............................................................................2
         Section 1.02.     Compliance Certificates and Opinions..................................................13
         Section 1.03.     Form of Documents Delivered to Trustee................................................14
         Section 1.04.     Directions of Certificateholders......................................................14

ARTICLE II  ORIGINAL ISSUANCE OF CERTIFICATES; ACQUISITION OF EQUIPMENT NOTES....................................16
         Section 2.01.     Issuance of Certificates; Acquisition of Equipment Notes..............................16
         Section 2.02.     Withdrawal of Deposits................................................................17
         Section 2.03.     Acceptance by Trustee.................................................................17
         Section 2.04.     Limitation of Powers..................................................................17

ARTICLE III  THE CERTIFICATES....................................................................................17
         Section 3.01.     Title, Form, Denomination and Execution of Certificates...............................17
         Section 3.02.     Restrictive Legends...................................................................19
         Section 3.03.     Authentication of Certificates........................................................21
         Section 3.04.     Transfer and Exchange.................................................................21
         Section 3.05.     Book-Entry Provisions for Restricted Global Certificates and Regulation S
                           Global Certificates...................................................................22
         Section 3.06.     Special Transfer Provisions...........................................................24
         Section 3.07.     Mutilated, Destroyed, Lost or Stolen Certificates.....................................26
         Section 3.08.     Persons Deemed Owners.................................................................27
         Section 3.09.     Cancellation..........................................................................27
         Section 3.10.     Temporary Certificates................................................................27
         Section 3.11.     Limitation of Liability for Payments..................................................28

ARTICLE IV  DISTRIBUTIONS; STATEMENTS TO CERTIFICATEHOLDERS......................................................28
         Section 4.01.     Certificate Account and Special Payments Account......................................28
         Section 4.02.     Distributions from Certificate Account and Special Payments Account...................29
         Section 4.03.     Statements to Certificateholders......................................................30
         Section 4.04.     Investment of Special Payment Moneys..................................................31

ARTICLE V  THE COMPANY...........................................................................................32   
         Section 5.01.     Maintenance of Corporate Existence....................................................32
         Section 5.02.     Consolidation, Merger, etc............................................................32

ARTICLE VI  DEFAULT..............................................................................................33
         Section 6.01.     Events of Default.....................................................................33
         Section 6.02.     Incidents of Sale of Equipment Notes..................................................35
         Section 6.03.     Judicial Proceedings Instituted by Trustee; Trustee May Bring Suit....................35
         Section 6.04      Control by Certificateholders.........................................................36
</TABLE>
<PAGE>   4
<TABLE>
<CAPTION>
SECTION                                                                                                        PAGE

<S>                                                                                                             <C>
         Section 6.05.     Waiver of Past Defaults...............................................................36
         Section 6.06.     Right of Certificateholders to Receive Payments Not to Be Impaired....................37
         Section 6.07.     Certificateholders May Not Bring Suit Except Under Certain Conditions.................37
         Section 6.08.     Remedies Cumulative...................................................................37

ARTICLE VII  THE TRUSTEE.........................................................................................38
         Section 7.01.     Certain Duties and Responsibilities...................................................38
         Section 7.02.     Notice of Defaults....................................................................38
         Section 7.03.     Certain Rights of Trustee.............................................................38
         Section 7.04.     Not Responsible for Recitals or Issuance of Certificates..............................39
         Section 7.05.     May Hold Certificates.................................................................40
         Section 7.06.     Money Held in Trust...................................................................40
         Section 7.07.     Compensation and Reimbursement........................................................40
         Section 7.08.     Corporate Trustee Required; Eligibility...............................................41
         Section 7.09      Resignation and Removal; Appointment of Successor.....................................42
         Section 7.10.     Acceptance of Appointment by Successor................................................43
         Section 7.11.     Merger, Conversion, Consolidation or Succession to Business...........................43
         Section 7.12.     Maintenance of Agencies...............................................................44
         Section 7.13.     Money for Certificate Payments to Be Held in Trust....................................45
         Section 7.14.     Registration of Equipment Notes in Name of Subordination Agent........................45
         Section 7.15.     Representations and Warranties of Trustee.............................................45
         Section 7.16.     Withholding Taxes, Information Reporting..............................................46
         Section 7.17.     Trustee's Liens.......................................................................47
         Section 7.18.     Preferential Collection of Claims.....................................................47

ARTICLE VIII  CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE...................................................47
         Section 8.01.     The Company to Furnish Trustee with Names and Addresses of Certificateholders.........47
         Section 8.02.     Preservation of Information; Communications to Certificateholders.....................48
         Section 8.03.     Reports by Trustee....................................................................48
         Section 8.04.     Reports by the Company................................................................48

ARTICLE IX  SUPPLEMENTAL AGREEMENTS..............................................................................49
         Section 9.01.     Supplemental Agreements Without Consent of Certificateholders.........................49
         Section 9.02.     Supplemental Agreements with Consent of Certificateholders............................50
         Section 9.03.     Documents Affecting Immunity or Indemnity.............................................51
         Section 9.04.     Execution of Supplemental Agreements..................................................51
         Section 9.05.     Effect of Supplemental Agreements.....................................................52
         Section 9.06.     Conformity with Trust Indenture Act...................................................52
         Section 9.07.     Reference in Certificates to Supplemental Agreements..................................52

ARTICLE X  AMENDMENTS TO INDENTURES AND FINANCING DOCUMENTS......................................................52
         Section 10.01.    Amendments and Supplements to Indentures and Financing Documents......................52
</TABLE>

                                       ii
<PAGE>   5
<TABLE>
<CAPTION>
SECTION                                                                                                        PAGE

<S>                                                                                                             <C>
ARTICLE XI  TERMINATION OF TRUST.................................................................................53
         Section 11.01.    Termination of the Trust..............................................................53

ARTICLE XII  MISCELLANEOUS PROVISIONS............................................................................55
         Section 12.01.    Limitation on Rights of Certificateholders............................................55
         Section 12.02.    Certificates Nonassessable and Fully Paid.............................................55
         Section 12.03.    Notices...............................................................................56
         Section 12.04.    Governing Law.........................................................................57
         Section 12.05.    Severability of Provisions............................................................57
         Section 12.06.    Trust Indenture Act Controls..........................................................57
         Section 12.07.    Effect of Headings and Table of Contents..............................................57
         Section 12.08.    Successors and Assigns................................................................57
         Section 12.09.    Benefits of Agreement.................................................................57
         Section 12.10.    Legal Holidays........................................................................57
         Section 12.11.    Counterparts..........................................................................57
         Section 12.12.    Intention of Parties..................................................................58


Exhibit A           -      Form of Certificate
Exhibit B           -      Form of Certificate to Request Removal of Restricted Legend
Exhibit C           -      Form of Certificate to be Delivered by an Institutional Accredited Investor
Exhibit D           -      Form of Assignment and Assumption Agreement
Exhibit E           -      Form of Notice to Withholding Agent
</TABLE>

                                      iii
<PAGE>   6
                          PASS THROUGH TRUST AGREEMENT


                  This PASS THROUGH TRUST AGREEMENT, dated as of October 6, 1998
(the "Agreement"), between AMERICA WEST AIRLINES, INC., a Delaware corporation,
and WILMINGTON TRUST COMPANY, as Trustee, is made with respect to the formation
of America West Airlines Pass Through Trust, Series 1998-1A-O and the issuance
of 6.87% America West Airlines Pass Through Trust, Series 1998-1A-O Pass Through
Certificates representing fractional undivided interests in the Trust.

                                   WITNESSETH:

                  WHEREAS, the Company has obtained commitments from AVSA for
the delivery of certain Aircraft;

                  WHEREAS, the Company intends to finance (or refinance) the
acquisition of the Aircraft either (i) through separate leveraged lease
transactions in which the Company will lease such aircraft (collectively, the
"Leased Aircraft") or (ii) through separate secured loan transactions in which
the Company will own such Aircraft (collectively, the "Owned Aircraft");

                  WHEREAS, in the case of each Leased Aircraft, each Owner
Trustee, acting on behalf of the corresponding Owner Participant, will issue
pursuant to an Indenture, on a non-recourse basis, three series (or, subject to
satisfaction of certain preconditions contained in the Note Purchase Agreement,
four) of Equipment Notes in order to finance a portion of its purchase price of
such Leased Aircraft;

                  WHEREAS, in the case of each Owned Aircraft, the Company will
issue pursuant to an Indenture, on a recourse basis, three (or, subject to
satisfaction of certain preconditions contained in the Note Purchase Agreement,
four) series of Equipment Notes to finance a portion of the purchase price of
such Owned Aircraft;

                  WHEREAS, the Trustee, upon execution and delivery of this
Agreement, hereby declares the creation of the Trust for the benefit of the
Certificateholders, and the initial Certificateholders, as the grantors of the
Trust, by their respective acceptances of the Certificates, join in the creation
of this Trust with the Trustee;

                  WHEREAS, all Certificates to be issued by the Trust will
evidence fractional undivided interests in the Trust and will convey no rights,
benefits or interests in respect of any property other than the Trust Property
except for those Certificates to which an Escrow Receipt has been affixed;

                  WHEREAS, the Escrow Agent and the Initial Purchasers have
contemporaneously herewith entered into an Escrow Agreement with the Escrow
Paying Agent pursuant to which the Initial Purchasers have delivered to the
Escrow Agent the proceeds from the sale of the Certificates and have irrevocably
instructed the Escrow Agent to withdraw and pay funds from such proceeds upon
request and proper certification by the Trustee to purchase Equipment Notes;
<PAGE>   7
                                      -2-

                  WHEREAS, the Escrow Agent on behalf of the Certificateholders
has contemporaneously herewith entered into a Deposit Agreement with the
Depositary under which the Deposits referred to therein will be made and from
which it will withdraw funds to allow the Trustee to purchase Equipment Notes
from time to time prior to the Delivery Period Termination Date;

                  WHEREAS, pursuant to the terms and conditions of this
Agreement and the Note Purchase Agreement, upon or following delivery of an
Aircraft, the Trustee on behalf of the Trust, using funds withdrawn under the
Escrow Agreement, may purchase an Equipment Note having the same interest rate
as, and final legal distribution date not later than the final Regular
Distribution Date of, the Certificates issued hereunder and shall hold such
Equipment Note in trust for the benefit of the Certificateholders;

                  WHEREAS, to facilitate the sale of Equipment Notes to, and the
purchase of Equipment Notes by, the Trustee on behalf of the Trust, the Company
has duly authorized the execution and delivery of this Agreement as the
"issuer", as such term is defined in and solely for purposes of the Securities
Act, of the Certificates to be issued pursuant hereto and as the "obligor", as
such term is defined in and solely for purposes of the Trust Indenture Act of
1939, as amended, with respect to all such Certificates and is undertaking to
perform certain administrative and ministerial duties hereunder and is also
undertaking to pay the ongoing fees and expenses of the Trustee;

                  WHEREAS, all of the conditions and requirements necessary to
make this Agreement, when duly executed and delivered, a valid, binding and
legal instrument, enforceable in accordance with its terms and for the purposes
herein expressed, have been done, performed and fulfilled, and the execution and
delivery of this Agreement in the form and with the terms hereof have been in
all respects duly authorized; and

                  WHEREAS, upon issuance of the Exchange Certificates, if any,
or the effectiveness of the Shelf Registration Statement, this Agreement, as
amended or supplemented from time to time, will be subject to the provisions of
the Trust Indenture Act of 1939, and shall, to the extent applicable, be
governed by such provisions;

                  NOW, THEREFORE, in consideration of the mutual agreements
herein contained, and of other good and valuable consideration the receipt and
adequacy of which are hereby acknowledged, the parties hereto agree as follows:


                                    ARTICLE I

                                   DEFINITIONS

                  Section 1.01. Definitions. For all purposes of this Agreement,
except as otherwise expressly provided or unless the context otherwise requires:

                  (1) the terms used in this Agreement, including in the
         recitals to this Agreement, that are defined in this Article have the
         meanings assigned to them in this Article, and include the plural as
         well as the singular;
<PAGE>   8
                                       -3-


                  (2) all other terms used herein which are defined in the Trust
         Indenture Act, either directly or by reference therein, or by the rules
         promulgated under the Trust Indenture Act, have the meanings assigned
         to them therein;

                  (3) all references in this Agreement to designated "Articles",
         "Sections", "Subsections" and other subdivisions are to the designated
         Articles, Sections, Subsections and other subdivisions of this
         Agreement;

                  (4) the words "herein", "hereof" and "hereunder" and other
         words of similar import refer to this Agreement as a whole and not to
         any particular Article, Section, SubSection or other subdivision; and

                  (5) unless the context otherwise requires, whenever the words
         "including", "include" or "includes" are used herein, it shall be
         deemed to be followed by the phrase "without limitation".

                  Affiliate: Means, with respect to any specified Person, any
         other Person directly or indirectly controlling or controlled by or
         under direct or indirect common control with such Person. For the
         purposes of this definition, "control" means the power, directly or
         indirectly, to direct the management and policies of such Person,
         whether through the ownership of voting securities or by contract or
         otherwise, and the terms "controlling" and "controlled" have meanings
         correlative to the foregoing.

                  Agent Members: Has the meaning specified in Section 3.05.

                  Agreement: Has the meaning specified in the initial paragraph
         hereto.

                  Aircraft: Has the meaning specified in the Note Purchase
         Agreement.

                  Aircraft Purchase Agreement: Has the meaning specified in the
         Note Purchase Agreement.

                  Applicable Delivery Date: Has the meaning specified in Section
         2.01(b).

                  Applicable Participation Agreement: Has the meaning specified
         in Section 2.01(b).

                  Assignment and Assumption Agreement: Means the assignment and
         assumption agreement substantially in the form of Exhibit D hereto to
         be executed and delivered in accordance with Section 11.01.

                  Authorized Agent: Means any Paying Agent or Registrar for the
         Certificates.

                  Avoidable Tax: Means a state or local tax (i) upon (w) the
         Trust, (x) the Trust Property, (y) Certificate-holders or (z) the
         Trustee for which the Trustee is entitled to seek reimbursement from
         the Trust Property, and (ii) which would be avoided if the Trustee were
         located in another state, or jurisdiction within a state, within the
         United 
<PAGE>   9
                                      -4-


         States. A tax shall not be an Avoidable Tax if the Company or any Owner
         Trustee shall agree to pay, and shall pay, such tax.

                  AVSA: Means AVSA S.A.R.L., an affiliate of Airbus Industrie
         G.I.E.

                  Business Day: Means any day other than a Saturday, a Sunday or
         a day on which commercial banks are required or authorized to close in
         Phoenix, Arizona, New York, New York, Wilmington, Delaware or, so long
         as any Certificate is outstanding, the city and state in which the
         Trustee or any Loan Trustee maintains its Corporate Trust Office or
         receives and disburses funds.

                  Cedel: Means Cedel Bank societe anonyme.

                  Certificate: Means any one of the Initial Certificates or
         Exchange Certificates and any such Certificates issued in exchange
         therefor or replacement thereof pursuant to this Agreement.

                  Certificate Account: Means the account or accounts created and
         maintained pursuant to Section 4.01(a).

                  Certificate Purchase Agreement: Means the Purchase Agreement
         dated September 24, 1998 among the Initial Purchasers and the Company,
         as the same may be amended, supplemented or otherwise modified from
         time to time in accordance with its terms.

                  Certificateholder or Holder: Means the Person in whose name a
         Certificate is registered in the Register.

                  Class D Certificateholder: Means, at any time, any holder of
         one or more pass through certificates issued by the America West
         Airlines Pass Through Trust, Series 1998-1D, if and when established.

                  Company: Means America West Airlines, Inc., a Delaware
         corporation, or its successor in interest pursuant to Section 5.02, or
         (only in the context of provisions hereof, if any, where such reference
         is required for purposes of compliance with the Trust Indenture Act)
         any other "obligor" (within the meaning of the Trust Indenture Act)
         with respect to the Certificates.

                  Controlling Party: Has the meaning specified in the
         Intercreditor Agreement.

                  Corporate Trust Office: With respect to the Trustee or any
         Loan Trustee, means the office of such trustee in the city at which at
         any particular time its corporate trust business shall be principally
         administered.

                  Cut-off Date: Means the earlier of (a) the Delivery Period
         Termination Date and (b) the date on which a Triggering Event occurs.

                  Definitive Certificates: Has the meaning specified in Section
         3.01(e).
<PAGE>   10
                                      -5-


                  Delivery Date: Has the meaning specified in the Note Purchase
         Agreement.

                  Delivery Notice: Has the meaning specified in the Note
         Purchase Agreement.

                  Delivery Period Termination Date: Means the earlier of (a)
         November 30, 1999, or, if the Equipment Notes relating to all of the
         Aircraft (or Substitute Aircraft in lieu thereof) have not been
         purchased by the Trustee and the Other Trustees on or prior to such
         date due to any reason beyond the control of the Company and not
         occasioned by the Company's fault or negligence, January 31, 2000 and
         (b) the date on which Equipment Notes issued with respect to all of the
         Aircraft (or Substitute Aircraft in lieu thereof) have been purchased
         by the Trustee and the Other Trustees in accordance with the Note
         Purchase Agreement.

                  Deposits:  Has the meaning specified in the Deposit Agreement.

                  Deposit Agreement: Means the Deposit Agreement dated as of
         October 6, 1998 relating to the Certificates between the Depositary and
         the Escrow Agent, as the same may be amended, supplemented or otherwise
         modified from time to time in accordance with its terms.

                  Depositary: Means ABN AMRO Bank N.V., acting through its
         Chicago branch. 

                  Direction: Has the meaning specified in Section 1.04(a).

                  Distribution Date: Means any Regular Distribution Date or
         Special Distribution Date as the context requires.

                  DTC: Means The Depository Trust Company, its nominees and
         their respective successors.

                  EBO Date: Means the date set forth on Schedule 1 to the Lease
         as the "EBO Date".

                  Equipment Notes: Means the equipment notes issued under the
         Indentures.

                  Escrow Agent:  Means, initially, Wilmington Trust Company.

                  Escrow Agreement: Means the Escrow and Paying Agent Agreement
         dated as of October 6, 1998 relating to the Certificates, among the
         Escrow Agent, the Escrow Paying Agent, the Trustee and the Initial
         Purchasers, as the same may be amended, supplemented or otherwise
         modified from time to time in accordance with its terms.

                  Escrow Paying Agent: Means the Person acting as paying agent
         under the Escrow Agreement.

                  Escrow Receipt: Means the receipt substantially in the form
         annexed to the Escrow Agreement representing a fractional undivided
         interest in the funds held in escrow thereunder.
<PAGE>   11
                                      -6-


                  Euroclear: Means Morgan Guaranty Trust Company of New York,
         Brussels Office, as operator of the Euroclear System.

                  Event of Default: Means an Indenture Default under any
         Indenture pursuant to which Equipment Notes held by the Trust were
         issued.

                  Exchange Certificates: Means the pass through certificates
         substantially in the form of Exhibit A hereto issued in exchange for
         the Initial Certificates pursuant to the Registration Rights Agreement
         and authenticated hereunder.

                  Exchange Offer: Means the exchange offer which may be made
         pursuant to the Registration Rights Agreement to exchange Initial
         Certificates for Exchange Certificates.

                  Exchange Offer Registration Statement: Means the registration
         statement that, pursuant to the Registration Rights Agreement, is filed
         by the Company with the SEC with respect to the exchange of Initial
         Certificates for Exchange Certificates.

                  Final Legal Distribution Date:  Means July 2, 2018.

                  Final Withdrawal: Has the meaning specified in the Escrow
         Agreement.

                  Final Withdrawal Date: Has the meaning specified in the Escrow
         Agreement.

                  Final Withdrawal Notice: Has the meaning specified in Section
         2.02.

                  Financing Documents: With respect to any Equipment Note, means
         (i) the Indenture and the Participation Agreement relating to such
         Equipment Note, and (ii) in the case of any Equipment Note related to a
         Leased Aircraft, the Lease relating to such Leased Aircraft.

                  Fractional Undivided Interest: Means the fractional undivided
         interest in the Trust that is evidenced by a Certificate.

                  Global Certificates: Has the meaning specified in Section
         3.01(d).

                  Global Exchange Certificate: Has the meaning specified in
         Section 3.01(f).

                  Indenture: Means each of the separate trust indentures and
         mortgages relating to the Aircraft, each as specified or described in a
         Delivery Notice delivered pursuant to the Note Purchase Agreement or
         the related Participation Agreement, in each case as the same may be
         amended, supplemented or otherwise modified from time to time in
         accordance with its terms.

                  Indenture Default: With respect to any Indenture, means any
         Event of Default (as such term is defined in such Indenture).

                  Initial Certificates: Means the certificates issued and
         authenticated hereunder substantially in the form of Exhibit A hereto
         other than the Exchange Certificates.
<PAGE>   12
                                      -7-


                  Initial Purchasers: Means, collectively, Morgan Stanley & Co.
         Incorporated, Donaldson, Lufkin & Jenrette Securities Corporation,
         Merrill, Lynch, Pierce, Fenner & Smith Incorporated and Salomon Smith
         Barney Inc.

                  Institutional Accredited Investor: Means an institutional
         investor that is an "accredited investor" within the meaning set forth
         in Rule 501(a)(1), (2), (3) or (7) of Regulation D under the Securities
         Act.

                  Intercreditor Agreement: Means the Intercreditor Agreement
         dated as of October 6, 1998 among the Trustee, the Other Trustees, the
         Liquidity Provider, the liquidity provider relating to the Certificates
         issued under (and as defined in) each of the Other Pass Through Trust
         Agreements, and Wilmington Trust Company, as Subordination Agent and as
         trustee thereunder, as amended, supplemented or otherwise modified from
         time to time in accordance with its terms.

                  Investors: Means the Initial Purchasers together with all
         subsequent beneficial owners of the Certificates.

                  Issuance Date: Means the date of the issuance of the Initial
         Certificates.

                  Lease: Means, with respect to each Leased Aircraft, the lease
         between an Owner Trustee, as the lessor, and the Company, as the
         lessee, referred to in the related Indenture, as such lease may be
         amended, supplemented or otherwise modified in accordance with its
         terms.

                  Leased Aircraft: Has the meaning specified in the second
         recital to this Agreement.

                  Liquidity Facility: Means, initially, the Revolving Credit
         Agreement dated as of October 6, 1998 relating to the Certificates,
         between the Liquidity Provider and the Subordination Agent, as agent
         and trustee for the Trustee, and, from and after the replacement of
         such Agreement pursuant to the Intercreditor Agreement, the replacement
         liquidity facility therefor, in each case as amended, supplemented or
         otherwise modified from time to time in accordance with their
         respective terms.

                  Liquidity Provider: Means, initially, ABN AMRO Bank N.V.,
         acting through its Chicago branch and any replacement or successor
         therefor appointed in accordance with the Intercreditor Agreement.

                  Loan Trustee: With respect to any Equipment Note or the
         Indenture applicable thereto, means the bank or trust company
         designated as trustee under such Indenture, together with any successor
         to such trustee appointed pursuant thereto.

                  Material Adverse Tax Event: Has the meaning specified in
         Section 17.3(a)(4) of the Lease.

                  Non-U.S. Person: Means a Person that is not a "U.S. person",
         as defined in Regulation S.
<PAGE>   13
                                      -8-


                  Note Purchase Agreement: Means the Note Purchase Agreement
         dated as of October 6, 1998 among the Trustee, the Other Trustees, the
         Company, the Escrow Agent, the Escrow Paying Agent and the
         Subordination Agent, providing for, among other things, the purchase of
         Equipment Notes by the Trustee on behalf of the Trust, as the same may
         be amended, supplemented or otherwise modified from time to time, in
         accordance with its terms.

                  Notice of Purchase Withdrawal: Has the meaning specified in
         the Deposit Agreement.

                  Offering Circular: Means the Offering Memorandum dated
         September 24, 1998 relating to the offering of the Certificates and the
         certificates issued under the Other Pass Through Trust Agreements.

                  Officer's Certificate: Means a certificate signed, (a) in the
         case of the Company, by any Vice President or more senior officer of
         the Company or, (b) in the case of an Owner Trustee or a Loan Trustee,
         a Responsible Officer of such Owner Trustee or such Loan Trustee, as
         the case may be.

                  Opinion of Counsel: Means a written opinion of legal counsel
         who (a) in the case of counsel for the Company may be (i) the General
         Counsel of the Company, (ii) Cooley Godward LLP, (iii) Vedder, Price,
         Kaufman, Kammholz & Day, or (iv) such other counsel designated by the
         Company and reasonably acceptable to the Trustee and (b) in the case of
         counsel for any Owner Trustee or any Loan Trustee may be such counsel
         as may be designated by any of them whether or not such counsel is an
         employee of any of them, and who shall be reasonably acceptable to the
         Trustee.

                  Other Pass Through Trust Agreements: Means each of the two
         other America West Airlines 1998-1 Pass Through Trust Agreements
         relating to America West Airlines Pass Through Trust, Series 1998-1B-O
         and America West Airlines Pass Through Trust, Series 1998-1C-O, dated
         the date hereof.

                  Other Trustees: Means the trustees under the Other Pass
         Through Trust Agreements, and any successor or other trustee appointed
         as provided therein.

                  Other Trusts: Means the America West Airlines Pass Through
         Trust, Series 1998-1B-O and America West Airlines Pass Through Trust,
         Series 1998-1C-O, created on the date hereof.

                  Outstanding: When used with respect to Certificates, means, as
         of the date of determination, all Certificates theretofore
         authenticated and delivered under this Agreement, except:

                           (i) Certificates theretofore canceled by the
                  Registrar or delivered to the Trustee or the Registrar for
                  cancellation;

                           (ii) Certificates for which money in the full amount
                  required to make the final distribution with respect to such
                  Certificates pursuant to Section 11.01 
<PAGE>   14
                                      -9-


                  hereof has been theretofore deposited with the Trustee in
                  trust for the Holders of such Certificates as provided in
                  Section 4.01 pending distribution of such money to such
                  Certificateholders pursuant to payment of such final
                  distribution; and

                           (iii) Certificates in exchange for or in lieu of
                  which other Certificates have been authenticated and delivered
                  pursuant to this Agreement.

                  Owned Aircraft: Has the meaning specified in the second
         recital to this Agreement.

                  Owner Participant: With respect to any Equipment Note relating
         to a Leased Aircraft, means the "Owner Participant" as referred to in
         the Indenture pursuant to which such Equipment Note is issued and any
         permitted successor or assign of such Owner Participant; and Owner
         Participants at any time of determination means all of the Owner
         Participants thus referred to in the Indentures.

                  Owner Trustee: With respect to any Equipment Note relating to
         a Leased Aircraft, means the "Owner Trustee", as referred to in the
         Indenture pursuant to which such Equipment Note is issued, not in its
         individual capacity but solely as trustee; and Owner Trustees means all
         of the Owner Trustees party to any of the Indentures.

                  Participation Agreement: Means each Participation Agreement to
         be entered into by the Trustee pursuant to the Note Purchase Agreement,
         as the same may be amended, supplemented or otherwise modified in
         accordance with its terms.

                  Paying Agent: Means the paying agent maintained and appointed
         for the Certificates pursuant to Section 7.12.

                  Permitted Investments: Means obligations of the United States
         of America or agencies or instrumentalities thereof for the payment of
         which the full faith and credit of the United States of America is
         pledged, maturing in not more than 60 days after the date of
         acquisition thereof or such lesser time as is required for the
         distribution of any Special Payments on a Special Distribution Date.

                  Person: Means any person, including any individual,
         corporation, limited liability company, partnership, joint venture,
         association, joint-stock company, trust, trustee, unincorporated
         organization, or government or any agency or political subdivision
         thereof.

                  Pool Balance: Means, as of any date, (i) the original
         aggregate face amount of the Certificates less (ii) the aggregate
         amount of all payments made in respect of such Certificates other than
         payments made in respect of interest or premium thereon or
         reimbursement of any costs or expenses incurred in connection therewith
         less (iii) the aggregate amount of unused Deposits distributed as a
         Final Withdrawal other than payments in respect of interest or premium
         thereon. The Pool Balance as of any Distribution Date shall be computed
         after giving effect to the payment of principal, if any, on the
         Equipment Notes or other Trust Property held in such Trust and the
<PAGE>   15
                                      -10-


         distribution thereof to be made on such Distribution Date and the
         distribution of the Final Withdrawal to be made on such Distribution
         Date.

                  Pool Factor: Means, as of any date, the quotient (rounded to
         the seventh decimal place) computed by dividing (i) the Pool Balance as
         at such date by (ii) the original aggregate face amount of the
         Certificates. The Pool Factor as of any Distribution Date shall be
         computed after giving effect to the payment of principal, if any, on
         the Equipment Notes or other Trust Property and the distribution
         thereof to be made on such Distribution Date and the distribution of
         the Final Withdrawal to be made on such Distribution Date.

                  PTC Event of Default: Means any failure to pay within 10
         Business Days of the due date thereof: (i) the outstanding Pool Balance
         on the Final Legal Distribution Date or (ii) interest due on the
         Certificates on any Distribution Date (unless the Subordination Agent
         shall have made an Interest Drawing or Drawings (as defined in the
         Intercreditor Agreement), or a withdrawal or withdrawals pursuant to
         Section 3.6(f) of the Intercreditor Agreement, with respect thereto in
         an aggregate amount sufficient to pay such interest and shall have
         distributed such amount to the Trustee).

                  QIB: Means a qualified institutional buyer as defined in Rule
         144A.

                  Record Date: Means (i) for Scheduled Payments to be
         distributed on any Regular Distribution Date, other than the final
         distribution, the 15th day (whether or not a Business Day) preceding
         such Regular Distribution Date, and (ii) for Special Payments to be
         distributed on any Special Distribution Date, other than the final
         distribution, the 15th day (whether or not a Business Day) preceding
         such Special Distribution Date.

                  Register and Registrar: Mean the register maintained and the
         registrar appointed pursuant to Sections 3.04 and 7.12.

                  Registration Event: Means the declaration of the effectiveness
         by the SEC of the Exchange Offer Registration Statement or the Shelf
         Registration Statement.

                  Registration Rights Agreement: Means the Exchange and
         Registration Rights Agreement dated as of October 6, 1998, among the
         Initial Purchasers, the Trustee, the Other Trustees and the Company, as
         amended, supplemented or otherwise modified from time to time in
         accordance with its terms.

                  Regular Distribution Date: With respect to distributions of
         Scheduled Payments in respect of the Certificates, means each date
         designated as a Regular Distribution Date in the Certificates issued
         pursuant to this Agreement, until payment of all the Scheduled Payments
         to be made under the Equipment Notes held in the Trust have been made;
         provided, however, that, if any such day shall not be a Business Day,
         the related distribution shall be made on the next succeeding Business
         Day without additional interest.

                  Regulation S: Means Regulation S under the Securities Act or
         any successor regulation thereto.
<PAGE>   16
                                      -11-


                  Regulation S Definitive Certificates: Has the meaning
         specified in Section 3.01(e).

                  Regulation S Global Certificates: Has the meaning specified in
         Section 3.01(d).

                  Related Pass Through Trust Agreement: Means the Pass Through
         Trust Agreement relating to America West Airlines Pass Through Trust,
         Series 1998-1A-S, dated the date hereof, between the Company and the
         institution acting as trustee thereunder, which agreement becomes
         effective upon the execution and delivery of the Assignment and
         Assumption Agreement pursuant to Section 11.01.

                  Related Trust: Means the America West Pass Through Trust,
         Series 1998-1A-S, formed under the Related Pass Through Trust
         Agreement.

                  Related Trustee: Means the trustee under the Related Pass
         Through Trust Agreement.

                  Responsible Officer: With respect to the Trustee, any Loan
         Trustee and any Owner Trustee, means any officer in the Corporate Trust
         Office of the Trustee, Loan Trustee or Owner Trustee or any other
         officer customarily performing functions similar to those performed by
         the persons who at the time shall be such officers, respectively, or to
         whom any corporate trust matter is referred because of his knowledge of
         and familiarity with a particular subject.

                  Restricted Definitive Certificates: Has the meaning specified
         in Section 3.01(e).

                  Restricted Global Certificate: Has the meaning specified in
         Section 3.01(c).

                  Restricted Legend: Has the meaning specified in Section 3.02.

                  Restricted Period: Has the meaning specified in Section
         3.01(d).

                  Rule 144A: Means Rule 144A under the Securities Act and any
         successor rule thereto.

                  Scheduled Payment: With respect to any Equipment Note, means
         (i) any payment of principal or interest on such Equipment Note (other
         than any such payment which is not in fact received by the
         Subordination Agent within five days of the date on which such payment
         is scheduled to be made) due from the obligor thereon or (ii) any
         payment of interest on the Certificates with funds drawn under any
         Liquidity Facility, which payment represents the installment of
         principal at the stated maturity of such installment of principal on
         such Equipment Note, the payment of regularly scheduled interest
         accrued on the unpaid principal amount of such Equipment Note, or both;
         provided that any payment of principal, premium, if any, or interest
         resulting from the redemption or purchase of any Equipment Note shall
         not constitute a Scheduled Payment.

                  SEC: Means the Securities and Exchange Commission, as from
         time to time constituted or created under the United States Securities
         Exchange Act of 1934, as 
<PAGE>   17
                                      -12-


         amended, or, if at any time after the execution of this instrument such
         Commission is not existing and performing the duties now assigned to it
         under the Trust Indenture Act, then the body performing such duties on
         such date.

                  Securities Act: Means the United States Securities Act of
         1933, as amended from time to time, or any successor thereto.

                  Shelf Registration Statement: Means the shelf registration
         statement which may be required to be filed by the Company with the SEC
         pursuant to any Registration Rights Agreement, other than an Exchange
         Offer Registration Statement.

                  Special Distribution Date: Means each date on which a Special
         Payment is to be distributed as specified in this Agreement; provided,
         however, that, if any such day shall not be a Business Day, the related
         distribution shall be made on the next succeeding Business Day without
         additional interest.

                  Special Redemption Premium: Means the premium payable by the
         Company in respect of the Final Withdrawal pursuant to the Note
         Purchase Agreement.

                  Special Payment: Means any payment (other than a Scheduled
         Payment) in respect of, or any proceeds of, any Equipment Note or Trust
         Indenture Estate (as defined in each Indenture) or Special Redemption
         Premium.

                  Special Payments Account: Means the account or accounts
         created and maintained pursuant to Section 4.01(b).

                  Subordination Agent: Has the meaning specified in the
         Intercreditor Agreement.

                  Substitute Aircraft: Has the meaning specified in the Note
         Purchase Agreement.

                  Tax: Means all license, recording, documentary, registration
         and other similar fees and all taxes, levies, imposts, duties, charges,
         assessments or withholdings of any nature whatsoever imposed by any
         Taxing Authority, together with any penalties, additions to tax, fines
         or interest thereon or additions thereto.

                  Taxing Authority: Means any federal, state or local government
         or other taxing authority in the United States, any foreign government
         or any political subdivision or taxing authority thereof, any
         international taxing authority or any territory or possession of the
         United States or any taxing authority thereof.

                  TIN:  Has the meaning specified in Section 7.16.

                  Transfer Date:  Has the meaning specified in Section 11.01.

                  Triggering Event: Has the meaning assigned to such term in the
         Intercreditor Agreement.
<PAGE>   18
                                      -13-

               
                  Trust: Means the trust created by this Agreement, the estate
         of which consists of the Trust Property.

                  Trust Indenture Act: Means the United States Trust Indenture
         Act of 1939, as amended from time to time, or any successor thereto.

                  Trust Property: Means (i) the Equipment Notes held as the
         property of the Trust and, subject to the Intercreditor Agreement, all
         monies at any time paid thereon and all monies due and to become due
         thereunder, (ii) funds from time to time deposited in the Certificate
         Account and the Special Payments Account and, subject to the
         Intercreditor Agreement, any proceeds from the sale by the Trustee
         pursuant to Article VI hereof of any Equipment Note and (iii) all
         rights of the Trust and the Trustee, on behalf of the Trust, under the
         Intercreditor Agreement, the Escrow Agreement, the Note Purchase
         Agreement and the Liquidity Facilities, including, without limitation,
         all rights to receive certain payments thereunder, and all monies paid
         to the Trustee on behalf of the Trust pursuant to the Intercreditor
         Agreement or the Liquidity Facilities, provided, that rights with
         respect to the Deposits or under the Escrow Agreement, except for the
         right to direct withdrawals for the purchase of Equipment Notes to be
         held herein, will not constitute Trust Property.

                  Trustee: Means Wilmington Trust Company, or its successor in
         interest, and any successor or other trustee appointed as provided
         herein.

                  Trustee's Lien:  Has the meaning specified in Section 7.17.

                  Unindemnified Tax: Means (i) any Tax imposed on the net
         income, net worth or capital, or any franchise Tax or similar doing
         business Tax, of the Pass Through Trustee (other than any such Tax
         imposed as a result of the Company's assumption of the Equipment Notes
         pursuant to the purchase of an aircraft on an EBO Date or a Material
         Adverse Tax Event), (ii) any withholding Tax imposed by the United
         States (including, without limitation, any withholding Tax imposed by
         the United States which is imposed or increased as a result of the Pass
         Through Trustee failing to deliver to the Company any certificate or
         document necessary to establish that payments under this Agreement are
         exempt from withholding Tax), and (iii) any Avoidable Tax.

                   Section 1.02. Compliance Certificates and Opinions. Upon any
         application or request (except with respect to matters set forth in
         Article II) by the Company, any Owner Trustee or any Loan Trustee to
         the Trustee to take any action under any provision of this Agreement,
         the Company, such Owner Trustee or such Loan Trustee, as the case may
         be, shall furnish to the Trustee (i) an Officer's Certificate stating
         that, in the opinion of the signers, all conditions precedent, if any,
         provided for in this Agreement relating to the proposed action have
         been complied with and (ii) an Opinion of Counsel stating that in the
         opinion of such counsel all such conditions precedent, if any, have
         been complied with, except that in the case of any such application or
         request as to which the furnishing of such documents is specifically
         required by any provision of this Agreement relating to such particular
         application or request, no additional certificate or opinion need be
         furnished.


<PAGE>   19
                                      -14-



                  Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Agreement (other than a certificate
provided pursuant to Section 8.04(e)) shall include:

                  (1) a statement that each individual signing such certificate
         or opinion has read such covenant or condition and the definitions in
         this Agreement relating thereto;

                  (2) a brief statement as to the nature and scope of the
         examination or investigation upon which the statements or opinions
         contained in such certificate or opinion are based;

                  (3) a statement that, in the opinion of each such individual,
         he has made such examination or investigation as is necessary to enable
         him to express an informed opinion as to whether or not such covenant
         or condition has been complied with; and

                  (4) a statement as to whether, in the opinion of each such
         individual, such condition or covenant has been complied with.

                  Section 1.03. Form of Documents Delivered to Trustee. In any
case where several matters are required to be certified by, or covered by an
opinion of, any specified Person, it is not necessary that all such matters be
certified by, or covered by the opinion of, only one such Person, or that they
be so certified or covered by only one document, but one such Person may certify
or give an opinion with respect to some matters and one or more other such
Persons as to other matters and any such Person may certify or give an opinion
as to such matters in one or several documents.

                  Where any Person is required to make, give or execute two or
more applications, requests, consents, certificates, statements, opinions or
other instruments under this Agreement or, in respect of the Certificates, this
Agreement, they may, but need not, be consolidated and form one instrument.

                  Section 1.04. Directions of Certificateholders. (a) Any
direction, consent, request, demand, authorization, notice, waiver or other
action provided by this Agreement to be given or taken by Certificateholders (a
"Direction") may be embodied in and evidenced by one or more instruments of
substantially similar tenor signed by such Certificateholders in person or by an
agent or proxy duly appointed in writing; and, except as herein otherwise
expressly provided, such action shall become effective when such instrument or
instruments are delivered to the Trustee and, where it is hereby expressly
required pursuant to this Agreement, to the Company or any Loan Trustee. Proof
of execution of any such instrument or of a writing appointing any such agent or
proxy shall be sufficient for any purpose of this Agreement and conclusive in
favor of the Trustee, the Company and any Loan Trustee, if made in the manner
provided in this Section.

                  (b)     The fact and date of the execution by any Person of
any such instrument or writing may be proved by the certificate of any notary
public or other officer of any jurisdiction authorized to take acknowledgments
of deeds or administer oaths that the Person executing such instrument
acknowledged to him the execution thereof, or by an affidavit of a witness to
such execution sworn to before any such notary or such other officer and where
such execution is by 
<PAGE>   20
                                      -15-


an officer of a corporation or association or a member of a partnership, on
behalf of such corporation, association or partnership, such certificate or
affidavit shall also constitute sufficient proof of his authority. The fact and
date of the execution of any such instrument or writing, or the authority of the
Person executing the same, may also be proved in any other reasonable manner
which the Trustee deems sufficient.

                  (c)      In determining whether the Certificateholders of the
requisite Fractional Undivided Interests of Certificates Outstanding have given
any Direction under this Agreement, Certificates owned by the Company or any
Affiliate thereof shall be disregarded and deemed not to be Outstanding for
purposes of any such determination. In determining whether the Trustee shall be
protected in relying upon any such Direction, only Certificates which the
Trustee knows to be so owned shall be so disregarded. Notwithstanding the
foregoing, (i) if any such Person owns 100% of the Certificates Outstanding,
such Certificates shall not be so disregarded, and (ii) if any amount of
Certificates so owned by any such Person have been pledged in good faith, such
Certificates shall not be disregarded if the pledgee establishes to the
satisfaction of the Trustee the pledgee's right so to act with respect to such
Certificates and that the pledgee is not the Company or any Affiliate thereof.

                  (d)      For all purposes of this Agreement, all Initial
Certificates and all Exchange Certificates shall vote and take all other actions
of Certificateholders together as one series of Certificates.

                  (e)      The Company may at its option, by delivery of an
Officer's Certificate to the Trustee, set a record date to determine the
Certificateholders entitled to give any Direction. Notwithstanding Section
316(c) of the Trust Indenture Act, such record date shall be the record date
specified in such Officer's Certificate, which shall be a date not more than 30
days prior to the first solicitation of Certificateholders in connection
therewith. If such a record date is fixed, such Direction may be given before or
after such record date, but only the Certificateholders of record at the close
of business on such record date shall be deemed to be Certificateholders for the
purposes of determining whether Certificateholders of the requisite proportion
of Outstanding Certificates have authorized or agreed or consented to such
Direction, and for that purpose the Outstanding Certificates shall be computed
as of such record date; provided that no such Direction by the
Certificateholders on such record date shall be deemed effective unless it shall
become effective pursuant to the provisions of this Agreement not later than one
year after such record date.

                  (f)      Any Direction by the Holder of any Certificate shall
bind the Holder of every Certificate issued upon the transfer thereof or in
exchange therefor or in lieu thereof, whether or not notation of such Direction
is made upon such Certificate.

                  (g)      Except as otherwise provided in Section 1.04(c),
Certificates owned by or pledged to any Person shall have an equal and
proportionate benefit under the provisions of this Agreement, without
preference, priority, or distinction as among all of the Certificates.
<PAGE>   21
                                      -16-




                                   ARTICLE II

                       ORIGINAL ISSUANCE OF CERTIFICATES;
                         ACQUISITION OF EQUIPMENT NOTES

                  Section 2.01. Issuance of Certificates; Acquisition of
Equipment Notes. (a) The Trustee is hereby directed (i) to execute and deliver
the Intercreditor Agreement, the Registration Rights Agreement, the Escrow
Agreement and the Note Purchase Agreement on or prior to the Issuance Date, each
in the form delivered to the Trustee by the Company and (ii) subject to the
respective terms thereof, to perform its obligations thereunder. Upon request of
the Company and the satisfaction or waiver of the closing conditions specified
in the Certificate Purchase Agreement, the Trustee shall execute, deliver,
authenticate, issue and sell Certificates in authorized denominations equaling
in the aggregate the amount set forth, with respect to the Trust, in Schedule II
to the Certificate Purchase Agreement evidencing the entire ownership interest
in the Trust, which amount equals the maximum aggregate principal amount of
Equipment Notes which may be purchased by the Trustee pursuant to the Note
Purchase Agreement. Except as provided in Sections 3.04, 3.05, 3.06, 3.07 and
3.10 hereof, the Trustee shall not execute, authenticate or deliver Certificates
in excess of the aggregate amount specified in this paragraph.

                  (b)      On or after the Issuance Date, the Company may
deliver from time to time to the Trustee a Delivery Notice relating to one or
more Equipment Notes. After receipt of a Delivery Notice and in any case no
later than one Business Day prior to a Delivery Date as to which such Delivery
Notice relates (the "Applicable Delivery Date") (or, if the Issuance Date is an
Applicable Delivery Date, on the Issuance Date), the Trustee shall (as and when
specified in the Delivery Notice) instruct the Escrow Agent to provide a Notice
of Purchase Withdrawal to the Depositary requesting (A) the withdrawal of one or
more Deposits on the Applicable Delivery Date in accordance with and to the
extent permitted by the terms of the Escrow Agreement and the Deposit Agreement
and (B) the payment of all, or a portion, of such Deposit or Deposits in an
amount equal in the aggregate to the purchase price of such Equipment Notes to
or on behalf of the Owner Trustee or the Company, as the case may be, issuing
such Equipment Notes, all as shall be described in the Delivery Notice; provided
that, if the Issuance Date is an Applicable Delivery Date, such purchase price
shall be paid from a portion of the proceeds of the sale of the Certificates.
The Trustee shall (as and when specified in such Delivery Notice), subject to
the conditions set forth in Section 2 of the Note Purchase Agreement, enter into
and perform its obligations under the Participation Agreement specified in such
Delivery Notice (the "Applicable Participation Agreement") and cause such
certificates, documents and legal opinions relating to the Trustee to be duly
delivered as required by the Applicable Participation Agreement. If at any time
prior to the Applicable Delivery Date, the Trustee receives a notice of
postponement pursuant to Section 2(e) or 2(f) of the Note Purchase Agreement,
then the Trustee shall give the Depositary (with a copy to the Escrow Agent) a
notice of cancellation of such Notice of Purchase Withdrawal relating to such
Deposit or Deposits on such Applicable Delivery Date. Upon satisfaction of the
conditions specified in the Note Purchase Agreement and the Applicable
Participation Agreement, the Trustee shall purchase the applicable Equipment
Notes with the proceeds of the withdrawals of one or more Deposits made on the
Applicable Delivery Date in accordance with the terms of the Deposit 
<PAGE>   22
                                      -17-


Agreement and the Escrow Agreement (or, if the Issuance Date is the Applicable
Delivery Date with respect to such Applicable Participation Agreement, from a
portion of the proceeds of the sale of the Certificates). The purchase price of
such Equipment Notes shall equal the principal amount of such Equipment Notes.
Amounts withdrawn from such Deposit or Deposits in excess of the purchase price
of the Equipment Notes or to the extent not applied on the Applicable Delivery
Date to the purchase price of the Equipment Notes, shall be re-deposited by the
Trustee with the Depositary on the Applicable Delivery Date in accordance with
the terms of the Deposit Agreement.

                  Section 2.02. Withdrawal of Deposits. If any Deposits remain
outstanding on the Business Day next succeeding the Cut-Off Date, (i) (A) the
Trustee shall give the Escrow Agent notice that the Trustee's obligation to
purchase Equipment Notes under the Note Purchase Agreement has terminated and
instruct the Escrow Agent to provide a notice of Final Withdrawal to the
Depositary substantially in the form of Exhibit B to the Deposit Agreement (the
"Final Withdrawal Notice") and (B) the Trustee will make a demand upon the
Company under the Note Purchase Agreement for an amount equal to the Special
Redemption Premium, if applicable, such payment to be made on the Final
Withdrawal Date.

                  Section 2.03. Acceptance by Trustee. The Trustee, upon the
execution and delivery of this Agreement, acknowledges its acceptance of all
right, title and interest in and to the Trust Property and declares that the
Trustee holds and will hold such right, title and interest for the benefit of
all then present and future Certificateholders, upon the trusts herein set
forth. Subject to Section 7.14, the Trustee shall take all actions reasonably
necessary to effect the registration of all such Equipment Notes in the name of
the Subordination Agent. By its payment for and acceptance of each Certificate
issued to it under this Agreement, each initial Certificateholder as grantor of
the Trust thereby joins in the creation and declaration of the Trust.

                  Section 2.04. Limitation of Powers. The Trust is constituted
solely for the purpose of making the investment in the Equipment Notes, and,
except as set forth herein, the Trustee shall not be authorized or empowered to
acquire any other investments or engage in any other activities and, in
particular, the Trustee shall not be authorized or empowered to do anything that
would cause such Trust to fail to qualify as a "grantor trust" for federal
income tax purposes (including as subject to this restriction, acquiring any
Aircraft (as defined in the respective Indentures) by bidding such Equipment
Notes or otherwise, or taking any action with respect to any such Aircraft once
acquired).


                                   ARTICLE III

                                THE CERTIFICATES

                  Section 3.01. Title, Form, Denomination and Execution of
Certificates. (a) The Initial Certificates shall be known as the "6.87% Initial
Pass Through Certificates, Series 1998-1A-O" and the Exchange Certificates shall
be known as the "6.87% Exchange Pass Through Certificates, Series 1998-1A-O", in
each case, of the Trust. Each Certificate will represent a fractional undivided
interest in the Trust and shall be substantially in the form set forth as
Exhibit A hereto, with such appropriate insertions, omissions, substitutions and
other variations as are required or permitted by this Agreement and may have
such letters, numbers or other marks of 
<PAGE>   23
                                      -18-


identification and such legends or endorsements placed thereon as may be
required to comply with the rules of any securities exchange or as may,
consistently herewith, be determined by the Trustee or the officers executing
such Certificates, as evidenced by the Trustee's or officer's execution of the
Certificates (provided that such letters, numbers or other marks of
identification and such legends or endorsements are in a form acceptable to the
Company). At the Escrow Agent's request under the Escrow Agreement, the Trustee
shall affix the corresponding Escrow Receipt to each Certificate. In any event,
any transfer or exchange of any Certificate shall also effect a transfer or
exchange of the related Escrow Receipt. Prior to the Final Withdrawal Date, no
transfer or exchange of any Certificate shall be permitted unless the
Corresponding Escrow Receipt is attached thereto and also is so transferred or
exchanged. By acceptance of any Certificate to which an Escrow Receipt is
attached, each Holder of such a Certificate acknowledges and accepts the
restrictions on transfer of the Escrow Receipt set forth herein and in the
Escrow Agreement.

                  (b)      The Initial Certificates shall be issued only in
fully registered form without coupons and only in denominations of $100,000 or
integral multiples of $1,000 in excess thereof, except that one Certificate may
be issued in a different denomination. The Exchange Certificates will be issued
in denominations of $1,000 or integral multiples thereof, except that one
Certificate may be issued in a different denomination. Each Certificate shall be
dated the date of its authentication. The aggregate Fractional Undivided
Interest of Certificates shall not at any time exceed $131,670,000.

                  (c)      The Initial Certificates offered and sold in reliance
on Rule 144A shall be issued in the form of one or more Global Certificates
substantially in the form of Exhibit A hereto with such applicable legends as
are provided for in Section 3.02 (each a "Restricted Global Certificate") duly
executed and authenticated by the Trustee as hereinafter provided. Such
Restricted Global Certificates shall be in registered form and be registered in
the name of DTC and deposited with the Trustee, at its Corporate Trust Office,
as custodian for DTC. The aggregate principal amount of any Restricted Global
Certificate may from time to time be increased or decreased by adjustments made
on the records of the Trustee, as custodian for DTC for such Restricted Global
Certificate, as provided in Section 3.06 hereof, which adjustments shall be
conclusive as to the aggregate principal amount of any such Global Certificate.

                  (d)      The Initial Certificates offered and sold outside the
United States in reliance on Regulation S shall be issued in the form of one or
more global Certificates substantially in the form of Exhibit A hereto (each a
"Regulation S Global Certificate") duly executed and authenticated by the
Trustee as hereinafter provided. Such Regulation S Global Certificates shall be
in registered form and be registered in the name of DTC and deposited with the
Trustee, at its Corporate Trust Office, as custodian for DTC, for credit
initially and during the Restricted Period (hereinafter defined) to the
respective accounts of beneficial owners of such Certificates (or to such other
accounts as they may direct) at Morgan Guaranty Trust Company of New York,
Brussels office, as operator of Euroclear or Cedel. As used herein, the term
"Restricted Period", with respect to the Regulation S Global Certificates
offered and sold in reliance on Regulation S, means the period of 40 consecutive
days beginning on and including the later of (i) the day on which the
Certificates are first offered to persons other than distributors (as defined in
Regulation S) in reliance on Regulation S and (ii) the date of the closing of
the offering under the Certificate Purchase Agreement. The aggregate principal
amount of any 
<PAGE>   24
                                      -19-

Regulation S Global Certificate may from time to time be increased or decreased
by adjustments made on the records of the Trustee, as custodian for DTC for such
Global Certificate, as provided in Section 3.06 hereof, which adjustments shall
be conclusive as to the aggregate principal amount of any such Global
Certificate. The Restricted Global Certificate and Regulation S Global
Certificate are sometimes collectively referred to herein as the "Global
Certificates".

                  (e)      Initial Certificates offered and sold to any
Institutional Accredited Investor which is not a QIB in a transaction exempt
from registration under the Securities Act (and other than as described in
Section 3.01(d)) shall be issued substantially in the form of Exhibit A hereto
in definitive, fully registered form without interest coupons with such
applicable legends as are provided for in Section 3.02 (the "Restricted
Definitive Certificates") duly executed and authenticated by the Trustee as
hereinafter provided. Certificates issued pursuant to Section 3.05(b) in
exchange for interests in a Regulation S Global Certificate shall be issued in
definitive, fully registered form without interest coupons (the "Regulation S
Definitive Certificates"). The Restricted Definitive Certificates and the
Regulation S Definitive Certificates are sometimes collectively referred to
herein as the "Definitive Certificates".

                  (f)      The Exchange Certificates shall be issued in the form
of one or more global Certificates substantially in the form of Exhibit A hereto
(each, a "Global Exchange Certificate"), except that (i) the Restricted Legend
(hereinafter defined) shall be omitted and (ii) such Exchange Certificates shall
contain such appropriate insertions, omissions, substitutions and other
variations from the form set forth in Exhibit A hereto relating to the nature of
the Exchange Certificates as the Responsible Officer of the Trustee executing
such Exchange Certificates on behalf of the Trust may determine, as evidenced by
such officer's execution on behalf of the Trust of such Exchange Certificates.
Such Global Exchange Certificates shall be in registered form and be registered
in the name of DTC and deposited with the Trustee, at its Corporate Trust
Office, as custodian for DTC. The aggregate principal amount of any Global
Exchange Certificate may from time to time be increased or decreased by
adjustments made on the records of the Trustee, as custodian for DTC for such
Global Exchange Certificate, which adjustments shall be conclusive as to the
aggregate principal amount of any such Global Exchange Certificate. Subject to
clause (i) and (ii) of the first sentence of this Section 3.01(f), the terms
hereof applicable to Restricted Global Certificates and/or Global Certificates
shall apply to the Global Exchange Certificates, mutatis mutandis.

                  (g)      The Definitive Certificates shall be in registered
form and shall be typed, printed, lithographed or engraved or produced by any
combination of these methods or may be produced in any other manner, all as
determined by the officers executing such Certificates, as evidenced by their
execution of such Certificates.

                  Section 3.02. Restrictive Legends. All Initial Certificates
issued pursuant to this Agreement for resale pursuant to Rule 144A or offered
and sold to any Institutional Accredited Investor which is not a QIB (including
any Global Certificate issued upon registration of transfer, in exchange for or
in lieu of such Certificates) shall be "Restricted Certificates" and shall bear
a legend to the following effect (the "Restricted Legend") unless the Company
and the Trustee determine otherwise consistent with applicable law:
<PAGE>   25
                                      -20-


                  THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE U.S.
         SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND
         ACCORDINGLY, MAY NOT BE OFFERED OR SOLD WITHIN THE UNITED STATES OR TO,
         OR FOR THE ACCOUNT OR BENEFIT OF, ANY PERSONS EXCEPT AS SET FORTH IN
         THE FOLLOWING SENTENCE. BY ITS ACQUISITION HEREOF, THE HOLDER (1)
         REPRESENTS THAT (A) IT IS A "QUALIFIED INSTITUTIONAL BUYER" (AS DEFINED
         IN RULE 144A UNDER THE SECURITIES ACT), (B) IT IS AN INSTITUTIONAL
         "ACCREDITED INVESTOR" (AS DEFINED IN RULE 501(a)(1), (2), (3) OR (7) OF
         REGULATION D UNDER THE SECURITIES ACT) (AN "INSTITUTIONAL ACCREDITED
         INVESTOR") OR (C) IT IS NOT A U.S. PERSON AND IS ACQUIRING THIS
         CERTIFICATE IN AN OFFSHORE TRANSACTION IN COMPLIANCE WITH REGULATION S
         UNDER THE SECURITIES ACT; (2) AGREES THAT IT WILL NOT WITHIN TWO YEARS
         AFTER THE LATER OF THE ORIGINAL ISSUANCE OF THIS CERTIFICATE OR THE
         LAST DATE ON WHICH THIS CERTIFICATE WAS HELD BY AMERICA WEST AIRLINES,
         INC., THE TRUSTEE OR ANY AFFILIATE OF ANY OF SUCH PERSONS RESELL OR
         OTHERWISE TRANSFER THIS CERTIFICATE EXCEPT (A) TO AMERICA WEST
         AIRLINES, INC., (B) TO A QUALIFIED INSTITUTIONAL BUYER IN COMPLIANCE
         WITH RULE 144A UNDER THE SECURITIES ACT, (C) OUTSIDE THE UNITED STATES
         IN AN OFFSHORE TRANSACTION IN COMPLIANCE WITH RULE 904 UNDER THE
         SECURITIES ACT, (D) PURSUANT TO THE EXEMPTION FROM REGISTRATION
         PROVIDED BY RULE 144 UNDER THE SECURITIES ACT (IF AVAILABLE) OR (E)
         PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES
         ACT; AND (3) AGREES THAT IF IT SHOULD RESELL OR OTHERWISE TRANSFER THIS
         CERTIFICATE IT WILL DELIVER TO EACH PERSON TO WHOM THIS CERTIFICATE IS
         TRANSFERRED A NOTICE SUBSTANTIALLY TO THE EFFECT OF THIS LEGEND. IN
         CONNECTION WITH ANY TRANSFER OF THIS CERTIFICATE WITHIN TWO YEARS AFTER
         THE LATER OF THE ORIGINAL ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE
         ON WHICH THIS CERTIFICATE WAS HELD BY AMERICA WEST AIRLINES, INC., THE
         TRUSTEE OR ANY AFFILIATE OF ANY OF SUCH PERSONS, THE HOLDER MUST CHECK
         THE APPROPRIATE BOX SET FORTH ON THE REVERSE HEREOF RELATING TO THE
         MANNER OF SUCH TRANSFER AND SUBMIT THIS CERTIFICATE TO THE TRUSTEE. AS
         USED HEREIN, THE TERMS "OFFSHORE TRANSACTION", "UNITED STATES" AND
         "U.S. PERSON" HAVE THE MEANINGS GIVEN TO THEM BY REGULATION S UNDER THE
         SECURITIES ACT. THE PASS THROUGH TRUST AGREEMENT CONTAINS A PROVISION
         REQUIRING THE TRUSTEE TO REFUSE TO REGISTER ANY TRANSFER OF THIS
         CERTIFICATE IN VIOLATION OF THE FOREGOING RESTRICTIONS.

                  Each Global Certificate shall bear the following legend on the
         face thereof:

                  UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED
         REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION
         ("DTC"), TO THE TRUSTEE OR ITS AGENT FOR 
<PAGE>   26
                                      -21-


         REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE
         ISSUED IN EXCHANGE FOR THIS CERTIFICATE IS REGISTERED IN THE NAME OF
         CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED
         REPRESENTATIVE OF DTC (AND ANY PAYMENT HEREON IS MADE TO CEDE & CO. OR
         TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF
         DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE
         BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED OWNER
         HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

                  TRANSFERS OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO
         TRANSFERS IN WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A
         SUCCESSOR THEREOF OR SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS
         OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO TRANSFERS MADE IN
         ACCORDANCE WITH THE RESTRICTIONS SET FORTH IN SECTIONS 3.05 AND 3.06 OF
         THE PASS THROUGH TRUST AGREEMENT REFERRED TO HEREIN.

                  Section 3.03. Authentication of Certificates. (a) On the
Issuance Date, the Trustee shall duly execute, authenticate and deliver
Certificates in authorized denominations equaling in the aggregate the amount
set forth, with respect to the Trust, in Schedule II to the Certificate Purchase
Agreement, evidencing the entire ownership of the Trust, which amount equals the
maximum aggregate principal amount of Equipment Notes which may be purchased by
the Trustee pursuant to the Note Purchase Agreement.

                  (b)      No Certificate shall be entitled to any benefit under
this Agreement or be valid or obligatory for any purpose, unless there appears
on such Certificate a certificate of authentication substantially in the form
provided for herein executed by the Trustee by the manual signature of one of
its authorized signatories, and such certificate upon any Certificate shall be
conclusive evidence, and the only evidence, that such Certificate has been duly
authenticated and delivered hereunder.

                  (c)      Certificates bearing the manual or facsimile
signature of an individual who was, at the time when such signature was affixed,
authorized to sign on behalf of the Trustee shall be valid and binding
obligations of the Trust notwithstanding that such individual has ceased to be
so authorized prior to the authentication and delivery of such Certificates or
did not hold such office on the date of such Certificates.

                  Section 3.04. Transfer and Exchange. The Trustee shall cause
to be kept at the office or agency to be maintained by it in accordance with the
provisions of Section 7.12 a register (the "Register") of the Certificates in
which, subject to such reasonable regulations as it may prescribe, the Trustee
shall provide for the registration of such Certificates and of transfers and
exchanges of such Certificates as herein provided. The Trustee shall initially
be the registrar (the "Registrar") for the purpose of registering such
Certificates and transfers and exchanges of such Certificates as herein
provided. The Company, upon notice to the Trustee, may change the Registrar at
any time.
<PAGE>   27
                                      -22-


                  All Certificates issued upon any registration of transfer or
exchange of Certificates shall be valid obligations of the Trust, evidencing the
same interest therein, and entitled to the same benefits under this Trust
Agreement, as the Certificates surrendered upon such registration of transfer or
exchange.

                  A Certificateholder may transfer a Certificate, or request
that a Certificate be exchanged for Certificates in an aggregate Fractional
Undivided Interest equal to the Fractional Undivided Interest of such
Certificate surrendered for exchange of other authorized denominations, by
surrender of such Certificate to the Trustee with the form of transfer notice
thereon duly completed and executed, and otherwise complying with the terms of
this Agreement, including providing evidence of compliance with any restrictions
on transfer, in form satisfactory to the Trustee and the Registrar; provided
that no exchanges of Initial Certificates for Exchange Certificates shall occur
until an Exchange Offer Registration Statement shall have been declared
effective by the SEC (notice of which shall be provided to the Trustee by the
Company). No such transfer shall be effected until, and such transferee shall
succeed to the rights of a Certificateholder only upon, final acceptance and
registration of the transfer by the Registrar in the Register. Prior to the
registration of any transfer by a Certificateholder as provided herein, the
Trustee shall treat the person in whose name the Certificate is registered as
the owner thereof for all purposes, and the Trustee shall not be affected by
notice to the contrary. Furthermore, DTC shall, by acceptance of a Global
Certificate, agree that transfers of beneficial interests in such Global
Certificate may be effected only through a book-entry system maintained by DTC
(or its agent) and that ownership of a beneficial interest in the Certificate
shall be required to be reflected in a book-entry. When Certificates are
presented to the Registrar with a request to register the transfer thereof or to
exchange them for other authorized denominations of a Certificate in a
Fractional Undivided Interest equal to the aggregate Fractional Undivided
Interest of Certificates surrendered for exchange, the Registrar shall register
the transfer or make the exchange as requested if its requirements for such
transactions are met.

                  To permit registrations of transfers and exchanges in
accordance with the terms, conditions and restrictions hereof, the Trustee shall
execute and authenticate Certificates at the Registrar's request. No service
charge shall be made to a Certificateholder for any registration of transfer or
exchange of Certificates, but the Trustee shall require payment of a sum
sufficient to cover any tax or governmental charge that may be imposed in
connection with any transfer or exchange of Certificates. All Certificates
surrendered for registration of transfer or exchange shall be canceled and
subsequently destroyed by the Trustee.

                  Section 3.05. Book-Entry Provisions for Restricted Global
Certificates and Regulation S Global Certificates. (a) Members of, or
participants in, DTC ("Agent Members") shall have no rights under this Agreement
with respect to any Global Certificate held on their behalf by DTC, or the
Trustee as its custodian, and DTC may be treated by the Trustee and any agent of
the Trustee as the absolute owner of such Global Certificate for all purposes
whatsoever. Notwithstanding the foregoing, nothing herein shall prevent the
Trustee or any agent of the Trustee from giving effect to any written
certification, proxy or other authorization furnished by DTC or shall impair, as
between DTC and its Agent Members, the operation of customary practices
governing the exercise of the rights of a holder of any Certificate. Upon the
issuance of any Global Certificate, the Registrar or its duly appointed agent
shall record DTC as the registered holder of such Global Certificate.
<PAGE>   28
                                      -23-


                  (b)      Transfers of any Global Certificate shall be limited
to transfers of such Restricted Global Certificate or Regulation S Global
Certificate in whole, but not in part, to DTC. Beneficial interests in the
Restricted Global Certificate and any Regulation S Global Certificate may be
transferred in accordance with the rules and procedures of DTC and the
provisions of Section 3.06. Beneficial interests in a Restricted Global
Certificate or a Regulation S Global Certificate shall be delivered to all
beneficial owners thereof in the form of Restricted Definitive Certificates or
Regulation S Definitive Certificates, as the case may be, if (i) DTC notifies
the Trustee that it is unwilling or unable to continue as depositary for such
Restricted Global Certificate or Regulation S Global Certificate, as the case
may be, and a successor depositary is not appointed by the Trustee within 90
days of such notice, and (ii) after the occurrence and during the continuance of
an Event of Default, owners of beneficial interests in a Global Certificate with
Fractional Undivided Interests aggregating not less than a majority in interest
in the Trust advise the Trustee, the Company and DTC through Agent Members in
writing that the continuation of a book-entry system through DTC or its
successor is no longer in their best interests.

                  (c)      Any beneficial interest in one of the Global
Certificates that is transferred to a Person who takes delivery in the form of
an interest in another Global Certificate will, upon such transfer, cease to be
an interest in such Global Certificate and become an interest in the other
Global Certificate and, accordingly, will thereafter be subject to all transfer
restrictions, if any, and other procedures applicable to beneficial interests in
such other Global Certificate for as long as it remains such an interest.

                  (d)      In connection with the transfer of an entire
Restricted Global Certificate or an entire Regulation S Global Certificate to
the beneficial owners thereof pursuant to paragraph (b) of this Section 3.05,
such Restricted Global Certificate or Regulation S Global Certificate, as the
case may be, shall be deemed to be surrendered to the Trustee for cancellation,
and the Trustee shall execute, authenticate and deliver, to each beneficial
owner identified by DTC in exchange for its beneficial interest in such
Restricted Global Certificate or Regulation S Global Certificate, as the case
may be, an equal aggregate principal amount of Restricted Definitive
Certificates or Regulation S Definitive Certificates, as the case may be, of
authorized denominations. None of the Company, the Registrar, the Paying Agent
nor the Trustee shall be liable for any delay in delivery of such instructions
and may conclusively rely on, and shall be protected in relying on, such
registration instructions. Upon the issuance of Definitive Certificates, the
Trustee shall recognize the Person in whose name the Definitive Certificates are
registered in the Register as Certificateholders hereunder. Neither the Company
nor the Trustee shall be liable if the Trustee or the Company is unable to
locate a qualified successor clearing agency.

                  (e)      Any Definitive Certificate delivered in exchange for
an interest in the Restricted Global Certificate pursuant to paragraph (b) of
this Section 3.05 shall, except as otherwise provided by paragraph (e) of
Section 3.06, bear the Restricted Legend.

                  (f)      Prior to the expiration of the Restricted Period, any
Regulation S Definitive Certificate delivered in exchange for an interest in a
Regulation S Global Certificate pursuant to paragraph (b) of this Section shall
bear the Restricted Legend.
<PAGE>   29
                                      -24-


                  (g)      The registered holder of any Restricted Global
Certificate or Regulation S Global Certificate may grant proxies and otherwise
authorize any Person, including Agent Members and Persons that may hold
interests through Agent Members, to take any action which a Holder is entitled
to take under this Agreement or the Certificates.

                  Section 3.06. Special Transfer Provisions. Unless and until
(i) an Initial Certificate is sold under an effective Shelf Registration
Statement, or (ii) an Initial Certificate is exchanged for an Exchange
Certificate pursuant to an effective Exchange Offer Registration Statement, in
each case pursuant to the terms of the Registration Rights Agreement, the
following provisions shall apply to such Initial Certificates:

                  (a) Transfers to Non-QIB Institutional Accredited Investors.
         The following provisions shall apply with respect to the registration
         of any proposed transfer of a Certificate to any Institutional
         Accredited Investor which is neither a QIB nor a Non-U.S. Person:

                           (i) The Registrar shall register the transfer of any
                  Certificate, whether or not bearing the Restricted Legend,
                  only if (x) the requested transfer is at least two years after
                  the later of the original issue date of the Certificates and
                  the last date on which such Certificate was held by the
                  Company, the Trustee or any affiliate of any of such Persons
                  or (y) the proposed transferor is an Initial Purchaser who is
                  transferring Certificates purchased under the Certificates
                  Purchase Agreement and the proposed transferee has delivered
                  to the Registrar a letter substantially in the form of Exhibit
                  C hereto and the aggregate principal amount of the
                  Certificates being transferred is at least $100,000. Except as
                  provided in the foregoing clause (y), the Registrar shall not
                  register the transfer of any Certificate to any Institutional
                  Accredited Investor which is neither a QIB nor a Non-U.S.
                  Person.

                           (ii) If the proposed transferor is an Agent Member
                  holding a beneficial interest in a Restricted Global
                  Certificate, upon receipt by the Registrar of (x) the
                  documents, if any, required by paragraph (i) and (y)
                  instructions given in accordance with DTC's and the
                  Registrar's procedures, the Registrar shall reflect on its
                  books and records the date of the transfer and a decrease in
                  the principal amount of such Restricted Global Certificate in
                  an amount equal to the principal amount of the beneficial
                  interest in such Restricted Global Certificate to be
                  transferred, and the Trustee shall execute, authenticate and
                  deliver to the transferor or at its direction, one or more
                  Restricted Definitive Certificates of like tenor and amount.

                  (b) Transfers to QIBs. The following provisions shall apply
         with respect to the registration of any proposed transfer of an Initial
         Certificate to a QIB (excluding Non-U.S. Persons):

                           (i) If the Certificate to be transferred consists of
                  Restricted Definitive Certificates, or of an interest in any
                  Regulation S Global Certificate during the Restricted Period,
                  the Registrar shall register the transfer if such transfer is
                  being made by a proposed transferor who has checked the box
                  provided for on the form 
<PAGE>   30
                                      -25-


                  of Initial Certificate stating, or has otherwise advised the
                  Trustee and the Registrar in writing, that the sale has been
                  made in compliance with the provisions of Rule 144A to a
                  transferee who has signed the certification provided for on
                  the form of Initial Certificate stating, or has otherwise
                  advised the Trustee and the Registrar in writing, that it is
                  purchasing the Initial Certificate for its own account or an
                  account with respect to which it exercises sole investment
                  discretion and that it, or the Person on whose behalf it is
                  acting with respect to any such account, is a QIB within the
                  meaning of Rule 144A, and is aware that the sale to it is
                  being made in reliance on Rule 144A and acknowledges that it
                  has received such information regarding the Trust and/or the
                  Company as it has requested pursuant to Rule 144A or has
                  determined not to request such information and that it is
                  aware that the transferor is relying upon its foregoing
                  representations in order to claim the exemption from
                  registration provided by Rule 144A.

                           (ii) Upon receipt by the Registrar of the documents
                  required by clause (i) above and instructions given in
                  accordance with DTC's and the Registrar's procedures therefor,
                  the Registrar shall reflect on its books and records the date
                  of such transfer and an increase in the principal amount of a
                  Restricted Global Certificate in an amount equal to the
                  principal amount of the Restricted Definitive Certificates or
                  interests in such Regulation S Global Certificate, as the case
                  may be, being transferred, and the Trustee shall cancel such
                  Definitive Certificates or decrease the amount of such
                  Regulation S Global Certificate so transferred.

                  (c) Transfers of Interests in the Regulation S Global
         Certificate or Regulation S Definitive Certificates. After the
         expiration of the Restricted Period, the Registrar shall register any
         transfer of interests in any Regulation S Global Certificate or
         Regulation S Definitive Certificates without requiring any additional
         certification. Until the expiration of the Restricted Period, interests
         in the Regulation S Global Certificate may only be held through Agent
         Members acting for and on behalf of Euroclear and Cedel.

                  (d) Transfers to Non-U.S. Persons at Any Time. The following
         provisions shall apply with respect to any registration of any transfer
         of an Initial Certificate to a Non-U.S. Person:

                           (i) Prior to the expiration of the Restricted Period,
                  the Registrar shall register any proposed transfer of an
                  Initial Certificate to a Non-U.S. Person upon receipt of a
                  certificate substantially in the form set forth as Exhibit B
                  hereto from the proposed transferor.

                           (ii) After the expiration of the Restricted Period,
                  the Registrar shall register any proposed transfer to any
                  Non-U.S. Person if the Certificate to be transferred is a
                  Restricted Definitive Certificate or an interest in a
                  Restricted Global Certificate, upon receipt of a certificate
                  substantially in the form of Exhibit B from the proposed
                  transferor. The Registrar shall promptly send a copy of such
                  certificate to the Company.
<PAGE>   31
                                      -26-


                           (iii) Upon receipt by the Registrar of (x) the
                  documents, if any, required by clause (ii) and (y)
                  instructions in accordance with DTC's and the Registrar's
                  procedures, the Registrar shall reflect on its books and
                  records the date of such transfer and a decrease in the
                  principal amount of such Restricted Global Certificate in an
                  amount equal to the principal amount of the beneficial
                  interest in such Restricted Global Certificate to be
                  transferred, and, upon receipt by the Registrar of
                  instructions given in accordance with DTC's and the
                  Registrar's procedures, the Registrar shall reflect on its
                  books and records the date and an increase in the principal
                  amount of the Regulation S Global Certificate in an amount
                  equal to the principal amount of the Restricted Definitive
                  Certificate or the Restricted Global Certificate, as the case
                  may be, to be transferred, and the Trustee shall cancel the
                  Definitive Certificate, if any, so transferred or decrease the
                  amount of such Restricted Global Certificate.

                  (e) Restricted Legend. Upon the transfer, exchange or
         replacement of Certificates not bearing the Restricted Legend, the
         Registrar shall deliver Certificates that do not bear the Restricted
         Legend. Upon the transfer, exchange or replacement of Certificates
         bearing the Restricted Legend, the Registrar shall deliver only
         Certificates that bear the Restricted Legend unless either (i) the
         circumstances contemplated by paragraph (d)(ii) of this Section 3.06
         exist or (ii) there is delivered to the Registrar an Opinion of Counsel
         to the effect that neither such legend nor the related restrictions on
         transfer are required in order to maintain compliance with the
         provisions of the Securities Act.

                  (f) General. By acceptance of any Certificate bearing the
         Restricted Legend, each Holder of such a Certificate acknowledges the
         restrictions on transfer of such Certificate set forth in this
         Agreement and agrees that it will transfer such Certificate only as
         provided in this Agreement. The Registrar shall not register a transfer
         of any Certificate unless such transfer complies with the restrictions
         on transfer, if any, of such Certificate set forth in this Agreement.
         In connection with any transfer of Certificates, each Certificateholder
         agrees by its acceptance of the Certificates to furnish the Registrar
         or the Trustee such certifications, legal opinions or other information
         as either of them may reasonably require to confirm that such transfer
         is being made pursuant to an exemption from, or a transaction not
         subject to, the registration requirements of the Securities Act and in
         accordance with the terms and provisions of this Article III; provided
         that the Registrar shall not be required to determine the sufficiency
         of any such certifications, legal opinions or other information.

                  Until such time as no Certificates remain Outstanding, the
Registrar shall retain copies of all letters, notices and other written
communications received pursuant to Section 3.05 or this Section 3.06. The
Trustee, if not the Registrar at such time, shall have the right to inspect and
make copies of all such letters, notices or other written communications at any
reasonable time upon the giving of reasonable written notice to the Registrar.

                  Section 3.07. Mutilated, Destroyed, Lost or Stolen
Certificates. If (a) any mutilated Certificate is surrendered to the Registrar
or the Registrar receives evidence to its satisfaction of the destruction, loss
or theft of any Certificate and (b) there is delivered to the 
<PAGE>   32
                                      -27-


Registrar and the Trustee such security, indemnity or bond, as may be required
by them to save each of them harmless, then, in the absence of notice to the
Registrar or the Trustee that such destroyed, lost or stolen Certificate has
been acquired by a protected purchaser, and provided that the requirements of
Section 8-405 of the Uniform Commercial Code in effect in any applicable
jurisdiction are met, the Trustee shall execute, authenticate and deliver, in
exchange for or in lieu of any such mutilated, destroyed, lost or stolen
Certificate, a new Certificate or Certificates, in authorized denominations and
of like Fractional Undivided Interest and bearing a number not contemporaneously
outstanding.

                  In connection with the issuance of any new Certificate under
this Section 3.07, the Trustee may require the payment of a sum sufficient to
cover any tax or other governmental charge that may be imposed in relation
thereto and any other expenses (including the fees and expenses of the Trustee
and the Registrar) connected therewith.

                  Any duplicate Certificate issued pursuant to this Section 3.07
shall constitute conclusive evidence of the appropriate Fractional Undivided
Interest in the Trust, as if originally issued, whether or not the lost, stolen
or destroyed Certificate shall be found at any time.

                  The provisions of this Section are exclusive and shall
preclude (to the extent lawful) all other rights and remedies with respect to
the replacement or payment of mutilated, destroyed, lost or stolen Certificates.

                  Section 3.08. Persons Deemed Owners. Prior to due presentment
of a Certificate for registration of transfer, the Trustee, the Registrar and
any Paying Agent may treat the Person in whose name any Certificate is
registered (as of the day of determination) as the owner of such Certificate for
the purpose of receiving distributions pursuant to Article IV and for all other
purposes whatsoever, and none of the Trustee, the Registrar or any Paying Agent
shall be affected by any notice to the contrary.

                  Section 3.09. Cancellation. All Certificates surrendered for
payment or transfer or exchange shall, if surrendered to the Trustee or any
agent of the Trustee other than the Registrar, be delivered to the Registrar for
cancellation and shall promptly be canceled by it. No Certificates shall be
authenticated in lieu of or in exchange for any Certificates canceled as
provided in this Section, except as expressly permitted by this Agreement. All
canceled Certificates held by the Registrar shall be destroyed and a
certification of their destruction delivered to the Trustee.

                  Section 3.10. Temporary Certificates. Until definitive
Certificates are ready for delivery, the Trustee shall authenticate temporary
Certificates. Temporary Certificates shall be substantially in the form of
definitive Certificates but may have insertions, substitutions, omissions and
other variations determined to be appropriate by the officers executing the
temporary Certificates, as evidenced by their execution of such temporary
Certificates. If temporary Certificates are issued, the Trustee will cause
definitive Certificates to be prepared without unreasonable delay. After the
preparation of definitive Certificates, the temporary Certificates shall be
exchangeable for definitive Certificates upon surrender of the temporary
Certificates at the office or agency of the Trustee designated for such purpose
pursuant to Section 7.12, without charge to the Certificateholder. Upon
surrender for cancellation of any one 
<PAGE>   33
                                      -28-

or more temporary Certificates, the Trustee shall execute, authenticate and
deliver in exchange therefor a like face amount of definitive Certificates of
authorized denominations. Until so exchanged, the temporary Certificates shall
be entitled to the same benefits under this Agreement as definitive
Certificates.

                  Section 3.11. Limitation of Liability for Payments. All
payments and distributions made to Certificateholders in respect of the
Certificates shall be made only from the Trust Property and only to the extent
that the Trustee shall have sufficient income or proceeds from the Trust
Property to make such payments in accordance with the terms of Article IV of
this Agreement. Each Certificateholder, by its acceptance of a Certificate,
agrees that it will look solely to the income and proceeds from the Trust
Property for any payment or distribution due to such Certificateholder pursuant
to the terms of this Agreement and that it will not have any recourse to the
Company, the Trustee, the Loan Trustees, the Liquidity Provider, the Owner
Trustees or the Owner Participants, except as otherwise expressly provided
herein or in the Intercreditor Agreement.

                  The Company is a party to this Agreement solely for purposes
of meeting the requirements of the Trust Indenture Act, and therefore shall not
have any right, obligation or liability hereunder (except as otherwise expressly
provided herein).


                                   ARTICLE IV

                          DISTRIBUTIONS; STATEMENTS TO
                               CERTIFICATEHOLDERS

                  Section 4.01. Certificate Account and Special Payments
Account. (a) The Trustee shall establish and maintain on behalf of the
Certificateholders a Certificate Account as one or more non-interest-bearing
accounts. The Trustee shall hold the Certificate Account in trust for the
benefit of the Certificateholders, and shall make or permit withdrawals
therefrom only as provided in this Agreement. On each day when a Scheduled
Payment is made to the Trustee under the Intercreditor Agreement, the Trustee
upon receipt thereof shall immediately deposit the aggregate amount of such
Scheduled Payment in the Certificate Account.

                  (b)      The Trustee shall establish and maintain on behalf of
the Certificateholders a Special Payments Account as one or more accounts, which
shall be non-interest bearing except as provided in Section 4.04. The Trustee
shall hold the Special Payments Account in trust for the benefit of the
Certificateholders and shall make or permit withdrawals therefrom only as
provided in this Agreement. On each day when one or more Special Payments are
made to the Trustee under the Intercreditor Agreement and upon the payment of
the Special Redemption Premium to the Trustee under the Note Purchase Agreement,
the Trustee, upon receipt thereof, shall immediately deposit the aggregate
amount of such Special Payments in the Special Payments Account.

                  (c)      The Trustee shall cause the Subordination Agent to
present to the related Loan Trustee of each Equipment Note such Equipment Note
on the date of its stated final maturity or, in the case of any Equipment Note
which is to be redeemed in whole pursuant to the related Indenture, on the
applicable redemption date under such Indenture.
<PAGE>   34
                                      -29-



                  Section 4.02. Distributions from Certificate Account and
Special Payments Account. (a) On each Regular Distribution Date or as soon
thereafter as the Trustee has confirmed receipt of the payment of all or any
part of the Scheduled Payments due on such date, the Trustee shall distribute
out of the Certificate Account the entire amount deposited therein pursuant to
Section 4.01(a). There shall be so distributed to each Certificateholder of
record on the Record Date with respect to such Regular Distribution Date (other
than as provided in Section 11.01 concerning the final distribution) by check
mailed to such Certificateholder, at the address appearing in the Register, such
Certificateholder's pro rata share (based on the Fractional Undivided Interest
in the Trust held by such Certificateholder) of the total amount in the
Certificate Account, except that, with respect to Certificates registered on the
Record Date in the name of DTC, such distribution shall be made by wire transfer
in immediately available funds to the account designated by DTC.

                  (b)      On each Special Distribution Date with respect to any
Special Payment or as soon thereafter as the Trustee has confirmed receipt of
any Special Payments due on the Equipment Notes held in the related Trust or
realized upon the sale of such Equipment Notes or receipt of the Special
Redemption Premium, the Trustee shall distribute out of the Special Payments
Account the entire amount of such Special Payment deposited therein pursuant to
Section 4.01(b). There shall be so distributed to each Certificateholder of
record on the Record Date with respect to such Special Distribution Date (other
than as provided in Section 11.01 concerning the final distribution) by check
mailed to such Certificateholder, at the address appearing in the Register, such
Certificateholder's pro rata share (based on the Fractional Undivided Interest
in the Trust held by such Certificateholder) of the total amount in the Special
Payments Account on account of such Special Payment, except that, with respect
to Certificates registered on the Record Date in the name of DTC, such
distribution shall be made by wire transfer in immediately available funds to
the account designated by DTC.

                  (c)      The Trustee shall cause notice of each Special
Payment to be mailed to each Certificateholder at his address as it appears in
the Register. In the event of redemption or purchase of Equipment Notes held in
the Trust, such notice shall be mailed not less than 20 days prior to the
Special Distribution Date for the Special Payment resulting from such redemption
or purchase, which Special Distribution Date shall be the date of such
redemption or purchase. In the event of the payment of a Special Redemption
Premium by the Company to the Trustee under the Note Purchase Agreement, such
notice shall be mailed, together with the notice by the Escrow Paying Agent
under Section 2.06 of the Escrow Agreement, not less than 20 days prior to the
Special Distribution Date for such amount, which Special Distribution Date shall
be the Final Withdrawal Date. In the case of any other Special Payments, such
notice shall be mailed as soon as practicable after the Trustee has confirmed
that it has received funds for such Special Payment, stating the Special
Distribution Date for such Special Payment which shall occur not less than 20
days after the date of such notice and as soon as practicable thereafter.
Notices mailed by the Trustee shall set forth:

                  (i) the Special Distribution Date and the Record Date therefor
         (except as otherwise provided in Section 11.01),

                  (ii) the amount of the Special Payment for each $1,000 face
         amount Certificate and the amount thereof constituting principal,
         premium, if any, and interest,
<PAGE>   35
                                      -30-


                  (iii)  the reason for the Special Payment, and

                  (iv) if the Special Distribution Date is the same date as a
         Regular Distribution Date, the total amount to be received on such date
         for each $1,000 face amount Certificate.

If the amount of (i) premium, if any, payable upon the redemption or purchase of
an Equipment Note or (ii) the Special Redemption Premium, if any, has not been
calculated at the time that the Trustee mails notice of a Special Payment, it
shall be sufficient if the notice sets forth the other amounts to be distributed
and states that any premium received will also be distributed.

                  If any redemption of the Equipment Notes held in the Trust is
canceled, the Trustee, as soon as possible after learning thereof, shall cause
notice thereof to be mailed to each Certificateholder at its address as it
appears on the Register.

                  Section 4.03. Statements to Certificateholders. (a) On each
Distribution Date, the Trustee will include with each distribution to
Certificateholders of a Scheduled Payment or Special Payment, as the case may
be, a statement setting forth the information provided below (in the case of a
Special Payment, including any Special Redemption Premium, reflecting in part
the information provided by the Escrow Paying Agent under the Escrow Agreement).
Such statement shall set forth (per $1,000 face amount Certificate as to (ii),
(iii), (iv) and (v) below) the following information:

                  (i) the aggregate amount of funds distributed on such
         Distribution Date hereunder and under the Escrow Agreement, indicating
         the amount allocable to each source;

                  (ii) the amount of such distribution hereunder allocable to
         principal and the amount allocable to premium (including the Special
         Redemption Premium), if any;

                  (iii) the amount of such distribution hereunder allocable to
interest; and

                  (iv) the amount of such distribution under the Escrow
Agreement allocable to interest;

                  (v) the amount of such distribution under the Escrow Agreement
allocable to Deposits; and

                  (vi) the Pool Balance and the Pool Factor.

                  With respect to the Certificates registered in the name of
DTC, on the Record Date prior to each Distribution Date, the Trustee will
request from DTC a securities position listing setting forth the names of all
Agent Members reflected on DTC's books as holding interests in the Certificates
on such Record Date. On each Distribution Date, the Trustee will mail to each
such Agent Member the statement described above and will make available
additional copies as requested by such Agent Member for forwarding to holders of
interests in the Certificates.
<PAGE>   36
                                      -31-


                  (b)      Within a reasonable period of time after the end of
each calendar year but not later than the latest date permitted by law, the
Trustee shall furnish to each Person who at any time during such calendar year
was a Certificateholder of record a statement containing the sum of the amounts
determined pursuant to clauses (a)(i), (a)(ii), (a)(iii), (a)(iv) and (a)(v)
above for such calendar year or, in the event such Person was a
Certificateholder of record during a portion of such calendar year, for such
portion of such year, and such other items as are readily available to the
Trustee and which a Certificateholder shall reasonably request as necessary for
the purpose of such Certificateholder's preparation of its federal income tax
returns. Such statement and such other items shall be prepared on the basis of
information supplied to the Trustee by the Agent Members and shall be delivered
by the Trustee to such Agent Members to be available for forwarding by such
Agent Members to the holders of interests in the Certificates in the manner
described in Section 4.03(a).

                  (c)      Promptly following (i) the Delivery Period
Termination Date, if there has been any change in the information set forth in
clauses (x), (y) and (z) below from that set forth in page 69 of the Offering
Circular, and (ii) any early redemption or purchase of, or any default in the
payment of principal or interest in respect of, any of the Equipment Notes held
in the Trust, or any Final Withdrawal, the Trustee shall furnish to
Certificateholders of record on such date a statement setting forth (x) the
expected Pool Balances for each subsequent Regular Distribution Date following
the Delivery Period Termination Date, (y) the related Pool Factors for such
Regular Distribution Dates and (z) the expected principal distribution schedule
of the Equipment Notes, in the aggregate, held as Trust Property at the date of
such notice. With respect to the Certificates registered in the name of DTC, on
the Delivery Period Termination Date, the Trustee will request from DTC a
securities position listing setting forth the names of all Agent Members
reflected on DTC's books as holding interests in the Certificates on such date.
The Trustee will mail to each such Agent Member the statement described above
and will make available additional copies as requested by such Agent Member for
forwarding to holders of interests in the Certificates.

                  Section 4.04. Investment of Special Payment Moneys. Any money
received by the Trustee pursuant to Section 4.01(b) representing a Special
Payment which is not distributed on the date received shall, to the extent
practicable, be invested in Permitted Investments by the Trustee pending
distribution of such Special Payment pursuant to Section 4.02. Any investment
made pursuant to this Section 4.04 shall be in such Permitted Investments having
maturities not later than the date that such moneys are required to be used to
make the payment required under Section 4.02 on the applicable Special
Distribution Date and the Trustee shall hold any such Permitted Investments
until maturity. The Trustee shall have no liability with respect to any
investment made pursuant to this Section 4.04, other than by reason of the
willful misconduct or negligence of the Trustee. All income and earnings from
such investments shall be distributed on such Special Distribution Date as part
of such Special Payment.
<PAGE>   37
                                      -32-


                                    ARTICLE V

                                   THE COMPANY

                  Section 5.01. Maintenance of Corporate Existence. The Company,
at its own cost and expense, will do or cause to be done all things necessary to
preserve and keep in full force and effect its corporate existence, except as
permitted by Section 5.02.

                  Section 5.02. Consolidation, Merger, etc. The Company shall
not consolidate with or merge into any other corporation or convey, transfer or
lease substantially all of its assets as an entirety to any Person unless:

                  (a) the corporation formed by such consolidation or into which
         the Company is merged or the Person that acquires by conveyance,
         transfer or lease substantially all of the assets of the Company as an
         entirety shall be (i) organized and validly existing under the laws of
         the United States of America or any state thereof or the District of
         Columbia, (ii) a "citizen of the United States" as defined in 49 U.S.C.
         40102(a)(15), as amended, and (iii) a United States certificated air
         carrier, if and so long as such status is a condition of entitlement to
         the benefits of Section 1110 of the Bankruptcy Reform Act of 1978, as
         amended (11 U.S.C. Section 1110);

                  (b) the corporation formed by such consolidation or into which
         the Company is merged or the Person which acquires by conveyance,
         transfer or lease substantially all of the assets of the Company as an
         entirety shall execute and deliver to the Trustee a duly authorized,
         valid, binding and enforceable agreement in form and substance
         reasonably satisfactory to the Trustee containing an assumption by such
         successor corporation or Person of the due and punctual performance and
         observance of each covenant and condition of this Agreement, the Other
         Pass Through Trust Agreements and each Financing Document to be
         performed or observed by the Company; and

                  (c) the Company shall have delivered to the Trustee an
         Officer's Certificate of the Company reasonably satisfactory to the
         Trustee, stating that such consolidation, merger, conveyance, transfer
         or lease and the assumption agreement mentioned in clause (b) above
         comply with this Section 5.02 and that all conditions precedent herein
         provided for relating to such transaction have been complied with.

                  Upon any consolidation or merger, or any conveyance, transfer
or lease of substantially all of the assets of the Company as an entirety in
accordance with this Section 5.02, the successor corporation or Person formed by
such consolidation or into which the Company is merged or to which such
conveyance, transfer or lease is made shall succeed to, and be substituted for,
and may exercise every right and power of, the Company under this Agreement with
the same effect as if such successor corporation or Person had been named as the
Company herein. No such conveyance, transfer or lease of substantially all of
the assets of the Company as an entirety shall have the effect of releasing any
successor corporation or Person which shall have become such in the manner
prescribed in this Section 5.02 from its liability in respect of this Agreement
and any Financing Document to which it is a party.
<PAGE>   38
                                      -33-


                                   ARTICLE VI

                                     DEFAULT

                  Section 6.01. Events of Default. (a) Exercise of Remedies.
Upon the occurrence and during the continuation of any Indenture Default under
any Indenture, the Trustee may, to the extent it is the Controlling Party at
such time (as determined pursuant to the Intercreditor Agreement), direct the
exercise of remedies as provided in the Intercreditor Agreement.

                  (b)      Purchase Rights of Certificateholders. By acceptance
of its Certificate, each Certificateholder agrees that at any time after the
occurrence and during the continuation of a Triggering Event,

                  (i) each Class B Certificateholder shall have the right to
         purchase all, but not less than all, of the Certificates upon ten days'
         written notice to the Trustee and each other Class B Certificateholder,
         provided that (A) if prior to the end of such ten-day period any other
         Class B Certificateholder notifies such purchasing Class B
         Certificateholder that such other Class B Certificateholder wants to
         participate in such purchase, then such other Class B Certificateholder
         may join with the purchasing Class B Certificateholder to purchase all,
         but not less than all, of the Certificates pro rata based on the
         Fractional Undivided Interest in the Class B Trust held by each such
         Class B Certificateholder and (B) if prior to the end of such ten-day
         period any other Class B Certificateholder fails to notify the
         purchasing Class B Certificateholder of such other Class B
         Certificateholder's desire to participate in such a purchase, then such
         other Class B Certificateholder shall lose its right to purchase the
         Certificates pursuant to this Section 6.01(b); and

                  (ii) each Class C Certificateholder shall have the right
         (which shall not expire upon any purchase of the Certificates pursuant
         to clause (i) above) to purchase all, but not less than all, of the
         Certificates and the Class B Certificates upon ten days' written notice
         to the Trustee, the Class B Trustee and each other Class C
         Certificateholder, provided that (A) if prior to the end of such
         ten-day period any other Class C Certificateholder notifies such
         purchasing Class C Certificateholder that such other Class C
         Certificateholder wants to participate in such purchase, then such
         other Class C Certificateholder may join with the purchasing Class C
         Certificateholder to purchase all, but not less than all, of the
         Certificates and the Class B Certificates pro rata based on the
         Fractional Undivided Interest in the Class C Trust, taken as a whole,
         held by each such Class C Certificateholder and (B) if prior to the end
         of such ten-day period any other Class C Certificateholder fails to
         notify the purchasing Class C Certificateholder of such other Class C
         Certificateholder's desire to participate in such a purchase, then such
         other Class C Certificateholder shall lose its right to purchase the
         Certificates pursuant to this Section 6.01(b); and

                  (iii) each Class D Certificateholder shall have the right
         (which shall not expire upon any purchase of the Certificates pursuant
         to clause (i) or (ii) above) to purchase all, but not less than all, of
         the Certificates, the Class B Certificates and the Class C Certificates
         upon ten days' written notice to the Trustee, the Class B Trustee, the
         Class C Trustee and each other Class D Certificateholder, provided that
         (A) if prior to the end of 
<PAGE>   39
                                      -34-


         such ten-day period any other Class D Certificateholder notifies such
         purchasing Class D Certificateholder that such other Class D
         Certificateholder wants to participate in such purchase, then such
         other Class D Certificateholder may join with the purchasing Class D
         Certificateholder to purchase all, but not less than all, of the
         Certificates, the Class B Certificates and the Class C Certificates pro
         rata based on the Fractional Undivided Interest in the Class D Trust,
         taken as a whole, held by each such Class D Certificateholder and (B)
         if prior to the end of such ten day period any other Class D
         Certificateholder fails to notify the purchasing Class D
         Certificateholder of such other Class D Certificateholder's desire to
         participate in such a purchase, then such other Class D
         Certificateholder shall lose its right to purchase the Certificates
         pursuant to this Section 6.01(b).

                  The purchase price with respect to the Certificates shall be
equal to the Pool Balance of the Certificates, together with accrued and unpaid
interest thereon to the date of such purchase, without premium, but including
any other amounts then due and payable to the Certificateholders under this
Agreement, the Intercreditor Agreement, the Escrow Agreement or any Financing
Document or on or in respect of the Certificates; provided, however, that (i) if
such purchase occurs after the record date specified in Section 2.03(b) of the
Escrow Agreement relating to the distribution of unused Deposits and accrued and
unpaid interest thereunder, such purchase price shall be reduced by the
aggregate amount of unused Deposits and interest to be distributed under the
Escrow Agreement (which deducted amounts shall remain distributable to, and may
be retained by, the Certificateholder as of such Record Date) and (ii) if such
purchase occurs after a Record Date, such purchase price shall be reduced by the
amount to be distributed hereunder on the related Distribution Date (which
deducted amounts shall remain distributable to, and may be retained by, the
Certificateholder as of such Record Date); provided, further, that no such
purchase of Certificates shall be effective unless the purchaser(s) shall
certify to the Trustee that contemporaneously with such purchase, such
purchaser(s) is purchasing, pursuant to the terms of this Agreement and the
Other Pass Through Trust Agreements, the Certificates, the Class B Certificates
and the Class C Certificates which are senior to the securities held by such
purchaser(s). Each payment of the purchase price of the Certificates referred to
in the first sentence hereof shall be made to an account or accounts designated
by the Trustee and each such purchase shall be subject to the terms of this
Section 6.01(b). Each Certificateholder agrees by its acceptance of its
Certificate that it will, subject to Section 3.04 hereof, upon payment from such
Class B Certificateholder(s), Class C Certificateholder(s) or Class D
Certificateholder(s), as the case may be, of the purchase price set forth in the
first sentence of this paragraph, forthwith sell, assign, transfer and convey to
the purchaser(s) thereof (without recourse, representation or warranty of any
kind except for its own acts), all of the right, title, interest and obligation
of such Certificateholder in this Agreement, the Escrow Agreement, the Deposit
Agreement, the Intercreditor Agreement, the Liquidity Facility, the Financing
Documents and all Certificates and Escrow Receipts held by such
Certificateholder (excluding all right, title and interest under any of the
foregoing to the extent such right, title or interest is with respect to an
obligation not then due and payable as respects any action or inaction or state
of affairs occurring prior to such sale) and the purchaser shall assume all of
such Certificateholder's obligations under this Agreement, the Escrow Agreement,
the Deposit Agreement, the Intercreditor Agreement, the Liquidity Facility, the
Financing Documents and all such Certificates and Escrow Receipts. The
Certificates will be deemed to be purchased on the date payment of the purchase
price is made notwithstanding the failure of the Certificateholders to deliver
any Certificates (whether in the 
<PAGE>   40
                                      -35-


form of Definitive Certificates or beneficial interests in Global Certificates)
and, upon such a purchase, (i) the only rights of the Certificateholders will be
to deliver the Certificates to the purchaser(s) and receive the purchase price
for such Certificates and (ii) if the purchaser(s) shall so request, such
Certificateholder will comply with all the provisions of Section 3.04 hereof to
enable new Certificates to be issued to the purchaser in such denominations as
it shall request. All charges and expenses in connection with the issuance of
any such new Certificates shall be borne by the purchaser thereof.

                  As used in this Section 6.01(b), the terms "Class B
Certificate", "Class B Certificateholder", "Class B Trust", "Class B Trustee",
"Class C Certificate", "Class C Certificateholder", "Class C Trust", "Class C
Trustee", "Class D Certificate", and "Class D Trust", shall have the respective
meanings assigned to such terms in the Intercreditor Agreement.

                  Section 6.02. Incidents of Sale of Equipment Notes. Upon any
sale of all or any part of the Equipment Notes made either under the power of
sale given under this Agreement or otherwise for the enforcement of this
Agreement, the following shall be applicable:

                  (1) Certificateholders and Trustee May Purchase Equipment
         Notes. Any Certificateholder, the Trustee in its individual or any
         other capacity or any other Person may bid for and purchase any of the
         Equipment Notes, and upon compliance with the terms of sale, may hold,
         retain, possess and dispose of such Equipment Notes in their own
         absolute right without further accountability.

                  (2) Receipt of Trustee Shall Discharge Purchaser. The receipt
         of the Trustee making such sale shall be a sufficient discharge to any
         purchaser for his purchase money, and, after paying such purchase money
         and receiving such receipt, such purchaser or its personal
         representative or assigns shall not be obliged to see to the
         application of such purchase money, or be in any way answerable for any
         loss, misapplication or non-application thereof.

                  (3) Application of Moneys Received upon Sale. Any moneys
         collected by the Trustee upon any sale made either under the power of
         sale given by this Agreement or otherwise for the enforcement of this
         Agreement shall be applied as provided in Section 4.02.

                  Section 6.03. Judicial Proceedings Instituted by Trustee;
Trustee May Bring Suit. If there shall be a failure to make payment of the
principal of, premium, if any, or interest on any Equipment Note, or if there
shall be any failure to pay Rent (as defined in the relevant Lease) under any
Lease when due and payable, then the Trustee, in its own name and as trustee of
an express trust, as holder of such Equipment Notes, to the extent permitted by
and in accordance with the terms of the Intercreditor Agreement and the
Financing Documents (subject to the rights of the applicable Owner Trustee or
Owner Participant to cure any such failure to pay principal of, premium, if any,
or interest on any Equipment Note or to pay Rent under any Lease in accordance
with the applicable Indenture), shall be entitled and empowered to institute any
suits, actions or proceedings at law, in equity or otherwise, for the collection
of the sums so due and unpaid on such Equipment Notes or under such Lease and
may prosecute any such claim or 
<PAGE>   41
                                      -36-


proceeding to judgment or final decree with respect to the whole amount of any
such sums so due and unpaid.

                  Section 6.04 Control by Certificateholders. Subject to Section
6.03 and the Intercreditor Agreement, the Certificateholders holding
Certificates evidencing Fractional Undivided Interests aggregating not less than
a majority in interest in the Trust shall have the right to direct the time,
method and place of conducting any proceeding for any remedy available to the
Trustee with respect to the Trust or pursuant to the terms of the Intercreditor
Agreement, or exercising any trust or power conferred on the Trustee under this
Agreement or the Intercreditor Agreement, including any right of the Trustee as
Controlling Party under the Intercreditor Agreement or as holder of the
Equipment Notes, provided that:

                  (1) such Direction shall not be in conflict with any rule of
         law or with this Agreement and would not involve the Trustee in
         personal liability or expense,

                  (2) the Trustee shall not determine that the action so
         directed would be unjustly prejudicial to the Certificateholders not
         taking part in such Direction, and

                  (3) the Trustee may take any other action deemed proper by the
         Trustee which is not inconsistent with such Direction.

                  Section 6.05. Waiver of Past Defaults. Subject to the
Intercreditor Agreement, the Certificateholders holding Certificates evidencing
Fractional Undivided Interests aggregating not less than a majority in interest
in the Trust (i) may on behalf of all of the Certificateholders waive any past
Event of Default hereunder and its consequences or (ii) if the Trustee is the
Controlling Party, may direct the Trustee to instruct the applicable Loan
Trustee to waive any past Indenture Default under any Indenture and its
consequences, and thereby annul any Direction given by such Certificateholders
or the Trustee to such Loan Trustee with respect thereto, except a default:

                  (1) in the deposit of any Scheduled Payment or Special Payment
         under Section 4.01 or in the distribution of any payment under Section
         4.02 on the Certificates, or

                  (2) in the payment of the principal of (premium, if any) or
         interest on the Equipment Notes, or

                  (3) in respect of a covenant or provision hereof which under
         Article IX cannot be modified or amended without the consent of each
         Certificateholder holding an Outstanding Certificate affected thereby.

                  Upon any such waiver, such default shall cease to exist with
respect to the Certificates and any Event of Default arising therefrom shall be
deemed to have been cured for every purpose and any direction given by the
Trustee on behalf of the Certificateholders to the relevant Loan Trustee shall
be annulled with respect thereto; but no such waiver shall extend to any
subsequent or other default or Event of Default or impair any right consequent
thereon. Upon any such waiver, the Trustee shall vote the Equipment Notes issued
under the relevant Indenture to waive the corresponding Indenture Default.
<PAGE>   42
                                      -37-


                  Section 6.06. Right of Certificateholders to Receive Payments
Not to Be Impaired. Anything in this Agreement to the contrary notwithstanding,
including, without limitation, Section 6.07 hereof, but subject to the
Intercreditor Agreement, the right of any Certificateholder to receive
distributions of payments required pursuant to Section 4.02 hereof on the
Certificates when due, or to institute suit for the enforcement of any such
payment on or after the applicable Regular Distribution Date or Special
Distribution Date, shall not be impaired or affected without the consent of such
Certificateholder.

                  Section 6.07. Certificateholders May Not Bring Suit Except
Under Certain Conditions. A Certificateholder shall not have the right to
institute any suit, action or proceeding at law or in equity or otherwise with
respect to this Agreement, for the appointment of a receiver or for the
enforcement of any other remedy under this Agreement, unless:

                  (1) such Certificateholder previously shall have given written
         notice to the Trustee of a continuing Event of Default;

                  (2) Certificateholders holding Certificates evidencing
         Fractional Undivided Interests aggregating not less than 25% of the
         Trust shall have requested the Trustee in writing to institute such
         action, suit or proceeding and shall have offered to the Trustee
         indemnity as provided in Section 7.03(e);

                  (3) the Trustee shall have refused or neglected to institute
         such an action, suit or proceeding for 60 days after receipt of such
         notice, request and offer of indemnity; and

                  (4) no direction inconsistent with such written request shall
         have been given to the Trustee during such 60-day period by
         Certificateholders holding Certificates evidencing Fractional Undivided
         Interests aggregating not less than a majority in interest in the
         Trust.

                  It is understood and intended that no one or more of the
Certificateholders shall have any right in any manner whatsoever hereunder or
under the Certificates to (i) surrender, impair, waive, affect, disturb or
prejudice any property in the Trust Property or the lien of any Indenture on any
property subject thereto, or the rights of the Certificateholders or the holders
of the Equipment Notes, (ii) obtain or seek to obtain priority over or
preference with respect to any other such Certificateholder or (iii) enforce any
right under this Agreement, except in the manner herein provided and for the
equal, ratable and common benefit of all the Certificateholders subject to the
provisions of this Agreement.

                  Section 6.08. Remedies Cumulative. Every remedy given
hereunder to the Trustee or to any of the Certificateholders shall not be
exclusive of any other remedy or remedies, and every such remedy shall be
cumulative and in addition to every other remedy given hereunder or now or
hereafter given by statute, law, equity or otherwise.
<PAGE>   43
                                      -38-


                                   ARTICLE VII

                                   THE TRUSTEE

                  Section 7.01. Certain Duties and Responsibilities. (a) Except
during the continuance of an Event of Default, the Trustee undertakes to perform
such duties as are specifically set forth in this Agreement, and no implied
covenants or obligations shall be read into this Agreement against the Trustee.

                  (b)      In case an Event of Default has occurred and is
continuing, the Trustee shall exercise such of the rights and powers vested in
it by this Agreement, and use the same degree of care and skill in their
exercise, as a prudent man would exercise or use under the circumstances in the
conduct of its own affairs.

                  (c)      No provision of this Agreement shall be construed to
relieve the Trustee from liability for its own negligent action, its own
negligent failure to act, or its own willful misconduct, except that

                  (1) this SubSection shall not be construed to limit the effect
         of SubSection (a) of this Section; and

                  (2) the Trustee shall not be liable for any error of judgment
         made in good faith by a Responsible Officer of the Trustee, unless it
         shall be proved that the Trustee was negligent in ascertaining the
         pertinent facts.

                  (d)      Whether or not herein expressly so provided, every
provision of this Trust Agreement relating to the conduct or affecting the
liability of or affording protection to the Trustee shall be subject to the
provisions of this Section.

                  Section 7.02. Notice of Defaults. As promptly as practicable
after, and in any event within 90 days after, the occurrence of any default (as
such term is defined below) hereunder, the Trustee shall transmit by mail to the
Company, the Owner Trustees, the Owner Participants, the Loan Trustees and the
Certificateholders in accordance with Section 313(c) of the Trust Indenture Act,
notice of such default hereunder known to the Trustee, unless such default shall
have been cured or waived; provided, however, that, except in the case of a
default on the payment of the principal, premium, if any, or interest on any
Equipment Note held in the Trust, the Trustee shall be protected in withholding
such notice if and so long as the board of directors, the executive committee or
a trust committee of directors and/or Responsible Officers of the Trustee in
good faith determine that the withholding of such notice is in the interests of
the Certificateholders. For the purpose of this Section, the term "default"
means any event that is, or after notice or lapse of time or both would become,
an Event of Default.

                  Section 7.03. Certain Rights of Trustee. Subject to the
provisions of Section 315 of the Trust Indenture Act:

                  (a) the Trustee may rely and shall be protected in acting or
         refraining from acting in reliance upon any resolution, certificate,
         statement, instrument, opinion, report, notice, request, direction,
         consent, order, bond, debenture or other paper or document 
<PAGE>   44
                                      -39-


         believed by it to be genuine and to have been signed or presented by
         the proper party or parties;

                  (b) any request or direction of the Company mentioned herein
         shall be sufficiently evidenced by a written description of the subject
         matter thereof accompanied by an Officer's Certificate and an Opinion
         of Counsel as provided in Section 1.02 of this Agreement;

                  (c) whenever in the administration of this Agreement the
         Trustee shall deem it desirable that a matter be proved or established
         prior to taking, suffering or omitting any action hereunder, the
         Trustee (unless other evidence be herein specifically prescribed) may,
         in the absence of bad faith on its part, rely upon an Officer's
         Certificate of the Company, any Owner Trustee or any Loan Trustee;

                  (d) the Trustee may consult with counsel and the advice of
         such counsel or any Opinion of Counsel shall be full and complete
         authorization and protection in respect of any action taken, suffered
         or omitted by it hereunder in good faith and in reliance thereon;

                  (e) the Trustee shall be under no obligation to exercise any
         of the rights or powers vested in it by this Agreement at the Direction
         of any of the Certificateholders pursuant to this Agreement, unless
         such Certificateholders shall have offered to the Trustee reasonable
         security or indemnity against the cost, expenses and liabilities which
         might be incurred by it in compliance with such Direction;

                  (f) the Trustee shall not be bound to make any investigation
         into the facts or matters stated in any resolution, certificate,
         statement, instrument, opinion, report, notice, request, direction,
         consent, order, bond, debenture or other paper or document;

                  (g) the Trustee may execute any of the trusts or powers under
         this Agreement or perform any duties under this Agreement either
         directly or by or through agents or attorneys, and the Trustee shall
         not be responsible for any misconduct or negligence on the part of any
         agent or attorney appointed with due care by it under this Agreement;

                  (h) the Trustee shall not be liable with respect to any action
         taken or omitted to be taken by it in good faith in accordance with the
         Direction of the Certificateholders holding Certificates evidencing
         Fractional Undivided Interests aggregating not less than a majority in
         interest in the Trust relating to the time, method and place of
         conducting any proceeding for any remedy available to the Trustee, or
         exercising any trust or power conferred upon the Trustee, under this
         Agreement; and

                  (i) the Trustee shall not be required to expend or risk its
         own funds in the performance of any of its duties under this Agreement,
         or in the exercise of any of its rights or powers, if it shall have
         reasonable grounds for believing that repayment of such funds or
         adequate indemnity against such risk is not reasonably assured to it.

                  Section 7.04. Not Responsible for Recitals or Issuance of
Certificates. The recitals contained herein and in the Certificates, except the
certificates of authentication, shall not 
<PAGE>   45
                                      -40-


be taken as the statements of the Trustee, and the Trustee assumes no
responsibility for their correctness. Subject to Section 7.15, the Trustee makes
no representations as to the validity or sufficiency of this Agreement, any
Equipment Notes, the Intercreditor Agreement, the Deposit Agreement, the Escrow
Agreement, the Certificates or any other Financing Document, except that the
Trustee hereby represents and warrants that this Agreement has been, and the
Intercreditor Agreement, the Registration Rights Agreement, the Note Purchase
Agreement, the Escrow Agreement and each Certificate will be, executed,
authenticated and delivered by one of its officers who is duly authorized to
execute, authenticate and deliver such document on its behalf.

                  Section 7.05. May Hold Certificates. The Trustee, any Paying
Agent, Registrar or any of their Affiliates or any other agent in their
respective individual or any other capacity may become the owner or pledgee of
Certificates and, subject to Sections 310(b) and 311 of the Trust Indenture Act,
if applicable, may otherwise deal with the Company, the Owner Trustees or the
Loan Trustees with the same rights it would have if it were not Trustee, Paying
Agent, Registrar or such other agent.

                  Section 7.06. Money Held in Trust. Money held by the Trustee
or the Paying Agent in trust hereunder need not be segregated from other funds
except to the extent required herein or by law and neither the Trustee nor the
Paying Agent shall have any liability for interest upon any such moneys except
as provided for herein.

                  Section 7.07. Compensation and Reimbursement. The Company
         agrees:

                  (1) to pay, or cause to be paid, to the Trustee from time to
         time reasonable compensation for all services rendered by it hereunder
         as set forth in a written fee letter dated the date hereof between the
         Company and the Trustee, which letter is incorporated herein by
         reference (which compensation shall not be limited by any provision of
         law in regard to the compensation of a trustee of an express trust);

                  (2) except as otherwise expressly provided herein, to
         reimburse, or cause to be reimbursed, the Trustee upon its request for
         all reasonable out-of-pocket expenses, disbursements and advances
         incurred or made by the Trustee in accordance with any provision of
         this Agreement (including the reasonable compensation and the expenses
         and disbursements of its agents and counsel), except any such expense,
         disbursement or advance as may be attributable to its undertaking its
         normal administrative functions, or its negligence, willful misconduct
         or bad faith or as may be incurred due to the Trustee's breach of its
         representations and warranties set forth in Section 7.15; and

                  (3) to indemnify, or cause to be indemnified, the Trustee for,
         and to hold it harmless against, any loss, liability, expense or Tax
         (other than for or with respect to any Unindemnified Tax) incurred
         without negligence, willful misconduct or bad faith, on its part,
         arising out of or in connection with the acceptance or administration
         of this Trust, including the costs and expenses of defending itself
         against any claim or liability in connection with the exercise or
         performance of any of its powers or duties hereunder, except for any
         such loss, liability or expense incurred by reason of the Trustee's
         breach of its covenants hereunder or under any Financing Document to
         which it is a party or its 
<PAGE>   46
                                      -41-


         representations and warranties set forth in Section 7.15 or in any
         other Financing Document, the authorization or giving or withholding of
         any future amendments, supplements, waivers or consents with respect
         hereto or any of the Financing Documents, which amendments,
         supplements, waivers or consents are not required pursuant to the terms
         of the Financing Documents and not requested by the Company, any loss
         of tax benefits, any Unindemnified Tax, or increase in tax liability
         under any tax law whether or not the Company is required to indemnify
         thereof or pursuant to this Agreement or any costs associated with
         overhead or normal administration hereunder or any voluntary
         resignation pursuant to Section 7.09.

                  With respect to paragraph (3) above, the Trustee shall notify
the Company promptly of any claim for which it may seek indemnity and the
Company shall make payment on any such claim within 30 days of written demand
thereof (delivered together with supporting documentation). The Company shall
defend the claim and the Trustee shall cooperate in the defense. The Trustee may
have separate counsel with the consent of the Company and the Company will pay
the reasonable fees and expenses of such counsel. The Company need not pay for
any settlement made, in settlement or otherwise, without its consent.

                  With respect to any Tax other than an Unindemnified Tax, the
Trustee shall be entitled to reimbursement from, and shall have a lien prior to
the Certificates upon, the Trust Property for any such Tax incurred without
negligence, bad faith or willful misconduct, on its part, arising out of or in
connection with the acceptance or administration of such Trust (other than any
Tax attributable to the Trustee's compensation for serving as such), including
any costs and expenses incurred in contesting the imposition of any such Tax. If
the Trustee reimburses itself from the Trust Property of such Trust for any such
Tax, it will mail a brief report within 30 days setting forth the circumstances
thereof to all Certificateholders as their names and addresses appear in the
Register.

                  Section 7.08. Corporate Trustee Required; Eligibility. There
shall at all times be a Trustee hereunder which shall be eligible to act as a
trustee under Section 310(a) of the Trust Indenture Act and shall have a
combined capital and surplus of at least $75,000,000 (or a combined capital and
surplus in excess of $5,000,000 and the obligations of which, whether now in
existence or hereafter incurred, are fully and unconditionally guaranteed by a
corporation organized and doing business under the laws of the United States,
any state or territory thereof or of the District of Columbia and having a
combined capital and surplus of at least $75,000,000). If such corporation
publishes reports of conditions at least annually, pursuant to law or to the
requirements of federal, state, territorial or District of Columbia supervising
or examining authority, then for the purposes of this Section 7.08, the combined
capital and surplus of such corporation shall be deemed to be its combined
capital and surplus as set forth in its most recent report of conditions so
published.

                  In case at any time the Trustee shall cease to be eligible in
accordance with the provisions of this Section 7.08 to act as Trustee, the
Trustee shall resign immediately as Trustee in the manner and with the effect
specified in Section 7.09.
<PAGE>   47
                                      -42-


                  Section 7.09 Resignation and Removal; Appointment of
Successor. (a) No resignation or removal of the Trustee and no appointment of a
successor Trustee pursuant to this Article shall become effective until the
acceptance of appointment by the successor Trustee under Section 7.10.

                  (b)      The Trustee may resign at any time as trustee by
giving prior written notice thereof to the Company, the Authorized Agents, the
Owner Trustees and the Loan Trustees. If an instrument of acceptance by a
successor Trustee shall not have been delivered to the Company, the Authorized
Agents, the Owner Trustees, the Loan Trustees and the Trustee within 30 days
after the giving of such notice of resignation, the resigning Trustee may
petition any court of competent jurisdiction for the appointment of a successor
Trustee.

                  (c)      The Trustee may be removed at any time by Direction
of the Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not less than a majority in interest in the Trust
delivered to the Trustee and to the Company, the Owner Trustees and the Loan
Trustees.

                  (d)      If at any time:

                  (1) the Trustee shall fail to comply with Section 310 of the
         Trust Indenture Act, if applicable, after written request therefor by
         the Company or by any Certificateholder who has been a bona fide
         Certificateholder for at least six months; or

                  (2) the Trustee shall cease to be eligible under Section 7.08
         and shall fail to resign after written request therefor by the Company
         or by any such Certificateholder; or

                  (3) the Trustee shall become incapable of acting or shall be
         adjudged a bankrupt or insolvent or a receiver of the Trustee or of its
         property shall be appointed or any public officer shall take charge or
         control of the Trustee or of its property or affairs for the purpose of
         rehabilitation, conservation or liquidation;

then, in any case, (i) the Company may remove the Trustee or (ii) any
Certificateholder who has been a bona fide Certificateholder for at least six
months may, on behalf of itself and all others similarly situated, petition any
court of competent jurisdiction for the removal of the Trustee and the
appointment of a successor Trustee.

                  (e)      If a Responsible Officer of the Trustee shall obtain
actual knowledge of an Avoidable Tax which has been or is likely to be asserted,
the Trustee shall promptly notify the Company and shall, within 30 days of such
notification, resign hereunder unless within such 30-day period the Trustee
shall have received notice that the Company has agreed to pay such tax. The
Company shall promptly appoint a successor Trustee in a jurisdiction where there
are no Avoidable Taxes.

                  (f)      If the Trustee shall resign, be removed or become
incapable of acting or if a vacancy shall occur in the office of the Trustee for
any cause, the Company shall promptly appoint a successor Trustee. If, within
one year after such resignation, removal or incapability, or other occurrence of
such vacancy, a successor Trustee shall be appointed by Direction of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not 
<PAGE>   48
                                      -43-


less than a majority in interest in the Trust delivered to the Company, the
Owner Trustees, the Loan Trustees and the retiring Trustee, and the Company
approves such appointment, which approval shall not be unreasonably withheld,
then the successor Trustee so appointed shall, forthwith upon its acceptance of
such appointment, become the successor Trustee and supersede the successor
Trustee appointed as provided above. If no successor Trustee shall have been so
appointed as provided above and accepted appointment in the manner hereinafter
provided, any Certificateholder who has been a bona fide Certificateholder for
at least six months may, on behalf of himself and all others similarly situated,
petition any court of competent jurisdiction for the appointment of a successor
Trustee.

                  (g)      The successor Trustee shall give notice of the
resignation and removal of the Trustee and appointment of the successor Trustee
by mailing written notice of such event by first-class mail, postage prepaid, to
the Certificateholders as their names and addresses appear in the Register. Each
notice shall include the name of such successor Trustee and the address of its
Corporate Trust Office.

                  Section 7.10. Acceptance of Appointment by Successor. Every
successor Trustee appointed hereunder shall execute and deliver to the Company,
the Authorized Agents, the Owner Trustees and the Loan Trustees and to the
retiring Trustee an instrument accepting such appointment, and thereupon the
resignation or removal of the retiring Trustee shall become effective and such
successor Trustee, without any further act, deed or conveyance, shall become
vested with all the rights, powers, trusts and duties of the retiring Trustee;
but, on request of the Company or the successor Trustee, such retiring Trustee
shall execute and deliver an instrument transferring to such successor Trustee
all such rights, powers and trusts of the retiring Trustee and shall duly
assign, transfer and deliver to such successor Trustee all Trust Property held
by such retiring Trustee hereunder, subject nevertheless to its lien, if any,
provided for in Section 7.07. Upon request of any such successor Trustee, the
Company, the retiring Trustee and such successor Trustee shall execute and
deliver any and all instruments containing such provisions as shall be necessary
or desirable to transfer and confirm to, and for more fully and certainly
vesting in, such successor Trustee all such rights, powers and trusts.

                  No institution shall accept its appointment as a Trustee
hereunder unless at the time of such acceptance such institution shall be
qualified and eligible under this Article VII.

                  Section 7.11. Merger, Conversion, Consolidation or Succession
to Business. Any corporation into which the Trustee may be merged or converted
or with which it may be consolidated, or any corporation resulting from any
merger, conversion or consolidation to which the Trustee shall be a party, or
any corporation succeeding to all or substantially all of the corporate trust
business of the Trustee, shall be the successor of the Trustee hereunder,
provided such corporation shall be otherwise qualified and eligible under this
Article VII, without the execution or filing of any paper or any further act on
the part of any of the parties hereto. In case any Certificates shall have been
executed or authenticated, but not delivered, by the Trustee then in office, any
successor by merger, conversion or consolidation to such authenticating Trustee
may adopt such execution or authentication and deliver the Certificates so
executed or authenticated with the same effect as if such successor Trustee had
itself executed or authenticated such Certificates.
<PAGE>   49
                                      -44-


                  Section 7.12. Maintenance of Agencies. (a) There shall at all
times be maintained an office or agency in the location set forth in Section
12.03 where Certificates may be presented or surrendered for registration of
transfer or for exchange, and for payment thereof and where notices and demands
to or upon the Trustee in respect of such certificates or this Agreement may be
served; provided, however, that, if it shall be necessary that the Trustee
maintain an office or agency in another location (e.g., the Certificates shall
be represented by Definitive Certificates and shall be listed on a national
securities exchange), the Trustee will make all reasonable efforts to establish
such an office or agency. Written notice of the location of each such other
office or agency and of any change of location thereof shall be given by the
Trustee to the Company, the Owner Trustees, the Loan Trustees (in the case of
any Owner Trustee or Loan Trustee, at its address specified in the Financing
Documents or such other address as may be notified to the Trustee) and the
Certificateholders. In the event that no such office or agency shall be
maintained or no such notice of location or of change of location shall be
given, presentations and demands may be made and notices may be served at the
Corporate Trust Office of the Trustee.

                  (b)      There shall at all times be a Registrar and a Paying
Agent hereunder with respect to the Certificates. Each such Authorized Agent
shall be a bank or trust company, shall be a corporation organized and doing
business under the laws of the United States or any state, with a combined
capital and surplus of at least $75,000,000, or, if the Trustee shall be acting
as the Registrar or Paying Agent hereunder, a corporation having a combined
capital and surplus in excess of $5,000,000, the obligations of which are
guaranteed by a corporation organized and doing business under the laws of the
United States or any state, with a combined capital and surplus of at least
$75,000,000, and shall be authorized under such laws to exercise corporate trust
powers, subject to supervision by Federal or state authorities. The Trustee
shall initially be the Paying Agent and, as provided in Section 3.04, Registrar
hereunder with respect to the Certificates. Each Registrar shall furnish to the
Trustee, at stated intervals of not more than six months, and at such other
times as the Trustee may request in writing, a copy of the Register maintained
by such Registrar.

                  (c)      Any corporation into which any Authorized Agent may
be merged or converted or with which it may be consolidated, or any corporation
resulting from any merger, consolidation or conversion to which any Authorized
Agent shall be a party, or any corporation succeeding to the corporate trust
business of any Authorized Agent, shall be the successor of such Authorized
Agent hereunder, if such successor corporation is otherwise eligible under this
Section, without the execution or filing of any paper or any further act on the
part of the parties hereto or such Authorized Agent or such successor
corporation.

                  (d)      Any Authorized Agent may at any time resign by giving
written notice of resignation to the Trustee, the Company, the Owner Trustees
and the Loan Trustees. The Company may, and at the request of the Trustee shall,
at any time terminate the agency of any Authorized Agent by giving written
notice of termination to such Authorized Agent and to the Trustee. Upon the
resignation or termination of an Authorized Agent or in case at any time any
such Authorized Agent shall cease to be eligible under this Section (when, in
either case, no other Authorized Agent performing the functions of such
Authorized Agent shall have been appointed), the Company shall promptly appoint
one or more qualified successor Authorized Agents, reasonably satisfactory to
the Trustee, to perform the functions of the Authorized Agent 
<PAGE>   50
                                      -45-


which has resigned or whose agency has been terminated or who shall have ceased
to be eligible under this Section. The Company shall give written notice of any
such appointment made by it to the Trustee, the Owner Trustees and the Loan
Trustees; and in each case the Trustee shall mail notice of such appointment to
all Certificateholders as their names and addresses appear on the Register.

                  (e)      The Company agrees to pay, or cause to be paid, from
time to time to each Authorized Agent reasonable compensation for its services
and to reimburse it for its reasonable expenses as set forth in the letter
agreement referred to in Section 7.07 hereof.

                  Section 7.13. Money for Certificate Payments to Be Held in
Trust. All moneys deposited with any Paying Agent for the purpose of any payment
on Certificates shall be deposited and held in trust for the benefit of the
Certificateholders entitled to such payment, subject to the provisions of this
Section. Moneys so deposited and held in trust shall constitute a separate trust
fund for the benefit of the Certificateholders with respect to which such money
was deposited.

                  The Trustee may at any time, for the purpose of obtaining the
satisfaction and discharge of this Agreement or for any other purpose, direct
any Paying Agent to pay to the Trustee all sums held in trust by such Paying
Agent, such sums to be held by the Trustee upon the same trusts as those upon
which such sums were held by such Paying Agent; and, upon such payment by any
Paying Agent to the Trustee, such Paying Agent shall be released from all
further liability with respect to such money.

                  Section 7.14. Registration of Equipment Notes in Name of
Subordination Agent. The Trustee agrees that all Equipment Notes to be purchased
by the Trust shall be issued in the name of the Subordination Agent or its
nominee and held by the Subordination Agent in trust for the benefit of the
Certificateholders, or, if not so held, the Subordination Agent or its nominee
shall be reflected as the owner of such Equipment Notes in the register of the
issuer of such Equipment Notes.

                  Section 7.15. Representations and Warranties of Trustee. The
Trustee hereby represents and warrants that:

                  (a)      the Trustee is a Delaware banking corporation
organized and validly existing in good standing under the laws of the State of
Delaware;

                  (b)      the Trustee has full power, authority and legal right
to execute, deliver, and perform this Agreement, the Intercreditor Agreement,
the Registration Rights Agreement, the Escrow Agreement, the Note Purchase
Agreement and the Financing Documents to which it is a party and has taken all
necessary action to authorize the execution, delivery, and performance by it of
this Agreement, the Intercreditor Agreement, the Registration Rights Agreement,
the Escrow Agreement, the Note Purchase Agreement and the Financing Documents to
which it is a party;

                  (c)      the execution, delivery and performance by the
Trustee of this Agreement, the Intercreditor Agreement, the Registration Rights
Agreement, the Escrow Agreement, the Note Purchase Agreement and the Financing
Documents to which it is a party (i) will not violate 
<PAGE>   51
                                      -46-


any provision of United States federal law or the law of the state of the United
States where it is located governing the banking and trust powers of the Trustee
or any order, writ, judgment, or decree of any court, arbitrator or governmental
authority applicable to the Trustee or any of its assets, (ii) will not violate
any provision of the articles of association or by-laws of the Trustee, or (iii)
will not violate any provision of, or constitute, with or without notice or
lapse of time, a default under, or result in the creation or imposition of any
lien on any properties included in the Trust Property pursuant to the provisions
of any mortgage, indenture, contract, agreement or other undertaking to which it
is a party, which violation, default or lien could reasonably be expected to
have an adverse effect on the Trustee's performance or ability to perform its
duties hereunder or thereunder or on the transactions contemplated herein or
therein;

                  (d)      the execution, delivery and performance by the
Trustee of this Agreement, the Intercreditor Agreement, the Registration Rights
Agreement, the Escrow Agreement, the Note Purchase Agreement, and the Financing
Documents to which it is a party will not require the authorization, consent, or
approval of, the giving of notice to, the filing or registration with, or the
taking of any other action in respect of, any governmental authority or agency
of the United States or the state of the United States where it is located
regulating the banking and corporate trust activities of the Trustee; and

                  (e)      this Agreement, the Intercreditor Agreement, the
Registration Rights Agreement, the Escrow Agreement, the Note Purchase
Agreement, and the Financing Documents to which it is a party have been duly
executed and delivered by the Trustee and constitute the legal, valid, and
binding agreements of the Trustee, enforceable against it in accordance with
their respective terms, provided that enforceability may be limited by (i)
applicable bankruptcy, insolvency, reorganization, moratorium or similar laws
affecting the rights of creditors generally and (ii) general principles of
equity, regardless of whether applied in a proceeding in equity or at law.

                  Section 7.16. Withholding Taxes, Information Reporting. The
Trustee, as trustee of the grantor trust created by this Agreement, shall
exclude and withhold from each distribution of principal, premium, if any, and
interest and other amounts due under this Agreement or under the Certificates
any and all withholding taxes applicable thereto as required by law. In
addition, the Trustee shall remit such amounts as would be required by Section
1446 of the Internal Revenue Code of 1986, as amended, if the Trust were
characterized as a partnership engaged in a U.S. trade or business for U.S.
federal income tax purposes and shall withhold such amounts from amounts
distributable to or for the benefit of Certificateholders or Investors that are
not United States persons within the meaning of Section 7701(a)(30) of the
Internal Revenue Code of 1986, as amended. In this regard, the Trustee shall
cause the appropriate withholding agent to withhold with respect to such
distributions in the manner contemplated by Section 10.04 of Revenue Procedure
89-31 and Treasury Regulation 1.1445-8(b)(3) by filing a notice with the
National Association of Securities Dealers, Inc. substantially in the form of
Exhibit E hereto on or before the date 10 days prior to the Record Date. The
Trustee shall mail such notice to the National Association of Securities Dealers
no later than the date than 15 days prior to the Record Date. Investors that are
not United States Persons agree to furnish a United States taxpayer
identification number ("TIN") to the Trustee and the Trustee shall provide such
TINs to the appropriate withholding agent. The Trustee agrees to act as such
withholding agent (except to the extent contemplated above with respect to
withholding amounts 
<PAGE>   52
                                      -47-


as if the Trust were characterized as a partnership engaged in a U.S. trade or
business for U.S. federal income tax purposes) and, in connection therewith,
whenever any present or future taxes or similar charges are required to be
withheld with respect to any amounts payable in respect of the Certificates, to
withhold such amounts and timely pay the same to the appropriate authority in
the name of and on behalf of the Certificateholders, that it will file any
necessary withholding tax returns or statements when due, and that, as promptly
as possible after the payment thereof, it will deliver to each such
Certificateholder appropriate documentation showing the payment thereof,
together with such additional documentary evidence as such Certificateholders
may reasonably request from time to time. The Trustee agrees to file any other
information reports as it may be required to file under United States law. Each
Certificateholder or Investor that is not a United States person within the
meaning of Section 7701(a)(30) of the Internal Revenue Code, as amended, by its
acceptance of a Certificate or a beneficial interest therein, agrees to
indemnify and hold harmless the Trust and the Trustee from and against any
improper failure to withhold taxes from amounts payable to it or for its
benefit, other than an improper failure attributable to the gross negligence or
willful misconduct of the Trustee.

                  Section 7.17. Trustee's Liens. The Trustee in its individual
capacity agrees that it will at its own cost and expense promptly take any
action as may be necessary to duly discharge and satisfy in full any mortgage,
pledge, lien, charge, encumbrance, security interest or claim ("Trustee's
Liens") on or with respect to the Trust Property which is attributable to the
Trustee either (i) in its individual capacity and which is unrelated to the
transactions contemplated by this Agreement, the Intercreditor Agreement, the
Note Purchase Agreement or the Financing Documents, or (ii) as Trustee hereunder
or in its individual capacity and which arises out of acts or omissions on the
part of the Trustee which are not contemplated by this Agreement.

                  Section 7.18. Preferential Collection of Claims. The Trustee
shall comply with Section 311(a) of the Trust Indenture Act, excluding any
creditor relationship listed in Section 311(b) of the Trust Indenture Act. If
the Trustee shall resign or be removed as Trustee, it shall be subject to
Section 311(a) of the Trust Indenture Act to the extent provided therein.


                                  ARTICLE VIII

                CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE

                  Section 8.01. The Company to Furnish Trustee with Names and
Addresses of Certificateholders. The Company will furnish to the Trustee within
15 days after each Record Date with respect to a Scheduled Payment, and at such
other times as the Trustee may request in writing within 30 days after receipt
by the Company of any such request, a list, in such form as the Trustee may
reasonably require, of all information in the possession or control of the
Company as to the names and addresses of the Certificateholders, in each case as
of a date not more than 15 days prior to the time such list is furnished;
provided, however, that so long as the Trustee is the sole Registrar, no such
list need be furnished; and provided further, however, that no such list need be
furnished for so long as a copy of the Register is being furnished to the
Trustee pursuant to Section 7.12.
<PAGE>   53
                                      -48-


                  Section 8.02. Preservation of Information; Communications to
Certificateholders. The Trustee shall preserve, in as current a form as is
reasonably practicable, the names and addresses of Certificateholders contained
in the most recent list furnished to the Trustee as provided in Section 7.12 or
Section 8.01, as the case may be, and the names and addresses of
Certificateholders received by the Trustee in its capacity as Registrar, if so
acting. The Trustee may destroy any list furnished to it as provided in Section
7.12 or Section 8.01, as the case may be, upon receipt of a new list so
furnished.

                  Section 8.03. Reports by Trustee. Within 60 days after May 15
of each year commencing with the first full year following the issuance of the
Certificates, the Trustee shall transmit to the Certificateholders, as provided
in Section 313(c) of the Trust Indenture Act, a brief report dated as of such
May 15, if required by Section 313(a) of the Trust Indenture Act.

                  Section 8.04.     Reports by the Company.  The Company shall:

                  (a) file with the Trustee, within 30 days after the Company is
         required to file the same with the SEC, copies of the annual reports
         and of the information, documents and other reports (or copies of such
         portions of any of the foregoing as the SEC may from time to time by
         rules and regulations prescribe) which the Company is required to file
         with the SEC pursuant to Section 13 or Section 15(d) of the Securities
         Exchange Act of 1934, as amended; or, if the Company is not required to
         file information, documents or reports pursuant to either of such
         sections, then to file with the Trustee and the SEC, in accordance with
         rules and regulations prescribed by the SEC, such of the supplementary
         and periodic information, documents and reports which may be required
         pursuant to Section 13 of the Securities Exchange Act of 1934, as
         amended, in respect of a security listed and registered on a national
         securities exchange as may be prescribed in such rules and regulations;

                  (b) during any period, prior to the consummation of the
         Exchange Offer and during which the Shelf Registration Statement is not
         in effect, in which the Company is not subject to Section 13(a), 13(c)
         or 15(d) under the Securities Exchange Act of 1934, make available to
         any Holder of the Certificates in connection with any sale thereof and
         any prospective purchaser of the Certificates from such Holder, in each
         case upon request, the information specified in, and meeting the
         requirements of, Rule 144A(d)(4) under the Securities Act but only for
         so long as any of the Certificates remain outstanding and are
         "restricted securities" within the meaning of Rule 144(a)(3) under the
         Securities Act and, in any event, only until the second anniversary of
         the Issuance Date;

                  (c) file with the Trustee and the SEC, in accordance with the
         rules and regulations prescribed by the SEC, such additional
         information, documents and reports with respect to compliance by the
         Company with the conditions and covenants provided for in this
         Agreement, as may be required by such rules and regulations, including,
         in the case of annual reports, if required by such rules and
         regulations, certificates or opinions of independent public
         accountants, conforming to the requirements of Section 1.02;

                  (d) transmit to all Certificateholders, in the manner and to
         the extent provided in Section 313(c) of the Trust Indenture Act such
         summaries of any information, 
<PAGE>   54
                                      -49-


         documents and reports required to be filed by the Company pursuant to
         subsections (a) and (c) of this Section 8.04 as may be required by
         rules and regulations prescribed by the SEC; and

                  (e) furnish to the Trustee, not less often than annually, a
         brief certificate from the principal executive officer, principal
         financial officer, any Vice President (or more senior ranking officer)
         or the principal accounting officer as to his or her knowledge of the
         Company's compliance with all conditions and covenants under this
         Agreement (it being understood that for purposes of this paragraph (e),
         such compliance shall be determined without regard to any period of
         grace or requirement of notice provided under this Agreement).


                                   ARTICLE IX

                             SUPPLEMENTAL AGREEMENTS

                  Section 9.01. Supplemental Agreements Without Consent of
Certificateholders. Without the consent of the Certificateholders, the Company
may (but will not be required to), and the Trustee (subject to Section 9.03)
shall, at the Company's request, at any time and from time to time, enter into
one or more agreements supplemental hereto or, if applicable, to the
Intercreditor Agreement, the Escrow Agreement, the Note Purchase Agreement, the
Deposit Agreement, the Registration Rights Agreement or any Liquidity Facility
in form satisfactory to the Trustee, for any of the following purposes:

                  (1) to evidence the succession of another corporation to the
         Company and the assumption by any such successor of the covenants of
         the Company herein contained or of the Company's obligations under the
         Note Purchase Agreement, the Registration Rights Agreement or any
         Liquidity Facility; or

                  (2) to add to the covenants of the Company for the benefit of
         the Certificateholders, or to surrender any right or power conferred
         upon the Company in this Agreement, the Note Purchase Agreement, the
         Registration Rights Agreement or any Liquidity Facility; or

                  (3) to correct or supplement any provision in this Agreement,
         the Intercreditor Agreement, the Escrow Agreement, the Deposit
         Agreement, the Note Purchase Agreement, the Registration Rights
         Agreement or any Liquidity Facility which may be defective or
         inconsistent with any other provision herein or therein or to cure any
         ambiguity or correct any mistake or to modify any other provision with
         respect to matters or questions arising under this Agreement, the
         Escrow Agreement, the Deposit Agreement, the Note Purchase Agreement,
         the Intercreditor Agreement, the Registration Rights Agreement or any
         Liquidity Facility, provided that any such action shall not materially
         adversely affect the interests of the Certificateholders; or

                  (4) to comply with any requirement of the SEC, any applicable
         law, rules or regulations of any exchange or quotation system on which
         the Certificates are listed, any 
<PAGE>   55
                                      -50-


         regulatory body or the Registration Rights Agreement to effectuate the
         Exchange Offer; or

                  (5) to modify, eliminate or add to the provisions of this
         Agreement to such extent as shall be necessary to continue the
         qualification of this Agreement (including any supplemental agreement)
         under the Trust Indenture Act or under any similar Federal statute
         hereafter enacted, and to add to this Agreement such other provisions
         as may be expressly permitted by the Trust Indenture Act, excluding,
         however, the provisions referred to in Section 316(a)(2) of the Trust
         Indenture Act as in effect at the date as of which this instrument was
         executed or any corresponding provision in any similar Federal statute
         hereafter enacted; or

                  (6) to evidence and provide for the acceptance of appointment
         under this Agreement by the Trustee of a successor Trustee and to add
         to or change any of the provisions of this Agreement as shall be
         necessary to provide for or facilitate the administration of the Trust,
         pursuant to the requirements of Section 7.10; or

                  (7) to provide the information required under Section 7.12 and
         Section 12.03 as to the Trustee; or

                  (8) to modify or eliminate provisions relating to the transfer
         or exchange of Exchange Certificates or the Initial Certificates upon
         consummation of the Exchange Offer (as defined in the Registration
         Rights Agreement) or effectiveness of the Shelf Registration Statement
         or the Exchange Offer Registration Statement;

provided, however, that no such supplemental agreement shall adversely affect
the status of any Trust as a grantor trust under Subpart E, Part I of Subchapter
J of Chapter 1 of Subtitle A of the Internal Revenue Code of 1986, as amended,
for U.S. federal income tax purposes.

                  Section 9.02. Supplemental Agreements with Consent of
Certificateholders. With the consent of the Certificateholders holding
Certificates (including consents obtained in connection with a tender offer or
exchange offer for the Certificates) evidencing Fractional Undivided Interests
aggregating not less than a majority in interest in the Trust, by Direction of
said Certificateholders delivered to the Company and the Trustee, the Company
may (with the consent of the Owner Trustees, if any, which consent shall not be
unreasonably withheld), and the Trustee (subject to Section 9.03) shall, enter
into an agreement or agreements for the purpose of adding any provisions to or
changing in any manner or eliminating any of the provisions of this Agreement,
the Intercreditor Agreement, any Liquidity Facility, the Registration Rights
Agreement, the Escrow Agreement, the Deposit Agreement or the Note Purchase
Agreement to the extent applicable to such Certificateholders or of modifying in
any manner the rights and obligations of such Certificateholders under this
Agreement, the Intercreditor Agreement, any Liquidity Facility, the Registration
Rights Agreement, the Escrow Agreement, the Deposit Agreement or the Note
Purchase Agreement to the extent applicable to such Certificateholders or of
modifying in any manner the rights and obligations of such Certificateholders
under this Agreement, the Intercreditor Agreement, any Liquidity Facility, the
Registration Rights Agreement, the Escrow Agreement, the Deposit Agreement or
the Note Purchase Agreement; 
<PAGE>   56
                                      -51-


provided, however, that no such agreement shall, without the consent of the
Certificateholder of each Outstanding Certificate affected thereby:

                  (1) reduce in any manner the amount of, or delay the timing
         of, any receipt by the Trustee (or, with respect to the Deposits, the
         Certificateholders) of payments on the Equipment Notes held in the
         Trust or on the Deposits or distributions that are required to be made
         herein on any Certificate, or change any date of payment on any
         Certificate, or change the place of payment where, or the coin or
         currency in which, any Certificate is payable, or impair the right to
         institute suit for the enforcement of any such payment or distribution
         on or after the Regular Distribution Date or Special Distribution Date
         applicable thereto; or

                  (2) permit the disposition of any Equipment Note included in
         the Trust Property except as permitted by this Agreement, or otherwise
         deprive such Certificateholder of the benefit of the ownership of the
         Equipment Notes in the Trust; or

                  (3) reduce the specified percentage of the aggregate
         Fractional Undivided Interests of the Trust which is required for any
         such supplemental agreement, or reduce such specified percentage
         required for any waiver of compliance with certain provisions of this
         Agreement or certain defaults hereunder and their consequences provided
         for in this Agreement; or

                  (4) waive, amend or modify Section 2.4, 3.2 or 3.3 of the
         Intercreditor Agreement in a manner adverse to the Certificateholders;
         or

                  (5) modify any of the provisions of this Section 9.02 or
         Section 6.05, except to increase any such percentage or to provide that
         certain other provisions of this Agreement cannot be modified or waived
         without the consent of the Certificateholder of each Certificate
         affected thereby; or

                  (6) adversely affect the status of any Trust as a grantor
         trust under Subpart E, Part I of Subchapter J of Chapter 1 of Subtitle
         A of the Internal Revenue Code of 1986, as amended, for U.S.
         federal income tax purposes.

                  It shall not be necessary for any Direction of
Certificateholders under this Section to approve the particular form of any
proposed supplemental agreement, but it shall be sufficient if such Direction
shall approve the substance thereof.

                  Section 9.03. Documents Affecting Immunity or Indemnity.
Except for the performance of its covenants herein, if in the opinion of the
Trustee any document required to be executed by it pursuant to the terms of
Section 9.01 or 9.02 affects adversely any interest, right, duty, immunity or
indemnity in favor of the Trustee under this Agreement, the Trustee may in its
discretion decline to execute such document.

                  Section 9.04. Execution of Supplemental Agreements. In
executing, or accepting the additional trusts created by, any agreement
permitted by this Article or the modifications thereby of the trusts created by
this Agreement, the Trustee shall be entitled to 
<PAGE>   57
                                      -52-


receive, and shall be fully protected in relying upon, an Opinion of Counsel
stating that the execution of such supplemental agreement is authorized or
permitted by this Agreement.

                  Section 9.05. Effect of Supplemental Agreements. Upon the
execution of any agreement supplemental to this Agreement under this Article,
this Agreement shall be modified in accordance therewith, and such supplemental
agreement shall form a part of this Agreement for all purposes; and every Holder
of a Certificate theretofore or thereafter authenticated and delivered hereunder
shall be bound thereby.

                  Section 9.06. Conformity with Trust Indenture Act. Every
supplemental agreement executed pursuant to this Article shall conform to the
requirements of the Trust Indenture Act as then in effect.

                  Section 9.07. Reference in Certificates to Supplemental
Agreements. Certificates authenticated and delivered after the execution of any
supplemental agreement pursuant to this Article may bear a notation in form
approved by the Trustee as to any matter provided for in such supplemental
agreement; and, in such case, suitable notation may be made upon Outstanding
Certificates after proper presentation and demand.


                                    ARTICLE X

                AMENDMENTS TO INDENTURES AND FINANCING DOCUMENTS

                  Section 10.01. Amendments and Supplements to Indentures and
Financing Documents. In the event that the Trustee, as holder (or beneficial
owner through the Subordination Agent) of any Equipment Note in trust for the
benefit of the Certificateholders or as Controlling Party under the
Intercreditor Agreement, receives (directly or indirectly through the
Subordination Agent) a request for a consent to any amendment, modification,
waiver or supplement under any Indenture, any other Financing Document, any
Equipment Note or any other related document, the Trustee shall forthwith send a
notice of such proposed amendment, modification, waiver or supplement to each
Certificateholder registered on the Register as of the date of such notice. The
Trustee shall request from the Certificateholders a Direction as to (a) whether
or not to take or refrain from taking (or direct the Subordination Agent to take
or refrain from taking) any action which a holder of such Equipment Note has the
option to direct, (b) whether or not to give or execute (or direct the
Subordination Agent to give or execute) any waivers, consents, amendments,
modifications or supplements as a holder of such Equipment Note or a Controlling
Party and (c) how to vote (or direct the Subordination Agent to vote) any
Equipment Note if a vote has been called for with respect thereto. Provided such
a request for Certificateholder Direction shall have been made, in directing any
action or casting any vote or giving any consent as the holder of any Equipment
Note (or in directing the Subordination Agent in any of the foregoing), (i)
other than as Controlling Party, the Trustee shall vote for or give consent to
any such action with respect to such Equipment Note in the same proportion as
that of (A) the aggregate face amounts of all Certificates actually voted in
favor of or for giving consent to such action by such Direction of
Certificateholders to (B) the aggregate face amount of all Outstanding
Certificates and (ii) as Controlling Party, the Trustee shall vote as directed
in such Certificateholder Direction by the Certificateholders evidencing a
Fractional Undivided Interest aggregating not less than a majority in interest
in the Trust. For purposes of the immediately 
<PAGE>   58
                                      -53-


preceding sentence, a Certificate shall have been "actually voted" if the Holder
of such Certificate has delivered to the Trustee an instrument evidencing such
Holder's consent to such Direction prior to two Business Days before the Trustee
directs such action or casts such vote or gives such consent. Notwithstanding
the foregoing, but subject to Section 6.04 and the Intercreditor Agreement, the
Trustee may, in its own discretion and at its own direction, consent and notify
the relevant Loan Trustee of such consent (or direct the Subordination Agent to
consent and notify the Loan Trustee of such consent) to any amendment,
modification, waiver or supplement under the relevant Indenture, any other
Financing Document, any Equipment Note or any other related document, if an
Event of Default hereunder shall have occurred and be continuing, or if such
amendment, modification, waiver or supplement will not materially adversely
affect the interests of the Certificateholders.


                                   ARTICLE XI

                              TERMINATION OF TRUST

                  Section 11.01. Termination of the Trust. The respective
obligations and responsibilities of the Company and the Trustee with respect to
the Trust shall terminate upon the earlier of (A) the completion of the
assignment, transfer and discharge described in the first sentence of the
immediately following paragraph and (B) distribution to all Holders of
Certificates and the Trustee of all amounts required to be distributed to them
pursuant to this Agreement and the disposition of all property held as part of
the Trust Property; provided, however, that in no event shall the Trust continue
beyond one hundred ten (110) years following the date of the earliest execution
of this Trust Agreement.

                  Upon the earlier of (i) the first Business Day after November
30, 1999, or, if later, the fifth Business Day following the Delivery Period
Termination Date and (ii) the fifth Business Day following the date on which a
Triggering Event occurs (such date, the "Transfer Date"), or, if later the date
on which all of the conditions set forth in the immediately following sentence
have been satisfied, the Trustee is hereby directed (subject only to the
immediately following sentence) to, and the Company shall direct the institution
that will serve as the Related Trustee under the Related Pass Through Trust
Agreement to, execute and deliver the Assignment and Assumption Agreement,
pursuant to which the Trustee shall assign, transfer and deliver all of the
Trustee's right, title and interest to the Trust Property to the Related Trustee
under the Related Pass Through Trust Agreement. The Trustee and the Related
Trustee shall execute and deliver the Assignment and Assumption Agreement upon
the satisfaction of the following conditions:

                  (i) The Trustee, the Related Trustee and each of the Rating
         Agencies then rating the Certificates shall have received an Officer's
         Certificate and an Opinion of Counsel dated the date of the Assignment
         and Assumption Agreement and each satisfying the requirements of
         Section 1.02, which Opinion of Counsel shall be substantially to the
         effect set forth below and may be relied upon by the Beneficiaries (as
         defined in the Assignment and Assumption Agreement):

                  (a)      upon the execution and delivery thereof by the
                           parties thereto in accordance with the terms of this
                           Agreement and the Related Pass Through Trust
                           Agreement, the Assignment and Assumption Agreement
<PAGE>   59
                                      -54-


                           will constitute the valid and binding obligation of
                           each of the parties thereto enforceable against each
                           such party in accordance with its terms;

                  (b)      upon the execution and delivery of the Assignment and
                           Assumption Agreement in accordance with the terms of
                           this Agreement and the Related Pass Through Trust
                           Agreement, each of the Certificates then Outstanding
                           will be entitled to the benefits of the Related Pass
                           Through Trust Agreement;

                  (c)      the Related Trust is not required to be registered as
                           an investment company under the Investment Company
                           Act of 1940, as amended;

                  (d)      the Related Pass Through Trust Agreement constitutes
                           the valid and binding obligation of the Company
                           enforceable against the Company in accordance with
                           its terms; and

                  (e)      neither the execution and delivery of the Assignment
                           and Assumption Agreement in accordance with the terms
                           of this Agreement and the Related Pass Through Trust
                           Agreement, nor the consummation by the parties
                           thereto of the transactions contemplated to be
                           consummated thereunder on the date thereof, will
                           violate any law or governmental rule or regulation of
                           the State of New York or the United States of America
                           known to such counsel to be applicable to the
                           transactions contemplated by the Assignment and
                           Assumption Agreement.

                  (ii) The Trustee and the Company shall have received (x) a
         copy of the articles of incorporation and bylaws of the Related Trustee
         certified as of the Transfer Date by the Secretary or Assistant
         Secretary of such institution and (y) a copy of the filing (including
         all attachments thereto) made by the institution serving as the Related
         Trustee with the Office of the Superintendent, State of New York
         Banking Department for the qualification of the Related Trustee under
         Section 131(3) of the New York Banking Law.

Upon the execution of the Assignment and Assumption Agreement by the parties
thereto, the Trust shall be terminated, the Certificateholders shall receive
beneficial interests in the Related Trust in exchange for their interests in the
Trust equal to their respective beneficial interests in the Trust, and the
Outstanding Certificates representing Fractional Undivided Interests in the
Trust shall be deemed for all purposes of this Agreement and the Related Pass
Through Trust Agreement, without further signature or action of any party or
Certificateholder, to be certificates representing the same fractional undivided
interests in the Related Trust and its trust property. By acceptance of its
Certificate, each Certificateholder consents to such assignment, transfer and
delivery of the Trust Property to the trustee of the Related Trust upon the
execution and delivery of the Assignment and Assumption Agreement.

                  In connection with the occurrence of the event set forth in
clause (B) above, notice of such termination, specifying the Distribution Date
upon which the Certificateholders may surrender their Certificates to the
Trustee for payment of the final distribution and cancellation, shall be mailed
promptly by the Trustee to Certificateholders not earlier than the 
<PAGE>   60
                                      -55-


60th day and not later than the 20th day next preceding such final Distribution
Date specifying (A) the Distribution Date upon which the proposed final payment
of the Certificates will be made upon presentation and surrender of Certificates
at the office or agency of the Trustee therein specified, (B) the amount of any
such proposed final payment, and (C) that the Record Date otherwise applicable
to such Distribution Date is not applicable, payments being made only upon
presentation and surrender of the Certificates at the office or agency of the
Trustee therein specified. The Trustee shall give such notice to the Registrar
at the time such notice is given to Certificateholders. Upon presentation and
surrender of the Certificates in accordance with such notice, the Trustee shall
cause to be distributed to Certificateholders such final payments.

                  In the event that all of the Certificateholders shall not
surrender their Certificates for cancellation within six months after the date
specified in the above-mentioned written notice, the Trustee shall give a second
written notice to the remaining Certificateholders to surrender their
Certificates for cancellation and receive the final distribution with respect
thereto. No additional interest shall accrue on the Certificates after the
Distribution Date specified in the first written notice. In the event that any
money held by the Trustee for the payment of distributions on the Certificates
shall remain unclaimed for two years (or such lesser time as the Trustee shall
be satisfied, after sixty days' notice from the Company, is one month prior to
the escheat period provided under applicable law) after the final distribution
date with respect thereto, the Trustee shall pay to each Loan Trustee the
appropriate amount of money relating to such Loan Trustee and shall give written
notice thereof to the related Owner Trustees, the Owner Participants and the
Company.


                                   ARTICLE XII

                            MISCELLANEOUS PROVISIONS

                  Section 12.01. Limitation on Rights of Certificateholders. The
death or incapacity of any Certificateholder shall not operate to terminate this
Agreement or the Trust, nor entitle such Certificateholder's legal
representatives or heirs to claim an accounting or to take any action or
commence any proceeding in any court for a partition or winding up of the Trust,
nor otherwise affect the rights, obligations, and liabilities of the parties
hereto or any of them.

                  Section 12.02. Certificates Nonassessable and Fully Paid.
Except as set forth in the last sentence of this Section 12.02,
Certificateholders shall not be personally liable for obligations of the Trust,
the Fractional Undivided Interests represented by the Certificates shall be
nonassessable for any losses or expenses of the Trust or for any reason
whatsoever, and Certificates, upon authentication thereof by the Trustee
pursuant to Section 3.03, are and shall be deemed fully paid. No
Certificateholder shall have any right (except as expressly provided herein) to
vote or in any manner otherwise control the operation and management of the
Trust Property, the Trust, or the obligations of the parties hereto, nor shall
anything set forth herein, or contained in the terms of the Certificates, be
construed so as to constitute the Certificateholders from time to time as
partners or members of an association. Neither the existence of the Trust nor
any provision herein is intended to or shall limit the liability the
Certificateholders would otherwise incur if the Certificateholders owned Trust
Property as co-owners, or incurred any obligations of the Trust, directly rather
than through the Trust.
<PAGE>   61
                                      -56-


                  Section 12.03. Notices. (a) Unless otherwise specifically
provided herein, all notices required under the terms and provisions of this
Agreement shall be in English and in writing, and any such notice may be given
by United States mail, courier service or telecopy, and any such notice shall be
effective when received or, if made, given, furnished or filed by facsimile or
telecommunication transmission, when received unless received outside of
business hours, in which case on the next open of business on a Business Day,

                  if to the Company, to:

                           America West Airlines, Inc.
                           4000 East Sky Harbor Boulevard
                           Phoenix, Arizona  85043

                           Attention:  Vice President-
                                       Treasurer
                           Facsimile:  (602) 693-5886


                  if to the Trustee, to:

                           Wilmington Trust Company
                           Rodney Square North
                           1100 North Market Street
                           Wilmington, Delaware  19890-0001

                           Attention:  Corporate Trust Department
                           Facsimile:  (302) 651-8882
                           Telephone:   (302) 651-8584

                  (b)      The Company or the Trustee, by notice to the other,
may designate additional or different addresses for subsequent notices or
communications.

                  (c)      Any notice or communication to Certificateholders
shall be mailed by first-class mail to the addresses for Certificateholders
shown on the Register kept by the Registrar. Failure so to mail a notice or
communication or any defect in such notice or communication shall not affect its
sufficiency with respect to other Certificateholders.

                  (d)      If a notice or communication is mailed in the manner
provided above within the time prescribed, it is conclusively presumed to have
been duly given, whether or not the addressee receives it.

                  (e)      If the Company mails a notice or communication to the
Certificateholders, it shall mail a copy to the Trustee and to the Paying Agent
at the same time.

                  (f)      Notwithstanding the foregoing, all communications or
notices to the Trustee shall be deemed to be given only when received by a
Responsible Officer of the Trustee.
<PAGE>   62
                                      -57-


                  (g)      The Trustee shall promptly furnish the Company with a
copy of any demand, notice or written communication received by the Trustee
hereunder from any Certificateholder, Owner Trustee or Loan Trustee.

                  Section 12.04. Governing Law. THIS AGREEMENT HAS BEEN
DELIVERED IN THE STATE OF DELAWARE AND THIS AGREEMENT AND THE CERTIFICATES SHALL
BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF
DELAWARE AND THE OBLIGATIONS, RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER SHALL
BE DETERMINED IN ACCORDANCE WITH SUCH LAWS.

                  Section 12.05. Severability of Provisions. If any one or more
of the covenants, agreements, provisions or terms of this Agreement shall be for
any reason whatsoever held invalid, then such covenants, agreements, provisions,
or terms shall be deemed severable from the remaining covenants, agreements,
provisions or terms of this Agreement and shall in no way affect the validity or
enforceability of the other provisions of this Agreement or the Trust, or of the
Certificates or the rights of the Certificateholders thereof.

                  Section 12.06. Trust Indenture Act Controls. Upon the
occurrence of any Registration Event, this Agreement shall become subject to the
provisions of the Trust Indenture Act and shall, to the extent applicable, be
governed by such provisions. From and after any Registration Event, if any
provision of this Agreement limits, qualifies or conflicts with another
provision which is required to be included in this Agreement by the Trust
Indenture Act, the required provision shall control.

                  Section 12.07. Effect of Headings and Table of Contents. The
Article and Section headings herein and the Table of Contents are for
convenience only and shall not affect the construction hereof.

                  Section 12.08. Successors and Assigns. All covenants,
agreements, representations and warranties in this Agreement by the Trustee and
the Company shall bind and, to the extent permitted hereby, shall inure to the
benefit of and be enforceable by their respective successors and assigns,
whether so expressed or not.

                  Section 12.09. Benefits of Agreement. Nothing in this
Agreement or in the Certificates, express or implied, shall give to any Person,
other than the parties hereto and their successors hereunder, and the
Certificateholders, any benefit or any legal or equitable right, remedy or claim
under this Agreement.

                  Section 12.10. Legal Holidays. In any case where any Regular
Distribution Date or Special Distribution Date relating to any Certificate shall
not be a Business Day, then (notwithstanding any other provision of this
Agreement) payment need not be made on such date, but may be made on the next
succeeding Business Day with the same force and effect as if made on such
Regular Distribution Date or Special Distribution Date, and no interest shall
accrue during the intervening period.

                  Section 12.11. Counterparts. For the purpose of facilitating
the execution of this Agreement and for other purposes, this Agreement may be
executed simultaneously in any 
<PAGE>   63
                                      -58-


number of counterparts, each of which counterparts shall be deemed to be an
original, and all of which counterparts shall constitute but one and the same
instrument.

                  Section 12.12. Intention of Parties. The parties hereto intend
that the Trust be classified for U.S. federal income tax purposes as a grantor
trust under Subpart E, Part I of Subchapter J of the Internal Revenue Code of
1986, as amended, and not as a trust or association taxable as a corporation or
as a partnership. Each Certificateholder and Investor, by its acceptance of its
Certificate or a beneficial interest therein, agrees to treat the Trust as a
grantor trust for all U.S. federal, state and local income tax purposes. The
powers granted and obligations undertaken pursuant to this Agreement shall be so
construed so as to further such intent.
<PAGE>   64
                                      -59-



                  IN WITNESS WHEREOF, the parties have caused this Agreement to
be duly executed by their respective officers thereunto duly authorized as of
the day and year first written above.


                                        AMERICA WEST AIRLINES, INC.


                                        By: /s/ W. Douglas Parker
                                           -------------------------------------
                                            Name: W. Douglas Parker
                                            Title: Sr. Vice President & CFO


                                        WILMINGTON TRUST COMPANY,
                                            as Trustee


                                        By: /s/ Jill K. Morrison
                                           -------------------------------------
                                            Name: Jill K. Morrison
                                            Title: Administrative Account
                                                   Manager
<PAGE>   65
                                                                       EXHIBIT A

                               FORM OF CERTIFICATE

REGISTERED

No._________

         [THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE U.S. SECURITIES ACT
         OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND ACCORDINGLY, MAY NOT BE
         OFFERED OR SOLD WITHIN THE UNITED STATES OR TO, OR FOR THE ACCOUNT OR
         BENEFIT OF, ANY PERSONS EXCEPT AS SET FORTH IN THE FOLLOWING SENTENCE.
         BY ITS ACQUISITION HEREOF, THE HOLDER (1) REPRESENTS THAT (A) IT IS A
         "QUALIFIED INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A UNDER THE
         SECURITIES ACT), (B) IT IS AN INSTITUTIONAL "ACCREDITED INVESTOR" (AS
         DEFINED IN RULE 501(a)(1), (2), (3) OR (7) OF REGULATION D UNDER THE
         SECURITIES ACT) (AN "INSTITUTIONAL ACCREDITED INVESTOR") OR (C) IT IS
         NOT A U.S. PERSON AND IS ACQUIRING THIS CERTIFICATE IN AN OFFSHORE
         TRANSACTION IN COMPLIANCE WITH REGULATION S UNDER THE SECURITIES ACT;
         (2) AGREES THAT IT WILL NOT WITHIN TWO YEARS AFTER THE LATER OF THE
         ORIGINAL ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS
         CERTIFICATE WAS HELD BY AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY
         AFFILIATE OF ANY OF SUCH PERSONS RESELL OR OTHERWISE TRANSFER THIS
         CERTIFICATE EXCEPT (A) AMERICA WEST AIRLINES, INC., (B) TO A QUALIFIED
         INSTITUTIONAL BUYER IN COMPLIANCE WITH RULE 144A UNDER THE SECURITIES
         ACT, (C) OUTSIDE THE UNITED STATES IN AN OFFSHORE TRANSACTION IN
         COMPLIANCE WITH RULE 904 UNDER THE SECURITIES ACT, (D) PURSUANT TO THE
         EXEMPTION FROM REGISTRATION PROVIDED BY RULE 144 UNDER THE SECURITIES
         ACT (IF AVAILABLE) OR (E) PURSUANT TO AN EFFECTIVE REGISTRATION
         STATEMENT UNDER THE SECURITIES ACT; AND (3) AGREES THAT IF IT SHOULD
         RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE IT WILL DELIVER TO EACH
         PERSON TO WHOM THIS CERTIFICATE IS TRANSFERRED A NOTICE SUBSTANTIALLY
         TO THE EFFECT OF THIS LEGEND. IN CONNECTION WITH ANY TRANSFER OF THIS
         CERTIFICATE WITHIN TWO YEARS AFTER THE LATER OF THE ORIGINAL ISSUANCE
         OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS CERTIFICATE WAS HELD
         BY AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY AFFILIATE OF ANY OF
         SUCH PERSONS, THE HOLDER MUST CHECK THE APPROPRIATE BOX SET FORTH ON
         THE REVERSE HEREOF RELATING TO THE MANNER OF SUCH TRANSFER AND SUBMIT
         THIS CERTIFICATE TO THE TRUSTEE. AS USED HEREIN, THE TERMS "OFFSHORE
         TRANSACTION", "UNITED STATES" AND "U.S. PERSON" HAVE THE MEANINGS GIVEN
         TO THEM BY REGULATION S UNDER THE SECURITIES ACT. THE PASS THROUGH
         TRUST AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO REFUSE TO
         REGISTER ANY 
<PAGE>   66
                                      A-2



         TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE FOREGOING
         RESTRICTIONS.]*

         [UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE
         OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE
         TRUSTEE OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT,
         AND ANY CERTIFICATE ISSUED IN EXCHANGE FOR THIS CERTIFICATE IS
         REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS
         REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT
         HEREON IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY
         AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE
         HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH
         AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

         TRANSFERS OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO TRANSFERS IN
         WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A SUCCESSOR THEREOF OR
         SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL
         CERTIFICATE SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE
         RESTRICTIONS SET FORTH IN SECTIONS 3.05 AND 3.06 OF THE PASS THROUGH
         TRUST AGREEMENT REFERRED TO HEREIN.]**

         *        Not to be included on the face of the Regulation S Global
                  Certificate.

         **       To be included on the face of each Global Certificate.
<PAGE>   67
                                      A-3



                             [GLOBAL CERTIFICATE]*

           AMERICA WEST AIRLINES PASS THROUGH TRUST, SERIES 1998-1A-O

                6.87% America West Airlines [Initial] [Exchange]
                            Pass Through Certificate,
                                Series 1998-1A-O

                   Final Legal Distribution Date: July 2, 2018

evidencing a fractional undivided interest in a trust, the property of which
includes certain equipment notes each secured by an Aircraft leased to or owned
by America West Airlines, Inc.

                  $__________ Fractional Undivided Interest representing 
                  0.0007594744% of the Trust per $1,000 face amount

                  THIS CERTIFIES THAT _______________, for value received, is
the registered owner of a $________ (__________dollars) Fractional Undivided
Interest in the America West Airlines Pass Through Trust, Series 1998-1A-O (the
"Trust") created pursuant to a Pass Through Trust Agreement, dated as of October
6, 1998 (the "Agreement"), between Wilmington Trust Company (the "Trustee") and
America West Airlines, Inc., a corporation incorporated under Delaware law (the
"Company"), a summary of certain of the pertinent provisions of which is set
forth below. To the extent not otherwise defined herein, the capitalized terms
used herein have the meanings assigned to them in the Agreement. This
Certificate is one of the duly authorized Certificates designated as "6.87%
America West Airlines [Initial] [Exchange] Pass Through Certificates, Series
1998-1A-O" (herein called the "Certificates"). This Certificate is issued under
and is subject to the terms, provisions, and conditions of the Agreement. By
virtue of its acceptance hereof the Certificateholder of this Certificate
assents to and agrees to be bound by the provisions of the Agreement and the
Intercreditor Agreement. The property of the Trust includes an interest in
certain Equipment Notes and all rights of the Trust to receive payments under
the Intercreditor Agreement and any Liquidity Facility (the "Trust Property").
Each issue of the Equipment Notes is secured by, among other things, a security
interest in the Aircraft leased to or owned by the Company.

         *        To be included on the face of each Global Certificate.
<PAGE>   68
                                      A-4



                  The Certificates represent fractional undivided interests in
the Trust and the Trust Property, and have no rights, benefits or interest in
respect of any assets or property other than the Trust Property.

                  Subject to and in accordance with the terms of the Agreement
and the Intercreditor Agreement, from and to the extent of funds then available
to the Trustee, there will be distributed on each January 2 and July 2 (a
"Regular Distribution Date"), commencing on January 2, 1999, to the Person in
whose name this Certificate is registered at the close of business on the 15th
day preceding the Regular Distribution Date, an amount in respect of the
Scheduled Payments due on such Regular Distribution Date on the Equipment Notes,
the receipt of which has been confirmed by the Trustee, equal to the product of
the percentage interest in the Trust evidenced by this Certificate and an amount
equal to the sum of such Scheduled Payments. Subject to and in accordance with
the terms of the Agreement and the Intercreditor Agreement, in the event that
Special Payments on the Equipment Notes are received by the Trustee, from funds
then available to the Trustee, there shall be distributed on the applicable
Special Distribution Date, to the Person in whose name this Certificate is
registered at the close of business on the 15th day preceding the Special
Distribution Date, an amount in respect of such Special Payments on the
Equipment Notes, the receipt of which has been confirmed by the Trustee, equal
to the product of the percentage interest in the Trust evidenced by this
Certificate and an amount equal to the sum of such Special Payments so received.
If a Regular Distribution Date or Special Distribution Date is not a Business
Day, distribution shall be made on the immediately following Business Day with
the same force and effect as if made on such Regular Distribution Date or
Special Distribution Date and no interest shall accrue during the intervening
period. The Trustee shall mail notice of each Special Payment and the Special
Distribution Date therefor to the Certificateholder of this Certificate.

                  The Certificates do not represent a direct obligation of, or
an obligation guaranteed by, or an interest in, the Company or the Trustee or
any of their affiliates. The Certificates are limited in right or payment, all
as more specifically set forth on the face hereof and in the Agreement. All
payments or distributions made to Certificateholders under the Agreement shall
be made only from the Trust Property and only to the extent that the Trustee
shall have sufficient income or proceeds from the Trust Property to make such
payments in accordance with the terms of the Agreement. Each Certificate-holder
of this Certificate, by its acceptance hereof, agrees that it will look solely
to the income and proceeds from the Trust Property to the extent available for
distribution to such Certificateholder as provided in the Agreement. This
Certificate does not purport to summarize the Agreement and reference is made to
the Agreement for information with respect to the interests, rights, benefits,
obligations, proceeds, and duties evidenced hereby. A copy of the Agreement may
be examined during normal business hours at the principal office of the Trustee,
and at such other places, if any, designated by the Trustee, by any
Certificateholder upon request.

                  The Agreement permits, with certain exceptions therein
provided, the amendment thereof and the modification of the rights and
obligations of the Company and the rights of the Certificateholders under the
Agreement at any time by the Company and the Trustee with the consent of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not less than a majority in interest in the Trust. Any
such consent by the Certificateholder of this Certificate shall be conclusive
and binding on such Certificateholder and 
<PAGE>   69
                                      A-5


upon all future Certificateholders of this Certificate and of any Certificate
issued upon the transfer hereof or in exchange hereof or in lieu hereof whether
or not notation of such consent is made upon this Certificate. The Agreement
also permits the amendment thereof, in certain limited circumstances, without
the consent of the Certificateholders of any of the Certificates.

                  As provided in the Agreement and subject to certain
limitations therein set forth, the transfer of this Certificate is registrable
in the Register upon surrender of this Certificate for registration of transfer
at the offices or agencies maintained by the Trustee in its capacity as
Registrar, or by any successor Registrar, in the Borough of Manhattan, the City
of New York, duly endorsed or accompanied by a written instrument of transfer in
form satisfactory to the Trustee and the Registrar duly executed by the
Certificateholder hereof or such Certificateholder's attorney duly authorized in
writing, and thereupon one or more new Certificates of authorized denominations
evidencing the same aggregate Fractional Undivided Interest in the Trust will be
issued to the designated transferee or transferees.

                  [The Holder of this Certificate is entitled to the benefits of
the Exchange and Registration Rights Agreement, dated as of October 6, 1998,
among the Company, the Trustee and the Initial Purchasers named therein (the
"Registration Rights Agreement"). In the event that no Registration Event has
occurred on or prior to the 210th day after the date of the issuance of the
Certificates, the interest rate per annum payable in respect of the Equipment
Notes and the Deposits shall be increased by 0.50%, from and including the 210th
day after the Issuance Date to but excluding the earlier of (i) the date on
which a Registration Event occurs and (ii) the date on which there cease to be
any Registrable Certificates (as defined in the Registration Rights Agreement).
In the event that the Shelf Registration Statement ceases to be effective at any
time during the period specified by Section 2(b)(B) of the Registration Rights
Agreement for more than 60 days, whether or not consecutive, during any 12-month
period, the interest rate per annum payable in respect of the Equipment Notes
and the Deposits shall be increased by 0.50% from the 61st day of the applicable
12-month period such Shelf Registration Statement ceases to be effective until
such time as the Shelf Registration Statement again becomes effective ( or, if
earlier, the end of the period specified by Section 2(b)(B) of the Registration
Rights Agreement).]*

                  Except as otherwise provided in the Agreement and
notwithstanding the above, the final distribution on this Certificate will be
made after notice mailed by the Trustee of the pendency of such distribution and
only upon presentation and surrender of this Certificate at the office or agency
of the Trustee specified in such notice.

                  Under certain circumstances set forth in Section 11.01 of the
Agreement, all of the Trustee's right, title and interest to the Trust Property
may be assigned, transferred and delivered to the Related Trustee of the Related
Trust pursuant to the Assignment and Assumption Agreement. Upon the
effectiveness of such Assignment and Assumption Agreement (the 

         *        To be included only on each Initial Certificate.
<PAGE>   70
                                      A-6


"Transfer"), the Trust shall be terminated, the Certificateholders shall receive
beneficial interests in the Related Trust in exchange for their interests in the
Trust equal to their respective beneficial interests in the Trust, the
Certificates representing Fractional Undivided Interests in the Trust shall be
deemed for all purposes of the Agreement and the Related Pass Through Trust
Agreement to be certificates representing the same fractional undivided
interests in the Related Trust and its trust property. Each Certificateholder,
by its acceptance of this Certificate or a beneficial interest herein, agrees to
be bound by the Assignment and Assumption Agreement and subject to the terms of
the Related Pass Through Trust Agreement as a certificateholder thereunder. From
and after the Transfer, unless and to the extent the context otherwise requires,
references herein to the Trust, the Agreement and the Trustee shall constitute
references to the Related Trust, the Related Pass Through Trust Agreement and
trustee of the Related Trust, respectively.

                  The Certificates are issuable only as registered Certificates
without coupons in minimum denominations of [$100,000]* [$1,000]** Fractional
Undivided Interest and integral multiples of $1,000 in excess thereof except
that one Certificate may be in a different denomination. As provided in the
Agreement and subject to certain limitations therein set forth, the Certificates
are exchangeable for new Certificates of authorized denominations evidencing the
same aggregate Fractional Undivided Interest in the Trust, as requested by the
Certificateholder surrendering the same.

                  No service charge will be made for any such registration of
transfer or exchange, but the Trustee shall require payment by the Holder of a
sum sufficient to cover any tax or governmental charge payable in connection
therewith.

                  Each Certificateholder or Investor that is not a United States
person within the meaning of Section 7701(a)(30) of the Internal Revenue Code,
as amended, by its acceptance of a Certificate or a beneficial interest therein,
agrees to indemnify and hold harmless the Trust and the Trustee from and against
any improper failure to withhold taxes from amounts payable to it or for its
benefit. Each Certificateholder and Investor, by its acceptance of this
Certificate or a beneficial interest herein, agrees to treat the Trust as a
grantor trust for all U.S. federal, state and local income tax purposes.

                  The Trustee, the Registrar, and any agent of the Trustee or
the Registrar may treat the person in whose name this Certificate is registered
as the owner hereof for all purposes, and neither the Trustee, the Registrar,
nor any such agent shall be affected by any notice to the contrary.

                  The obligations and responsibilities created by the Agreement
and the Trust created thereby shall terminate upon the distribution to
Certificateholders of all amounts required 


         *        To be included only on each Initial Certificate.

         **       To be included only on each Exchange Certificate.
<PAGE>   71
                                      A-7


to be distributed to them pursuant to the Agreement and the disposition of all
property held as part of the Trust Property.

                  UNTIL THE TRANSFER, THE AGREEMENT AND THIS CERTIFICATE SHALL
BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF
DELAWARE AND THE OBLIGATIONS, RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER SHALL
BE DETERMINED IN ACCORDANCE WITH SUCH LAWS. FROM AND AFTER THE TRANSFER, THE
AGREEMENT AND THIS CERTIFICATE SHALL BE GOVERNED AND CONSTRUED IN ACCORDANCE
WITH THE LAWS OF THE STATE OF NEW YORK AND THE OBLIGATIONS, RIGHTS AND REMEDIES
OF THE PARTIES HEREUNDER SHALL BE DETERMINED IN ACCORDANCE WITH SUCH LAWS.

                  Unless the certificate of authentication hereon has been
executed by the Trustee, by manual signature, this Certificate shall not be
entitled to any benefit under the Agreement or be valid for any purpose.
<PAGE>   72
                                      A-8



                  IN WITNESS WHEREOF, the Trustee has caused this Certificate to
be duly executed.

Dated:  October 6, 1998

                                        AMERICA WEST AIRLINES PASS THROUGH 
                                          TRUST, SERIES 1998-1A-O



                                        By:  WILMINGTON TRUST COMPANY, not in 
                                             its individual capacity but solely 
                                             as Trustee


                                        By:  
                                             Name:
                                             Title:

[Attest:


- ----------------------
Authorized Signature]
<PAGE>   73
                                      A-9



              [FORM OF THE TRUSTEE'S CERTIFICATE OF AUTHENTICATION]

                    This is one of the Certificates referred
                      to in the within-mentioned Agreement.



                                       WILMINGTON TRUST COMPANY,
                                       not in its individual capacity but solely
                                       as Trustee


                                       By:                                      
                                          --------------------------------------
                                           Authorized Officer
<PAGE>   74
                                      A-10



                             FORM OF TRANSFER NOTICE

                  FOR VALUE RECEIVED the undersigned registered holder hereby
sell(s), assign(s) and transfer(s) unto

Insert Taxpayer Identification No.






please print or typewrite name and address including zip code of assignee



the within Certificate and all rights thereunder, hereby irrevocably
constituting and appointing



attorney to transfer said Certificate on the books of the Trustee with full
power of substitution in the premises.

                     [THE FOLLOWING PROVISION TO BE INCLUDED
                               ON ALL CERTIFICATES
                         EXCEPT REGULATION S GLOBAL AND
                      REGULATION S DEFINITIVE CERTIFICATES]

                  In connection with any transfer of this Certificate occurring
prior to the date that is the earlier of the date of an effective Registration
Statement or the date two years after the later of the original issuance of this
Certificate or the last date on which this Certificate was held by America West
Airlines, Inc., the Trustee or any affiliate of such Persons, the undersigned
confirms that without utilizing any general solicitation or general advertising
that:

                                   [Check One]

[ ] (a) this Certificate is being transferred in compliance with the exemption
from registration under the Securities Act of 1933, as amended, provided by Rule
144A thereunder.

                                       or

[ ] (b) this Certificate is being transferred other than in accordance with (a)
above and documents are being furnished that comply with the conditions of
transfer set forth in this Certificate and the Agreement.

If neither of the foregoing boxes is checked, the Trustee or other Registrar
shall not be obligated to register this Certificate in the name of any Person
other than the Holder hereof unless and until the conditions to any such
transfer of registration set forth herein and in Section 3.06 of the Agreement
shall have been satisfied.
<PAGE>   75
                                      A-11


Date:__________________                              [Name of Transferor]       
                                                     NOTE: The signature must
                                                     correspond with the name as
                                                     written upon the face of
                                                     the within-mentioned
                                                     instrument in every
                                                     particular, without
                                                     alteration or any change
                                                     whatsoever.
Signature Guarantee: ______________________

TO BE COMPLETED BY PURCHASER IF (a) ABOVE IS CHECKED.

                  The undersigned represents and warrants that it is purchasing
this Certificate for its own account or an account with respect to which it
exercises sole investment discretion and that it and any such account is a
"qualified institutional buyer" within the meaning of Rule 144A under the
Securities Act of 1933, as amended, and is aware that the sale to it is being
made in reliance on Rule 144A and acknowledges that it has received such
information regarding the Company as the undersigned has requested pursuant to
Rule 144A or has determined not to request such information and that it is aware
that the transferor is relying upon the undersigned's foregoing representations
in order to claim the exemption from registration provided by Rule 144A.

Dated:__________________    _____________________________
                            NOTE:        To be executed by an executive officer.
<PAGE>   76
                                                                       EXHIBIT B

             FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION WITH
               TRANSFERS OF CERTIFICATES PURSUANT TO REGULATION S 

                                                                          [date]

Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE  19890-0001

Attention:  Corporate Trust Trustee Administration

         Re:      America West Airlines Pass Through Trust (the "Trust"),
                  Series 1998-1A-O, America West Airlines Pass Through
                  Certificates, Series 1998-1A-O (the "Certificates")          

Sirs:

                  In connection with our proposed sale of $_____ Fractional
Undivided Interest of the Certificates, we confirm that such sale has been
effected pursuant to and in accordance with Regulation S under the Securities
Act of 1933, as amended, and, accordingly, we represent that:

                  (1) the offer of the Certificates was not made to a person in
         the United States or to or for the account or benefit of a U.S. person;

                  (2) either (a) at the time the buy order was originated, the
         transferee was outside the United States or we and any person acting on
         our behalf reasonably believed that the transferee was outside the
         United States or (b) the transaction was executed in, on or through the
         facilities of a designated off-shore securities market and neither we
         nor any person acting on our behalf knows that the transaction has been
         pre-arranged with a buyer in the United States;

                  (3) no directed selling efforts have been made in the United
         States in contravention of the requirements of Rule 903(a) or Rule
         904(a) of Regulation S, as applicable; and

                  (4) the transaction is not part of a plan or scheme to evade
         the registration requirements of the Securities Act.

                  In addition, if the sale is made during a restricted period
and the provisions of Rule 903(b)(2) or Rule 904(b)(1) of Regulation S are
applicable thereto, we confirm that such sale has been made in accordance with
the applicable provisions of Rule 903(b)(2) or Rule 904(b)(1), as the case may
be.

                  You and America West Airlines, Inc. are entitled to rely upon
this letter and are irrevocably authorized to produce this letter or a copy
hereof to any interested party in any 
<PAGE>   77
                                      B-2

administrative or legal proceedings or official inquiry with respect to the
matters covered hereby. Terms used in this certificate have the meanings set
forth in Regulation S.

                                        Very truly yours,

                                        [Name of Transferor]
<PAGE>   78
                                                                       EXHIBIT C


                FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION
                        WITH TRANSFERS OF CERTIFICATES TO
                   NON-QIB INSTITUTIONAL ACCREDITED INVESTORS

                                                                          [date]

Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE  19890-0001
Attention:  Corporate Trust Trustee Administration

America West Airlines, Inc.
4000 East Sky Harbor Boulevard
Phoenix, Arizona  85043



                              AMERICA WEST AIRLINES
               PASS THROUGH TRUST, SERIES 1998-1A-O (the "Trust")
                   Pass Through Certificates, Series 1998-1A-O
                              (the "Certificates")


Ladies and Gentlemen:

         In connection with our proposed purchase of U.S. $[_____________]
Fractional Undivided Interest of Certificates, we confirm that:

         1. We understand that any subsequent transfer of the Certificates is
subject to certain restrictions and conditions set forth in the Pass Through
Trust Agreement, dated as of October 6, 1998, between America West Airlines,
Inc. (the "Company") and Wilmington Trust Company (the "Trustee") relating to
the Certificates, and we agree to be bound by, and not to resell, pledge or
otherwise transfer the Certificates except in compliance with, such restrictions
and conditions and the Securities Act of 1933, as amended (the "Securities
Act").

         2. We are purchasing Certificates having an aggregate principal amount
of not less than $100,000 and each account (if any) for which we are purchasing
Certificates is purchasing Certificates having an aggregate principal amount of
not less than $100,000.

         3. We understand that the Certificates have not been registered under
the Securities Act, that the Certificates are being sold to us in a transaction
that is exempt from the registration requirements of the Securities Act and that
the Certificates may not be offered or resold except as permitted in the
following sentence. We agree, on our own behalf and on behalf of any accounts
for which we are acting as hereinafter stated, that, if we should sell any
Certificates within two years after the later of the original issuance of such
Certificate and the last date on which such 
<PAGE>   79
                                      C-2


Certificate is owned by the Company, the Trustee or any affiliate of any of such
persons, we will do so only (A) to the Company, (B) in accordance with Rule 144A
under the Securities Act to a "qualified institutional buyer" (as defined
therein), (C) outside the United States in accordance with Rule 904 of
Regulation S under the Securities Act, (D) pursuant to the exemption from
registration provided by Rule 144 under the Securities Act or (E) pursuant to an
effective registration statement under the Securities Act, and we further agree
to provide to any person purchasing any of the Certificates from us a notice
advising such purchaser that resales of the Certificates are restricted as
stated herein.

         4. We understand that, on any proposed resale of any Certificates, we
will be required to furnish to the Company and the Trustee such certifications,
legal opinions and other information as the Company and the Trustee may
reasonably require to confirm that the proposed sale complies with the foregoing
restrictions. We further understand that the Certificates purchased by us will
bear a legend to the foregoing effect.

         5. We are an institutional "accredited investor" (as defined in Rule
501(a)(1), (2), (3) or (7) of Regulation D under the Securities Act) and have
such knowledge and experience in financial and business matters as to be capable
of evaluating the merits and risks of our investment in the Certificates, and we
and any accounts for which we are acting are each able to bear the economic risk
of our or their investments.

         6. We are acquiring the Certificates purchased by us for our own
account or for one or more accounts (each of which is an institutional
"accredited investor") as to each of which we exercise sole investment
discretion and not with a view to any distribution of the Certificates, subject,
nevertheless to the understanding that the disposition of our property shall at
all times be and remain within our control.

                  You are entitled to rely upon this letter and are irrevocably
authorized to produce this letter or a copy thereof to any interested party in
any administrative or legal proceedings or official inquiry with respect to the
matters covered hereby.

                                        Very truly yours,



                                        By:
                                           -------------------------------------
                                             Name:
                                             Title:
<PAGE>   80
                                                                       EXHIBIT D

                   FORM OF ASSIGNMENT AND ASSUMPTION AGREEMENT
            America West Airlines Pass Through Trust, Series 1998-1A


                  ASSIGNMENT AND ASSUMPTION AGREEMENT, dated ____________, 199_
(the "Agreement"), between Wilmington Trust Company, a Delaware banking
corporation ("WTC"), not in its individual capacity except as expressly provided
herein, but solely as trustee under the Pass Through Trust Agreement dated as of
October 6, 1998 (as amended, modified or otherwise supplemented from time to
time, the "Pass Through Trust Agreement") in respect of the America West
Airlines Pass Through Trust, Series 1998-1A-O (the "Assignor"), and Wilmington
Trust Company, a Delaware banking corporation, not in its individual capacity
except as expressly provided herein, but solely as trustee under the Pass
Through Trust Agreement dated as of October 6, 1998 (the "New Pass Through Trust
Agreement") in respect of the America West Airlines Pass Through Trust, Series
1998-1A-S (the "Assignee").

                              W I T N E S S E T H:

                  WHEREAS, the parties hereto desire to effect on the date
hereof (the "Transfer Date") (a) the transfer by the Assignor to the Assignee of
all of the right, title and interest of the Assignor in, under and with respect
to, among other things, the Trust Property and each of the documents listed in
Schedule I hereto (the "Scheduled Documents") and (b) the assumption by the
Assignee of the obligations of the Assignor (i) under the Scheduled Documents
and (ii) in respect of the Certificates issued under the Pass Through Trust
Agreement; and

                  WHEREAS, the Scheduled Documents permit such transfer upon
satisfaction of certain conditions heretofore or concurrently herewith being
complied with;

                  NOW, THEREFORE, in consideration of the premises and of the
mutual covenants and agreements herein contained, the parties hereto do hereby
agree as follows (capitalized terms used herein without definition having the
meaning ascribed thereto in the Pass Through Trust Agreement):

                  1        Assignment. The Assignor does hereby sell, assign,
convey, transfer and set over unto the Assignee as of the Transfer Date all of
its present and future right, title and interest in, under and with respect to
the Trust Property and the Scheduled Documents and each other contract,
agreement, document or instrument relating to the Trust Property or the
Scheduled Documents (such other contracts, agreements, documents or instruments,
together with the Scheduled Documents, to be referred to as the "Assigned
Documents"), and any proceeds therefrom, together with all documents and
instruments evidencing any of such right, title and interest.

                  2        Assumption. The Assignee hereby assumes for the
benefit of the Assignor and each of the parties listed in Schedule II hereto
(collectively, the "Beneficiaries") all of the duties and obligations of the
Assignor, whenever accrued, pursuant to the Assigned Documents and hereby
confirms that it shall be deemed a party to each of the Assigned Documents to
which the Assignor is a party and shall be bound by all the terms thereof
(including the agreements and obligations of the Assignor set forth therein) as
if therein named as the Assignor. Further, the Assignee hereby assumes for the
benefit of the Assignor and the Beneficiaries all of the duties

<PAGE>   81
                                      D-2


and obligations of the Assignor under the Outstanding Certificates and hereby
confirms that the Certificates representing Fractional Undivided Interests under
the Pass Through Trust Agreement shall be deemed for all purposes of the Pass
Through Trust Agreement and the New Pass Through Trust Agreement to be
certificates representing the same fractional undivided interests under the New
Pass Through Trust Agreement equal to their respective beneficial interests in
the trust created under the Pass Through Trust Agreement.

                  3        Effectiveness. This Agreement shall be effective upon
the execution and delivery hereof by the parties hereto, and each
Certificateholder, by its acceptance of its Certificate or a beneficial interest
therein, agrees to be bound by the terms of this Agreement.

                  4        Payments. The Assignor hereby covenants and agrees to
pay over to the Assignee, if and when received following the Transfer Date, any
amounts (including any sums payable as interest in respect thereof) paid to or
for the benefit of the Assignor that, under Section 1 hereof, belong to the
Assignee.

                  5        Further Assurances. The Assignor shall, at any time
and from time to time, upon the request of the Assignee, promptly and duly
execute and deliver any and all such further instruments and documents and take
such further action as the Assignee may reasonably request to obtain the full
benefits of this Agreement and of the right and powers herein granted. The
Assignor agrees to deliver the Global Certificates, and all Trust Property, if
any, then in the physical possession of the Assignor, to the Assignee.

                  6        Representations and Warranties.  (a)  The Assignee 
represents and warrants to the Assignor and each of the Beneficiaries that:

                  (i) it has all requisite power and authority and legal right
         to enter into and carry out the transactions contemplated hereby and to
         carry out and perform the obligations of the "Pass Through Trustee"
         under the Assigned Documents;

                  (ii) on and as of the date hereof, the representations and
         warranties of the Assignee set forth in Section 7.15 of the New Pass
         Through Trust Agreement are true and correct.

                  (b) The Assignor represents and warrants to the Assignee that:

                  (i) it is duly incorporated, validly existing and in good
         standing under the laws of the State of Delaware and has the full trust
         power, authority and legal right under the laws of the State of
         Delaware and the United States pertaining to its trust and fiduciary
         powers to execute and deliver this Agreement;

                  (ii) the execution and delivery by it of this Agreement and
         the performance by it of its obligations hereunder have been duly
         authorized by it and will not violate its articles of association or
         by-laws or the provisions of any indenture, mortgage, contract or other
         agreement to which it is a party or by which it is bound; and

                  (iii) this Agreement constitutes the legal, valid and binding
         obligations of it enforceable against it in accordance with its terms,
         except as the same may be limited by applicable bankruptcy, insolvency,
         reorganization, moratorium or similar laws affecting 
<PAGE>   82
                                      D-3


         the rights of creditors generally and by general principles of equity,
         whether considered in a proceeding at law or in equity.

                  7        GOVERNING LAW.  THIS AGREEMENT SHALL BE GOVERNED BY 
AND CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK INCLUDING
MATTERS OF CONSTRUCTION, VALIDITY AND PERFORMANCE, WITHOUT GIVING EFFECT TO
PRINCIPLES OF CONFLICTS OF LAWS.

                  8        Counterparts. This Agreement may be executed in any
number of counterparts, all of which together shall constitute a single
instrument. It shall not be necessary that any counterpart be signed by both
parties so long as each party shall sign at least one counterpart.

                  9        Third Party Beneficiaries. The Assignee hereby
agrees, for the benefit of the Beneficiaries, that its representations,
warranties and covenants contained herein are also intended to be for the
benefit of each Beneficiary, and each Beneficiary shall be deemed to be an
express third party beneficiary with respect thereto, entitled to enforce
directly and in its own name any rights or claims it may have against such party
as such beneficiary.

                  IN WITNESS WHEREOF, the parties hereto, through their
respective officers thereunto duly authorized, have duly executed this
Assignment as of the day and year first above written.

                                    ASSIGNOR:

                                    WILMINGTON TRUST COMPANY,
                                    not in its individual
                                    capacity except as
                                    expressly provided herein,
                                    but solely as trustee under
                                    the Pass Through Trust
                                    Agreement in respect of the
                                    America West Airlines Pass
                                    Through Trust 1998-1A-O


                                    By:
                                       -----------------------------------------
                                        Title:

                                    ASSIGNEE:

                                    WILMINGTON TRUST COMPANY,
                                    not in its individual
                                    capacity except as
                                    expressly provided herein,
                                    but solely as trustee under
                                    the Pass Through Trust
                                    Agreement in respect of the
                                    America West Airlines Pass
                                    Through Trust 1998-1A-S


                                    By:
                                       -----------------------------------------
                                        Title:
<PAGE>   83
                                                                      Schedule I

                         Schedule of Assigned Documents

(1)      Intercreditor Agreement dated as of October 6, 1998 among the Trustee,
         the Other Trustees, the Liquidity Provider, the liquidity provider, if
         any, relating to the Certificates issued under (and as defined in) each
         of the Other Pass Through Trust Agreements and the Subordination Agent.

(2)      Registration Rights Agreement dated as of October 6, 1998 among the
         Initial Purchasers, the Trustee, the Other Trustees, and the Company.

(3)      Escrow and Paying Agent Agreement (Class A) dated as of October 6, 1998
         among the Escrow Agent, the Initial Purchasers, the Trustee and the
         Paying Agent.

(4)      Note Purchase Agreement dated as of October 6, 1998 among the Company,
         the Trustee, the Other Trustees, the Depositary, the Escrow Agent, the
         Paying Agent and the Subordination Agent.

(5)      Deposit Agreement (Class A) dated as of October 6, 1998 between the
         Escrow Agent and the Depositary.

(6)      Each of the Operative Agreements (as defined in the Participation
         Agreement for each Aircraft) in effect as of the Transfer Date.
<PAGE>   84
                                                                     Schedule II

                            Schedule of Beneficiaries

Wilmington Trust Company, not in its individual capacity but solely as
Subordination Agent.

Wilmington Trust Company, not in its individual capacity but solely as Paying 
Agent

ABN AMRO Bank, N.V., acting through its Chicago branch, as Liquidity Provider

America West Airlines, Inc.

Morgan Stanley & Co. Incorporated, as Initial Purchaser

Donaldson, Lufkin & Jenrette Securities Corporation, as Initial Purchaser

Merrill Lynch, Pierce, Fenner & Smith Incorporated, as Initial Purchaser

Salomon Smith Barney Inc., as Initial Purchaser

Wilmington Trust Company, as Escrow Agent

Each of the other parties to the Assigned Documents
<PAGE>   85
                                                                       EXHIBIT E

            FORM OF NOTICE TO DESIGNATE NOMINEE AS WITHHOLDING AGENT
          (Treas. Reg. Section 1.1445-8(f); 17 C.F.R. 240.10b-17(b)(1))

                                                                          [DATE]

National Association of
Securities Dealers, Inc.
Market Operations
80 Merritt Blvd.
Trumbull, CT  06611

         Re:      America West Airlines Pass Through Trust, Series 1998-1A-O
                  Pass Through Certificates, Series 1998-1A-O

                    With respect to distributions to be made on [INSERT
DISTRIBUTION DATE] to holders of the above-referenced Pass Through Certificates
in the amount of $ ____ per $1,000 principal amount of Certificate, we hereby
designate the appropriate nominees to withhold from amounts distributable to any
non-U.S. Person such amounts as required by Section 1446 of the Internal Revenue
Code of 1986, as amended. The term "non-U.S. Person" means any person or entity
that, for U.S. federal income tax purposes, is not a "U.S. Person." "U.S.
Person" for this purpose means a citizen or resident of the United States, a
corporation, partnership or other entity created or organized under the laws of
the United States or any political subdivision thereof, or an estate or trust,
the income of which is subject to U.S. federal income taxation regardless of its
source. The date of record for determining holders of Certificates entitled to
receive the distribution on [INSERT DISTRIBUTION DATE] is [INSERT RELATED RECORD
DATE].

                                                              Very truly yours,









<PAGE>   1
                                                                     EXHIBIT 4.5










                          PASS THROUGH TRUST AGREEMENT

                           Dated as of October 6, 1998

                                     between

                           AMERICA WEST AIRLINES, INC.

                                       And

                            WILMINGTON TRUST COMPANY,

                                   as Trustee

           America West Airlines Pass Through Trust, Series 1998-1A-S

            6.87% Initial Pass Through Certificates, Series 1998-1A-S
           6.87% Exchange Pass Through Certificates, Series 1998-1A-S





<PAGE>   2
Reconciliation and tie between America West Airlines Pass Through Trust
Agreement, Series 1998-1A-S dated as of October 6, 1998, and the Trust Indenture
Act of 1939. This reconciliation does not constitute part of the Pass Through
Trust Agreement.

          Trust Indenture Act                        Pass Through Trust
            of 1939 Section                           Agreement Section
            ---------------                           -----------------
            310(a)(1)                                  7.08
               (a)(2)                                  7.08
            312(a)                                     3.05; 8.01; 8.02
            313(a)                                     7.06; 8.03
            314(a)                                     8.04(a),(c) & (d)
            (a)(4)                                     8.04(e)
            (c)(1)                                     1.02
            (c)(2)                                     1.02
            (d)(1)                                     7.13; 11.01
            (d)(2)                                     7.13; 11.01
            (d)(3)                                     2.01
            (e)                                        1.02
            315(b)                                     7.02
            316(a)(last sentence)                      1.04(c)
               (a)(1)(A)                               6.04
               (a)(1)(B)                               6.05
               (b)                                     6.06
               (c)                                     1.04(e)
            317(a)(1)                                  6.03
               (b)                                     7.13
            318(a)                                    12.06
<PAGE>   3
                                TABLE OF CONTENTS

SECTION                                                                     PAGE
- -------                                                                     ----

ARTICLE I  DEFINITIONS.........................................................2
      Section 1.01.     Definitions............................................2
      Section 1.02.     Compliance Certificates and Opinions..................13
      Section 1.03.     Form of Documents Delivered to Trustee................14
      Section 1.04.     Directions of Certificateholders......................14

ARTICLE II  ACQUISITION OF TRUST PROPERTY.....................................15
      Section 2.01.     Acquisition of Trust Property.........................15
      Section 2.02.     Acceptance by Trustee.................................16
      Section 2.03.     Limitation of Powers..................................16

ARTICLE III  THE CERTIFICATES.................................................16
      Section 3.01.     Title, Form, Denomination and Execution of
                        Certificates..........................................16
      Section 3.02.     Restrictive Legends...................................18
      Section 3.03.     Authentication of Certificates........................20
      Section 3.04.     Transfer and Exchange.................................20
      Section 3.05.     Book-Entry Provisions for Restricted Global
                        Certificates and Regulation S Global
                        Certificates..........................................21
      Section 3.06.     Special Transfer Provisions...........................23
      Section 3.07.     Mutilated, Destroyed, Lost or Stolen
                        Certificates..........................................25
      Section 3.08.     Persons Deemed Owners.................................26
      Section 3.09.     Cancellation..........................................26
      Section 3.10.     Temporary Certificates................................26
      Section 3.11.     Limitation of Liability for Payments..................27

ARTICLE IV  DISTRIBUTIONS; STATEMENTS TO CERTIFICATEHOLDERS...................27
      Section 4.01.     Certificate Account and Special Payments Account......27
      Section 4.02.     Distributions from Certificate Account and
                        Special Payments Account..............................27
      Section 4.03.     Statements to Certificateholders......................29
      Section 4.04.     Investment of Special Payment Moneys..................30

ARTICLE V  THE COMPANY........................................................30
      Section 5.01.     Maintenance of Corporate Existence....................30
      Section 5.02.     Consolidation, Merger, Etc............................31

ARTICLE VI  DEFAULT...........................................................31
      Section 6.01.     Events of Default.....................................31
      Section 6.02.     Incidents of Sale of Equipment Notes..................34
      Section 6.03.     Judicial Proceedings Instituted by Trustee;
                        Trustee May Bring Suit................................34
      Section 6.04.     Control by Certificateholders.........................34
      Section 6.05.     Waiver of Past Defaults...............................35
<PAGE>   4
SECTION                                                                     PAGE
- -------                                                                     ----

      Section 6.06.     Right of Certificateholders to Receive Payments
                        Not to Be Impaired....................................35
      Section 6.07.     Certificateholders May Not Bring Suit Except
                        Under Certain Conditions..............................36
      Section 6.08.     Remedies Cumulative...................................36

ARTICLE VII  THE TRUSTEE......................................................36
      Section 7.01.     Certain Duties and Responsibilities...................36
      Section 7.02.     Notice of Defaults....................................37
      Section 7.03.     Certain Rights of Trustee.............................37
      Section 7.04.     Not Responsible for Recitals or Issuance of
                        Certificates..........................................38
      Section 7.05.     May Hold Certificates.................................39
      Section 7.06.     Money Held in Trust...................................39
      Section 7.07.     Compensation and Reimbursement........................39
      Section 7.08.     Corporate Trustee Required; Eligibility...............40
      Section 7.09.     Resignation and Removal; Appointment of
                        Successor.............................................40
      Section 7.10.     Acceptance of Appointment by Successor................42
      Section 7.11.     Merger, Conversion, Consolidation or Succession
                        to Business...........................................42
      Section 7.12.     Maintenance of Agencies...............................42
      Section 7.13.     Money for Certificate Payments to Be Held in
                        Trust.................................................44
      Section 7.14.     Registration of Equipment Notes in Name of
                        Subordination Agent...................................44
      Section 7.15.     Representations and Warranties of Trustee.............44
      Section 7.16.     Withholding Taxes, Information Reporting..............45
      Section 7.17.     Trustee's Liens.......................................46
      Section 7.18.     Preferential Collection of Claims.....................46

ARTICLE VIII  CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE................46
      Section 8.01.     The Company to Furnish Trustee with Names and
                        Addresses of Certificateholders.......................46
      Section 8.02.     Preservation of Information; Communications to
                        Certificateholders....................................46
      Section 8.03.     Reports by Trustee....................................46
      Section 8.04.     Reports by the Company................................46

ARTICLE IX  SUPPLEMENTAL AGREEMENTS...........................................48
      Section 9.01.     Supplemental Agreements Without Consent of
                        Certificateholders....................................48
      Section 9.02.     Supplemental Agreements with Consent of
                        Certificateholders....................................49
      Section 9.03.     Documents Affecting Immunity or Indemnity.............50
      Section 9.04.     Execution of Supplemental Agreements..................50
      Section 9.05.     Effect of Supplemental Agreements.....................50
      Section 9.06.     Conformity with Trust Indenture Act...................50
      Section 9.07.     Reference in Certificates to Supplemental
                        Agreements............................................50


                                       ii
<PAGE>   5
SECTION                                                                     PAGE
- -------                                                                     ----

ARTICLE X  AMENDMENTS TO INDENTURES AND FINANCING DOCUMENTS...................51
      Section 10.01.    Amendments and Supplements to Indentures and
                        Financing Documents...................................51

ARTICLE XI  TERMINATION OF TRUST..............................................51
      Section 11.01.    Termination of the Trust..............................51

ARTICLE XII  MISCELLANEOUS PROVISIONS.........................................52
      Section 12.01.    Limitation on Rights of Certificateholders............52
      Section 12.02.    Certificates Nonassessable and Fully Paid.............52
      Section 12.03.    Notices...............................................53
      Section 12.04.    Governing Law.........................................54
      Section 12.05.    Severability of Provisions............................54
      Section 12.06.    Trust Indenture Act Controls..........................54
      Section 12.07.    Effect of Headings and Table of Contents..............54
      Section 12.08.    Successors and Assigns................................54
      Section 12.09.    Benefits of Agreement.................................54
      Section 12.10.    Legal Holidays........................................55
      Section 12.11.    Counterparts..........................................55
      Section 12.12.    Intention of Parties..................................55


Exhibit A - Form of Certificate to Request Removal of Restricted Legend
Exhibit B - Form of Certificate to be Delivered by an Institutional Accredited
            Investor


                                       iii
<PAGE>   6
                          PASS THROUGH TRUST AGREEMENT


            This PASS THROUGH TRUST AGREEMENT, dated as of October 6, 1998, (the
"Agreement") between AMERICA WEST AIRLINES, INC., a Delaware corporation, and
WILMINGTON TRUST COMPANY, as Trustee, is made with respect to the formation of
America West Airlines Pass Through Trust, Series 1998-1A-S and the 6.87% America
West Airlines Pass Through Trust, Series 1998-1A-S Pass Through Certificates
representing fractional undivided interests in the Trust.

                                   WITNESSETH:

            WHEREAS, the Company has obtained commitments from AVSA for the
delivery of certain Aircraft;

            WHEREAS, as of the Transfer Date, the Company will have financed (or
refinanced) the acquisition all or a portion of the Aircraft either (i) through
separate leveraged lease transactions in which the Company leases such aircraft
(collectively, the "Leased Aircraft") or (ii) through separate secured loan
transactions in which the Company owns such Aircraft (collectively, the "Owned
Aircraft");

            WHEREAS, as of the Transfer Date, in the case of each Leased
Aircraft, each Owner Trustee, acting on behalf of the corresponding Owner
Participant, will have issued pursuant to an Indenture, on a non-recourse basis,
three (or, subject to satisfaction of certain preconditions contained in the
Note Purchase Agreement, four) series of Equipment Notes in order to finance a
portion of its purchase price of such Leased Aircraft;

            WHEREAS, as of the Transfer Date, in the case of each Owned
Aircraft, the Company, will have issued pursuant to an Indenture, on a recourse
basis, three (or, subject to satisfaction of certain preconditions contained in
the Note Purchase Agreement, four) series of Equipment Notes to finance a
portion of the purchase price of such Owned Aircraft;

            WHEREAS, as of the Transfer Date, the Related Trustee will assign,
transfer and deliver all of such trustee's right, title and interest to the
trust property held by the Related Trustee to the Trustee pursuant to the
Assignment and Assumption Agreement;

            WHEREAS, the Trustee, effective only, but automatically, upon
execution and delivery of the Assignment and Assumption Agreement, will be
deemed to have declared the creation of the Trust for the benefit of the
Certificateholders, and each Holder of Certificates outstanding as of the
Transfer Date, as the grantors of the Trust, by their respective acceptances of
the Certificates, will join in the creation of this Trust with the Trustee;

            WHEREAS, all Certificates deemed issued by the Trust will evidence
fractional undivided interests in the Trust and will convey no rights, benefits
or interests in respect of any property other than the Trust Property except for
those Certificates to which an Escrow Receipt (as defined below) has been
affixed;
<PAGE>   7
                                      -2-


            WHEREAS, the Company has duly authorized the execution, delivery and
effectiveness of this Agreement as the "issuer", as such term is defined in and
solely for purposes of the Securities Act, of the Certificates deemed to be
issued pursuant hereto and as the "obligor", as such term is defined in and
solely for purposes of the Trust Indenture Act of 1939, as amended, with respect
to all such Certificates and is undertaking to perform certain administrative
and ministerial duties hereunder and is also undertaking to pay the ongoing fees
and expenses of the Trustee;

            WHEREAS, upon the execution and delivery of the Assignment and
Assumption Agreement, all of the conditions and requirements necessary to make
this Agreement a valid, binding and legal instrument, enforceable in accordance
with its terms and for the purposes herein expressed, will have been done,
performed and fulfilled, and the execution and delivery of this Agreement in the
form and with the terms hereof will have been in all respects duly authorized;
and

            WHEREAS, upon issuance of the Exchange Certificates, if any, or the
effectiveness of the Shelf Registration Statement, this Agreement, as amended or
supplemented from time to time, will be subject to the provisions of the Trust
Indenture Act of 1939, and shall, to the extent applicable, be governed by such
provisions;

            NOW, THEREFORE, in consideration of the mutual agreements herein
contained, and of other good and valuable consideration the receipt and adequacy
of which are hereby acknowledged, the parties hereto agree as follows:


                                    ARTICLE I

                                   DEFINITIONS

            Section 1.01. Definitions. For all purposes of this Agreement,
except as otherwise expressly provided or unless the context otherwise requires:

            (1) the terms used in this Agreement, including in the recitals to
this Agreement, that are defined in this Article have the meanings assigned to
them in this Article, and include the plural as well as the singular;

            (2) all other terms used herein which are defined in the Trust
Indenture Act, either directly or by reference therein, or by the rules
promulgated under the Trust Indenture Act, have the meanings assigned to them
therein;

            (3) all references in this Agreement to designated "Articles",
"Sections", "Subsections" and other subdivisions are to the designated Articles,
Sections, Subsections and other subdivisions of this Agreement;

            (4) the words "herein", "hereof" and "hereunder" and other words of
similar import refer to this Agreement as a whole and not to any particular
Article, Section, Subsection or other subdivision; and
<PAGE>   8
                                      -3-


            (5) unless the context otherwise requires, whenever the words
"including", "include" or "includes" are used herein, it shall be deemed to be
followed by the phrase "without limitation".

            Affiliate: Means, with respect to any specified Person, any other
      Person directly or indirectly controlling or controlled by or under direct
      or indirect common control with such Person. For the purposes of this
      definition, "control" means the power, directly or indirectly, to direct
      the management and policies of such Person, whether through the ownership
      of voting securities or by contract or otherwise, and the terms
      "controlling" and "controlled" have meanings correlative to the foregoing.

            Agent Members: Has the meaning specified in Section 3.05.

            Agreement: Has the meaning specified in the initial paragraph
      hereto.

            Aircraft: Has the meaning specified in the Note Purchase Agreement.

            Aircraft Purchase Agreement: Has the meaning specified in the Note
      Purchase Agreement.

            Assignment and Assumption Agreement: Means the assignment and
      assumption agreement substantially in the form of Exhibit D to the Related
      Trust to be executed and delivered in accordance with Section 11.01 of the
      Related Pass Through Trust Agreement.

            Authorized Agent: Means any Paying Agent or Registrar for the
      Certificates.

            Avoidable Tax: Means a state or local tax (i) upon (w) the Trust,
      (x) the Trust Property, (y) Certificateholders or (z) the Trustee for
      which the Trustee is entitled to seek reimbursement from the Trust
      Property, and (ii) which would be avoided if the Trustee were located in
      another state, or jurisdiction within a state, within the United States. A
      tax shall not be an Avoidable Tax if the Company or any Owner Trustee
      shall agree to pay, and shall pay, such tax.

            AVSA: Means AVSA S.A.R.L., an affiliate of Airbus Industrie G.I.E.

            Business Day: Means any day other than a Saturday, a Sunday or a day
      on which commercial banks are required or authorized to close in Phoenix,
      Arizona, New York, New York, Wilmington, Delaware or, so long as any
      Certificate is outstanding, the city and state in which the Trustee or any
      Loan Trustee maintains its Corporate Trust Office or receives and
      disburses funds.

            Cedel: Means Cedel Bank societe anonyme.

            Certificate: Means any one of the Initial Certificates or Exchange
      Certificates issued by the Related Trust and that are "Outstanding" (as
      defined in the Related Pass Through Trust Agreement) as of the Transfer
      Date (the "Transfer Date Certificates") and
<PAGE>   9
                                      -4-


      any such Initial Certificates or Exchange Certificates issued in exchange
      therefor or replacement thereof pursuant to this Agreement.

            Certificate Account: Means the account or accounts created and
      maintained pursuant to Section 4.01(a).

            Certificate Purchase Agreement: Means the Purchase Agreement dated
      September 24, 1998 among the Initial Purchasers and the Company, as the
      same may be amended, supplemented or otherwise modified from time to time
      in accordance with its terms.

            Certificateholder or Holder: Means the Person in whose name a
      Certificate is registered in the Register.

            Class D Certificateholder: Means, at any time, any holder of one or
      more pass through certificates issued by the America West Airlines Pass
      Through Trust, Series 1998-1D, if and when established.

            Company: Means America West Airlines, Inc., a Delaware corporation,
      or its successor in interest pursuant to Section 5.02, or (only in the
      context of provisions hereof, if any, where such reference is required for
      purposes of compliance with the Trust Indenture Act) any other "obligor"
      (within the meaning of the Trust Indenture Act) with respect to the
      Certificates.

            Controlling Party: Has the meaning specified in the Intercreditor
      Agreement.

            Corporate Trust Office: With respect to the Trustee or any Loan
      Trustee, means the office of such trustee in the city at which at any
      particular time its corporate trust business shall be principally
      administered.

            Definitive Certificates: Has the meaning specified in Section
      3.01(e).

            Delivery Period Termination Date: Has the meaning specified in the
      Related Pass Through Trust Agreement.

            Deposits: Has the meaning specified in the Deposit Agreement.

            Deposit Agreement: Means the Deposit Agreement dated as of October
      6, 1998 relating to the Certificates between the Depositary and the Escrow
      Agent, as the same may be amended, supplemented or otherwise modified from
      time to time in accordance with its terms.

            Depositary: Means ABN AMRO Bank N.V., acting through its Chicago
      branch.

            Direction: Has the meaning specified in Section 1.04(a).

            Distribution Date: Means any Regular Distribution Date or Special
      Distribution Date as the context requires.
<PAGE>   10
                                      -5-


            DTC: Means The Depository Trust Company, its nominees and their
      respective successors.

            EBO Date: Means the date set forth on Schedule 1 to the Lease as the
      "EBO Date".

            Equipment Notes: Means the equipment notes issued under the
      Indentures.

            Escrow Agent: Means, initially, Wilmington Trust Company, and any
      replacement or successor therefor appointed in accordance with the Escrow
      Agreement.

            Escrow Agreement: Means the Escrow and Paying Agent Agreement dated
      as of October 6, 1998 relating to the Certificates, among the Escrow
      Agent, the Escrow Paying Agent, the Related Trustee (and after the
      Transfer Date, the Trustee) and the Initial Purchasers, as the same may be
      amended, supplemented or otherwise modified from time to time in
      accordance with its terms.

            Escrow Paying Agent: Means the Person acting as paying agent under
      the Escrow Agreement.

            Escrow Receipt: Means the receipt substantially in the form annexed
      to the Escrow Agreement representing a fractional undivided interest in
      the funds held in escrow thereunder.

            Euroclear: Means Morgan Guaranty Trust Company of New York, Brussels
      Office, as operator of the Euroclear System.

            Event of Default: Means an Indenture Default under any Indenture
      pursuant to which Equipment Notes held by the Trust were issued.

            Exchange Certificates: Means the pass through certificates issued in
      exchange for the Initial Certificates pursuant to the Registration Rights
      Agreement and authenticated under the Related Pass Through Trust Agreement
      (prior to the Transfer Date) or hereunder (after the Transfer Date).

            Exchange Offer: Means the exchange offer which may be made pursuant
      to the Registration Rights Agreement to exchange Initial Certificates for
      Exchange Certificates.

            Exchange Offer Registration Statement: Means the registration
      statement that, pursuant to the Registration Rights Agreement, is filed by
      the Company with the SEC with respect to the exchange of Initial
      Certificates for Exchange Certificates.

            Final Legal Distribution Date: Means July 2, 2018.

            Final Withdrawal: Has the meaning specified in the Escrow Agreement.

            Final Withdrawal Date: Has the meaning specified in the Escrow
      Agreement.
<PAGE>   11
                                      -6-


            Financing Documents: With respect to any Equipment Note, means (i)
      the Indenture and the Participation Agreement relating to such Equipment
      Note, and (ii) in the case of any Equipment Note related to a Leased
      Aircraft, the Lease relating to such Leased Aircraft.

            Fractional Undivided Interest: Means the fractional undivided
      interest in the Trust that is evidenced by a Certificate.

            Global Certificates: Has the meaning specified in Section 3.01(d).

            Global Exchange Certificate: Has the meaning specified in Section
      3.01(f).

            Indenture: Means each of the separate trust indentures and mortgages
      relating to the Aircraft, each as specified or described in a Delivery
      Notice delivered pursuant to the Note Purchase Agreement or the related
      Participation Agreement, in each case as the same may be amended,
      supplemented or otherwise modified from time to time in accordance with
      its terms.

            Indenture Default: With respect to any Indenture, means any Event of
      Default (as such term is defined in such Indenture).

            Initial Certificates: Means the "Initial Certificates" issued and
      authenticated under the Related Pass Through Trust Agreement, and any
      certificates issued and authenticated hereunder, in each case, other than
      the Exchange Certificates.

            Initial Purchasers: Means, collectively, Morgan Stanley & Co.
      Incorporated, Donaldson, Lufkin & Jenrette Securities Corporation, Merrill
      Lynch, Pierce, Fenner & Smith Incorporated and Salomon Smith Barney Inc.

            Institutional Accredited Investor: Means an institutional investor
      that is an "accredited investor" within the meaning set forth in Rule
      501(a)(1), (2), (3) or (7) of Regulation D under the Securities Act.

            Intercreditor Agreement: Means the Intercreditor Agreement dated as
      of October 6, 1998 among the Related Trustee (and after the Transfer Date,
      the Trustee), the Related Other Trustees (and after the Transfer Date, the
      Other Trustees), the Liquidity Provider, the liquidity provider relating
      to the Certificates issued under (and as defined in) each of the Related
      Other Pass Through Trust Agreements, and Wilmington Trust Company, as
      Subordination Agent and as trustee thereunder, as amended, supplemented or
      otherwise modified from time to time in accordance with its terms.

            Investors: Means the Initial Purchasers together with all subsequent
      beneficial owners of the Certificates.

            Issuance Date: Means the date of the issuance of the Initial
      Certificates.

            Lease: Means, with respect to each Leased Aircraft, the lease
      between an Owner Trustee, as the lessor, and the Company, as the lessee,
      referred to in the related Indenture,
<PAGE>   12
                                      -7-


      as such lease may be amended, supplemented or otherwise modified in
      accordance with its terms.

            Leased Aircraft: Has the meaning specified in the second recital to
      this Agreement.

            Liquidity Facility: Means, initially, the Revolving Credit Agreement
      dated as of October 6, 1998 relating to the Certificates, between the
      Liquidity Provider and the Subordination Agent, as agent and trustee for
      the Trustee, and, from and after the replacement of such Agreement
      pursuant to the Intercreditor Agreement, the replacement liquidity
      facility therefor, in each case as amended, supplemented or otherwise
      modified from time to time in accordance with their respective terms.

            Liquidity Provider: Means, initially, ABN AMRO Bank N.V., acting
      through its Chicago branch, and any replacement or successor therefor
      appointed in accordance with the Intercreditor Agreement.

            Loan Trustee: With respect to any Equipment Note or the Indenture
      applicable thereto, means the bank or trust company designated as trustee
      under such Indenture, together with any successor to such trustee
      appointed pursuant thereto.

            Material Adverse Tax Event: Has the meaning specified in Section
      17.3(a)(4) of the Lease.

            Non-U.S. Person: Means a Person that is not a "U.S. person", as
      defined in Regulation S.

            Note Purchase Agreement: Means the Note Purchase Agreement dated as
      of October 6, 1998 among the Related Trustee (and after the Transfer Date,
      the Trustee), the Related Other Trustees (and after the Transfer Date, the
      Other Trustees), the Company, the Escrow Agent, the Escrow Paying Agent
      and the Subordination Agent, as the same may be amended, supplemented or
      otherwise modified from time to time, in accordance with its terms.

            Offering Circular: Means the Offering Memorandum dated September 24,
      1998 relating to the offering of the Certificates and the other
      certificates under the Related Other Pass Through Trust Agreements.

            Officer's Certificate: Means a certificate signed, (a) in the case
      of the Company, by any Vice President or more senior officer of the
      Company or, (b) in the case of an Owner Trustee or a Loan Trustee, a
      Responsible Officer of such Owner Trustee or such Loan Trustee, as the
      case may be.

            Opinion of Counsel: Means a written opinion of legal counsel who (a)
      in the case of counsel for the Company may be (i) the General Counsel of
      the Company, (ii) Cooley Godward LLP, (iii) Vedder, Price, Kaufman,
      Kammholz & Day, or (iv) such other counsel designated by the Company and
      reasonably acceptable to the Trustee and (b) in the case of counsel for
      any Owner Trustee or any Loan Trustee may be such counsel as
<PAGE>   13
                                      -8-


      may be designated by any of them whether or not such counsel is an
      employee of any of them, and who shall be reasonably acceptable to the
      Trustee.

            Other Pass Through Trust Agreements: Means each of the two other
      America West Airlines 1998-1 Pass Through Trust Agreements relating to
      America West Airlines Pass Through Trust, Series 1998-1B-S and America
      West Airlines Pass Through Trust, Series 1998-1C-S, dated the date hereof.

            Other Trustees: Means the trustees under the Other Pass Through
      Trust Agreements, and any successor or other trustee appointed as provided
      therein.

            Other Trusts: Means the America West Airlines Pass Through Trust,
      Series 1998-1B-S and America West Airlines Pass Through Trust, Series
      1998-1C-S, created under the Other Pass Through Trust Agreements.

            Outstanding: When used with respect to Certificates, means, as of
      the date of determination, all Transfer Date Certificates, and all other
      Certificates theretofore authenticated and delivered under this Agreement,
      in each case except:

                         (i) Certificates theretofore canceled by the Registrar
            or delivered to the Trustee or the Registrar for cancellation;

                         (ii) Certificates for which money in the full amount
            required to make the final distribution with respect to such
            Certificates pursuant to Section 11.01 hereof has been theretofore
            deposited with the Trustee in trust for the Holders of such
            Certificates as provided in Section 4.01 pending distribution of
            such money to such Certificateholders pursuant to payment of such
            final distribution; and

                         (iii) Certificates in exchange for or in lieu of which
            other Certificates have been authenticated and delivered pursuant to
            this Agreement.

            Owned Aircraft: Has the meaning specified in the second recital to
      this Agreement.

            Owner Participant: With respect to any Equipment Note relating to a
      Leased Aircraft, means the "Owner Participant" as referred to in the
      Indenture pursuant to which such Equipment Note is issued and any
      permitted successor or assign of such Owner Participant; and Owner
      Participants at any time of determination means all of the Owner
      Participants thus referred to in the Indentures.

            Owner Trustee: With respect to any Equipment Note relating to a
      Leased Aircraft, means the "Owner Trustee", as referred to in the
      Indenture pursuant to which such Equipment Note is issued, not in its
      individual capacity but solely as trustee; and Owner Trustees means all of
      the Owner Trustees party to any of the Indentures.
<PAGE>   14
                                      -9-


            Participation Agreement: Means each Participation Agreement to be
      entered into by the Related Trustee pursuant to the Note Purchase
      Agreement, as the same may be amended, supplemented or otherwise modified
      in accordance with its terms.

            Paying Agent: Means the paying agent maintained and appointed for
      the Certificates pursuant to Section 7.12.

            Permitted Investments: Means obligations of the United States of
      America or agencies or instrumentalities thereof for the payment of which
      the full faith and credit of the United States of America is pledged,
      maturing in not more than 60 days after the date of acquisition thereof or
      such lesser time as is required for the distribution of any Special
      Payments on a Special Distribution Date.

            Person: Means any person, including any individual, corporation,
      limited liability company, partnership, joint venture, association,
      joint-stock company, trust, trustee, unincorporated organization, or
      government or any agency or political subdivision thereof.

            Pool Balance: Means, as of any date, (i) the original aggregate face
      amount of the "Certificates" as defined in the Related Pass Through Trust
      Agreement, less (ii) the aggregate amount of all payments made in respect
      of such Certificates other than payments made in respect of interest or
      premium thereon or reimbursement of any costs or expenses incurred in
      connection therewith less (iii) the aggregate amount of unused Deposits
      distributed as a Final Withdrawal other than payments in respect of
      interest or premium thereon. The Pool Balance as of any Distribution Date
      shall be computed after giving effect to the payment of principal, if any,
      on the Equipment Notes or other Trust Property held in such Trust and the
      distribution thereof to be made on such Distribution Date and the
      distribution of the Final Withdrawal to be made on such Distribution Date.

            Pool Factor: Means, as of any date, the quotient (rounded to the
      seventh decimal place) computed by dividing (i) the Pool Balance as at
      such date by (ii) the original aggregate face amount of the "Certificates"
      as defined in the Related Pass Through Trust Agreement. The Pool Factor as
      of any Distribution Date shall be computed after giving effect to the
      payment of principal, if any, on the Equipment Notes or other Trust
      Property and the distribution thereof to be made on such Distribution Date
      and the distribution of the Final Withdrawal to be made on such
      Distribution Date.

            PTC Event of Default: Means any failure to pay within 10 Business
      Days of the due date thereof: (i) the outstanding Pool Balance on the
      Final Legal Distribution Date or (ii) interest due on the Certificates on
      any Distribution Date (unless the Subordination Agent shall have made an
      Interest Drawing or Drawings (as defined in the Intercreditor Agreement),
      or a withdrawal or withdrawals pursuant to section 3.6(f) of the
      Intercreditor Agreement, with respect thereto in an aggregate amount
      sufficient to pay such interest and shall have distributed such amount to
      the Trustee).

            QIB: Means a qualified institutional buyer as defined in Rule 144A.
<PAGE>   15
                                      -10-


            Record Date: Means (i) for Scheduled Payments to be distributed on
      any Regular Distribution Date, other than the final distribution, the 15th
      day (whether or not a Business Day) preceding such Regular Distribution
      Date, and (ii) for Special Payments to be distributed on any Special
      Distribution Date, other than the final distribution, the 15th day
      (whether or not a Business Day) preceding such Special Distribution Date.

            Register and Registrar: Mean the register maintained and the
      registrar appointed pursuant to Sections 3.04 and 7.12.

            Registration Event: Means the declaration of the effectiveness by
      the SEC of the Exchange Offer Registration Statement or the Shelf
      Registration Statement.

            Registration Rights Agreement: Means the Exchange and Registration
      Rights Agreement dated as of October 6, 1998, among the Initial
      Purchasers, the Related Trustee (and after the Transfer Date, the
      Trustee), the Related Other Trustees (and after the Transfer Date, the
      Other Trustees) and the Company, as amended, supplemented or otherwise
      modified from time to time in accordance with its terms.

            Regular Distribution Date: With respect to distributions of
      Scheduled Payments in respect of the Certificates, means each date
      designated as a Regular Distribution Date in the Certificates issued
      pursuant to this Agreement, until payment of all the Scheduled Payments to
      be made under the Equipment Notes held in the Trust have been made;
      provided, however, that, if any such day shall not be a Business Day, the
      related distribution shall be made on the next succeeding Business Day
      without additional interest.

            Regulation S: Means Regulation S under the Securities Act or any
      successor regulation thereto.

            Regulation S Definitive Certificates: Has the meaning specified in
      Section 3.01(e).

            Regulation S Global Certificates: Has the meaning specified in
      Section 3.01(d).

            Related Other Pass Through Trust Agreements: Means the "Other Pass
      Through Trust Agreements" as defined in the Related Pass Through Trust
      Agreement.

            Related Other Trustee: Means the "Other Trustees" as defined in the
      Related Pass Through Trust Agreement.

            Related Other Trusts: Means the "Other Trusts" as defined in the
      Related Pass Through Trust Agreement.

            Related Pass Through Trust Agreement: Means the Pass Through Trust
      Agreement relating to America West Airlines Pass Through Trust, Series
      1998-1A-O, dated as of the date hereof, between the Company and the
      institution acting as trustee thereunder, as amended, supplemented or
      otherwise modified from time to time in accordance with its terms.
<PAGE>   16
                                      -11-


            Related Trust: Means the America West Pass Through Trust, Series
      1998-1A-O, formed under the Related Pass Through Trust Agreement.

            Related Trustee:  Means the trustee under the Related Pass
      Through Trust Agreement.

            Responsible Officer: With respect to the Trustee, any Loan Trustee
      and any Owner Trustee, means any officer in the Corporate Trust Office of
      the Trustee, Loan Trustee or Owner Trustee or any other officer
      customarily performing functions similar to those performed by the persons
      who at the time shall be such officers, respectively, or to whom any
      corporate trust matter is referred because of his knowledge of and
      familiarity with a particular subject.

            Restricted Definitive Certificates: Has the meaning specified in
      Section 3.01(e).

            Restricted Global Certificate: Has the meaning specified in Section
      3.01(c).

            Restricted Legend: Has the meaning specified in Section 3.02.

            Restricted Period: Has the meaning specified in Section 3.01(d).

            Rule 144A: Means Rule 144A under the Securities Act and any
      successor rule thereto.

            Scheduled Payment: With respect to any Equipment Note, means (i) any
      payment of principal or interest on such Equipment Note (other than any
      such payment which is not in fact received by the Subordination Agent
      within five days of the date on which such payment is scheduled to be
      made) due from the obligor thereon or (ii) any payment of interest on the
      Certificates with funds drawn under any Liquidity Facility, which payment
      represents the installment of principal at the stated maturity of such
      installment of principal on such Equipment Note, the payment of regularly
      scheduled interest accrued on the unpaid principal amount of such
      Equipment Note, or both; provided that any payment of principal, premium,
      if any, or interest resulting from the redemption or purchase of any
      Equipment Note shall not constitute a Scheduled Payment.

            SEC: Means the Securities and Exchange Commission, as from time to
      time constituted or created under the United States Securities Exchange
      Act of 1934, as amended, or, if at any time after the execution of this
      instrument such Commission is not existing and performing the duties now
      assigned to it under the Trust Indenture Act, then the body performing
      such duties on such date.

            Securities Act: Means the United States Securities Act of 1933, as
      amended from time to time, or any successor thereto.

            Shelf Registration Statement: Means the shelf registration statement
      which may be required to be filed by the Company with the SEC pursuant to
      any Registration Rights Agreement, other than an Exchange Offer
      Registration Statement.
<PAGE>   17
                                      -12-


            Special Distribution Date: Means each date on which a Special
      Payment is to be distributed as specified in this Agreement; provided,
      however, that, if any such day shall not be a Business Day, the related
      distribution shall be made on the next succeeding Business Day without
      additional interest.

            Special Redemption Premium: Means the premium payable by the Company
      in respect of the Final Withdrawal pursuant to the Note Purchase
      Agreement.

            Special Payment: Means any payment (other than a Scheduled Payment)
      in respect of, or any proceeds of, any Equipment Note or Trust Indenture
      Estate (as defined in each Indenture) or Special Redemption Premium.

            Special Payments Account:  Means the account or accounts created
      and maintained pursuant to Section 4.01(b).

            Subordination Agent: Has the meaning specified in the Intercreditor
      Agreement.

            Substitute Aircraft: Has the meaning specified in the Note Purchase
      Agreement.

            Tax: Means all license, recording, documentary, registration and
      other similar fees and all taxes, levies, imposts, duties, charges,
      assessments or withholdings of any nature whatsoever imposed by any Taxing
      Authority, together with any penalties, additions to tax, fines or
      interest thereon or additions thereto.

            Taxing Authority: Means any federal, state or local government or
      other taxing authority in the United States, any foreign government or any
      political subdivision or taxing authority thereof, any international
      taxing authority or any territory or possession of the United States or
      any taxing authority thereof.

            Transfer Date: Means the moment of execution and delivery of the
      Assignment and Assumption Agreement by each of the parties thereto.

            Transfer Date Certificates: Has the meaning specified in the
      definition of "Certificates".

            Trust: Means the trust created by this Agreement, the estate of
      which consists of the Trust Property.

            Trust Indenture Act: Means the United States Trust Indenture Act of
      1939, as amended from time to time, or any successor thereto.

            Trust Property: Means (i) the Equipment Notes held as the property
      of the Trust and, subject to the Intercreditor Agreement, all monies at
      any time paid thereon and all monies due and to become due thereunder,
      (ii) funds from time to time deposited in the Certificate Account and the
      Special Payments Account and, subject to the Intercreditor Agreement, any
      proceeds from the sale by the Trustee pursuant to Article VI hereof of any
      Equipment Note and (iii) all rights of the Trust and the Trustee, on
      behalf of the
<PAGE>   18
                                      -13-


      Trust, under the Intercreditor Agreement, the Escrow Agreement, the Note
      Purchase Agreement and the Liquidity Facilities, including, without
      limitation, all rights to receive certain payments thereunder, and all
      monies paid to the Trustee on behalf of the Trust pursuant to the
      Intercreditor Agreement or the Liquidity Facilities, provided, that rights
      with respect to the Deposits or under the Escrow Agreement will not
      constitute Trust Property.

            Trustee: Means Wilmington Trust Company, or its successor in
      interest, and any successor or other trustee appointed as provided herein.

            Trustee's Lien: Has the meaning specified in Section 7.17.

            Unindemnified Tax: Means (i) any Tax imposed on the net income, net
      worth or capital, any franchise Tax or similar doing business Tax of the
      Pass Through Trustee (other than any such Tax imposed as a result of the
      Company's assumption of the Equipment Notes pursuant to the purchase of an
      aircraft on an EBO Date or a Material Adverse Tax Event), (ii) any
      withholding Tax imposed by the United States (including, without
      limitation, any withholding Tax imposed by the United States which is
      imposed or increased as a result of the Pass Through Trustee failing to
      deliver to the Company any certificate or document necessary to establish
      that payments under this Agreement are exempt from withholding Tax), and
      (iii) any Avoidable Tax.

            Section 1.02. Compliance Certificates and Opinions. Upon any
application or request (except with respect to matters set forth in Article II)
by the Company, any Owner Trustee or any Loan Trustee to the Trustee to take any
action under any provision of this Agreement, the Company, such Owner Trustee or
such Loan Trustee, as the case may be, shall furnish to the Trustee (i) an
Officer's Certificate stating that, in the opinion of the signers, all
conditions precedent, if any, provided for in this Agreement relating to the
proposed action have been complied with and (ii) an Opinion of Counsel stating
that in the opinion of such counsel all such conditions precedent, if any, have
been complied with, except that in the case of any such application or request
as to which the furnishing of such documents is specifically required by any
provision of this Agreement relating to such particular application or request,
no additional certificate or opinion need be furnished.

            Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Agreement (other than a certificate
provided pursuant to Section 8.04(e)) shall include:

            (1) a statement that each individual signing such certificate or
      opinion has read such covenant or condition and the definitions in this
      Agreement relating thereto;

            (2) a brief statement as to the nature and scope of the examination
      or investigation upon which the statements or opinions contained in such
      certificate or opinion are based;

            (3) a statement that, in the opinion of each such individual, he has
      made such examination or investigation as is necessary to enable him to
      express an informed opinion as to whether or not such covenant or
      condition has been complied with; and
<PAGE>   19
                                      -14-


            (4) a statement as to whether, in the opinion of each such
      individual, such condition or covenant has been complied with.

            Section 1.03. Form of Documents Delivered to Trustee. In any case
where several matters are required to be certified by, or covered by an opinion
of, any specified Person, it is not necessary that all such matters be certified
by, or covered by the opinion of, only one such Person, or that they be so
certified or covered by only one document, but one such Person may certify or
give an opinion with respect to some matters and one or more other such Persons
as to other matters and any such Person may certify or give an opinion as to
such matters in one or several documents.

            Where any Person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Agreement or, in respect of the Certificates, this
Agreement, they may, but need not, be consolidated and form one instrument.

            Section 1.04. Directions of Certificateholders. (a) Any direction,
consent, request, demand, authorization, notice, waiver or other action provided
by this Agreement to be given or taken by Certificateholders (a "Direction") may
be embodied in and evidenced by one or more instruments of substantially similar
tenor signed by such Certificateholders in person or by an agent or proxy duly
appointed in writing; and, except as herein otherwise expressly provided, such
action shall become effective when such instrument or instruments are delivered
to the Trustee and, where it is hereby expressly required pursuant to this
Agreement, to the Company or any Loan Trustee. Proof of execution of any such
instrument or of a writing appointing any such agent or proxy shall be
sufficient for any purpose of this Agreement and conclusive in favor of the
Trustee, the Company and any Loan Trustee, if made in the manner provided in
this Section.

            (b) The fact and date of the execution by any Person of any such
instrument or writing may be proved by the certificate of any notary public or
other officer of any jurisdiction authorized to take acknowledgments of deeds or
administer oaths that the Person executing such instrument acknowledged to him
the execution thereof, or by an affidavit of a witness to such execution sworn
to before any such notary or such other officer and where such execution is by
an officer of a corporation or association or a member of a partnership, on
behalf of such corporation, association or partnership, such certificate or
affidavit shall also constitute sufficient proof of his authority. The fact and
date of the execution of any such instrument or writing, or the authority of the
Person executing the same, may also be proved in any other reasonable manner
which the Trustee deems sufficient.

            (c) In determining whether the Certificateholders of the requisite
Fractional Undivided Interests of Certificates Outstanding have given any
Direction under this Agreement, Certificates owned by the Company or any
Affiliate thereof shall be disregarded and deemed not to be Outstanding for
purposes of any such determination. In determining whether the Trustee shall be
protected in relying upon any such Direction, only Certificates which the
Trustee knows to be so owned shall be so disregarded. Notwithstanding the
foregoing, (i) if any such Person owns 100% of the Certificates Outstanding,
such Certificates shall not be so disregarded, and (ii) if any amount of
Certificates so owned by any such Person have been pledged in good faith, such
<PAGE>   20
                                      -15-


Certificates shall not be disregarded if the pledgee establishes to the
satisfaction of the Trustee the pledgee's right so to act with respect to such
Certificates and that the pledgee is not the Company or any Affiliate thereof.

            (d) For all purposes of this Agreement, all Initial Certificates
constituting Certificates and all Exchange Certificates constituting
Certificates shall vote and take all other actions of Certificateholders
together as one series of Certificates.

            (e) The Company may at its option, by delivery of an Officer's
Certificate to the Trustee, set a record date to determine the
Certificateholders entitled to give any Direction. Notwithstanding Section
316(c) of the Trust Indenture Act, such record date shall be the record date
specified in such Officer's Certificate, which shall be a date not more than 30
days prior to the first solicitation of Certificateholders in connection
therewith. If such a record date is fixed, such Direction may be given before or
after such record date, but only the Certificateholders of record at the close
of business on such record date shall be deemed to be Certificateholders for the
purposes of determining whether Certificateholders of the requisite proportion
of Outstanding Certificates have authorized or agreed or consented to such
Direction, and for that purpose the Outstanding Certificates shall be computed
as of such record date; provided that no such Direction by the
Certificateholders on such record date shall be deemed effective unless it shall
become effective pursuant to the provisions of this Agreement not later than one
year after such record date.

            (f) Any Direction by the Holder of any Certificate shall bind the
Holder of every Certificate issued upon the transfer thereof or in exchange
therefor or in lieu thereof, whether or not notation of such Direction is made
upon such Certificate.

            (g) Except as otherwise provided in Section 1.04(c), Certificates
owned by or pledged to any Person shall have an equal and proportionate benefit
under the provisions of this Agreement, without preference, priority, or
distinction as among all of the Certificates.


                                   ARTICLE II

                          ACQUISITION OF TRUST PROPERTY

            Section 2.01. Acquisition of Trust Property. The Trustee is hereby
irrevocably authorized and directed to execute and deliver the Assignment and
Assumption Agreement on the date specified in Section 11.01 of the Related Pass
Through Trust Agreement, subject only to the satisfaction of the conditions to
such execution set forth in said Section 11.01. This Agreement (except only for
the immediately preceding sentence hereof, which is effective upon execution and
delivery hereof) shall become effective upon the execution and delivery of the
Assignment and Assumption Agreement by the Trustee and the Related Trustee,
automatically and without any further signature or action on the part of the
Company and the Trustee, and shall thereupon constitute the legal, valid and
binding obligation of the parties hereto enforceable against each of the parties
hereto in accordance with its terms. Upon such execution and delivery of the
Assignment and Assumption Agreement, the Related Trust shall be terminated, the
Certificateholders shall receive beneficial interests in the Trust in exchange
for their interests in the Related Trust equal to their respective beneficial
interests in the Related Trust and the
<PAGE>   21
                                      -16-


"Outstanding" (as defined in the Related Pass Through Trust Agreement) pass
through certificates representing fractional undivided interests in the Related
Trust shall be deemed for all purposes of this Agreement and the Related Pass
Through Trust Agreement, without further signature or action of any party or
Certificateholder, to be Certificates representing the same Fractional Undivided
Interests in the Trust and the Trust Property. By acceptance of its Certificate,
each Certificateholder consents to and ratifies such assignment, transfer and
delivery of the trust property of the Related Trust to the Trustee upon the
execution and delivery of the Assignment and Assumption Agreement.

            Section 2.02. Acceptance by Trustee . The Trustee, upon the
execution and delivery of the Assignment and Assumption Agreement, acknowledges
its acceptance of all right, title and interest in and to the Trust Property and
declares that the Trustee holds and will hold such right, title and interest for
the benefit of all then present and future Certificateholders, upon the trusts
herein set forth. Subject to Section 7.14, the Trustee shall take all actions
reasonably necessary to maintain the registration of all such Equipment Notes in
the name of the Subordination Agent. By the acceptance of each Certificate
issued to it under the Related Pass Through Trust Agreement and deemed issued
under this Agreement, each Holder of any such Certificate as grantor of the
Trust thereby joins in the creation and declaration of the Trust.

            Section 2.03. Limitation of Powers . The Trust is constituted solely
for the purpose of making the investment in the Equipment Notes, and, except as
set forth herein, the Trustee shall not be authorized or empowered to acquire
any other investments or engage in any other activities and, in particular, the
Trustee shall not be authorized or empowered to do anything that would cause
such Trust to fail to qualify as a "grantor trust" for federal income tax
purposes (including as subject to this restriction, acquiring any Aircraft (as
defined in the respective Indentures) by bidding such Equipment Notes or
otherwise, or taking any action with respect to any such Aircraft once
acquired).


                                   ARTICLE III

                                THE CERTIFICATES

            Section 3.01. Title, Form, Denomination and Execution of
Certificates. (a) The Initial Certificates constituting Certificates shall be
known as the "6.87% Initial Pass Through Certificates, Series 1998-1A-S" and the
Exchange Certificates constituting Certificates shall be known as the "6.87%
Exchange Pass Through Certificates, Series 1998-1A-S", in each case, of the
Trust. Each Certificate will represent a fractional undivided interest in the
Trust and shall be substantially in the form set forth as Exhibit A to the
Related Pass Through Trust Agreement, with such appropriate insertions,
omissions, substitutions and other variations as are required or permitted by
the Related Pass Through Trust Agreement or this Agreement, as the case may be,
or as the Trustee may deem appropriate to reflect the fact that the Certificates
are being issued hereunder as opposed to the Related Pass Through Trust
Agreement, and may have such letters, numbers or other marks of identification
and such legends or endorsements placed thereon as may be required to comply
with the rules of any securities exchange or as may, consistently herewith, be
determined by the Trustee or the officers executing such Certificates, as
evidenced by the Trustee's or officer's execution of the Certificates (provided
that such letters, numbers or other marks of identification and such legends or
endorsements are in a form acceptable to the
<PAGE>   22
                                      -17-


Company). At the Escrow Agent's request under the Escrow Agreement, the Trustee
shall affix the corresponding Escrow Receipt to any Certificate issued
hereunder. Any transfer or exchange of any Certificate shall also effect a
transfer or exchange of the related Escrow Receipt. Prior to the Final
Withdrawal Date, no transfer or exchange of any Certificate shall be permitted
unless the corresponding Escrow Receipt is attached thereto and also is so
transferred or exchanged. By acceptance of any Certificate to which an Escrow
Receipt is attached, each Holder of such a Certificate acknowledges and accepts
the restrictions on transfer of the Escrow Receipt set forth herein and in the
Escrow Agreement.

            (b) The Initial Certificates shall be issued only in fully
registered form without coupons and only in denominations of $100,000 or
integral multiples of $1,000 in excess thereof, except that one Certificate may
be issued in a different denomination. The Exchange Certificates will be issued
in denominations of $1,000 or integral multiples thereof, except that one
Certificate may be issued in a different denomination. Each Certificate shall be
dated the date of its authentication. The aggregate Fractional Undivided
Interest of Certificates shall not at any time exceed $131,670,000.

            (c) The Initial Certificates offered and sold in reliance on Rule
144A shall be in the form of one or more Global Certificates substantially in
the form of Exhibit A to the Related Pass Through Trust Agreement with such
applicable legends as are provided for in Section 3.02 (each a "Restricted
Global Certificate"). Such Restricted Global Certificates shall be in registered
form and be registered in the name of DTC and deposited with the Trustee, at its
Corporate Trust Office, as custodian for DTC. The aggregate principal amount of
any Restricted Global Certificate may from time to time be increased or
decreased by adjustments made on the records of the Trustee, as custodian for
DTC for such Restricted Global Certificate, as provided in Section 3.06 hereof,
which adjustments shall be conclusive as to the aggregate principal amount of
any such Global Certificate.

            (d) The Initial Certificates offered and sold outside the United
States in reliance on Regulation S shall be in the form of one or more global
Certificates substantially in the form of Exhibit A to the Related Pass Through
Trust Agreement (each a "Regulation S Global Certificate"). Such Regulation S
Global Certificates shall be in registered form and be registered in the name of
DTC and deposited with the Trustee, at its Corporate Trust Office, as custodian
for DTC, for credit initially and during the Restricted Period (hereinafter
defined) to the respective accounts of beneficial owners of such Certificates
(or to such other accounts as they may direct) at Morgan Guaranty Trust Company
of New York, Brussels office, as operator of Euroclear or Cedel. As used herein,
the term "Restricted Period", with respect to the Regulation S Global
Certificates offered and sold in reliance on Regulation S, means the period of
40 consecutive days beginning on and including the later of (i) the day on which
the "Certificates" (as defined in the Related Pass Through Trust Agreement are
first offered to persons other than distributors (as defined in Regulation S) in
reliance on Regulation S and (ii) the date of the closing of the offering under
the Certificate Purchase Agreement. The aggregate principal amount of any
Regulation S Global Certificate may from time to time be increased or decreased
by adjustments made on the records of the Trustee, as custodian for DTC for such
Global Certificate, as provided in Section 3.06 hereof, which adjustments shall
be conclusive as to the aggregate principal amount of any such Global
Certificate. The Restricted
<PAGE>   23
                                      -18-


Global Certificate and Regulation S Global Certificate are sometimes
collectively referred to herein as the "Global Certificates".

            (e) Initial Certificates offered and sold to any Institutional
Accredited Investor which is not a QIB in a transaction exempt from registration
under the Securities Act (and other than as described in Section 3.01(d)) shall
be substantially in the form of Exhibit A to the Related Pass Through Trust
Agreement in definitive, fully registered form without interest coupons with
such applicable legends as are provided for in Section 3.02 (the "Restricted
Definitive Certificates"). Such Certificates issued pursuant to Section 3.05(b)
in exchange for interests in a Regulation S Global Certificate shall be issued
in definitive, fully registered form without interest coupons (the "Regulation S
Definitive Certificates"). The Restricted Definitive Certificates and the
Regulation S Definitive Certificates are sometimes collectively referred to
herein as the "Definitive Certificates".

            (f) The Exchange Certificates exchanged for Initial Certificates
under the Related Trust shall be in the form of one or more global Certificates
substantially in the form of Exhibit A thereto (each, a "Global Exchange
Certificate"). Exchange Certificates issued under this Trust (each, also a
"Global Exchange Certificate") shall be in the form of one or more global
certificates substantially in the form of Exhibit A to the Related Pass Through
Trust Agreement except that (i) the Restricted Legend (hereinafter defined)
shall be omitted and (ii) such Exchange Certificates shall contain such
appropriate insertions, omissions, substitutions and other variations from the
form set forth in Exhibit A to the Related Pass Through Trust Agreement relating
to the nature of the Exchange Certificates or to reflect the fact that the
Certificates are being issued hereunder as opposed to the Related Pass Through
Trust Agreement, as the Responsible Officer of the Trustee executing such
Exchange Certificates on behalf of the Trust may determine, as evidenced by such
officer's execution on behalf of the Trust of such Exchange Certificates. Such
Global Exchange Certificates shall be in registered form and be registered in
the name of DTC and deposited with the Trustee, at its Corporate Trust Office,
as custodian for DTC. The aggregate principal amount of any Global Exchange
Certificate may from time to time be increased or decreased by adjustments made
on the records of the Trustee, as custodian for DTC for such Global Exchange
Certificate, which adjustments shall be conclusive as to the aggregate principal
amount of any such Global Exchange Certificate. Subject to clause (i) and (ii)
of the second sentence of this Section 3.01(f), the terms hereof applicable to
Restricted Global Certificates and/or Global Certificates shall apply to the
Global Exchange Certificates, mutatis mutandis.

            (g) The Definitive Certificates shall be in registered form and
shall be typed, printed, lithographed or engraved or produced by any combination
of these methods or may be produced in any other manner, all as determined by
the officers executing such Certificates, as evidenced by their execution of
such Certificates.

            Section 3.02. Restrictive Legends . All Initial Certificates issued
for resale pursuant to Rule 144A or offered and sold to any Institutional
Accredited Investor which is not a QIB (including any Global Certificate issued
upon registration of transfer, in exchange for or in lieu of such Certificates)
shall be "Restricted Certificates" and shall bear a legend to the following
effect (the "Restricted Legend") unless the Company and the Trustee determine
otherwise consistent with applicable law:
<PAGE>   24
                                      -19-


            THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE U.S. SECURITIES
      ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND ACCORDINGLY, MAY NOT
      BE OFFERED OR SOLD WITHIN THE UNITED STATES OR TO, OR FOR THE ACCOUNT OR
      BENEFIT OF, ANY PERSONS EXCEPT AS SET FORTH IN THE FOLLOWING SENTENCE. BY
      ITS ACQUISITION HEREOF, THE HOLDER (1) REPRESENTS THAT (A) IT IS A
      "QUALIFIED INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A UNDER THE
      SECURITIES ACT), (B) IT IS AN INSTITUTIONAL "ACCREDITED INVESTOR" (AS
      DEFINED IN RULE 501(a)(1), (2), (3) OR (7) OF REGULATION D UNDER THE
      SECURITIES ACT) (AN "INSTITUTIONAL ACCREDITED INVESTOR") OR (C) IT IS NOT
      A U.S. PERSON AND IS ACQUIRING THIS CERTIFICATE IN AN OFFSHORE TRANSACTION
      IN COMPLIANCE WITH REGULATION S UNDER THE SECURITIES ACT; (2) AGREES THAT
      IT WILL NOT WITHIN TWO YEARS AFTER THE LATER OF THE ORIGINAL ISSUANCE OF
      THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS CERTIFICATE WAS HELD BY
      AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY AFFILIATE OF ANY OF SUCH
      PERSONS RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE EXCEPT (A) TO
      AMERICA WEST AIRLINES, INC., (B) TO A QUALIFIED INSTITUTIONAL BUYER IN
      COMPLIANCE WITH RULE 144A UNDER THE SECURITIES ACT, (C) OUTSIDE THE UNITED
      STATES IN AN OFFSHORE TRANSACTION IN COMPLIANCE WITH RULE 904 UNDER THE
      SECURITIES ACT, (D) PURSUANT TO THE EXEMPTION FROM REGISTRATION PROVIDED
      BY RULE 144 UNDER THE SECURITIES ACT (IF AVAILABLE) OR (E) PURSUANT TO AN
      EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT; AND (3) AGREES
      THAT IF IT SHOULD RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE IT WILL
      DELIVER TO EACH PERSON TO WHOM THIS CERTIFICATE IS TRANSFERRED A NOTICE
      SUBSTANTIALLY TO THE EFFECT OF THIS LEGEND. IN CONNECTION WITH ANY
      TRANSFER OF THIS CERTIFICATE WITHIN TWO YEARS AFTER THE LATER OF THE
      ORIGINAL ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS
      CERTIFICATE WAS HELD BY AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY
      AFFILIATE OF ANY OF SUCH PERSONS, THE HOLDER MUST CHECK THE APPROPRIATE
      BOX SET FORTH ON THE REVERSE HEREOF RELATING TO THE MANNER OF SUCH
      TRANSFER AND SUBMIT THIS CERTIFICATE TO THE TRUSTEE. AS USED HEREIN, THE
      TERMS "OFFSHORE TRANSACTION", "UNITED STATES" AND "U.S. PERSON" HAVE THE
      MEANINGS GIVEN TO THEM BY REGULATION S UNDER THE SECURITIES ACT. THE PASS
      THROUGH TRUST AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO
      REFUSE TO REGISTER ANY TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE
      FOREGOING RESTRICTIONS.

            Each Global Certificate shall bear the following legend on the face
      thereof:

            UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE
      OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE
      TRUSTEE OR ITS AGENT FOR
<PAGE>   25
                                      -20-


      REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED
      IN EXCHANGE FOR THIS CERTIFICATE IS REGISTERED IN THE NAME OF CEDE & CO.
      OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF
      DTC (AND ANY PAYMENT HEREON IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY
      AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER,
      PLEDGE OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS
      WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN
      INTEREST HEREIN.

            TRANSFERS OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO TRANSFERS
      IN WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A SUCCESSOR THEREOF OR
      SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL
      CERTIFICATE SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE
      RESTRICTIONS SET FORTH IN SECTIONS 3.05 AND 3.06 OF THE PASS THROUGH TRUST
      AGREEMENT REFERRED TO HEREIN.

            Section 3.03. Authentication of Certificates. (a) No Certificate
shall be entitled to any benefit under this Agreement or be valid or obligatory
for any purpose, unless there appears on such Certificate a certificate of
authentication substantially in the form provided for herein executed by the
Trustee by the manual signature of one of its authorized signatories, and such
certificate upon any Certificate shall be conclusive evidence, and the only
evidence, that such Certificate has been duly authenticated and delivered
hereunder.

            (b) Certificates bearing the manual or facsimile signature of an
individual who was, at the time when such signature was affixed, authorized to
sign on behalf of the Trustee shall be valid and binding obligations of the
Trust notwithstanding that such individual has ceased to be so authorized prior
to the authentication and delivery of such Certificates or did not hold such
office on the date of such Certificates.

            Section 3.04. Transfer and Exchange. The Trustee shall cause to be
kept at the office or agency to be maintained by it in accordance with the
provisions of Section 7.12 a register (the "Register") of the Certificates in
which, subject to such reasonable regulations as it may prescribe, the Trustee
shall provide for the registration of such Certificates and of transfers and
exchanges of such Certificates as herein provided. The Trustee shall initially
be the registrar (the "Registrar") for the purpose of registering such
Certificates and transfers and exchanges of such Certificates as herein
provided. The Company, upon notice to the Trustee, may change the Registrar at
any time.

            All Certificates issued upon any registration of transfer or
exchange of Certificates shall be valid obligations of the Trust, evidencing the
same interest therein, and entitled to the same benefits under this Agreement,
as the Certificates surrendered upon such registration of transfer or exchange.

            A Certificateholder may transfer a Certificate, or request that a
Certificate be exchanged for Certificates in an aggregate Fractional Undivided
Interest equal to the Fractional
<PAGE>   26
                                      -21-


Undivided Interest of such Certificate surrendered for exchange of other
authorized denominations, by surrender of such Certificate to the Trustee with
the form of transfer notice thereon duly completed and executed, and otherwise
complying with the terms of this Agreement, including providing evidence of
compliance with any restrictions on transfer, in form satisfactory to the
Trustee and the Registrar; provided that no exchanges of Initial Certificates
for Exchange Certificates shall occur until an Exchange Offer Registration
Statement shall have been declared effective by the SEC (notice of which shall
be provided to the Trustee by the Company). No such transfer shall be effected
until, and such transferee shall succeed to the rights of a Certificateholder
only upon, final acceptance and registration of the transfer by the Registrar in
the Register. Prior to the registration of any transfer by a Certificateholder
as provided herein, the Trustee shall treat the person in whose name the
Certificate is registered as the owner thereof for all purposes, and the Trustee
shall not be affected by notice to the contrary. Furthermore, DTC shall, by
acceptance of a Global Certificate, agree that transfers of beneficial interests
in such Global Certificate may be effected only through a book-entry system
maintained by DTC (or its agent), and that ownership of a beneficial interest in
the Certificate shall be required to be reflected in book-entry. When
Certificates are presented to the Registrar with a request to register the
transfer thereof or to exchange them for other authorized denominations of a
Certificate in a Fractional Undivided Interest equal to the aggregate Fractional
Undivided Interest of Certificates surrendered for exchange, the Registrar shall
register the transfer or make the exchange as requested if its requirements for
such transactions are met.

            To permit registrations of transfers and exchanges in accordance
with the terms, conditions and restrictions hereof, the Trustee shall execute
and authenticate Certificates at the Registrar's request. No service charge
shall be made to a Certificateholder for any registration of transfer or
exchange of Certificates, but the Trustee shall require payment of a sum
sufficient to cover any tax or governmental charge that may be imposed in
connection with any transfer or exchange of Certificates. All Certificates
surrendered for registration of transfer or exchange shall be canceled and
subsequently destroyed by the Trustee.

            Section 3.05. Book-Entry Provisions for Restricted Global
Certificates and Regulation S Global Certificates. (a) Members of, or
participants in, DTC ("Agent Members") shall have no rights under this Agreement
with respect to any Global Certificate held on their behalf by DTC, or the
Trustee as its custodian, and DTC may be treated by the Trustee and any agent of
the Trustee as the absolute owner of such Global Certificate for all purposes
whatsoever. Notwithstanding the foregoing, nothing herein shall prevent the
Trustee or any agent of the Trustee from giving effect to any written
certification, proxy or other authorization furnished by DTC or shall impair, as
between DTC and its Agent Members, the operation of customary practices
governing the exercise of the rights of a holder of any Certificate. Upon the
issuance of any Global Certificate, the Registrar or its duly appointed agent
shall record DTC as the registered holder of such Global Certificate.

            (b) Transfers of any Global Certificate shall be limited to
transfers of such Restricted Global Certificate or Regulation S Global
Certificate in whole, but not in part, to DTC. Beneficial interests in the
Restricted Global Certificate and any Regulation S Global Certificate may be
transferred in accordance with the rules and procedures of DTC and the
provisions of Section 3.06. Beneficial interests in a Restricted Global
Certificate or a Regulation S Global Certificate shall be (or, under the Related
Pass Through Trust Agreement,
<PAGE>   27
                                      -22-


may have been) delivered to all beneficial owners thereof in the form of
Restricted Definitive Certificates or Regulation S Definitive Certificates, as
the case may be, if (i) DTC notifies the Trustee that it is unwilling or unable
to continue as depositary for such Restricted Global Certificate or Regulation S
Global Certificate, as the case may be, and a successor depositary is not
appointed by the Trustee within 90 days of such notice, and (ii) after the
occurrence and during the continuance of an Event of Default, owners of
beneficial interests in a Global Certificate with Fractional Undivided Interests
aggregating not less than a majority in interest in the Trust advise the
Trustee, the Company and DTC through Agent Members in writing that the
continuation of a book-entry system through DTC or its successor is no longer in
their best interests.

            (c) Any beneficial interest in one of the Global Certificates that
is transferred to a Person who takes delivery in the form of an interest in
another Global Certificate will, upon such transfer, cease to be an interest in
such Global Certificate and become an interest in the other Global Certificate
and, accordingly, will thereafter be subject to all transfer restrictions, if
any, and other procedures applicable to beneficial interests in such other
Global Certificate for as long as it remains such an interest.

            (d) In connection with the transfer of an entire Restricted Global
Certificate or an entire Regulation S Global Certificate to the beneficial
owners thereof pursuant to paragraph (b) of this Section 3.05, such Restricted
Global Certificate or Regulation S Global Certificate, as the case may be, shall
be deemed to be surrendered to the Trustee for cancellation, and the Trustee
shall execute, authenticate and deliver, to each beneficial owner identified by
DTC in exchange for its beneficial interest in such Restricted Global
Certificate or Regulation S Global Certificate, as the case may be, an equal
aggregate principal amount of Restricted Definitive Certificates or Regulation S
Definitive Certificates, as the case may be, of authorized denominations. None
of the Company, the Registrar, the Paying Agent nor the Trustee shall be liable
for any delay in delivery of such instructions and may conclusively rely on, and
shall be protected in relying on, such registration instructions. Upon the
issuance of Definitive Certificates, the Trustee shall recognize the Person in
whose name the Definitive Certificates are registered in the Register as
Certificateholders hereunder. Neither the Company nor the Trustee shall be
liable if the Trustee or the Company is unable to locate a qualified successor
clearing agency.

            (e) Any Definitive Certificate delivered in exchange for an interest
in the Restricted Global Certificate pursuant to paragraph (b) of this Section
3.05 shall, except as otherwise provided by paragraph (e) of Section 3.06, bear
the Restricted Legend.

            (f) Prior to the expiration of the Restricted Period, any Regulation
S Definitive Certificate delivered in exchange for an interest in a Regulation S
Global Certificate pursuant to paragraph (b) of this Section shall bear the
Restricted Legend.

            (g) The registered holder of any Restricted Global Certificate or
Regulation S Global Certificate may grant proxies and otherwise authorize any
Person, including Agent Members and Persons that may hold interests through
Agent Members, to take any action which a Holder is entitled to take under this
Agreement or the Certificates.
<PAGE>   28
                                      -23-


            Section 3.06. Special Transfer Provisions Unless and until (i) an
Initial Certificate is sold under an effective Shelf Registration Statement, or
(ii) an Initial Certificate is exchanged for an Exchange Certificate pursuant to
an effective Exchange Offer Registration Statement, in each case pursuant to the
terms of the Registration Rights Agreement, the following provisions shall apply
to such Initial Certificates:

            (a) Transfers to Non-QIB Institutional Accredited Investors. The
      following provisions shall apply with respect to the registration of any
      proposed transfer of a Certificate to any Institutional Accredited
      Investor which is neither a QIB nor a Non-U.S. Person:

                         (i) The Registrar shall register the transfer of any
            Certificate, whether or not bearing the Restricted Legend, only if
            (x) the requested transfer is at least two years after the later of
            the original issue date of the Certificates and the last date on
            which such Certificate was held by the Company, the Trustee or any
            affiliate of any of such Persons or (y) the proposed transferor is
            an Initial Purchaser who is transferring Certificates purchased
            under the Certificates Purchase Agreement and the proposed
            transferee has delivered to the Registrar a letter substantially in
            the form of Exhibit B hereto and the aggregate principal amount of
            the Certificates being transferred is at least $100,000. Except as
            provided in the foregoing clause (y), the Registrar shall not
            register the transfer of any Certificate to any Institutional
            Accredited Investor which is neither a QIB nor a Non-U.S. Person.

                         (ii) If the proposed transferor is an Agent Member
            holding a beneficial interest in a Restricted Global Certificate,
            upon receipt by the Registrar of (x) the documents, if any, required
            by paragraph (i) and (y) instructions given in accordance with DTC's
            and the Registrar's procedures, the Registrar shall reflect on its
            books and records the date of the transfer and a decrease in the
            principal amount of such Restricted Global Certificate in an amount
            equal to the principal amount of the beneficial interest in such
            Restricted Global Certificate to be transferred, and the Trustee
            shall execute, authenticate and deliver to the transferor or at its
            direction, one or more Restricted Definitive Certificates of like
            tenor and amount.

            (b) Transfers to QIBs. The following provisions shall apply with
      respect to the registration of any proposed transfer of an Initial
      Certificate to a QIB (excluding Non-U.S. Persons):

                         (i) If the Certificate to be transferred consists of
            Restricted Definitive Certificates, or of an interest in any
            Regulation S Global Certificate during the Restricted Period, the
            Registrar shall register the transfer if such transfer is being made
            by a proposed transferor who has checked the box provided for on the
            form of Initial Certificate stating, or has otherwise advised the
            Trustee and the Registrar in writing, that the sale has been made in
            compliance with the provisions of Rule 144A to a transferee who has
            signed the certification provided for on the form of Initial
            Certificate stating, or has otherwise advised the Trustee 
<PAGE>   29
                                      -24-

            and the Registrar in writing, that it is purchasing the Initial
            Certificate for its own account or an account with respect to which
            it exercises sole investment discretion and that it, or the Person
            on whose behalf it is acting with respect to any such account, is a
            QIB within the meaning of Rule 144A, and is aware that the sale to
            it is being made in reliance on Rule 144A and acknowledges that it
            has received such information regarding the Trust and/or the Company
            as it has requested pursuant to Rule 144A or has determined not to
            request such information and that it is aware that the transferor is
            relying upon its foregoing representations in order to claim the
            exemption from registration provided by Rule 144A.

                         (ii) Upon receipt by the Registrar of the documents
            required by clause (i) above and instructions given in accordance
            with DTC's and the Registrar's procedures therefor, the Registrar
            shall reflect on its books and records the date of such transfer and
            an increase in the principal amount of a Restricted Global
            Certificate in an amount equal to the principal amount of the
            Restricted Definitive Certificates or interests in such Regulation S
            Global Certificate, as the case may be, being transferred, and the
            Trustee shall cancel such Definitive Certificates or decrease the
            amount of such Regulation S Global Certificate so transferred.

            (c) Transfers of Interests in the Regulation S Global Certificate or
      Regulation S Definitive Certificates. After the expiration of the
      Restricted Period, the Registrar shall register any transfer of interests
      in any Regulation S Global Certificate or Regulation S Definitive
      Certificates without requiring any additional certification. Until the
      expiration of the Restricted Period, interests in the Regulation S Global
      Certificate may only be held through Agent Members acting for and on
      behalf of Euroclear and Cedel.

            (d) Transfers to Non-U.S. Persons at Any Time. The following
      provisions shall apply with respect to any registration of any transfer of
      an Initial Certificate to a Non-U.S. Person:

                         (i) Prior to the expiration of the Restricted Period,
            the Registrar shall register any proposed transfer of an Initial
            Certificate to a Non-U.S. Person upon receipt of a certificate
            substantially in the form set forth as Exhibit A hereto from the
            proposed transferor.

                         (ii) After the expiration of the Restricted Period, the
            Registrar shall register any proposed transfer to any Non-U.S.
            Person if the Certificate to be transferred is a Restricted
            Definitive Certificate or an interest in a Restricted Global
            Certificate, upon receipt of a certificate substantially in the form
            of Exhibit A from the proposed transferor. The Registrar shall
            promptly send a copy of such certificate to the Company.

                         (iii) Upon receipt by the Registrar of (x) the
            documents, if any, required by clause (ii) and (y) instructions in
            accordance with DTC's and the Registrar's procedures, the Registrar
            shall reflect on its books and records the date of such transfer and
            a decrease in the principal amount of such Restricted Global
<PAGE>   30
                                      -25-


            Certificate in an amount equal to the principal amount of the
            beneficial interest in such Restricted Global Certificate to be
            transferred, and, upon receipt by the Registrar of instructions
            given in accordance with DTC's and the Registrar's procedures, the
            Registrar shall reflect on its books and records the date and an
            increase in the principal amount of the Regulation S Global
            Certificate in an amount equal to the principal amount of the
            Restricted Definitive Certificate or the Restricted Global
            Certificate, as the case may be, to be transferred, and the Trustee
            shall cancel the Definitive Certificate, if any, so transferred or
            decrease the amount of such Restricted Global Certificate.

            (e) Restricted Legend. Upon the transfer, exchange or replacement of
      Certificates not bearing the Restricted Legend, the Registrar shall
      deliver Certificates that do not bear the Restricted Legend. Upon the
      transfer, exchange or replacement of Certificates bearing the Restricted
      Legend, the Registrar shall deliver only Certificates that bear the
      Restricted Legend unless either (i) the circumstances contemplated by
      paragraph (d)(ii) of this Section 3.06 exist or (ii) there is delivered to
      the Registrar an Opinion of Counsel to the effect that neither such legend
      nor the related restrictions on transfer are required in order to maintain
      compliance with the provisions of the Securities Act.

            (f) General. By acceptance of any Certificate bearing the Restricted
      Legend, each Holder of such a Certificate acknowledges the restrictions on
      transfer of such Certificate set forth in this Agreement and agrees that
      it will transfer such Certificate only as provided in this Agreement. The
      Registrar shall not register a transfer of any Certificate unless such
      transfer complies with the restrictions on transfer, if any, of such
      Certificate set forth in this Agreement. In connection with any transfer
      of Certificates, each Certificateholder agrees by its acceptance of the
      Certificates to furnish the Registrar or the Trustee such certifications,
      legal opinions or other information as either of them may reasonably
      require to confirm that such transfer is being made pursuant to an
      exemption from, or a transaction not subject to, the registration
      requirements of the Securities Act and in accordance with the terms and
      provisions of this Article III; provided that the Registrar shall not be
      required to determine the sufficiency of any such certifications, legal
      opinions or other information.

            Until such time as no Certificates remain Outstanding, the Registrar
shall retain copies of all letters, notices and other written communications
received pursuant to Section 3.05 or this Section 3.06. The Trustee, if not the
Registrar at such time, shall have the right to inspect and make copies of all
such letters, notices or other written communications at any reasonable time
upon the giving of reasonable written notice to the Registrar.

            Section 3.07. Mutilated, Destroyed, Lost or Stolen Certificates. If
(a) any mutilated Certificate is surrendered to the Registrar or the Registrar
receives evidence to its satisfaction of the destruction, loss or theft of any
Certificate and (b) there is delivered to the Registrar and the Trustee such
security, indemnity or bond, as may be required by them to save each of them
harmless, then, in the absence of notice to the Registrar or the Trustee that
such destroyed, lost or stolen Certificate has been acquired by a protected
purchaser, and provided that the requirements of Section 8-405 of the Uniform
Commercial Code in effect in any applicable
<PAGE>   31
                                      -26-


jurisdiction are met, the Trustee shall execute, authenticate and deliver, in
exchange for or in lieu of any such mutilated, destroyed, lost or stolen
Certificate, a new Certificate or Certificates, in authorized denominations and
of like Fractional Undivided Interest and bearing a number not contemporaneously
outstanding.

            In connection with the issuance of any new Certificate under this
Section 3.07, the Trustee may require the payment of a sum sufficient to cover
any tax or other governmental charge that may be imposed in relation thereto and
any other expenses (including the fees and expenses of the Trustee and the
Registrar) connected therewith.

            Any duplicate Certificate issued pursuant to this Section 3.07 shall
constitute conclusive evidence of the appropriate Fractional Undivided Interest
in the Trust, as if originally issued, whether or not the lost, stolen or
destroyed Certificate shall be found at any time.

            The provisions of this Section are exclusive and shall preclude (to
the extent lawful) all other rights and remedies with respect to the replacement
or payment of mutilated, destroyed, lost or stolen Certificates.

            Section 3.08. Persons Deemed Owners. Prior to due presentment of a
Certificate for registration of transfer, the Trustee, the Registrar and any
Paying Agent may treat the Person in whose name any Certificate is registered
(as of the day of determination) as the owner of such Certificate for the
purpose of receiving distributions pursuant to Article IV and for all other
purposes whatsoever, and none of the Trustee, the Registrar or any Paying Agent
shall be affected by any notice to the contrary.

            Section 3.09. Cancellation. All Certificates surrendered for payment
or transfer or exchange shall, if surrendered to the Trustee or any agent of the
Trustee other than the Registrar, be delivered to the Registrar for cancellation
and shall promptly be canceled by it. No Certificates shall be authenticated in
lieu of or in exchange for any Certificates canceled as provided in this
Section, except as expressly permitted by this Agreement. All canceled
Certificates held by the Registrar shall be destroyed and a certification of
their destruction delivered to the Trustee.

            Section 3.10. Temporary Certificates. Until definitive Certificates
are ready for delivery, the Trustee shall authenticate temporary Certificates.
Temporary Certificates shall be substantially in the form of definitive
Certificates but may have insertions, substitutions, omissions and other
variations determined to be appropriate by the officers executing the temporary
Certificates, as evidenced by their execution of such temporary Certificates. If
temporary Certificates are issued, the Trustee will cause definitive
Certificates to be prepared without unreasonable delay. After the preparation of
definitive Certificates, the temporary Certificates shall be exchangeable for
definitive Certificates upon surrender of the temporary Certificates at the
office or agency of the Trustee designated for such purpose pursuant to Section
7.12, without charge to the Certificateholder. Upon surrender for cancellation
of any one or more temporary Certificates, the Trustee shall execute,
authenticate and deliver in exchange therefor a like face amount of definitive
Certificates of authorized denominations. Until so exchanged, the temporary
Certificates shall be entitled to the same benefits under this Agreement as
definitive Certificates.
<PAGE>   32
                                      -27-


            Section 3.11. Limitation of Liability for Payments. All payments and
distributions made to Certificateholders in respect of the Certificates shall be
made only from the Trust Property and only to the extent that the Trustee shall
have sufficient income or proceeds from the Trust Property to make such payments
in accordance with the terms of Article IV of this Agreement. Each
Certificateholder, by its acceptance of a Certificate, agrees that it will look
solely to the income and proceeds from the Trust Property for any payment or
distribution due to such Certificateholder pursuant to the terms of this
Agreement and that it will not have any recourse to the Company, the Trustee,
the Loan Trustees, the Liquidity Providers, the Owner Trustees or the Owner
Participants, except as otherwise expressly provided herein or in the
Intercreditor Agreement.

            The Company is a party to this Agreement solely for purposes of
meeting the requirements of the Trust Indenture Act, and therefore shall not
have any right, obligation or liability hereunder (except as otherwise expressly
provided herein).


                                   ARTICLE IV

                          DISTRIBUTIONS; STATEMENTS TO
                               CERTIFICATEHOLDERS

            Section 4.01. Certificate Account and Special Payments Account. (a)
The Trustee shall maintain on behalf of the Certificateholders a Certificate
Account as one or more non-interest-bearing accounts. The Trustee shall hold the
Certificate Account in trust for the benefit of the Certificateholders, and
shall make or permit withdrawals therefrom only as provided in this Agreement.
On each day when a Scheduled Payment is made to the Trustee under the
Intercreditor Agreement, the Trustee upon receipt thereof shall immediately
deposit the aggregate amount of such Scheduled Payment in the Certificate
Account.

            (b) The Trustee shall maintain on behalf of the Certificateholders a
Special Payments Account as one or more accounts, which shall be non-interest
bearing except as provided in Section 4.04. The Trustee shall hold the Special
Payments Account in trust for the benefit of the Certificateholders and shall
make or permit withdrawals therefrom only as provided in this Agreement. On each
day when one or more Special Payments are made to the Trustee under the
Intercreditor Agreement and upon the payment of the Special Redemption Premium
to the Trustee under the Note Purchase Agreement, the Trustee, upon receipt
thereof, shall immediately deposit the aggregate amount of such Special Payments
in the Special Payments Account.

            (c) The Trustee shall cause the Subordination Agent to present to
the related Loan Trustee of each Equipment Note such Equipment Note on the date
of its stated final maturity or, in the case of any Equipment Note which is to
be redeemed in whole pursuant to the related Indenture, on the applicable
redemption date under such Indenture.

            Section 4.02. Distributions from Certificate Account and Special
Payments Account. (a) On each Regular Distribution Date or as soon thereafter as
the Trustee has confirmed receipt of the payment of all or any part of the
Scheduled Payments due on such date, the Trustee shall distribute out of the
Certificate Account the entire amount deposited therein
<PAGE>   33
                                      -28-


pursuant to Section 4.01(a). There shall be so distributed to each
Certificateholder of record on the Record Date with respect to such Regular
Distribution Date (other than as provided in Section 11.01 concerning the final
distribution) by check mailed to such Certificateholder, at the address
appearing in the Register, such Certificateholder's pro rata share (based on the
Fractional Undivided Interest in the Trust held by such Certificateholder) of
the total amount in the Certificate Account, except that, with respect to
Certificates registered on the Record Date in the name of DTC, such distribution
shall be made by wire transfer in immediately available funds to the account
designated by DTC.

            (b) On each Special Distribution Date with respect to any Special
Payment or as soon thereafter as the Trustee has confirmed receipt of any
Special Payments due on the Equipment Notes held in the related Trust or
realized upon the sale of such Equipment Notes or receipt of the Special
Redemption Premium, the Trustee shall distribute out of the Special Payments
Account the entire amount of such Special Payment deposited therein pursuant to
Section 4.01(b). There shall be so distributed to each Certificateholder of
record on the Record Date with respect to such Special Distribution Date (other
than as provided in Section 11.01 concerning the final distribution) by check
mailed to such Certificateholder, at the address appearing in the Register, such
Certificateholder's pro rata share (based on the Fractional Undivided Interest
in the Trust held by such Certificateholder) of the total amount in the Special
Payments Account on account of such Special Payment, except that, with respect
to Certificates registered on the Record Date in the name of DTC, such
distribution shall be made by wire transfer in immediately available funds to
the account designated by DTC.

            (c) The Trustee shall cause notice of each Special Payment to be
mailed to each Certificateholder at his address as it appears in the Register.
In the event of redemption or purchase of Equipment Notes held in the Trust,
such notice shall be mailed not less than 20 days prior to the Special
Distribution Date for the Special Payment resulting from such redemption or
purchase, which Special Distribution Date shall be the date of such redemption
or purchase. In the event of the payment of a Special Redemption Premium by the
Company to the Trustee under the Note Purchase Agreement, such notice shall be
mailed, together with the notice by the Escrow Paying Agent under Section 2.06
of the Escrow Agreement, not less than 20 days prior to the Special Distribution
Date for such amount, which Special Distribution Date shall be the Final
Withdrawal Date. In the case of any other Special Payments, such notice shall be
mailed as soon as practicable after the Trustee has confirmed that it has
received funds for such Special Payment, stating the Special Distribution Date
for such Special Payment which shall occur not less than 20 days after the date
of such notice and as soon as practicable thereafter. Notices mailed by the
Trustee shall set forth:

                         (i) the Special Distribution Date and the Record Date
            therefor (except as otherwise provided in Section 11.01),

                         (ii) the amount of the Special Payment for each $1,000
            face amount Certificate and the amount thereof constituting
            principal, premium, if any, and interest,

                         (iii) the reason for the Special Payment, and
<PAGE>   34
                                      -29-


                         (iv) if the Special Distribution Date is the same date
            as a Regular Distribution Date, the total amount to be received on
            such date for each $1,000 face amount Certificate.

If the amount of (i) premium, if any, payable upon the redemption or purchase of
an Equipment Note or (ii) the Special Redemption Premium, if any, has not been
calculated at the time that the Trustee mails notice of a Special Payment, it
shall be sufficient if the notice sets forth the other amounts to be distributed
and states that any premium received will also be distributed.

            If any redemption of the Equipment Notes held in the Trust is
canceled, the Trustee, as soon as possible after learning thereof, shall cause
notice thereof to be mailed to each Certificateholder at its address as it
appears on the Register.

            Section 4.03. Statements to Certificateholders. (a) On each
Distribution Date, the Trustee will include with each distribution to
Certificateholders of a Scheduled Payment or Special Payment, as the case may
be, a statement setting forth the information provided below (in the case of a
Special Payment, including any Special Redemption Premium, reflecting in part
the information provided by the Escrow Paying Agent under the Escrow Agreement).
Such statement shall set forth (per $1,000 face amount Certificate as to (ii),
(iii), (iv) and (v) below) the following information:

            (i) the aggregate amount of funds distributed on such Distribution
      Date hereunder and under the Escrow Agreement, indicating the amount
      allocable to each source;

            (ii) the amount of such distribution hereunder allocable to
      principal and the amount allocable to premium (including the Special
      Redemption Premium), if any;

            (iii) the amount of such distribution hereunder allocable to
      interest; and

            (iv) the amount of such distribution under the Escrow Agreement
      allocable to interest;

            (v) the amount of such distribution under the Escrow Agreement
      allocable to Deposits; and

            (vi) the Pool Balance and the Pool Factor.

            With respect to the Certificates registered in the name of DTC, on
the Record Date prior to each Distribution Date, the Trustee will request from
DTC a securities position listing setting forth the names of all Agent Members
reflected on DTC's books as holding interests in the Certificates on such Record
Date. On each Distribution Date, the Trustee will mail to each such Agent Member
the statement described above and will make available additional copies as
requested by such Agent Member for forwarding to holders of interests in the
Certificates.

            (b) Within a reasonable period of time after the end of each
calendar year but not later than the latest date permitted by law, the Trustee
shall furnish to each Person who at any time during such calendar year was a
Certificateholder of record a statement containing the sum
<PAGE>   35
                                      -30-


of the amounts determined pursuant to clauses (a)(i), (a)(ii), (a)(iii), (a)(iv)
and (a)(v) above for such calendar year or, in the event such Person was a
Certificateholder of record during a portion of such calendar year, for such
portion of such year, and such other items as are readily available to the
Trustee and which a Certificateholder shall reasonably request as necessary for
the purpose of such Certificateholder's preparation of its federal income tax
returns. Such statement and such other items shall be prepared on the basis of
information supplied to the Trustee by the Agent Members and shall be delivered
by the Trustee to such Agent Members to be available for forwarding by such
Agent Members to the holders of interests in the Certificates in the manner
described in Section 4.03(a).

            (c) Promptly following (i) the Transfer Date, if there has been any
change in the information set forth in clauses (x), (y) and (z) below from that
set forth in page 69 of the Offering Circular, and (ii) any early redemption or
purchase of, or any default in the payment of principal or interest in respect
of, any of the Equipment Notes held in the Trust, or any Final Withdrawal, the
Trustee shall furnish to Certificateholders of record on such date a statement
setting forth (x) the expected Pool Balances for each subsequent Regular
Distribution Dates following the Delivery Period Termination Date, (y) the
related Pool Factors for such Regular Distribution Dates and (z) the expected
principal distribution schedule of the Equipment Notes, in the aggregate, held
as Trust Property at the date of such notice. With respect to the Certificates
registered in the name of DTC, on the Transfer Date, the Trustee will request
from DTC a securities position listing setting forth the names of all Agent
Members reflected on DTC's books as holding interests in the "Certificates" (as
defined in the Related Pass Through Trust Agreement) on the Delivery Period
Termination Date. The Trustee will mail to each such Agent Member the statement
described above and will make available additional copies as requested by such
Agent Member for forwarding to holders of interests in the Certificates.

            Section 4.04. Investment of Special Payment Moneys. Any money
received by the Trustee pursuant to Section 4.01(b) representing a Special
Payment which is not distributed on the date received shall, to the extent
practicable, be invested in Permitted Investments by the Trustee pending
distribution of such Special Payment pursuant to Section 4.02. Any investment
made pursuant to this Section 4.04 shall be in such Permitted Investments having
maturities not later than the date that such moneys are required to be used to
make the payment required under Section 4.02 on the applicable Special
Distribution Date and the Trustee shall hold any such Permitted Investments
until maturity. The Trustee shall have no liability with respect to any
investment made pursuant to this Section 4.04, other than by reason of the
willful misconduct or negligence of the Trustee. All income and earnings from
such investments shall be distributed on such Special Distribution Date as part
of such Special Payment.


                                    ARTICLE V

                                   THE COMPANY

            Section 5.01. Maintenance of Corporate Existence. The Company, at
its own cost and expense, will do or cause to be done all things necessary to
preserve and keep in full force and effect its corporate existence, except as
permitted by Section 5.02.
<PAGE>   36
                                      -31-


            Section 5.02. Consolidation, Merger, Etc. The Company shall not
consolidate with or merge into any other corporation or convey, transfer or
lease substantially all of its assets as an entirety to any Person unless:

            (a) the corporation formed by such consolidation or into which the
      Company is merged or the Person that acquires by conveyance, transfer or
      lease substantially all of the assets of the Company as an entirety shall
      be (i) organized and validly existing under the laws of the United States
      of America or any state thereof or the District of Columbia, (ii) a
      "citizen of the United States" as defined in 49 U.S.C. 40102(a)(15), as
      amended, and (iii) a United States certificated air carrier, if and so
      long as such status is a condition of entitlement to the benefits of
      Section 1110 of the Bankruptcy Reform Act of 1978, as amended (11 U.S.C.
      Section 1110);

            (b) the corporation formed by such consolidation or into which the
      Company is merged or the Person which acquires by conveyance, transfer or
      lease substantially all of the assets of the Company as an entirety shall
      execute and deliver to the Trustee a duly authorized, valid, binding and
      enforceable agreement in form and substance reasonably satisfactory to the
      Trustee containing an assumption by such successor corporation or Person
      of the due and punctual performance and observance of each covenant and
      condition of this Agreement, the Other Pass Through Trust Agreements and
      each Financing Document to be performed or observed by the Company; and

            (c) the Company shall have delivered to the Trustee an Officer's
      Certificate of the Company reasonably satisfactory to the Trustee, stating
      that such consolidation, merger, conveyance, transfer or lease and the
      assumption agreement mentioned in clause (b) above comply with this
      Section 5.02 and that all conditions precedent herein provided for
      relating to such transaction have been complied with.

            Upon any consolidation or merger, or any conveyance, transfer or
lease of substantially all of the assets of the Company as an entirety in
accordance with this Section 5.02, the successor corporation or Person formed by
such consolidation or into which the Company is merged or to which such
conveyance, transfer or lease is made shall succeed to, and be substituted for,
and may exercise every right and power of, the Company under this Agreement with
the same effect as if such successor corporation or Person had been named as the
Company herein. No such conveyance, transfer or lease of substantially all of
the assets of the Company as an entirety shall have the effect of releasing any
successor corporation or Person which shall have become such in the manner
prescribed in this Section 5.02 from its liability in respect of this Agreement
and any Financing Document to which it is a party.


                                   ARTICLE VI

                                     DEFAULT

            Section 6.01. Events of Default. (a) Exercise of Remedies. Upon the
occurrence and during the continuation of any Indenture Default under any
Indenture, the Trustee may, to the extent it is the Controlling Party at such
time (as determined pursuant to the
<PAGE>   37
                                      -32-


Intercreditor Agreement), direct the exercise of remedies as provided in the
Intercreditor Agreement.

            (b) Purchase Rights of Certificateholders. By acceptance of its
Certificate, each Certificateholder agrees that at any time after the occurrence
and during the continuation of a Triggering Event,

            (i) each Class B Certificateholder shall have the right to purchase
      all, but not less than all, of the Certificates upon ten days' written
      notice to the Trustee and each other Class B Certificateholder, provided
      that (A) if prior to the end of such ten-day period any other Class B
      Certificateholder notifies such purchasing Class B Certificateholder that
      such other Class B Certificateholder wants to participate in such
      purchase, then such other Class B Certificateholder may join with the
      purchasing Class B Certificateholder to purchase all, but not less than
      all, of the Certificates pro rata based on the Fractional Undivided
      Interest in the Class B Trust held by each such Class B Certificateholder
      and (B) if prior to the end of such ten-day period any other Class B
      Certificateholder fails to notify the purchasing Class B Certificateholder
      of such other Class B Certificateholder's desire to participate in such a
      purchase, then such other Class B Certificateholder shall lose its right
      to purchase the Certificates pursuant to this Section 6.01(b); and

            (ii) each Class C Certificateholder shall have the right (which
      shall not expire upon any purchase of the Certificates pursuant to clause
      (i) above) to purchase all, but not less than all, of the Certificates,
      the Class B Certificates and the Class C Certificates upon ten days'
      written notice to the Trustee, the Class B Trustee and each other Class C
      Certificateholder, provided that (A) if prior to the end of such ten-day
      period any other Class C Certificateholder notifies such purchasing Class
      C Certificateholder that such other Class C Certificateholder wants to
      participate in such purchase, then such other Class C Certificateholder
      may join with the purchasing Class C Certificateholder to purchase all,
      but not less than all, of the Certificates and the Class B Certificates
      pro rata based on the Fractional Undivided Interest in the Class C Trust,
      taken as a whole, held by each such Class C Certificateholder and (B) if
      prior to the end of such ten day period any other Class C
      Certificateholder fails to notify the purchasing Class C Certificateholder
      of such other Class C Certificateholder's desire to participate in such a
      purchase, then such other Class C Certificateholder shall lose its right
      to purchase the Certificates pursuant to this Section 6.01(b); and

            (iii) each Class D Certificateholder shall have the right (which
      shall not expire upon any purchase of the Certificates pursuant to clause
      (i) or (ii) above) to purchase all, but not less than all, of the
      Certificates, the Class B Certificates and the Class C Certificates upon
      ten days' written notice to the Trustee, the Class B Trustee, the Class C
      Trustee and each other Class D Certificateholder, provided that (A) if
      prior to the end of such ten-day period any other Class D
      Certificateholder notifies such purchasing Class D Certificateholder that
      such other Class D Certificateholder wants to participate in such
      purchase, then such other Class D Certificateholder may join with the
      purchasing Class D Certificateholder to purchase all, but not less than
      all, of the Certificates, the Class B Certificates and the Class C
      Certificates pro rata based on the Fractional Undivided Interest in the
      Class D Trust, taken as a whole, held by each such Class D
<PAGE>   38
                                      -33-


      Certificateholder and (B) if prior to the end of such ten day period any
      other Class D Certificateholder fails to notify the purchasing Class D
      Certificateholder of such other Class D Certificateholder's desire to
      participate in such a purchase, then such other Class D Certificateholder
      shall lose its right to purchase the Certificates pursuant to this Section
      6.01(b).

            The purchase price with respect to the Certificates shall be equal
to the Pool Balance of the Certificates, together with accrued and unpaid
interest thereon to the date of such purchase, without premium, but including
any other amounts then due and payable to the Certificateholders under this
Agreement, the Intercreditor Agreement, the Escrow Agreement or any Financing
Document or on or in respect of the Certificates; provided, however, that (i) if
such purchase occurs after the record date specified in Section 2.03(b) of the
Escrow Agreement relating to the distribution of unused Deposits and accrued and
unpaid interest thereunder, such purchase price shall be reduced by the
aggregate amount of unused deposits and interest to be distributed under the
Escrow Agreement (which deducted amounts shall remain distributable to, and may
be retained by, the Certificateholder as of such Record Date) and (ii) if such
purchase occurs after a Record Date, such purchase price shall be reduced by the
amount to be distributed hereunder on the related Distribution Date (which
deducted amounts shall remain distributable to, and may be retained by, the
Certificateholder as of such Record Date); provided further, that no such
purchase of Certificates shall be effective unless the purchaser(s) shall
certify to the Trustee that contemporaneously with such purchase, such
purchaser(s) is purchasing, pursuant to the terms of this Agreement and the
Other Pass Through Trust Agreements, the Certificates, the Class B Certificates
and the Class C Certificates which are senior to the securities held by such
purchaser(s). Each payment of the purchase price of the Certificates referred to
in the first sentence hereof shall be made to an account or accounts designated
by the Trustee and each such purchase shall be subject to the terms of this
Section 6.01(b). Each Certificateholder agrees by its acceptance of its
Certificate that it will, subject to Section 3.04 hereof, upon payment from such
Class B Certificateholder(s), Class C Certificateholder(s) or Class D
Certificateholder(s), as the case may be, of the purchase price set forth in the
first sentence of this paragraph, forthwith sell, assign, transfer and convey to
the purchaser(s) thereof (without recourse, representation or warranty of any
kind except for its own acts), all of the right, title, interest and obligation
of such Certificateholder in this Agreement, the Escrow Agreement, the Deposit
Agreement, the Intercreditor Agreement, the Liquidity Facility, the Financing
Documents and all Certificates and Escrow Receipts held by such
Certificateholder (excluding all right, title and interest under any of the
foregoing to the extent such right, title or interest is with respect to an
obligation not then due and payable as respects any action or inaction or state
of affairs occurring prior to such sale) and the purchaser shall assume all of
such Certificateholder's obligations under this Agreement, the Escrow Agreement,
the Deposit Agreement, the Intercreditor Agreement, the Liquidity Facility, the
Financing Documents and all such Certificates and Escrow Receipts. The
Certificates will be deemed to be purchased on the date payment of the purchase
price is made notwithstanding the failure of the Certificateholders to deliver
any Certificates (whether in the form of Definitive Certificates or beneficial
interests in Global Certificates) and, upon such a purchase, (i) the only rights
of the Certificateholders will be to deliver the Certificates to the
purchaser(s) and receive the purchase price for such Certificates and (ii) if
the purchaser(s) shall so request, such Certificateholder will comply with all
the provisions of Section 3.04 hereof to enable new Certificates to be issued to
the purchaser in such denominations as it shall request.
<PAGE>   39
                                      -34-


All charges and expenses in connection with the issuance of any such new
Certificates shall be borne by the purchaser thereof.

            As used in this Section 6.01(b), the terms "Class B Certificate",
"Class B Certificateholder", "Class B Trust", "Class B Trustee", "Class C
Certificate", "Class C Certificateholder", "Class C Trust", "Class C Trustee",
"Class D Certificate", and "Class D Trust", shall have the respective meanings
assigned to such terms in the Intercreditor Agreement.

            Section 6.02. Incidents of Sale of Equipment Notes. Upon any sale of
all or any part of the Equipment Notes made either under the power of sale given
under this Agreement or otherwise for the enforcement of this Agreement, the
following shall be applicable:

            (1) Certificateholders and Trustee May Purchase Equipment Notes. Any
      Certificateholder, the Trustee in its individual or any other capacity or
      any other Person may bid for and purchase any of the Equipment Notes, and
      upon compliance with the terms of sale, may hold, retain, possess and
      dispose of such Equipment Notes in their own absolute right without
      further accountability.

            (2) Receipt of Trustee Shall Discharge Purchaser. The receipt of the
      Trustee making such sale shall be a sufficient discharge to any purchaser
      for his purchase money, and, after paying such purchase money and
      receiving such receipt, such purchaser or its personal representative or
      assigns shall not be obliged to see to the application of such purchase
      money, or be in any way answerable for any loss, misapplication or
      non-application thereof.

            (3) Application of Moneys Received upon Sale. Any moneys collected
      by the Trustee upon any sale made either under the power of sale given by
      this Agreement or otherwise for the enforcement of this Agreement shall be
      applied as provided in Section 4.02.

            Section 6.03. Judicial Proceedings Instituted by Trustee; Trustee
May Bring Suit. If there shall be a failure to make payment of the principal of,
premium, if any, or interest on any Equipment Note, or if there shall be any
failure to pay Rent (as defined in the relevant Lease) under any Lease when due
and payable, then the Trustee, in its own name and as trustee of an express
trust, as holder of such Equipment Notes, to the extent permitted by and in
accordance with the terms of the Intercreditor Agreement and the Financing
Documents (subject to the rights of the applicable Owner Trustee or Owner
Participant to cure any such failure to pay principal of, premium, if any, or
interest on any Equipment Note or to pay Rent under any Lease in accordance with
the applicable Indenture), shall be entitled and empowered to institute any
suits, actions or proceedings at law, in equity or otherwise, for the collection
of the sums so due and unpaid on such Equipment Notes or under such Lease and
may prosecute any such claim or proceeding to judgment or final decree with
respect to the whole amount of any such sums so due and unpaid.

            Section 6.04. Control by Certificateholders. Subject to Section 6.03
and the Intercreditor Agreement, the Certificateholders holding Certificates
evidencing Fractional Undivided Interests aggregating not less than a majority
in interest in the Trust shall have the
<PAGE>   40
                                      -35-


right to direct the time, method and place of conducting any proceeding for any
remedy available to the Trustee with respect to the Trust or pursuant to the
terms of the Intercreditor Agreement, or exercising any trust or power conferred
on the Trustee under this Agreement or the Intercreditor Agreement, including
any right of the Trustee as Controlling Party under the Intercreditor Agreement
or as holder of the Equipment Notes, provided that:

            (1) such Direction shall not be in conflict with any rule of law or
      with this Agreement and would not involve the Trustee in personal
      liability or expense,

            (2) the Trustee shall not determine that the action so directed
      would be unjustly prejudicial to the Certificateholders not taking part in
      such Direction, and

            (3) the Trustee may take any other action deemed proper by the
      Trustee which is not inconsistent with such Direction.

            Section 6.05. Waiver of Past Defaults. Subject to the Intercreditor
Agreement, the Certificateholders holding Certificates evidencing Fractional
Undivided Interests aggregating not less than a majority in interest in the
Trust (i) may on behalf of all of the Certificateholders waive any past Event of
Default hereunder and its consequences or (ii) if the Trustee is the Controlling
Party, may direct the Trustee to instruct the applicable Loan Trustee to waive
any past Indenture Default under any Indenture and its consequences, and thereby
annul any Direction given by such Certificateholders or the Trustee to such Loan
Trustee with respect thereto, except a default:

            (1) in the deposit of any Scheduled Payment or Special Payment under
      Section 4.01 or in the distribution of any payment under Section 4.02 on
      the Certificates, or

            (2) in the payment of the principal of (premium, if any) or interest
      on the Equipment Notes, or

            (3) in respect of a covenant or provision hereof which under Article
      IX cannot be modified or amended without the consent of each
      Certificateholder holding an Outstanding Certificate affected thereby.

            Upon any such waiver, such default shall cease to exist with respect
to the Certificates and any Event of Default arising therefrom shall be deemed
to have been cured for every purpose and any direction given by the Trustee on
behalf of the Certificateholders to the relevant Loan Trustee shall be annulled
with respect thereto; but no such waiver shall extend to any subsequent or other
default or Event of Default or impair any right consequent thereon. Upon any
such waiver, the Trustee shall vote the Equipment Notes issued under the
relevant Indenture to waive the corresponding Indenture Default.

            Section 6.06. Right of Certificateholders to Receive Payments Not to
Be Impaired. Anything in this Agreement to the contrary notwithstanding,
including, without limitation, Section 6.07 hereof, but subject to the
Intercreditor Agreement, the right of any Certificateholder to receive
distributions of payments required pursuant to Section 4.02 hereof on the
Certificates when due, or to institute suit for the enforcement of any such
payment on or after
<PAGE>   41
                                      -36-


the applicable Regular Distribution Date or Special Distribution Date, shall not
be impaired or affected without the consent of such Certificateholder.

            Section 6.07. Certificateholders May Not Bring Suit Except Under
Certain Conditions. A Certificateholder shall not have the right to institute
any suit, action or proceeding at law or in equity or otherwise with respect to
this Agreement, for the appointment of a receiver or for the enforcement of any
other remedy under this Agreement, unless:

            (1) such Certificateholder previously shall have given written
      notice to the Trustee of a continuing Event of Default;

            (2) Certificateholders holding Certificates evidencing Fractional
      Undivided Interests aggregating not less than 25% of the Trust shall have
      requested the Trustee in writing to institute such action, suit or
      proceeding and shall have offered to the Trustee indemnity as provided in
      Section 7.03(e);

            (3) the Trustee shall have refused or neglected to institute such an
      action, suit or proceeding for 60 days after receipt of such notice,
      request and offer of indemnity; and

            (4) no direction inconsistent with such written request shall have
      been given to the Trustee during such 60-day period by Certificateholders
      holding Certificates evidencing Fractional Undivided Interests aggregating
      not less than a majority in interest in the Trust.

            It is understood and intended that no one or more of the
Certificateholders shall have any right in any manner whatsoever hereunder or
under the Certificates to (i) surrender, impair, waive, affect, disturb or
prejudice any property in the Trust Property or the lien of any Indenture on any
property subject thereto, or the rights of the Certificateholders or the holders
of the Equipment Notes, (ii) obtain or seek to obtain priority over or
preference with respect to any other such Certificateholder or (iii) enforce any
right under this Agreement, except in the manner herein provided and for the
equal, ratable and common benefit of all the Certificateholders subject to the
provisions of this Agreement.

            Section 6.08. Remedies Cumulative. Every remedy given hereunder to
the Trustee or to any of the Certificateholders shall not be exclusive of any
other remedy or remedies, and every such remedy shall be cumulative and in
addition to every other remedy given hereunder or now or hereafter given by
statute, law, equity or otherwise.


                                   ARTICLE VII

                                   THE TRUSTEE

            Section 7.01. Certain Duties and Responsibilities. (a) Except during
the continuance of an Event of Default, the Trustee undertakes to perform such
duties as are specifically set forth in this Agreement, and no implied covenants
or obligations shall be read into this Agreement against the Trustee.
<PAGE>   42
                                      -37-


            (b) In case an Event of Default has occurred and is continuing, the
Trustee shall exercise such of the rights and powers vested in it by this
Agreement, and use the same degree of care and skill in their exercise, as a
prudent man would exercise or use under the circumstances in the conduct of its
own affairs.

            (c) No provision of this Agreement shall be construed to relieve the
Trustee from liability for its own negligent action, its own negligent failure
to act, or its own willful misconduct, except that

            (1) this Subsection shall not be construed to limit the effect of
      Subsection (a) of this Section; and

            (2) the Trustee shall not be liable for any error of judgment made
      in good faith by a Responsible Officer of the Trustee, unless it shall be
      proved that the Trustee was negligent in ascertaining the pertinent facts.

            (d) Whether or not herein expressly so provided, every provision of
this Trust Agreement relating to the conduct or affecting the liability of or
affording protection to the Trustee shall be subject to the provisions of this
Section.

            Section 7.02. Notice of Defaults. As promptly as practicable after,
and in any event within 90 days after, the occurrence of any default (as such
term is defined below) hereunder, the Trustee shall transmit by mail to the
Company, the Owner Trustees, the Owner Participants, the Loan Trustees and the
Certificateholders in accordance with Section 313(c) of the Trust Indenture Act,
notice of such default hereunder known to the Trustee, unless such default shall
have been cured or waived; provided, however, that, except in the case of a
default on the payment of the principal, premium, if any, or interest on any
Equipment Note held in the Trust, the Trustee shall be protected in withholding
such notice if and so long as the board of directors, the executive committee or
a trust committee of directors and/or Responsible Officers of the Trustee in
good faith determine that the withholding of such notice is in the interests of
the Certificateholders. For the purpose of this Section, the term "default"
means any event that is, or after notice or lapse of time or both would become,
an Event of Default.

            Section 7.03. Certain Rights of Trustee. Subject to the provisions
of Section 315 of the Trust Indenture Act:

            (a) the Trustee may rely and shall be protected in acting or
      refraining from acting in reliance upon any resolution, certificate,
      statement, instrument, opinion, report, notice, request, direction,
      consent, order, bond, debenture or other paper or document believed by it
      to be genuine and to have been signed or presented by the proper party or
      parties;

            (b) any request or direction of the Company mentioned herein shall
      be sufficiently evidenced by a written description of the subject matter
      thereof accompanied by an Officer's Certificate and an Opinion of Counsel
      as provided in Section 1.02 of this Agreement;
<PAGE>   43
                                      -38-


            (c) whenever in the administration of this Agreement the Trustee
      shall deem it desirable that a matter be proved or established prior to
      taking, suffering or omitting any action hereunder, the Trustee (unless
      other evidence be herein specifically prescribed) may, in the absence of
      bad faith on its part, rely upon an Officer's Certificate of the Company,
      any Owner Trustee or any Loan Trustee;

            (d) the Trustee may consult with counsel and the advice of such
      counsel or any Opinion of Counsel shall be full and complete authorization
      and protection in respect of any action taken, suffered or omitted by it
      hereunder in good faith and in reliance thereon;

            (e) the Trustee shall be under no obligation to exercise any of the
      rights or powers vested in it by this Agreement at the Direction of any of
      the Certificateholders pursuant to this Agreement, unless such
      Certificateholders shall have offered to the Trustee reasonable security
      or indemnity against the cost, expenses and liabilities which might be
      incurred by it in compliance with such Direction;

            (f) the Trustee shall not be bound to make any investigation into
      the facts or matters stated in any resolution, certificate, statement,
      instrument, opinion, report, notice, request, direction, consent, order,
      bond, debenture or other paper or document;

            (g) the Trustee may execute any of the trusts or powers under this
      Agreement or perform any duties under this Agreement either directly or by
      or through agents or attorneys, and the Trustee shall not be responsible
      for any misconduct or negligence on the part of any agent or attorney
      appointed with due care by it under this Agreement;

            (h) the Trustee shall not be liable with respect to any action taken
      or omitted to be taken by it in good faith in accordance with the
      Direction of the Certificateholders holding Certificates evidencing
      Fractional Undivided Interests aggregating not less than a majority in
      interest in the Trust relating to the time, method and place of conducting
      any proceeding for any remedy available to the Trustee, or exercising any
      trust or power conferred upon the Trustee, under this Agreement; and

            (i) the Trustee shall not be required to expend or risk its own
      funds in the performance of any of its duties under this Agreement, or in
      the exercise of any of its rights or powers, if it shall have reasonable
      grounds for believing that repayment of such funds or adequate indemnity
      against such risk is not reasonably assured to it.

            Section 7.04. Not Responsible for Recitals or Issuance of
Certificates. The recitals contained herein and in the Certificates, except the
certificates of authentication, shall not be taken as the statements of the
Trustee, and the Trustee assumes no responsibility for their correctness.
Subject to Section 7.15, the Trustee makes no representations as to the validity
or sufficiency of this Agreement, any Equipment Notes, the Intercreditor
Agreement, the Deposit Agreement, the Escrow Agreement, the Certificates or any
other Financing Document, except that the Trustee hereby represents and warrants
that this Agreement has been, and the Intercreditor Agreement, the Registration
Rights Agreement, the Note Purchase Agreement, the Escrow Agreement and each
Certificate will be, executed, authenticated and delivered by one of
<PAGE>   44
                                      -39-


its officers who is duly authorized to execute, authenticate and deliver such
document on its behalf.

            Section 7.05. May Hold Certificates. The Trustee, any Paying Agent,
Registrar or any of their Affiliates or any other agent in their respective
individual or any other capacity may become the owner or pledgee of Certificates
and, subject to Sections 310(b) and 311 of the Trust Indenture Act, if
applicable, may otherwise deal with the Company, the Owner Trustees or the Loan
Trustees with the same rights it would have if it were not Trustee, Paying
Agent, Registrar or such other agent.

            Section 7.06. Money Held in Trust. Money held by the Trustee or the
Paying Agent in trust hereunder need not be segregated from other funds except
to the extent required herein or by law and neither the Trustee nor the Paying
Agent shall have any liability for interest upon any such moneys except as
provided for herein.

            Section 7.07. Compensation and Reimbursement. The Company agrees:

            (1) to pay, or cause to be paid, to the Trustee from time to time
      reasonable compensation for all services rendered by it hereunder as set
      forth in a written fee letter dated the date hereof between the Company
      and the Trustee, which letter is incorporated herein by reference (which
      compensation shall not be limited by any provision of law in regard to the
      compensation of a trustee of an express trust);

            (2) except as otherwise expressly provided herein, to reimburse, or
      cause to be reimbursed, the Trustee upon its request for all reasonable
      out-of-pocket expenses, disbursements and advances incurred or made by the
      Trustee in accordance with any provision of this Agreement (including the
      reasonable compensation and the expenses and disbursements of its agents
      and counsel), except any such expense, disbursement or advance as may be
      attributable to its undertaking its normal administrative functions, or
      its negligence, willful misconduct or bad faith or as may be incurred due
      to the Trustee's breach of its representations and warranties set forth in
      Section 7.15; and

            (3) to indemnify, or cause to be indemnified, the Trustee for, and
      to hold it harmless against, any loss, liability, expense or Tax (other
      than for or with respect to any Unindemnified Tax) incurred without
      negligence, willful misconduct or bad faith, on its part, arising out of
      or in connection with the acceptance or administration of this Trust,
      including the costs and expenses of defending itself against any claim or
      liability in connection with the exercise or performance of any of its
      powers or duties hereunder, except for any such loss, liability or expense
      incurred by reason of the Trustee's breach of its covenants hereunder or
      under any Financing Document to which it is a party or its representations
      and warranties set forth in Section 7.15 or in any other Financing
      Document, the authorization or giving or withholding of any future
      amendments, supplements, waivers or consents with respect hereto or any of
      the Financing Documents, which amendments, supplements, waivers or
      consents are not required pursuant to the terms of the Financing Documents
      and not requested by the Company, any loss of tax benefits, any
      Unindemnified Tax, or increase in tax liability under any tax law whether
      or not the Company is required to indemnify thereof or pursuant to this
      Agreement or any
<PAGE>   45
                                      -40-


      costs associated with overhead or normal administration hereunder or
      any voluntary resignation pursuant to Section 7.09.

            With respect to paragraph (3) above, the Trustee shall notify the
Company promptly of any claim for which it may seek indemnity and the Company
shall make payment on any such claim within 30 days of written demand thereof
(delivered together with supporting documentation). The Company shall defend the
claim and the Trustee shall cooperate in the defense. The Trustee may have
separate counsel with the consent of the Company and the Company will pay the
reasonable fees and expenses of such counsel. The Company need not pay for any
settlement made, in settlement or otherwise, without its consent.

            With respect to any Tax other than an Unindemnified Tax, the Trustee
shall be entitled to reimbursement from, and shall have a lien prior to the
Certificates upon, the Trust Property for any such Tax incurred without
negligence, bad faith or willful misconduct, on its part, arising out of or in
connection with the acceptance or administration of such Trust (other than any
Tax attributable to the Trustee's compensation for serving as such), including
any costs and expenses incurred in contesting the imposition of any such Tax. If
the Trustee reimburses itself from the Trust Property of such Trust for any such
Tax, it will mail a brief report within 30 days setting forth the circumstances
thereof to all Certificateholders as their names and addresses appear in the
Register.

            Section 7.08. Corporate Trustee Required; Eligibility. There shall
at all times be a Trustee hereunder which shall be eligible to act as a trustee
under Section 310(a) of the Trust Indenture Act and shall have a combined
capital and surplus of at least $75,000,000 (or a combined capital and surplus
in excess of $5,000,000 and the obligations of which, whether now in existence
or hereafter incurred, are fully and unconditionally guaranteed by a corporation
organized and doing business under the laws of the United States, any state or
territory thereof or of the District of Columbia and having a combined capital
and surplus of at least $75,000,000). If such corporation publishes reports of
conditions at least annually, pursuant to law or to the requirements of federal,
state, territorial or District of Columbia supervising or examining authority,
then for the purposes of this Section 7.08, the combined capital and surplus of
such corporation shall be deemed to be its combined capital and surplus as set
forth in its most recent report of conditions so published.

            In case at any time the Trustee shall cease to be eligible in
accordance with the provisions of this Section 7.08 to act as Trustee, the
Trustee shall resign immediately as Trustee in the manner and with the effect
specified in Section 7.09.

            Section 7.09. Resignation and Removal; Appointment of Successor. (a)
No resignation or removal of the Trustee and no appointment of a successor
Trustee pursuant to this Article shall become effective until the acceptance of
appointment by the successor Trustee under Section 7.10.

            (b) The Trustee may resign at any time as trustee by giving prior
written notice thereof to the Company, the Authorized Agents, the Owner Trustees
and the Loan Trustees. If an instrument of acceptance by a successor Trustee
shall not have been delivered to the Company, the Authorized Agents, the Owner
Trustees, the Loan Trustees and the Trustee
<PAGE>   46
                                      -41-


within 30 days after the giving of such notice of resignation, the resigning
Trustee may petition any court of competent jurisdiction for the appointment of
a successor Trustee.

            (c) The Trustee may be removed at any time by Direction of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not less than a majority in interest in the Trust
delivered to the Trustee and to the Company, the Owner Trustees and the Loan
Trustees.

            (d) If at any time:

            (1) the Trustee shall fail to comply with Section 310 of the Trust
      Indenture Act, if applicable, after written request therefor by the
      Company or by any Certificateholder who has been a bona fide
      Certificateholder for at least six months; or

            (2) the Trustee shall cease to be eligible under Section 7.08 and
      shall fail to resign after written request therefor by the Company or by
      any such Certificateholder; or

            (3) the Trustee shall become incapable of acting or shall be
      adjudged a bankrupt or insolvent or a receiver of the Trustee or of its
      property shall be appointed or any public officer shall take charge or
      control of the Trustee or of its property or affairs for the purpose of
      rehabilitation, conservation or liquidation;

then, in any case, (i) the Company may remove the Trustee or (ii) any
Certificateholder who has been a bona fide Certificateholder for at least six
months may, on behalf of itself and all others similarly situated, petition any
court of competent jurisdiction for the removal of the Trustee and the
appointment of a successor Trustee.

            (e) If a Responsible Officer of the Trustee shall obtain actual
knowledge of an Avoidable Tax which has been or is likely to be asserted, the
Trustee shall promptly notify the Company and shall, within 30 days of such
notification, resign hereunder unless within such 30-day period the Trustee
shall have received notice that the Company has agreed to pay such tax. The
Company shall promptly appoint a successor Trustee in a jurisdiction where there
are no Avoidable Taxes.

            (f) If the Trustee shall resign, be removed or become incapable of
acting or if a vacancy shall occur in the office of the Trustee for any cause,
the Company shall promptly appoint a successor Trustee. If, within one year
after such resignation, removal or incapability, or other occurrence of such
vacancy, a successor Trustee shall be appointed by Direction of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not less than a majority in interest in the Trust
delivered to the Company, the Owner Trustees, the Loan Trustees and the retiring
Trustee, and the Company approves such appointment, which approval shall not be
unreasonably withheld, then the successor Trustee so appointed shall, forthwith
upon its acceptance of such appointment, become the successor Trustee and
supersede the successor Trustee appointed as provided above. If no successor
Trustee shall have been so appointed as provided above and accepted appointment
in the manner hereinafter provided, any Certificateholder who has been a bona
fide Certificateholder for at least six months may, on behalf of himself and all
others similarly situated, petition any court of competent jurisdiction for the
appointment of a successor Trustee.
<PAGE>   47
                                      -42-


            (g) The successor Trustee shall give notice of the resignation and
removal of the Trustee and appointment of the successor Trustee by mailing
written notice of such event by first-class mail, postage prepaid, to the
Certificateholders as their names and addresses appear in the Register. Each
notice shall include the name of such successor Trustee and the address of its
Corporate Trust Office.

            Section 7.10. Acceptance of Appointment by Successor. Every
successor Trustee appointed hereunder shall execute and deliver to the Company,
the Authorized Agents, the Owner Trustees and the Loan Trustees and to the
retiring Trustee an instrument accepting such appointment, and thereupon the
resignation or removal of the retiring Trustee shall become effective and such
successor Trustee, without any further act, deed or conveyance, shall become
vested with all the rights, powers, trusts and duties of the retiring Trustee;
but, on request of the Company or the successor Trustee, such retiring Trustee
shall execute and deliver an instrument transferring to such successor Trustee
all such rights, powers and trusts of the retiring Trustee and shall duly
assign, transfer and deliver to such successor Trustee all Trust Property held
by such retiring Trustee hereunder, subject nevertheless to its lien, if any,
provided for in Section 7.07. Upon request of any such successor Trustee, the
Company, the retiring Trustee and such successor Trustee shall execute and
deliver any and all instruments containing such provisions as shall be necessary
or desirable to transfer and confirm to, and for more fully and certainly
vesting in, such successor Trustee all such rights, powers and trusts.

            No institution shall accept its appointment as a Trustee hereunder
unless at the time of such acceptance such institution shall be qualified and
eligible under this Article VII.

            Section 7.11. Merger, Conversion, Consolidation or Succession to
Business. Any corporation into which the Trustee may be merged or converted or
with which it may be consolidated, or any corporation resulting from any merger,
conversion or consolidation to which the Trustee shall be a party, or any
corporation succeeding to all or substantially all of the corporate trust
business of the Trustee, shall be the successor of the Trustee hereunder,
provided such corporation shall be otherwise qualified and eligible under this
Article VII, without the execution or filing of any paper or any further act on
the part of any of the parties hereto. In case any Certificates shall have been
executed or authenticated, but not delivered, by the Trustee then in office, any
successor by merger, conversion or consolidation to such authenticating Trustee
may adopt such execution or authentication and deliver the Certificates so
executed or authenticated with the same effect as if such successor Trustee had
itself executed or authenticated such Certificates.

            Section 7.12. Maintenance of Agencies. (a) There shall at all times
be maintained an office or agency in the location set forth in Section 12.03
where Certificates may be presented or surrendered for registration of transfer
or for exchange, and for payment thereof and where notices and demands to or
upon the Trustee in respect of such certificates or this Agreement may be
served; provided, however, that, if it shall be necessary that the Trustee
maintain an office or agency in another location (e.g., the Certificates shall
be represented by Definitive Certificates and shall be listed on a national
securities exchange), the Trustee will make all reasonable efforts to establish
such an office or agency. Written notice of the location of each such other
office or agency and of any change of location thereof shall be given by the
Trustee to the Company, the Owner Trustees, the Loan Trustees (in the case of
any Owner
<PAGE>   48
                                      -43-


Trustee or Loan Trustee, at its address specified in the Financing Documents or
such other address as may be notified to the Trustee) and the
Certificateholders. In the event that no such office or agency shall be
maintained or no such notice of location or of change of location shall be
given, presentations and demands may be made and notices may be served at the
Corporate Trust Office of the Trustee.

            (b) There shall at all times be a Registrar and a Paying Agent
hereunder with respect to the Certificates. Each such Authorized Agent shall be
a bank or trust company, shall be a corporation organized and doing business
under the laws of the United States or any state, with a combined capital and
surplus of at least $75,000,000, or, if the Trustee shall be acting as the
Registrar or Paying Agent hereunder, a corporation having a combined capital and
surplus in excess of $5,000,000, the obligations of which are guaranteed by a
corporation organized and doing business under the laws of the United States or
any state, with a combined capital and surplus of at least $75,000,000, and
shall be authorized under such laws to exercise corporate trust powers, subject
to supervision by Federal or state authorities. The Trustee shall initially be
the Paying Agent and, as provided in Section 3.04, Registrar hereunder with
respect to the Certificates. Each Registrar shall furnish to the Trustee, at
stated intervals of not more than six months, and at such other times as the
Trustee may request in writing, a copy of the Register maintained by such
Registrar.

            (c) Any corporation into which any Authorized Agent may be merged or
converted or with which it may be consolidated, or any corporation resulting
from any merger, consolidation or conversion to which any Authorized Agent shall
be a party, or any corporation succeeding to the corporate trust business of any
Authorized Agent, shall be the successor of such Authorized Agent hereunder, if
such successor corporation is otherwise eligible under this Section, without the
execution or filing of any paper or any further act on the part of the parties
hereto or such Authorized Agent or such successor corporation.

            (d) Any Authorized Agent may at any time resign by giving written
notice of resignation to the Trustee, the Company, the Owner Trustees and the
Loan Trustees. The Company may, and at the request of the Trustee shall, at any
time terminate the agency of any Authorized Agent by giving written notice of
termination to such Authorized Agent and to the Trustee. Upon the resignation or
termination of an Authorized Agent or in case at any time any such Authorized
Agent shall cease to be eligible under this Section (when, in either case, no
other Authorized Agent performing the functions of such Authorized Agent shall
have been appointed), the Company shall promptly appoint one or more qualified
successor Authorized Agents, reasonably satisfactory to the Trustee, to perform
the functions of the Authorized Agent which has resigned or whose agency has
been terminated or who shall have ceased to be eligible under this Section. The
Company shall give written notice of any such appointment made by it to the
Trustee, the Owner Trustees and the Loan Trustees; and in each case the Trustee
shall mail notice of such appointment to all Certificateholders as their names
and addresses appear on the Register.

            (e) The Company agrees to pay, or cause to be paid, from time to
time to each Authorized Agent reasonable compensation for its services and to
reimburse it for its reasonable expenses as set forth in the letter agreement
referred to in Section 7.07 hereof.
<PAGE>   49
                                      -44-


            Section 7.13. Money for Certificate Payments to Be Held in Trust.
All moneys deposited with any Paying Agent for the purpose of any payment on
Certificates shall be deposited and held in trust for the benefit of the
Certificateholders entitled to such payment, subject to the provisions of this
Section. Moneys so deposited and held in trust shall constitute a separate trust
fund for the benefit of the Certificateholders with respect to which such money
was deposited.

            The Trustee may at any time, for the purpose of obtaining the
satisfaction and discharge of this Agreement or for any other purpose, direct
any Paying Agent to pay to the Trustee all sums held in trust by such Paying
Agent, such sums to be held by the Trustee upon the same trusts as those upon
which such sums were held by such Paying Agent; and, upon such payment by any
Paying Agent to the Trustee, such Paying Agent shall be released from all
further liability with respect to such money.

            Section 7.14. Registration of Equipment Notes in Name of
Subordination Agent. The Trustee agrees that all Equipment Notes to be purchased
by the Trust shall be issued in the name of the Subordination Agent or its
nominee and held by the Subordination Agent in trust for the benefit of the
Certificateholders, or, if not so held, the Subordination Agent or its nominee
shall be reflected as the owner of such Equipment Notes in the register of the
issuer of such Equipment Notes.

            Section 7.15. Representations and Warranties of Trustee. The Trustee
hereby represents and warrants on the Transfer Date that:

            (a) the Trustee is a Delaware banking corporation organized and
      validly existing in good standing under the laws of the State of Delaware;

            (b) the Trustee has full power, authority and legal right to receive
      the Trust Property assigned by the Related Trustee, assume the obligations
      under, and perform, the Assignment and Assumption Agreement, this
      Agreement, the Intercreditor Agreement, the Registration Rights Agreement,
      the Escrow Agreement, the Note Purchase Agreement and the Financing
      Documents to which it is a party and has taken all necessary action to
      authorize such receipt, assumption and performance by it of the Assignment
      and Assumption Agreement, this Agreement, the Intercreditor Agreement, the
      Registration Rights Agreement, the Escrow Agreement, the Note Purchase
      Agreement and the Financing Documents to which it is a party;

            (c) the receipt of the Trust Property under the Assignment and
      Assumption Agreement and the performance by the Trustee of the Assignment
      and Assumption Agreement, this Agreement, the Intercreditor Agreement, the
      Registration Rights Agreement, the Escrow Agreement, the Note Purchase
      Agreement and the Financing Documents to which it is a party (i) will not
      violate any provision of United States federal law or the law of the state
      of the United States where it is located governing the banking and trust
      powers of the Trustee or any order, writ, judgment, or decree of any
      court, arbitrator or governmental authority applicable to the Trustee or
      any of its assets, (ii) will not violate any provision of the articles of
      association or by-laws of the Trustee, or (iii) will not violate any
      provision of, or constitute, with or without notice or lapse of time, a
<PAGE>   50
                                      -45-


      default under, or result in the creation or imposition of any lien on any
      properties included in the Trust Property pursuant to the provisions of
      any mortgage, indenture, contract, agreement or other undertaking to which
      it is a party, which violation, default or lien could reasonably be
      expected to have an adverse effect on the Trustee's performance or ability
      to perform its duties hereunder or thereunder or on the transactions
      contemplated herein or therein;

            (d) the receipt of the Trust Property under the Assignment and
      Assumption Agreement and the performance by the Trustee of the Assignment
      and Assumption Agreement, this Agreement, the Intercreditor Agreement, the
      Registration Rights Agreement, the Escrow Agreement, the Note Purchase
      Agreement, and the Financing Documents to which it is a party will not
      require the authorization, consent, or approval of, the giving of notice
      to, the filing or registration with, or the taking of any other action in
      respect of, any governmental authority or agency of the United States or
      the state of the United States where it is located regulating the banking
      and corporate trust activities of the Trustee; and

            (e) the Assignment and Assumption Agreement has been duly executed
      and delivered by the Trustee and this Agreement, the Assignment and
      Assumption Agreement, the Intercreditor Agreement, the Registration Rights
      Agreement, the Escrow Agreement, the Note Purchase Agreement, and the
      Financing Documents to which it is a party constitute the legal, valid,
      and binding agreements of the Trustee, enforceable against it in
      accordance with their respective terms, provided that enforceability may
      be limited by (i) applicable bankruptcy, insolvency, reorganization,
      moratorium or similar laws affecting the rights of creditors generally and
      (ii) general principles of equity, regardless of whether applied in a
      proceeding in equity or at law.

            Section 7.16. Withholding Taxes, Information Reporting. The Trustee,
as trustee of the grantor trust created by this Agreement, shall exclude and
withhold from each distribution of principal, premium, if any, and interest and
other amounts due under this Agreement or under the Certificates any and all
withholding taxes applicable thereto as required by law. The Trustee agrees to
act as such withholding agent and, in connection therewith, whenever any present
or future taxes or similar charges are required to be withheld with respect to
any amounts payable in respect of the Certificates, to withhold such amounts and
timely pay the same to the appropriate authority in the name of and on behalf of
the Certificateholders, that it will file any necessary withholding tax returns
or statements when due, and that, as promptly as possible after the payment
thereof, it will deliver to each such Certificateholder appropriate
documentation showing the payment thereof, together with such additional
documentary evidence as such Certificateholders may reasonably request from time
to time. The Trustee agrees to file any other information reports as it may be
required to file under United States law. Each Certificateholder or Investor
that is not a United States person within the meaning of section 7701(a)(30) of
the Internal Revenue Code, as amended, by its acceptance of a Certificate or a
beneficial interest therein, agrees to indemnify and hold harmless the Trust and
the Trustee from and against any improper failure to withhold taxes from amounts
payable to it or for its benefit, other than an improper failure attributable to
the gross negligence or willful misconduct of the Trustee.
<PAGE>   51
                                      -46-


            Section 7.17. Trustee's Liens. The Trustee in its individual
capacity agrees that it will at its own cost and expense promptly take any
action as may be necessary to duly discharge and satisfy in full any mortgage,
pledge, lien, charge, encumbrance, security interest or claim ("Trustee's
Liens") on or with respect to the Trust Property which is attributable to the
Trustee either (i) in its individual capacity and which is unrelated to the
transactions contemplated by this Agreement, the Intercreditor Agreement, the
Note Purchase Agreement or the Financing Documents, or (ii) as Trustee hereunder
or in its individual capacity and which arises out of acts or omissions on the
part of the Trustee which are not contemplated by this Agreement.

            Section 7.18. Preferential Collection of Claims. The Trustee shall
comply with Section 311(a) of the Trust Indenture Act, excluding any creditor
relationship listed in Section 311(b) of the Trust Indenture Act. If the Trustee
shall resign or be removed as Trustee, it shall be subject to Section 311(a) of
the Trust Indenture Act to the extent provided therein.


                                  ARTICLE VIII

                CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE

            Section 8.01. The Company to Furnish Trustee with Names and
Addresses of Certificateholders. The Company will furnish to the Trustee within
15 days after each Record Date with respect to a Scheduled Payment, and at such
other times as the Trustee may request in writing within 30 days after receipt
by the Company of any such request, a list, in such form as the Trustee may
reasonably require, of all information in the possession or control of the
Company as to the names and addresses of the Certificateholders, in each case as
of a date not more than 15 days prior to the time such list is furnished;
provided, however, that so long as the Trustee is the sole Registrar, no such
list need be furnished; and provided further, however, that no such list need be
furnished for so long as a copy of the Register is being furnished to the
Trustee pursuant to Section 7.12.

            Section 8.02. Preservation of Information; Communications to
Certificateholders. The Trustee shall preserve, in as current a form as is
reasonably practicable, the names and addresses of Certificateholders contained
in the most recent list furnished to the Trustee as provided in Section 7.12 or
Section 8.01, as the case may be, and the names and addresses of
Certificateholders received by the Trustee in its capacity as Registrar, if so
acting. The Trustee may destroy any list furnished to it as provided in Section
7.12 or Section 8.01, as the case may be, upon receipt of a new list so
furnished.

            Section 8.03. Reports by Trustee. Within 60 days after May 15 of
each year commencing with the first full year following the date hereof, the
Trustee shall transmit to the Certificateholders, as provided in Section 313(c)
of the Trust Indenture Act, a brief report dated as of such May 15, if required
by Section 313(a) of the Trust Indenture Act.

            Section 8.04. Reports by the Company. The Company shall:

            (a) file with the Trustee, within 30 days after the Company is
      required to file the same with the SEC, copies of the annual reports and
      of the information, documents
<PAGE>   52
                                      -47-


      and other reports (or copies of such portions of any of the foregoing as
      the SEC may from time to time by rules and regulations prescribe) which
      the Company is required to file with the SEC pursuant to section 13 or
      section 15(d) of the Securities Exchange Act of 1934, as amended; or, if
      the Company is not required to file information, documents or reports
      pursuant to either of such sections, then to file with the Trustee and the
      SEC, in accordance with rules and regulations prescribed by the SEC, such
      of the supplementary and periodic information, documents and reports which
      may be required pursuant to section 13 of the Securities Exchange Act of
      1934, as amended, in respect of a security listed and registered on a
      national securities exchange as may be prescribed in such rules and
      regulations;

            (b) during any period, prior to the consummation of the Exchange
      Offer and during which the Shelf Registration Statement is not in effect,
      in which the Company is not subject to Section 13(a), 13(c) or 15(d) under
      the Securities Exchange Act of 1934, make available to any Holder of the
      Certificates in connection with any sale thereof and any prospective
      purchaser of the Certificates from such Holder, in each case upon request,
      the information specified in, and meeting the requirements of, Rule
      144A(d)(4) under the Securities Act but only for so long as any of the
      Certificates remain outstanding and are "restricted securities" within the
      meaning of Rule 144(a)(3) under the Securities Act and, in any event, only
      until the second anniversary of the Issuance Date;

            (c) file with the Trustee and the SEC, in accordance with the rules
      and regulations prescribed by the SEC, such additional information,
      documents and reports with respect to compliance by the Company with the
      conditions and covenants provided for in this Agreement, as may be
      required by such rules and regulations, including, in the case of annual
      reports, if required by such rules and regulations, certificates or
      opinions of independent public accountants, conforming to the requirements
      of Section 1.02;

            (d) transmit to all Certificateholders, in the manner and to the
      extent provided in Section 313(c) of the Trust Indenture Act such
      summaries of any information, documents and reports required to be filed
      by the Company pursuant to subsections (a) and (c) of this Section 8.04 as
      may be required by rules and regulations prescribed by the SEC; and

            (e) furnish to the Trustee, not less often than annually, a brief
      certificate from the principal executive officer, principal financial
      officer, any Vice President (or more senior ranking officer) or the
      principal accounting officer as to his or her knowledge of the Company's
      compliance with all conditions and covenants under this Agreement (it
      being understood that for purposes of this paragraph (e), such compliance
      shall be determined without regard to any period of grace or requirement
      of notice provided under this Agreement).
<PAGE>   53
                                      -48-


                                   ARTICLE IX

                             SUPPLEMENTAL AGREEMENTS

            Section 9.01. Supplemental Agreements Without Consent of
Certificateholders. Without the consent of the Certificateholders, the Company
may (but will not be required to), and the Trustee (subject to Section 9.03)
shall, at the Company's request, at any time and from time to time, enter into
one or more agreements supplemental hereto or, if applicable, to the
Intercreditor Agreement, the Escrow Agreement, the Note Purchase Agreement, the
Deposit Agreement, the Registration Rights Agreement or any Liquidity Facility
in form satisfactory to the Trustee, for any of the following purposes:

            (1) to evidence the succession of another corporation to the Company
      and the assumption by any such successor of the covenants of the Company
      herein contained or of the Company's obligations under the Note Purchase
      Agreement, the Registration Rights Agreement or any Liquidity Facility; or

            (2) to add to the covenants of the Company for the benefit of the
      Certificateholders, or to surrender any right or power conferred upon the
      Company in this Agreement, the Note Purchase Agreement, the Registration
      Rights Agreement or any Liquidity Facility; or

            (3) to correct or supplement any provision in this Agreement, the
      Intercreditor Agreement, the Escrow Agreement, the Deposit Agreement, the
      Note Purchase Agreement, the Registration Rights Agreement or any
      Liquidity Facility which may be defective or inconsistent with any other
      provision herein or therein or to cure any ambiguity or correct any
      mistake or to modify any other provision with respect to matters or
      questions arising under this Agreement, the Escrow Agreement, the Deposit
      Agreement, the Note Purchase Agreement, the Intercreditor Agreement, the
      Registration Rights Agreement or any Liquidity Facility, provided that any
      such action shall not materially adversely affect the interests of the
      Certificateholders; or

            (4) to comply with any requirement of the SEC, any applicable law,
      rules or regulations of any exchange or quotation system on which the
      Certificates are listed, any regulatory body or the Registration Rights
      Agreement to effectuate the Exchange Offer; or

            (5) to modify, eliminate or add to the provisions of this Agreement
      to such extent as shall be necessary to continue the qualification of this
      Agreement (including any supplemental agreement) under the Trust Indenture
      Act or under any similar Federal statute hereafter enacted, and to add to
      this Agreement such other provisions as may be expressly permitted by the
      Trust Indenture Act, excluding, however, the provisions referred to in
      Section 316(a)(2) of the Trust Indenture Act as in effect at the date as
      of which this instrument was executed or any corresponding provision in
      any similar Federal statute hereafter enacted; or
<PAGE>   54
                                      -49-


            (6) to evidence and provide for the acceptance of appointment under
      this Agreement by the Trustee of a successor Trustee and to add to or
      change any of the provisions of this Agreement as shall be necessary to
      provide for or facilitate the administration of the Trust, pursuant to the
      requirements of Section 7.10; or

            (7) to provide the information required under Section 7.12 and
      Section 12.03 as to the Trustee; or

            (8) to modify or eliminate provisions relating to the transfer or
      exchange of Exchange Certificates or the Initial Certificates upon
      consummation of the Exchange Offer (as defined in the Registration Rights
      Agreement) or effectiveness of the Shelf Registration Statement or the
      Exchange Offer Registration Statement;

provided, however, that no such supplemental agreement shall adversely affect
the status of any Trust as a grantor trust under Subpart E, Part I of Subchapter
J of Chapter 1 of Subtitle A of the Internal Revenue Code of 1986, as amended,
for U.S. federal income tax purposes.

            Section 9.02. Supplemental Agreements with Consent of
Certificateholders. With the consent of the Certificateholders holding
Certificates (including consents obtained in connection with a tender offer or
exchange offer for the Certificates) evidencing Fractional Undivided Interests
aggregating not less than a majority in interest in the Trust, by Direction of
said Certificateholders delivered to the Company and the Trustee, the Company
may (with the consent of the Owner Trustees, if any, which consent shall not be
unreasonably withheld), and the Trustee (subject to Section 9.03) shall, enter
into an agreement or agreements for the purpose of adding any provisions to or
changing in any manner or eliminating any of the provisions of this Agreement,
the Intercreditor Agreement, any Liquidity Facility, the Registration Rights
Agreement, the Escrow Agreement, the Deposit Agreement or the Note Purchase
Agreement to the extent applicable to such Certificateholders or of modifying in
any manner the rights and obligations of such Certificateholders under this
Agreement, the Intercreditor Agreement, any Liquidity Facility, the Registration
Rights Agreement, the Escrow Agreement, the Deposit Agreement or the Note
Purchase Agreement; provided, however, that no such agreement shall, without the
consent of the Certificateholder of each Outstanding Certificate affected
thereby:

            (1) reduce in any manner the amount of, or delay the timing of, any
      receipt by the Trustee (or, with respect to the Deposits, the
      Certificateholders) of payments on the Equipment Notes held in the Trust
      or on the Deposits or distributions that are required to be made herein on
      any Certificate, or change any date of payment on any Certificate, or
      change the place of payment where, or the coin or currency in which, any
      Certificate is payable, or impair the right to institute suit for the
      enforcement of any such payment or distribution on or after the Regular
      Distribution Date or Special Distribution Date applicable thereto; or

            (2) permit the disposition of any Equipment Note included in the
      Trust Property except as permitted by this Agreement, or otherwise deprive
      such Certificateholder of the benefit of the ownership of the Equipment
      Notes in the Trust; or
<PAGE>   55
                                      -50-


            (3) reduce the specified percentage of the aggregate Fractional
      Undivided Interests of the Trust which is required for any such
      supplemental agreement, or reduce such specified percentage required for
      any waiver of compliance with certain provisions of this Agreement or
      certain defaults hereunder and their consequences provided for in this
      Agreement; or

            (4) waive, amend or modify Section 2.4, 3.2 or 3.3 of the
      Intercreditor Agreement in a manner adverse to the Certificateholders; or

            (5) modify any of the provisions of this Section 9.02 or Section
      6.05, except to increase any such percentage or to provide that certain
      other provisions of this Agreement cannot be modified or waived without
      the consent of the Certificateholder of each Certificate affected thereby;
      or

            (6) adversely affect the status of any Trust as a grantor trust
      under Subpart E, Part I of Subchapter J of Chapter 1 of Subtitle A of the
      Internal Revenue Code of 1986, as amended, for U.S. federal income tax
      purposes.

            It shall not be necessary for any Direction of Certificateholders
under this Section to approve the particular form of any proposed supplemental
agreement, but it shall be sufficient if such Direction shall approve the
substance thereof.

            Section 9.03. Documents Affecting Immunity or Indemnity. If in the
opinion of the Trustee any document required to be executed by it pursuant to
the terms of Section 9.01 or 9.02 affects any interest, right, duty, immunity or
indemnity in favor of the Trustee under this Agreement, the Trustee may in its
discretion decline to execute such document.

            Section 9.04. Execution of Supplemental Agreements. In executing, or
accepting the additional trusts created by, any agreement permitted by this
Article or the modifications thereby of the trusts created by this Agreement,
the Trustee shall be entitled to receive, and shall be fully protected in
relying upon, an Opinion of Counsel stating that the execution of such
supplemental agreement is authorized or permitted by this Agreement.

            Section 9.05. Effect of Supplemental Agreements. Upon the execution
of any agreement supplemental to this Agreement under this Article, this
Agreement shall be modified in accordance therewith, and such supplemental
agreement shall form a part of this Agreement for all purposes; and every Holder
of a Certificate theretofore or thereafter authenticated and delivered hereunder
shall be bound thereby.

            Section 9.06. Conformity with Trust Indenture Act. Every
supplemental agreement executed pursuant to this Article shall conform to the
requirements of the Trust Indenture Act as then in effect.

            Section 9.07. Reference in Certificates to Supplemental Agreements.
Certificates authenticated and delivered after the execution of any supplemental
agreement pursuant to this Article may bear a notation in form approved by the
Trustee as to any matter provided for in such supplemental agreement; and, in
such case, suitable notation may be made upon Outstanding Certificates after
proper presentation and demand.
<PAGE>   56
                                      -51-


                                    ARTICLE X

                AMENDMENTS TO INDENTURES AND FINANCING DOCUMENTS

            Section 10.01. Amendments and Supplements to Indentures and
Financing Documents. In the event that the Trustee, as holder (or beneficial
owner through the Subordination Agent) of any Equipment Note in trust for the
benefit of the Certificateholders or as Controlling Party under the
Intercreditor Agreement, receives (directly or indirectly through the
Subordination Agent) a request for a consent to any amendment, modification,
waiver or supplement under any Indenture, any other Financing Document, any
Equipment Note or any other related document, the Trustee shall forthwith send a
notice of such proposed amendment, modification, waiver or supplement to each
Certificateholder registered on the Register as of the date of such notice. The
Trustee shall request from the Certificateholders a Direction as to (a) whether
or not to take or refrain from taking (or direct the Subordination Agent to take
or refrain from taking) any action which a holder of such Equipment Note has the
option to direct, (b) whether or not to give or execute (or direct the
Subordination Agent to give or execute) any waivers, consents, amendments,
modifications or supplements as a holder of such Equipment Note or a Controlling
Party and (c) how to vote (or direct the Subordination Agent to vote) any
Equipment Note if a vote has been called for with respect thereto. Provided such
a request for Certificateholder Direction shall have been made, in directing any
action or casting any vote or giving any consent as the holder of any Equipment
Note (or in directing the Subordination Agent in any of the foregoing), (i)
other than as Controlling Party, the Trustee shall vote for or give consent to
any such action with respect to such Equipment Note in the same proportion as
that of (A) the aggregate face amounts of all Certificates actually voted in
favor of or for giving consent to such action by such Direction of
Certificateholders to (B) the aggregate face amount of all Outstanding
Certificates and (ii) as Controlling Party, the Trustee shall vote as directed
in such Certificateholder Direction by the Certificateholders evidencing a
Fractional Undivided Interest aggregating not less than a majority in interest
in the Trust. For purposes of the immediately preceding sentence, a Certificate
shall have been "actually voted" if the Holder of such Certificate has delivered
to the Trustee an instrument evidencing such Holder's consent to such Direction
prior to two Business Days before the Trustee directs such action or casts such
vote or gives such consent. Notwithstanding the foregoing, but subject to
Section 6.04 and the Intercreditor Agreement, the Trustee may, in its own
discretion and at its own direction, consent and notify the relevant Loan
Trustee of such consent (or direct the Subordination Agent to consent and notify
the Loan Trustee of such consent) to any amendment, modification, waiver or
supplement under the relevant Indenture, any other Financing Document, any
Equipment Note or any other related document, if an Event of Default hereunder
shall have occurred and be continuing, or if such amendment, modification,
waiver or supplement will not materially adversely affect the interests of the
Certificateholders.


                                   ARTICLE XI

                              TERMINATION OF TRUST

            Section 11.01. Termination of the Trust. The respective obligations
and responsibilities of the Company and the Trustee with respect to the Trust
shall terminate upon
<PAGE>   57
                                      -52-


the distribution to all Holders of Certificates and the Trustee of all amounts
required to be distributed to them pursuant to this Agreement and the
disposition of all property held as part of the Trust Property; provided,
however, that in no event shall the Trust continue beyond one hundred ten (110)
years following the date of the earliest execution of this Trust Agreement.

            Notice of any termination, specifying the Distribution Date upon
which the Certificateholders may surrender their Certificates to the Trustee for
payment of the final Distribution Date and cancellation, shall be mailed
promptly by the Trustee to Certificateholders not earlier than the 60th day and
not later than the 20th day next preceding such final Distribution Date
specifying (A) the Distribution Date upon which the proposed final payment of
the Certificates will be made upon presentation and surrender of Certificates at
the office or agency of the Trustee therein specified, (B) the amount of any
such proposed final payment, and (C) that the Record Date otherwise applicable
to such Distribution Date is not applicable, payments being made only upon
presentation and surrender of the Certificates at the office or agency of the
Trustee therein specified. The Trustee shall give such notice to the Registrar
at the time such notice is given to Certificateholders. Upon presentation and
surrender of the Certificates in accordance with such notice, the Trustee shall
cause to be distributed to Certificateholders such final payments.

            In the event that all of the Certificateholders shall not surrender
their Certificates for cancellation within six months after the date specified
in the above-mentioned written notice, the Trustee shall give a second written
notice to the remaining Certificateholders to surrender their Certificates for
cancellation and receive the final distribution with respect thereto. No
additional interest shall accrue on the Certificates after the Distribution Date
specified in the first written notice. In the event that any money held by the
Trustee for the payment of distributions on the Certificates shall remain
unclaimed for two years (or such lesser time as the Trustee shall be satisfied,
after sixty days' notice from the Company, is one month prior to the escheat
period provided under applicable law) after the final distribution date with
respect thereto, the Trustee shall pay to each Loan Trustee the appropriate
amount of money relating to such Loan Trustee and shall give written notice
thereof to the related Owner Trustees, the Owner Participants and the Company.


                                   ARTICLE XII

                            MISCELLANEOUS PROVISIONS

            Section 12.01. Limitation on Rights of Certificateholders. The death
or incapacity of any Certificateholder shall not operate to terminate this
Agreement or the Trust, nor entitle such Certificateholder's legal
representatives or heirs to claim an accounting or to take any action or
commence any proceeding in any court for a partition or winding up of the Trust,
nor otherwise affect the rights, obligations, and liabilities of the parties
hereto or any of them.

            Section 12.02. Certificates Nonassessable and Fully Paid. Except as
set forth in the last sentence of this Section 12.02, Certificateholders shall
not be personally liable for obligations of the Trust, the Fractional Undivided
Interests represented by the Certificates shall be nonassessable for any losses
or expenses of the Trust or for any reason whatsoever, and Certificates, upon
authentication thereof by the Trustee pursuant to Section 3.03, are and shall be
<PAGE>   58
                                      -53-


deemed fully paid. No Certificateholder shall have any right (except as
expressly provided herein) to vote or in any manner otherwise control the
operation and management of the Trust Property, the Trust, or the obligations of
the parties hereto, nor shall anything set forth herein, or contained in the
terms of the Certificates, be construed so as to constitute the
Certificateholders from time to time as partners or members of an association.
Neither the existence of the Trust nor any provision herein is intended to or
shall limit the liability the Certificateholders would otherwise incur if the
Certificateholders owned Trust Property as co-owners, or incurred any
obligations of the Trust, directly rather than through the Trust.

            Section 12.03. Notices. (a) Unless otherwise specifically provided
herein, all notices required under the terms and provisions of this Agreement
shall be in English and in writing, and any such notice may be given by United
States mail, courier service or telecopy, and any such notice shall be effective
when received or, if made, given, furnished or filed by facsimile or
telecommunication transmission, when received unless received outside of
business hours, in which case on the next open of business on a Business Day,

            if to the Company, to:

                  America West Airlines, Inc.
                  4000 East Sky Harbor Boulevard
                  Phoenix, Arizona  85043

                  Attention: Vice President-
                             Treasurer
                  Facsimile: (602) 693-5886


            if to the Trustee, to:

                  Wilmington Trust Company
                  Rodney Square North
                  1100 North Market Street
                  Wilmington, Delaware  19890-0001

                  Attention: Corporate Trust Department
                  Facsimile: (302) 651-8882
                  Telephone: (302) 651-8584

            (b) The Company or the Trustee, by notice to the other, may
designate additional or different addresses for subsequent notices or
communications.

            (c) Any notice or communication to Certificateholders shall be
mailed by first-class mail to the addresses for Certificateholders shown on the
Register kept by the Registrar. Failure so to mail a notice or communication or
any defect in such notice or communication shall not affect its sufficiency with
respect to other Certificateholders.
<PAGE>   59
                                      -54-


            (d) If a notice or communication is mailed in the manner provided
above within the time prescribed, it is conclusively presumed to have been duly
given, whether or not the addressee receives it.

            (e) If the Company mails a notice or communication to the
Certificateholders, it shall mail a copy to the Trustee and to the Paying Agent
at the same time.

            (f) Notwithstanding the foregoing, all communications or notices to
the Trustee shall be deemed to be given only when received by a Responsible
Officer of the Trustee.

            (g) The Trustee shall promptly furnish the Company with a copy of
any demand, notice or written communication received by the Trustee hereunder
from any Certificateholder, Owner Trustee or Loan Trustee.

            Section 12.04. Governing Law. THIS AGREEMENT HAS BEEN DELIVERED IN
THE STATE OF NEW YORK AND THIS AGREEMENT AND THE CERTIFICATES SHALL BE GOVERNED
BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK AND THE
OBLIGATIONS, RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER SHALL BE DETERMINED IN
ACCORDANCE WITH SUCH LAWS.

            Section 12.05. Severability of Provisions. If any one or more of the
covenants, agreements, provisions or terms of this Agreement shall be for any
reason whatsoever held invalid, then such covenants, agreements, provisions, or
terms shall be deemed severable from the remaining covenants, agreements,
provisions or terms of this Agreement and shall in no way affect the validity or
enforceability of the other provisions of this Agreement or the Trust, or of the
Certificates or the rights of the Certificateholders thereof.

            Section 12.06. Trust Indenture Act Controls. Upon the occurrence of
any Registration Event, this Agreement shall become subject to the provisions of
the Trust Indenture Act and shall, to the extent applicable, be governed by such
provisions. From and after any Registration Event, if any provision of this
Agreement limits, qualifies or conflicts with another provision which is
required to be included in this Agreement by the Trust Indenture Act, the
required provision shall control.

            Section 12.07. Effect of Headings and Table of Contents. The Article
and Section headings herein and the Table of Contents are for convenience only
and shall not affect the construction hereof.

            Section 12.08. Successors and Assigns. All covenants, agreements,
representations and warranties in this Agreement by the Trustee and the Company
shall bind and, to the extent permitted hereby, shall inure to the benefit of
and be enforceable by their respective successors and assigns, whether so
expressed or not.

            Section 12.09. Benefits of Agreement. Nothing in this Agreement or
in the Certificates, express or implied, shall give to any Person, other than
the parties hereto and their successors hereunder, and the Certificateholders,
any benefit or any legal or equitable right, remedy or claim under this
Agreement.
<PAGE>   60
                                      -55-


            Section 12.10. Legal Holidays. In any case where any Regular
Distribution Date or Special Distribution Date relating to any Certificate shall
not be a Business Day, then (notwithstanding any other provision of this
Agreement) payment need not be made on such date, but may be made on the next
succeeding Business Day with the same force and effect as if made on such
Regular Distribution Date or Special Distribution Date, and no interest shall
accrue during the intervening period.

            Section 12.11. Counterparts. For the purpose of facilitating the
execution of this Agreement and for other purposes, this Agreement may be
executed simultaneously in any number of counterparts, each of which
counterparts shall be deemed to be an original, and all of which counterparts
shall constitute but one and the same instrument.

            Section 12.12. Intention of Parties. The parties hereto intend that
the Trust be classified for U.S. federal income tax purposes as a grantor trust
under Subpart E, Part I of Subchapter J of the Internal Revenue Code of 1986, as
amended, and not as a trust or association taxable as a corporation or as a
partnership. Each Certificateholder and Investor, by its acceptance of its
Certificate or a beneficial interest therein, agrees to treat the Trust as a
grantor trust for all U.S. federal, state and local income tax purposes. The
powers granted and obligations undertaken pursuant to this Agreement shall be so
construed so as to further such intent.
<PAGE>   61
                                      -56-



            IN WITNESS WHEREOF, the parties have caused this Agreement to be
duly executed by their respective officers thereunto duly authorized as of the
day and year first written above.


                                    AMERICA WEST AIRLINES, INC.


                                    By: /s/ W. Douglas Parker
                                       ------------------------------- 
                                          Name: W. Douglas Parker
                                          Title: Sr. Vice President & CFO


                                    WILMINGTON TRUST COMPANY,
                                      as Trustee


                                    By: /s/ Jill K. Morrison
                                       --------------------------------
                                          Name: Jill K. Morrison
                                          Title: Administrative Account
                                                 Manager
<PAGE>   62
                                                                       EXHIBIT A

             FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION WITH
               TRANSFERS OF CERTIFICATES PURSUANT TO REGULATION S

                                                    [date]

Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE 19890-0001

Attention:  Corporate Trust Trustee Administration

      Re:   America West Airlines Pass Through Trust, Series 1998-1A-S (the
            "Trust") America West Airlines Pass Through Certificates, Series
            1998-1A-S (the "Certificates")

Sirs:

            In connection with our proposed sale of $_____ Fractional Undivided
Interest of the Certificates, we confirm that such sale has been effected
pursuant to and in accordance with Regulation S under the Securities Act of
1933, as amended, and, accordingly, we represent that:

            (1) the offer of the Certificates was not made to a person in the
      United States or to or for the account or benefit of a U.S. person;

            (2) either (a) at the time the buy order was originated, the
      transferee was outside the United States or we and any person acting on
      our behalf reasonably believed that the transferee was outside the United
      States or (b) the transaction was executed in, on or through the
      facilities of a designated off-shore securities market and neither we nor
      any person acting on our behalf knows that the transaction has been
      pre-arranged with a buyer in the United States;

            (3) no directed selling efforts have been made in the United States
      in contravention of the requirements of Rule 903(a) or Rule 904(a) of
      Regulation S, as applicable; and

            (4) the transaction is not part of a plan or scheme to evade the
      registration requirements of the Securities Act.

            In addition, if the sale is made during a restricted period and the
provisions of Rule 903(b)(2) or Rule 904(b)(1) of Regulation S are applicable
thereto, we confirm that such sale has been made in accordance with the
applicable provisions of Rule 903(b)(2) or Rule 904(b)(1), as the case may be.

            You and America West Airlines, Inc. are entitled to rely upon this
letter and are irrevocably authorized to produce this letter or a copy hereof to
any interested party in any
<PAGE>   63
                                       A-2


administrative or legal proceedings or official inquiry with respect to the
matters covered hereby. Terms used in this certificate have the meanings set
forth in Regulation S.

                                    Very truly yours,


                                    [Name of Transferor]
<PAGE>   64
                                                                       EXHIBIT B

                FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION
                        WITH TRANSFERS OF CERTIFICATES TO
                   NON-QIB INSTITUTIONAL ACCREDITED INVESTORS

                                                [date]

Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE 19890-0001
Attention:  Corporate Trust Trustee Administration

America West Airlines, Inc.
4000 East Sky Harbor Boulevard
Phoenix, Arizona  85043


                              AMERICA WEST AIRLINES
               PASS THROUGH TRUST, SERIES 1998-1A-S (the "Trust")
                   Pass Through Certificates, Series 1998-1A-S
                              (the "Certificates")


Ladies and Gentlemen:

            In connection with our proposed purchase of U.S. $[_____________]
Fractional Undivided Interest of Certificates, we confirm that:

            1. We understand that any subsequent transfer of the Certificates is
subject to certain restrictions and conditions set forth in the Pass Through
Trust Agreement, dated as of October 6, 1998, between America West Airlines,
Inc. (the "Company") and Wilmington Trust Company (the "Trustee") relating to
the Certificates, and we agree to be bound by, and not to resell, pledge or
otherwise transfer the Certificates except in compliance with, such restrictions
and conditions and the Securities Act of 1933, as amended (the "Securities
Act").

            2. We are purchasing Certificates having an aggregate principal
amount of not less than $100,000 and each account (if any) for which we are
purchasing Certificates is purchasing Certificates having an aggregate principal
amount of not less than $100,000.

            3. We understand that the Certificates have not been registered
under the Securities Act, that the Certificates are being sold to us in a
transaction that is exempt from the registration requirements of the Securities
Act and that the Certificates may not be offered or resold except as permitted
in the following sentence. We agree, on our own behalf and on behalf of any
accounts for which we are acting as hereinafter stated, that, if we should sell
any Certificates within three years after the later of the original issuance of
such Certificate and the last date on which such Certificate is owned by the
Company, the Trustee or any affiliate of any
<PAGE>   65
                                       B-2


of such persons, we will do so only (A) to the Company, (B) in accordance with
Rule 144A under the Securities Act to a "qualified institutional buyer" (as
defined therein), (C) outside the United States in accordance with Rule 904 of
Regulation S under the Securities Act, (D) pursuant to the exemption from
registration provided by Rule 144 under the Securities Act or (E) pursuant to an
effective registration statement under the Securities Act, and we further agree
to provide to any person purchasing any of the Certificates from us a notice
advising such purchaser that resales of the Certificates are restricted as
stated herein.

            4. We understand that, on any proposed resale of any Certificates,
we will be required to furnish to the Company and the Trustee such
certifications, legal opinions and other information as the Trustee may
reasonably require to confirm that the proposed sale complies with the foregoing
restrictions. We further understand that the Certificates purchased by us will
bear a legend to the foregoing effect.

            5. We are an institutional "accredited investor" (as defined in Rule
501(a)(1), (2), (3) or (7) of Regulation D under the Securities Act) and have
such knowledge and experience in financial and business matters as to be capable
of evaluating the merits and risks of our investment in the Certificates, and we
and any accounts for which we are acting are each able to bear the economic risk
of our or their investments.

            6. We are acquiring the Certificates purchased by us for our own
account or for one or more accounts (each of which is an institutional
"accredited investor") as to each of which we exercise sole investment
discretion and not with a view to any distribution of the Certificates, subject,
nevertheless to the understanding that the disposition of our property shall at
all times be and remain within our control.

            You are entitled to rely upon this letter and are irrevocably
authorized to produce this letter or a copy thereof to any interested party in
any administrative or legal proceedings or official inquiry with respect to the
matters covered hereby.

                                    Very truly yours,


                                    By:_____________________________
                                        Name:
                                        Title:

<PAGE>   1
                                                                     Exhibit 4.6





                          PASS THROUGH TRUST AGREEMENT

                           Dated as of October 6, 1998

                                     between

                           AMERICA WEST AIRLINES, INC.

                                       and

                            WILMINGTON TRUST COMPANY,

                                   as Trustee

           America West Airlines Pass Through Trust, Series 1998-1B-O

            7.12% Initial Pass Through Certificates, Series 1998-1B-O
           7.12% Exchange Pass Through Certificates, Series 1998-1B-O
<PAGE>   2
Reconciliation and tie between America West Airlines Pass Through Trust
Agreement, Series 1998-1B-O dated as of October 6, 1998, and the Trust Indenture
Act of 1939. This reconciliation does not constitute part of the Pass Through
Trust Agreement.

Trust Indenture Act                                       Pass Through Trust
   of 1939 Section                                        Agreement Section
 310(a)(1)                                                   7.08
    (a)(2)                                                   7.08
 312(a)                                                      3.05; 8.01; 8.02
 313(a)                                                      7.06; 8.03
 314(a)                                                      8.04(a),(c) & (d)
    (a)(4)                                                   8.04(e)
    (c)(1)                                                   1.02
    (c)(2)                                                   1.02
    (d)(1)                                                   7.13; 11.01
    (d)(2)                                                   7.13; 11.01
    (d)(3)                                                   2.01
    (e)                                                      1.02
 315(b)                                                      7.02
 316(a)(last sentence)                                       1.04(c)
         (a)(1)(A)                                           6.04
         (a)(1)(B)                                           6.05
         (b)                                                 6.06
         (c)                                                 1.04(e)
 317(a)(1)                                                   6.03
    (b)                                                      7.13
 318(a)                                                     12.06
<PAGE>   3
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
SECTION                                                                                                        PAGE
<S>                                                                                                            <C>
ARTICLE I  DEFINITIONS............................................................................................2
         Section 1.01.     Definitions............................................................................2
         Section 1.02.     Compliance Certificates and Opinions..................................................13
         Section 1.03.     Form of Documents Delivered to Trustee................................................14
         Section 1.04.     Directions of Certificateholders......................................................14

ARTICLE II  ORIGINAL ISSUANCE OF CERTIFICATES; ACQUISITION OF EQUIPMENT NOTES....................................16
         Section 2.01.     Issuance of Certificates; Acquisition of Equipment Notes..............................16
         Section 2.02.     Withdrawal of Deposits................................................................17
         Section 2.03.     Acceptance by Trustee.................................................................17
         Section 2.04.     Limitation of Powers..................................................................17

ARTICLE III  THE CERTIFICATES....................................................................................17
         Section 3.01.     Title, Form, Denomination and Execution of Certificates...............................17
         Section 3.02.     Restrictive Legends...................................................................19
         Section 3.03.     Authentication of Certificates........................................................21
         Section 3.04.     Transfer and Exchange.................................................................21
         Section 3.05.     Book-Entry Provisions for Restricted Global Certificates and Regulation S
                           Global Certificates...................................................................22
         Section 3.06.     Special Transfer Provisions...........................................................24
         Section 3.07.     Mutilated, Destroyed, Lost or Stolen Certificates.....................................27
         Section 3.08.     Persons Deemed Owners.................................................................27
         Section 3.09.     Cancellation..........................................................................27
         Section 3.10.     Temporary Certificates................................................................27
         Section 3.11.     Limitation of Liability for Payments..................................................28
         Section 3.12      ERISA Restrictive Legend..............................................................28

ARTICLE IV  DISTRIBUTIONS; STATEMENTS TO CERTIFICATEHOLDERS......................................................29
         Section 4.01.     Certificate Account and Special Payments Account......................................29
         Section 4.02.     Distributions from Certificate Account and Special Payments Account...................29
         Section 4.03.     Statements to Certificateholders......................................................30
         Section 4.04.     Investment of Special Payment Moneys..................................................32

ARTICLE V  THE COMPANY...........................................................................................32
         Section 5.01.     Maintenance of Corporate Existence....................................................32
         Section 5.02.     Consolidation, Merger, etc............................................................32

ARTICLE VI  DEFAULT..............................................................................................33
         Section 6.01.     Events of Default.....................................................................33
         Section 6.02.     Incidents of Sale of Equipment Notes..................................................35
         Section 6.03.     Judicial Proceedings Instituted by Trustee; Trustee May Bring Suit....................36
</TABLE>
<PAGE>   4
<TABLE>
<CAPTION>
SECTION                                                                                                        PAGE
<S>                                                                                                            <C>
         Section 6.04      Control by Certificateholders.........................................................36
         Section 6.05.     Waiver of Past Defaults...............................................................36
         Section 6.06.     Right of Certificateholders to Receive Payments Not to Be Impaired....................37
         Section 6.07.     Certificateholders May Not Bring Suit Except Under Certain Conditions.................37
         Section 6.08.     Remedies Cumulative...................................................................38

ARTICLE VII  THE TRUSTEE.........................................................................................38
         Section 7.01.     Certain Duties and Responsibilities...................................................38
         Section 7.02.     Notice of Defaults....................................................................39
         Section 7.03.     Certain Rights of Trustee.............................................................39
         Section 7.04.     Not Responsible for Recitals or Issuance of Certificates..............................40
         Section 7.05.     May Hold Certificates.................................................................40
         Section 7.06.     Money Held in Trust...................................................................40
         Section 7.07.     Compensation and Reimbursement........................................................40
         Section 7.08.     Corporate Trustee Required; Eligibility...............................................42
         Section 7.09      Resignation and Removal; Appointment of Successor.....................................42
         Section 7.10.     Acceptance of Appointment by Successor................................................43
         Section 7.11.     Merger, Conversion, Consolidation or Succession to Business...........................44
         Section 7.12.     Maintenance of Agencies...............................................................44
         Section 7.13.     Money for Certificate Payments to Be Held in Trust....................................45
         Section 7.14.     Registration of Equipment Notes in Name of Subordination Agent........................45
         Section 7.15.     Representations and Warranties of Trustee.............................................46
         Section 7.16.     Withholding Taxes, Information Reporting..............................................46
         Section 7.17.     Trustee's Liens.......................................................................47
         Section 7.18.     Preferential Collection of Claims.....................................................47

ARTICLE VIII  CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE...................................................48
         Section 8.01.     The Company to Furnish Trustee with Names and Addresses of Certificateholders.........48
         Section 8.02.     Preservation of Information; Communications to Certificateholders.....................48
         Section 8.03.     Reports by Trustee....................................................................48
         Section 8.04.     Reports by the Company................................................................48

ARTICLE IX  SUPPLEMENTAL AGREEMENTS..............................................................................49
         Section 9.01.     Supplemental Agreements Without Consent of Certificateholders.........................49
         Section 9.02.     Supplemental Agreements with Consent of Certificateholders............................50
         Section 9.03.     Documents Affecting Immunity or Indemnity.............................................52
         Section 9.04.     Execution of Supplemental Agreements..................................................52
         Section 9.05.     Effect of Supplemental Agreements.....................................................52
         Section 9.06.     Conformity with Trust Indenture Act...................................................52
         Section 9.07.     Reference in Certificates to Supplemental Agreements..................................52
</TABLE>


                                       ii
<PAGE>   5
<TABLE>
<CAPTION>
SECTION                                                                                                        PAGE
<S>                                                                                                            <C>
ARTICLE X  AMENDMENTS TO INDENTURES AND FINANCING DOCUMENTS......................................................52
         Section 10.01.    Amendments and Supplements to Indentures and Financing Documents......................52

ARTICLE XI  TERMINATION OF TRUST.................................................................................53
         Section 11.01.    Termination of the Trust..............................................................53

ARTICLE XII  MISCELLANEOUS PROVISIONS............................................................................55
         Section 12.01.    Limitation on Rights of Certificateholders............................................55
         Section 12.02.    Certificates Nonassessable and Fully Paid.............................................56
         Section 12.03.    Notices...............................................................................56
         Section 12.04.    Governing Law.........................................................................57
         Section 12.05.    Severability of Provisions............................................................57
         Section 12.06.    Trust Indenture Act Controls..........................................................57
         Section 12.07.    Effect of Headings and Table of Contents..............................................57
         Section 12.08.    Successors and Assigns................................................................58
         Section 12.09.    Benefits of Agreement.................................................................58
         Section 12.10.    Legal Holidays........................................................................58
         Section 12.11.    Counterparts..........................................................................58
         Section 12.12.    Intention of Parties..................................................................58
</TABLE>

Exhibit A - Form of Certificate
Exhibit B - Form of Certificate to Request Removal of Restricted Legend
Exhibit C - Form of Certificate to be Delivered by an Institutional Accredited
            Investor
Exhibit D - Form of Assignment and Assumption Agreement
Exhibit E - Form of Notice to Withholding Agent


                                      iii
<PAGE>   6
                          PASS THROUGH TRUST AGREEMENT

                  This PASS THROUGH TRUST AGREEMENT, dated as of October 6, 1998
(the "Agreement"), between AMERICA WEST AIRLINES, INC., a Delaware corporation,
and WILMINGTON TRUST COMPANY, as Trustee, is made with respect to the formation
of America West Airlines Pass Through Trust, Series 1998-1B-O and the issuance
of 7.12% America West Airlines Pass Through Trust, Series 1998-1B-O Pass Through
Certificates representing fractional undivided interests in the Trust.

                                   WITNESSETH:

                  WHEREAS, the Company has obtained commitments from AVSA for
the delivery of certain Aircraft;

                  WHEREAS, the Company intends to finance (or refinance) the
acquisition of the Aircraft either (i) through separate leveraged lease
transactions in which the Company will lease such aircraft (collectively, the
"Leased Aircraft") or (ii) through separate secured loan transactions in which
the Company will own such Aircraft (collectively, the "Owned Aircraft");

                  WHEREAS, in the case of each Leased Aircraft, each Owner
Trustee, acting on behalf of the corresponding Owner Participant, will issue
pursuant to an Indenture, on a non-recourse basis, three series (or, subject to
satisfaction of certain preconditions contained in the Note Purchase Agreement,
four) of Equipment Notes in order to finance a portion of its purchase price of
such Leased Aircraft;

                  WHEREAS, in the case of each Owned Aircraft, the Company will
issue pursuant to an Indenture, on a recourse basis, three (or, subject to
satisfaction of certain preconditions contained in the Note Purchase Agreement,
four) series of Equipment Notes to finance a portion of the purchase price of
such Owned Aircraft;

                  WHEREAS, the Trustee, upon execution and delivery of this
Agreement, hereby declares the creation of the Trust for the benefit of the
Certificateholders, and the initial Certificateholders, as the grantors of the
Trust, by their respective acceptances of the Certificates, join in the creation
of this Trust with the Trustee;

                  WHEREAS, all Certificates to be issued by the Trust will
evidence fractional undivided interests in the Trust and will convey no rights,
benefits or interests in respect of any property other than the Trust Property
except for those Certificates to which an Escrow Receipt has been affixed;

                  WHEREAS, the Escrow Agent and the Initial Purchasers have
contemporaneously herewith entered into an Escrow Agreement with the Escrow
Paying Agent pursuant to which the Initial Purchasers have delivered to the
Escrow Agent the proceeds from the sale of the Certificates and have irrevocably
instructed the Escrow Agent to withdraw and pay funds from such proceeds upon
request and proper certification by the Trustee to purchase Equipment Notes;
<PAGE>   7
                                      -2-


                  WHEREAS, the Escrow Agent on behalf of the Certificateholders
has contemporaneously herewith entered into a Deposit Agreement with the
Depositary under which the Deposits referred to therein will be made and from
which it will withdraw funds to allow the Trustee to purchase Equipment Notes
from time to time prior to the Delivery Period Termination Date;

                  WHEREAS, pursuant to the terms and conditions of this
Agreement and the Note Purchase Agreement, upon or following delivery of an
Aircraft, the Trustee on behalf of the Trust, using funds withdrawn under the
Escrow Agreement, may purchase an Equipment Note having the same interest rate
as, and final legal distribution date not later than the final Regular
Distribution Date of, the Certificates issued hereunder and shall hold such
Equipment Note in trust for the benefit of the Certificateholders;

                  WHEREAS, to facilitate the sale of Equipment Notes to, and the
purchase of Equipment Notes by, the Trustee on behalf of the Trust, the Company
has duly authorized the execution and delivery of this Agreement as the
"issuer", as such term is defined in and solely for purposes of the Securities
Act, of the Certificates to be issued pursuant hereto and as the "obligor", as
such term is defined in and solely for purposes of the Trust Indenture Act of
1939, as amended, with respect to all such Certificates and is undertaking to
perform certain administrative and ministerial duties hereunder and is also
undertaking to pay the ongoing fees and expenses of the Trustee;

                  WHEREAS, all of the conditions and requirements necessary to
make this Agreement, when duly executed and delivered, a valid, binding and
legal instrument, enforceable in accordance with its terms and for the purposes
herein expressed, have been done, performed and fulfilled, and the execution and
delivery of this Agreement in the form and with the terms hereof have been in
all respects duly authorized; and

                  WHEREAS, upon issuance of the Exchange Certificates, if any,
or the effectiveness of the Shelf Registration Statement, this Agreement, as
amended or supplemented from time to time, will be subject to the provisions of
the Trust Indenture Act of 1939, and shall, to the extent applicable, be
governed by such provisions;

                  NOW, THEREFORE, in consideration of the mutual agreements
herein contained, and of other good and valuable consideration the receipt and
adequacy of which are hereby acknowledged, the parties hereto agree as follows:

                                    ARTICLE I

                                   DEFINITIONS

                  Section 1.01. Definitions. For all purposes of this Agreement,
except as otherwise expressly provided or unless the context otherwise requires:

                  (1) the terms used in this Agreement, including in the
         recitals to this Agreement, that are defined in this Article have the
         meanings assigned to them in this Article, and include the plural as
         well as the singular;
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                  (2) all other terms used herein which are defined in the Trust
         Indenture Act, either directly or by reference therein, or by the rules
         promulgated under the Trust Indenture Act, have the meanings assigned
         to them therein;

                  (3) all references in this Agreement to designated "Articles",
         "Sections", "Subsections" and other subdivisions are to the designated
         Articles, Sections, Subsections and other subdivisions of this
         Agreement;

                  (4) the words "herein", "hereof" and "hereunder" and other
         words of similar import refer to this Agreement as a whole and not to
         any particular Article, Section, SubSection or other subdivision; and

                  (5) unless the context otherwise requires, whenever the words
         "including", "include" or "includes" are used herein, it shall be
         deemed to be followed by the phrase "without limitation".

                  Affiliate: Means, with respect to any specified Person, any
         other Person directly or indirectly controlling or controlled by or
         under direct or indirect common control with such Person. For the
         purposes of this definition, "control" means the power, directly or
         indirectly, to direct the management and policies of such Person,
         whether through the ownership of voting securities or by contract or
         otherwise, and the terms "controlling" and "controlled" have meanings
         correlative to the foregoing.

                  Agent Members: Has the meaning specified in Section 3.05.

                  Agreement: Has the meaning specified in the initial paragraph
         hereto.

                  Aircraft: Has the meaning specified in the Note Purchase
         Agreement.

                  Aircraft Purchase Agreement: Has the meaning specified in the
         Note Purchase Agreement.

                  Applicable Delivery Date: Has the meaning specified in Section
         2.01(b).

                  Applicable Participation Agreement: Has the meaning specified
         in Section 2.01(b).

                  Assignment and Assumption Agreement: Means the assignment and
         assumption agreement substantially in the form of Exhibit D hereto to
         be executed and delivered in accordance with Section 11.01.

                  Authorized Agent: Means any Paying Agent or Registrar for the
         Certificates.

                  Avoidable Tax: Means a state or local tax (i) upon (w) the
         Trust, (x) the Trust Property, (y) Certificate-holders or (z) the
         Trustee for which the Trustee is entitled to seek reimbursement from
         the Trust Property, and (ii) which would be avoided if the Trustee were
         located in another state, or jurisdiction within a state, within the
         United
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         States. A tax shall not be an Avoidable Tax if the Company or any Owner
         Trustee shall agree to pay, and shall pay, such tax.

                  AVSA: Means AVSA S.A.R.L., an affiliate of Airbus Industrie
         G.I.E.

                  Business Day: Means any day other than a Saturday, a Sunday or
         a day on which commercial banks are required or authorized to close in
         Phoenix, Arizona, New York, New York, Wilmington, Delaware or, so long
         as any Certificate is outstanding, the city and state in which the
         Trustee or any Loan Trustee maintains its Corporate Trust Office or
         receives and disburses funds.

                  Cedel: Means Cedel Bank societe anonyme.

                  Certificate: Means any one of the Initial Certificates or
         Exchange Certificates and any such Certificates issued in exchange
         therefor or replacement thereof pursuant to this Agreement.

                  Certificate Account: Means the account or accounts created and
         maintained pursuant to Section 4.01(a).

                  Certificate Purchase Agreement: Means the Purchase Agreement
         dated September 24, 1998 among the Initial Purchasers and the Company,
         as the same may be amended, supplemented or otherwise modified from
         time to time in accordance with its terms.

                  Certificateholder or Holder: Means the Person in whose name a
         Certificate is registered in the Register.

                  Class D Certificateholder: Means, at any time, any holder of
         one or more pass through certificates issued by the America West
         Airlines Pass Through Trust, Series 1998-1D, if and when established.

                  Company: Means America West Airlines, Inc., a Delaware
         corporation, or its successor in interest pursuant to Section 5.02, or
         (only in the context of provisions hereof, if any, where such reference
         is required for purposes of compliance with the Trust Indenture Act)
         any other "obligor" (within the meaning of the Trust Indenture Act)
         with respect to the Certificates.

                  Controlling Party: Has the meaning specified in the
         Intercreditor Agreement.

                  Corporate Trust Office: With respect to the Trustee or any
         Loan Trustee, means the office of such trustee in the city at which at
         any particular time its corporate trust business shall be principally
         administered.

                  Cut-off Date: Means the earlier of (a) the Delivery Period
         Termination Date and (b) the date on which a Triggering Event occurs.

                  Definitive Certificates: Has the meaning specified in Section
         3.01(e).
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                  Delivery Date: Has the meaning specified in the Note Purchase
         Agreement.

                  Delivery Notice: Has the meaning specified in the Note
         Purchase Agreement.

                  Delivery Period Termination Date: Means the earlier of (a)
         November 30, 1999, or, if the Equipment Notes relating to all of the
         Aircraft (or Substitute Aircraft in lieu thereof) have not been
         purchased by the Trustee and the Other Trustees on or prior to such
         date due to any reason beyond the control of the Company and not
         occasioned by the Company's fault or negligence, January 31, 2000 and
         (b) the date on which Equipment Notes issued with respect to all of the
         Aircraft (or Substitute Aircraft in lieu thereof) have been purchased
         by the Trustee and the Other Trustees in accordance with the Note
         Purchase Agreement.

                  Deposits: Has the meaning specified in the Deposit Agreement.

                  Deposit Agreement: Means the Deposit Agreement dated as of
         October 6, 1998 relating to the Certificates between the Depositary and
         the Escrow Agent, as the same may be amended, supplemented or otherwise
         modified from time to time in accordance with its terms.

                  Depositary: Means ABN AMRO Bank N.V., acting through its
         Chicago branch.
         Direction: Has the meaning specified in Section  1.04(a).
        
                  Distribution Date: Means any Regular Distribution Date or
         Special Distribution Date as the context requires.

                  DTC: Means The Depository Trust Company, its nominees and
         their respective successors.

                  EBO Date: Means the date set forth on Schedule 1 to the Lease
         as the "EBO Date".

                  Equipment Notes: Means the equipment notes issued under the
         Indentures.

                  ERISA: Means the Employee Retirement Income Security Act of
         1974, as amended from time to time, or any successor federal statute.

                  ERISA Legend: Has the meaning specified in Section 3.12.

                  Escrow Agent: Means, initially, Wilmington Trust Company.

                  Escrow Agreement: Means the Escrow and Paying Agent Agreement
         dated as of October 6, 1998 relating to the Certificates, among the
         Escrow Agent, the Escrow Paying Agent, the Trustee and the Initial
         Purchasers, as the same may be amended, supplemented or otherwise
         modified from time to time in accordance with its terms.
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                  Escrow Paying Agent: Means the Person acting as paying agent
         under the Escrow Agreement.

                  Escrow Receipt: Means the receipt substantially in the form
         annexed to the Escrow Agreement representing a fractional undivided
         interest in the funds held in escrow thereunder.

                  Euroclear: Means Morgan Guaranty Trust Company of New York,
         Brussels Office, as operator of the Euroclear System.

                  Event of Default: Means an Indenture Default under any
         Indenture pursuant to which Equipment Notes held by the Trust were
         issued.

                  Exchange Certificates: Means the pass through certificates
         substantially in the form of Exhibit A hereto issued in exchange for
         the Initial Certificates pursuant to the Registration Rights Agreement
         and authenticated hereunder.

                  Exchange Offer: Means the exchange offer which may be made
         pursuant to the Registration Rights Agreement to exchange Initial
         Certificates for Exchange Certificates.

                  Exchange Offer Registration Statement: Means the registration
         statement that, pursuant to the Registration Rights Agreement, is filed
         by the Company with the SEC with respect to the exchange of Initial
         Certificates for Exchange Certificates.

                  Final Legal Distribution Date: Means July 2, 2018.

                  Final Withdrawal: Has the meaning specified in the Escrow
         Agreement.

                  Final Withdrawal Date: Has the meaning specified in the Escrow
         Agreement.

                  Final Withdrawal Notice: Has the meaning specified in Section
         2.02.

                  Financing Documents: With respect to any Equipment Note, means
         (i) the Indenture and the Participation Agreement relating to such
         Equipment Note, and (ii) in the case of any Equipment Note related to a
         Leased Aircraft, the Lease relating to such Leased Aircraft.

                  Fractional Undivided Interest: Means the fractional undivided
         interest in the Trust that is evidenced by a Certificate.

                  Global Certificates: Has the meaning specified in Section
         3.01(d).

                  Global Exchange Certificate: Has the meaning specified in
         Section 3.01(f).

                  Indenture: Means each of the separate trust indentures and
         mortgages relating to the Aircraft, each as specified or described in a
         Delivery Notice delivered pursuant to the Note Purchase Agreement or
         the related Participation Agreement, in each case as the
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                                      -7-


         same may be amended, supplemented or otherwise modified from time to
         time in accordance with its terms.

                  Indenture Default: With respect to any Indenture, means any
         Event of Default (as such term is defined in such Indenture).

                  Initial Certificates: Means the certificates issued and
         authenticated hereunder substantially in the form of Exhibit A hereto
         other than the Exchange Certificates.

                  Initial Purchasers: Means, collectively, Morgan Stanley & Co.
         Incorporated, Donaldson, Lufkin & Jenrette Securities Corporation,
         Merrill, Lynch, Pierce, Fenner & Smith Incorporated and Salomon Smith
         Barney Inc.

                  Institutional Accredited Investor: Means an institutional
         investor that is an "accredited investor" within the meaning set forth
         in Rule 501(a)(1), (2), (3) or (7) of Regulation D under the Securities
         Act.

                  Intercreditor Agreement: Means the Intercreditor Agreement
         dated as of October 6, 1998 among the Trustee, the Other Trustees, the
         Liquidity Provider, the liquidity provider relating to the Certificates
         issued under (and as defined in) each of the Other Pass Through Trust
         Agreements, and Wilmington Trust Company, as Subordination Agent and as
         trustee thereunder, as amended, supplemented or otherwise modified from
         time to time in accordance with its terms.

                  Investors: Means the Initial Purchasers together with all
         subsequent beneficial owners of the Certificates.

                  Issuance Date: Means the date of the issuance of the Initial
         Certificates.

                  Lease: Means, with respect to each Leased Aircraft, the lease
         between an Owner Trustee, as the lessor, and the Company, as the
         lessee, referred to in the related Indenture, as such lease may be
         amended, supplemented or otherwise modified in accordance with its
         terms.

                  Leased Aircraft: Has the meaning specified in the second
         recital to this Agreement.

                  Liquidity Facility: Means, initially, the Revolving Credit
         Agreement dated as of October 6, 1998 relating to the Certificates,
         between the Liquidity Provider and the Subordination Agent, as agent
         and trustee for the Trustee, and, from and after the replacement of
         such Agreement pursuant to the Intercreditor Agreement, the replacement
         liquidity facility therefor, in each case as amended, supplemented or
         otherwise modified from time to time in accordance with their
         respective terms.

                  Liquidity Provider: Means, initially, ABN AMRO Bank N.V.,
         acting through its Chicago branch and any replacement or successor
         therefor appointed in accordance with the Intercreditor Agreement.
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                  Loan Trustee: With respect to any Equipment Note or the
         Indenture applicable thereto, means the bank or trust company
         designated as trustee under such Indenture, together with any successor
         to such trustee appointed pursuant thereto.

                  Material Adverse Tax Event: Has the meaning specified in
         Section 17.3(a)(4) of the Lease.

                  Non-U.S. Person: Means a Person that is not a "U.S. person",
         as defined in Regulation S.

                  Note Purchase Agreement: Means the Note Purchase Agreement
         dated as of October 6, 1998 among the Trustee, the Other Trustees, the
         Company, the Escrow Agent, the Escrow Paying Agent and the
         Subordination Agent, providing for, among other things, the purchase of
         Equipment Notes by the Trustee on behalf of the Trust, as the same may
         be amended, supplemented or otherwise modified from time to time, in
         accordance with its terms.

                  Notice of Purchase Withdrawal: Has the meaning specified in
         the Deposit Agreement.

                  Offering Circular: Means the Offering Memorandum dated
         September 24, 1998 relating to the offering of the Certificates and the
         certificates issued under the Other Pass Through Trust Agreements.

                  Officer's Certificate: Means a certificate signed, (a) in the
         case of the Company, by any Vice President or more senior officer of
         the Company or, (b) in the case of an Owner Trustee or a Loan Trustee,
         a Responsible Officer of such Owner Trustee or such Loan Trustee, as
         the case may be.

                  Opinion of Counsel: Means a written opinion of legal counsel
         who (a) in the case of counsel for the Company may be (i) the General
         Counsel of the Company, (ii) Cooley Godward LLP, (iii) Vedder, Price,
         Kaufman, Kammholz & Day, or (iv) such other counsel designated by the
         Company and reasonably acceptable to the Trustee and (b) in the case of
         counsel for any Owner Trustee or any Loan Trustee may be such counsel
         as may be designated by any of them whether or not such counsel is an
         employee of any of them, and who shall be reasonably acceptable to the
         Trustee.

                  Other Pass Through Trust Agreements: Means each of the two
         other America West Airlines 1998-1 Pass Through Trust Agreements
         relating to America West Airlines Pass Through Trust, Series 1998-1A-O
         and America West Airlines Pass Through Trust, Series 1998-1C-O, dated
         the date hereof.

                  Other Trustees: Means the trustees under the Other Pass
         Through Trust Agreements, and any successor or other trustee appointed
         as provided therein.

                  Other Trusts: Means the America West Airlines Pass Through
         Trust, Series 1998-1A-O and America West Airlines Pass Through Trust,
         Series 1998-1C-O, created on the date hereof.
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                  Outstanding: When used with respect to Certificates, means, as
         of the date of determination, all Certificates theretofore
         authenticated and delivered under this Agreement, except:

                           (i) Certificates theretofore canceled by the
                  Registrar or delivered to the Trustee or the Registrar for
                  cancellation;

                           (ii) Certificates for which money in the full amount
                  required to make the final distribution with respect to such
                  Certificates pursuant to Section 11.01 hereof has been
                  theretofore deposited with the Trustee in trust for the
                  Holders of such Certificates as provided in Section 4.01
                  pending distribution of such money to such Certificateholders
                  pursuant to payment of such final distribution; and

                           (iii) Certificates in exchange for or in lieu of
                  which other Certificates have been authenticated and delivered
                  pursuant to this Agreement.

                  Owned Aircraft: Has the meaning specified in the second
         recital to this Agreement.

                  Owner Participant: With respect to any Equipment Note relating
         to a Leased Aircraft, means the "Owner Participant" as referred to in
         the Indenture pursuant to which such Equipment Note is issued and any
         permitted successor or assign of such Owner Participant; and Owner
         Participants at any time of determination means all of the Owner
         Participants thus referred to in the Indentures.

                  Owner Trustee: With respect to any Equipment Note relating to
         a Leased Aircraft, means the "Owner Trustee", as referred to in the
         Indenture pursuant to which such Equipment Note is issued, not in its
         individual capacity but solely as trustee; and Owner Trustees means all
         of the Owner Trustees party to any of the Indentures.

                  Participation Agreement: Means each Participation Agreement to
         be entered into by the Trustee pursuant to the Note Purchase Agreement,
         as the same may be amended, supplemented or otherwise modified in
         accordance with its terms.

                  Paying Agent: Means the paying agent maintained and appointed
         for the Certificates pursuant to Section 7.12.

                  Permitted Investments: Means obligations of the United States
         of America or agencies or instrumentalities thereof for the payment of
         which the full faith and credit of the United States of America is
         pledged, maturing in not more than 60 days after the date of
         acquisition thereof or such lesser time as is required for the
         distribution of any Special Payments on a Special Distribution Date.

                  Person: Means any person, including any individual,
         corporation, limited liability company, partnership, joint venture,
         association, joint-stock company, trust, trustee, unincorporated
         organization, or government or any agency or political subdivision
         thereof.
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                  Pool Balance: Means, as of any date, (i) the original
         aggregate face amount of the Certificates less (ii) the aggregate
         amount of all payments made in respect of such Certificates other than
         payments made in respect of interest or premium thereon or
         reimbursement of any costs or expenses incurred in connection therewith
         less (iii) the aggregate amount of unused Deposits distributed as a
         Final Withdrawal other than payments in respect of interest or premium
         thereon. The Pool Balance as of any Distribution Date shall be computed
         after giving effect to the payment of principal, if any, on the
         Equipment Notes or other Trust Property held in such Trust and the
         distribution thereof to be made on such Distribution Date and the
         distribution of the Final Withdrawal to be made on such Distribution
         Date.

                  Pool Factor: Means, as of any date, the quotient (rounded to
         the seventh decimal place) computed by dividing (i) the Pool Balance as
         at such date by (ii) the original aggregate face amount of the
         Certificates. The Pool Factor as of any Distribution Date shall be
         computed after giving effect to the payment of principal, if any, on
         the Equipment Notes or other Trust Property and the distribution
         thereof to be made on such Distribution Date and the distribution of
         the Final Withdrawal to be made on such Distribution Date.

                  PTC Event of Default: Means any failure to pay within 10
         Business Days of the due date thereof: (i) the outstanding Pool Balance
         on the Final Legal Distribution Date or (ii) interest due on the
         Certificates on any Distribution Date (unless the Subordination Agent
         shall have made an Interest Drawing or Drawings (as defined in the
         Intercreditor Agreement), or a withdrawal or withdrawals pursuant to
         Section 3.6(f) of the Intercreditor Agreement, with respect thereto in
         an aggregate amount sufficient to pay such interest and shall have
         distributed such amount to the Trustee).

                  QIB: Means a qualified institutional buyer as defined in Rule
         144A.

                  Record Date: Means (i) for Scheduled Payments to be
         distributed on any Regular Distribution Date, other than the final
         distribution, the 15th day (whether or not a Business Day) preceding
         such Regular Distribution Date, and (ii) for Special Payments to be
         distributed on any Special Distribution Date, other than the final
         distribution, the 15th day (whether or not a Business Day) preceding
         such Special Distribution Date.

                  Register and Registrar: Mean the register maintained and the
         registrar appointed pursuant to Sections 3.04 and 7.12.

                  Registration Event: Means the declaration of the effectiveness
         by the SEC of the Exchange Offer Registration Statement or the Shelf
         Registration Statement.

                  Registration Rights Agreement: Means the Exchange and
         Registration Rights Agreement dated as of October 6, 1998, among the
         Initial Purchasers, the Trustee, the Other Trustees and the Company, as
         amended, supplemented or otherwise modified from time to time in
         accordance with its terms.

                  Regular Distribution Date: With respect to distributions of
         Scheduled Payments in respect of the Certificates, means each date
         designated as a Regular Distribution Date
<PAGE>   16
                                      -11-


         in the Certificates issued pursuant to this Agreement, until payment of
         all the Scheduled Payments to be made under the Equipment Notes held in
         the Trust have been made; provided, however, that, if any such day
         shall not be a Business Day, the related distribution shall be made on
         the next succeeding Business Day without additional interest.

                  Regulation S: Means Regulation S under the Securities Act or
         any successor regulation thereto.

                  Regulation S Definitive Certificates: Has the meaning
         specified in Section 3.01(e).

                  Regulation S Global Certificates: Has the meaning specified in
         Section 3.01(d).

                  Related Pass Through Trust Agreement: Means the Pass Through
         Trust Agreement relating to the America West Airlines Pass Through
         Trust, Series 1998-1B-S, dated the date hereof, between the Company and
         the institution acting as trustee thereunder, which agreement becomes
         effective upon the execution and delivery of the Assignment and
         Assumption Agreement pursuant to Section 11.01.

                  Related Trust: Means the America West Pass Through Trust,
         Series 1998-1B-S, formed under the Related Pass Through Trust
         Agreement.

                  Related Trustee: Means the trustee under the Related Pass
         Through Trust Agreement.

                  Responsible Officer: With respect to the Trustee, any Loan
         Trustee and any Owner Trustee, means any officer in the Corporate Trust
         Office of the Trustee, Loan Trustee or Owner Trustee or any other
         officer customarily performing functions similar to those performed by
         the persons who at the time shall be such officers, respectively, or to
         whom any corporate trust matter is referred because of his knowledge of
         and familiarity with a particular subject.

                  Restricted Definitive Certificates: Has the meaning specified
         in Section 3.01(e).

                  Restricted Global Certificate: Has the meaning specified in
         Section 3.01(c).

                  Restricted Legend: Has the meaning specified in Section 3.02.

                  Restricted Period: Has the meaning specified in Section
         3.01(d).

                  Rule 144A: Means Rule 144A under the Securities Act and any
         successor rule thereto.

                  Scheduled Payment: With respect to any Equipment Note, means
         (i) any payment of principal or interest on such Equipment Note (other
         than any such payment which is not in fact received by the
         Subordination Agent within five days of the date on which such payment
         is scheduled to be made) due from the obligor thereon or (ii) any
         payment
<PAGE>   17
                                      -12-


         of interest on the Certificates with funds drawn under any Liquidity
         Facility, which payment represents the installment of principal at the
         stated maturity of such installment of principal on such Equipment
         Note, the payment of regularly scheduled interest accrued on the unpaid
         principal amount of such Equipment Note, or both; provided that any
         payment of principal, premium, if any, or interest resulting from the
         redemption or purchase of any Equipment Note shall not constitute a
         Scheduled Payment.

                  SEC: Means the Securities and Exchange Commission, as from
         time to time constituted or created under the United States Securities
         Exchange Act of 1934, as amended, or, if at any time after the
         execution of this instrument such Commission is not existing and
         performing the duties now assigned to it under the Trust Indenture Act,
         then the body performing such duties on such date.

                  Securities Act: Means the United States Securities Act of
         1933, as amended from time to time, or any successor thereto.

                  Shelf Registration Statement: Means the shelf registration
         statement which may be required to be filed by the Company with the SEC
         pursuant to any Registration Rights Agreement, other than an Exchange
         Offer Registration Statement.

                  Special Distribution Date: Means each date on which a Special
         Payment is to be distributed as specified in this Agreement; provided,
         however, that, if any such day shall not be a Business Day, the related
         distribution shall be made on the next succeeding Business Day without
         additional interest.

                  Special Redemption Premium: Means the premium payable by the
         Company in respect of the Final Withdrawal pursuant to the Note
         Purchase Agreement.

                  Special Payment: Means any payment (other than a Scheduled
         Payment) in respect of, or any proceeds of, any Equipment Note or Trust
         Indenture Estate (as defined in each Indenture) or Special Redemption
         Premium.

                  Special Payments Account: Means the account or accounts
         created and maintained pursuant to Section 4.01(b).

                  Subordination Agent: Has the meaning specified in the
         Intercreditor Agreement.

                  Substitute Aircraft: Has the meaning specified in the Note
         Purchase Agreement.

                  Tax: Means all license, recording, documentary, registration
         and other similar fees and all taxes, levies, imposts, duties, charges,
         assessments or withholdings of any nature whatsoever imposed by any
         Taxing Authority, together with any penalties, additions to tax, fines
         or interest thereon or additions thereto.

                  Taxing Authority: Means any federal, state or local government
         or other taxing authority in the United States, any foreign government
         or any political subdivision or taxing authority thereof, any
         international taxing authority or any territory or possession of the
         United States or any taxing authority thereof.
<PAGE>   18
                                      -13-


                  TIN: Has the meaning specified in Section 7.16.

                  Transfer Date: Has the meaning specified in Section 11.01.

                  Triggering Event: Has the meaning assigned to such term in the
         Intercreditor Agreement.

                  Trust: Means the trust created by this Agreement, the estate
         of which consists of the Trust Property.

                  Trust Indenture Act: Means the United States Trust Indenture
         Act of 1939, as amended from time to time, or any successor thereto.

                  Trust Property: Means (i) the Equipment Notes held as the
         property of the Trust and, subject to the Intercreditor Agreement, all
         monies at any time paid thereon and all monies due and to become due
         thereunder, (ii) funds from time to time deposited in the Certificate
         Account and the Special Payments Account and, subject to the
         Intercreditor Agreement, any proceeds from the sale by the Trustee
         pursuant to Article VI hereof of any Equipment Note and (iii) all
         rights of the Trust and the Trustee, on behalf of the Trust, under the
         Intercreditor Agreement, the Escrow Agreement, the Note Purchase
         Agreement and the Liquidity Facilities, including, without limitation,
         all rights to receive certain payments thereunder, and all monies paid
         to the Trustee on behalf of the Trust pursuant to the Intercreditor
         Agreement or the Liquidity Facilities, provided, that rights with
         respect to the Deposits or under the Escrow Agreement, except for the
         right to direct withdrawals for the purchase of Equipment Notes to be
         held herein, will not constitute Trust Property.

                  Trustee: Means Wilmington Trust Company, or its successor in
         interest, and any successor or other trustee appointed as provided
         herein.

                  Trustee's Lien: Has the meaning specified in Section 7.17.

                  Unindemnified Tax: Means (i) any Tax imposed on the net
         income, net worth or capital, or any franchise Tax or similar doing
         business Tax, of the Pass Through Trustee (other than any such Tax
         imposed as a result of the Company's assumption of the Equipment Notes
         pursuant to the purchase of an aircraft on an EBO Date or a Material
         Adverse Tax Event), (ii) any withholding Tax imposed by the United
         States (including, without limitation, any withholding Tax imposed by
         the United States which is imposed or increased as a result of the Pass
         Through Trustee failing to deliver to the Company any certificate or
         document necessary to establish that payments under this Agreement are
         exempt from withholding Tax), and (iii) any Avoidable Tax.

                  Section 1.02. Compliance Certificates and Opinions. Upon any
application or request (except with respect to matters set forth in Article II)
by the Company, any Owner Trustee or any Loan Trustee to the Trustee to take any
action under any provision of this Agreement, the Company, such Owner Trustee or
such Loan Trustee, as the case may be, shall furnish to the Trustee (i) an
Officer's Certificate stating that, in the opinion of the signers, all
conditions precedent, if any, provided for in this Agreement relating to the
proposed action have
<PAGE>   19
                                      -14-


been complied with and (ii) an Opinion of Counsel stating that in the opinion of
such counsel all such conditions precedent, if any, have been complied with,
except that in the case of any such application or request as to which the
furnishing of such documents is specifically required by any provision of this
Agreement relating to such particular application or request, no additional
certificate or opinion need be furnished.

                  Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Agreement (other than a certificate
provided pursuant to Section 8.04(e)) shall include:

                  (1) a statement that each individual signing such certificate
         or opinion has read such covenant or condition and the definitions in
         this Agreement relating thereto;

                  (2) a brief statement as to the nature and scope of the
         examination or investigation upon which the statements or opinions
         contained in such certificate or opinion are based;

                  (3) a statement that, in the opinion of each such individual,
         he has made such examination or investigation as is necessary to enable
         him to express an informed opinion as to whether or not such covenant
         or condition has been complied with; and

                  (4) a statement as to whether, in the opinion of each such
         individual, such condition or covenant has been complied with.

                  Section 1.03. Form of Documents Delivered to Trustee. In any
case where several matters are required to be certified by, or covered by an
opinion of, any specified Person, it is not necessary that all such matters be
certified by, or covered by the opinion of, only one such Person, or that they
be so certified or covered by only one document, but one such Person may certify
or give an opinion with respect to some matters and one or more other such
Persons as to other matters and any such Person may certify or give an opinion
as to such matters in one or several documents.

                  Where any Person is required to make, give or execute two or
more applications, requests, consents, certificates, statements, opinions or
other instruments under this Agreement or, in respect of the Certificates, this
Agreement, they may, but need not, be consolidated and form one instrument.

                  Section 1.04. Directions of Certificateholders. (a) Any
direction, consent, request, demand, authorization, notice, waiver or other
action provided by this Agreement to be given or taken by Certificateholders (a
"Direction") may be embodied in and evidenced by one or more instruments of
substantially similar tenor signed by such Certificateholders in person or by an
agent or proxy duly appointed in writing; and, except as herein otherwise
expressly provided, such action shall become effective when such instrument or
instruments are delivered to the Trustee and, where it is hereby expressly
required pursuant to this Agreement, to the Company or any Loan Trustee. Proof
of execution of any such instrument or of a writing appointing any such agent or
proxy shall be sufficient for any purpose of this Agreement and conclusive in
favor of the Trustee, the Company and any Loan Trustee, if made in the manner
provided in this Section.
<PAGE>   20
                                      -15-


                  (b) The fact and date of the execution by any Person of any
such instrument or writing may be proved by the certificate of any notary public
or other officer of any jurisdiction authorized to take acknowledgments of deeds
or administer oaths that the Person executing such instrument acknowledged to
him the execution thereof, or by an affidavit of a witness to such execution
sworn to before any such notary or such other officer and where such execution
is by an officer of a corporation or association or a member of a partnership,
on behalf of such corporation, association or partnership, such certificate or
affidavit shall also constitute sufficient proof of his authority. The fact and
date of the execution of any such instrument or writing, or the authority of the
Person executing the same, may also be proved in any other reasonable manner
which the Trustee deems sufficient.

                  (c) In determining whether the Certificateholders of the
requisite Fractional Undivided Interests of Certificates Outstanding have given
any Direction under this Agreement, Certificates owned by the Company or any
Affiliate thereof shall be disregarded and deemed not to be Outstanding for
purposes of any such determination. In determining whether the Trustee shall be
protected in relying upon any such Direction, only Certificates which the
Trustee knows to be so owned shall be so disregarded. Notwithstanding the
foregoing, (i) if any such Person owns 100% of the Certificates Outstanding,
such Certificates shall not be so disregarded, and (ii) if any amount of
Certificates so owned by any such Person have been pledged in good faith, such
Certificates shall not be disregarded if the pledgee establishes to the
satisfaction of the Trustee the pledgee's right so to act with respect to such
Certificates and that the pledgee is not the Company or any Affiliate thereof.

                  (d) For all purposes of this Agreement, all Initial
Certificates and all Exchange Certificates shall vote and take all other actions
of Certificateholders together as one series of Certificates.

                  (e) The Company may at its option, by delivery of an Officer's
Certificate to the Trustee, set a record date to determine the
Certificateholders entitled to give any Direction. Notwithstanding Section
316(c) of the Trust Indenture Act, such record date shall be the record date
specified in such Officer's Certificate, which shall be a date not more than 30
days prior to the first solicitation of Certificateholders in connection
therewith. If such a record date is fixed, such Direction may be given before or
after such record date, but only the Certificateholders of record at the close
of business on such record date shall be deemed to be Certificateholders for the
purposes of determining whether Certificateholders of the requisite proportion
of Outstanding Certificates have authorized or agreed or consented to such
Direction, and for that purpose the Outstanding Certificates shall be computed
as of such record date; provided that no such Direction by the
Certificateholders on such record date shall be deemed effective unless it shall
become effective pursuant to the provisions of this Agreement not later than one
year after such record date.

                  (f) Any Direction by the Holder of any Certificate shall bind
the Holder of every Certificate issued upon the transfer thereof or in exchange
therefor or in lieu thereof, whether or not notation of such Direction is made
upon such Certificate.
<PAGE>   21
                                      -16-


                  (g) Except as otherwise provided in Section 1.04(c),
Certificates owned by or pledged to any Person shall have an equal and
proportionate benefit under the provisions of this Agreement, without
preference, priority, or distinction as among all of the Certificates.

                                   ARTICLE II

                       ORIGINAL ISSUANCE OF CERTIFICATES;
                         ACQUISITION OF EQUIPMENT NOTES

                  Section 2.01. Issuance of Certificates; Acquisition of
Equipment Notes. (a) The Trustee is hereby directed (i) to execute and deliver
the Intercreditor Agreement, the Registration Rights Agreement, the Escrow
Agreement and the Note Purchase Agreement on or prior to the Issuance Date, each
in the form delivered to the Trustee by the Company and (ii) subject to the
respective terms thereof, to perform its obligations thereunder. Upon request of
the Company and the satisfaction or waiver of the closing conditions specified
in the Certificate Purchase Agreement, the Trustee shall execute, deliver,
authenticate, issue and sell Certificates in authorized denominations equalling
in the aggregate the amount set forth, with respect to the Trust, in Schedule II
to the Certificate Purchase Agreement evidencing the entire ownership interest
in the Trust, which amount equals the maximum aggregate principal amount of
Equipment Notes which may be purchased by the Trustee pursuant to the Note
Purchase Agreement. Except as provided in Sections 3.04, 3.05, 3.06, 3.07 and
3.10 hereof, the Trustee shall not execute, authenticate or deliver Certificates
in excess of the aggregate amount specified in this paragraph.

                  (b) On or after the Issuance Date, the Company may deliver
from time to time to the Trustee a Delivery Notice relating to one or more
Equipment Notes. After receipt of a Delivery Notice and in any case no later
than one Business Day prior to a Delivery Date as to which such Delivery Notice
relates (the "Applicable Delivery Date") (or, if the Issuance Date is an
Applicable Delivery Date, on the Issuance Date), the Trustee shall (as and when
specified in the Delivery Notice) instruct the Escrow Agent to provide a Notice
of Purchase Withdrawal to the Depositary requesting (A) the withdrawal of one or
more Deposits on the Applicable Delivery Date in accordance with and to the
extent permitted by the terms of the Escrow Agreement and the Deposit Agreement
and (B) the payment of all, or a portion, of such Deposit or Deposits in an
amount equal in the aggregate to the purchase price of such Equipment Notes to
or on behalf of the Owner Trustee or the Company, as the case may be, issuing
such Equipment Notes, all as shall be described in the Delivery Notice; provided
that, if the Issuance Date is an Applicable Delivery Date, such purchase price
shall be paid from a portion of the proceeds of the sale of the Certificates.
The Trustee shall (as and when specified in such Delivery Notice), subject to
the conditions set forth in Section 2 of the Note Purchase Agreement, enter into
and perform its obligations under the Participation Agreement specified in such
Delivery Notice (the "Applicable Participation Agreement") and cause such
certificates, documents and legal opinions relating to the Trustee to be duly
delivered as required by the Applicable Participation Agreement. If at any time
prior to the Applicable Delivery Date, the Trustee receives a notice of
postponement pursuant to Section 2(e) or 2(f) of the Note Purchase Agreement,
then the Trustee shall give the Depositary (with a copy to the Escrow Agent) a
notice of cancellation of such Notice of Purchase Withdrawal relating to such
Deposit or
<PAGE>   22
                                      -17-


Deposits on such Applicable Delivery Date. Upon satisfaction of the conditions
specified in the Note Purchase Agreement and the Applicable Participation
Agreement, the Trustee shall purchase the applicable Equipment Notes with the
proceeds of the withdrawals of one or more Deposits made on the Applicable
Delivery Date in accordance with the terms of the Deposit Agreement and the
Escrow Agreement (or, if the Issuance Date is the Applicable Delivery Date with
respect to such Applicable Participation Agreement, from a portion of the
proceeds of the sale of the Certificates). The purchase price of such Equipment
Notes shall equal the principal amount of such Equipment Notes. Amounts
withdrawn from such Deposit or Deposits in excess of the purchase price of the
Equipment Notes or to the extent not applied on the Applicable Delivery Date to
the purchase price of the Equipment Notes, shall be re-deposited by the Trustee
with the Depositary on the Applicable Delivery Date in accordance with the terms
of the Deposit Agreement.

                  Section 2.02. Withdrawal of Deposits. If any Deposits remain
outstanding on the Business Day next succeeding the Cut-Off Date, (i) (A) the
Trustee shall give the Escrow Agent notice that the Trustee's obligation to
purchase Equipment Notes under the Note Purchase Agreement has terminated and
instruct the Escrow Agent to provide a notice of Final Withdrawal to the
Depositary substantially in the form of Exhibit B to the Deposit Agreement (the
"Final Withdrawal Notice") and (B) the Trustee will make a demand upon the
Company under the Note Purchase Agreement for an amount equal to the Special
Redemption Premium, if applicable, such payment to be made on the Final
Withdrawal Date.

                  Section 2.03. Acceptance by Trustee. The Trustee, upon the
execution and delivery of this Agreement, acknowledges its acceptance of all
right, title and interest in and to the Trust Property and declares that the
Trustee holds and will hold such right, title and interest for the benefit of
all then present and future Certificateholders, upon the trusts herein set
forth. Subject to Section 7.14, the Trustee shall take all actions reasonably
necessary to effect the registration of all such Equipment Notes in the name of
the Subordination Agent. By its payment for and acceptance of each Certificate
issued to it under this Agreement, each initial Certificateholder as grantor of
the Trust thereby joins in the creation and declaration of the Trust.

                  Section 2.04. Limitation of Powers. The Trust is constituted
solely for the purpose of making the investment in the Equipment Notes, and,
except as set forth herein, the Trustee shall not be authorized or empowered to
acquire any other investments or engage in any other activities and, in
particular, the Trustee shall not be authorized or empowered to do anything that
would cause such Trust to fail to qualify as a "grantor trust" for federal
income tax purposes (including as subject to this restriction, acquiring any
Aircraft (as defined in the respective Indentures) by bidding such Equipment
Notes or otherwise, or taking any action with respect to any such Aircraft once
acquired).

                                   ARTICLE III

                                THE CERTIFICATES

                  Section 3.01. Title, Form, Denomination and Execution of
Certificates. (a) The Initial Certificates shall be known as the "7.12% Initial
Pass Through Certificates, Series 1998-1B-O" and the Exchange Certificates shall
be known as the "7.12% Exchange Pass Through
<PAGE>   23
                                      -18-


Certificates, Series 1998-1B-O", in each case, of the Trust. Each Certificate
will represent a fractional undivided interest in the Trust and shall be
substantially in the form set forth as Exhibit A hereto, with such appropriate
insertions, omissions, substitutions and other variations as are required or
permitted by this Agreement and may have such letters, numbers or other marks of
identification and such legends or endorsements placed thereon as may be
required to comply with the rules of any securities exchange or as may,
consistently herewith, be determined by the Trustee or the officers executing
such Certificates, as evidenced by the Trustee's or officer's execution of the
Certificates (provided that such letters, numbers or other marks of
identification and such legends or endorsements are in a form acceptable to the
Company). At the Escrow Agent's request under the Escrow Agreement, the Trustee
shall affix the corresponding Escrow Receipt to each Certificate. In any event,
any transfer or exchange of any Certificate shall also effect a transfer or
exchange of the related Escrow Receipt. Prior to the Final Withdrawal Date, no
transfer or exchange of any Certificate shall be permitted unless the
Corresponding Escrow Receipt is attached thereto and also is so transferred or
exchanged. By acceptance of any Certificate to which an Escrow Receipt is
attached, each Holder of such a Certificate acknowledges and accepts the
restrictions on transfer of the Escrow Receipt set forth herein and in the
Escrow Agreement.

                  (b) The Initial Certificates shall be issued only in fully
registered form without coupons and only in denominations of $100,000 or
integral multiples of $1,000 in excess thereof, except that one Certificate may
be issued in a different denomination. The Exchange Certificates will be issued
in denominations of $1,000 or integral multiples thereof, except that one
Certificate may be issued in a different denomination. Each Certificate shall be
dated the date of its authentication. The aggregate Fractional Undivided
Interest of Certificates shall not at any time exceed $41,154,000.

                  (c) The Initial Certificates offered and sold in reliance on
Rule 144A shall be issued in the form of one or more Global Certificates
substantially in the form of Exhibit A hereto with such applicable legends as
are provided for in Section 3.02 (each a "Restricted Global Certificate") duly
executed and authenticated by the Trustee as hereinafter provided. Such
Restricted Global Certificates shall be in registered form and be registered in
the name of DTC and deposited with the Trustee, at its Corporate Trust Office,
as custodian for DTC. The aggregate principal amount of any Restricted Global
Certificate may from time to time be increased or decreased by adjustments made
on the records of the Trustee, as custodian for DTC for such Restricted Global
Certificate, as provided in Section 3.06 hereof, which adjustments shall be
conclusive as to the aggregate principal amount of any such Global Certificate.

                  (d) The Initial Certificates offered and sold outside the
United States in reliance on Regulation S shall be issued in the form of one or
more global Certificates substantially in the form of Exhibit A hereto (each a
"Regulation S Global Certificate") duly executed and authenticated by the
Trustee as hereinafter provided. Such Regulation S Global Certificates shall be
in registered form and be registered in the name of DTC and deposited with the
Trustee, at its Corporate Trust Office, as custodian for DTC, for credit
initially and during the Restricted Period (hereinafter defined) to the
respective accounts of beneficial owners of such Certificates (or to such other
accounts as they may direct) at Morgan Guaranty Trust Company of New York,
Brussels office, as operator of Euroclear or Cedel. As used herein, the term
"Restricted Period", with respect to the Regulation S Global Certificates
offered and sold in
<PAGE>   24
                                      -19-


reliance on Regulation S, means the period of 40 consecutive days beginning on
and including the later of (i) the day on which the Certificates are first
offered to persons other than distributors (as defined in Regulation S) in
reliance on Regulation S and (ii) the date of the closing of the offering under
the Certificate Purchase Agreement. The aggregate principal amount of any
Regulation S Global Certificate may from time to time be increased or decreased
by adjustments made on the records of the Trustee, as custodian for DTC for such
Global Certificate, as provided in Section 3.06 hereof, which adjustments shall
be conclusive as to the aggregate principal amount of any such Global
Certificate. The Restricted Global Certificate and Regulation S Global
Certificate are sometimes collectively referred to herein as the "Global
Certificates".

                  (e) Initial Certificates offered and sold to any Institutional
Accredited Investor which is not a QIB in a transaction exempt from registration
under the Securities Act (and other than as described in Section 3.01(d)) shall
be issued substantially in the form of Exhibit A hereto in definitive, fully
registered form without interest coupons with such applicable legends as are
provided for in Section 3.02 (the "Restricted Definitive Certificates") duly
executed and authenticated by the Trustee as hereinafter provided. Certificates
issued pursuant to Section 3.05(b) in exchange for interests in a Regulation S
Global Certificate shall be issued in definitive, fully registered form without
interest coupons (the "Regulation S Definitive Certificates"). The Restricted
Definitive Certificates and the Regulation S Definitive Certificates are
sometimes collectively referred to herein as the "Definitive Certificates".

                  (f) The Exchange Certificates shall be issued in the form of
one or more global Certificates substantially in the form of Exhibit A hereto
(each, a "Global Exchange Certificate"), except that (i) the Restricted Legend
(hereinafter defined) shall be omitted and (ii) such Exchange Certificates shall
contain such appropriate insertions, omissions, substitutions and other
variations from the form set forth in Exhibit A hereto relating to the nature of
the Exchange Certificates as the Responsible Officer of the Trustee executing
such Exchange Certificates on behalf of the Trust may determine, as evidenced by
such officer's execution on behalf of the Trust of such Exchange Certificates.
Such Global Exchange Certificates shall be in registered form and be registered
in the name of DTC and deposited with the Trustee, at its Corporate Trust
Office, as custodian for DTC. The aggregate principal amount of any Global
Exchange Certificate may from time to time be increased or decreased by
adjustments made on the records of the Trustee, as custodian for DTC for such
Global Exchange Certificate, which adjustments shall be conclusive as to the
aggregate principal amount of any such Global Exchange Certificate. Subject to
clause (i) and (ii) of the first sentence of this Section 3.01(f), the terms
hereof applicable to Restricted Global Certificates and/or Global Certificates
shall apply to the Global Exchange Certificates, mutatis mutandis.

                  (g) The Definitive Certificates shall be in registered form
and shall be typed, printed, lithographed or engraved or produced by any
combination of these methods or may be produced in any other manner, all as
determined by the officers executing such Certificates, as evidenced by their
execution of such Certificates.

                  Section 3.02. Restrictive Legends. All Initial Certificates
issued pursuant to this Agreement for resale pursuant to Rule 144A or offered
and sold to any Institutional Accredited Investor which is not a QIB (including
any Global Certificate issued upon registration of
<PAGE>   25
                                      -20-


transfer, in exchange for or in lieu of such Certificates) shall be "Restricted
Certificates" and shall bear a legend to the following effect (the "Restricted
Legend") unless the Company and the Trustee determine otherwise consistent with
applicable law:

                  THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE U.S.
         SECURITIES ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND
         ACCORDINGLY, MAY NOT BE OFFERED OR SOLD WITHIN THE UNITED STATES OR TO,
         OR FOR THE ACCOUNT OR BENEFIT OF, ANY PERSONS EXCEPT AS SET FORTH IN
         THE FOLLOWING SENTENCE. BY ITS ACQUISITION HEREOF, THE HOLDER (1)
         REPRESENTS THAT (A) IT IS A "QUALIFIED INSTITUTIONAL BUYER" (AS DEFINED
         IN RULE 144A UNDER THE SECURITIES ACT), (B) IT IS AN INSTITUTIONAL
         "ACCREDITED INVESTOR" (AS DEFINED IN RULE 501(a)(1), (2), (3) OR (7) OF
         REGULATION D UNDER THE SECURITIES ACT) (AN "INSTITUTIONAL ACCREDITED
         INVESTOR") OR (C) IT IS NOT A U.S. PERSON AND IS ACQUIRING THIS
         CERTIFICATE IN AN OFFSHORE TRANSACTION IN COMPLIANCE WITH REGULATION S
         UNDER THE SECURITIES ACT; (2) AGREES THAT IT WILL NOT WITHIN TWO YEARS
         AFTER THE LATER OF THE ORIGINAL ISSUANCE OF THIS CERTIFICATE OR THE
         LAST DATE ON WHICH THIS CERTIFICATE WAS HELD BY AMERICA WEST AIRLINES,
         INC., THE TRUSTEE OR ANY AFFILIATE OF ANY OF SUCH PERSONS RESELL OR
         OTHERWISE TRANSFER THIS CERTIFICATE EXCEPT (A) TO AMERICA WEST
         AIRLINES, INC., (B) TO A QUALIFIED INSTITUTIONAL BUYER IN COMPLIANCE
         WITH RULE 144A UNDER THE SECURITIES ACT, (C) OUTSIDE THE UNITED STATES
         IN AN OFFSHORE TRANSACTION IN COMPLIANCE WITH RULE 904 UNDER THE
         SECURITIES ACT, (D) PURSUANT TO THE EXEMPTION FROM REGISTRATION
         PROVIDED BY RULE 144 UNDER THE SECURITIES ACT (IF AVAILABLE) OR (E)
         PURSUANT TO AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES
         ACT; AND (3) AGREES THAT IF IT SHOULD RESELL OR OTHERWISE TRANSFER THIS
         CERTIFICATE IT WILL DELIVER TO EACH PERSON TO WHOM THIS CERTIFICATE IS
         TRANSFERRED A NOTICE SUBSTANTIALLY TO THE EFFECT OF THIS LEGEND. IN
         CONNECTION WITH ANY TRANSFER OF THIS CERTIFICATE WITHIN TWO YEARS AFTER
         THE LATER OF THE ORIGINAL ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE
         ON WHICH THIS CERTIFICATE WAS HELD BY AMERICA WEST AIRLINES, INC., THE
         TRUSTEE OR ANY AFFILIATE OF ANY OF SUCH PERSONS, THE HOLDER MUST CHECK
         THE APPROPRIATE BOX SET FORTH ON THE REVERSE HEREOF RELATING TO THE
         MANNER OF SUCH TRANSFER AND SUBMIT THIS CERTIFICATE TO THE TRUSTEE. AS
         USED HEREIN, THE TERMS "OFFSHORE TRANSACTION", "UNITED STATES" AND
         "U.S. PERSON" HAVE THE MEANINGS GIVEN TO THEM BY REGULATION S UNDER THE
         SECURITIES ACT. THE PASS THROUGH TRUST AGREEMENT CONTAINS A PROVISION
         REQUIRING THE TRUSTEE TO REFUSE TO REGISTER ANY TRANSFER OF THIS
         CERTIFICATE IN VIOLATION OF THE FOREGOING RESTRICTIONS.

                  Each Global Certificate shall bear the following legend on the
face thereof:
<PAGE>   26
                                      -21-


                  UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED
         REPRESENTATIVE OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION
         ("DTC"), TO THE TRUSTEE OR ITS AGENT FOR REGISTRATION OF TRANSFER,
         EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IN EXCHANGE FOR THIS
         CERTIFICATE IS REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER
         NAME AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY
         PAYMENT HEREON IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS
         REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE
         OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS
         WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN
         INTEREST HEREIN.

                  TRANSFERS OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO
         TRANSFERS IN WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A
         SUCCESSOR THEREOF OR SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS
         OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO TRANSFERS MADE IN
         ACCORDANCE WITH THE RESTRICTIONS SET FORTH IN SECTIONS 3.05 AND 3.06 OF
         THE PASS THROUGH TRUST AGREEMENT REFERRED TO HEREIN.

                  Section 3.03. Authentication of Certificates. (a) On the
Issuance Date, the Trustee shall duly execute, authenticate and deliver
Certificates in authorized denominations equalling in the aggregate the amount
set forth, with respect to the Trust, in Schedule II to the Certificate Purchase
Agreement, evidencing the entire ownership of the Trust, which amount equals the
maximum aggregate principal amount of Equipment Notes which may be purchased by
the Trustee pursuant to the Note Purchase Agreement.

                  (b) No Certificate shall be entitled to any benefit under this
Agreement or be valid or obligatory for any purpose, unless there appears on
such Certificate a certificate of authentication substantially in the form
provided for herein executed by the Trustee by the manual signature of one of
its authorized signatories, and such certificate upon any Certificate shall be
conclusive evidence, and the only evidence, that such Certificate has been duly
authenticated and delivered hereunder.

                  (c) Certificates bearing the manual or facsimile signature of
an individual who was, at the time when such signature was affixed, authorized
to sign on behalf of the Trustee shall be valid and binding obligations of the
Trust notwithstanding that such individual has ceased to be so authorized prior
to the authentication and delivery of such Certificates or did not hold such
office on the date of such Certificates.

                  Section 3.04. Transfer and Exchange. The Trustee shall cause
to be kept at the office or agency to be maintained by it in accordance with the
provisions of Section 7.12 a register (the "Register") of the Certificates in
which, subject to such reasonable regulations as it may prescribe, the Trustee
shall provide for the registration of such Certificates and of transfers and
exchanges of such Certificates as herein provided. The Trustee shall initially
be the registrar (the "Registrar") for the purpose of registering such
Certificates and transfers and exchanges of 
<PAGE>   27
                                      -22-


such Certificates as herein provided. The Company, upon notice to the Trustee,
may change the Registrar at any time.

                  All Certificates issued upon any registration of transfer or
exchange of Certificates shall be valid obligations of the Trust, evidencing the
same interest therein, and entitled to the same benefits under this Trust
Agreement, as the Certificates surrendered upon such registration of transfer or
exchange.

                  A Certificateholder may transfer a Certificate, or request
that a Certificate be exchanged for Certificates in an aggregate Fractional
Undivided Interest equal to the Fractional Undivided Interest of such
Certificate surrendered for exchange of other authorized denominations, by
surrender of such Certificate to the Trustee with the form of transfer notice
thereon duly completed and executed, and otherwise complying with the terms of
this Agreement, including providing evidence of compliance with any restrictions
on transfer, in form satisfactory to the Trustee and the Registrar; provided
that no exchanges of Initial Certificates for Exchange Certificates shall occur
until an Exchange Offer Registration Statement shall have been declared
effective by the SEC (notice of which shall be provided to the Trustee by the
Company). No such transfer shall be effected until, and such transferee shall
succeed to the rights of a Certificateholder only upon, final acceptance and
registration of the transfer by the Registrar in the Register. Prior to the
registration of any transfer by a Certificateholder as provided herein, the
Trustee shall treat the person in whose name the Certificate is registered as
the owner thereof for all purposes, and the Trustee shall not be affected by
notice to the contrary. Furthermore, DTC shall, by acceptance of a Global
Certificate, agree that transfers of beneficial interests in such Global
Certificate may be effected only through a book-entry system maintained by DTC
(or its agent) and that ownership of a beneficial interest in the Certificate
shall be required to be reflected in a book-entry. When Certificates are
presented to the Registrar with a request to register the transfer thereof or to
exchange them for other authorized denominations of a Certificate in a
Fractional Undivided Interest equal to the aggregate Fractional Undivided
Interest of Certificates surrendered for exchange, the Registrar shall register
the transfer or make the exchange as requested if its requirements for such
transactions are met.

                  To permit registrations of transfers and exchanges in
accordance with the terms, conditions and restrictions hereof, the Trustee shall
execute and authenticate Certificates at the Registrar's request. No service
charge shall be made to a Certificateholder for any registration of transfer or
exchange of Certificates, but the Trustee shall require payment of a sum
sufficient to cover any tax or governmental charge that may be imposed in
connection with any transfer or exchange of Certificates. All Certificates
surrendered for registration of transfer or exchange shall be canceled and
subsequently destroyed by the Trustee.

                  Section 3.05. Book-Entry Provisions for Restricted Global
Certificates and Regulation S Global Certificates. (a) Members of, or
participants in, DTC ("Agent Members") shall have no rights under this Agreement
with respect to any Global Certificate held on their behalf by DTC, or the
Trustee as its custodian, and DTC may be treated by the Trustee and any agent of
the Trustee as the absolute owner of such Global Certificate for all purposes
whatsoever. Notwithstanding the foregoing, nothing herein shall prevent the
Trustee or any agent of the Trustee from giving effect to any written
certification, proxy or other authorization furnished by DTC or shall impair, as
between DTC and its Agent Members, the operation of customary
<PAGE>   28
                                      -23-


practices governing the exercise of the rights of a holder of any Certificate.
Upon the issuance of any Global Certificate, the Registrar or its duly appointed
agent shall record DTC as the registered holder of such Global Certificate.

                  (b) Transfers of any Global Certificate shall be limited to
transfers of such Restricted Global Certificate or Regulation S Global
Certificate in whole, but not in part, to DTC. Beneficial interests in the
Restricted Global Certificate and any Regulation S Global Certificate may be
transferred in accordance with the rules and procedures of DTC and the
provisions of Section 3.06. Beneficial interests in a Restricted Global
Certificate or a Regulation S Global Certificate shall be delivered to all
beneficial owners thereof in the form of Restricted Definitive Certificates or
Regulation S Definitive Certificates, as the case may be, if (i) DTC notifies
the Trustee that it is unwilling or unable to continue as depositary for such
Restricted Global Certificate or Regulation S Global Certificate, as the case
may be, and a successor depositary is not appointed by the Trustee within 90
days of such notice, and (ii) after the occurrence and during the continuance of
an Event of Default, owners of beneficial interests in a Global Certificate with
Fractional Undivided Interests aggregating not less than a majority in interest
in the Trust advise the Trustee, the Company and DTC through Agent Members in
writing that the continuation of a book-entry system through DTC or its
successor is no longer in their best interests.

                  (c) Any beneficial interest in one of the Global Certificates
that is transferred to a Person who takes delivery in the form of an interest in
another Global Certificate will, upon such transfer, cease to be an interest in
such Global Certificate and become an interest in the other Global Certificate
and, accordingly, will thereafter be subject to all transfer restrictions, if
any, and other procedures applicable to beneficial interests in such other
Global Certificate for as long as it remains such an interest.

                  (d) In connection with the transfer of an entire Restricted
Global Certificate or an entire Regulation S Global Certificate to the
beneficial owners thereof pursuant to paragraph (b) of this Section 3.05, such
Restricted Global Certificate or Regulation S Global Certificate, as the case
may be, shall be deemed to be surrendered to the Trustee for cancellation, and
the Trustee shall execute, authenticate and deliver, to each beneficial owner
identified by DTC in exchange for its beneficial interest in such Restricted
Global Certificate or Regulation S Global Certificate, as the case may be, an
equal aggregate principal amount of Restricted Definitive Certificates or
Regulation S Definitive Certificates, as the case may be, of authorized
denominations. None of the Company, the Registrar, the Paying Agent nor the
Trustee shall be liable for any delay in delivery of such instructions and may
conclusively rely on, and shall be protected in relying on, such registration
instructions. Upon the issuance of Definitive Certificates, the Trustee shall
recognize the Person in whose name the Definitive Certificates are registered in
the Register as Certificateholders hereunder. Neither the Company nor the
Trustee shall be liable if the Trustee or the Company is unable to locate a
qualified successor clearing agency.

                  (e) Any Definitive Certificate delivered in exchange for an
interest in the Restricted Global Certificate pursuant to paragraph (b) of this
Section 3.05 shall, except as otherwise provided by paragraph (e) of Section
3.06, bear the Restricted Legend.
<PAGE>   29
                                      -24-


                  (f) Prior to the expiration of the Restricted Period, any
Regulation S Definitive Certificate delivered in exchange for an interest in a
Regulation S Global Certificate pursuant to paragraph (b) of this Section shall
bear the Restricted Legend.

                  (g) The registered holder of any Restricted Global Certificate
or Regulation S Global Certificate may grant proxies and otherwise authorize any
Person, including Agent Members and Persons that may hold interests through
Agent Members, to take any action which a Holder is entitled to take under this
Agreement or the Certificates.

                  Section 3.06. Special Transfer Provisions. Unless and until
(i) an Initial Certificate is sold under an effective Shelf Registration
Statement, or (ii) an Initial Certificate is exchanged for an Exchange
Certificate pursuant to an effective Exchange Offer Registration Statement, in
each case pursuant to the terms of the Registration Rights Agreement, the
following provisions shall apply to such Initial Certificates:

                  (a) Transfers to Non-QIB Institutional Accredited Investors.
         The following provisions shall apply with respect to the registration
         of any proposed transfer of a Certificate to any Institutional
         Accredited Investor which is neither a QIB nor a Non-U.S. Person:

                           (i) The Registrar shall register the transfer of any
                  Certificate, whether or not bearing the Restricted Legend,
                  only if (x) the requested transfer is at least two years after
                  the later of the original issue date of the Certificates and
                  the last date on which such Certificate was held by the
                  Company, the Trustee or any affiliate of any of such Persons
                  or (y) the proposed transferor is an Initial Purchaser who is
                  transferring Certificates purchased under the Certificates
                  Purchase Agreement and the proposed transferee has delivered
                  to the Registrar a letter substantially in the form of Exhibit
                  C hereto and the aggregate principal amount of the
                  Certificates being transferred is at least $100,000. Except as
                  provided in the foregoing clause (y), the Registrar shall not
                  register the transfer of any Certificate to any Institutional
                  Accredited Investor which is neither a QIB nor a Non-U.S.
                  Person.

                           (ii) If the proposed transferor is an Agent Member
                  holding a beneficial interest in a Restricted Global
                  Certificate, upon receipt by the Registrar of (x) the
                  documents, if any, required by paragraph (i) and (y)
                  instructions given in accordance with DTC's and the
                  Registrar's procedures, the Registrar shall reflect on its
                  books and records the date of the transfer and a decrease in
                  the principal amount of such Restricted Global Certificate in
                  an amount equal to the principal amount of the beneficial
                  interest in such Restricted Global Certificate to be
                  transferred, and the Trustee shall execute, authenticate and
                  deliver to the transferor or at its direction, one or more
                  Restricted Definitive Certificates of like tenor and amount.

                  (b) Transfers to QIBs. The following provisions shall apply
         with respect to the registration of any proposed transfer of an Initial
         Certificate to a QIB (excluding Non-U.S. Persons):
<PAGE>   30
                                      -25-


                           (i) If the Certificate to be transferred consists of
                  Restricted Definitive Certificates, or of an interest in any
                  Regulation S Global Certificate during the Restricted Period,
                  the Registrar shall register the transfer if such transfer is
                  being made by a proposed transferor who has checked the box
                  provided for on the form of Initial Certificate stating, or
                  has otherwise advised the Trustee and the Registrar in
                  writing, that the sale has been made in compliance with the
                  provisions of Rule 144A to a transferee who has signed the
                  certification provided for on the form of Initial Certificate
                  stating, or has otherwise advised the Trustee and the
                  Registrar in writing, that it is purchasing the Initial
                  Certificate for its own account or an account with respect to
                  which it exercises sole investment discretion and that it, or
                  the Person on whose behalf it is acting with respect to any
                  such account, is a QIB within the meaning of Rule 144A, and is
                  aware that the sale to it is being made in reliance on Rule
                  144A and acknowledges that it has received such information
                  regarding the Trust and/or the Company as it has requested
                  pursuant to Rule 144A or has determined not to request such
                  information and that it is aware that the transferor is
                  relying upon its foregoing representations in order to claim
                  the exemption from registration provided by Rule 144A.

                           (ii) Upon receipt by the Registrar of the documents
                  required by clause (i) above and instructions given in
                  accordance with DTC's and the Registrar's procedures therefor,
                  the Registrar shall reflect on its books and records the date
                  of such transfer and an increase in the principal amount of a
                  Restricted Global Certificate in an amount equal to the
                  principal amount of the Restricted Definitive Certificates or
                  interests in such Regulation S Global Certificate, as the case
                  may be, being transferred, and the Trustee shall cancel such
                  Definitive Certificates or decrease the amount of such
                  Regulation S Global Certificate so transferred.

                  (c) Transfers of Interests in the Regulation S Global
         Certificate or Regulation S Definitive Certificates. After the
         expiration of the Restricted Period, the Registrar shall register any
         transfer of interests in any Regulation S Global Certificate or
         Regulation S Definitive Certificates without requiring any additional
         certification. Until the expiration of the Restricted Period, interests
         in the Regulation S Global Certificate may only be held through Agent
         Members acting for and on behalf of Euroclear and Cedel.

                  (d) Transfers to Non-U.S. Persons at Any Time. The following
         provisions shall apply with respect to any registration of any transfer
         of an Initial Certificate to a Non-U.S. Person:

                           (i) Prior to the expiration of the Restricted Period,
                  the Registrar shall register any proposed transfer of an
                  Initial Certificate to a Non-U.S. Person upon receipt of a
                  certificate substantially in the form set forth as Exhibit B
                  hereto from the proposed transferor.

                           (ii) After the expiration of the Restricted Period,
                  the Registrar shall register any proposed transfer to any
                  Non-U.S. Person if the Certificate to be transferred is a
                  Restricted Definitive Certificate or an interest in a
                  Restricted
<PAGE>   31
                                      -26-


                  Global Certificate, upon receipt of a certificate
                  substantially in the form of Exhibit B from the proposed
                  transferor. The Registrar shall promptly send a copy of such
                  certificate to the Company.

                           (iii) Upon receipt by the Registrar of (x) the
                  documents, if any, required by clause (ii) and (y)
                  instructions in accordance with DTC's and the Registrar's
                  procedures, the Registrar shall reflect on its books and
                  records the date of such transfer and a decrease in the
                  principal amount of such Restricted Global Certificate in an
                  amount equal to the principal amount of the beneficial
                  interest in such Restricted Global Certificate to be
                  transferred, and, upon receipt by the Registrar of
                  instructions given in accordance with DTC's and the
                  Registrar's procedures, the Registrar shall reflect on its
                  books and records the date and an increase in the principal
                  amount of the Regulation S Global Certificate in an amount
                  equal to the principal amount of the Restricted Definitive
                  Certificate or the Restricted Global Certificate, as the case
                  may be, to be transferred, and the Trustee shall cancel the
                  Definitive Certificate, if any, so transferred or decrease the
                  amount of such Restricted Global Certificate.

                  (e) Restricted Legend. Upon the transfer, exchange or
         replacement of Certificates not bearing the Restricted Legend, the
         Registrar shall deliver Certificates that do not bear the Restricted
         Legend. Upon the transfer, exchange or replacement of Certificates
         bearing the Restricted Legend, the Registrar shall deliver only
         Certificates that bear the Restricted Legend unless either (i) the
         circumstances contemplated by paragraph (d)(ii) of this Section 3.06
         exist or (ii) there is delivered to the Registrar an Opinion of Counsel
         to the effect that neither such legend nor the related restrictions on
         transfer are required in order to maintain compliance with the
         provisions of the Securities Act.

                  (f) General. By acceptance of any Certificate bearing the
         Restricted Legend, each Holder of such a Certificate acknowledges the
         restrictions on transfer of such Certificate set forth in this
         Agreement and agrees that it will transfer such Certificate only as
         provided in this Agreement. The Registrar shall not register a transfer
         of any Certificate unless such transfer complies with the restrictions
         on transfer, if any, of such Certificate set forth in this Agreement.
         In connection with any transfer of Certificates, each Certificateholder
         agrees by its acceptance of the Certificates to furnish the Registrar
         or the Trustee such certifications, legal opinions or other information
         as either of them may reasonably require to confirm that such transfer
         is being made pursuant to an exemption from, or a transaction not
         subject to, the registration requirements of the Securities Act and in
         accordance with the terms and provisions of this Article III; provided
         that the Registrar shall not be required to determine the sufficiency
         of any such certifications, legal opinions or other information.

                  Until such time as no Certificates remain Outstanding, the
Registrar shall retain copies of all letters, notices and other written
communications received pursuant to Section 3.05 or this Section 3.06. The
Trustee, if not the Registrar at such time, shall have the right to inspect and
make copies of all such letters, notices or other written communications at any
reasonable time upon the giving of reasonable written notice to the Registrar.
<PAGE>   32
                                      -27-


                  Section 3.07. Mutilated, Destroyed, Lost or Stolen
Certificates. If (a) any mutilated Certificate is surrendered to the Registrar
or the Registrar receives evidence to its satisfaction of the destruction, loss
or theft of any Certificate and (b) there is delivered to the Registrar and the
Trustee such security, indemnity or bond, as may be required by them to save
each of them harmless, then, in the absence of notice to the Registrar or the
Trustee that such destroyed, lost or stolen Certificate has been acquired by a
protected purchaser, and provided that the requirements of Section 8-405 of the
Uniform Commercial Code in effect in any applicable jurisdiction are met, the
Trustee shall execute, authenticate and deliver, in exchange for or in lieu of
any such mutilated, destroyed, lost or stolen Certificate, a new Certificate or
Certificates, in authorized denominations and of like Fractional Undivided
Interest and bearing a number not contemporaneously outstanding.

                  In connection with the issuance of any new Certificate under
this Section 3.07, the Trustee may require the payment of a sum sufficient to
cover any tax or other governmental charge that may be imposed in relation
thereto and any other expenses (including the fees and expenses of the Trustee
and the Registrar) connected therewith.

                  Any duplicate Certificate issued pursuant to this Section 3.07
shall constitute conclusive evidence of the appropriate Fractional Undivided
Interest in the Trust, as if originally issued, whether or not the lost, stolen
or destroyed Certificate shall be found at any time.

                  The provisions of this Section are exclusive and shall
preclude (to the extent lawful) all other rights and remedies with respect to
the replacement or payment of mutilated, destroyed, lost or stolen Certificates.

                  Section 3.08. Persons Deemed Owners. Prior to due presentment
of a Certificate for registration of transfer, the Trustee, the Registrar and
any Paying Agent may treat the Person in whose name any Certificate is
registered (as of the day of determination) as the owner of such Certificate for
the purpose of receiving distributions pursuant to Article IV and for all other
purposes whatsoever, and none of the Trustee, the Registrar or any Paying Agent
shall be affected by any notice to the contrary.

                  Section 3.09. Cancellation. All Certificates surrendered for
payment or transfer or exchange shall, if surrendered to the Trustee or any
agent of the Trustee other than the Registrar, be delivered to the Registrar for
cancellation and shall promptly be canceled by it. No Certificates shall be
authenticated in lieu of or in exchange for any Certificates canceled as
provided in this Section, except as expressly permitted by this Agreement. All
canceled Certificates held by the Registrar shall be destroyed and a
certification of their destruction delivered to the Trustee.

                  Section 3.10. Temporary Certificates. Until definitive
Certificates are ready for delivery, the Trustee shall authenticate temporary
Certificates. Temporary Certificates shall be substantially in the form of
definitive Certificates but may have insertions, substitutions, omissions and
other variations determined to be appropriate by the officers executing the
temporary Certificates, as evidenced by their execution of such temporary
Certificates. If temporary Certificates are issued, the Trustee will cause
definitive Certificates to be prepared without unreasonable delay. After the
preparation of definitive Certificates, the temporary
<PAGE>   33
                                      -28-


Certificates shall be exchangeable for definitive Certificates upon surrender of
the temporary Certificates at the office or agency of the Trustee designated for
such purpose pursuant to Section 7.12, without charge to the Certificateholder.
Upon surrender for cancellation of any one or more temporary Certificates, the
Trustee shall execute, authenticate and deliver in exchange therefor a like face
amount of definitive Certificates of authorized denominations. Until so
exchanged, the temporary Certificates shall be entitled to the same benefits
under this Agreement as definitive Certificates.

                  Section 3.11. Limitation of Liability for Payments. All
payments and distributions made to Certificateholders in respect of the
Certificates shall be made only from the Trust Property and only to the extent
that the Trustee shall have sufficient income or proceeds from the Trust
Property to make such payments in accordance with the terms of Article IV of
this Agreement. Each Certificateholder, by its acceptance of a Certificate,
agrees that it will look solely to the income and proceeds from the Trust
Property for any payment or distribution due to such Certificateholder pursuant
to the terms of this Agreement and that it will not have any recourse to the
Company, the Trustee, the Loan Trustees, the Liquidity Provider, the Owner
Trustees or the Owner Participants, except as otherwise expressly provided
herein or in the Intercreditor Agreement.

                  The Company is a party to this Agreement solely for purposes
of meeting the requirements of the Trust Indenture Act, and therefore shall not
have any right, obligation or liability hereunder (except as otherwise expressly
provided herein).

                  Section 3.12 ERISA Restrictive Legend. All Certificates issued
pursuant to this Agreement shall bear a legend to the following effect (the
"ERISA Legend") unless the Company and the Trustee determine otherwise
consistent with applicable law:

                  "BY ITS ACQUISITION HEREOF, THE HOLDER REPRESENTS THAT (A) NO
PLAN ASSETS HAVE BEEN USED TO PURCHASE THIS CERTIFICATE OR AN INTEREST HEREIN OR
(B) THE PURCHASE AND HOLDING OF THIS CERTIFICATE OR AN INTEREST HEREIN IS EXEMPT
FROM THE PROHIBITED TRANSACTION RESTRICTIONS OF ERISA AND THE CODE PURSUANT TO
ONE OR MORE PROHIBITED TRANSACTION STATUTORY OR ADMINISTRATIVE EXEMPTIONS. THE
PASS THROUGH TRUST AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO
REFUSE TO REGISTER ANY TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE
FOREGOING RESTRICTIONS."

                  By acceptance of any Certificate bearing the ERISA Legend,
each Holder of such a Certificate acknowledges the restrictions on transfer of
such Certificate set forth in this Agreement and agrees that it will transfer
such Certificate only as provided in this Agreement. The Trustee shall not
register a transfer of any Certificate unless such transfer complies with the
restrictions on transfer, if any, of such Certificate set forth in such legend.
<PAGE>   34
                                      -29-


                                   ARTICLE IV

                          DISTRIBUTIONS; STATEMENTS TO
                               CERTIFICATEHOLDERS

                  Section 4.01. Certificate Account and Special Payments
Account. (a) The Trustee shall establish and maintain on behalf of the
Certificateholders a Certificate Account as one or more non-interest-bearing
accounts. The Trustee shall hold the Certificate Account in trust for the
benefit of the Certificateholders, and shall make or permit withdrawals
therefrom only as provided in this Agreement. On each day when a Scheduled
Payment is made to the Trustee under the Intercreditor Agreement, the Trustee
upon receipt thereof shall immediately deposit the aggregate amount of such
Scheduled Payment in the Certificate Account.

                  (b) The Trustee shall establish and maintain on behalf of the
Certificateholders a Special Payments Account as one or more accounts, which
shall be non-interest bearing except as provided in Section 4.04. The Trustee
shall hold the Special Payments Account in trust for the benefit of the
Certificateholders and shall make or permit withdrawals therefrom only as
provided in this Agreement. On each day when one or more Special Payments are
made to the Trustee under the Intercreditor Agreement and upon the payment of
the Special Redemption Premium to the Trustee under the Note Purchase Agreement,
the Trustee, upon receipt thereof, shall immediately deposit the aggregate
amount of such Special Payments in the Special Payments Account.

                  (c) The Trustee shall cause the Subordination Agent to present
to the related Loan Trustee of each Equipment Note such Equipment Note on the
date of its stated final maturity or, in the case of any Equipment Note which is
to be redeemed in whole pursuant to the related Indenture, on the applicable
redemption date under such Indenture.

                  Section 4.02. Distributions from Certificate Account and
Special Payments Account. (a) On each Regular Distribution Date or as soon
thereafter as the Trustee has confirmed receipt of the payment of all or any
part of the Scheduled Payments due on such date, the Trustee shall distribute
out of the Certificate Account the entire amount deposited therein pursuant to
Section 4.01(a). There shall be so distributed to each Certificateholder of
record on the Record Date with respect to such Regular Distribution Date (other
than as provided in Section 11.01 concerning the final distribution) by check
mailed to such Certificateholder, at the address appearing in the Register, such
Certificateholder's pro rata share (based on the Fractional Undivided Interest
in the Trust held by such Certificateholder) of the total amount in the
Certificate Account, except that, with respect to Certificates registered on the
Record Date in the name of DTC, such distribution shall be made by wire transfer
in immediately available funds to the account designated by DTC.

                  (b) On each Special Distribution Date with respect to any
Special Payment or as soon thereafter as the Trustee has confirmed receipt of
any Special Payments due on the Equipment Notes held in the related Trust or
realized upon the sale of such Equipment Notes or receipt of the Special
Redemption Premium, the Trustee shall distribute out of the Special Payments
Account the entire amount of such Special Payment deposited therein pursuant to
Section 4.01(b). There shall be so distributed to each Certificateholder of
record on the Record
<PAGE>   35
                                      -30-


Date with respect to such Special Distribution Date (other than as provided in
Section 11.01 concerning the final distribution) by check mailed to such
Certificateholder, at the address appearing in the Register, such
Certificateholder's pro rata share (based on the Fractional Undivided Interest
in the Trust held by such Certificateholder) of the total amount in the Special
Payments Account on account of such Special Payment, except that, with respect
to Certificates registered on the Record Date in the name of DTC, such
distribution shall be made by wire transfer in immediately available funds to
the account designated by DTC.

                  (c) The Trustee shall cause notice of each Special Payment to
be mailed to each Certificateholder at his address as it appears in the
Register. In the event of redemption or purchase of Equipment Notes held in the
Trust, such notice shall be mailed not less than 20 days prior to the Special
Distribution Date for the Special Payment resulting from such redemption or
purchase, which Special Distribution Date shall be the date of such redemption
or purchase. In the event of the payment of a Special Redemption Premium by the
Company to the Trustee under the Note Purchase Agreement, such notice shall be
mailed, together with the notice by the Escrow Paying Agent under Section 2.06
of the Escrow Agreement, not less than 20 days prior to the Special Distribution
Date for such amount, which Special Distribution Date shall be the Final
Withdrawal Date. In the case of any other Special Payments, such notice shall be
mailed as soon as practicable after the Trustee has confirmed that it has
received funds for such Special Payment, stating the Special Distribution Date
for such Special Payment which shall occur not less than 20 days after the date
of such notice and as soon as practicable thereafter. Notices mailed by the
Trustee shall set forth:

                  (i) the Special Distribution Date and the Record Date therefor
         (except as otherwise provided in Section 11.01),

                  (ii) the amount of the Special Payment for each $1,000 face
         amount Certificate and the amount thereof constituting principal,
         premium, if any, and interest,

                  (iii) the reason for the Special Payment, and

                  (iv) if the Special Distribution Date is the same date as a
         Regular Distribution Date, the total amount to be received on such date
         for each $1,000 face amount Certificate.

If the amount of (i) premium, if any, payable upon the redemption or purchase of
an Equipment Note or (ii) the Special Redemption Premium, if any, has not been
calculated at the time that the Trustee mails notice of a Special Payment, it
shall be sufficient if the notice sets forth the other amounts to be distributed
and states that any premium received will also be distributed.

                  If any redemption of the Equipment Notes held in the Trust is
canceled, the Trustee, as soon as possible after learning thereof, shall cause
notice thereof to be mailed to each Certificateholder at its address as it
appears on the Register.

                  Section 4.03. Statements to Certificateholders. (a) On each
Distribution Date, the Trustee will include with each distribution to
Certificateholders of a Scheduled Payment or Special Payment, as the case may
be, a statement setting forth the information provided below (in the case of a
Special Payment, including any Special Redemption Premium, reflecting in part
<PAGE>   36
                                      -31-


the information provided by the Escrow Paying Agent under the Escrow Agreement).
Such statement shall set forth (per $1,000 face amount Certificate as to (ii),
(iii), (iv) and (v) below) the following information:

                  (i) the aggregate amount of funds distributed on such
         Distribution Date hereunder and under the Escrow Agreement, indicating
         the amount allocable to each source;

                  (ii) the amount of such distribution hereunder allocable to
         principal and the amount allocable to premium (including the Special
         Redemption Premium), if any;

                  (iii) the amount of such distribution hereunder allocable to
         interest; and

                  (iv) the amount of such distribution under the Escrow
         Agreement allocable to interest;

                  (v) the amount of such distribution under the Escrow Agreement
         allocable to Deposits; and

                  (vi) the Pool Balance and the Pool Factor.

                  With respect to the Certificates registered in the name of
DTC, on the Record Date prior to each Distribution Date, the Trustee will
request from DTC a securities position listing setting forth the names of all
Agent Members reflected on DTC's books as holding interests in the Certificates
on such Record Date. On each Distribution Date, the Trustee will mail to each
such Agent Member the statement described above and will make available
additional copies as requested by such Agent Member for forwarding to holders of
interests in the Certificates.

                  (b) Within a reasonable period of time after the end of each
calendar year but not later than the latest date permitted by law, the Trustee
shall furnish to each Person who at any time during such calendar year was a
Certificateholder of record a statement containing the sum of the amounts
determined pursuant to clauses (a)(i), (a)(ii), (a)(iii), (a)(iv) and (a)(v)
above for such calendar year or, in the event such Person was a
Certificateholder of record during a portion of such calendar year, for such
portion of such year, and such other items as are readily available to the
Trustee and which a Certificateholder shall reasonably request as necessary for
the purpose of such Certificateholder's preparation of its federal income tax
returns. Such statement and such other items shall be prepared on the basis of
information supplied to the Trustee by the Agent Members and shall be delivered
by the Trustee to such Agent Members to be available for forwarding by such
Agent Members to the holders of interests in the Certificates in the manner
described in Section 4.03(a).

                  (c) Promptly following (i) the Delivery Period Termination
Date, if there has been any change in the information set forth in clauses (x),
(y) and (z) below from that set forth in page 69 of the Offering Circular, and
(ii) any early redemption or purchase of, or any default in the payment of
principal or interest in respect of, any of the Equipment Notes held in the
Trust, or any Final Withdrawal, the Trustee shall furnish to Certificateholders
of record on such date a statement setting forth (x) the expected Pool Balances
for each subsequent Regular Distribution Date following the Delivery Period
Termination Date, (y) the related Pool Factors
<PAGE>   37
                                      -32-


for such Regular Distribution Dates and (z) the expected principal distribution
schedule of the Equipment Notes, in the aggregate, held as Trust Property at the
date of such notice. With respect to the Certificates registered in the name of
DTC, on the Delivery Period Termination Date, the Trustee will request from DTC
a securities position listing setting forth the names of all Agent Members
reflected on DTC's books as holding interests in the Certificates on such date.
The Trustee will mail to each such Agent Member the statement described above
and will make available additional copies as requested by such Agent Member for
forwarding to holders of interests in the Certificates.

                  Section 4.04. Investment of Special Payment Moneys. Any money
received by the Trustee pursuant to Section 4.01(b) representing a Special
Payment which is not distributed on the date received shall, to the extent
practicable, be invested in Permitted Investments by the Trustee pending
distribution of such Special Payment pursuant to Section 4.02. Any investment
made pursuant to this Section 4.04 shall be in such Permitted Investments having
maturities not later than the date that such moneys are required to be used to
make the payment required under Section 4.02 on the applicable Special
Distribution Date and the Trustee shall hold any such Permitted Investments
until maturity. The Trustee shall have no liability with respect to any
investment made pursuant to this Section 4.04, other than by reason of the
willful misconduct or negligence of the Trustee. All income and earnings from
such investments shall be distributed on such Special Distribution Date as part
of such Special Payment.

                                    ARTICLE V

                                   THE COMPANY

                  Section 5.01. Maintenance of Corporate Existence. The Company,
at its own cost and expense, will do or cause to be done all things necessary to
preserve and keep in full force and effect its corporate existence, except as
permitted by Section 5.02.

                  Section 5.02. Consolidation, Merger, etc. The Company shall
not consolidate with or merge into any other corporation or convey, transfer or
lease substantially all of its assets as an entirety to any Person unless:

                  (a) the corporation formed by such consolidation or into which
         the Company is merged or the Person that acquires by conveyance,
         transfer or lease substantially all of the assets of the Company as an
         entirety shall be (i) organized and validly existing under the laws of
         the United States of America or any state thereof or the District of
         Columbia, (ii) a "citizen of the United States" as defined in 49 U.S.C.
         40102(a)(15), as amended, and (iii) a United States certificated air
         carrier, if and so long as such status is a condition of entitlement to
         the benefits of Section 1110 of the Bankruptcy Reform Act of 1978, as
         amended (11 U.S.C. Section 1110);

                  (b) the corporation formed by such consolidation or into which
         the Company is merged or the Person which acquires by conveyance,
         transfer or lease substantially all of the assets of the Company as an
         entirety shall execute and deliver to the Trustee a duly authorized,
         valid, binding and enforceable agreement in form and substance
         reasonably satisfactory to the Trustee containing an assumption by such
         successor corporation or
<PAGE>   38
                                      -33-


         Person of the due and punctual performance and observance of each
         covenant and condition of this Agreement, the Other Pass Through Trust
         Agreements and each Financing Document to be performed or observed by
         the Company; and

                  (c) the Company shall have delivered to the Trustee an
         Officer's Certificate of the Company reasonably satisfactory to the
         Trustee, stating that such consolidation, merger, conveyance, transfer
         or lease and the assumption agreement mentioned in clause (b) above
         comply with this Section 5.02 and that all conditions precedent herein
         provided for relating to such transaction have been complied with.

                  Upon any consolidation or merger, or any conveyance, transfer
or lease of substantially all of the assets of the Company as an entirety in
accordance with this Section 5.02, the successor corporation or Person formed by
such consolidation or into which the Company is merged or to which such
conveyance, transfer or lease is made shall succeed to, and be substituted for,
and may exercise every right and power of, the Company under this Agreement with
the same effect as if such successor corporation or Person had been named as the
Company herein. No such conveyance, transfer or lease of substantially all of
the assets of the Company as an entirety shall have the effect of releasing any
successor corporation or Person which shall have become such in the manner
prescribed in this Section 5.02 from its liability in respect of this Agreement
and any Financing Document to which it is a party.

                                   ARTICLE VI

                                     DEFAULT

                  Section 6.01. Events of Default. (a) Exercise of Remedies.
Upon the occurrence and during the continuation of any Indenture Default under
any Indenture, the Trustee may, to the extent it is the Controlling Party at
such time (as determined pursuant to the Intercreditor Agreement), direct the
exercise of remedies as provided in the Intercreditor Agreement.

                  (b) Purchase Rights of Certificateholders. (i) At any time
         after the occurrence and during the continuance of a Triggering Event,
         each Certificateholder shall have the right to purchase, for the
         purchase price set forth in the Class A Trust Agreement, all, but not
         less than all, of the Class A Certificates upon ten days' written
         notice to the Class A Trustee and each other Certificateholder,
         provided that (i) if prior to the end of such ten-day period any other
         Certificateholder notifies such purchasing Certificateholder that such
         other Certificateholder wants to participate in such purchase, then
         such other Certificateholder may join with the purchasing
         Certificateholder to purchase all, but not less than all, of the Class
         A Certificates pro rata based on the Fractional Undivided Interest in
         the Trust held by each such Certificateholder and (ii) if prior to the
         end of such ten-day period any other Certificateholder fails to notify
         the purchasing Certificateholder of such other Certificateholder's
         desire to participate in such a purchase, then such other
         Certificateholder shall lose its right to purchase the Class A
         Certificates pursuant to this Section 6.01(b); and

                  (ii) by acceptance of its Certificate, each Certificateholder
         agrees that at any time after the occurrence and during the
         continuation of a Triggering Event,
<PAGE>   39
                                      -34-


                           (A) each Class C Certificateholder shall have the
                  right (which shall not expire upon any purchase of the Class A
                  Certificates pursuant to clause (b)(i) above) to purchase all,
                  but not less than all, of the Class A Certificates and the
                  Certificates upon ten days' written notice to the Class A
                  Trustee, the Trustee and each other Class C Certificateholder,
                  provided that (1) if prior to the end of such ten-day period
                  any other Class C Certificateholder notifies such purchasing
                  Class C Certificateholder that such other Class C
                  Certificateholder wants to participate in such purchase, then
                  such other Class C Certificateholder may join with the
                  purchasing Class C Certificateholder to purchase all, but not
                  less than all, of the Class A Certificates and the
                  Certificates pro rata based on the Fractional Undivided
                  Interest in the Class C Trust, taken as a whole, held by each
                  such Class C Certificateholder and (2) if prior to the end of
                  such ten-day period any other Class C Certificateholder fails
                  to notify the purchasing Class C Certificateholder of such
                  other Class C Certificateholder's desire to participate in
                  such a purchase, then such other Class C Certificateholder
                  shall lose its right to purchase the Certificates pursuant to
                  this Section 6.01(b); and

                           (B) each Class D Certificateholder shall have the
                  right (which shall not expire upon any purchase of the Class A
                  Certificates pursuant to clause (b)(i) above or any purchase
                  of the Class A Certificates and the Certificates pursuant to
                  clause (b)(ii)(A) above) to purchase all, but not less than
                  all, of the Class A Certificates, the Certificates and the
                  Class C Certificates upon ten days' written notice to the
                  Class A Trustee, the Trustee, the Class C Trustee and each
                  other Class D Certificateholder, provided that (1) if prior to
                  the end of such ten-day period any other Class D
                  Certificateholder notifies such purchasing Class D
                  Certificateholder that such other Class D Certificateholder
                  wants to participate in such purchase, then such other Class D
                  Certificateholder may join with the purchasing Class D
                  Certificateholder to purchase all, but not less than all, of
                  the Class A Certificates, the Certificates and the Class C
                  Certificates pro rata based on the Fractional Undivided
                  Interest in the Class D Trust, taken as a whole, held by each
                  such Class D Certificateholder and (2) if prior to the end of
                  such ten day period any other Class D Certificateholder fails
                  to notify the purchasing Class D Certificateholder of such
                  other Class D Certificateholder's desire to participate in
                  such a purchase, then such other Class D Certificateholder
                  shall lose its right to purchase the Certificates pursuant to
                  this Section 6.01(b).

                  The purchase price with respect to the Certificates shall be
equal to the Pool Balance of the Certificates, together with accrued and unpaid
interest thereon to the date of such purchase, without premium, but including
any other amounts then due and payable to the Certificateholders under this
Agreement, the Intercreditor Agreement, the Escrow Agreement or any Financing
Document or on or in respect of the Certificates; provided, however, that (i) if
such purchase occurs after the record date specified in Section 2.03(b) of the
Escrow Agreement relating to the distribution of unused Deposits and accrued and
unpaid interest thereunder, such purchase price shall be reduced by the
aggregate amount of unused Deposits and interest to be distributed under the
Escrow Agreement (which deducted amounts shall remain distributable to, and may
be retained by, the Certificateholder as of such Record Date) and (ii) if such
purchase occurs after a Record Date, such purchase price shall be reduced by the
amount to be distributed
<PAGE>   40
                                      -35-


hereunder on the related Distribution Date (which deducted amounts shall remain
distributable to, and may be retained by, the Certificateholder as of such
Record Date); provided, further, that no such purchase of Certificates shall be
effective unless the purchaser(s) shall certify to the Trustee that
contemporaneously with such purchase, such purchaser(s) is purchasing, pursuant
to the terms of this Agreement and the Other Pass Through Trust Agreements, the
Class A Certificates, the Certificates and the Class C Certificates which are
senior to the securities held by such purchaser(s). Each payment of the purchase
price of the Certificates referred to in the first sentence hereof shall be made
to an account or accounts designated by the Trustee and each such purchase shall
be subject to the terms of this Section 6.01(b). Each Certificateholder agrees
by its acceptance of its Certificate that it will, subject to Section 3.04
hereof, upon payment from such Class C Certificateholder(s) or Class D
Certificateholder(s), as the case may be, of the purchase price set forth in the
first sentence of this paragraph, forthwith sell, assign, transfer and convey to
the purchaser(s) thereof (without recourse, representation or warranty of any
kind except for its own acts), all of the right, title, interest and obligation
of such Certificateholder in this Agreement, the Escrow Agreement, the Deposit
Agreement, the Intercreditor Agreement, the Liquidity Facility, the Financing
Documents and all Certificates and Escrow Receipts held by such
Certificateholder (excluding all right, title and interest under any of the
foregoing to the extent such right, title or interest is with respect to an
obligation not then due and payable as respects any action or inaction or state
of affairs occurring prior to such sale) and the purchaser shall assume all of
such Certificateholder's obligations under this Agreement, the Escrow Agreement,
the Deposit Agreement, the Intercreditor Agreement, the Liquidity Facility, the
Financing Documents and all such Certificates and Escrow Receipts. The
Certificates will be deemed to be purchased on the date payment of the purchase
price is made notwithstanding the failure of the Certificateholders to deliver
any Certificates (whether in the form of Definitive Certificates or beneficial
interests in Global Certificates) and, upon such a purchase, (i) the only rights
of the Certificateholders will be to deliver the Certificates to the
purchaser(s) and receive the purchase price for such Certificates and (ii) if
the purchaser(s) shall so request, such Certificateholder will comply with all
the provisions of Section 3.04 hereof to enable new Certificates to be issued to
the purchaser in such denominations as it shall request. All charges and
expenses in connection with the issuance of any such new Certificates shall be
borne by the purchaser thereof.

                  As used in this Section 6.01(b), the terms "Class A
Certificate", "Class A Certificateholder", "Class A Trust", "Class A Trust
Agreement", "Class A Trustee", "Class C Certificate", "Class C
Certificateholder", "Class C Trust", "Class C Trustee", "Class D Certificate",
and "Class D Trust", shall have the respective meanings assigned to such terms
in the Intercreditor Agreement.

                  Section 6.02. Incidents of Sale of Equipment Notes. Upon any
sale of all or any part of the Equipment Notes made either under the power of
sale given under this Agreement or otherwise for the enforcement of this
Agreement, the following shall be applicable:

                  (1) Certificateholders and Trustee May Purchase Equipment
         Notes. Any Certificateholder, the Trustee in its individual or any
         other capacity or any other Person may bid for and purchase any of the
         Equipment Notes, and upon compliance with the terms of sale, may hold,
         retain, possess and dispose of such Equipment Notes in their own
         absolute right without further accountability.
<PAGE>   41
                                      -36-


                  (2) Receipt of Trustee Shall Discharge Purchaser. The receipt
         of the Trustee making such sale shall be a sufficient discharge to any
         purchaser for his purchase money, and, after paying such purchase money
         and receiving such receipt, such purchaser or its personal
         representative or assigns shall not be obliged to see to the
         application of such purchase money, or be in any way answerable for any
         loss, misapplication or non-application thereof.

                  (3) Application of Moneys Received upon Sale. Any moneys
         collected by the Trustee upon any sale made either under the power of
         sale given by this Agreement or otherwise for the enforcement of this
         Agreement shall be applied as provided in Section 4.02.

                  Section 6.03. Judicial Proceedings Instituted by Trustee;
Trustee May Bring Suit. If there shall be a failure to make payment of the
principal of, premium, if any, or interest on any Equipment Note, or if there
shall be any failure to pay Rent (as defined in the relevant Lease) under any
Lease when due and payable, then the Trustee, in its own name and as trustee of
an express trust, as holder of such Equipment Notes, to the extent permitted by
and in accordance with the terms of the Intercreditor Agreement and the
Financing Documents (subject to the rights of the applicable Owner Trustee or
Owner Participant to cure any such failure to pay principal of, premium, if any,
or interest on any Equipment Note or to pay Rent under any Lease in accordance
with the applicable Indenture), shall be entitled and empowered to institute any
suits, actions or proceedings at law, in equity or otherwise, for the collection
of the sums so due and unpaid on such Equipment Notes or under such Lease and
may prosecute any such claim or proceeding to judgment or final decree with
respect to the whole amount of any such sums so due and unpaid.

                  Section 6.04 Control by Certificateholders. Subject to Section
6.03 and the Intercreditor Agreement, the Certificateholders holding
Certificates evidencing Fractional Undivided Interests aggregating not less than
a majority in interest in the Trust shall have the right to direct the time,
method and place of conducting any proceeding for any remedy available to the
Trustee with respect to the Trust or pursuant to the terms of the Intercreditor
Agreement, or exercising any trust or power conferred on the Trustee under this
Agreement or the Intercreditor Agreement, including any right of the Trustee as
Controlling Party under the Intercreditor Agreement or as holder of the
Equipment Notes, provided that:

                  (1) such Direction shall not be in conflict with any rule of
         law or with this Agreement and would not involve the Trustee in
         personal liability or expense,

                  (2) the Trustee shall not determine that the action so
         directed would be unjustly prejudicial to the Certificateholders not
         taking part in such Direction, and

                  (3) the Trustee may take any other action deemed proper by the
         Trustee which is not inconsistent with such Direction.

                  Section 6.05. Waiver of Past Defaults. Subject to the
Intercreditor Agreement, the Certificateholders holding Certificates evidencing
Fractional Undivided Interests aggregating not less than a majority in interest
in the Trust (i) may on behalf of all of the Certificateholders
<PAGE>   42
                                      -37-


waive any past Event of Default hereunder and its consequences or (ii) if the
Trustee is the Controlling Party, may direct the Trustee to instruct the
applicable Loan Trustee to waive any past Indenture Default under any Indenture
and its consequences, and thereby annul any Direction given by such
Certificateholders or the Trustee to such Loan Trustee with respect thereto,
except a default:

                  (1) in the deposit of any Scheduled Payment or Special Payment
         under Section 4.01 or in the distribution of any payment under Section
         4.02 on the Certificates, or

                  (2) in the payment of the principal of (premium, if any) or
         interest on the Equipment Notes, or

                  (3) in respect of a covenant or provision hereof which under
         Article IX cannot be modified or amended without the consent of each
         Certificateholder holding an Outstanding Certificate affected thereby.

                  Upon any such waiver, such default shall cease to exist with
respect to the Certificates and any Event of Default arising therefrom shall be
deemed to have been cured for every purpose and any direction given by the
Trustee on behalf of the Certificateholders to the relevant Loan Trustee shall
be annulled with respect thereto; but no such waiver shall extend to any
subsequent or other default or Event of Default or impair any right consequent
thereon. Upon any such waiver, the Trustee shall vote the Equipment Notes issued
under the relevant Indenture to waive the corresponding Indenture Default.

                  Section 6.06. Right of Certificateholders to Receive Payments
Not to Be Impaired. Anything in this Agreement to the contrary notwithstanding,
including, without limitation, Section 6.07 hereof, but subject to the
Intercreditor Agreement, the right of any Certificateholder to receive
distributions of payments required pursuant to Section 4.02 hereof on the
Certificates when due, or to institute suit for the enforcement of any such
payment on or after the applicable Regular Distribution Date or Special
Distribution Date, shall not be impaired or affected without the consent of such
Certificateholder.

                  Section 6.07. Certificateholders May Not Bring Suit Except
Under Certain Conditions. A Certificateholder shall not have the right to
institute any suit, action or proceeding at law or in equity or otherwise with
respect to this Agreement, for the appointment of a receiver or for the
enforcement of any other remedy under this Agreement, unless:

                  (1) such Certificateholder previously shall have given written
         notice to the Trustee of a continuing Event of Default;

                  (2) Certificateholders holding Certificates evidencing
         Fractional Undivided Interests aggregating not less than 25% of the
         Trust shall have requested the Trustee in writing to institute such
         action, suit or proceeding and shall have offered to the Trustee
         indemnity as provided in Section 7.03(e);

                  (3) the Trustee shall have refused or neglected to institute
         such an action, suit or proceeding for 60 days after receipt of such
         notice, request and offer of indemnity; and
<PAGE>   43
                                      -38-


                  (4) no direction inconsistent with such written request shall
         have been given to the Trustee during such 60-day period by
         Certificateholders holding Certificates evidencing Fractional Undivided
         Interests aggregating not less than a majority in interest in the
         Trust.

                  It is understood and intended that no one or more of the
Certificateholders shall have any right in any manner whatsoever hereunder or
under the Certificates to (i) surrender, impair, waive, affect, disturb or
prejudice any property in the Trust Property or the lien of any Indenture on any
property subject thereto, or the rights of the Certificateholders or the holders
of the Equipment Notes, (ii) obtain or seek to obtain priority over or
preference with respect to any other such Certificateholder or (iii) enforce any
right under this Agreement, except in the manner herein provided and for the
equal, ratable and common benefit of all the Certificateholders subject to the
provisions of this Agreement.

                  Section 6.08. Remedies Cumulative. Every remedy given
hereunder to the Trustee or to any of the Certificateholders shall not be
exclusive of any other remedy or remedies, and every such remedy shall be
cumulative and in addition to every other remedy given hereunder or now or
hereafter given by statute, law, equity or otherwise.

                                   ARTICLE VII

                                   THE TRUSTEE

                  Section 7.01. Certain Duties and Responsibilities. (a) Except
during the continuance of an Event of Default, the Trustee undertakes to perform
such duties as are specifically set forth in this Agreement, and no implied
covenants or obligations shall be read into this Agreement against the Trustee.

                  (b) In case an Event of Default has occurred and is
continuing, the Trustee shall exercise such of the rights and powers vested in
it by this Agreement, and use the same degree of care and skill in their
exercise, as a prudent man would exercise or use under the circumstances in the
conduct of its own affairs.

                  (c) No provision of this Agreement shall be construed to
relieve the Trustee from liability for its own negligent action, its own
negligent failure to act, or its own willful misconduct, except that

                  (1) this SubSection shall not be construed to limit the effect
         of SubSection (a) of this Section; and

                  (2) the Trustee shall not be liable for any error of judgment
         made in good faith by a Responsible Officer of the Trustee, unless it
         shall be proved that the Trustee was negligent in ascertaining the
         pertinent facts.

                  (d) Whether or not herein expressly so provided, every
provision of this Trust Agreement relating to the conduct or affecting the
liability of or affording protection to the Trustee shall be subject to the
provisions of this Section.
<PAGE>   44
                                      -39-


                  Section 7.02. Notice of Defaults. As promptly as practicable
after, and in any event within 90 days after, the occurrence of any default (as
such term is defined below) hereunder, the Trustee shall transmit by mail to the
Company, the Owner Trustees, the Owner Participants, the Loan Trustees and the
Certificateholders in accordance with Section 313(c) of the Trust Indenture Act,
notice of such default hereunder known to the Trustee, unless such default shall
have been cured or waived; provided, however, that, except in the case of a
default on the payment of the principal, premium, if any, or interest on any
Equipment Note held in the Trust, the Trustee shall be protected in withholding
such notice if and so long as the board of directors, the executive committee or
a trust committee of directors and/or Responsible Officers of the Trustee in
good faith determine that the withholding of such notice is in the interests of
the Certificateholders. For the purpose of this Section, the term "default"
means any event that is, or after notice or lapse of time or both would become,
an Event of Default.

                  Section 7.03. Certain Rights of Trustee. Subject to the
provisions of Section 315 of the Trust Indenture Act:

                  (a) the Trustee may rely and shall be protected in acting or
         refraining from acting in reliance upon any resolution, certificate,
         statement, instrument, opinion, report, notice, request, direction,
         consent, order, bond, debenture or other paper or document believed by
         it to be genuine and to have been signed or presented by the proper
         party or parties;

                  (b) any request or direction of the Company mentioned herein
         shall be sufficiently evidenced by a written description of the subject
         matter thereof accompanied by an Officer's Certificate and an Opinion
         of Counsel as provided in Section 1.02 of this Agreement;

                  (c) whenever in the administration of this Agreement the
         Trustee shall deem it desirable that a matter be proved or established
         prior to taking, suffering or omitting any action hereunder, the
         Trustee (unless other evidence be herein specifically prescribed) may,
         in the absence of bad faith on its part, rely upon an Officer's
         Certificate of the Company, any Owner Trustee or any Loan Trustee;

                  (d) the Trustee may consult with counsel and the advice of
         such counsel or any Opinion of Counsel shall be full and complete
         authorization and protection in respect of any action taken, suffered
         or omitted by it hereunder in good faith and in reliance thereon;

                  (e) the Trustee shall be under no obligation to exercise any
         of the rights or powers vested in it by this Agreement at the Direction
         of any of the Certificateholders pursuant to this Agreement, unless
         such Certificateholders shall have offered to the Trustee reasonable
         security or indemnity against the cost, expenses and liabilities which
         might be incurred by it in compliance with such Direction;

                  (f) the Trustee shall not be bound to make any investigation
         into the facts or matters stated in any resolution, certificate,
         statement, instrument, opinion, report, notice, request, direction,
         consent, order, bond, debenture or other paper or document;
<PAGE>   45
                                      -40-


                  (g) the Trustee may execute any of the trusts or powers under
         this Agreement or perform any duties under this Agreement either
         directly or by or through agents or attorneys, and the Trustee shall
         not be responsible for any misconduct or negligence on the part of any
         agent or attorney appointed with due care by it under this Agreement;

                  (h) the Trustee shall not be liable with respect to any action
         taken or omitted to be taken by it in good faith in accordance with the
         Direction of the Certificateholders holding Certificates evidencing
         Fractional Undivided Interests aggregating not less than a majority in
         interest in the Trust relating to the time, method and place of
         conducting any proceeding for any remedy available to the Trustee, or
         exercising any trust or power conferred upon the Trustee, under this
         Agreement; and

                  (i) the Trustee shall not be required to expend or risk its
         own funds in the performance of any of its duties under this Agreement,
         or in the exercise of any of its rights or powers, if it shall have
         reasonable grounds for believing that repayment of such funds or
         adequate indemnity against such risk is not reasonably assured to it.

                  Section 7.04. Not Responsible for Recitals or Issuance of
Certificates. The recitals contained herein and in the Certificates, except the
certificates of authentication, shall not be taken as the statements of the
Trustee, and the Trustee assumes no responsibility for their correctness.
Subject to Section 7.15, the Trustee makes no representations as to the validity
or sufficiency of this Agreement, any Equipment Notes, the Intercreditor
Agreement, the Deposit Agreement, the Escrow Agreement, the Certificates or any
other Financing Document, except that the Trustee hereby represents and warrants
that this Agreement has been, and the Intercreditor Agreement, the Registration
Rights Agreement, the Note Purchase Agreement, the Escrow Agreement and each
Certificate will be, executed, authenticated and delivered by one of its
officers who is duly authorized to execute, authenticate and deliver such
document on its behalf.

                  Section 7.05. May Hold Certificates. The Trustee, any Paying
Agent, Registrar or any of their Affiliates or any other agent in their
respective individual or any other capacity may become the owner or pledgee of
Certificates and, subject to Sections 310(b) and 311 of the Trust Indenture Act,
if applicable, may otherwise deal with the Company, the Owner Trustees or the
Loan Trustees with the same rights it would have if it were not Trustee, Paying
Agent, Registrar or such other agent.

                  Section 7.06. Money Held in Trust. Money held by the Trustee
or the Paying Agent in trust hereunder need not be segregated from other funds
except to the extent required herein or by law and neither the Trustee nor the
Paying Agent shall have any liability for interest upon any such moneys except
as provided for herein.

                  Section 7.07. Compensation and Reimbursement. The Company
agrees:

                  (1) to pay, or cause to be paid, to the Trustee from time to
         time reasonable compensation for all services rendered by it hereunder
         as set forth in a written fee letter dated the date hereof between the
         Company and the Trustee, which letter is incorporated
<PAGE>   46
                                      -41-


         herein by reference (which compensation shall not be limited by any
         provision of law in regard to the compensation of a trustee of an
         express trust);

                  (2) except as otherwise expressly provided herein, to
         reimburse, or cause to be reimbursed, the Trustee upon its request for
         all reasonable out-of-pocket expenses, disbursements and advances
         incurred or made by the Trustee in accordance with any provision of
         this Agreement (including the reasonable compensation and the expenses
         and disbursements of its agents and counsel), except any such expense,
         disbursement or advance as may be attributable to its undertaking its
         normal administrative functions, or its negligence, willful misconduct
         or bad faith or as may be incurred due to the Trustee's breach of its
         representations and warranties set forth in Section 7.15; and

                  (3) to indemnify, or cause to be indemnified, the Trustee for,
         and to hold it harmless against, any loss, liability, expense or Tax
         (other than for or with respect to any Unindemnified Tax) incurred
         without negligence, willful misconduct or bad faith, on its part,
         arising out of or in connection with the acceptance or administration
         of this Trust, including the costs and expenses of defending itself
         against any claim or liability in connection with the exercise or
         performance of any of its powers or duties hereunder, except for any
         such loss, liability or expense incurred by reason of the Trustee's
         breach of its covenants hereunder or under any Financing Document to
         which it is a party or its representations and warranties set forth in
         Section 7.15 or in any other Financing Document, the authorization or
         giving or withholding of any future amendments, supplements, waivers or
         consents with respect hereto or any of the Financing Documents, which
         amendments, supplements, waivers or consents are not required pursuant
         to the terms of the Financing Documents and not requested by the
         Company, any loss of tax benefits, any Unindemnified Tax, or increase
         in tax liability under any tax law whether or not the Company is
         required to indemnify thereof or pursuant to this Agreement or any
         costs associated with overhead or normal administration hereunder or
         any voluntary resignation pursuant to Section 7.09.

                  With respect to paragraph (3) above, the Trustee shall notify
the Company promptly of any claim for which it may seek indemnity and the
Company shall make payment on any such claim within 30 days of written demand
thereof (delivered together with supporting documentation). The Company shall
defend the claim and the Trustee shall cooperate in the defense. The Trustee may
have separate counsel with the consent of the Company and the Company will pay
the reasonable fees and expenses of such counsel. The Company need not pay for
any settlement made, in settlement or otherwise, without its consent.

                  With respect to any Tax other than an Unindemnified Tax, the
Trustee shall be entitled to reimbursement from, and shall have a lien prior to
the Certificates upon, the Trust Property for any such Tax incurred without
negligence, bad faith or willful misconduct, on its part, arising out of or in
connection with the acceptance or administration of such Trust (other than any
Tax attributable to the Trustee's compensation for serving as such), including
any costs and expenses incurred in contesting the imposition of any such Tax. If
the Trustee reimburses itself from the Trust Property of such Trust for any such
Tax, it will mail a brief report within 30 days setting forth the circumstances
thereof to all Certificateholders as their names and addresses appear in the
Register.
<PAGE>   47
                                      -42-


                  Section 7.08. Corporate Trustee Required; Eligibility. There
shall at all times be a Trustee hereunder which shall be eligible to act as a
trustee under Section 310(a) of the Trust Indenture Act and shall have a
combined capital and surplus of at least $75,000,000 (or a combined capital and
surplus in excess of $5,000,000 and the obligations of which, whether now in
existence or hereafter incurred, are fully and unconditionally guaranteed by a
corporation organized and doing business under the laws of the United States,
any state or territory thereof or of the District of Columbia and having a
combined capital and surplus of at least $75,000,000). If such corporation
publishes reports of conditions at least annually, pursuant to law or to the
requirements of federal, state, territorial or District of Columbia supervising
or examining authority, then for the purposes of this Section 7.08, the combined
capital and surplus of such corporation shall be deemed to be its combined
capital and surplus as set forth in its most recent report of conditions so
published.

                  In case at any time the Trustee shall cease to be eligible in
accordance with the provisions of this Section 7.08 to act as Trustee, the
Trustee shall resign immediately as Trustee in the manner and with the effect
specified in Section 7.09.

                  Section 7.09 Resignation and Removal; Appointment of
Successor. (a) No resignation or removal of the Trustee and no appointment of a
successor Trustee pursuant to this Article shall become effective until the
acceptance of appointment by the successor Trustee under Section 7.10.

                  (b) The Trustee may resign at any time as trustee by giving
prior written notice thereof to the Company, the Authorized Agents, the Owner
Trustees and the Loan Trustees. If an instrument of acceptance by a successor
Trustee shall not have been delivered to the Company, the Authorized Agents, the
Owner Trustees, the Loan Trustees and the Trustee within 30 days after the
giving of such notice of resignation, the resigning Trustee may petition any
court of competent jurisdiction for the appointment of a successor Trustee.

                  (c) The Trustee may be removed at any time by Direction of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not less than a majority in interest in the Trust
delivered to the Trustee and to the Company, the Owner Trustees and the Loan
Trustees.

                  (d) If at any time:

                  (1) the Trustee shall fail to comply with Section 310 of the
         Trust Indenture Act, if applicable, after written request therefor by
         the Company or by any Certificateholder who has been a bona fide
         Certificateholder for at least six months; or

                  (2) the Trustee shall cease to be eligible under Section 7.08
         and shall fail to resign after written request therefor by the Company
         or by any such Certificateholder; or

                  (3) the Trustee shall become incapable of acting or shall be
         adjudged a bankrupt or insolvent or a receiver of the Trustee or of its
         property shall be appointed or any public officer shall take charge or
         control of the Trustee or of its property or affairs for the purpose of
         rehabilitation, conservation or liquidation;
<PAGE>   48
                                      -43-


then, in any case, (i) the Company may remove the Trustee or (ii) any
Certificateholder who has been a bona fide Certificateholder for at least six
months may, on behalf of itself and all others similarly situated, petition any
court of competent jurisdiction for the removal of the Trustee and the
appointment of a successor Trustee.

                  (e) If a Responsible Officer of the Trustee shall obtain
actual knowledge of an Avoidable Tax which has been or is likely to be asserted,
the Trustee shall promptly notify the Company and shall, within 30 days of such
notification, resign hereunder unless within such 30-day period the Trustee
shall have received notice that the Company has agreed to pay such tax. The
Company shall promptly appoint a successor Trustee in a jurisdiction where there
are no Avoidable Taxes.

                  (f) If the Trustee shall resign, be removed or become
incapable of acting or if a vacancy shall occur in the office of the Trustee for
any cause, the Company shall promptly appoint a successor Trustee. If, within
one year after such resignation, removal or incapability, or other occurrence of
such vacancy, a successor Trustee shall be appointed by Direction of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not less than a majority in interest in the Trust
delivered to the Company, the Owner Trustees, the Loan Trustees and the retiring
Trustee, and the Company approves such appointment, which approval shall not be
unreasonably withheld, then the successor Trustee so appointed shall, forthwith
upon its acceptance of such appointment, become the successor Trustee and
supersede the successor Trustee appointed as provided above. If no successor
Trustee shall have been so appointed as provided above and accepted appointment
in the manner hereinafter provided, any Certificateholder who has been a bona
fide Certificateholder for at least six months may, on behalf of himself and all
others similarly situated, petition any court of competent jurisdiction for the
appointment of a successor Trustee.

                  (g) The successor Trustee shall give notice of the resignation
and removal of the Trustee and appointment of the successor Trustee by mailing
written notice of such event by first-class mail, postage prepaid, to the
Certificateholders as their names and addresses appear in the Register. Each
notice shall include the name of such successor Trustee and the address of its
Corporate Trust Office.

                  Section 7.10. Acceptance of Appointment by Successor. Every
successor Trustee appointed hereunder shall execute and deliver to the Company,
the Authorized Agents, the Owner Trustees and the Loan Trustees and to the
retiring Trustee an instrument accepting such appointment, and thereupon the
resignation or removal of the retiring Trustee shall become effective and such
successor Trustee, without any further act, deed or conveyance, shall become
vested with all the rights, powers, trusts and duties of the retiring Trustee;
but, on request of the Company or the successor Trustee, such retiring Trustee
shall execute and deliver an instrument transferring to such successor Trustee
all such rights, powers and trusts of the retiring Trustee and shall duly
assign, transfer and deliver to such successor Trustee all Trust Property held
by such retiring Trustee hereunder, subject nevertheless to its lien, if any,
provided for in Section 7.07. Upon request of any such successor Trustee, the
Company, the retiring Trustee and such successor Trustee shall execute and
deliver any and all instruments containing such provisions as shall be necessary
or desirable to transfer and confirm to, and for more fully and certainly
vesting in, such successor Trustee all such rights, powers and trusts.
<PAGE>   49
                                      -44-


                  No institution shall accept its appointment as a Trustee
hereunder unless at the time of such acceptance such institution shall be
qualified and eligible under this Article VII.

                  Section 7.11. Merger, Conversion, Consolidation or Succession
to Business. Any corporation into which the Trustee may be merged or converted
or with which it may be consolidated, or any corporation resulting from any
merger, conversion or consolidation to which the Trustee shall be a party, or
any corporation succeeding to all or substantially all of the corporate trust
business of the Trustee, shall be the successor of the Trustee hereunder,
provided such corporation shall be otherwise qualified and eligible under this
Article VII, without the execution or filing of any paper or any further act on
the part of any of the parties hereto. In case any Certificates shall have been
executed or authenticated, but not delivered, by the Trustee then in office, any
successor by merger, conversion or consolidation to such authenticating Trustee
may adopt such execution or authentication and deliver the Certificates so
executed or authenticated with the same effect as if such successor Trustee had
itself executed or authenticated such Certificates.

                  Section 7.12. Maintenance of Agencies. (a) There shall at all
times be maintained an office or agency in the location set forth in Section
12.03 where Certificates may be presented or surrendered for registration of
transfer or for exchange, and for payment thereof and where notices and demands
to or upon the Trustee in respect of such certificates or this Agreement may be
served; provided, however, that, if it shall be necessary that the Trustee
maintain an office or agency in another location (e.g., the Certificates shall
be represented by Definitive Certificates and shall be listed on a national
securities exchange), the Trustee will make all reasonable efforts to establish
such an office or agency. Written notice of the location of each such other
office or agency and of any change of location thereof shall be given by the
Trustee to the Company, the Owner Trustees, the Loan Trustees (in the case of
any Owner Trustee or Loan Trustee, at its address specified in the Financing
Documents or such other address as may be notified to the Trustee) and the
Certificateholders. In the event that no such office or agency shall be
maintained or no such notice of location or of change of location shall be
given, presentations and demands may be made and notices may be served at the
Corporate Trust Office of the Trustee.

                  (b) There shall at all times be a Registrar and a Paying Agent
hereunder with respect to the Certificates. Each such Authorized Agent shall be
a bank or trust company, shall be a corporation organized and doing business
under the laws of the United States or any state, with a combined capital and
surplus of at least $75,000,000, or, if the Trustee shall be acting as the
Registrar or Paying Agent hereunder, a corporation having a combined capital and
surplus in excess of $5,000,000, the obligations of which are guaranteed by a
corporation organized and doing business under the laws of the United States or
any state, with a combined capital and surplus of at least $75,000,000, and
shall be authorized under such laws to exercise corporate trust powers, subject
to supervision by Federal or state authorities. The Trustee shall initially be
the Paying Agent and, as provided in Section 3.04, Registrar hereunder with
respect to the Certificates. Each Registrar shall furnish to the Trustee, at
stated intervals of not more than six months, and at such other times as the
Trustee may request in writing, a copy of the Register maintained by such
Registrar.
<PAGE>   50
                                      -45-


                  (c) Any corporation into which any Authorized Agent may be
merged or converted or with which it may be consolidated, or any corporation
resulting from any merger, consolidation or conversion to which any Authorized
Agent shall be a party, or any corporation succeeding to the corporate trust
business of any Authorized Agent, shall be the successor of such Authorized
Agent hereunder, if such successor corporation is otherwise eligible under this
Section, without the execution or filing of any paper or any further act on the
part of the parties hereto or such Authorized Agent or such successor
corporation.

                  (d) Any Authorized Agent may at any time resign by giving
written notice of resignation to the Trustee, the Company, the Owner Trustees
and the Loan Trustees. The Company may, and at the request of the Trustee shall,
at any time terminate the agency of any Authorized Agent by giving written
notice of termination to such Authorized Agent and to the Trustee. Upon the
resignation or termination of an Authorized Agent or in case at any time any
such Authorized Agent shall cease to be eligible under this Section (when, in
either case, no other Authorized Agent performing the functions of such
Authorized Agent shall have been appointed), the Company shall promptly appoint
one or more qualified successor Authorized Agents, reasonably satisfactory to
the Trustee, to perform the functions of the Authorized Agent which has resigned
or whose agency has been terminated or who shall have ceased to be eligible
under this Section. The Company shall give written notice of any such
appointment made by it to the Trustee, the Owner Trustees and the Loan Trustees;
and in each case the Trustee shall mail notice of such appointment to all
Certificateholders as their names and addresses appear on the Register.

                  (e) The Company agrees to pay, or cause to be paid, from time
to time to each Authorized Agent reasonable compensation for its services and to
reimburse it for its reasonable expenses as set forth in the letter agreement
referred to in Section 7.07 hereof.

                  Section 7.13. Money for Certificate Payments to Be Held in
Trust. All moneys deposited with any Paying Agent for the purpose of any payment
on Certificates shall be deposited and held in trust for the benefit of the
Certificateholders entitled to such payment, subject to the provisions of this
Section. Moneys so deposited and held in trust shall constitute a separate trust
fund for the benefit of the Certificateholders with respect to which such money
was deposited.

                  The Trustee may at any time, for the purpose of obtaining the
satisfaction and discharge of this Agreement or for any other purpose, direct
any Paying Agent to pay to the Trustee all sums held in trust by such Paying
Agent, such sums to be held by the Trustee upon the same trusts as those upon
which such sums were held by such Paying Agent; and, upon such payment by any
Paying Agent to the Trustee, such Paying Agent shall be released from all
further liability with respect to such money.

                  Section 7.14. Registration of Equipment Notes in Name of
Subordination Agent. The Trustee agrees that all Equipment Notes to be purchased
by the Trust shall be issued in the name of the Subordination Agent or its
nominee and held by the Subordination Agent in trust for the benefit of the
Certificateholders, or, if not so held, the Subordination Agent or its nominee
shall be reflected as the owner of such Equipment Notes in the register of the
issuer of such Equipment Notes.
<PAGE>   51
                                      -46-


                  Section 7.15. Representations and Warranties of Trustee. The
Trustee hereby represents and warrants that:

                  (a) the Trustee is a Delaware banking corporation organized
and validly existing in good standing under the laws of the State of Delaware;

                  (b) the Trustee has full power, authority and legal right to
execute, deliver, and perform this Agreement, the Intercreditor Agreement, the
Registration Rights Agreement, the Escrow Agreement, the Note Purchase Agreement
and the Financing Documents to which it is a party and has taken all necessary
action to authorize the execution, delivery, and performance by it of this
Agreement, the Intercreditor Agreement, the Registration Rights Agreement, the
Escrow Agreement, the Note Purchase Agreement and the Financing Documents to
which it is a party;

                  (c) the execution, delivery and performance by the Trustee of
this Agreement, the Intercreditor Agreement, the Registration Rights Agreement,
the Escrow Agreement, the Note Purchase Agreement and the Financing Documents to
which it is a party (i) will not violate any provision of United States federal
law or the law of the state of the United States where it is located governing
the banking and trust powers of the Trustee or any order, writ, judgment, or
decree of any court, arbitrator or governmental authority applicable to the
Trustee or any of its assets, (ii) will not violate any provision of the
articles of association or by-laws of the Trustee, or (iii) will not violate any
provision of, or constitute, with or without notice or lapse of time, a default
under, or result in the creation or imposition of any lien on any properties
included in the Trust Property pursuant to the provisions of any mortgage,
indenture, contract, agreement or other undertaking to which it is a party,
which violation, default or lien could reasonably be expected to have an adverse
effect on the Trustee's performance or ability to perform its duties hereunder
or thereunder or on the transactions contemplated herein or therein;

                  (d) the execution, delivery and performance by the Trustee of
this Agreement, the Intercreditor Agreement, the Registration Rights Agreement,
the Escrow Agreement, the Note Purchase Agreement, and the Financing Documents
to which it is a party will not require the authorization, consent, or approval
of, the giving of notice to, the filing or registration with, or the taking of
any other action in respect of, any governmental authority or agency of the
United States or the state of the United States where it is located regulating
the banking and corporate trust activities of the Trustee; and

                  (e) this Agreement, the Intercreditor Agreement, the
Registration Rights Agreement, the Escrow Agreement, the Note Purchase
Agreement, and the Financing Documents to which it is a party have been duly
executed and delivered by the Trustee and constitute the legal, valid, and
binding agreements of the Trustee, enforceable against it in accordance with
their respective terms, provided that enforceability may be limited by (i)
applicable bankruptcy, insolvency, reorganization, moratorium or similar laws
affecting the rights of creditors generally and (ii) general principles of
equity, regardless of whether applied in a proceeding in equity or at law.

                  Section 7.16. Withholding Taxes, Information Reporting. The
Trustee, as trustee of the grantor trust created by this Agreement, shall
exclude and withhold from each
<PAGE>   52
                                      -47-


distribution of principal, premium, if any, and interest and other amounts due
under this Agreement or under the Certificates any and all withholding taxes
applicable thereto as required by law. In addition, the Trustee shall remit such
amounts as would be required by Section 1446 of the Internal Revenue Code of
1986, as amended, if the Trust were characterized as a partnership engaged in a
U.S. trade or business for U.S. federal income tax purposes and shall withhold
such amounts from amounts distributable to or for the benefit of
Certificateholders or Investors that are not United States persons within the
meaning of Section 7701(a)(30) of the Internal Revenue Code of 1986, as amended.
In this regard, the Trustee shall cause the appropriate withholding agent to
withhold with respect to such distributions in the manner contemplated by
Section 10.04 of Revenue Procedure 89-31 and Treasury Regulation 1.1445-8(b)(3)
by filing a notice with the National Association of Securities Dealers, Inc.
substantially in the form of Exhibit E hereto on or before the date 10 days
prior to the Record Date. The Trustee shall mail such notice to the National
Association of Securities Dealers no later than the date than 15 days prior to
the Record Date. Investors that are not United States Persons agree to furnish a
United States taxpayer identification number ("TIN") to the Trustee and the
Trustee shall provide such TINs to the appropriate withholding agent. The
Trustee agrees to act as such withholding agent (except to the extent
contemplated above with respect to withholding amounts as if the Trust were
characterized as a partnership engaged in a U.S. trade or business for U.S.
federal income tax purposes) and, in connection therewith, whenever any present
or future taxes or similar charges are required to be withheld with respect to
any amounts payable in respect of the Certificates, to withhold such amounts and
timely pay the same to the appropriate authority in the name of and on behalf of
the Certificateholders, that it will file any necessary withholding tax returns
or statements when due, and that, as promptly as possible after the payment
thereof, it will deliver to each such Certificateholder appropriate
documentation showing the payment thereof, together with such additional
documentary evidence as such Certificateholders may reasonably request from time
to time. The Trustee agrees to file any other information reports as it may be
required to file under United States law. Each Certificateholder or Investor
that is not a United States person within the meaning of Section 7701(a)(30) of
the Internal Revenue Code, as amended, by its acceptance of a Certificate or a
beneficial interest therein, agrees to indemnify and hold harmless the Trust and
the Trustee from and against any improper failure to withhold taxes from amounts
payable to it or for its benefit, other than an improper failure attributable to
the gross negligence or willful misconduct of the Trustee.

                  Section 7.17. Trustee's Liens. The Trustee in its individual
capacity agrees that it will at its own cost and expense promptly take any
action as may be necessary to duly discharge and satisfy in full any mortgage,
pledge, lien, charge, encumbrance, security interest or claim ("Trustee's
Liens") on or with respect to the Trust Property which is attributable to the
Trustee either (i) in its individual capacity and which is unrelated to the
transactions contemplated by this Agreement, the Intercreditor Agreement, the
Note Purchase Agreement or the Financing Documents, or (ii) as Trustee hereunder
or in its individual capacity and which arises out of acts or omissions on the
part of the Trustee which are not contemplated by this Agreement.

                  Section 7.18. Preferential Collection of Claims. The Trustee
shall comply with Section 311(a) of the Trust Indenture Act, excluding any
creditor relationship listed in
<PAGE>   53
                                      -48-


Section 311(b) of the Trust Indenture Act. If the Trustee shall resign or be
removed as Trustee, it shall be subject to Section 311(a) of the Trust Indenture
Act to the extent provided therein.

                                  ARTICLE VIII

                CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE

                  Section 8.01. The Company to Furnish Trustee with Names and
Addresses of Certificateholders. The Company will furnish to the Trustee within
15 days after each Record Date with respect to a Scheduled Payment, and at such
other times as the Trustee may request in writing within 30 days after receipt
by the Company of any such request, a list, in such form as the Trustee may
reasonably require, of all information in the possession or control of the
Company as to the names and addresses of the Certificateholders, in each case as
of a date not more than 15 days prior to the time such list is furnished;
provided, however, that so long as the Trustee is the sole Registrar, no such
list need be furnished; and provided further, however, that no such list need be
furnished for so long as a copy of the Register is being furnished to the
Trustee pursuant to Section 7.12.

                  Section 8.02. Preservation of Information; Communications to
Certificateholders. The Trustee shall preserve, in as current a form as is
reasonably practicable, the names and addresses of Certificateholders contained
in the most recent list furnished to the Trustee as provided in Section 7.12 or
Section 8.01, as the case may be, and the names and addresses of
Certificateholders received by the Trustee in its capacity as Registrar, if so
acting. The Trustee may destroy any list furnished to it as provided in Section
7.12 or Section 8.01, as the case may be, upon receipt of a new list so
furnished.

                  Section 8.03. Reports by Trustee. Within 60 days after May 15
of each year commencing with the first full year following the issuance of the
Certificates, the Trustee shall transmit to the Certificateholders, as provided
in Section 313(c) of the Trust Indenture Act, a brief report dated as of such
May 15, if required by Section 313(a) of the Trust Indenture Act.

                  Section 8.04. Reports by the Company. The Company shall:

                  (a) file with the Trustee, within 30 days after the Company is
         required to file the same with the SEC, copies of the annual reports
         and of the information, documents and other reports (or copies of such
         portions of any of the foregoing as the SEC may from time to time by
         rules and regulations prescribe) which the Company is required to file
         with the SEC pursuant to Section 13 or Section 15(d) of the Securities
         Exchange Act of 1934, as amended; or, if the Company is not required to
         file information, documents or reports pursuant to either of such
         sections, then to file with the Trustee and the SEC, in accordance with
         rules and regulations prescribed by the SEC, such of the supplementary
         and periodic information, documents and reports which may be required
         pursuant to Section 13 of the Securities Exchange Act of 1934, as
         amended, in respect of a security listed and registered on a national
         securities exchange as may be prescribed in such rules and regulations;
<PAGE>   54
                                      -49-


                  (b) during any period, prior to the consummation of the
         Exchange Offer and during which the Shelf Registration Statement is not
         in effect, in which the Company is not subject to Section 13(a), 13(c)
         or 15(d) under the Securities Exchange Act of 1934, make available to
         any Holder of the Certificates in connection with any sale thereof and
         any prospective purchaser of the Certificates from such Holder, in each
         case upon request, the information specified in, and meeting the
         requirements of, Rule 144A(d)(4) under the Securities Act but only for
         so long as any of the Certificates remain outstanding and are
         "restricted securities" within the meaning of Rule 144(a)(3) under the
         Securities Act and, in any event, only until the second anniversary of
         the Issuance Date;

                  (c) file with the Trustee and the SEC, in accordance with the
         rules and regulations prescribed by the SEC, such additional
         information, documents and reports with respect to compliance by the
         Company with the conditions and covenants provided for in this
         Agreement, as may be required by such rules and regulations, including,
         in the case of annual reports, if required by such rules and
         regulations, certificates or opinions of independent public
         accountants, conforming to the requirements of Section 1.02;

                  (d) transmit to all Certificateholders, in the manner and to
         the extent provided in Section 313(c) of the Trust Indenture Act such
         summaries of any information, documents and reports required to be
         filed by the Company pursuant to subsections (a) and (c) of this
         Section 8.04 as may be required by rules and regulations prescribed by
         the SEC; and

                  (e) furnish to the Trustee, not less often than annually, a
         brief certificate from the principal executive officer, principal
         financial officer, any Vice President (or more senior ranking officer)
         or the principal accounting officer as to his or her knowledge of the
         Company's compliance with all conditions and covenants under this
         Agreement (it being understood that for purposes of this paragraph (e),
         such compliance shall be determined without regard to any period of
         grace or requirement of notice provided under this Agreement).

                                   ARTICLE IX

                             SUPPLEMENTAL AGREEMENTS

                  Section 9.01. Supplemental Agreements Without Consent of
Certificateholders. Without the consent of the Certificateholders, the Company
may (but will not be required to), and the Trustee (subject to Section 9.03)
shall, at the Company's request, at any time and from time to time, enter into
one or more agreements supplemental hereto or, if applicable, to the
Intercreditor Agreement, the Escrow Agreement, the Note Purchase Agreement, the
Deposit Agreement, the Registration Rights Agreement or any Liquidity Facility
in form satisfactory to the Trustee, for any of the following purposes:

                  (1) to evidence the succession of another corporation to the
         Company and the assumption by any such successor of the covenants of
         the Company herein contained or of the Company's obligations under the
         Note Purchase Agreement, the Registration Rights Agreement or any
         Liquidity Facility; or
<PAGE>   55
                                      -50-


                  (2) to add to the covenants of the Company for the benefit of
         the Certificateholders, or to surrender any right or power conferred
         upon the Company in this Agreement, the Note Purchase Agreement, the
         Registration Rights Agreement or any Liquidity Facility; or

                  (3) to correct or supplement any provision in this Agreement,
         the Intercreditor Agreement, the Escrow Agreement, the Deposit
         Agreement, the Note Purchase Agreement, the Registration Rights
         Agreement or any Liquidity Facility which may be defective or
         inconsistent with any other provision herein or therein or to cure any
         ambiguity or correct any mistake or to modify any other provision with
         respect to matters or questions arising under this Agreement, the
         Escrow Agreement, the Deposit Agreement, the Note Purchase Agreement,
         the Intercreditor Agreement, the Registration Rights Agreement or any
         Liquidity Facility, provided that any such action shall not materially
         adversely affect the interests of the Certificateholders; or

                  (4) to comply with any requirement of the SEC, any applicable
         law, rules or regulations of any exchange or quotation system on which
         the Certificates are listed, any regulatory body or the Registration
         Rights Agreement to effectuate the Exchange Offer; or

                  (5) to modify, eliminate or add to the provisions of this
         Agreement to such extent as shall be necessary to continue the
         qualification of this Agreement (including any supplemental agreement)
         under the Trust Indenture Act or under any similar Federal statute
         hereafter enacted, and to add to this Agreement such other provisions
         as may be expressly permitted by the Trust Indenture Act, excluding,
         however, the provisions referred to in Section 316(a)(2) of the Trust
         Indenture Act as in effect at the date as of which this instrument was
         executed or any corresponding provision in any similar Federal statute
         hereafter enacted; or

                  (6) to evidence and provide for the acceptance of appointment
         under this Agreement by the Trustee of a successor Trustee and to add
         to or change any of the provisions of this Agreement as shall be
         necessary to provide for or facilitate the administration of the Trust,
         pursuant to the requirements of Section 7.10; or

                  (7) to provide the information required under Section 7.12 and
         Section 12.03 as to the Trustee; or

                  (8) to modify or eliminate provisions relating to the transfer
         or exchange of Exchange Certificates or the Initial Certificates upon
         consummation of the Exchange Offer (as defined in the Registration
         Rights Agreement) or effectiveness of the Shelf Registration Statement
         or the Exchange Offer Registration Statement;

provided, however, that no such supplemental agreement shall adversely affect
the status of any Trust as a grantor trust under Subpart E, Part I of Subchapter
J of Chapter 1 of Subtitle A of the Internal Revenue Code of 1986, as amended,
for U.S. federal income tax purposes.

                  Section 9.02. Supplemental Agreements with Consent of
Certificateholders. With the consent of the Certificateholders holding
Certificates (including consents obtained in
<PAGE>   56
                                      -51-


connection with a tender offer or exchange offer for the Certificates)
evidencing Fractional Undivided Interests aggregating not less than a majority
in interest in the Trust, by Direction of said Certificateholders delivered to
the Company and the Trustee, the Company may (with the consent of the Owner
Trustees, if any, which consent shall not be unreasonably withheld), and the
Trustee (subject to Section 9.03) shall, enter into an agreement or agreements
for the purpose of adding any provisions to or changing in any manner or
eliminating any of the provisions of this Agreement, the Intercreditor
Agreement, any Liquidity Facility, the Registration Rights Agreement, the Escrow
Agreement, the Deposit Agreement or the Note Purchase Agreement to the extent
applicable to such Certificateholders or of modifying in any manner the rights
and obligations of such Certificateholders under this Agreement, the
Intercreditor Agreement, any Liquidity Facility, the Registration Rights
Agreement, the Escrow Agreement, the Deposit Agreement or the Note Purchase
Agreement to the extent applicable to such Certificateholders or of modifying in
any manner the rights and obligations of such Certificateholders under this
Agreement, the Intercreditor Agreement, any Liquidity Facility, the Registration
Rights Agreement, the Escrow Agreement, the Deposit Agreement or the Note
Purchase Agreement; provided, however, that no such agreement shall, without the
consent of the Certificateholder of each Outstanding Certificate affected
thereby:

                  (1) reduce in any manner the amount of, or delay the timing
         of, any receipt by the Trustee (or, with respect to the Deposits, the
         Certificateholders) of payments on the Equipment Notes held in the
         Trust or on the Deposits or distributions that are required to be made
         herein on any Certificate, or change any date of payment on any
         Certificate, or change the place of payment where, or the coin or
         currency in which, any Certificate is payable, or impair the right to
         institute suit for the enforcement of any such payment or distribution
         on or after the Regular Distribution Date or Special Distribution Date
         applicable thereto; or

                  (2) permit the disposition of any Equipment Note included in
         the Trust Property except as permitted by this Agreement, or otherwise
         deprive such Certificateholder of the benefit of the ownership of the
         Equipment Notes in the Trust; or

                  (3) reduce the specified percentage of the aggregate
         Fractional Undivided Interests of the Trust which is required for any
         such supplemental agreement, or reduce such specified percentage
         required for any waiver of compliance with certain provisions of this
         Agreement or certain defaults hereunder and their consequences provided
         for in this Agreement; or

                  (4) waive, amend or modify Section 2.4, 3.2 or 3.3 of the
         Intercreditor Agreement in a manner adverse to the Certificateholders;
         or

                  (5) modify any of the provisions of this Section 9.02 or
         Section 6.05, except to increase any such percentage or to provide that
         certain other provisions of this Agreement cannot be modified or waived
         without the consent of the Certificateholder of each Certificate
         affected thereby; or
<PAGE>   57
                                      -52-


                  (6) adversely affect the status of any Trust as a grantor
         trust under Subpart E, Part I of Subchapter J of Chapter 1 of Subtitle
         A of the Internal Revenue Code of 1986, as amended, for U.S. federal
         income tax purposes.

                  It shall not be necessary for any Direction of
Certificateholders under this Section to approve the particular form of any
proposed supplemental agreement, but it shall be sufficient if such Direction
shall approve the substance thereof.

                  Section 9.03. Documents Affecting Immunity or Indemnity.
Except for the performance of its covenants herein, if in the opinion of the
Trustee any document required to be executed by it pursuant to the terms of
Section 9.01 or 9.02 affects adversely any interest, right, duty, immunity or
indemnity in favor of the Trustee under this Agreement, the Trustee may in its
discretion decline to execute such document.

                  Section 9.04. Execution of Supplemental Agreements. In
executing, or accepting the additional trusts created by, any agreement
permitted by this Article or the modifications thereby of the trusts created by
this Agreement, the Trustee shall be entitled to receive, and shall be fully
protected in relying upon, an Opinion of Counsel stating that the execution of
such supplemental agreement is authorized or permitted by this Agreement.

                  Section 9.05. Effect of Supplemental Agreements. Upon the
execution of any agreement supplemental to this Agreement under this Article,
this Agreement shall be modified in accordance therewith, and such supplemental
agreement shall form a part of this Agreement for all purposes; and every Holder
of a Certificate theretofore or thereafter authenticated and delivered hereunder
shall be bound thereby.

                  Section 9.06. Conformity with Trust Indenture Act. Every
supplemental agreement executed pursuant to this Article shall conform to the
requirements of the Trust Indenture Act as then in effect.

                  Section 9.07. Reference in Certificates to Supplemental
Agreements. Certificates authenticated and delivered after the execution of any
supplemental agreement pursuant to this Article may bear a notation in form
approved by the Trustee as to any matter provided for in such supplemental
agreement; and, in such case, suitable notation may be made upon Outstanding
Certificates after proper presentation and demand.

                                    ARTICLE X

                AMENDMENTS TO INDENTURES AND FINANCING DOCUMENTS

                  Section 10.01. Amendments and Supplements to Indentures and
Financing Documents. In the event that the Trustee, as holder (or beneficial
owner through the Subordination Agent) of any Equipment Note in trust for the
benefit of the Certificateholders or as Controlling Party under the
Intercreditor Agreement, receives (directly or indirectly through the
Subordination Agent) a request for a consent to any amendment, modification,
waiver or supplement under any Indenture, any other Financing Document, any
Equipment Note or any other related document, the Trustee shall forthwith send a
notice of such proposed amendment,
<PAGE>   58
                                      -53-


modification, waiver or supplement to each Certificateholder registered on the
Register as of the date of such notice. The Trustee shall request from the
Certificateholders a Direction as to (a) whether or not to take or refrain from
taking (or direct the Subordination Agent to take or refrain from taking) any
action which a holder of such Equipment Note has the option to direct, (b)
whether or not to give or execute (or direct the Subordination Agent to give or
execute) any waivers, consents, amendments, modifications or supplements as a
holder of such Equipment Note or a Controlling Party and (c) how to vote (or
direct the Subordination Agent to vote) any Equipment Note if a vote has been
called for with respect thereto. Provided such a request for Certificateholder
Direction shall have been made, in directing any action or casting any vote or
giving any consent as the holder of any Equipment Note (or in directing the
Subordination Agent in any of the foregoing), (i) other than as Controlling
Party, the Trustee shall vote for or give consent to any such action with
respect to such Equipment Note in the same proportion as that of (A) the
aggregate face amounts of all Certificates actually voted in favor of or for
giving consent to such action by such Direction of Certificateholders to (B) the
aggregate face amount of all Outstanding Certificates and (ii) as Controlling
Party, the Trustee shall vote as directed in such Certificateholder Direction by
the Certificateholders evidencing a Fractional Undivided Interest aggregating
not less than a majority in interest in the Trust. For purposes of the
immediately preceding sentence, a Certificate shall have been "actually voted"
if the Holder of such Certificate has delivered to the Trustee an instrument
evidencing such Holder's consent to such Direction prior to two Business Days
before the Trustee directs such action or casts such vote or gives such consent.
Notwithstanding the foregoing, but subject to Section 6.04 and the Intercreditor
Agreement, the Trustee may, in its own discretion and at its own direction,
consent and notify the relevant Loan Trustee of such consent (or direct the
Subordination Agent to consent and notify the Loan Trustee of such consent) to
any amendment, modification, waiver or supplement under the relevant Indenture,
any other Financing Document, any Equipment Note or any other related document,
if an Event of Default hereunder shall have occurred and be continuing, or if
such amendment, modification, waiver or supplement will not materially adversely
affect the interests of the Certificateholders.

                                   ARTICLE XI

                              TERMINATION OF TRUST

                  Section 11.01. Termination of the Trust. The respective
obligations and responsibilities of the Company and the Trustee with respect to
the Trust shall terminate upon the earlier of (A) the completion of the
assignment, transfer and discharge described in the first sentence of the
immediately following paragraph and (B) distribution to all Holders of
Certificates and the Trustee of all amounts required to be distributed to them
pursuant to this Agreement and the disposition of all property held as part of
the Trust Property; provided, however, that in no event shall the Trust continue
beyond one hundred ten (110) years following the date of the earliest execution
of this Trust Agreement.

                  Upon the earlier of (i) the first Business Day after November
30, 1999, or, if later, the fifth Business Day following the Delivery Period
Termination Date and (ii) the fifth Business Day following the date on which a
Triggering Event occurs (such date, the "Transfer Date"), or, if later the date
on which all of the conditions set forth in the immediately following sentence
<PAGE>   59
                                      -54-


have been satisfied, the Trustee is hereby directed (subject only to the
immediately following sentence) to, and the Company shall direct the institution
that will serve as the Related Trustee under the Related Pass Through Trust
Agreement to, execute and deliver the Assignment and Assumption Agreement,
pursuant to which the Trustee shall assign, transfer and deliver all of the
Trustee's right, title and interest to the Trust Property to the Related Trustee
under the Related Pass Through Trust Agreement. The Trustee and the Related
Trustee shall execute and deliver the Assignment and Assumption Agreement upon
the satisfaction of the following conditions:

                  (i) The Trustee, the Related Trustee and each of the Rating
         Agencies then rating the Certificates shall have received an Officer's
         Certificate and an Opinion of Counsel dated the date of the Assignment
         and Assumption Agreement and each satisfying the requirements of
         Section 1.02, which Opinion of Counsel shall be substantially to the
         effect set forth below and may be relied upon by the Beneficiaries (as
         defined in the Assignment and Assumption Agreement):

                  (a)      upon the execution and delivery thereof by the
                           parties thereto in accordance with the terms of this
                           Agreement and the Related Pass Through Trust
                           Agreement, the Assignment and Assumption Agreement
                           will constitute the valid and binding obligation of
                           each of the parties thereto enforceable against each
                           such party in accordance with its terms;

                  (b)      upon the execution and delivery of the Assignment and
                           Assumption Agreement in accordance with the terms of
                           this Agreement and the Related Pass Through Trust
                           Agreement, each of the Certificates then Outstanding
                           will be entitled to the benefits of the Related Pass
                           Through Trust Agreement;

                  (c)      the Related Trust is not required to be registered as
                           an investment company under the Investment Company
                           Act of 1940, as amended;

                  (d)      the Related Pass Through Trust Agreement constitutes
                           the valid and binding obligation of the Company
                           enforceable against the Company in accordance with
                           its terms; and

                  (e)      neither the execution and delivery of the Assignment
                           and Assumption Agreement in accordance with the terms
                           of this Agreement and the Related Pass Through Trust
                           Agreement, nor the consummation by the parties
                           thereto of the transactions contemplated to be
                           consummated thereunder on the date thereof, will
                           violate any law or governmental rule or regulation of
                           the State of New York or the United States of America
                           known to such counsel to be applicable to the
                           transactions contemplated by the Assignment and
                           Assumption Agreement.

                  (ii) The Trustee and the Company shall have received (x) a
         copy of the articles of incorporation and bylaws of the Related Trustee
         certified as of the Transfer Date by the Secretary or Assistant
         Secretary of such institution and (y) a copy of the filing (including
         all attachments thereto) made by the institution serving as the Related
         Trustee with the
<PAGE>   60
                                      -55-


         Office of the Superintendent, State of New York Banking Department for
         the qualification of the Related Trustee under Section 131(3) of the
         New York Banking Law.

Upon the execution of the Assignment and Assumption Agreement by the parties
thereto, the Trust shall be terminated, the Certificateholders shall receive
beneficial interests in the Related Trust in exchange for their interests in the
Trust equal to their respective beneficial interests in the Trust, and the
Outstanding Certificates representing Fractional Undivided Interests in the
Trust shall be deemed for all purposes of this Agreement and the Related Pass
Through Trust Agreement, without further signature or action of any party or
Certificateholder, to be certificates representing the same fractional undivided
interests in the Related Trust and its trust property. By acceptance of its
Certificate, each Certificateholder consents to such assignment, transfer and
delivery of the Trust Property to the trustee of the Related Trust upon the
execution and delivery of the Assignment and Assumption Agreement.

                  In connection with the occurrence of the event set forth in
clause (B) above, notice of such termination, specifying the Distribution Date
upon which the Certificateholders may surrender their Certificates to the
Trustee for payment of the final distribution and cancellation, shall be mailed
promptly by the Trustee to Certificateholders not earlier than the 60th day and
not later than the 20th day next preceding such final Distribution Date
specifying (A) the Distribution Date upon which the proposed final payment of
the Certificates will be made upon presentation and surrender of Certificates at
the office or agency of the Trustee therein specified, (B) the amount of any
such proposed final payment, and (C) that the Record Date otherwise applicable
to such Distribution Date is not applicable, payments being made only upon
presentation and surrender of the Certificates at the office or agency of the
Trustee therein specified. The Trustee shall give such notice to the Registrar
at the time such notice is given to Certificateholders. Upon presentation and
surrender of the Certificates in accordance with such notice, the Trustee shall
cause to be distributed to Certificateholders such final payments.

                  In the event that all of the Certificateholders shall not
surrender their Certificates for cancellation within six months after the date
specified in the above-mentioned written notice, the Trustee shall give a second
written notice to the remaining Certificateholders to surrender their
Certificates for cancellation and receive the final distribution with respect
thereto. No additional interest shall accrue on the Certificates after the
Distribution Date specified in the first written notice. In the event that any
money held by the Trustee for the payment of distributions on the Certificates
shall remain unclaimed for two years (or such lesser time as the Trustee shall
be satisfied, after sixty days' notice from the Company, is one month prior to
the escheat period provided under applicable law) after the final distribution
date with respect thereto, the Trustee shall pay to each Loan Trustee the
appropriate amount of money relating to such Loan Trustee and shall give written
notice thereof to the related Owner Trustees, the Owner Participants and the
Company.

                                   ARTICLE XII

                            MISCELLANEOUS PROVISIONS

                  Section 12.01. Limitation on Rights of Certificateholders. The
death or incapacity of any Certificateholder shall not operate to terminate this
Agreement or the Trust, nor entitle
<PAGE>   61
                                      -56-


such Certificateholder's legal representatives or heirs to claim an accounting
or to take any action or commence any proceeding in any court for a partition or
winding up of the Trust, nor otherwise affect the rights, obligations, and
liabilities of the parties hereto or any of them.

                  Section 12.02. Certificates Nonassessable and Fully Paid.
Except as set forth in the last sentence of this Section 12.02,
Certificateholders shall not be personally liable for obligations of the Trust,
the Fractional Undivided Interests represented by the Certificates shall be
nonassessable for any losses or expenses of the Trust or for any reason
whatsoever, and Certificates, upon authentication thereof by the Trustee
pursuant to Section 3.03, are and shall be deemed fully paid. No
Certificateholder shall have any right (except as expressly provided herein) to
vote or in any manner otherwise control the operation and management of the
Trust Property, the Trust, or the obligations of the parties hereto, nor shall
anything set forth herein, or contained in the terms of the Certificates, be
construed so as to constitute the Certificateholders from time to time as
partners or members of an association. Neither the existence of the Trust nor
any provision herein is intended to or shall limit the liability the
Certificateholders would otherwise incur if the Certificateholders owned Trust
Property as co-owners, or incurred any obligations of the Trust, directly rather
than through the Trust.

                  Section 12.03. Notices. (a) Unless otherwise specifically
provided herein, all notices required under the terms and provisions of this
Agreement shall be in English and in writing, and any such notice may be given
by United States mail, courier service or telecopy, and any such notice shall be
effective when received or, if made, given, furnished or filed by facsimile or
telecommunication transmission, when received unless received outside of
business hours, in which case on the next open of business on a Business Day,

                  if to the Company, to:

                           America West Airlines, Inc.
                           4000 East Sky Harbor Boulevard
                           Phoenix, Arizona  85043

                           Attention:  Vice President-
                                       Treasurer
                           Facsimile:  (602) 693-5886

                  if to the Trustee, to:

                           Wilmington Trust Company
                           Rodney Square North
                           1100 North Market Street
                           Wilmington, Delaware  19890-0001

                           Attention:  Corporate Trust Department
                           Facsimile:  (302) 651-8882
                           Telephone:   (302) 651-8584
<PAGE>   62
                                      -57-


                  (b) The Company or the Trustee, by notice to the other, may
designate additional or different addresses for subsequent notices or
communications.

                  (c) Any notice or communication to Certificateholders shall be
mailed by first-class mail to the addresses for Certificateholders shown on the
Register kept by the Registrar. Failure so to mail a notice or communication or
any defect in such notice or communication shall not affect its sufficiency with
respect to other Certificateholders.

                  (d) If a notice or communication is mailed in the manner
provided above within the time prescribed, it is conclusively presumed to have
been duly given, whether or not the addressee receives it.

                  (e) If the Company mails a notice or communication to the
Certificateholders, it shall mail a copy to the Trustee and to the Paying Agent
at the same time.

                  (f) Notwithstanding the foregoing, all communications or
notices to the Trustee shall be deemed to be given only when received by a
Responsible Officer of the Trustee.

                  (g) The Trustee shall promptly furnish the Company with a copy
of any demand, notice or written communication received by the Trustee hereunder
from any Certificateholder, Owner Trustee or Loan Trustee.

                  Section 12.04. Governing Law. THIS AGREEMENT HAS BEEN
DELIVERED IN THE STATE OF DELAWARE AND THIS AGREEMENT AND THE CERTIFICATES SHALL
BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF
DELAWARE AND THE OBLIGATIONS, RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER SHALL
BE DETERMINED IN ACCORDANCE WITH SUCH LAWS.

                  Section 12.05. Severability of Provisions. If any one or more
of the covenants, agreements, provisions or terms of this Agreement shall be for
any reason whatsoever held invalid, then such covenants, agreements, provisions,
or terms shall be deemed severable from the remaining covenants, agreements,
provisions or terms of this Agreement and shall in no way affect the validity or
enforceability of the other provisions of this Agreement or the Trust, or of the
Certificates or the rights of the Certificateholders thereof.

                  Section 12.06. Trust Indenture Act Controls. Upon the
occurrence of any Registration Event, this Agreement shall become subject to the
provisions of the Trust Indenture Act and shall, to the extent applicable, be
governed by such provisions. From and after any Registration Event, if any
provision of this Agreement limits, qualifies or conflicts with another
provision which is required to be included in this Agreement by the Trust
Indenture Act, the required provision shall control.

                  Section 12.07. Effect of Headings and Table of Contents. The
Article and Section headings herein and the Table of Contents are for
convenience only and shall not affect the construction hereof.
<PAGE>   63
                                      -58-


                  Section 12.08. Successors and Assigns. All covenants,
agreements, representations and warranties in this Agreement by the Trustee and
the Company shall bind and, to the extent permitted hereby, shall inure to the
benefit of and be enforceable by their respective successors and assigns,
whether so expressed or not.

                  Section 12.09. Benefits of Agreement. Nothing in this
Agreement or in the Certificates, express or implied, shall give to any Person,
other than the parties hereto and their successors hereunder, and the
Certificateholders, any benefit or any legal or equitable right, remedy or claim
under this Agreement.

                  Section 12.10. Legal Holidays. In any case where any Regular
Distribution Date or Special Distribution Date relating to any Certificate shall
not be a Business Day, then (notwithstanding any other provision of this
Agreement) payment need not be made on such date, but may be made on the next
succeeding Business Day with the same force and effect as if made on such
Regular Distribution Date or Special Distribution Date, and no interest shall
accrue during the intervening period.

                  Section 12.11. Counterparts. For the purpose of facilitating
the execution of this Agreement and for other purposes, this Agreement may be
executed simultaneously in any number of counterparts, each of which
counterparts shall be deemed to be an original, and all of which counterparts
shall constitute but one and the same instrument.

                  Section 12.12. Intention of Parties. The parties hereto intend
that the Trust be classified for U.S. federal income tax purposes as a grantor
trust under Subpart E, Part I of Subchapter J of the Internal Revenue Code of
1986, as amended, and not as a trust or association taxable as a corporation or
as a partnership. Each Certificateholder and Investor, by its acceptance of its
Certificate or a beneficial interest therein, agrees to treat the Trust as a
grantor trust for all U.S. federal, state and local income tax purposes. The
powers granted and obligations undertaken pursuant to this Agreement shall be so
construed so as to further such intent.
<PAGE>   64
                                      -59-



                  IN WITNESS WHEREOF, the parties have caused this Agreement to
be duly executed by their respective officers thereunto duly authorized as of
the day and year first written above.


                                       AMERICA WEST AIRLINES, INC.


                                       By:   /s/ W. Douglas Parker
                                             _______________________
                                             Name: W. Douglas Parker
                                             Title: Sr. Vice President & CFO


                                       WILMINGTON TRUST COMPANY,
                                             as Trustee


                                       By:   /s/ Jill K. Morrison
                                             _______________________
                                             Name: Jill K. Morrison
                                             Title: Administrative Account
                                                    Manager


<PAGE>   65
                                                                       EXHIBIT A

                               FORM OF CERTIFICATE

REGISTERED

No._________

         [THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE U.S. SECURITIES ACT
         OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND ACCORDINGLY, MAY NOT BE
         OFFERED OR SOLD WITHIN THE UNITED STATES OR TO, OR FOR THE ACCOUNT OR
         BENEFIT OF, ANY PERSONS EXCEPT AS SET FORTH IN THE FOLLOWING SENTENCE.
         BY ITS ACQUISITION HEREOF, THE HOLDER (1) REPRESENTS THAT (A) IT IS A
         "QUALIFIED INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A UNDER THE
         SECURITIES ACT), (B) IT IS AN INSTITUTIONAL "ACCREDITED INVESTOR" (AS
         DEFINED IN RULE 501(a)(1), (2), (3) OR (7) OF REGULATION D UNDER THE
         SECURITIES ACT) (AN "INSTITUTIONAL ACCREDITED INVESTOR") OR (C) IT IS
         NOT A U.S. PERSON AND IS ACQUIRING THIS CERTIFICATE IN AN OFFSHORE
         TRANSACTION IN COMPLIANCE WITH REGULATION S UNDER THE SECURITIES ACT;
         (2) AGREES THAT IT WILL NOT WITHIN TWO YEARS AFTER THE LATER OF THE
         ORIGINAL ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS
         CERTIFICATE WAS HELD BY AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY
         AFFILIATE OF ANY OF SUCH PERSONS RESELL OR OTHERWISE TRANSFER THIS
         CERTIFICATE EXCEPT (A) AMERICA WEST AIRLINES, INC., (B) TO A QUALIFIED
         INSTITUTIONAL BUYER IN COMPLIANCE WITH RULE 144A UNDER THE SECURITIES
         ACT, (C) OUTSIDE THE UNITED STATES IN AN OFFSHORE TRANSACTION IN
         COMPLIANCE WITH RULE 904 UNDER THE SECURITIES ACT, (D) PURSUANT TO THE
         EXEMPTION FROM REGISTRATION PROVIDED BY RULE 144 UNDER THE SECURITIES
         ACT (IF AVAILABLE) OR (E) PURSUANT TO AN EFFECTIVE REGISTRATION
         STATEMENT UNDER THE SECURITIES ACT; AND (3) AGREES THAT IF IT SHOULD
         RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE IT WILL DELIVER TO EACH
         PERSON TO WHOM THIS CERTIFICATE IS TRANSFERRED A NOTICE SUBSTANTIALLY
         TO THE EFFECT OF THIS LEGEND. IN CONNECTION WITH ANY TRANSFER OF THIS
         CERTIFICATE WITHIN TWO YEARS AFTER THE LATER OF THE ORIGINAL ISSUANCE
         OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS CERTIFICATE WAS HELD
         BY AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY AFFILIATE OF ANY OF
         SUCH PERSONS, THE HOLDER MUST CHECK THE APPROPRIATE BOX SET FORTH ON
         THE REVERSE HEREOF RELATING TO THE MANNER OF SUCH TRANSFER AND SUBMIT
         THIS CERTIFICATE TO THE TRUSTEE. AS USED HEREIN, THE TERMS "OFFSHORE
         TRANSACTION", "UNITED STATES" AND "U.S. PERSON" HAVE THE MEANINGS GIVEN
         TO THEM BY REGULATION S UNDER THE SECURITIES ACT. THE PASS THROUGH
         TRUST AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO REFUSE TO
         REGISTER ANY
<PAGE>   66
                                      A-2


         TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE FOREGOING
         RESTRICTIONS.]*

         BY ITS ACQUISITION HEREOF, THE HOLDER REPRESENTS THAT (A) NO PLAN
         ASSETS HAVE BEEN USED TO PURCHASE THIS CERTIFICATE OR AN INTEREST
         HEREIN OR (B) THE PURCHASE AND HOLDING OF THIS CERTIFICATE OR AN
         INTEREST HEREIN IS EXEMPT FROM THE PROHIBITED TRANSACTION RESTRICTIONS
         OF ERISA AND THE CODE PURSUANT TO ONE OR MORE PROHIBITED TRANSACTION
         STATUTORY OR ADMINISTRATIVE EXEMPTIONS. THE PASS THROUGH TRUST
         AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO REFUSE TO
         REGISTER ANY TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE FOREGOING
         RESTRICTIONS.

         [UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE
         OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE
         TRUSTEE OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT,
         AND ANY CERTIFICATE ISSUED IN EXCHANGE FOR THIS CERTIFICATE IS
         REGISTERED IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS
         REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT
         HEREON IS MADE TO CEDE & CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY
         AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE
         HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH
         AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

         TRANSFERS OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO TRANSFERS IN
         WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A SUCCESSOR THEREOF OR
         SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL
         CERTIFICATE SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE
         RESTRICTIONS SET FORTH IN SECTIONS 3.05 AND 3.06 OF THE PASS THROUGH
         TRUST AGREEMENT REFERRED TO HEREIN.]**

- ----------

         *        Not to be included on the face of the Regulation S Global
                  Certificate.

         **       To be included on the face of each Global Certificate.
<PAGE>   67
                                      A-3


                             [GLOBAL CERTIFICATE]*

           AMERICA WEST AIRLINES PASS THROUGH TRUST, SERIES 1998-1B-O

                7.12% America West Airlines [Initial] [Exchange]
                            Pass Through Certificate,
                                Series 1998-1B-O

                   Final Legal Distribution Date: July 2, 2018

evidencing a fractional undivided interest in a trust, the property of which
includes certain equipment notes each secured by an Aircraft leased to or owned
by America West Airlines, Inc.

                  $__________ Fractional Undivided Interest representing
                  .0.0024298974% of the Trust per $1,000 face amount

                  THIS CERTIFIES THAT _______________, for value received, is
the registered owner of a $________ (__________dollars) Fractional Undivided
Interest in the America West Airlines Pass Through Trust, Series 1998-1B-O (the
"Trust") created pursuant to a Pass Through Trust Agreement, dated as of October
6, 1998 (the "Agreement"), between Wilmington Trust Company (the "Trustee") and
America West Airlines, Inc., a corporation incorporated under Delaware law (the
"Company"), a summary of certain of the pertinent provisions of which is set
forth below. To the extent not otherwise defined herein, the capitalized terms
used herein have the meanings assigned to them in the Agreement. This
Certificate is one of the duly authorized Certificates designated as "7.12%
America West Airlines [Initial] [Exchange] Pass Through Certificates, Series
1998-1B-O" (herein called the "Certificates"). This Certificate is issued under
and is subject to the terms, provisions, and conditions of the Agreement. By
virtue of its acceptance hereof the Certificateholder of this Certificate
assents to and agrees to be bound by the provisions of the Agreement and the
Intercreditor Agreement. The property of the Trust includes an interest in
certain Equipment Notes and all rights of the Trust to receive payments under
the Intercreditor Agreement and any Liquidity Facility (the "Trust Property").
Each issue of the Equipment Notes is secured by, among other things, a security
interest in the Aircraft leased to or owned by the Company.

- ----------

         *        To be included on the face of each Global Certificate.
<PAGE>   68
                                      A-4


                  The Certificates represent fractional undivided interests in
the Trust and the Trust Property, and have no rights, benefits or interest in
respect of any assets or property other than the Trust Property.

                  Subject to and in accordance with the terms of the Agreement
and the Intercreditor Agreement, from and to the extent of funds then available
to the Trustee, there will be distributed on each January 2 and July 2 (a
"Regular Distribution Date"), commencing on January 2, 1999, to the Person in
whose name this Certificate is registered at the close of business on the 15th
day preceding the Regular Distribution Date, an amount in respect of the
Scheduled Payments due on such Regular Distribution Date on the Equipment Notes,
the receipt of which has been confirmed by the Trustee, equal to the product of
the percentage interest in the Trust evidenced by this Certificate and an amount
equal to the sum of such Scheduled Payments. Subject to and in accordance with
the terms of the Agreement and the Intercreditor Agreement, in the event that
Special Payments on the Equipment Notes are received by the Trustee, from funds
then available to the Trustee, there shall be distributed on the applicable
Special Distribution Date, to the Person in whose name this Certificate is
registered at the close of business on the 15th day preceding the Special
Distribution Date, an amount in respect of such Special Payments on the
Equipment Notes, the receipt of which has been confirmed by the Trustee, equal
to the product of the percentage interest in the Trust evidenced by this
Certificate and an amount equal to the sum of such Special Payments so received.
If a Regular Distribution Date or Special Distribution Date is not a Business
Day, distribution shall be made on the immediately following Business Day with
the same force and effect as if made on such Regular Distribution Date or
Special Distribution Date and no interest shall accrue during the intervening
period. The Trustee shall mail notice of each Special Payment and the Special
Distribution Date therefor to the Certificateholder of this Certificate.

                  The Certificates do not represent a direct obligation of, or
an obligation guaranteed by, or an interest in, the Company or the Trustee or
any of their affiliates. The Certificates are limited in right or payment, all
as more specifically set forth on the face hereof and in the Agreement. All
payments or distributions made to Certificateholders under the Agreement shall
be made only from the Trust Property and only to the extent that the Trustee
shall have sufficient income or proceeds from the Trust Property to make such
payments in accordance with the terms of the Agreement. Each Certificate-holder
of this Certificate, by its acceptance hereof, agrees that it will look solely
to the income and proceeds from the Trust Property to the extent available for
distribution to such Certificateholder as provided in the Agreement. This
Certificate does not purport to summarize the Agreement and reference is made to
the Agreement for information with respect to the interests, rights, benefits,
obligations, proceeds, and duties evidenced hereby. A copy of the Agreement may
be examined during normal business hours at the principal office of the Trustee,
and at such other places, if any, designated by the Trustee, by any
Certificateholder upon request.

                  The Agreement permits, with certain exceptions therein
provided, the amendment thereof and the modification of the rights and
obligations of the Company and the rights of the Certificateholders under the
Agreement at any time by the Company and the Trustee with the consent of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not less than a majority in interest in the Trust. Any
such consent by the Certificateholder of this Certificate shall be conclusive
and binding on such Certificateholder and
<PAGE>   69
                                      A-5


upon all future Certificateholders of this Certificate and of any Certificate
issued upon the transfer hereof or in exchange hereof or in lieu hereof whether
or not notation of such consent is made upon this Certificate. The Agreement
also permits the amendment thereof, in certain limited circumstances, without
the consent of the Certificateholders of any of the Certificates.

                  As provided in the Agreement and subject to certain
limitations therein set forth, the transfer of this Certificate is registrable
in the Register upon surrender of this Certificate for registration of transfer
at the offices or agencies maintained by the Trustee in its capacity as
Registrar, or by any successor Registrar, in the Borough of Manhattan, the City
of New York, duly endorsed or accompanied by a written instrument of transfer in
form satisfactory to the Trustee and the Registrar duly executed by the
Certificateholder hereof or such Certificateholder's attorney duly authorized in
writing, and thereupon one or more new Certificates of authorized denominations
evidencing the same aggregate Fractional Undivided Interest in the Trust will be
issued to the designated transferee or transferees.

                  [The Holder of this Certificate is entitled to the benefits of
the Exchange and Registration Rights Agreement, dated as of October 6, 1998,
among the Company, the Trustee and the Initial Purchasers named therein (the
"Registration Rights Agreement"). In the event that no Registration Event has
occurred on or prior to the 210th day after the date of the issuance of the
Certificates, the interest rate per annum payable in respect of the Equipment
Notes and the Deposits shall be increased by 0.50%, from and including the 210th
day after the Issuance Date to but excluding the earlier of (i) the date on
which a Registration Event occurs and (ii) the date on which there cease to be
any Registrable Certificates (as defined in the Registration Rights Agreement).
In the event that the Shelf Registration Statement ceases to be effective at any
time during the period specified by Section 2(b)(B) of the Registration Rights
Agreement for more than 60 days, whether or not consecutive, during any 12-month
period, the interest rate per annum payable in respect of the Equipment Notes
and the Deposits shall be increased by 0.50% from the 61st day of the applicable
12-month period such Shelf Registration Statement ceases to be effective until
such time as the Shelf Registration Statement again becomes effective ( or, if
earlier, the end of the period specified by Section 2(b)(B) of the Registration
Rights Agreement).]*

                  Except as otherwise provided in the Agreement and
notwithstanding the above, the final distribution on this Certificate will be
made after notice mailed by the Trustee of the pendency of such distribution and
only upon presentation and surrender of this Certificate at the office or agency
of the Trustee specified in such notice.

                  Under certain circumstances set forth in Section 11.01 of the
Agreement, all of the Trustee's right, title and interest to the Trust Property
may be assigned, transferred and delivered to the Related Trustee of the Related
Trust pursuant to the Assignment and Assumption Agreement. Upon the
effectiveness of such Assignment and Assumption Agreement (the

         *        To be included only on each Initial Certificate.
<PAGE>   70
                                      A-6


"Transfer"), the Trust shall be terminated, the Certificateholders shall receive
beneficial interests in the Related Trust in exchange for their interests in the
Trust equal to their respective beneficial interests in the Trust, the
Certificates representing Fractional Undivided Interests in the Trust shall be
deemed for all purposes of the Agreement and the Related Pass Through Trust
Agreement to be certificates representing the same fractional undivided
interests in the Related Trust and its trust property. Each Certificateholder,
by its acceptance of this Certificate or a beneficial interest herein, agrees to
be bound by the Assignment and Assumption Agreement and subject to the terms of
the Related Pass Through Trust Agreement as a certificateholder thereunder. From
and after the Transfer, unless and to the extent the context otherwise requires,
references herein to the Trust, the Agreement and the Trustee shall constitute
references to the Related Trust, the Related Pass Through Trust Agreement and
trustee of the Related Trust, respectively.

                  The Certificates are issuable only as registered Certificates
without coupons in minimum denominations of [$100,000]* [$1,000]** Fractional
Undivided Interest and integral multiples of $1,000 in excess thereof except
that one Certificate may be in a different denomination. As provided in the
Agreement and subject to certain limitations therein set forth, the Certificates
are exchangeable for new Certificates of authorized denominations evidencing the
same aggregate Fractional Undivided Interest in the Trust, as requested by the
Certificateholder surrendering the same.

                  No service charge will be made for any such registration of
transfer or exchange, but the Trustee shall require payment by the Holder of a
sum sufficient to cover any tax or governmental charge payable in connection
therewith.

                  Each Certificateholder or Investor that is not a United States
person within the meaning of Section 7701(a)(30) of the Internal Revenue Code,
as amended, by its acceptance of a Certificate or a beneficial interest therein,
agrees to indemnify and hold harmless the Trust and the Trustee from and against
any improper failure to withhold taxes from amounts payable to it or for its
benefit. Each Certificateholder and Investor, by its acceptance of this
Certificate or a beneficial interest herein, agrees to treat the Trust as a
grantor trust for all U.S. federal, state and local income tax purposes.

                  The Trustee, the Registrar, and any agent of the Trustee or
the Registrar may treat the person in whose name this Certificate is registered
as the owner hereof for all purposes, and neither the Trustee, the Registrar,
nor any such agent shall be affected by any notice to the contrary.

                  The obligations and responsibilities created by the Agreement
and the Trust created thereby shall terminate upon the distribution to
Certificateholders of all amounts required

         *        To be included only on each Initial Certificate.

         **       To be included only on each Exchange Certificate.
<PAGE>   71
                                      A-7


to be distributed to them pursuant to the Agreement and the disposition of all
property held as part of the Trust Property.

                  UNTIL THE TRANSFER, THE AGREEMENT AND THIS CERTIFICATE SHALL
BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF
DELAWARE AND THE OBLIGATIONS, RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER SHALL
BE DETERMINED IN ACCORDANCE WITH SUCH LAWS. FROM AND AFTER THE TRANSFER, THE
AGREEMENT AND THIS CERTIFICATE SHALL BE GOVERNED AND CONSTRUED IN ACCORDANCE
WITH THE LAWS OF THE STATE OF NEW YORK AND THE OBLIGATIONS, RIGHTS AND REMEDIES
OF THE PARTIES HEREUNDER SHALL BE DETERMINED IN ACCORDANCE WITH SUCH LAWS.

                  Unless the certificate of authentication hereon has been
executed by the Trustee, by manual signature, this Certificate shall not be
entitled to any benefit under the Agreement or be valid for any purpose.
<PAGE>   72
                                      A-8


                  IN WITNESS WHEREOF, the Trustee has caused this Certificate to
be duly executed.

Dated: October 6, 1998

                                         AMERICA WEST AIRLINES PASS THROUGH
                                           TRUST, SERIES 1998-1B-O

                                         By: WILMINGTON TRUST COMPANY,not in its
                                             individual capacity
                                             but solely as Trustee

                                         By: ___________________________________
                                             Name:
                                             Title:

[Attest:

- ----------------------
Authorized Signature]
<PAGE>   73
                                      A-9


              [FORM OF THE TRUSTEE'S CERTIFICATE OF AUTHENTICATION]

                    This is one of the Certificates referred
                      to in the within-mentioned Agreement.

                            WILMINGTON TRUST COMPANY,
                            not in its individual capacity but solely as Trustee

                            By: ________________________________________________
                                Authorized Officer
<PAGE>   74
                                      A-10


                             FORM OF TRANSFER NOTICE

                  FOR VALUE RECEIVED the undersigned registered holder hereby
sell(s), assign(s) and transfer(s) unto

Insert Taxpayer Identification No.

____________________

____________________

please print or typewrite name and address including zip code of assignee

____________________

the within Certificate and all rights thereunder, hereby irrevocably
constituting and appointing

____________________

attorney to transfer said Certificate on the books of the Trustee with full
power of substitution in the premises.

                     [THE FOLLOWING PROVISION TO BE INCLUDED
                               ON ALL CERTIFICATES
                         EXCEPT REGULATION S GLOBAL AND
                      REGULATION S DEFINITIVE CERTIFICATES]

                  In connection with any transfer of this Certificate occurring
prior to the date that is the earlier of the date of an effective Registration
Statement or the date two years after the later of the original issuance of this
Certificate or the last date on which this Certificate was held by America West
Airlines, Inc., the Trustee or any affiliate of such Persons, the undersigned
confirms that without utilizing any general solicitation or general advertising
that:

                                   [Check One]

[ ] (a) this Certificate is being transferred in compliance with the exemption
from registration under the Securities Act of 1933, as amended, provided by Rule
144A thereunder.

                                       or

[ ] (b) this Certificate is being transferred other than in accordance with (a)
above and documents are being furnished that comply with the conditions of
transfer set forth in this Certificate and the Agreement.

If neither of the foregoing boxes is checked, the Trustee or other Registrar
shall not be obligated to register this Certificate in the name of any Person
other than the Holder hereof unless and until the conditions to any such
transfer of registration set forth herein and in Section 3.06 of the Agreement
shall have been satisfied.
<PAGE>   75
                                      A-11

Date:__________________                              [Name of Transferor]

                                                     NOTE: The signature must
                                                     correspond with the name as
                                                     written upon the face of
                                                     the within-mentioned
                                                     instrument in every
                                                     particular, without
                                                     alteration or any change
                                                     whatsoever.

Signature Guarantee: ______________________

TO BE COMPLETED BY PURCHASER IF (a) ABOVE IS CHECKED.

                  The undersigned represents and warrants that it is purchasing
this Certificate for its own account or an account with respect to which it
exercises sole investment discretion and that it and any such account is a
"qualified institutional buyer" within the meaning of Rule 144A under the
Securities Act of 1933, as amended, and is aware that the sale to it is being
made in reliance on Rule 144A and acknowledges that it has received such
information regarding the Company as the undersigned has requested pursuant to
Rule 144A or has determined not to request such information and that it is aware
that the transferor is relying upon the undersigned's foregoing representations
in order to claim the exemption from registration provided by Rule 144A.

Dated:__________________           _____________________________
                                   NOTE: To be executed by an executive officer.
<PAGE>   76
                                                                       EXHIBIT B

             FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION WITH
               TRANSFERS OF CERTIFICATES PURSUANT TO REGULATION S

                                                                          [date]

Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE  19890-0001

Attention:  Corporate Trust Trustee Administration

         Re:      America West Airlines Pass Through Trust (the "Trust"), Series
                  1998-1B-O, America West Airlines Pass Through Certificates,
                  Series 1998-1B-O (the "Certificates")

Sirs:

                  In connection with our proposed sale of $_____ Fractional
Undivided Interest of the Certificates, we confirm that such sale has been
effected pursuant to and in accordance with Regulation S under the Securities
Act of 1933, as amended, and, accordingly, we represent that:

                  (1) the offer of the Certificates was not made to a person in
         the United States or to or for the account or benefit of a U.S. person;

                  (2) either (a) at the time the buy order was originated, the
         transferee was outside the United States or we and any person acting on
         our behalf reasonably believed that the transferee was outside the
         United States or (b) the transaction was executed in, on or through the
         facilities of a designated off-shore securities market and neither we
         nor any person acting on our behalf knows that the transaction has been
         pre-arranged with a buyer in the United States;

                  (3) no directed selling efforts have been made in the United
         States in contravention of the requirements of Rule 903(a) or Rule
         904(a) of Regulation S, as applicable; and

                  (4) the transaction is not part of a plan or scheme to evade
         the registration requirements of the Securities Act.

                  In addition, if the sale is made during a restricted period
and the provisions of Rule 903(b)(2) or Rule 904(b)(1) of Regulation S are
applicable thereto, we confirm that such sale has been made in accordance with
the applicable provisions of Rule 903(b)(2) or Rule 904(b)(1), as the case may
be.

                  You and America West Airlines, Inc. are entitled to rely upon
this letter and are irrevocably authorized to produce this letter or a copy
hereof to any interested party in any
<PAGE>   77
                                       B-2


administrative or legal proceedings or official inquiry with respect to the
matters covered hereby. Terms used in this certificate have the meanings set
forth in Regulation S.

                                                     Very truly yours,

                                                     [Name of Transferor]
<PAGE>   78
                                                                       EXHIBIT C

                FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION
                        WITH TRANSFERS OF CERTIFICATES TO
                   NON-QIB INSTITUTIONAL ACCREDITED INVESTORS

                                                      [date]

Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE  19890-0001

Attention:  Corporate Trust Trustee Administration

America West Airlines, Inc.
4000 East Sky Harbor Boulevard
Phoenix, Arizona 85043

                              AMERICA WEST AIRLINES
               PASS THROUGH TRUST, SERIES 1998-1B-O (the "Trust")
                   Pass Through Certificates, Series 1998-1B-O
                              (the "Certificates")

Ladies and Gentlemen:

         In connection with our proposed purchase of U.S. $[_____________]
Fractional Undivided Interest of Certificates, we confirm that:

         1. We understand that any subsequent transfer of the Certificates is
subject to certain restrictions and conditions set forth in the Pass Through
Trust Agreement, dated as of October 6, 1998, between America West Airlines,
Inc. (the "Company") and Wilmington Trust Company (the "Trustee") relating to
the Certificates, and we agree to be bound by, and not to resell, pledge or
otherwise transfer the Certificates except in compliance with, such restrictions
and conditions and the Securities Act of 1933, as amended (the "Securities
Act").

         2. We are purchasing Certificates having an aggregate principal amount
of not less than $100,000 and each account (if any) for which we are purchasing
Certificates is purchasing Certificates having an aggregate principal amount of
not less than $100,000.

         3. We understand that the Certificates have not been registered under
the Securities Act, that the Certificates are being sold to us in a transaction
that is exempt from the registration requirements of the Securities Act and that
the Certificates may not be offered or resold except as permitted in the
following sentence. We agree, on our own behalf and on behalf of any accounts
for which we are acting as hereinafter stated, that, if we should sell any
Certificates within two
<PAGE>   79
                                       C-2


years after the later of the original issuance of such Certificate and the last
date on which such Certificate is owned by the Company, the Trustee or any
affiliate of any of such persons, we will do so only (A) to the Company, (B) in
accordance with Rule 144A under the Securities Act to a "qualified institutional
buyer" (as defined therein), (C) outside the United States in accordance with
Rule 904 of Regulation S under the Securities Act, (D) pursuant to the exemption
from registration provided by Rule 144 under the Securities Act or (E) pursuant
to an effective registration statement under the Securities Act, and we further
agree to provide to any person purchasing any of the Certificates from us a
notice advising such purchaser that resales of the Certificates are restricted
as stated herein.

         4. We understand that, on any proposed resale of any Certificates, we
will be required to furnish to the Company and the Trustee such certifications,
legal opinions and other information as the Company and the Trustee may
reasonably require to confirm that the proposed sale complies with the foregoing
restrictions. We further understand that the Certificates purchased by us will
bear a legend to the foregoing effect.

         5. We are an institutional "accredited investor" (as defined in Rule
501(a)(1), (2), (3) or (7) of Regulation D under the Securities Act) and have
such knowledge and experience in financial and business matters as to be capable
of evaluating the merits and risks of our investment in the Certificates, and we
and any accounts for which we are acting are each able to bear the economic risk
of our or their investments.

         6. We are acquiring the Certificates purchased by us for our own
account or for one or more accounts (each of which is an institutional
"accredited investor") as to each of which we exercise sole investment
discretion and not with a view to any distribution of the Certificates, subject,
nevertheless to the understanding that the disposition of our property shall at
all times be and remain within our control.

                  You are entitled to rely upon this letter and are irrevocably
authorized to produce this letter or a copy thereof to any interested party in
any administrative or legal proceedings or official inquiry with respect to the
matters covered hereby.

                                                     Very truly yours,

                                                     By: _______________________
                                                         Name:
                                                         Title:
<PAGE>   80
                                                                       EXHIBIT D

                   FORM OF ASSIGNMENT AND ASSUMPTION AGREEMENT
            America West Airlines Pass Through Trust, Series 1998-1B

                  ASSIGNMENT AND ASSUMPTION AGREEMENT, dated ____________, 199_
(the "Agreement"), between Wilmington Trust Company, a Delaware banking
corporation ("WTC"), not in its individual capacity except as expressly provided
herein, but solely as trustee under the Pass Through Trust Agreement dated as of
October 6, 1998 (as amended, modified or otherwise supplemented from time to
time, the "Pass Through Trust Agreement") in respect of the America West
Airlines Pass Through Trust, Series 1998-1B-O (the "Assignor"), and Wilmington
Trust Company, a Delaware banking corporation, not in its individual capacity
except as expressly provided herein, but solely as trustee under the Pass
Through Trust Agreement dated as of October 6, 1998 (the "New Pass Through Trust
Agreement") in respect of the America West Airlines Pass Through Trust, Series
1998-1B-S (the "Assignee").

                              W I T N E S S E T H:

                  WHEREAS, the parties hereto desire to effect on the date
hereof (the "Transfer Date") (a) the transfer by the Assignor to the Assignee of
all of the right, title and interest of the Assignor in, under and with respect
to, among other things, the Trust Property and each of the documents listed in
Schedule I hereto (the "Scheduled Documents") and (b) the assumption by the
Assignee of the obligations of the Assignor (i) under the Scheduled Documents
and (ii) in respect of the Certificates issued under the Pass Through Trust
Agreement; and

                  WHEREAS, the Scheduled Documents permit such transfer upon
satisfaction of certain conditions heretofore or concurrently herewith being
complied with;

                  NOW, THEREFORE, in consideration of the premises and of the
mutual covenants and agreements herein contained, the parties hereto do hereby
agree as follows (capitalized terms used herein without definition having the
meaning ascribed thereto in the Pass Through Trust Agreement):

                  1. Assignment. The Assignor does hereby sell, assign, convey,
transfer and set over unto the Assignee as of the Transfer Date all of its
present and future right, title and interest in, under and with respect to the
Trust Property and the Scheduled Documents and each other contract, agreement,
document or instrument relating to the Trust Property or the Scheduled Documents
(such other contracts, agreements, documents or instruments, together with the
Scheduled Documents, to be referred to as the "Assigned Documents"), and any
proceeds therefrom, together with all documents and instruments evidencing any
of such right, title and interest.

                  2. Assumption. The Assignee hereby assumes for the benefit of
the Assignor and each of the parties listed in Schedule II hereto (collectively,
the "Beneficiaries") all of the duties and obligations of the Assignor, whenever
accrued, pursuant to the Assigned Documents and hereby confirms that it shall be
deemed a party to each of the Assigned Documents to which the Assignor is a
party and shall be bound by all the terms thereof (including the agreements and
obligations of the Assignor set forth therein) as if therein named as the
Assignor. Further, the Assignee hereby assumes for the benefit of the Assignor
and the Beneficiaries all of the duties
<PAGE>   81
                                       D-2


and obligations of the Assignor under the Outstanding Certificates and hereby
confirms that the Certificates representing Fractional Undivided Interests under
the Pass Through Trust Agreement shall be deemed for all purposes of the Pass
Through Trust Agreement and the New Pass Through Trust Agreement to be
certificates representing the same fractional undivided interests under the New
Pass Through Trust Agreement equal to their respective beneficial interests in
the trust created under the Pass Through Trust Agreement.

                  3. Effectiveness. This Agreement shall be effective upon the
execution and delivery hereof by the parties hereto, and each Certificateholder,
by its acceptance of its Certificate or a beneficial interest therein, agrees to
be bound by the terms of this Agreement.

                  4. Payments. The Assignor hereby covenants and agrees to pay
over to the Assignee, if and when received following the Transfer Date, any
amounts (including any sums payable as interest in respect thereof) paid to or
for the benefit of the Assignor that, under Section 1 hereof, belong to the
Assignee.

                  5. Further Assurances. The Assignor shall, at any time and
from time to time, upon the request of the Assignee, promptly and duly execute
and deliver any and all such further instruments and documents and take such
further action as the Assignee may reasonably request to obtain the full
benefits of this Agreement and of the right and powers herein granted. The
Assignor agrees to deliver the Global Certificates, and all Trust Property, if
any, then in the physical possession of the Assignor, to the Assignee.

                  6. Representations and Warranties. (a) The Assignee represents
and warrants to the Assignor and each of the Beneficiaries that:

                  (i) it has all requisite power and authority and legal right
         to enter into and carry out the transactions contemplated hereby and to
         carry out and perform the obligations of the "Pass Through Trustee"
         under the Assigned Documents;

                  (ii) on and as of the date hereof, the representations and
         warranties of the Assignee set forth in Section 7.15 of the New Pass
         Through Trust Agreement are true and correct.

                  (b) The Assignor represents and warrants to the Assignee that:

                  (i) it is duly incorporated, validly existing and in good
         standing under the laws of the State of Delaware and has the full trust
         power, authority and legal right under the laws of the State of
         Delaware and the United States pertaining to its trust and fiduciary
         powers to execute and deliver this Agreement;

                  (ii) the execution and delivery by it of this Agreement and
         the performance by it of its obligations hereunder have been duly
         authorized by it and will not violate its articles of association or
         by-laws or the provisions of any indenture, mortgage, contract or other
         agreement to which it is a party or by which it is bound; and

                  (iii) this Agreement constitutes the legal, valid and binding
         obligations of it enforceable against it in accordance with its terms,
         except as the same may be limited by applicable bankruptcy, insolvency,
         reorganization, moratorium or similar laws affecting
<PAGE>   82
                                       D-3


         the rights of creditors generally and by general principles of equity,
         whether considered in a proceeding at law or in equity.

                  7. GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK INCLUDING MATTERS
OF CONSTRUCTION, VALIDITY AND PERFORMANCE, WITHOUT GIVING EFFECT TO PRINCIPLES
OF CONFLICTS OF LAWS.

                  8. Counterparts. This Agreement may be executed in any number
of counterparts, all of which together shall constitute a single instrument. It
shall not be necessary that any counterpart be signed by both parties so long as
each party shall sign at least one counterpart.

                  9. Third Party Beneficiaries. The Assignee hereby agrees, for
the benefit of the Beneficiaries, that its representations, warranties and
covenants contained herein are also intended to be for the benefit of each
Beneficiary, and each Beneficiary shall be deemed to be an express third party
beneficiary with respect thereto, entitled to enforce directly and in its own
name any rights or claims it may have against such party as such beneficiary.

                  IN WITNESS WHEREOF, the parties hereto, through their
respective officers thereunto duly authorized, have duly executed this
Assignment as of the day and year first above written.

                                    ASSIGNOR:

                                    WILMINGTON TRUST COMPANY, not in its
                                    individual capacity except as expressly
                                    provided herein, but solely as trustee under
                                    the Pass Through Trust Agreement in respect
                                    of the America West Airlines Pass Through
                                    Trust 1998-1B-O

                                    By: ________________________________________
                                        Title:

                                    ASSIGNEE:

                                    WILMINGTON TRUST COMPANY, not in its
                                    individual capacity except as expressly
                                    provided herein, but solely as trustee under
                                    the Pass Through Trust Agreement in respect
                                    of the America West Airlines Pass Through
                                    Trust 1998-1B-S

                                    By: ________________________________________
                                        Title:
<PAGE>   83
                                                                      Schedule I

                         Schedule of Assigned Documents

(1)      Intercreditor Agreement dated as of October 6, 1998 among the Trustee,
         the Other Trustees, the Liquidity Provider, the liquidity provider, if
         any, relating to the Certificates issued under (and as defined in) each
         of the Other Pass Through Trust Agreements and the Subordination Agent.

(2)      Registration Rights Agreement dated as of October 6, 1998 among the
         Initial Purchasers, the Trustee, the Other Trustees, and the Company.

(3)      Escrow and Paying Agent Agreement (Class A) dated as of October 6, 1998
         among the Escrow Agent, the Initial Purchasers, the Trustee and the
         Paying Agent.

(4)      Note Purchase Agreement dated as of October 6, 1998 among the Company,
         the Trustee, the Other Trustees, the Depositary, the Escrow Agent, the
         Paying Agent and the Subordination Agent.

(5)      Deposit Agreement (Class A) dated as of October 6, 1998 between the
         Escrow Agent and the Depositary.

(6)      Each of the Operative Agreements (as defined in the Participation
         Agreement for each Aircraft) in effect as of the Transfer Date.
<PAGE>   84
                                                                     Schedule II

                            Schedule of Beneficiaries

Wilmington Trust Company, not in its individual capacity but solely as
Subordination Agent.

Wilmington Trust Company, not in its individual capacity but solely as Paying
Agent

ABN AMRO Bank, N.V., acting through its Chicago branch, as Liquidity Provider

America West Airlines, Inc.

Morgan Stanley & Co. Incorporated, as Initial Purchaser

Donaldson, Lufkin & Jenrette Securities Corporation, as Initial Purchaser

Merrill Lynch, Pierce, Fenner & Smith Incorporated, as Initial Purchaser

Salomon Smith Barney Inc., as Initial Purchaser

Wilmington Trust Company, as Escrow Agent

Each of the other parties to the Assigned Documents
<PAGE>   85
                                                                       EXHIBIT E

            FORM OF NOTICE TO DESIGNATE NOMINEE AS WITHHOLDING AGENT
          (Treas. Reg. Section 1.1445-8(f); 17 C.F.R. 240.10b-17(b)(1))

                                                                          [DATE]

National Association of
Securities Dealers, Inc.
Market Operations
80 Merritt Blvd.
Trumbull, CT  06611

         Re:      America West Airlines Pass Through Trust, Series 1998-1B-O
                  Pass Through Certificates, Series 1998-1B-O

                  With respect to distributions to be made on [INSERT
DISTRIBUTION DATE] to holders of the above-referenced Pass Through Certificates
in the amount of $ ____ per $1,000 principal amount of Certificate, we hereby
designate the appropriate nominees to withhold from amounts distributable to any
non-U.S. Person such amounts as required by Section 1446 of the Internal Revenue
Code of 1986, as amended. The term "non-U.S. Person" means any person or entity
that, for U.S. federal income tax purposes, is not a "U.S. Person." "U.S.
Person" for this purpose means a citizen or resident of the United States, a
corporation, partnership or other entity created or organized under the laws of
the United States or any political subdivision thereof, or an estate or trust,
the income of which is subject to U.S. federal income taxation regardless of its
source. The date of record for determining holders of Certificates entitled to
receive the distribution on [INSERT DISTRIBUTION DATE] is [INSERT RELATED RECORD
DATE].

                                                      Very truly yours,

<PAGE>   1
                                                                     Exhibit 4.7













                          PASS THROUGH TRUST AGREEMENT

                           Dated as of October 6, 1998

                                     between

                           AMERICA WEST AIRLINES, INC.

                                       And

                            WILMINGTON TRUST COMPANY,

                                   as Trustee

           America West Airlines Pass Through Trust, Series 1998-1B-S

            7.12% Initial Pass Through Certificates, Series 1998-1B-S
           7.12% Exchange Pass Through Certificates, Series 1998-1B-S
<PAGE>   2
Reconciliation and tie between America West Airlines Pass Through Trust
Agreement, Series 1998-1B-S dated as of October 6, 1998, and the Trust Indenture
Act of 1939. This reconciliation does not constitute part of the Pass Through
Trust Agreement.

<TABLE>
<CAPTION>
          Trust Indenture Act                      Pass Through Trust
             of 1939 Section                        Agreement Section
             ---------------                        -----------------
<S>                                                <C>
            310(a)(1)                                   7.08
               (a)(2)                                   7.08
            312(a)                                      3.05; 8.01; 8.02
            313(a)                                      7.06; 8.03
            314(a)                                      8.04(a),(c) & (d)
            (a)(4)                                      8.04(e)
            (c)(1)                                      1.02
            (c)(2)                                      1.02
            (d)(1)                                      7.13; 11.01
            (d)(2)                                      7.13; 11.01
            (d)(3)                                      2.01
            (e)                                         1.02
            315(b)                                      7.02
            316(a)(last sentence)                       1.04(c)
                (a)(1)(A)                               6.04
                (a)(1)(B)                               6.05
                (b)                                     6.06
                (c)                                     1.04(e)
            317(a)(1)                                   6.03
                (b)                                     7.13
            318(a)                                      12.06
</TABLE>
<PAGE>   3
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
SECTION                                                                   PAGE
<S>                                                                       <C>
ARTICLE I DEFINITIONS........................................................2
      Section 1.01.     Definitions..........................................2
      Section 1.02.     Compliance Certificates and Opinions................13
      Section 1.03.     Form of Documents Delivered to Trustee..............14
      Section 1.04.     Directions of Certificateholders....................14

ARTICLE II  ACQUISITION OF TRUST PROPERTY...................................15
      Section 2.01.     Acquisition of Trust Property.......................15
      Section 2.02.     Acceptance by Trustee...............................16
      Section 2.03.     Limitation of Powers................................16

ARTICLE III  THE CERTIFICATES...............................................16
      Section 3.01.     Title, Form, Denomination and Execution of
                        Certificates........................................16
      Section 3.02.     Restrictive Legends.................................19
      Section 3.03.     Authentication of Certificates......................20
      Section 3.04.     Transfer and Exchange...............................20
      Section 3.05.     Book-Entry Provisions for Restricted Global
                        Certificates and Regulation S Global
                        Certificates........................................21
      Section 3.06.     Special Transfer Provisions.........................23
      Section 3.07.     Mutilated, Destroyed, Lost or Stolen
                        Certificates........................................25
      Section 3.08.     Persons Deemed Owners...............................26
      Section 3.09.     Cancellation........................................26
      Section 3.10.     Temporary Certificates..............................26
      Section 3.11.     Limitation of Liability for Payments................27
      Section 3.12      ERISA Restrictive Legend ...........................27

ARTICLE IV  DISTRIBUTIONS; STATEMENTS TO CERTIFICATEHOLDERS.................27
      Section 4.01.     Certificate Account and Special Payments Account....27
      Section 4.02.     Distributions from Certificate Account and
                        Special Payments Account............................28
      Section 4.03.     Statements to Certificateholders....................29
      Section 4.04.     Investment of Special Payment Moneys................31

ARTICLE V  THE COMPANY......................................................31
      Section 5.01.     Maintenance of Corporate Existence..................31
      Section 5.02.     Consolidation, Merger, Etc..........................31

ARTICLE VI  DEFAULT.........................................................32
      Section 6.01.     Events of Default...................................32
      Section 6.02.     Incidents of Sale of Equipment Notes................34
      Section 6.03.     Judicial Proceedings Instituted by Trustee;
                        Trustee May Bring Suit..............................35
      Section 6.04.     Control by Certificateholders.......................35
</TABLE>
<PAGE>   4
<TABLE>
<CAPTION>
SECTION                                                                   PAGE
<S>                                                                       <C>
      Section 6.05.     Waiver of Past Defaults.............................35
      Section 6.06.     Right of Certificateholders to Receive Payments
                        Not to Be Impaired..................................36
      Section 6.07.     Certificateholders May Not Bring Suit Except
                        Under Certain Conditions............................36
      Section 6.08.     Remedies Cumulative.................................37

ARTICLE VII  THE TRUSTEE....................................................37
      Section 7.01.     Certain Duties and Responsibilities.................37
      Section 7.02.     Notice of Defaults..................................38
      Section 7.03.     Certain Rights of Trustee...........................38
      Section 7.04.     Not Responsible for Recitals or Issuance of
                        Certificates........................................39
      Section 7.05.     May Hold Certificates...............................39
      Section 7.06.     Money Held in Trust.................................39
      Section 7.07.     Compensation and Reimbursement......................39
      Section 7.08.     Corporate Trustee Required; Eligibility.............41
      Section 7.09.     Resignation and Removal; Appointment of
                        Successor...........................................41
      Section 7.10.     Acceptance of Appointment by Successor..............42
      Section 7.11.     Merger, Conversion, Consolidation or Succession
                        to Business.........................................43
      Section 7.12.     Maintenance of Agencies.............................43
      Section 7.13.     Money for Certificate Payments to Be Held in
                        Trust...............................................44
      Section 7.14.     Registration of Equipment Notes in Name of
                        Subordination Agent.................................44
      Section 7.15.     Representations and Warranties of Trustee...........45
      Section 7.16.     Withholding Taxes, Information Reporting............46
      Section 7.17.     Trustee's Liens.....................................46
      Section 7.18.     Preferential Collection of Claims...................46

ARTICLE VIII  CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE..............46
      Section 8.01.     The Company to Furnish Trustee with Names and
                        Addresses of Certificateholders.....................46
      Section 8.02.     Preservation of Information; Communications to
                        Certificateholders..................................47
      Section 8.03.     Reports by Trustee..................................47
      Section 8.04.     Reports by the Company..............................47

ARTICLE IX  SUPPLEMENTAL AGREEMENTS.........................................48
      Section 9.01.     Supplemental Agreements Without Consent of
                        Certificateholders..................................48
      Section 9.02.     Supplemental Agreements with Consent of
                        Certificateholders..................................49
      Section 9.03.     Documents Affecting Immunity or Indemnity...........50
      Section 9.04.     Execution of Supplemental Agreements................50
      Section 9.05.     Effect of Supplemental Agreements...................51
      Section 9.06.     Conformity with Trust Indenture Act.................51
      Section 9.07.     Reference in Certificates to Supplemental
                        Agreements..........................................51
</TABLE>

                                       ii
<PAGE>   5
<TABLE>
<CAPTION>
SECTION                                                                   PAGE
<S>                                                                       <C>
ARTICLE X  AMENDMENTS TO INDENTURES AND FINANCING DOCUMENTS.................51
      Section 10.01.    Amendments and Supplements to Indentures and
                        Financing Documents.................................51

ARTICLE XI  TERMINATION OF TRUST............................................52
      Section 11.01.    Termination of the Trust............................52

ARTICLE XII  MISCELLANEOUS PROVISIONS.......................................53
      Section 12.01.    Limitation on Rights of Certificateholders..........53
      Section 12.02.    Certificates Nonassessable and Fully Paid...........53
      Section 12.03.    Notices.............................................53
      Section 12.04.    Governing Law.......................................54
      Section 12.05.    Severability of Provisions..........................54
      Section 12.06.    Trust Indenture Act Controls........................54
      Section 12.07.    Effect of Headings and Table of Contents............55
      Section 12.08.    Successors and Assigns..............................55
      Section 12.09.    Benefits of Agreement...............................55
      Section 12.10.    Legal Holidays......................................55
      Section 12.11.    Counterparts........................................55
      Section 12.12.    Intention of Parties................................55
</TABLE>


Exhibit A - Form of Certificate to Request Removal of Restricted Legend
Exhibit B - Form of Certificate to be Delivered by an Institutional Accredited
            Investor

                                      iii
<PAGE>   6
                          PASS THROUGH TRUST AGREEMENT


            This PASS THROUGH TRUST AGREEMENT, dated as of October 6, 1998, (the
"Agreement") between AMERICA WEST AIRLINES, INC., a Delaware corporation, and
WILMINGTON TRUST COMPANY, as Trustee, is made with respect to the formation of
America West Airlines Pass Through Trust, Series 1998-1B-S and the 7.12% America
West Airlines Pass Through Trust, Series 1998-1B-S Pass Through Certificates
representing fractional undivided interests in the Trust.

                                   WITNESSETH:

            WHEREAS, the Company has obtained commitments from AVSA for the
delivery of certain Aircraft;

            WHEREAS, as of the Transfer Date, the Company will have financed (or
refinanced) the acquisition all or a portion of the Aircraft either (i) through
separate leveraged lease transactions in which the Company leases such aircraft
(collectively, the "Leased Aircraft") or (ii) through separate secured loan
transactions in which the Company owns such Aircraft (collectively, the "Owned
Aircraft");

            WHEREAS, as of the Transfer Date, in the case of each Leased
Aircraft, each Owner Trustee, acting on behalf of the corresponding Owner
Participant, will have issued pursuant to an Indenture, on a non-recourse basis,
three (or, subject to satisfaction of certain preconditions contained in the
Note Purchase Agreement, four) series of Equipment Notes in order to finance a
portion of its purchase price of such Leased Aircraft;

            WHEREAS, as of the Transfer Date, in the case of each Owned
Aircraft, the Company, will have issued pursuant to an Indenture, on a recourse
basis, three (or, subject to satisfaction of certain preconditions contained in
the Note Purchase Agreement, four) series of Equipment Notes to finance a
portion of the purchase price of such Owned Aircraft;

            WHEREAS, as of the Transfer Date, the Related Trustee will assign,
transfer and deliver all of such trustee's right, title and interest to the
trust property held by the Related Trustee to the Trustee pursuant to the
Assignment and Assumption Agreement;

            WHEREAS, the Trustee, effective only, but automatically, upon
execution and delivery of the Assignment and Assumption Agreement, will be
deemed to have declared the creation of the Trust for the benefit of the
Certificateholders, and each Holder of Certificates outstanding as of the
Transfer Date, as the grantors of the Trust, by their respective acceptances of
the Certificates, will join in the creation of this Trust with the Trustee;

            WHEREAS, all Certificates deemed issued by the Trust will evidence
fractional undivided interests in the Trust and will convey no rights, benefits
or interests in respect of any property other than the Trust Property except for
those Certificates to which an Escrow Receipt (as defined below) has been
affixed;
<PAGE>   7
                                      -2-

            WHEREAS, the Company has duly authorized the execution, delivery and
effectiveness of this Agreement as the "issuer", as such term is defined in and
solely for purposes of the Securities Act, of the Certificates deemed to be
issued pursuant hereto and as the "obligor", as such term is defined in and
solely for purposes of the Trust Indenture Act of 1939, as amended, with respect
to all such Certificates and is undertaking to perform certain administrative
and ministerial duties hereunder and is also undertaking to pay the ongoing fees
and expenses of the Trustee;

            WHEREAS, upon the execution and delivery of the Assignment and
Assumption Agreement, all of the conditions and requirements necessary to make
this Agreement a valid, binding and legal instrument, enforceable in accordance
with its terms and for the purposes herein expressed, will have been done,
performed and fulfilled, and the execution and delivery of this Agreement in the
form and with the terms hereof will have been in all respects duly authorized;
and

            WHEREAS, upon issuance of the Exchange Certificates, if any, or the
effectiveness of the Shelf Registration Statement, this Agreement, as amended or
supplemented from time to time, will be subject to the provisions of the Trust
Indenture Act of 1939, and shall, to the extent applicable, be governed by such
provisions;

            NOW, THEREFORE, in consideration of the mutual agreements herein
contained, and of other good and valuable consideration the receipt and adequacy
of which are hereby acknowledged, the parties hereto agree as follows:


                                    ARTICLE I

                                   DEFINITIONS

            Section 1.01. Definitions. For all purposes of this Agreement,
except as otherwise expressly provided or unless the context otherwise requires:

            (1) the terms used in this Agreement, including in the recitals to
this Agreement, that are defined in this Article have the meanings assigned to
them in this Article, and include the plural as well as the singular;

            (2) all other terms used herein which are defined in the Trust
Indenture Act, either directly or by reference therein, or by the rules
promulgated under the Trust Indenture Act, have the meanings assigned to them
therein;

            (3) all references in this Agreement to designated "Articles",
"Sections", "Subsections" and other subdivisions are to the designated Articles,
Sections, Subsections and other subdivisions of this Agreement;

            (4) the words "herein", "hereof" and "hereunder" and other words
of similar import refer to this Agreement as a whole and not to any particular
Article, Section, Subsection or other subdivision; and
<PAGE>   8
                                      -3-

            (5) unless the context otherwise requires, whenever the words
"including", "include" or "includes" are used herein, it shall be deemed to be
followed by the phrase "without limitation".

            Affiliate: Means, with respect to any specified Person, any other
      Person directly or indirectly controlling or controlled by or under direct
      or indirect common control with such Person. For the purposes of this
      definition, "control" means the power, directly or indirectly, to direct
      the management and policies of such Person, whether through the ownership
      of voting securities or by contract or otherwise, and the terms
      "controlling" and "controlled" have meanings correlative to the foregoing.

            Agent Members: Has the meaning specified in Section 3.05.

            Agreement: Has the meaning specified in the initial paragraph
      hereto.

            Aircraft: Has the meaning specified in the Note Purchase Agreement.

            Aircraft Purchase Agreement: Has the meaning specified in the Note
      Purchase Agreement.

            Assignment and Assumption Agreement: Means the assignment and
      assumption agreement substantially in the form of Exhibit D to the Related
      Trust to be executed and delivered in accordance with Section 11.01 of the
      Related Pass Through Trust Agreement.

            Authorized Agent: Means any Paying Agent or Registrar for the
      Certificates.

            Avoidable Tax: Means a state or local tax (i) upon (w) the Trust,
      (x) the Trust Property, (y) Certificateholders or (z) the Trustee for
      which the Trustee is entitled to seek reimbursement from the Trust
      Property, and (ii) which would be avoided if the Trustee were located in
      another state, or jurisdiction within a state, within the United States. A
      tax shall not be an Avoidable Tax if the Company or any Owner Trustee
      shall agree to pay, and shall pay, such tax.

            AVSA: Means AVSA S.A.R.L., an affiliate of Airbus Industrie G.I.E.

            Business Day: Means any day other than a Saturday, a Sunday or a day
      on which commercial banks are required or authorized to close in Phoenix,
      Arizona, New York, New York, Wilmington, Delaware or, so long as any
      Certificate is outstanding, the city and state in which the Trustee or any
      Loan Trustee maintains its Corporate Trust Office or receives and
      disburses funds.

            Cedel: Means Cedel Bank societe anonyme.

            Certificate: Means any one of the Initial Certificates or Exchange
      Certificates issued by the Related Trust and that are "Outstanding" (as
      defined in the Related Pass Through Trust Agreement) as of the Transfer
      Date (the "Transfer Date Certificates") and
<PAGE>   9
                                      -4-

      any such Initial Certificates or Exchange Certificates issued in exchange
      therefor or replacement thereof pursuant to this Agreement.

            Certificate Account: Means the account or accounts created and
      maintained pursuant to Section 4.01(a).

            Certificate Purchase Agreement: Means the Purchase Agreement dated
      September 24, 1998 among the Initial Purchasers and the Company, as the
      same may be amended, supplemented or otherwise modified from time to time
      in accordance with its terms.

            Certificateholder or Holder: Means the Person in whose name a
      Certificate is registered in the Register.

            Class D Certificateholder: Means, at any time, any holder of one or
      more pass through certificates issued by the America West Airlines Pass
      Through Trust, Series 1998-1D, if and when established.

            Company: Means America West Airlines, Inc., a Delaware corporation,
      or its successor in interest pursuant to Section 5.02, or (only in the
      context of provisions hereof, if any, where such reference is required for
      purposes of compliance with the Trust Indenture Act) any other "obligor"
      (within the meaning of the Trust Indenture Act) with respect to the
      Certificates.

            Controlling Party: Has the meaning specified in the Intercreditor
      Agreement.

            Corporate Trust Office: With respect to the Trustee or any Loan
      Trustee, means the office of such trustee in the city at which at any
      particular time its corporate trust business shall be principally
      administered.

            Definitive Certificates: Has the meaning specified in Section
      3.01(e).

            Delivery Period Termination Date: Has the meaning specified in the
      Related Pass Through Trust Agreement.

            Deposits: Has the meaning specified in the Deposit Agreement.

            Deposit Agreement: Means the Deposit Agreement dated as of October
      6, 1998 relating to the Certificates between the Depositary and the Escrow
      Agent, as the same may be amended, supplemented or otherwise modified from
      time to time in accordance with its terms.

            Depositary: Means ABN AMRO Bank N.V., acting through its Chicago
      branch.

            Direction: Has the meaning specified in Section 1.04(a).

            Distribution Date: Means any Regular Distribution Date or Special
      Distribution Date as the context requires.
<PAGE>   10
                                      -5-

            DTC: Means The Depository Trust Company, its nominees and their
      respective successors.

            EBO Date: Means the date set forth on Schedule 1 to the Lease as the
      "EBO Date".

            Equipment Notes: Means the equipment notes issued under the
      Indentures.

            ERISA: Means the Employee Retirement Income Security Act of 1974, as
      amended from time to time, or any successor federal statute.

            ERISA Legend: Has the meaning specified in Section 3.12.

            Escrow Agent: Means, initially, Wilmington Trust Company, and any
      replacement or successor therefor appointed in accordance with the Escrow
      Agreement.

            Escrow Agreement: Means the Escrow and Paying Agent Agreement dated
      as of October 6, 1998 relating to the Certificates, among the Escrow
      Agent, the Escrow Paying Agent, the Related Trustee (and after the
      Transfer Date, the Trustee) and the Initial Purchasers, as the same may be
      amended, supplemented or otherwise modified from time to time in
      accordance with its terms.

            Escrow Paying Agent: Means the Person acting as paying agent under
      the Escrow Agreement.

            Escrow Receipt: Means the receipt substantially in the form annexed
      to the Escrow Agreement representing a fractional undivided interest in
      the funds held in escrow thereunder.

            Euroclear: Means Morgan Guaranty Trust Company of New York, Brussels
      Office, as operator of the Euroclear System.

            Event of Default: Means an Indenture Default under any Indenture
      pursuant to which Equipment Notes held by the Trust were issued.

            Exchange Certificates: Means the pass through certificates issued in
      exchange for the Initial Certificates pursuant to the Registration Rights
      Agreement and authenticated under the Related Pass Through Trust Agreement
      (prior to the Transfer Date) or hereunder (after the Transfer Date).

            Exchange Offer: Means the exchange offer which may be made pursuant
      to the Registration Rights Agreement to exchange Initial Certificates for
      Exchange Certificates.

            Exchange Offer Registration Statement: Means the registration
      statement that, pursuant to the Registration Rights Agreement, is filed by
      the Company with the SEC with respect to the exchange of Initial
      Certificates for Exchange Certificates.

            Final Legal Distribution Date: Means July 2, 2018.
<PAGE>   11
                                      -6-

            Final Withdrawal: Has the meaning specified in the Escrow Agreement.

            Final Withdrawal Date: Has the meaning specified in the Escrow
      Agreement.

            Financing Documents: With respect to any Equipment Note, means (i)
      the Indenture and the Participation Agreement relating to such Equipment
      Note, and (ii) in the case of any Equipment Note related to a Leased
      Aircraft, the Lease relating to such Leased Aircraft.

            Fractional Undivided Interest: Means the fractional undivided
      interest in the Trust that is evidenced by a Certificate.

            Global Certificates: Has the meaning specified in Section 3.01(d).

            Global Exchange Certificate: Has the meaning specified in Section
      3.01(f).

            Indenture: Means each of the separate trust indentures and mortgages
      relating to the Aircraft, each as specified or described in a Delivery
      Notice delivered pursuant to the Note Purchase Agreement or the related
      Participation Agreement, in each case as the same may be amended,
      supplemented or otherwise modified from time to time in accordance with
      its terms.

            Indenture Default: With respect to any Indenture, means any Event of
      Default (as such term is defined in such Indenture).

            Initial Certificates: Means the "Initial Certificates" issued and
      authenticated under the Related Pass Through Trust Agreement, and any
      certificates issued and authenticated hereunder, in each case, other than
      the Exchange Certificates.

            Initial Purchasers: Means, collectively, Morgan Stanley & Co.
      Incorporated, Donaldson, Lufkin & Jenrette Securities Corporation, Merrill
      Lynch, Pierce, Fenner & Smith Incorporated and Salomon Smith Barney Inc.

            Institutional Accredited Investor: Means an institutional investor
      that is an "accredited investor" within the meaning set forth in Rule
      501(a)(1), (2), (3) or (7) of Regulation D under the Securities Act.

            Intercreditor Agreement: Means the Intercreditor Agreement dated as
      of October 6, 1998 among the Related Trustee (and after the Transfer Date,
      the Trustee), the Related Other Trustees (and after the Transfer Date, the
      Other Trustees), the Liquidity Provider, the liquidity provider relating
      to the Certificates issued under (and as defined in) each of the Related
      Other Pass Through Trust Agreements, and Wilmington Trust Company, as
      Subordination Agent and as trustee thereunder, as amended, supplemented or
      otherwise modified from time to time in accordance with its terms.

            Investors: Means the Initial Purchasers together with all subsequent
      beneficial owners of the Certificates.
<PAGE>   12
                                      -7-

            Issuance Date: Means the date of the issuance of the Initial
      Certificates.

            Lease: Means, with respect to each Leased Aircraft, the lease
      between an Owner Trustee, as the lessor, and the Company, as the lessee,
      referred to in the related Indenture, as such lease may be amended,
      supplemented or otherwise modified in accordance with its terms.

            Leased Aircraft: Has the meaning specified in the second recital to
      this Agreement.

            Liquidity Facility: Means, initially, the Revolving Credit Agreement
      dated as of October 6, 1998 relating to the Certificates, between the
      Liquidity Provider and the Subordination Agent, as agent and trustee for
      the Trustee, and, from and after the replacement of such Agreement
      pursuant to the Intercreditor Agreement, the replacement liquidity
      facility therefor, in each case as amended, supplemented or otherwise
      modified from time to time in accordance with their respective terms.

            Liquidity Provider: Means, initially, ABN AMRO Bank N.V., acting
      through its Chicago branch, and any replacement or successor therefor
      appointed in accordance with the Intercreditor Agreement.

            Loan Trustee: With respect to any Equipment Note or the Indenture
      applicable thereto, means the bank or trust company designated as trustee
      under such Indenture, together with any successor to such trustee
      appointed pursuant thereto.

            Material Adverse Tax Event: Has the meaning specified in Section
      17.3(a)(4) of the Lease.

            Non-U.S. Person: Means a Person that is not a "U.S. person", as
      defined in Regulation S.

            Note Purchase Agreement: Means the Note Purchase Agreement dated as
      of October 6, 1998 among the Related Trustee (and after the Transfer Date,
      the Trustee), the Related Other Trustees (and after the Transfer Date, the
      Other Trustees), the Company, the Escrow Agent, the Escrow Paying Agent
      and the Subordination Agent, as the same may be amended, supplemented or
      otherwise modified from time to time, in accordance with its terms.

            Offering Circular: Means the Offering Memorandum dated September 24,
      1998 relating to the offering of the Certificates and the other
      certificates under the Related Other Pass Through Trust Agreements.

            Officer's Certificate: Means a certificate signed, (a) in the case
      of the Company, by any Vice President or more senior officer of the
      Company or, (b) in the case of an Owner Trustee or a Loan Trustee, a
      Responsible Officer of such Owner Trustee or such Loan Trustee, as the
      case may be.
<PAGE>   13
                                      -8-

            Opinion of Counsel: Means a written opinion of legal counsel who (a)
      in the case of counsel for the Company may be (i) the General Counsel of
      the Company, (ii) Cooley Godward LLP, (iii) Vedder, Price, Kaufman,
      Kammholz & Day, or (iv) such other counsel designated by the Company and
      reasonably acceptable to the Trustee and (b) in the case of counsel for
      any Owner Trustee or any Loan Trustee may be such counsel as may be
      designated by any of them whether or not such counsel is an employee of
      any of them, and who shall be reasonably acceptable to the Trustee.

            Other Pass Through Trust Agreements: Means each of the two other
      America West Airlines 1998-1 Pass Through Trust Agreements relating to
      America West Airlines Pass Through Trust, Series 1998-1A-S and America
      West Airlines Pass Through Trust, Series 1998-1C-S, dated the date hereof.

            Other Trustees: Means the trustees under the Other Pass Through
      Trust Agreements, and any successor or other trustee appointed as provided
      therein.

            Other Trusts: Means the America West Airlines Pass Through Trust,
      Series 1998-1A-S and America West Airlines Pass Through Trust, Series
      1998-1C-S, created under the Other Pass Through Trust Agreements.

            Outstanding: When used with respect to Certificates, means, as of
      the date of determination, all Transfer Date Certificates, and all other
      Certificates theretofore authenticated and delivered under this Agreement,
      in each case except:

                         (i) Certificates theretofore canceled by the Registrar
            or delivered to the Trustee or the Registrar for cancellation;

                         (ii) Certificates for which money in the full amount
            required to make the final distribution with respect to such
            Certificates pursuant to Section 11.01 hereof has been theretofore
            deposited with the Trustee in trust for the Holders of such
            Certificates as provided in Section 4.01 pending distribution of
            such money to such Certificateholders pursuant to payment of such
            final distribution; and

                         (iii) Certificates in exchange for or in lieu of which
            other Certificates have been authenticated and delivered pursuant to
            this Agreement.

            Owned Aircraft: Has the meaning specified in the second recital to
      this Agreement.

            Owner Participant: With respect to any Equipment Note relating to a
      Leased Aircraft, means the "Owner Participant" as referred to in the
      Indenture pursuant to which such Equipment Note is issued and any
      permitted successor or assign of such Owner Participant; and Owner
      Participants at any time of determination means all of the Owner
      Participants thus referred to in the Indentures.

            Owner Trustee: With respect to any Equipment Note relating to a
      Leased Aircraft, means the "Owner Trustee", as referred to in the
      Indenture pursuant to which
<PAGE>   14
                                      -9-

      such Equipment Note is issued, not in its individual capacity but solely
      as trustee; and Owner Trustees means all of the Owner Trustees party to
      any of the Indentures.

            Participation Agreement: Means each Participation Agreement to be
      entered into by the Related Trustee pursuant to the Note Purchase
      Agreement, as the same may be amended, supplemented or otherwise modified
      in accordance with its terms.

            Paying Agent: Means the paying agent maintained and appointed for
      the Certificates pursuant to Section 7.12.

            Permitted Investments: Means obligations of the United States of
      America or agencies or instrumentalities thereof for the payment of which
      the full faith and credit of the United States of America is pledged,
      maturing in not more than 60 days after the date of acquisition thereof or
      such lesser time as is required for the distribution of any Special
      Payments on a Special Distribution Date.

            Person: Means any person, including any individual, corporation,
      limited liability company, partnership, joint venture, association,
      joint-stock company, trust, trustee, unincorporated organization, or
      government or any agency or political subdivision thereof.

            Pool Balance: Means, as of any date, (i) the original aggregate face
      amount of the "Certificates" as defined in the Related Pass Through Trust
      Agreement, less (ii) the aggregate amount of all payments made in respect
      of such Certificates other than payments made in respect of interest or
      premium thereon or reimbursement of any costs or expenses incurred in
      connection therewith less (iii) the aggregate amount of unused Deposits
      distributed as a Final Withdrawal other than payments in respect of
      interest or premium thereon. The Pool Balance as of any Distribution Date
      shall be computed after giving effect to the payment of principal, if any,
      on the Equipment Notes or other Trust Property held in such Trust and the
      distribution thereof to be made on such Distribution Date and the
      distribution of the Final Withdrawal to be made on such Distribution Date.

            Pool Factor: Means, as of any date, the quotient (rounded to the
      seventh decimal place) computed by dividing (i) the Pool Balance as at
      such date by (ii) the original aggregate face amount of the "Certificates"
      as defined in the Related Pass Through Trust Agreement. The Pool Factor as
      of any Distribution Date shall be computed after giving effect to the
      payment of principal, if any, on the Equipment Notes or other Trust
      Property and the distribution thereof to be made on such Distribution Date
      and the distribution of the Final Withdrawal to be made on such
      Distribution Date.

            PTC Event of Default: Means any failure to pay within 10 Business
      Days of the due date thereof: (i) the outstanding Pool Balance on the
      Final Legal Distribution Date or (ii) interest due on the Certificates on
      any Distribution Date (unless the Subordination Agent shall have made an
      Interest Drawing or Drawings (as defined in the Intercreditor Agreement),
      or a withdrawal or withdrawals pursuant to section 3.6(f) of the
      Intercreditor Agreement, with respect thereto in an aggregate amount
      sufficient to pay such interest and shall have distributed such amount to
      the Trustee).
<PAGE>   15
                                      -10-

            QIB: Means a qualified institutional buyer as defined in Rule 144A.

            Record Date: Means (i) for Scheduled Payments to be distributed on
      any Regular Distribution Date, other than the final distribution, the 15th
      day (whether or not a Business Day) preceding such Regular Distribution
      Date, and (ii) for Special Payments to be distributed on any Special
      Distribution Date, other than the final distribution, the 15th day
      (whether or not a Business Day) preceding such Special Distribution Date.

            Register and Registrar: Mean the register maintained and the
      registrar appointed pursuant to Sections 3.04 and 7.12.

            Registration Event: Means the declaration of the effectiveness by
      the SEC of the Exchange Offer Registration Statement or the Shelf
      Registration Statement.

            Registration Rights Agreement: Means the Exchange and Registration
      Rights Agreement dated as of October 6, 1998, among the Initial
      Purchasers, the Related Trustee (and after the Transfer Date, the
      Trustee), the Related Other Trustees (and after the Transfer Date, the
      Other Trustees) and the Company, as amended, supplemented or otherwise
      modified from time to time in accordance with its terms.

            Regular Distribution Date: With respect to distributions of
      Scheduled Payments in respect of the Certificates, means each date
      designated as a Regular Distribution Date in the Certificates issued
      pursuant to this Agreement, until payment of all the Scheduled Payments to
      be made under the Equipment Notes held in the Trust have been made;
      provided, however, that, if any such day shall not be a Business Day, the
      related distribution shall be made on the next succeeding Business Day
      without additional interest.

            Regulation S: Means Regulation S under the Securities Act or any
      successor regulation thereto.

            Regulation S Definitive Certificates: Has the meaning specified in
      Section 3.01(e).

            Regulation S Global Certificates: Has the meaning specified in
      Section 3.01(d).

            Related Other Pass Through Trust Agreements: Means the "Other Pass
      Through Trust Agreements" as defined in the Related Pass Through Trust
      Agreement.

            Related Other Trustee: Means the "Other Trustees" as defined in the
      Related Pass Through Trust Agreement.

            Related Other Trusts: Means the "Other Trusts" as defined in the
      Related Pass Through Trust Agreement.

            Related Pass Through Trust Agreement: Means the Pass Through Trust
      Agreement relating to America West Airlines Pass Through Trust, Series
      1998-1B-0, dated as of the date hereof, between the Company and the
      institution acting as trustee
<PAGE>   16
                                      -11-

      thereunder, as amended, supplemented or otherwise modified from time to
      time in accordance with its terms.

            Related Trust: Means the America West Pass Through Trust, Series
      1998-1B-O, formed under the Related Pass Through Trust Agreement.

            Related Trustee: Means the trustee under the Related Pass Through
      Trust Agreement.

            Responsible Officer: With respect to the Trustee, any Loan Trustee
      and any Owner Trustee, means any officer in the Corporate Trust Office of
      the Trustee, Loan Trustee or Owner Trustee or any other officer
      customarily performing functions similar to those performed by the persons
      who at the time shall be such officers, respectively, or to whom any
      corporate trust matter is referred because of his knowledge of and
      familiarity with a particular subject.

            Restricted Definitive Certificates: Has the meaning specified in
      Section 3.01(e).

            Restricted Global Certificate: Has the meaning specified in Section
      3.01(c).

            Restricted Legend: Has the meaning specified in Section 3.02.

            Restricted Period: Has the meaning specified in Section 3.01(d).

            Rule 144A: Means Rule 144A under the Securities Act and any
      successor rule thereto.

            Scheduled Payment: With respect to any Equipment Note, means (i) any
      payment of principal or interest on such Equipment Note (other than any
      such payment which is not in fact received by the Subordination Agent
      within five days of the date on which such payment is scheduled to be
      made) due from the obligor thereon or (ii) any payment of interest on the
      Certificates with funds drawn under any Liquidity Facility, which payment
      represents the installment of principal at the stated maturity of such
      installment of principal on such Equipment Note, the payment of regularly
      scheduled interest accrued on the unpaid principal amount of such
      Equipment Note, or both; provided that any payment of principal, premium,
      if any, or interest resulting from the redemption or purchase of any
      Equipment Note shall not constitute a Scheduled Payment.

            SEC: Means the Securities and Exchange Commission, as from time to
      time constituted or created under the United States Securities Exchange
      Act of 1934, as amended, or, if at any time after the execution of this
      instrument such Commission is not existing and performing the duties now
      assigned to it under the Trust Indenture Act, then the body performing
      such duties on such date.

            Securities Act: Means the United States Securities Act of 1933, as
      amended from time to time, or any successor thereto.
<PAGE>   17
                                      -12-

            Shelf Registration Statement: Means the shelf registration statement
      which may be required to be filed by the Company with the SEC pursuant to
      any Registration Rights Agreement, other than an Exchange Offer
      Registration Statement.

            Special Distribution Date: Means each date on which a Special
      Payment is to be distributed as specified in this Agreement; provided,
      however, that, if any such day shall not be a Business Day, the related
      distribution shall be made on the next succeeding Business Day without
      additional interest.

            Special Redemption Premium: Means the premium payable by the Company
      in respect of the Final Withdrawal pursuant to the Note Purchase
      Agreement.

            Special Payment: Means any payment (other than a Scheduled Payment)
      in respect of, or any proceeds of, any Equipment Note or Trust Indenture
      Estate (as defined in each Indenture) or Special Redemption Premium.

            Special Payments Account: Means the account or accounts created and
      maintained pursuant to Section 4.01(b).

            Subordination Agent: Has the meaning specified in the Intercreditor
      Agreement.

            Substitute Aircraft: Has the meaning specified in the Note Purchase
      Agreement.

            Tax: Means all license, recording, documentary, registration and
      other similar fees and all taxes, levies, imposts, duties, charges,
      assessments or withholdings of any nature whatsoever imposed by any Taxing
      Authority, together with any penalties, additions to tax, fines or
      interest thereon or additions thereto.

            Taxing Authority: Means any federal, state or local government or
      other taxing authority in the United States, any foreign government or any
      political subdivision or taxing authority thereof, any international
      taxing authority or any territory or possession of the United States or
      any taxing authority thereof.

            Transfer Date: Means the moment of execution and delivery of the
      Assignment and Assumption Agreement by each of the parties thereto.

            Transfer Date Certificates: Has the meaning specified in the
      definition of "Certificates".

            Trust: Means the trust created by this Agreement, the estate of
      which consists of the Trust Property.

            Trust Indenture Act: Means the United States Trust Indenture Act of
      1939, as amended from time to time, or any successor thereto.


            Trust Property: Means (i) the Equipment Notes held as the property
      of the Trust and, subject to the Intercreditor Agreement, all monies at
      any time paid thereon and all
<PAGE>   18
                                      -13-

      monies due and to become due thereunder, (ii) funds from time to time
      deposited in the Certificate Account and the Special Payments Account and,
      subject to the Intercreditor Agreement, any proceeds from the sale by the
      Trustee pursuant to Article VI hereof of any Equipment Note and (iii) all
      rights of the Trust and the Trustee, on behalf of the Trust, under the
      Intercreditor Agreement, the Escrow Agreement, the Note Purchase Agreement
      and the Liquidity Facilities, including, without limitation, all rights to
      receive certain payments thereunder, and all monies paid to the Trustee on
      behalf of the Trust pursuant to the Intercreditor Agreement or the
      Liquidity Facilities, provided, that rights with respect to the Deposits
      or under the Escrow Agreement will not constitute Trust Property.

            Trustee: Means Wilmington Trust Company, or its successor in
      interest, and any successor or other trustee appointed as provided herein.

            Trustee's Lien: Has the meaning specified in Section 7.17.

            Unindemnified Tax: Means (i) any Tax imposed on the net income, net
      worth or capital, any franchise Tax or similar doing business Tax of the
      Pass Through Trustee (other than any such Tax imposed as a result of the
      Company's assumption of the Equipment Notes pursuant to the purchase of an
      aircraft on an EBO Date or a Material Adverse Tax Event), (ii) any
      withholding Tax imposed by the United States (including, without
      limitation, any withholding Tax imposed by the United States which is
      imposed or increased as a result of the Pass Through Trustee failing to
      deliver to the Company any certificate or document necessary to establish
      that payments under this Agreement are exempt from withholding Tax), and
      (iii) any Avoidable Tax.

            Section 1.02. Compliance Certificates and Opinions. Upon any
application or request (except with respect to matters set forth in Article II)
by the Company, any Owner Trustee or any Loan Trustee to the Trustee to take any
action under any provision of this Agreement, the Company, such Owner Trustee or
such Loan Trustee, as the case may be, shall furnish to the Trustee (i) an
Officer's Certificate stating that, in the opinion of the signers, all
conditions precedent, if any, provided for in this Agreement relating to the
proposed action have been complied with and (ii) an Opinion of Counsel stating
that in the opinion of such counsel all such conditions precedent, if any, have
been complied with, except that in the case of any such application or request
as to which the furnishing of such documents is specifically required by any
provision of this Agreement relating to such particular application or request,
no additional certificate or opinion need be furnished.

            Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Agreement (other than a certificate
provided pursuant to Section 8.04(e)) shall include:

            (1) a statement that each individual signing such certificate or
      opinion has read such covenant or condition and the definitions in this
      Agreement relating thereto;
<PAGE>   19
                                      -14-

            (2) a brief statement as to the nature and scope of the examination
      or investigation upon which the statements or opinions contained in such
      certificate or opinion are based;

            (3) a statement that, in the opinion of each such individual, he has
      made such examination or investigation as is necessary to enable him to
      express an informed opinion as to whether or not such covenant or
      condition has been complied with; and

            (4) a statement as to whether, in the opinion of each such
      individual, such condition or covenant has been complied with.

            Section 1.03. Form of Documents Delivered to Trustee. In any case
where several matters are required to be certified by, or covered by an opinion
of, any specified Person, it is not necessary that all such matters be certified
by, or covered by the opinion of, only one such Person, or that they be so
certified or covered by only one document, but one such Person may certify or
give an opinion with respect to some matters and one or more other such Persons
as to other matters and any such Person may certify or give an opinion as to
such matters in one or several documents.

            Where any Person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Agreement or, in respect of the Certificates, this
Agreement, they may, but need not, be consolidated and form one instrument.

            Section 1.04. Directions of Certificateholders. (a) Any direction,
consent, request, demand, authorization, notice, waiver or other action provided
by this Agreement to be given or taken by Certificateholders (a "Direction") may
be embodied in and evidenced by one or more instruments of substantially similar
tenor signed by such Certificateholders in person or by an agent or proxy duly
appointed in writing; and, except as herein otherwise expressly provided, such
action shall become effective when such instrument or instruments are delivered
to the Trustee and, where it is hereby expressly required pursuant to this
Agreement, to the Company or any Loan Trustee. Proof of execution of any such
instrument or of a writing appointing any such agent or proxy shall be
sufficient for any purpose of this Agreement and conclusive in favor of the
Trustee, the Company and any Loan Trustee, if made in the manner provided in
this Section.

            (b) The fact and date of the execution by any Person of any such
instrument or writing may be proved by the certificate of any notary public or
other officer of any jurisdiction authorized to take acknowledgments of deeds or
administer oaths that the Person executing such instrument acknowledged to him
the execution thereof, or by an affidavit of a witness to such execution sworn
to before any such notary or such other officer and where such execution is by
an officer of a corporation or association or a member of a partnership, on
behalf of such corporation, association or partnership, such certificate or
affidavit shall also constitute sufficient proof of his authority. The fact and
date of the execution of any such instrument or writing, or the authority of the
Person executing the same, may also be proved in any other reasonable manner
which the Trustee deems sufficient.
<PAGE>   20
                                      -15-

            (c) In determining whether the Certificateholders of the requisite
Fractional Undivided Interests of Certificates Outstanding have given any
Direction under this Agreement, Certificates owned by the Company or any
Affiliate thereof shall be disregarded and deemed not to be Outstanding for
purposes of any such determination. In determining whether the Trustee shall be
protected in relying upon any such Direction, only Certificates which the
Trustee knows to be so owned shall be so disregarded. Notwithstanding the
foregoing, (i) if any such Person owns 100% of the Certificates Outstanding,
such Certificates shall not be so disregarded, and (ii) if any amount of
Certificates so owned by any such Person have been pledged in good faith, such
Certificates shall not be disregarded if the pledgee establishes to the
satisfaction of the Trustee the pledgee's right so to act with respect to such
Certificates and that the pledgee is not the Company or any Affiliate thereof.

            (d) For all purposes of this Agreement, all Initial Certificates
constituting Certificates and all Exchange Certificates constituting
Certificates shall vote and take all other actions of Certificateholders
together as one series of Certificates.

            (e) The Company may at its option, by delivery of an Officer's
Certificate to the Trustee, set a record date to determine the
Certificateholders entitled to give any Direction. Notwithstanding Section
316(c) of the Trust Indenture Act, such record date shall be the record date
specified in such Officer's Certificate, which shall be a date not more than 30
days prior to the first solicitation of Certificateholders in connection
therewith. If such a record date is fixed, such Direction may be given before or
after such record date, but only the Certificateholders of record at the close
of business on such record date shall be deemed to be Certificateholders for the
purposes of determining whether Certificateholders of the requisite proportion
of Outstanding Certificates have authorized or agreed or consented to such
Direction, and for that purpose the Outstanding Certificates shall be computed
as of such record date; provided that no such Direction by the
Certificateholders on such record date shall be deemed effective unless it shall
become effective pursuant to the provisions of this Agreement not later than one
year after such record date.

            (f) Any Direction by the Holder of any Certificate shall bind the
Holder of every Certificate issued upon the transfer thereof or in exchange
therefor or in lieu thereof, whether or not notation of such Direction is made
upon such Certificate.

            (g) Except as otherwise provided in Section 1.04(c), Certificates
owned by or pledged to any Person shall have an equal and proportionate benefit
under the provisions of this Agreement, without preference, priority, or
distinction as among all of the Certificates.


                                   ARTICLE II

                          ACQUISITION OF TRUST PROPERTY

            Section 2.01. Acquisition of Trust Property. The Trustee is hereby
irrevocably authorized and directed to execute and deliver the Assignment and
Assumption Agreement on the date specified in Section 11.01 of the Related Pass
Through Trust Agreement, subject only to the satisfaction of the conditions to
such execution set forth in said Section 11.01. This Agreement (except only for
the immediately preceding sentence hereof, which is effective upon
<PAGE>   21
                                      -16-

execution and delivery hereof) shall become effective upon the execution and
delivery of the Assignment and Assumption Agreement by the Trustee and the
Related Trustee, automatically and without any further signature or action on
the part of the Company and the Trustee, and shall thereupon constitute the
legal, valid and binding obligation of the parties hereto enforceable against
each of the parties hereto in accordance with its terms. Upon such execution and
delivery of the Assignment and Assumption Agreement, the Related Trust shall be
terminated, the Certificateholders shall receive beneficial interests in the
Trust in exchange for their interests in the Related Trust equal to their
respective beneficial interests in the Related Trust and the "Outstanding" (as
defined in the Related Pass Through Trust Agreement) pass through certificates
representing fractional undivided interests in the Related Trust shall be deemed
for all purposes of this Agreement and the Related Pass Through Trust Agreement,
without further signature or action of any party or Certificateholder, to be
Certificates representing the same Fractional Undivided Interests in the Trust
and the Trust Property. By acceptance of its Certificate, each Certificateholder
consents to and ratifies such assignment, transfer and delivery of the trust
property of the Related Trust to the Trustee upon the execution and delivery of
the Assignment and Assumption Agreement.

            Section 2.02. Acceptance by Trustee. The Trustee, upon the execution
and delivery of the Assignment and Assumption Agreement, acknowledges its
acceptance of all right, title and interest in and to the Trust Property and
declares that the Trustee holds and will hold such right, title and interest for
the benefit of all then present and future Certificateholders, upon the trusts
herein set forth. Subject to Section 7.14, the Trustee shall take all actions
reasonably necessary to maintain the registration of all such Equipment Notes in
the name of the Subordination Agent. By the acceptance of each Certificate
issued to it under the Related Pass Through Trust Agreement and deemed issued
under this Agreement, each Holder of any such Certificate as grantor of the
Trust thereby joins in the creation and declaration of the Trust.

            Section 2.03. Limitation of Powers. The Trust is constituted solely
for the purpose of making the investment in the Equipment Notes, and, except as
set forth herein, the Trustee shall not be authorized or empowered to acquire
any other investments or engage in any other activities and, in particular, the
Trustee shall not be authorized or empowered to do anything that would cause
such Trust to fail to qualify as a "grantor trust" for federal income tax
purposes (including as subject to this restriction, acquiring any Aircraft (as
defined in the respective Indentures) by bidding such Equipment Notes or
otherwise, or taking any action with respect to any such Aircraft once
acquired).


                                   ARTICLE III

                                THE CERTIFICATES

            Section 3.01. Title, Form, Denomination and Execution of
Certificates. (a) The Initial Certificates constituting Certificates shall be
known as the "7.12% Initial Pass Through Certificates, Series 1998-1B-S" and the
Exchange Certificates constituting Certificates shall be known as the "7.12%
Exchange Pass Through Certificates, Series 1998-1B-S", in each case, of the
Trust. Each Certificate will represent a fractional undivided interest in the
Trust and shall be substantially in the form set forth as Exhibit A to the
Related Pass Through Trust Agreement, with such appropriate insertions,
omissions, substitutions and other variations as are required or
<PAGE>   22
                                      -17-

permitted by the Related Pass Through Trust Agreement or this Agreement, as the
case may be, or as the Trustee may deem appropriate to reflect the fact that the
Certificates are being issued hereunder as opposed to the Related Pass Through
Trust Agreement, and may have such letters, numbers or other marks of
identification and such legends or endorsements placed thereon as may be
required to comply with the rules of any securities exchange or as may,
consistently herewith, be determined by the Trustee or the officers executing
such Certificates, as evidenced by the Trustee's or officer's execution of the
Certificates (provided that such letters, numbers or other marks of
identification and such legends or endorsements are in a form acceptable to the
Company). At the Escrow Agent's request under the Escrow Agreement, the Trustee
shall affix the corresponding Escrow Receipt to any Certificate issued
hereunder. Any transfer or exchange of any Certificate shall also effect a
transfer or exchange of the related Escrow Receipt. Prior to the Final
Withdrawal Date, no transfer or exchange of any Certificate shall be permitted
unless the corresponding Escrow Receipt is attached thereto and also is so
transferred or exchanged. By acceptance of any Certificate to which an Escrow
Receipt is attached, each Holder of such a Certificate acknowledges and accepts
the restrictions on transfer of the Escrow Receipt set forth herein and in the
Escrow Agreement.

            (b) The Initial Certificates shall be issued only in fully
registered form without coupons and only in denominations of $100,000 or
integral multiples of $1,000 in excess thereof, except that one Certificate may
be issued in a different denomination. The Exchange Certificates will be issued
in denominations of $1,000 or integral multiples thereof, except that one
Certificate may be issued in a different denomination. Each Certificate shall be
dated the date of its authentication. The aggregate Fractional Undivided
Interest of Certificates shall not at any time exceed $41,154,000.

            (c) The Initial Certificates offered and sold in reliance on Rule
144A shall be in the form of one or more Global Certificates substantially in
the form of Exhibit A to the Related Pass Through Trust Agreement with such
applicable legends as are provided for in Section 3.02 (each a "Restricted
Global Certificate"). Such Restricted Global Certificates shall be in registered
form and be registered in the name of DTC and deposited with the Trustee, at its
Corporate Trust Office, as custodian for DTC. The aggregate principal amount of
any Restricted Global Certificate may from time to time be increased or
decreased by adjustments made on the records of the Trustee, as custodian for
DTC for such Restricted Global Certificate, as provided in Section 3.06 hereof,
which adjustments shall be conclusive as to the aggregate principal amount of
any such Global Certificate.

            (d) The Initial Certificates offered and sold outside the United
States in reliance on Regulation S shall be in the form of one or more global
Certificates substantially in the form of Exhibit A to the Related Pass Through
Trust Agreement (each a "Regulation S Global Certificate"). Such Regulation S
Global Certificates shall be in registered form and be registered in the name of
DTC and deposited with the Trustee, at its Corporate Trust Office, as custodian
for DTC, for credit initially and during the Restricted Period (hereinafter
defined) to the respective accounts of beneficial owners of such Certificates
(or to such other accounts as they may direct) at Morgan Guaranty Trust Company
of New York, Brussels office, as operator of Euroclear or Cedel. As used herein,
the term "Restricted Period", with respect to the Regulation S Global
Certificates offered and sold in reliance on Regulation S, means the period of
40 consecutive days beginning on and including the later of (i) the day on which
the
<PAGE>   23
                                      -18-

"Certificates" (as defined in the Related Pass Through Trust Agreement are first
offered to persons other than distributors (as defined in Regulation S) in
reliance on Regulation S and (ii) the date of the closing of the offering under
the Certificate Purchase Agreement. The aggregate principal amount of any
Regulation S Global Certificate may from time to time be increased or decreased
by adjustments made on the records of the Trustee, as custodian for DTC for such
Global Certificate, as provided in Section 3.06 hereof, which adjustments shall
be conclusive as to the aggregate principal amount of any such Global
Certificate. The Restricted Global Certificate and Regulation S Global
Certificate are sometimes collectively referred to herein as the "Global
Certificates".

            (e) Initial Certificates offered and sold to any Institutional
Accredited Investor which is not a QIB in a transaction exempt from registration
under the Securities Act (and other than as described in Section 3.01(d)) shall
be substantially in the form of Exhibit A to the Related Pass Through Trust
Agreement in definitive, fully registered form without interest coupons with
such applicable legends as are provided for in Section 3.02 (the "Restricted
Definitive Certificates"). Such Certificates issued pursuant to Section 3.05(b)
in exchange for interests in a Regulation S Global Certificate shall be issued
in definitive, fully registered form without interest coupons (the "Regulation S
Definitive Certificates"). The Restricted Definitive Certificates and the
Regulation S Definitive Certificates are sometimes collectively referred to
herein as the "Definitive Certificates".

            (f) The Exchange Certificates exchanged for Initial Certificates
under the Related Trust shall be in the form of one or more global Certificates
substantially in the form of Exhibit A thereto (each, a "Global Exchange
Certificate"). Exchange Certificates issued under this Trust (each, also a
"Global Exchange Certificate") shall be in the form of one or more global
certificates substantially in the form of Exhibit A to the Related Pass Through
Trust Agreement except that (i) the Restricted Legend (hereinafter defined)
shall be omitted and (ii) such Exchange Certificates shall contain such
appropriate insertions, omissions, substitutions and other variations from the
form set forth in Exhibit A to the Related Pass Through Trust Agreement relating
to the nature of the Exchange Certificates or to reflect the fact that the
Certificates are being issued hereunder as opposed to the Related Pass Through
Trust Agreement, as the Responsible Officer of the Trustee executing such
Exchange Certificates on behalf of the Trust may determine, as evidenced by such
officer's execution on behalf of the Trust of such Exchange Certificates. Such
Global Exchange Certificates shall be in registered form and be registered in
the name of DTC and deposited with the Trustee, at its Corporate Trust Office,
as custodian for DTC. The aggregate principal amount of any Global Exchange
Certificate may from time to time be increased or decreased by adjustments made
on the records of the Trustee, as custodian for DTC for such Global Exchange
Certificate, which adjustments shall be conclusive as to the aggregate principal
amount of any such Global Exchange Certificate. Subject to clause (i) and (ii)
of the second sentence of this Section 3.01(f), the terms hereof applicable to
Restricted Global Certificates and/or Global Certificates shall apply to the
Global Exchange Certificates, mutatis mutandis.

            (g) The Definitive Certificates shall be in registered form and
shall be typed, printed, lithographed or engraved or produced by any combination
of these methods or may be produced in any other manner, all as determined by
the officers executing such Certificates, as evidenced by their execution of
such Certificates.
<PAGE>   24
                                      -19-

            Section 3.02. Restrictive Legends. All Initial Certificates issued
for resale pursuant to Rule 144A or offered and sold to any Institutional
Accredited Investor which is not a QIB (including any Global Certificate issued
upon registration of transfer, in exchange for or in lieu of such Certificates)
shall be "Restricted Certificates" and shall bear a legend to the following
effect (the "Restricted Legend") unless the Company and the Trustee determine
otherwise consistent with applicable law:

            THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE U.S. SECURITIES
      ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND ACCORDINGLY, MAY NOT
      BE OFFERED OR SOLD WITHIN THE UNITED STATES OR TO, OR FOR THE ACCOUNT OR
      BENEFIT OF, ANY PERSONS EXCEPT AS SET FORTH IN THE FOLLOWING SENTENCE. BY
      ITS ACQUISITION HEREOF, THE HOLDER (1) REPRESENTS THAT (A) IT IS A
      "QUALIFIED INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A UNDER THE
      SECURITIES ACT), (B) IT IS AN INSTITUTIONAL "ACCREDITED INVESTOR" (AS
      DEFINED IN RULE 501(a)(1), (2), (3) OR (7) OF REGULATION D UNDER THE
      SECURITIES ACT) (AN "INSTITUTIONAL ACCREDITED INVESTOR") OR (C) IT IS NOT
      A U.S. PERSON AND IS ACQUIRING THIS CERTIFICATE IN AN OFFSHORE TRANSACTION
      IN COMPLIANCE WITH REGULATION S UNDER THE SECURITIES ACT; (2) AGREES THAT
      IT WILL NOT WITHIN TWO YEARS AFTER THE LATER OF THE ORIGINAL ISSUANCE OF
      THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS CERTIFICATE WAS HELD BY
      AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY AFFILIATE OF ANY OF SUCH
      PERSONS RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE EXCEPT (A) TO
      AMERICA WEST AIRLINES, INC., (B) TO A QUALIFIED INSTITUTIONAL BUYER IN
      COMPLIANCE WITH RULE 144A UNDER THE SECURITIES ACT, (C) OUTSIDE THE UNITED
      STATES IN AN OFFSHORE TRANSACTION IN COMPLIANCE WITH RULE 904 UNDER THE
      SECURITIES ACT, (D) PURSUANT TO THE EXEMPTION FROM REGISTRATION PROVIDED
      BY RULE 144 UNDER THE SECURITIES ACT (IF AVAILABLE) OR (E) PURSUANT TO AN
      EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT; AND (3) AGREES
      THAT IF IT SHOULD RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE IT WILL
      DELIVER TO EACH PERSON TO WHOM THIS CERTIFICATE IS TRANSFERRED A NOTICE
      SUBSTANTIALLY TO THE EFFECT OF THIS LEGEND. IN CONNECTION WITH ANY
      TRANSFER OF THIS CERTIFICATE WITHIN TWO YEARS AFTER THE LATER OF THE
      ORIGINAL ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS
      CERTIFICATE WAS HELD BY AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY
      AFFILIATE OF ANY OF SUCH PERSONS, THE HOLDER MUST CHECK THE APPROPRIATE
      BOX SET FORTH ON THE REVERSE HEREOF RELATING TO THE MANNER OF SUCH
      TRANSFER AND SUBMIT THIS CERTIFICATE TO THE TRUSTEE. AS USED HEREIN, THE
      TERMS "OFFSHORE TRANSACTION", "UNITED STATES" AND "U.S. PERSON" HAVE THE
      MEANINGS GIVEN TO THEM BY REGULATION S UNDER THE SECURITIES ACT. THE PASS
      THROUGH TRUST AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO
      REFUSE TO REGISTER ANY 
<PAGE>   25
                                      -20-

      TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE FOREGOING RESTRICTIONS.

            Each Global Certificate shall bear the following legend on the face
thereof:

            UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE
      OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE
      TRUSTEE OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT,
      AND ANY CERTIFICATE ISSUED IN EXCHANGE FOR THIS CERTIFICATE IS REGISTERED
      IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN
      AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT HEREON IS MADE TO CEDE &
      CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED
      REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE
      OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED
      OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

            TRANSFERS OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO TRANSFERS
      IN WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A SUCCESSOR THEREOF OR
      SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL
      CERTIFICATE SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE
      RESTRICTIONS SET FORTH IN SECTIONS 3.05 AND 3.06 OF THE PASS THROUGH TRUST
      AGREEMENT REFERRED TO HEREIN.

            Section 3.03. Authentication of Certificates. (a) No Certificate
shall be entitled to any benefit under this Agreement or be valid or obligatory
for any purpose, unless there appears on such Certificate a certificate of
authentication substantially in the form provided for herein executed by the
Trustee by the manual signature of one of its authorized signatories, and such
certificate upon any Certificate shall be conclusive evidence, and the only
evidence, that such Certificate has been duly authenticated and delivered
hereunder.

            (b) Certificates bearing the manual or facsimile signature of an
individual who was, at the time when such signature was affixed, authorized to
sign on behalf of the Trustee shall be valid and binding obligations of the
Trust notwithstanding that such individual has ceased to be so authorized prior
to the authentication and delivery of such Certificates or did not hold such
office on the date of such Certificates.

            Section 3.04. Transfer and Exchange. The Trustee shall cause to be
kept at the office or agency to be maintained by it in accordance with the
provisions of Section 7.12 a register (the "Register") of the Certificates in
which, subject to such reasonable regulations as it may prescribe, the Trustee
shall provide for the registration of such Certificates and of transfers and
exchanges of such Certificates as herein provided. The Trustee shall initially
be the registrar (the "Registrar") for the purpose of registering such
Certificates and transfers and exchanges of such Certificates as herein
provided. The Company, upon notice to the Trustee, may change the Registrar at
any time.
<PAGE>   26
                                      -21-

            All Certificates issued upon any registration of transfer or
exchange of Certificates shall be valid obligations of the Trust, evidencing the
same interest therein, and entitled to the same benefits under this Agreement,
as the Certificates surrendered upon such registration of transfer or exchange.

            A Certificateholder may transfer a Certificate, or request that a
Certificate be exchanged for Certificates in an aggregate Fractional Undivided
Interest equal to the Fractional Undivided Interest of such Certificate
surrendered for exchange of other authorized denominations, by surrender of such
Certificate to the Trustee with the form of transfer notice thereon duly
completed and executed, and otherwise complying with the terms of this
Agreement, including providing evidence of compliance with any restrictions on
transfer, in form satisfactory to the Trustee and the Registrar; provided that
no exchanges of Initial Certificates for Exchange Certificates shall occur until
an Exchange Offer Registration Statement shall have been declared effective by
the SEC (notice of which shall be provided to the Trustee by the Company). No
such transfer shall be effected until, and such transferee shall succeed to the
rights of a Certificateholder only upon, final acceptance and registration of
the transfer by the Registrar in the Register. Prior to the registration of any
transfer by a Certificateholder as provided herein, the Trustee shall treat the
person in whose name the Certificate is registered as the owner thereof for all
purposes, and the Trustee shall not be affected by notice to the contrary.
Furthermore, DTC shall, by acceptance of a Global Certificate, agree that
transfers of beneficial interests in such Global Certificate may be effected
only through a book-entry system maintained by DTC (or its agent), and that
ownership of a beneficial interest in the Certificate shall be required to be
reflected in book-entry. When Certificates are presented to the Registrar with a
request to register the transfer thereof or to exchange them for other
authorized denominations of a Certificate in a Fractional Undivided Interest
equal to the aggregate Fractional Undivided Interest of Certificates surrendered
for exchange, the Registrar shall register the transfer or make the exchange as
requested if its requirements for such transactions are met.

            To permit registrations of transfers and exchanges in accordance
with the terms, conditions and restrictions hereof, the Trustee shall execute
and authenticate Certificates at the Registrar's request. No service charge
shall be made to a Certificateholder for any registration of transfer or
exchange of Certificates, but the Trustee shall require payment of a sum
sufficient to cover any tax or governmental charge that may be imposed in
connection with any transfer or exchange of Certificates. All Certificates
surrendered for registration of transfer or exchange shall be canceled and
subsequently destroyed by the Trustee.

            Section 3.05. Book-Entry Provisions for Restricted Global
Certificates and Regulation S Global Certificates. (a) Members of, or
participants in, DTC ("Agent Members") shall have no rights under this Agreement
with respect to any Global Certificate held on their behalf by DTC, or the
Trustee as its custodian, and DTC may be treated by the Trustee and any agent of
the Trustee as the absolute owner of such Global Certificate for all purposes
whatsoever. Notwithstanding the foregoing, nothing herein shall prevent the
Trustee or any agent of the Trustee from giving effect to any written
certification, proxy or other authorization furnished by DTC or shall impair, as
between DTC and its Agent Members, the operation of customary practices
governing the exercise of the rights of a holder of any Certificate. Upon the
issuance of any Global Certificate, the Registrar or its duly appointed agent
shall record DTC as the registered holder of such Global Certificate.
<PAGE>   27
                                      -22-

            (b) Transfers of any Global Certificate shall be limited to
transfers of such Restricted Global Certificate or Regulation S Global
Certificate in whole, but not in part, to DTC. Beneficial interests in the
Restricted Global Certificate and any Regulation S Global Certificate may be
transferred in accordance with the rules and procedures of DTC and the
provisions of Section 3.06. Beneficial interests in a Restricted Global
Certificate or a Regulation S Global Certificate shall be (or, under the Related
Pass Through Trust Agreement, may have been) delivered to all beneficial owners
thereof in the form of Restricted Definitive Certificates or Regulation S
Definitive Certificates, as the case may be, if (i) DTC notifies the Trustee
that it is unwilling or unable to continue as depositary for such Restricted
Global Certificate or Regulation S Global Certificate, as the case may be, and a
successor depositary is not appointed by the Trustee within 90 days of such
notice, and (ii) after the occurrence and during the continuance of an Event of
Default, owners of beneficial interests in a Global Certificate with Fractional
Undivided Interests aggregating not less than a majority in interest in the
Trust advise the Trustee, the Company and DTC through Agent Members in writing
that the continuation of a book-entry system through DTC or its successor is no
longer in their best interests.

            (c) Any beneficial interest in one of the Global Certificates that
is transferred to a Person who takes delivery in the form of an interest in
another Global Certificate will, upon such transfer, cease to be an interest in
such Global Certificate and become an interest in the other Global Certificate
and, accordingly, will thereafter be subject to all transfer restrictions, if
any, and other procedures applicable to beneficial interests in such other
Global Certificate for as long as it remains such an interest.

            (d) In connection with the transfer of an entire Restricted Global
Certificate or an entire Regulation S Global Certificate to the beneficial
owners thereof pursuant to paragraph (b) of this Section 3.05, such Restricted
Global Certificate or Regulation S Global Certificate, as the case may be, shall
be deemed to be surrendered to the Trustee for cancellation, and the Trustee
shall execute, authenticate and deliver, to each beneficial owner identified by
DTC in exchange for its beneficial interest in such Restricted Global
Certificate or Regulation S Global Certificate, as the case may be, an equal
aggregate principal amount of Restricted Definitive Certificates or Regulation S
Definitive Certificates, as the case may be, of authorized denominations. None
of the Company, the Registrar, the Paying Agent nor the Trustee shall be liable
for any delay in delivery of such instructions and may conclusively rely on, and
shall be protected in relying on, such registration instructions. Upon the
issuance of Definitive Certificates, the Trustee shall recognize the Person in
whose name the Definitive Certificates are registered in the Register as
Certificateholders hereunder. Neither the Company nor the Trustee shall be
liable if the Trustee or the Company is unable to locate a qualified successor
clearing agency.

            (e) Any Definitive Certificate delivered in exchange for an interest
in the Restricted Global Certificate pursuant to paragraph (b) of this Section
3.05 shall, except as otherwise provided by paragraph (e) of Section 3.06, bear
the Restricted Legend.

            (f) Prior to the expiration of the Restricted Period, any Regulation
S Definitive Certificate delivered in exchange for an interest in a Regulation S
Global Certificate pursuant to paragraph (b) of this Section shall bear the
Restricted Legend.
<PAGE>   28
                                      -23-

            (g) The registered holder of any Restricted Global Certificate or
Regulation S Global Certificate may grant proxies and otherwise authorize any
Person, including Agent Members and Persons that may hold interests through
Agent Members, to take any action which a Holder is entitled to take under this
Agreement or the Certificates.

            Section 3.06. Special Transfer Provisions Unless and until (i) an
Initial Certificate is sold under an effective Shelf Registration Statement, or
(ii) an Initial Certificate is exchanged for an Exchange Certificate pursuant to
an effective Exchange Offer Registration Statement, in each case pursuant to the
terms of the Registration Rights Agreement, the following provisions shall apply
to such Initial Certificates:

            (a) Transfers to Non-QIB Institutional Accredited Investors. The
      following provisions shall apply with respect to the registration of any
      proposed transfer of a Certificate to any Institutional Accredited
      Investor which is neither a QIB nor a Non-U.S. Person:

                         (i) The Registrar shall register the transfer of any
            Certificate, whether or not bearing the Restricted Legend, only if
            (x) the requested transfer is at least two years after the later of
            the original issue date of the Certificates and the last date on
            which such Certificate was held by the Company, the Trustee or any
            affiliate of any of such Persons or (y) the proposed transferor is
            an Initial Purchaser who is transferring Certificates purchased
            under the Certificates Purchase Agreement and the proposed
            transferee has delivered to the Registrar a letter substantially in
            the form of Exhibit B hereto and the aggregate principal amount of
            the Certificates being transferred is at least $100,000. Except as
            provided in the foregoing clause (y), the Registrar shall not
            register the transfer of any Certificate to any Institutional
            Accredited Investor which is neither a QIB nor a Non-U.S. Person.

                         (ii) If the proposed transferor is an Agent Member
            holding a beneficial interest in a Restricted Global Certificate,
            upon receipt by the Registrar of (x) the documents, if any, required
            by paragraph (i) and (y) instructions given in accordance with DTC's
            and the Registrar's procedures, the Registrar shall reflect on its
            books and records the date of the transfer and a decrease in the
            principal amount of such Restricted Global Certificate in an amount
            equal to the principal amount of the beneficial interest in such
            Restricted Global Certificate to be transferred, and the Trustee
            shall execute, authenticate and deliver to the transferor or at its
            direction, one or more Restricted Definitive Certificates of like
            tenor and amount.

            (b) Transfers to QIBs. The following provisions shall apply with
      respect to the registration of any proposed transfer of an Initial
      Certificate to a QIB (excluding Non-U.S. Persons):

                         (i) If the Certificate to be transferred consists of
            Restricted Definitive Certificates, or of an interest in any
            Regulation S Global Certificate during the Restricted Period, the
            Registrar shall register the transfer if such
<PAGE>   29
                                      -24-

            transfer is being made by a proposed transferor who has checked the
            box provided for on the form of Initial Certificate stating, or has
            otherwise advised the Trustee and the Registrar in writing, that the
            sale has been made in compliance with the provisions of Rule 144A to
            a transferee who has signed the certification provided for on the
            form of Initial Certificate stating, or has otherwise advised the
            Trustee and the Registrar in writing, that it is purchasing the
            Initial Certificate for its own account or an account with respect
            to which it exercises sole investment discretion and that it, or the
            Person on whose behalf it is acting with respect to any such
            account, is a QIB within the meaning of Rule 144A, and is aware that
            the sale to it is being made in reliance on Rule 144A and
            acknowledges that it has received such information regarding the
            Trust and/or the Company as it has requested pursuant to Rule 144A
            or has determined not to request such information and that it is
            aware that the transferor is relying upon its foregoing
            representations in order to claim the exemption from registration
            provided by Rule 144A.

                         (ii) Upon receipt by the Registrar of the documents
            required by clause (i) above and instructions given in accordance
            with DTC's and the Registrar's procedures therefor, the Registrar
            shall reflect on its books and records the date of such transfer and
            an increase in the principal amount of a Restricted Global
            Certificate in an amount equal to the principal amount of the
            Restricted Definitive Certificates or interests in such Regulation S
            Global Certificate, as the case may be, being transferred, and the
            Trustee shall cancel such Definitive Certificates or decrease the
            amount of such Regulation S Global Certificate so transferred.

            (c) Transfers of Interests in the Regulation S Global Certificate or
      Regulation S Definitive Certificates. After the expiration of the
      Restricted Period, the Registrar shall register any transfer of interests
      in any Regulation S Global Certificate or Regulation S Definitive
      Certificates without requiring any additional certification. Until the
      expiration of the Restricted Period, interests in the Regulation S Global
      Certificate may only be held through Agent Members acting for and on
      behalf of Euroclear and Cedel.

            (d)  Transfers to Non-U.S. Persons at Any Time.  The following
      provisions shall apply with respect to any registration of any transfer
      of an Initial Certificate to a Non-U.S. Person:

                         (i) Prior to the expiration of the Restricted Period,
            the Registrar shall register any proposed transfer of an Initial
            Certificate to a Non-U.S.Person upon receipt of a certificate
            substantially in the form set forth as Exhibit A hereto from the
            proposed transferor.

                         (ii) After the expiration of the Restricted Period, the
            Registrar shall register any proposed transfer to any Non-U.S.
            Person if the Certificate to be transferred is a Restricted
            Definitive Certificate or an interest in a Restricted Global
            Certificate, upon receipt of a certificate substantially in the form
            of Exhibit A from the proposed transferor. The Registrar shall
            promptly send a copy of such certificate to the Company.
<PAGE>   30
                                      -25-

                         (iii) Upon receipt by the Registrar of (x) the
            documents, if any, required by clause (ii) and (y) instructions in
            accordance with DTC's and the Registrar's procedures, the Registrar
            shall reflect on its books and records the date of such transfer and
            a decrease in the principal amount of such Restricted Global
            Certificate in an amount equal to the principal amount of the
            beneficial interest in such Restricted Global Certificate to be
            transferred, and, upon receipt by the Registrar of instructions
            given in accordance with DTC's and the Registrar's procedures, the
            Registrar shall reflect on its books and records the date and an
            increase in the principal amount of the Regulation S Global
            Certificate in an amount equal to the principal amount of the
            Restricted Definitive Certificate or the Restricted Global
            Certificate, as the case may be, to be transferred, and the Trustee
            shall cancel the Definitive Certificate, if any, so transferred or
            decrease the amount of such Restricted Global Certificate.

            (e) Restricted Legend. Upon the transfer, exchange or replacement of
      Certificates not bearing the Restricted Legend, the Registrar shall
      deliver Certificates that do not bear the Restricted Legend. Upon the
      transfer, exchange or replacement of Certificates bearing the Restricted
      Legend, the Registrar shall deliver only Certificates that bear the
      Restricted Legend unless either (i) the circumstances contemplated by
      paragraph (d)(ii) of this Section 3.06 exist or (ii) there is delivered to
      the Registrar an Opinion of Counsel to the effect that neither such legend
      nor the related restrictions on transfer are required in order to maintain
      compliance with the provisions of the Securities Act.

            (f) General. By acceptance of any Certificate bearing the Restricted
      Legend, each Holder of such a Certificate acknowledges the restrictions on
      transfer of such Certificate set forth in this Agreement and agrees that
      it will transfer such Certificate only as provided in this Agreement. The
      Registrar shall not register a transfer of any Certificate unless such
      transfer complies with the restrictions on transfer, if any, of such
      Certificate set forth in this Agreement. In connection with any transfer
      of Certificates, each Certificateholder agrees by its acceptance of the
      Certificates to furnish the Registrar or the Trustee such certifications,
      legal opinions or other information as either of them may reasonably
      require to confirm that such transfer is being made pursuant to an
      exemption from, or a transaction not subject to, the registration
      requirements of the Securities Act and in accordance with the terms and
      provisions of this Article III; provided that the Registrar shall not be
      required to determine the sufficiency of any such certifications, legal
      opinions or other information.

            Until such time as no Certificates remain Outstanding, the Registrar
shall retain copies of all letters, notices and other written communications
received pursuant to Section 3.05 or this Section 3.06. The Trustee, if not the
Registrar at such time, shall have the right to inspect and make copies of all
such letters, notices or other written communications at any reasonable time
upon the giving of reasonable written notice to the Registrar.

            Section 3.07. Mutilated, Destroyed, Lost or Stolen Certificates. If
(a) any mutilated Certificate is surrendered to the Registrar or the Registrar
receives evidence to its satisfaction of the destruction, loss or theft of any
Certificate and (b) there is delivered to the
<PAGE>   31
                                      -26-

Registrar and the Trustee such security, indemnity or bond, as may be required
by them to save each of them harmless, then, in the absence of notice to the
Registrar or the Trustee that such destroyed, lost or stolen Certificate has
been acquired by a protected purchaser, and provided that the requirements of
Section 8-405 of the Uniform Commercial Code in effect in any applicable
jurisdiction are met, the Trustee shall execute, authenticate and deliver, in
exchange for or in lieu of any such mutilated, destroyed, lost or stolen
Certificate, a new Certificate or Certificates, in authorized denominations and
of like Fractional Undivided Interest and bearing a number not contemporaneously
outstanding.

            In connection with the issuance of any new Certificate under this
Section 3.07, the Trustee may require the payment of a sum sufficient to cover
any tax or other governmental charge that may be imposed in relation thereto and
any other expenses (including the fees and expenses of the Trustee and the
Registrar) connected therewith.

            Any duplicate Certificate issued pursuant to this Section 3.07 shall
constitute conclusive evidence of the appropriate Fractional Undivided Interest
in the Trust, as if originally issued, whether or not the lost, stolen or
destroyed Certificate shall be found at any time.

            The provisions of this Section are exclusive and shall preclude (to
the extent lawful) all other rights and remedies with respect to the replacement
or payment of mutilated, destroyed, lost or stolen Certificates.

            Section 3.08. Persons Deemed Owners. Prior to due presentment of a
Certificate for registration of transfer, the Trustee, the Registrar and any
Paying Agent may treat the Person in whose name any Certificate is registered
(as of the day of determination) as the owner of such Certificate for the
purpose of receiving distributions pursuant to Article IV and for all other
purposes whatsoever, and none of the Trustee, the Registrar or any Paying Agent
shall be affected by any notice to the contrary.

            Section 3.09. Cancellation. All Certificates surrendered for payment
or transfer or exchange shall, if surrendered to the Trustee or any agent of the
Trustee other than the Registrar, be delivered to the Registrar for cancellation
and shall promptly be canceled by it. No Certificates shall be authenticated in
lieu of or in exchange for any Certificates canceled as provided in this
Section, except as expressly permitted by this Agreement. All canceled
Certificates held by the Registrar shall be destroyed and a certification of
their destruction delivered to the Trustee.

            Section 3.10. Temporary Certificates. Until definitive Certificates
are ready for delivery, the Trustee shall authenticate temporary Certificates.
Temporary Certificates shall be substantially in the form of definitive
Certificates but may have insertions, substitutions, omissions and other
variations determined to be appropriate by the officers executing the temporary
Certificates, as evidenced by their execution of such temporary Certificates. If
temporary Certificates are issued, the Trustee will cause definitive
Certificates to be prepared without unreasonable delay. After the preparation of
definitive Certificates, the temporary Certificates shall be exchangeable for
definitive Certificates upon surrender of the temporary Certificates at the
office or agency of the Trustee designated for such purpose pursuant to Section
7.12, without charge to the Certificateholder. Upon surrender for cancellation
of any one
<PAGE>   32
                                      -27-

or more temporary Certificates, the Trustee shall execute, authenticate and
deliver in exchange therefor a like face amount of definitive Certificates of
authorized denominations. Until so exchanged, the temporary Certificates shall
be entitled to the same benefits under this Agreement as definitive
Certificates.

            Section 3.11. Limitation of Liability for Payments. All payments and
distributions made to Certificateholders in respect of the Certificates shall be
made only from the Trust Property and only to the extent that the Trustee shall
have sufficient income or proceeds from the Trust Property to make such payments
in accordance with the terms of Article IV of this Agreement. Each
Certificateholder, by its acceptance of a Certificate, agrees that it will look
solely to the income and proceeds from the Trust Property for any payment or
distribution due to such Certificateholder pursuant to the terms of this
Agreement and that it will not have any recourse to the Company, the Trustee,
the Loan Trustees, the Liquidity Providers, the Owner Trustees or the Owner
Participants, except as otherwise expressly provided herein or in the
Intercreditor Agreement.

            The Company is a party to this Agreement solely for purposes of
meeting the requirements of the Trust Indenture Act, and therefore shall not
have any right, obligation or liability hereunder (except as otherwise expressly
provided herein).

            Section 3.12 ERISA Restrictive Legend. All Certificates issued
pursuant to this Agreement shall bear a legend to the following effect (the
"ERISA Legend") unless the Company and the Trustee determine otherwise
consistent with applicable law:

            "BY ITS ACQUISITION HEREOF, THE HOLDER REPRESENTS THAT (A) NO PLAN
ASSETS HAVE BEEN USED TO PURCHASE THIS CERTIFICATE OR AN INTEREST HEREIN OR (B)
THE PURCHASE AND HOLDING OF THIS CERTIFICATE OR AN INTEREST HEREIN IS EXEMPT
FROM THE PROHIBITED TRANSACTION RESTRICTIONS OF ERISA AND THE CODE PURSUANT TO
ONE OR MORE PROHIBITED TRANSACTION STATUTORY OR ADMINISTRATIVE EXEMPTIONS. THE
PASS THROUGH TRUST AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO
REFUSE TO REGISTER ANY TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE
FOREGOING RESTRICTIONS."

            By acceptance of any Certificate bearing the ERISA Legend, each
Holder of such a Certificate acknowledges the restrictions on transfer of such
Certificate set forth in this Agreement and agrees that it will transfer such
Certificate only as provided in this Agreement. The Trustee shall not register a
transfer of any Certificate unless such transfer complies with the restrictions
on transfer, if any, of such Certificate set forth in such legend.


                                   ARTICLE IV

                          DISTRIBUTIONS; STATEMENTS TO
                               CERTIFICATEHOLDERS

            Section 4.01. Certificate Account and Special Payments Account. (a)
The Trustee shall maintain on behalf of the Certificateholders a Certificate
Account as one or more
<PAGE>   33
                                      -28-

non-interest-bearing accounts. The Trustee shall hold the Certificate Account in
trust for the benefit of the Certificateholders, and shall make or permit
withdrawals therefrom only as provided in this Agreement. On each day when a
Scheduled Payment is made to the Trustee under the Intercreditor Agreement, the
Trustee upon receipt thereof shall immediately deposit the aggregate amount of
such Scheduled Payment in the Certificate Account.

            (b) The Trustee shall maintain on behalf of the Certificateholders
a Special Payments Account as one or more accounts, which shall be non-interest
bearing except as provided in Section 4.04. The Trustee shall hold the Special
Payments Account in trust for the benefit of the Certificateholders and shall
make or permit withdrawals therefrom only as provided in this Agreement. On each
day when one or more Special Payments are made to the Trustee under the
Intercreditor Agreement and upon the payment of the Special Redemption Premium
to the Trustee under the Note Purchase Agreement, the Trustee, upon receipt
thereof, shall immediately deposit the aggregate amount of such Special Payments
in the Special Payments Account.

            (c) The Trustee shall cause the Subordination Agent to present to
the related Loan Trustee of each Equipment Note such Equipment Note on the date
of its stated final maturity or, in the case of any Equipment Note which is to
be redeemed in whole pursuant to the related Indenture, on the applicable
redemption date under such Indenture.

            Section 4.02. Distributions from Certificate Account and Special
Payments Account. (a) On each Regular Distribution Date or as soon thereafter as
the Trustee has confirmed receipt of the payment of all or any part of the
Scheduled Payments due on such date, the Trustee shall distribute out of the
Certificate Account the entire amount deposited therein pursuant to Section
4.01(a). There shall be so distributed to each Certificateholder of record on
the Record Date with respect to such Regular Distribution Date (other than as
provided in Section 11.01 concerning the final distribution) by check mailed to
such Certificateholder, at the address appearing in the Register, such
Certificateholder's pro rata share (based on the Fractional Undivided Interest
in the Trust held by such Certificateholder) of the total amount in the
Certificate Account, except that, with respect to Certificates registered on the
Record Date in the name of DTC, such distribution shall be made by wire transfer
in immediately available funds to the account designated by DTC.

            (b) On each Special Distribution Date with respect to any Special
Payment or as soon thereafter as the Trustee has confirmed receipt of any
Special Payments due on the Equipment Notes held in the related Trust or
realized upon the sale of such Equipment Notes or receipt of the Special
Redemption Premium, the Trustee shall distribute out of the Special Payments
Account the entire amount of such Special Payment deposited therein pursuant to
Section 4.01(b). There shall be so distributed to each Certificateholder of
record on the Record Date with respect to such Special Distribution Date (other
than as provided in Section 11.01 concerning the final distribution) by check
mailed to such Certificateholder, at the address appearing in the Register, such
Certificateholder's pro rata share (based on the Fractional Undivided Interest
in the Trust held by such Certificateholder) of the total amount in the Special
Payments Account on account of such Special Payment, except that, with respect
to Certificates registered on the Record Date in the name of DTC, such
distribution shall be made by wire transfer in immediately available funds to
the account designated by DTC.
<PAGE>   34
                                      -29-

            (c) The Trustee shall cause notice of each Special Payment to be
mailed to each Certificateholder at his address as it appears in the Register.
In the event of redemption or purchase of Equipment Notes held in the Trust,
such notice shall be mailed not less than 20 days prior to the Special
Distribution Date for the Special Payment resulting from such redemption or
purchase, which Special Distribution Date shall be the date of such redemption
or purchase. In the event of the payment of a Special Redemption Premium by the
Company to the Trustee under the Note Purchase Agreement, such notice shall be
mailed, together with the notice by the Escrow Paying Agent under Section 2.06
of the Escrow Agreement, not less than 20 days prior to the Special Distribution
Date for such amount, which Special Distribution Date shall be the Final
Withdrawal Date. In the case of any other Special Payments, such notice shall be
mailed as soon as practicable after the Trustee has confirmed that it has
received funds for such Special Payment, stating the Special Distribution Date
for such Special Payment which shall occur not less than 20 days after the date
of such notice and as soon as practicable thereafter. Notices mailed by the
Trustee shall set forth:

                         (i) the Special Distribution Date and the Record Date
            therefor (except as otherwise provided in Section 11.01),

                         (ii) the amount of the Special Payment for each $1,000
            face amount Certificate and the amount thereof constituting
            principal, premium, if any, and interest,

                         (iii) the reason for the Special Payment, and

                         (iv) if the Special Distribution Date is the same date
            as a Regular Distribution Date, the total amount to be received on
            such date for each $1,000 face amount Certificate.

If the amount of (i) premium, if any, payable upon the redemption or purchase of
an Equipment Note or (ii) the Special Redemption Premium, if any, has not been
calculated at the time that the Trustee mails notice of a Special Payment, it
shall be sufficient if the notice sets forth the other amounts to be distributed
and states that any premium received will also be distributed.

            If any redemption of the Equipment Notes held in the Trust is
canceled, the Trustee, as soon as possible after learning thereof, shall cause
notice thereof to be mailed to each Certificateholder at its address as it
appears on the Register.

            Section 4.03. Statements to Certificateholders. (a) On each
Distribution Date, the Trustee will include with each distribution to
Certificateholders of a Scheduled Payment or Special Payment, as the case may
be, a statement setting forth the information provided below (in the case of a
Special Payment, including any Special Redemption Premium, reflecting in part
the information provided by the Escrow Paying Agent under the Escrow Agreement).
Such statement shall set forth (per $1,000 face amount Certificate as to (ii),
(iii), (iv) and (v) below) the following information:

            (i) the aggregate amount of funds distributed on such Distribution
      Date hereunder and under the Escrow Agreement, indicating the amount
      allocable to each source;
<PAGE>   35
                                      -30-

            (ii) the amount of such distribution hereunder allocable to
      principal and the amount allocable to premium (including the Special
      Redemption Premium), if any;

            (iii) the amount of such distribution hereunder allocable to
      interest; and

            (iv) the amount of such distribution under the Escrow Agreement
      allocable to interest;

            (v) the amount of such distribution under the Escrow Agreement
      allocable to Deposits; and

            (vi) the Pool Balance and the Pool Factor.

            With respect to the Certificates registered in the name of DTC, on
the Record Date prior to each Distribution Date, the Trustee will request from
DTC a securities position listing setting forth the names of all Agent Members
reflected on DTC's books as holding interests in the Certificates on such Record
Date. On each Distribution Date, the Trustee will mail to each such Agent Member
the statement described above and will make available additional copies as
requested by such Agent Member for forwarding to holders of interests in the
Certificates.

            (b) Within a reasonable period of time after the end of each
calendar year but not later than the latest date permitted by law, the Trustee
shall furnish to each Person who at any time during such calendar year was a
Certificateholder of record a statement containing the sum of the amounts
determined pursuant to clauses (a)(i), (a)(ii), (a)(iii), (a)(iv) and (a)(v)
above for such calendar year or, in the event such Person was a
Certificateholder of record during a portion of such calendar year, for such
portion of such year, and such other items as are readily available to the
Trustee and which a Certificateholder shall reasonably request as necessary for
the purpose of such Certificateholder's preparation of its federal income tax
returns. Such statement and such other items shall be prepared on the basis of
information supplied to the Trustee by the Agent Members and shall be delivered
by the Trustee to such Agent Members to be available for forwarding by such
Agent Members to the holders of interests in the Certificates in the manner
described in Section 4.03(a).

            (c) Promptly following (i) the Transfer Date, if there has been any
change in the information set forth in clauses (x), (y) and (z) below from that
set forth in page 69 of the Offering Circular, and (ii) any early redemption or
purchase of, or any default in the payment of principal or interest in respect
of, any of the Equipment Notes held in the Trust, or any Final Withdrawal, the
Trustee shall furnish to Certificateholders of record on such date a statement
setting forth (x) the expected Pool Balances for each subsequent Regular
Distribution Dates following the Delivery Period Termination Date, (y) the
related Pool Factors for such Regular Distribution Dates and (z) the expected
principal distribution schedule of the Equipment Notes, in the aggregate, held
as Trust Property at the date of such notice. With respect to the Certificates
registered in the name of DTC, on the Transfer Date, the Trustee will request
from DTC a securities position listing setting forth the names of all Agent
Members reflected on DTC's books as holding interests in the "Certificates" (as
defined in the Related Pass Through Trust Agreement) on the Delivery Period
Termination Date. The Trustee will mail to each such
<PAGE>   36
                                      -31-

Agent Member the statement described above and will make available additional
copies as requested by such Agent Member for forwarding to holders of interests
in the Certificates.

            Section 4.04. Investment of Special Payment Moneys. Any money
received by the Trustee pursuant to Section 4.01(b) representing a Special
Payment which is not distributed on the date received shall, to the extent
practicable, be invested in Permitted Investments by the Trustee pending
distribution of such Special Payment pursuant to Section 4.02. Any investment
made pursuant to this Section 4.04 shall be in such Permitted Investments having
maturities not later than the date that such moneys are required to be used to
make the payment required under Section 4.02 on the applicable Special
Distribution Date and the Trustee shall hold any such Permitted Investments
until maturity. The Trustee shall have no liability with respect to any
investment made pursuant to this Section 4.04, other than by reason of the
willful misconduct or negligence of the Trustee. All income and earnings from
such investments shall be distributed on such Special Distribution Date as part
of such Special Payment.


                                    ARTICLE V

                                   THE COMPANY

            Section 5.01. Maintenance of Corporate Existence. The Company, at
its own cost and expense, will do or cause to be done all things necessary to
preserve and keep in full force and effect its corporate existence, except as
permitted by Section 5.02.

            Section 5.02. Consolidation, Merger, Etc. The Company shall not
consolidate with or merge into any other corporation or convey, transfer or
lease substantially all of its assets as an entirety to any Person unless:

            (a) the corporation formed by such consolidation or into which the
      Company is merged or the Person that acquires by conveyance, transfer or
      lease substantially all of the assets of the Company as an entirety shall
      be (i) organized and validly existing under the laws of the United States
      of America or any state thereof or the District of Columbia, (ii) a
      "citizen of the United States" as defined in 49 U.S.C. 40102(a)(15), as
      amended, and (iii) a United States certificated air carrier, if and so
      long as such status is a condition of entitlement to the benefits of
      Section 1110 of the Bankruptcy Reform Act of 1978, as amended (11 U.S.C.
      Section 1110);

            (b) the corporation formed by such consolidation or into which the
      Company is merged or the Person which acquires by conveyance, transfer or
      lease substantially all of the assets of the Company as an entirety shall
      execute and deliver to the Trustee a duly authorized, valid, binding and
      enforceable agreement in form and substance reasonably satisfactory to the
      Trustee containing an assumption by such successor corporation or Person
      of the due and punctual performance and observance of each covenant and
      condition of this Agreement, the Other Pass Through Trust Agreements and
      each Financing Document to be performed or observed by the Company; and

            (c) the Company shall have delivered to the Trustee an Officer's
      Certificate of the Company reasonably satisfactory to the Trustee, stating
      that such consolidation,
<PAGE>   37
                                      -32-

      merger, conveyance, transfer or lease and the assumption agreement
      mentioned in clause (b) above comply with this Section 5.02 and that all
      conditions precedent herein provided for relating to such transaction have
      been complied with.

            Upon any consolidation or merger, or any conveyance, transfer or
lease of substantially all of the assets of the Company as an entirety in
accordance with this Section 5.02, the successor corporation or Person formed by
such consolidation or into which the Company is merged or to which such
conveyance, transfer or lease is made shall succeed to, and be substituted for,
and may exercise every right and power of, the Company under this Agreement with
the same effect as if such successor corporation or Person had been named as the
Company herein. No such conveyance, transfer or lease of substantially all of
the assets of the Company as an entirety shall have the effect of releasing any
successor corporation or Person which shall have become such in the manner
prescribed in this Section 5.02 from its liability in respect of this Agreement
and any Financing Document to which it is a party.


                                   ARTICLE VI

                                     DEFAULT

            Section 6.01. Events of Default. (a) Exercise of Remedies. Upon the
occurrence and during the continuation of any Indenture Default under any
Indenture, the Trustee may, to the extent it is the Controlling Party at such
time (as determined pursuant to the Intercreditor Agreement), direct the
exercise of remedies as provided in the Intercreditor Agreement.

            (b) Purchase Rights of Certificateholders. (i) At any time after the
      occurrence and during the continuance of a Triggering Event, each
      Certificateholder shall have the right to purchase, for the purchase price
      set forth in the Class A Trust Agreement, all, but not less than all, of
      the Class A Certificates upon ten days' written notice to the Class A
      Trustee and each other Certificateholder, provided that (i) if prior to
      the end of such ten-day period any other Certificateholder notifies such
      purchasing Certificateholder that such other Certificateholder wants to
      participate in such purchase, then such other Certificateholder may join
      with the purchasing Certificateholder to purchase all, but not less than
      all, of the Class A Certificates pro rata based on the Fractional
      Undivided Interest in the Trust held by each such Certificateholder and
      (ii) if prior to the end of such ten-day period any other
      Certificateholder fails to notify the purchasing Certificateholder of such
      other Certificateholder's desire to participate in such a purchase, then
      such other Certificateholder shall lose its right to purchase the Class A
      Certificates pursuant to this Section 6.01(b); and

            (ii) by acceptance of its Certificate, each Certificateholder agrees
      that at any time after the occurrence and during the continuation of a
      Triggering Event,

                  (A) each Class C Certificateholder shall have the right (which
            shall not expire upon any purchase of the Class A Certificates
            pursuant to clause (b)(i) above) to purchase all, but not less than
            all, of the Class A Certificates and the Certificates upon ten days'
            written notice to the Class A Trustee, the Trustee and
<PAGE>   38
                                      -33-

            each other Class C Certificateholder, provided that (1) if prior to
            the end of such ten-day period any other Class C Certificateholder
            notifies such purchasing Class C Certificateholder that such other
            Class C Certificateholder wants to participate in such purchase,
            then such other Class C Certificateholder may join with the
            purchasing Class C Certificateholder to purchase all, but not less
            than all, of the Class A Certificates and the Certificates pro rata
            based on the Fractional Undivided Interest in the Class C Trust,
            taken as a whole, held by each such Class C Certificateholder and
            (2) if prior to the end of such ten day period any other Class C
            Certificateholder fails to notify the purchasing Class C
            Certificateholder of such other Class C Certificateholder's desire
            to participate in such a purchase, then such other Class C
            Certificateholder shall lose its right to purchase the Certificates
            pursuant to this Section 6.01(b); and

                  (B) each Class D Certificateholder shall have the right (which
            shall not expire upon any purchase of the Class A Certificates
            pursuant to clause (b)(i) above or any purchase of the Class A
            Certificates and the Certificates pursuant to clause (b)(ii)(A)
            above) to purchase all, but not less than all, of the Class A
            Certificates, the Certificates and the Class C Certificates upon ten
            days' written notice to the Class A Trustee, the Trustee, the Class
            C Trustee and each other Class D Certificateholder, provided that
            (1) if prior to the end of such ten-day period any other Class D
            Certificateholder notifies such purchasing Class D Certificateholder
            that such other Class D Certificateholder wants to participate in
            such purchase, then such other Class D Certificateholder may join
            with the purchasing Class D Certificateholder to purchase all, but
            not less than all, of the Class A Certificates, the Certificates and
            the Class C Certificates pro rata based on the Fractional Undivided
            Interest in the Class D Trust, taken as a whole, held by each such
            Class D Certificateholder and (2) if prior to the end of such ten
            day period any other Class D Certificateholder fails to notify the
            purchasing Class D Certificateholder of such other Class D
            Certificateholder's desire to participate in such a purchase, then
            such other Class D Certificateholder shall lose its right to
            purchase the Certificates pursuant to this Section 6.01(b).

            The purchase price with respect to the Certificates shall be equal
to the Pool Balance of the Certificates, together with accrued and unpaid
interest thereon to the date of such purchase, without premium, but including
any other amounts then due and payable to the Certificateholders under this
Agreement, the Intercreditor Agreement, the Escrow Agreement or any Financing
Document or on or in respect of the Certificates; provided, however, that (i) if
such purchase occurs after the record date specified in Section 2.03(b) of the
Escrow Agreement relating to the distribution of unused Deposits and accrued and
unpaid interest thereunder, such purchase price shall be reduced by the
aggregate amount of unused deposits and interest to be distributed under the
Escrow Agreement (which deducted amounts shall remain distributable to, and may
be retained by, the Certificateholder as of such Record Date) and (ii) if such
purchase occurs after a Record Date, such purchase price shall be reduced by the
amount to be distributed hereunder on the related Distribution Date (which
deducted amounts shall remain distributable to, and may be retained by, the
Certificateholder as of such Record Date); provided further, that no such
purchase of Certificates shall be effective unless the purchaser(s) shall
certify to the Trustee that contemporaneously with such purchase, such
purchaser(s) is purchasing, pursuant to 
<PAGE>   39
                                      -34-

the terms of this Agreement and the Other Pass Through Trust Agreements, the
Class A Certificates, the Certificates and the Class C Certificates which are
senior to the securities held by such purchaser(s). Each payment of the purchase
price of the Certificates referred to in the first sentence hereof shall be made
to an account or accounts designated by the Trustee and each such purchase shall
be subject to the terms of this Section 6.01(b). Each Certificateholder agrees
by its acceptance of its Certificate that it will, subject to Section 3.04
hereof, upon payment from such Class C Certificateholder(s) or Class D
Certificateholder(s), as the case may be, of the purchase price set forth in the
first sentence of this paragraph, forthwith sell, assign, transfer and convey to
the purchaser(s) thereof (without recourse, representation or warranty of any
kind except for its own acts), all of the right, title, interest and obligation
of such Certificateholder in this Agreement, the Escrow Agreement, the Deposit
Agreement, the Intercreditor Agreement, the Liquidity Facility, the Financing
Documents and all Certificates and Escrow Receipts held by such
Certificateholder (excluding all right, title and interest under any of the
foregoing to the extent such right, title or interest is with respect to an
obligation not then due and payable as respects any action or inaction or state
of affairs occurring prior to such sale) and the purchaser shall assume all of
such Certificateholder's obligations under this Agreement, the Escrow Agreement,
the Deposit Agreement, the Intercreditor Agreement, the Liquidity Facility, the
Financing Documents and all such Certificates and Escrow Receipts. The
Certificates will be deemed to be purchased on the date payment of the purchase
price is made notwithstanding the failure of the Certificateholders to deliver
any Certificates (whether in the form of Definitive Certificates or beneficial
interests in Global Certificates) and, upon such a purchase, (i) the only rights
of the Certificateholders will be to deliver the Certificates to the
purchaser(s) and receive the purchase price for such Certificates and (ii) if
the purchaser(s) shall so request, such Certificateholder will comply with all
the provisions of Section 3.04 hereof to enable new Certificates to be issued to
the purchaser in such denominations as it shall request. All charges and
expenses in connection with the issuance of any such new Certificates shall be
borne by the purchaser thereof.

            As used in this Section 6.01(b), the terms "Class A Certificate",
"Class A Certificateholder", "Class A Trust", "Class A Trust Agreement", "Class
A Trustee", "Class C Certificate", "Class C Certificateholder", "Class C Trust",
"Class C Trustee", "Class D Certificate", and "Class D Trust", shall have the
respective meanings assigned to such terms in the Intercreditor Agreement.

            Section 6.02. Incidents of Sale of Equipment Notes. Upon any sale of
all or any part of the Equipment Notes made either under the power of sale given
under this Agreement or otherwise for the enforcement of this Agreement, the
following shall be applicable:

            (1) Certificateholders and Trustee May Purchase Equipment Notes. Any
      Certificateholder, the Trustee in its individual or any other capacity or
      any other Person may bid for and purchase any of the Equipment Notes, and
      upon compliance with the terms of sale, may hold, retain, possess and
      dispose of such Equipment Notes in their own absolute right without
      further accountability.

            (2) Receipt of Trustee Shall Discharge Purchaser. The receipt of the
      Trustee making such sale shall be a sufficient discharge to any purchaser
      for his purchase money, and, after paying such purchase money and
      receiving such receipt, such purchaser or its
<PAGE>   40
                                      -35-

      personal representative or assigns shall not be obliged to see to the
      application of such purchase money, or be in any way answerable for any
      loss, misapplication or non-application thereof.

            (3) Application of Moneys Received upon Sale. Any moneys collected
      by the Trustee upon any sale made either under the power of sale given by
      this Agreement or otherwise for the enforcement of this Agreement shall be
      applied as provided in Section 4.02.

            Section 6.03. Judicial Proceedings Instituted by Trustee; Trustee
May Bring Suit. If there shall be a failure to make payment of the principal of,
premium, if any, or interest on any Equipment Note, or if there shall be any
failure to pay Rent (as defined in the relevant Lease) under any Lease when due
and payable, then the Trustee, in its own name and as trustee of an express
trust, as holder of such Equipment Notes, to the extent permitted by and in
accordance with the terms of the Intercreditor Agreement and the Financing
Documents (subject to the rights of the applicable Owner Trustee or Owner
Participant to cure any such failure to pay principal of, premium, if any, or
interest on any Equipment Note or to pay Rent under any Lease in accordance with
the applicable Indenture), shall be entitled and empowered to institute any
suits, actions or proceedings at law, in equity or otherwise, for the collection
of the sums so due and unpaid on such Equipment Notes or under such Lease and
may prosecute any such claim or proceeding to judgment or final decree with
respect to the whole amount of any such sums so due and unpaid.

            Section 6.04. Control by Certificateholders. Subject to Section 6.03
and the Intercreditor Agreement, the Certificateholders holding Certificates
evidencing Fractional Undivided Interests aggregating not less than a majority
in interest in the Trust shall have the right to direct the time, method and
place of conducting any proceeding for any remedy available to the Trustee with
respect to the Trust or pursuant to the terms of the Intercreditor Agreement, or
exercising any trust or power conferred on the Trustee under this Agreement or
the Intercreditor Agreement, including any right of the Trustee as Controlling
Party under the Intercreditor Agreement or as holder of the Equipment Notes,
provided that:

            (1) such Direction shall not be in conflict with any rule of law or
      with this Agreement and would not involve the Trustee in personal
      liability or expense,

            (2) the Trustee shall not determine that the action so directed
      would be unjustly prejudicial to the Certificateholders not taking part in
      such Direction, and

            (3) the Trustee may take any other action deemed proper by the
      Trustee which is not inconsistent with such Direction.

            Section 6.05. Waiver of Past Defaults. Subject to the Intercreditor
Agreement, the Certificateholders holding Certificates evidencing Fractional
Undivided Interests aggregating not less than a majority in interest in the
Trust (i) may on behalf of all of the Certificateholders waive any past Event of
Default hereunder and its consequences or (ii) if the Trustee is the Controlling
Party, may direct the Trustee to instruct the applicable Loan Trustee to waive
any past Indenture Default under any Indenture and its consequences, and thereby
annul any
<PAGE>   41
                                      -36-

Direction given by such Certificateholders or the Trustee to such Loan Trustee
with respect thereto, except a default:

            (1) in the deposit of any Scheduled Payment or Special Payment under
      Section 4.01 or in the distribution of any payment under Section 4.02 on
      the Certificates, or

            (2) in the payment of the principal of (premium, if any) or interest
      on the Equipment Notes, or

            (3) in respect of a covenant or provision hereof which under Article
      IX cannot be modified or amended without the consent of each
      Certificateholder holding an Outstanding Certificate affected thereby.

            Upon any such waiver, such default shall cease to exist with respect
to the Certificates and any Event of Default arising therefrom shall be deemed
to have been cured for every purpose and any direction given by the Trustee on
behalf of the Certificateholders to the relevant Loan Trustee shall be annulled
with respect thereto; but no such waiver shall extend to any subsequent or other
default or Event of Default or impair any right consequent thereon. Upon any
such waiver, the Trustee shall vote the Equipment Notes issued under the
relevant Indenture to waive the corresponding Indenture Default.

            Section 6.06. Right of Certificateholders to Receive Payments Not to
Be Impaired. Anything in this Agreement to the contrary notwithstanding,
including, without limitation, Section 6.07 hereof, but subject to the
Intercreditor Agreement, the right of any Certificateholder to receive
distributions of payments required pursuant to Section 4.02 hereof on the
Certificates when due, or to institute suit for the enforcement of any such
payment on or after the applicable Regular Distribution Date or Special
Distribution Date, shall not be impaired or affected without the consent of such
Certificateholder.

            Section 6.07. Certificateholders May Not Bring Suit Except Under
Certain Conditions. A Certificateholder shall not have the right to institute
any suit, action or proceeding at law or in equity or otherwise with respect to
this Agreement, for the appointment of a receiver or for the enforcement of any
other remedy under this Agreement, unless:

            (1) such Certificateholder previously shall have given written
      notice to the Trustee of a continuing Event of Default;

            (2) Certificateholders holding Certificates evidencing Fractional
      Undivided Interests aggregating not less than 25% of the Trust shall have
      requested the Trustee in writing to institute such action, suit or
      proceeding and shall have offered to the Trustee indemnity as provided in
      Section 7.03(e);

            (3) the Trustee shall have refused or neglected to institute such an
      action, suit or proceeding for 60 days after receipt of such notice,
      request and offer of indemnity; and

            (4) no direction inconsistent with such written request shall have
      been given to the Trustee during such 60-day period by Certificateholders
      holding Certificates
<PAGE>   42
                                      -37-

      evidencing Fractional Undivided Interests aggregating not less than a
      majority in interest in the Trust.

            It is understood and intended that no one or more of the
Certificateholders shall have any right in any manner whatsoever hereunder or
under the Certificates to (i) surrender, impair, waive, affect, disturb or
prejudice any property in the Trust Property or the lien of any Indenture on any
property subject thereto, or the rights of the Certificateholders or the holders
of the Equipment Notes, (ii) obtain or seek to obtain priority over or
preference with respect to any other such Certificateholder or (iii) enforce any
right under this Agreement, except in the manner herein provided and for the
equal, ratable and common benefit of all the Certificateholders subject to the
provisions of this Agreement.

            Section 6.08. Remedies Cumulative. Every remedy given hereunder to
the Trustee or to any of the Certificateholders shall not be exclusive of any
other remedy or remedies, and every such remedy shall be cumulative and in
addition to every other remedy given hereunder or now or hereafter given by
statute, law, equity or otherwise.


                                   ARTICLE VII

                                   THE TRUSTEE

            Section 7.01. Certain Duties and Responsibilities. (a) Except during
the continuance of an Event of Default, the Trustee undertakes to perform such
duties as are specifically set forth in this Agreement, and no implied covenants
or obligations shall be read into this Agreement against the Trustee.

            (b) In case an Event of Default has occurred and is continuing, the
Trustee shall exercise such of the rights and powers vested in it by this
Agreement, and use the same degree of care and skill in their exercise, as a
prudent man would exercise or use under the circumstances in the conduct of its
own affairs.

            (c) No provision of this Agreement shall be construed to relieve the
Trustee from liability for its own negligent action, its own negligent failure
to act, or its own wilful misconduct, except that

            (1) this Subsection shall not be construed to limit the effect of
      Subsection (a) of this Section; and

            (2) the Trustee shall not be liable for any error of judgment made
      in good faith by a Responsible Officer of the Trustee, unless it shall be
      proved that the Trustee was negligent in ascertaining the pertinent facts.

            (d) Whether or not herein expressly so provided, every provision of
this Trust Agreement relating to the conduct or affecting the liability of or
affording protection to the Trustee shall be subject to the provisions of this
Section.
<PAGE>   43
                                      -38-

            Section 7.02. Notice of Defaults. As promptly as practicable after,
and in any event within 90 days after, the occurrence of any default (as such
term is defined below) hereunder, the Trustee shall transmit by mail to the
Company, the Owner Trustees, the Owner Participants, the Loan Trustees and the
Certificateholders in accordance with Section 313(c) of the Trust Indenture Act,
notice of such default hereunder known to the Trustee, unless such default shall
have been cured or waived; provided, however, that, except in the case of a
default on the payment of the principal, premium, if any, or interest on any
Equipment Note held in the Trust, the Trustee shall be protected in withholding
such notice if and so long as the board of directors, the executive committee or
a trust committee of directors and/or Responsible Officers of the Trustee in
good faith determine that the withholding of such notice is in the interests of
the Certificateholders. For the purpose of this Section, the term "default"
means any event that is, or after notice or lapse of time or both would become,
an Event of Default.

            Section 7.03. Certain Rights of Trustee. Subject to the provisions
of Section 315 of the Trust Indenture Act:

            (a) the Trustee may rely and shall be protected in acting or
      refraining from acting in reliance upon any resolution, certificate,
      statement, instrument, opinion, report, notice, request, direction,
      consent, order, bond, debenture or other paper or document believed by it
      to be genuine and to have been signed or presented by the proper party or
      parties;

            (b) any request or direction of the Company mentioned herein shall
      be sufficiently evidenced by a written description of the subject matter
      thereof accompanied by an Officer's Certificate and an Opinion of Counsel
      as provided in Section 1.02 of this Agreement;

            (c) whenever in the administration of this Agreement the Trustee
      shall deem it desirable that a matter be proved or established prior to
      taking, suffering or omitting any action hereunder, the Trustee (unless
      other evidence be herein specifically prescribed) may, in the absence of
      bad faith on its part, rely upon an Officer's Certificate of the Company,
      any Owner Trustee or any Loan Trustee;

            (d) the Trustee may consult with counsel and the advice of such
      counsel or any Opinion of Counsel shall be full and complete authorization
      and protection in respect of any action taken, suffered or omitted by it
      hereunder in good faith and in reliance thereon;

            (e) the Trustee shall be under no obligation to exercise any of the
      rights or powers vested in it by this Agreement at the Direction of any of
      the Certificateholders pursuant to this Agreement, unless such
      Certificateholders shall have offered to the Trustee reasonable security
      or indemnity against the cost, expenses and liabilities which might be
      incurred by it in compliance with such Direction;

            (f) the Trustee shall not be bound to make any investigation into
      the facts or matters stated in any resolution, certificate, statement,
      instrument, opinion, report, notice, request, direction, consent, order,
      bond, debenture or other paper or document;
<PAGE>   44
                                      -39-

            (g) the Trustee may execute any of the trusts or powers under this
      Agreement or perform any duties under this Agreement either directly or by
      or through agents or attorneys, and the Trustee shall not be responsible
      for any misconduct or negligence on the part of any agent or attorney
      appointed with due care by it under this Agreement;

            (h) the Trustee shall not be liable with respect to any action taken
      or omitted to be taken by it in good faith in accordance with the
      Direction of the Certificateholders holding Certificates evidencing
      Fractional Undivided Interests aggregating not less than a majority in
      interest in the Trust relating to the time, method and place of conducting
      any proceeding for any remedy available to the Trustee, or exercising any
      trust or power conferred upon the Trustee, under this Agreement; and

            (i) the Trustee shall not be required to expend or risk its own
      funds in the performance of any of its duties under this Agreement, or in
      the exercise of any of its rights or powers, if it shall have reasonable
      grounds for believing that repayment of such funds or adequate indemnity
      against such risk is not reasonably assured to it.

            Section 7.04. Not Responsible for Recitals or Issuance of
Certificates. The recitals contained herein and in the Certificates, except the
certificates of authentication, shall not be taken as the statements of the
Trustee, and the Trustee assumes no responsibility for their correctness.
Subject to Section 7.15, the Trustee makes no representations as to the validity
or sufficiency of this Agreement, any Equipment Notes, the Intercreditor
Agreement, the Deposit Agreement, the Escrow Agreement, the Certificates or any
other Financing Document, except that the Trustee hereby represents and warrants
that this Agreement has been, and the Intercreditor Agreement, the Registration
Rights Agreement, the Note Purchase Agreement, the Escrow Agreement and each
Certificate will be, executed, authenticated and delivered by one of its
officers who is duly authorized to execute, authenticate and deliver such
document on its behalf.

            Section 7.05. May Hold Certificates. The Trustee, any Paying Agent,
Registrar or any of their Affiliates or any other agent in their respective
individual or any other capacity may become the owner or pledgee of Certificates
and, subject to Sections 310(b) and 311 of the Trust Indenture Act, if
applicable, may otherwise deal with the Company, the Owner Trustees or the Loan
Trustees with the same rights it would have if it were not Trustee, Paying
Agent, Registrar or such other agent.

            Section 7.06. Money Held in Trust. Money held by the Trustee or the
Paying Agent in trust hereunder need not be segregated from other funds except
to the extent required herein or by law and neither the Trustee nor the Paying
Agent shall have any liability for interest upon any such moneys except as
provided for herein.

            Section 7.07. Compensation and Reimbursement. The Company agrees:

            (1) to pay, or cause to be paid, to the Trustee from time to time
      reasonable compensation for all services rendered by it hereunder as set
      forth in a written fee letter dated the date hereof between the Company
      and the Trustee, which letter is incorporated
<PAGE>   45
                                      -40-

      herein by reference (which compensation shall not be limited by any
      provision of law in regard to the compensation of a trustee of an express
      trust);

            (2) except as otherwise expressly provided herein, to reimburse, or
      cause to be reimbursed, the Trustee upon its request for all reasonable
      out-of-pocket expenses, disbursements and advances incurred or made by the
      Trustee in accordance with any provision of this Agreement (including the
      reasonable compensation and the expenses and disbursements of its agents
      and counsel), except any such expense, disbursement or advance as may be
      attributable to its undertaking its normal administrative functions, or
      its negligence, willful misconduct or bad faith or as may be incurred due
      to the Trustee's breach of its representations and warranties set forth in
      Section 7.15; and

            (3) to indemnify, or cause to be indemnified, the Trustee for, and
      to hold it harmless against, any loss, liability, expense or Tax (other
      than for or with respect to any Unindemnified Tax) incurred without
      negligence, willful misconduct or bad faith, on its part, arising out of
      or in connection with the acceptance or administration of this Trust,
      including the costs and expenses of defending itself against any claim or
      liability in connection with the exercise or performance of any of its
      powers or duties hereunder, except for any such loss, liability or expense
      incurred by reason of the Trustee's breach of its covenants hereunder or
      under any Financing Document to which it is a party or its representations
      and warranties set forth in Section 7.15 or in any other Financing
      Document, the authorization or giving or withholding of any future
      amendments, supplements, waivers or consents with respect hereto or any of
      the Financing Documents, which amendments, supplements, waivers or
      consents are not required pursuant to the terms of the Financing Documents
      and not requested by the Company, any loss of tax benefits, any
      Unindemnified Tax, or increase in tax liability under any tax law whether
      or not the Company is required to indemnify thereof or pursuant to this
      Agreement or any costs associated with overhead or normal administration
      hereunder or any voluntary resignation pursuant to Section 7.09.

            With respect to paragraph (3) above, the Trustee shall notify the
Company promptly of any claim for which it may seek indemnity and the Company
shall make payment on any such claim within 30 days of written demand thereof
(delivered together with supporting documentation). The Company shall defend the
claim and the Trustee shall cooperate in the defense. The Trustee may have
separate counsel with the consent of the Company and the Company will pay the
reasonable fees and expenses of such counsel. The Company need not pay for any
settlement made, in settlement or otherwise, without its consent.

            With respect to any Tax other than an Unindemnified Tax, the Trustee
shall be entitled to reimbursement from, and shall have a lien prior to the
Certificates upon, the Trust Property for any such Tax incurred without
negligence, bad faith or willful misconduct, on its part, arising out of or in
connection with the acceptance or administration of such Trust (other than any
Tax attributable to the Trustee's compensation for serving as such), including
any costs and expenses incurred in contesting the imposition of any such Tax. If
the Trustee reimburses itself from the Trust Property of such Trust for any such
Tax, it will mail a brief report within 30 days setting forth the circumstances
thereof to all Certificateholders as their names and addresses appear in the
Register.
<PAGE>   46
                                      -41-

            Section 7.08. Corporate Trustee Required; Eligibility. There shall
at all times be a Trustee hereunder which shall be eligible to act as a trustee
under Section 310(a) of the Trust Indenture Act and shall have a combined
capital and surplus of at least $75,000,000 (or a combined capital and surplus
in excess of $5,000,000 and the obligations of which, whether now in existence
or hereafter incurred, are fully and unconditionally guaranteed by a corporation
organized and doing business under the laws of the United States, any state or
territory thereof or of the District of Columbia and having a combined capital
and surplus of at least $75,000,000). If such corporation publishes reports of
conditions at least annually, pursuant to law or to the requirements of federal,
state, territorial or District of Columbia supervising or examining authority,
then for the purposes of this Section 7.08, the combined capital and surplus of
such corporation shall be deemed to be its combined capital and surplus as set
forth in its most recent report of conditions so published.

            In case at any time the Trustee shall cease to be eligible in
accordance with the provisions of this Section 7.08 to act as Trustee, the
Trustee shall resign immediately as Trustee in the manner and with the effect
specified in Section 7.09.

            Section 7.09. Resignation and Removal; Appointment of Successor. (a)
No resignation or removal of the Trustee and no appointment of a successor
Trustee pursuant to this Article shall become effective until the acceptance of
appointment by the successor Trustee under Section 7.10.

            (b) The Trustee may resign at any time as trustee by giving prior
written notice thereof to the Company, the Authorized Agents, the Owner Trustees
and the Loan Trustees. If an instrument of acceptance by a successor Trustee
shall not have been delivered to the Company, the Authorized Agents, the Owner
Trustees, the Loan Trustees and the Trustee within 30 days after the giving of
such notice of resignation, the resigning Trustee may petition any court of
competent jurisdiction for the appointment of a successor Trustee.

            (c) The Trustee may be removed at any time by Direction of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not less than a majority in interest in the Trust
delivered to the Trustee and to the Company, the Owner Trustees and the Loan
Trustees.

            (d) If at any time:

            (1) the Trustee shall fail to comply with Section 310 of the Trust
      Indenture Act, if applicable, after written request therefor by the
      Company or by any Certificateholder who has been a bona fide
      Certificateholder for at least six months; or

            (2) the Trustee shall cease to be eligible under Section 7.08 and
      shall fail to resign after written request therefor by the Company or by
      any such Certificateholder; or

            (3) the Trustee shall become incapable of acting or shall be
      adjudged a bankrupt or insolvent or a receiver of the Trustee or of its
      property shall be appointed or any public officer shall take charge or
      control of the Trustee or of its property or affairs for the purpose of
      rehabilitation, conservation or liquidation;
<PAGE>   47
                                      -42-

then, in any case, (i) the Company may remove the Trustee or (ii) any
Certificateholder who has been a bona fide Certificateholder for at least six
months may, on behalf of itself and all others similarly situated, petition any
court of competent jurisdiction for the removal of the Trustee and the
appointment of a successor Trustee.

            (e) If a Responsible Officer of the Trustee shall obtain actual
knowledge of an Avoidable Tax which has been or is likely to be asserted, the
Trustee shall promptly notify the Company and shall, within 30 days of such
notification, resign hereunder unless within such 30-day period the Trustee
shall have received notice that the Company has agreed to pay such tax. The
Company shall promptly appoint a successor Trustee in a jurisdiction where there
are no Avoidable Taxes.

            (f) If the Trustee shall resign, be removed or become incapable of
acting or if a vacancy shall occur in the office of the Trustee for any cause,
the Company shall promptly appoint a successor Trustee. If, within one year
after such resignation, removal or incapability, or other occurrence of such
vacancy, a successor Trustee shall be appointed by Direction of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not less than a majority in interest in the Trust
delivered to the Company, the Owner Trustees, the Loan Trustees and the retiring
Trustee, and the Company approves such appointment, which approval shall not be
unreasonably withheld, then the successor Trustee so appointed shall, forthwith
upon its acceptance of such appointment, become the successor Trustee and
supersede the successor Trustee appointed as provided above. If no successor
Trustee shall have been so appointed as provided above and accepted appointment
in the manner hereinafter provided, any Certificateholder who has been a bona
fide Certificateholder for at least six months may, on behalf of himself and all
others similarly situated, petition any court of competent jurisdiction for the
appointment of a successor Trustee.

            (g) The successor Trustee shall give notice of the resignation and
removal of the Trustee and appointment of the successor Trustee by mailing
written notice of such event by first-class mail, postage prepaid, to the
Certificateholders as their names and addresses appear in the Register. Each
notice shall include the name of such successor Trustee and the address of its
Corporate Trust Office.

            Section 7.10. Acceptance of Appointment by Successor. Every
successor Trustee appointed hereunder shall execute and deliver to the Company,
the Authorized Agents, the Owner Trustees and the Loan Trustees and to the
retiring Trustee an instrument accepting such appointment, and thereupon the
resignation or removal of the retiring Trustee shall become effective and such
successor Trustee, without any further act, deed or conveyance, shall become
vested with all the rights, powers, trusts and duties of the retiring Trustee;
but, on request of the Company or the successor Trustee, such retiring Trustee
shall execute and deliver an instrument transferring to such successor Trustee
all such rights, powers and trusts of the retiring Trustee and shall duly
assign, transfer and deliver to such successor Trustee all Trust Property held
by such retiring Trustee hereunder, subject nevertheless to its lien, if any,
provided for in Section 7.07. Upon request of any such successor Trustee, the
Company, the retiring Trustee and such successor Trustee shall execute and
deliver any and all instruments containing such provisions as shall be necessary
or desirable to transfer and confirm to, and for more fully and certainly
vesting in, such successor Trustee all such rights, powers and trusts.
<PAGE>   48
                                      -43-

            No institution shall accept its appointment as a Trustee hereunder
unless at the time of such acceptance such institution shall be qualified and
eligible under this Article VII.

            Section 7.11. Merger, Conversion, Consolidation or Succession to
Business. Any corporation into which the Trustee may be merged or converted or
with which it may be consolidated, or any corporation resulting from any merger,
conversion or consolidation to which the Trustee shall be a party, or any
corporation succeeding to all or substantially all of the corporate trust
business of the Trustee, shall be the successor of the Trustee hereunder,
provided such corporation shall be otherwise qualified and eligible under this
Article VII, without the execution or filing of any paper or any further act on
the part of any of the parties hereto. In case any Certificates shall have been
executed or authenticated, but not delivered, by the Trustee then in office, any
successor by merger, conversion or consolidation to such authenticating Trustee
may adopt such execution or authentication and deliver the Certificates so
executed or authenticated with the same effect as if such successor Trustee had
itself executed or authenticated such Certificates.

            Section 7.12. Maintenance of Agencies. (a) There shall at all times
be maintained an office or agency in the location set forth in Section 12.03
where Certificates may be presented or surrendered for registration of transfer
or for exchange, and for payment thereof and where notices and demands to or
upon the Trustee in respect of such certificates or this Agreement may be
served; provided, however, that, if it shall be necessary that the Trustee
maintain an office or agency in another location (e.g., the Certificates shall
be represented by Definitive Certificates and shall be listed on a national
securities exchange), the Trustee will make all reasonable efforts to establish
such an office or agency. Written notice of the location of each such other
office or agency and of any change of location thereof shall be given by the
Trustee to the Company, the Owner Trustees, the Loan Trustees (in the case of
any Owner Trustee or Loan Trustee, at its address specified in the Financing
Documents or such other address as may be notified to the Trustee) and the
Certificateholders. In the event that no such office or agency shall be
maintained or no such notice of location or of change of location shall be
given, presentations and demands may be made and notices may be served at the
Corporate Trust Office of the Trustee.

            (b) There shall at all times be a Registrar and a Paying Agent
hereunder with respect to the Certificates. Each such Authorized Agent shall be
a bank or trust company, shall be a corporation organized and doing business
under the laws of the United States or any state, with a combined capital and
surplus of at least $75,000,000, or, if the Trustee shall be acting as the
Registrar or Paying Agent hereunder, a corporation having a combined capital and
surplus in excess of $5,000,000, the obligations of which are guaranteed by a
corporation organized and doing business under the laws of the United States or
any state, with a combined capital and surplus of at least $75,000,000, and
shall be authorized under such laws to exercise corporate trust powers, subject
to supervision by Federal or state authorities. The Trustee shall initially be
the Paying Agent and, as provided in Section 3.04, Registrar hereunder with
respect to the Certificates. Each Registrar shall furnish to the Trustee, at
stated intervals of not more than six months, and at such other times as the
Trustee may request in writing, a copy of the Register maintained by such
Registrar.
<PAGE>   49
                                      -44-

            (c) Any corporation into which any Authorized Agent may be merged or
converted or with which it may be consolidated, or any corporation resulting
from any merger, consolidation or conversion to which any Authorized Agent shall
be a party, or any corporation succeeding to the corporate trust business of any
Authorized Agent, shall be the successor of such Authorized Agent hereunder, if
such successor corporation is otherwise eligible under this Section, without the
execution or filing of any paper or any further act on the part of the parties
hereto or such Authorized Agent or such successor corporation.

            (d) Any Authorized Agent may at any time resign by giving written
notice of resignation to the Trustee, the Company, the Owner Trustees and the
Loan Trustees. The Company may, and at the request of the Trustee shall, at any
time terminate the agency of any Authorized Agent by giving written notice of
termination to such Authorized Agent and to the Trustee. Upon the resignation or
termination of an Authorized Agent or in case at any time any such Authorized
Agent shall cease to be eligible under this Section (when, in either case, no
other Authorized Agent performing the functions of such Authorized Agent shall
have been appointed), the Company shall promptly appoint one or more qualified
successor Authorized Agents, reasonably satisfactory to the Trustee, to perform
the functions of the Authorized Agent which has resigned or whose agency has
been terminated or who shall have ceased to be eligible under this Section. The
Company shall give written notice of any such appointment made by it to the
Trustee, the Owner Trustees and the Loan Trustees; and in each case the Trustee
shall mail notice of such appointment to all Certificateholders as their names
and addresses appear on the Register.

            (e) The Company agrees to pay, or cause to be paid, from time to
time to each Authorized Agent reasonable compensation for its services and to
reimburse it for its reasonable expenses as set forth in the letter agreement
referred to in Section 7.07 hereof.

            Section 7.13. Money for Certificate Payments to Be Held in Trust.
All moneys deposited with any Paying Agent for the purpose of any payment on
Certificates shall be deposited and held in trust for the benefit of the
Certificateholders entitled to such payment, subject to the provisions of this
Section. Moneys so deposited and held in trust shall constitute a separate trust
fund for the benefit of the Certificateholders with respect to which such money
was deposited.

            The Trustee may at any time, for the purpose of obtaining the
satisfaction and discharge of this Agreement or for any other purpose, direct
any Paying Agent to pay to the Trustee all sums held in trust by such Paying
Agent, such sums to be held by the Trustee upon the same trusts as those upon
which such sums were held by such Paying Agent; and, upon such payment by any
Paying Agent to the Trustee, such Paying Agent shall be released from all
further liability with respect to such money.

            Section 7.14. Registration of Equipment Notes in Name of
Subordination Agent. The Trustee agrees that all Equipment Notes to be purchased
by the Trust shall be issued in the name of the Subordination Agent or its
nominee and held by the Subordination Agent in trust for the benefit of the
Certificateholders, or, if not so held, the Subordination Agent or its nominee
shall be reflected as the owner of such Equipment Notes in the register of the
issuer of such Equipment Notes.
<PAGE>   50
                                      -45-

            Section 7.15. Representations and Warranties of Trustee. The Trustee
hereby represents and warrants on the Transfer Date that:

            (a) the Trustee is a Delaware banking corporation organized and
      validly existing in good standing under the laws of the State of Delaware;

            (b) the Trustee has full power, authority and legal right to receive
      the Trust Property assigned by the Related Trustee, assume the obligations
      under, and perform, the Assignment and Assumption Agreement, this
      Agreement, the Intercreditor Agreement, the Registration Rights Agreement,
      the Escrow Agreement, the Note Purchase Agreement and the Financing
      Documents to which it is a party and has taken all necessary action to
      authorize such receipt, assumption and performance by it of the Assignment
      and Assumption Agreement, this Agreement, the Intercreditor Agreement, the
      Registration Rights Agreement, the Escrow Agreement, the Note Purchase
      Agreement and the Financing Documents to which it is a party;

            (c) the receipt of the Trust Property under the Assignment and
      Assumption Agreement and the performance by the Trustee of the Assignment
      and Assumption Agreement, this Agreement, the Intercreditor Agreement, the
      Registration Rights Agreement, the Escrow Agreement, the Note Purchase
      Agreement and the Financing Documents to which it is a party (i) will not
      violate any provision of United States federal law or the law of the state
      of the United States where it is located governing the banking and trust
      powers of the Trustee or any order, writ, judgment, or decree of any
      court, arbitrator or governmental authority applicable to the Trustee or
      any of its assets, (ii) will not violate any provision of the articles of
      association or by-laws of the Trustee, or (iii) will not violate any
      provision of, or constitute, with or without notice or lapse of time, a
      default under, or result in the creation or imposition of any lien on any
      properties included in the Trust Property pursuant to the provisions of
      any mortgage, indenture, contract, agreement or other undertaking to which
      it is a party, which violation, default or lien could reasonably be
      expected to have an adverse effect on the Trustee's performance or ability
      to perform its duties hereunder or thereunder or on the transactions
      contemplated herein or therein;

            (d) the receipt of the Trust Property under the Assignment and
      Assumption Agreement and the performance by the Trustee of the Assignment
      and Assumption Agreement, this Agreement, the Intercreditor Agreement, the
      Registration Rights Agreement, the Escrow Agreement, the Note Purchase
      Agreement, and the Financing Documents to which it is a party will not
      require the authorization, consent, or approval of, the giving of notice
      to, the filing or registration with, or the taking of any other action in
      respect of, any governmental authority or agency of the United States or
      the state of the United States where it is located regulating the banking
      and corporate trust activities of the Trustee; and

            (e) the Assignment and Assumption Agreement has been duly executed
      and delivered by the Trustee and this Agreement, the Assignment and
      Assumption Agreement, the Intercreditor Agreement, the Registration Rights
      Agreement, the Escrow Agreement, the Note Purchase Agreement, and the
      Financing Documents to which it is a
<PAGE>   51
                                      -46-

      party constitute the legal, valid, and binding agreements of the Trustee,
      enforceable against it in accordance with their respective terms, provided
      that enforceability may be limited by (i) applicable bankruptcy,
      insolvency, reorganization, moratorium or similar laws affecting the
      rights of creditors generally and (ii) general principles of equity,
      regardless of whether applied in a proceeding in equity or at law.

            Section 7.16. Withholding Taxes, Information Reporting. The Trustee,
as trustee of the grantor trust created by this Agreement, shall exclude and
withhold from each distribution of principal, premium, if any, and interest and
other amounts due under this Agreement or under the Certificates any and all
withholding taxes applicable thereto as required by law. The Trustee agrees to
act as such withholding agent and, in connection therewith, whenever any present
or future taxes or similar charges are required to be withheld with respect to
any amounts payable in respect of the Certificates, to withhold such amounts and
timely pay the same to the appropriate authority in the name of and on behalf of
the Certificateholders, that it will file any necessary withholding tax returns
or statements when due, and that, as promptly as possible after the payment
thereof, it will deliver to each such Certificateholder appropriate
documentation showing the payment thereof, together with such additional
documentary evidence as such Certificateholders may reasonably request from time
to time. The Trustee agrees to file any other information reports as it may be
required to file under United States law. Each Certificateholder or Investor
that is not a United States person within the meaning of section 7701(a)(30) of
the Internal Revenue Code, as amended, by its acceptance of a Certificate or a
beneficial interest therein, agrees to indemnify and hold harmless the Trust and
the Trustee from and against any improper failure to withhold taxes from amounts
payable to it or for its benefit, other than an improper failure attributable to
the gross negligence or willful misconduct of the Trustee.

            Section 7.17. Trustee's Liens. The Trustee in its individual
capacity agrees that it will at its own cost and expense promptly take any
action as may be necessary to duly discharge and satisfy in full any mortgage,
pledge, lien, charge, encumbrance, security interest or claim ("Trustee's
Liens") on or with respect to the Trust Property which is attributable to the
Trustee either (i) in its individual capacity and which is unrelated to the
transactions contemplated by this Agreement, the Intercreditor Agreement, the
Note Purchase Agreement or the Financing Documents, or (ii) as Trustee hereunder
or in its individual capacity and which arises out of acts or omissions on the
part of the Trustee which are not contemplated by this Agreement.

            Section 7.18. Preferential Collection of Claims. The Trustee shall
comply with Section 311(a) of the Trust Indenture Act, excluding any creditor
relationship listed in Section 311(b) of the Trust Indenture Act. If the Trustee
shall resign or be removed as Trustee, it shall be subject to Section 311(a) of
the Trust Indenture Act to the extent provided therein.


                                  ARTICLE VIII

               CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE

            Section 8.01. The Company to Furnish Trustee with Names and
Addresses of Certificateholders. The Company will furnish to the Trustee within
15 days after each Record
<PAGE>   52
                                      -47-

Date with respect to a Scheduled Payment, and at such other times as the Trustee
may request in writing within 30 days after receipt by the Company of any such
request, a list, in such form as the Trustee may reasonably require, of all
information in the possession or control of the Company as to the names and
addresses of the Certificateholders, in each case as of a date not more than 15
days prior to the time such list is furnished; provided, however, that so long
as the Trustee is the sole Registrar, no such list need be furnished; and
provided further, however, that no such list need be furnished for so long as a
copy of the Register is being furnished to the Trustee pursuant to Section 7.12.

            Section 8.02. Preservation of Information; Communications to
Certificateholders. The Trustee shall preserve, in as current a form as is
reasonably practicable, the names and addresses of Certificateholders contained
in the most recent list furnished to the Trustee as provided in Section 7.12 or
Section 8.01, as the case may be, and the names and addresses of
Certificateholders received by the Trustee in its capacity as Registrar, if so
acting. The Trustee may destroy any list furnished to it as provided in Section
7.12 or Section 8.01, as the case may be, upon receipt of a new list so
furnished.

            Section 8.03. Reports by Trustee. Within 60 days after May 15 of
each year commencing with the first full year following the date hereof, the
Trustee shall transmit to the Certificateholders, as provided in Section 313(c)
of the Trust Indenture Act, a brief report dated as of such May 15, if required
by Section 313(a) of the Trust Indenture Act.

            Section 8.04. Reports by the Company. The Company shall:

            (a) file with the Trustee, within 30 days after the Company is
      required to file the same with the SEC, copies of the annual reports and
      of the information, documents and other reports (or copies of such
      portions of any of the foregoing as the SEC may from time to time by rules
      and regulations prescribe) which the Company is required to file with the
      SEC pursuant to section 13 or section 15(d) of the Securities Exchange Act
      of 1934, as amended; or, if the Company is not required to file
      information, documents or reports pursuant to either of such sections,
      then to file with the Trustee and the SEC, in accordance with rules and
      regulations prescribed by the SEC, such of the supplementary and periodic
      information, documents and reports which may be required pursuant to
      section 13 of the Securities Exchange Act of 1934, as amended, in respect
      of a security listed and registered on a national securities exchange as
      may be prescribed in such rules and regulations;

            (b) during any period, prior to the consummation of the Exchange
      Offer and during which the Shelf Registration Statement is not in effect,
      in which the Company is not subject to Section 13(a), 13(c) or 15(d) under
      the Securities Exchange Act of 1934, make available to any Holder of the
      Certificates in connection with any sale thereof and any prospective
      purchaser of the Certificates from such Holder, in each case upon request,
      the information specified in, and meeting the requirements of, Rule
      144A(d)(4) under the Securities Act but only for so long as any of the
      Certificates remain outstanding and are "restricted securities" within the
      meaning of Rule 144(a)(3) under the Securities Act and, in any event, only
      until the second anniversary of the Issuance Date;
<PAGE>   53
                                      -48-

            (c) file with the Trustee and the SEC, in accordance with the rules
      and regulations prescribed by the SEC, such additional information,
      documents and reports with respect to compliance by the Company with the
      conditions and covenants provided for in this Agreement, as may be
      required by such rules and regulations, including, in the case of annual
      reports, if required by such rules and regulations, certificates or
      opinions of independent public accountants, conforming to the requirements
      of Section 1.02;

            (d) transmit to all Certificateholders, in the manner and to the
      extent provided in Section 313(c) of the Trust Indenture Act such
      summaries of any information, documents and reports required to be filed
      by the Company pursuant to subsections (a) and (c) of this Section 8.04 as
      may be required by rules and regulations prescribed by the SEC; and

            (e) furnish to the Trustee, not less often than annually, a brief
      certificate from the principal executive officer, principal financial
      officer, any Vice President (or more senior ranking officer) or the
      principal accounting officer as to his or her knowledge of the Company's
      compliance with all conditions and covenants under this Agreement (it
      being understood that for purposes of this paragraph (e), such compliance
      shall be determined without regard to any period of grace or requirement
      of notice provided under this Agreement).


                                   ARTICLE IX

                             SUPPLEMENTAL AGREEMENTS

            Section 9.01. Supplemental Agreements Without Consent of
Certificateholders. Without the consent of the Certificateholders, the Company
may (but will not be required to), and the Trustee (subject to Section 9.03)
shall, at the Company's request, at any time and from time to time, enter into
one or more agreements supplemental hereto or, if applicable, to the
Intercreditor Agreement, the Escrow Agreement, the Note Purchase Agreement, the
Deposit Agreement, the Registration Rights Agreement or any Liquidity Facility
in form satisfactory to the Trustee, for any of the following purposes:

            (1) to evidence the succession of another corporation to the Company
      and the assumption by any such successor of the covenants of the Company
      herein contained or of the Company's obligations under the Note Purchase
      Agreement, the Registration Rights Agreement or any Liquidity Facility; or

            (2) to add to the covenants of the Company for the benefit of the
      Certificateholders, or to surrender any right or power conferred upon the
      Company in this Agreement, the Note Purchase Agreement, the Registration
      Rights Agreement or any Liquidity Facility; or

            (3) to correct or supplement any provision in this Agreement, the
      Intercreditor Agreement, the Escrow Agreement, the Deposit Agreement, the
      Note Purchase Agreement, the Registration Rights Agreement or any
      Liquidity Facility which may be defective or inconsistent with any other
      provision herein or therein or to cure any
<PAGE>   54
                                      -49-

      ambiguity or correct any mistake or to modify any other provision with
      respect to matters or questions arising under this Agreement, the Escrow
      Agreement, the Deposit Agreement, the Note Purchase Agreement, the
      Intercreditor Agreement, the Registration Rights Agreement or any
      Liquidity Facility, provided that any such action shall not materially
      adversely affect the interests of the Certificateholders; or

            (4) to comply with any requirement of the SEC, any applicable law,
      rules or regulations of any exchange or quotation system on which the
      Certificates are listed, any regulatory body or the Registration Rights
      Agreement to effectuate the Exchange Offer; or

            (5) to modify, eliminate or add to the provisions of this Agreement
      to such extent as shall be necessary to continue the qualification of this
      Agreement (including any supplemental agreement) under the Trust Indenture
      Act or under any similar Federal statute hereafter enacted, and to add to
      this Agreement such other provisions as may be expressly permitted by the
      Trust Indenture Act, excluding, however, the provisions referred to in
      Section 316(a)(2) of the Trust Indenture Act as in effect at the date as
      of which this instrument was executed or any corresponding provision in
      any similar Federal statute hereafter enacted; or

            (6) to evidence and provide for the acceptance of appointment under
      this Agreement by the Trustee of a successor Trustee and to add to or
      change any of the provisions of this Agreement as shall be necessary to
      provide for or facilitate the administration of the Trust, pursuant to the
      requirements of Section 7.10; or

            (7) to provide the information required under Section 7.12 and
      Section 12.03 as to the Trustee; or

            (8) to modify or eliminate provisions relating to the transfer or
      exchange of Exchange Certificates or the Initial Certificates upon
      consummation of the Exchange Offer (as defined in the Registration Rights
      Agreement) or effectiveness of the Shelf Registration Statement or the
      Exchange Offer Registration Statement;

provided, however, that no such supplemental agreement shall adversely affect
the status of any Trust as a grantor trust under Subpart E, Part I of Subchapter
J of Chapter 1 of Subtitle A of the Internal Revenue Code of 1986, as amended,
for U.S. federal income tax purposes.

            Section 9.02. Supplemental Agreements with Consent of
Certificateholders. With the consent of the Certificateholders holding
Certificates (including consents obtained in connection with a tender offer or
exchange offer for the Certificates) evidencing Fractional Undivided Interests
aggregating not less than a majority in interest in the Trust, by Direction of
said Certificateholders delivered to the Company and the Trustee, the Company
may (with the consent of the Owner Trustees, if any, which consent shall not be
unreasonably withheld), and the Trustee (subject to Section 9.03) shall, enter
into an agreement or agreements for the purpose of adding any provisions to or
changing in any manner or eliminating any of the provisions of this Agreement,
the Intercreditor Agreement, any Liquidity Facility, the Registration Rights
Agreement, the Escrow Agreement, the Deposit Agreement or the Note Purchase
Agreement to
<PAGE>   55
                                      -50-

the extent applicable to such Certificateholders or of modifying in any manner
the rights and obligations of such Certificateholders under this Agreement, the
Intercreditor Agreement, any Liquidity Facility, the Registration Rights
Agreement, the Escrow Agreement, the Deposit Agreement or the Note Purchase
Agreement; provided, however, that no such agreement shall, without the consent
of the Certificateholder of each Outstanding Certificate affected thereby:

            (1) reduce in any manner the amount of, or delay the timing of, any
      receipt by the Trustee (or, with respect to the Deposits, the
      Certificateholders) of payments on the Equipment Notes held in the Trust
      or on the Deposits or distributions that are required to be made herein on
      any Certificate, or change any date of payment on any Certificate, or
      change the place of payment where, or the coin or currency in which, any
      Certificate is payable, or impair the right to institute suit for the
      enforcement of any such payment or distribution on or after the Regular
      Distribution Date or Special Distribution Date applicable thereto; or

            (2) permit the disposition of any Equipment Note included in the
      Trust Property except as permitted by this Agreement, or otherwise deprive
      such Certificateholder of the benefit of the ownership of the Equipment
      Notes in the Trust; or

            (3) reduce the specified percentage of the aggregate Fractional
      Undivided Interests of the Trust which is required for any such
      supplemental agreement, or reduce such specified percentage required for
      any waiver of compliance with certain provisions of this Agreement or
      certain defaults hereunder and their consequences provided for in this
      Agreement; or

            (4) waive, amend or modify Section 2.4, 3.2 or 3.3 of the
      Intercreditor Agreement in a manner adverse to the Certificateholders; or

            (5) modify any of the provisions of this Section 9.02 or Section
      6.05, except to increase any such percentage or to provide that certain
      other provisions of this Agreement cannot be modified or waived without
      the consent of the Certificateholder of each Certificate affected thereby;
      or

            (6) adversely affect the status of any Trust as a grantor trust
      under Subpart E, Part I of Subchapter J of Chapter 1 of Subtitle A of the
      Internal Revenue Code of 1986, as amended, for U.S. federal income tax
      purposes.

            It shall not be necessary for any Direction of Certificateholders
under this Section to approve the particular form of any proposed supplemental
agreement, but it shall be sufficient if such Direction shall approve the
substance thereof.

            Section 9.03. Documents Affecting Immunity or Indemnity. If in the
opinion of the Trustee any document required to be executed by it pursuant to
the terms of Section 9.01 or 9.02 affects any interest, right, duty, immunity or
indemnity in favor of the Trustee under this Agreement, the Trustee may in its
discretion decline to execute such document.

            Section 9.04. Execution of Supplemental Agreements. In executing, or
accepting the additional trusts created by, any agreement permitted by this
Article or the
<PAGE>   56
                                      -51-

modifications thereby of the trusts created by this Agreement, the Trustee shall
be entitled to receive, and shall be fully protected in relying upon, an Opinion
of Counsel stating that the execution of such supplemental agreement is
authorized or permitted by this Agreement.

            Section 9.05. Effect of Supplemental Agreements. Upon the execution
of any agreement supplemental to this Agreement under this Article, this
Agreement shall be modified in accordance therewith, and such supplemental
agreement shall form a part of this Agreement for all purposes; and every Holder
of a Certificate theretofore or thereafter authenticated and delivered hereunder
shall be bound thereby.

            Section 9.06. Conformity with Trust Indenture Act. Every
supplemental agreement executed pursuant to this Article shall conform to the
requirements of the Trust Indenture Act as then in effect.

            Section 9.07. Reference in Certificates to Supplemental Agreements.
Certificates authenticated and delivered after the execution of any supplemental
agreement pursuant to this Article may bear a notation in form approved by the
Trustee as to any matter provided for in such supplemental agreement; and, in
such case, suitable notation may be made upon Outstanding Certificates after
proper presentation and demand.


                                    ARTICLE X

               AMENDMENTS TO INDENTURES AND FINANCING DOCUMENTS

            Section 10.01. Amendments and Supplements to Indentures and
Financing Documents. In the event that the Trustee, as holder (or beneficial
owner through the Subordination Agent) of any Equipment Note in trust for the
benefit of the Certificateholders or as Controlling Party under the
Intercreditor Agreement, receives (directly or indirectly through the
Subordination Agent) a request for a consent to any amendment, modification,
waiver or supplement under any Indenture, any other Financing Document, any
Equipment Note or any other related document, the Trustee shall forthwith send a
notice of such proposed amendment, modification, waiver or supplement to each
Certificateholder registered on the Register as of the date of such notice. The
Trustee shall request from the Certificateholders a Direction as to (a) whether
or not to take or refrain from taking (or direct the Subordination Agent to take
or refrain from taking) any action which a holder of such Equipment Note has the
option to direct, (b) whether or not to give or execute (or direct the
Subordination Agent to give or execute) any waivers, consents, amendments,
modifications or supplements as a holder of such Equipment Note or a Controlling
Party and (c) how to vote (or direct the Subordination Agent to vote) any
Equipment Note if a vote has been called for with respect thereto. Provided such
a request for Certificateholder Direction shall have been made, in directing any
action or casting any vote or giving any consent as the holder of any Equipment
Note (or in directing the Subordination Agent in any of the foregoing), (i)
other than as Controlling Party, the Trustee shall vote for or give consent to
any such action with respect to such Equipment Note in the same proportion as
that of (A) the aggregate face amounts of all Certificates actually voted in
favor of or for giving consent to such action by such Direction of
Certificateholders to (B) the aggregate face amount of all Outstanding
Certificates and (ii) as Controlling Party, the Trustee shall vote as directed
in such Certificateholder Direction by the Certificateholders evidencing a
Fractional Undivided Interest
<PAGE>   57
                                      -52-

aggregating not less than a majority in interest in the Trust. For purposes of
the immediately preceding sentence, a Certificate shall have been "actually
voted" if the Holder of such Certificate has delivered to the Trustee an
instrument evidencing such Holder's consent to such Direction prior to two
Business Days before the Trustee directs such action or casts such vote or gives
such consent. Notwithstanding the foregoing, but subject to Section 6.04 and the
Intercreditor Agreement, the Trustee may, in its own discretion and at its own
direction, consent and notify the relevant Loan Trustee of such consent (or
direct the Subordination Agent to consent and notify the Loan Trustee of such
consent) to any amendment, modification, waiver or supplement under the relevant
Indenture, any other Financing Document, any Equipment Note or any other related
document, if an Event of Default hereunder shall have occurred and be
continuing, or if such amendment, modification, waiver or supplement will not
materially adversely affect the interests of the Certificateholders.


                                   ARTICLE XI

                              TERMINATION OF TRUST

            Section 11.01. Termination of the Trust. The respective obligations
and responsibilities of the Company and the Trustee with respect to the Trust
shall terminate upon the distribution to all Holders of Certificates and the
Trustee of all amounts required to be distributed to them pursuant to this
Agreement and the disposition of all property held as part of the Trust
Property; provided, however, that in no event shall the Trust continue beyond
one hundred ten (110) years following the date of the earliest execution of this
Trust Agreement.

            Notice of any termination, specifying the Distribution Date upon
which the Certificateholders may surrender their Certificates to the Trustee for
payment of the final Distribution Date and cancellation, shall be mailed
promptly by the Trustee to Certificateholders not earlier than the 60th day and
not later than the 20th day next preceding such final Distribution Date
specifying (A) the Distribution Date upon which the proposed final payment of
the Certificates will be made upon presentation and surrender of Certificates at
the office or agency of the Trustee therein specified, (B) the amount of any
such proposed final payment, and (C) that the Record Date otherwise applicable
to such Distribution Date is not applicable, payments being made only upon
presentation and surrender of the Certificates at the office or agency of the
Trustee therein specified. The Trustee shall give such notice to the Registrar
at the time such notice is given to Certificateholders. Upon presentation and
surrender of the Certificates in accordance with such notice, the Trustee shall
cause to be distributed to Certificateholders such final payments.

            In the event that all of the Certificateholders shall not surrender
their Certificates for cancellation within six months after the date specified
in the above-mentioned written notice, the Trustee shall give a second written
notice to the remaining Certificateholders to surrender their Certificates for
cancellation and receive the final distribution with respect thereto. No
additional interest shall accrue on the Certificates after the Distribution Date
specified in the first written notice. In the event that any money held by the
Trustee for the payment of distributions on the Certificates shall remain
unclaimed for two years (or such lesser time as the Trustee shall be satisfied,
after sixty days' notice from the Company, is one month prior to the escheat
period provided under applicable law) after the final distribution date with
respect thereto, the Trustee
<PAGE>   58
                                      -53-

shall pay to each Loan Trustee the appropriate amount of money relating to such
Loan Trustee and shall give written notice thereof to the related Owner
Trustees, the Owner Participants and the Company.


                                   ARTICLE XII

                            MISCELLANEOUS PROVISIONS

            Section 12.01. Limitation on Rights of Certificateholders. The death
or incapacity of any Certificateholder shall not operate to terminate this
Agreement or the Trust, nor entitle such Certificateholder's legal
representatives or heirs to claim an accounting or to take any action or
commence any proceeding in any court for a partition or winding up of the Trust,
nor otherwise affect the rights, obligations, and liabilities of the parties
hereto or any of them.

            Section 12.02. Certificates Nonassessable and Fully Paid. Except as
set forth in the last sentence of this Section 12.02, Certificateholders shall
not be personally liable for obligations of the Trust, the Fractional Undivided
Interests represented by the Certificates shall be nonassessable for any losses
or expenses of the Trust or for any reason whatsoever, and Certificates, upon
authentication thereof by the Trustee pursuant to Section 3.03, are and shall be
deemed fully paid. No Certificateholder shall have any right (except as
expressly provided herein) to vote or in any manner otherwise control the
operation and management of the Trust Property, the Trust, or the obligations of
the parties hereto, nor shall anything set forth herein, or contained in the
terms of the Certificates, be construed so as to constitute the
Certificateholders from time to time as partners or members of an association.
Neither the existence of the Trust nor any provision herein is intended to or
shall limit the liability the Certificateholders would otherwise incur if the
Certificateholders owned Trust Property as co-owners, or incurred any
obligations of the Trust, directly rather than through the Trust.

            Section 12.03. Notices. (a) Unless otherwise specifically provided
herein, all notices required under the terms and provisions of this Agreement
shall be in English and in writing, and any such notice may be given by United
States mail, courier service or telecopy, and any such notice shall be effective
when received or, if made, given, furnished or filed by facsimile or
telecommunication transmission, when received unless received outside of
business hours, in which case on the next open of business on a Business Day,

            if to the Company, to:

                  America West Airlines, Inc.
                  4000 East Sky Harbor Boulevard
                  Phoenix, Arizona  85043

                  Attention:  Vice President-
                              Treasurer
                  Facsimile:  (602) 693-5886


            if to the Trustee, to:
<PAGE>   59
                                      -54-

                  Wilmington Trust Company
                  Rodney Square North
                  1100 North Market Street
                  Wilmington, Delaware  19890-0001

                      Attention: Corporate Trust Department
                            Facsimile: (302) 651-8882
                            Telephone: (302) 651-8584

            (b) The Company or the Trustee, by notice to the other, may
designate additional or different addresses for subsequent notices or
communications.

            (c) Any notice or communication to Certificateholders shall be
mailed by first-class mail to the addresses for Certificateholders shown on the
Register kept by the Registrar. Failure so to mail a notice or communication or
any defect in such notice or communication shall not affect its sufficiency with
respect to other Certificateholders.

            (d) If a notice or communication is mailed in the manner provided
above within the time prescribed, it is conclusively presumed to have been duly
given, whether or not the addressee receives it.

            (e) If the Company mails a notice or communication to the
Certificateholders, it shall mail a copy to the Trustee and to the Paying Agent
at the same time.

            (f) Notwithstanding the foregoing, all communications or notices to
the Trustee shall be deemed to be given only when received by a Responsible
Officer of the Trustee.

            (g) The Trustee shall promptly furnish the Company with a copy of
any demand, notice or written communication received by the Trustee hereunder
from any Certificateholder, Owner Trustee or Loan Trustee.

            Section 12.04. Governing Law. THIS AGREEMENT HAS BEEN DELIVERED IN
THE STATE OF NEW YORK AND THIS AGREEMENT AND THE CERTIFICATES SHALL BE GOVERNED
BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK AND THE
OBLIGATIONS, RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER SHALL BE DETERMINED IN
ACCORDANCE WITH SUCH LAWS.

            Section 12.05. Severability of Provisions. If any one or more of the
covenants, agreements, provisions or terms of this Agreement shall be for any
reason whatsoever held invalid, then such covenants, agreements, provisions, or
terms shall be deemed severable from the remaining covenants, agreements,
provisions or terms of this Agreement and shall in no way affect the validity or
enforceability of the other provisions of this Agreement or the Trust, or of the
Certificates or the rights of the Certificateholders thereof.

            Section 12.06. Trust Indenture Act Controls. Upon the occurrence of
any Registration Event, this Agreement shall become subject to the provisions of
the Trust Indenture Act and shall, to the extent applicable, be governed by such
provisions. From and after any
<PAGE>   60
                                      -55-

Registration Event, if any provision of this Agreement limits, qualifies or
conflicts with another provision which is required to be included in this
Agreement by the Trust Indenture Act, the required provision shall control.

            Section 12.07. Effect of Headings and Table of Contents. The Article
and Section headings herein and the Table of Contents are for convenience only
and shall not affect the construction hereof.

            Section 12.08. Successors and Assigns. All covenants, agreements,
representations and warranties in this Agreement by the Trustee and the Company
shall bind and, to the extent permitted hereby, shall inure to the benefit of
and be enforceable by their respective successors and assigns, whether so
expressed or not.

            Section 12.09. Benefits of Agreement. Nothing in this Agreement or
in the Certificates, express or implied, shall give to any Person, other than
the parties hereto and their successors hereunder, and the Certificateholders,
any benefit or any legal or equitable right, remedy or claim under this
Agreement.

            Section 12.10. Legal Holidays. In any case where any Regular
Distribution Date or Special Distribution Date relating to any Certificate shall
not be a Business Day, then (notwithstanding any other provision of this
Agreement) payment need not be made on such date, but may be made on the next
succeeding Business Day with the same force and effect as if made on such
Regular Distribution Date or Special Distribution Date, and no interest shall
accrue during the intervening period.

            Section 12.11. Counterparts. For the purpose of facilitating the
execution of this Agreement and for other purposes, this Agreement may be
executed simultaneously in any number of counterparts, each of which
counterparts shall be deemed to be an original, and all of which counterparts
shall constitute but one and the same instrument.

            Section 12.12. Intention of Parties. The parties hereto intend that
the Trust be classified for U.S. federal income tax purposes as a grantor trust
under Subpart E, Part I of Subchapter J of the Internal Revenue Code of 1986, as
amended, and not as a trust or association taxable as a corporation or as a
partnership. Each Certificateholder and Investor, by its acceptance of its
Certificate or a beneficial interest therein, agrees to treat the Trust as a
grantor trust for all U.S. federal, state and local income tax purposes. The
powers granted and obligations undertaken pursuant to this Agreement shall be so
construed so as to further such intent.
<PAGE>   61
                                      -56-

            IN WITNESS WHEREOF, the parties have caused this Agreement to be
duly executed by their respective officers thereunto duly authorized as of the
day and year first written above.

                                    AMERICA WEST AIRLINES, INC.

                                    By: /s/ W. Douglas Parker
                                       --------------------------------     
                                          Name: W. Douglas Parker
                                          Title: Sr. Vice President & CFO


                                    WILMINGTON TRUST COMPANY,
                                      as Trustee

                                    By: /s/ Jill K. Morrison
                                        --------------------------------
                                          Name: Jill K. Morrison
                                          Title: Administrative Account
                                                 Manager

<PAGE>   62
                                                                       EXHIBIT A

            FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION WITH
              TRANSFERS OF CERTIFICATES PURSUANT TO REGULATION S 

                                                    [date]

Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE 19890-0001

Attention:  Corporate Trust Trustee Administration

      Re:   America West Airlines Pass Through Trust, Series 1998-1B-S
            (the "Trust") America West Airlines Pass Through Certificates,
            Series 1998-1B-S (the "Certificates") 
                                                     

Sirs:

            In connection with our proposed sale of $_____ Fractional Undivided
Interest of the Certificates, we confirm that such sale has been effected
pursuant to and in accordance with Regulation S under the Securities Act of
1933, as amended, and, accordingly, we represent that:

            (1) the offer of the Certificates was not made to a person in the
      United States or to or for the account or benefit of a U.S. person;

            (2) either (a) at the time the buy order was originated, the
      transferee was outside the United States or we and any person acting on
      our behalf reasonably believed that the transferee was outside the United
      States or (b) the transaction was executed in, on or through the
      facilities of a designated off-shore securities market and neither we nor
      any person acting on our behalf knows that the transaction has been
      pre-arranged with a buyer in the United States;

            (3) no directed selling efforts have been made in the United States
      in contravention of the requirements of Rule 903(a) or Rule 904(a) of
      Regulation S, as applicable; and

            (4) the transaction is not part of a plan or scheme to evade the
      registration requirements of the Securities Act.

            In addition, if the sale is made during a restricted period and the
provisions of Rule 903(b)(2) or Rule 904(b)(1) of Regulation S are applicable
thereto, we confirm that such sale has been made in accordance with the
applicable provisions of Rule 903(b)(2) or Rule 904(b)(1), as the case may be.

            You and America West Airlines, Inc. are entitled to rely upon this
letter and are irrevocably authorized to produce this letter or a copy hereof to
any interested party in any
<PAGE>   63
                                      A-2

administrative or legal proceedings or official inquiry with respect to the
matters covered hereby. Terms used in this certificate have the meanings set
forth in Regulation S.

                                       Very truly yours,



                                       [Name of Transferor]
<PAGE>   64
                                                                       EXHIBIT B

              FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION
                        WITH TRANSFERS OF CERTIFICATES TO
                  NON-QIB INSTITUTIONAL ACCREDITED INVESTORS

                                                [date]

Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE 19890-0001


Attention:  Corporate Trust Trustee Administration

America West Airlines, Inc.
4000 East Sky Harbor Boulevard
Phoenix, Arizona 85043

                              AMERICA WEST AIRLINES
               PASS THROUGH TRUST, SERIES 1998-1B-S (the "Trust")
                   Pass Through Certificates, Series 1998-1B-S
                              (the "Certificates")


Ladies and Gentlemen:

            In connection with our proposed purchase of U.S. $[_____________]
Fractional Undivided Interest of Certificates, we confirm that:

            1. We understand that any subsequent transfer of the Certificates is
subject to certain restrictions and conditions set forth in the Pass Through
Trust Agreement, dated as of October 6, 1998, between America West Airlines,
Inc. (the "Company") and Wilmington Trust Company (the "Trustee") relating to
the Certificates, and we agree to be bound by, and not to resell, pledge or
otherwise transfer the Certificates except in compliance with, such restrictions
and conditions and the Securities Act of 1933, as amended (the "Securities
Act").

            2. We are purchasing Certificates having an aggregate principal
amount of not less than $100,000 and each account (if any) for which we are
purchasing Certificates is purchasing Certificates having an aggregate principal
amount of not less than $100,000.

            3. We understand that the Certificates have not been registered
under the Securities Act, that the Certificates are being sold to us in a
transaction that is exempt from the registration requirements of the Securities
Act and that the Certificates may not be offered or resold except as permitted
in the following sentence. We agree, on our own behalf and on behalf of any
accounts for which we are acting as hereinafter stated, that, if we should sell
any Certificates within three years after the later of the original issuance of
such Certificate and the
<PAGE>   65
                                      B-2

last date on which such Certificate is owned by the Company, the Trustee or any
affiliate of any of such persons, we will do so only (A) to the Company, (B) in
accordance with Rule 144A under the Securities Act to a "qualified institutional
buyer" (as defined therein), (C) outside the United States in accordance with
Rule 904 of Regulation S under the Securities Act, (D) pursuant to the exemption
from registration provided by Rule 144 under the Securities Act or (E) pursuant
to an effective registration statement under the Securities Act, and we further
agree to provide to any person purchasing any of the Certificates from us a
notice advising such purchaser that resales of the Certificates are restricted
as stated herein.

            4. We understand that, on any proposed resale of any Certificates,
we will be required to furnish to the Company and the Trustee such
certifications, legal opinions and other information as the Trustee may
reasonably require to confirm that the proposed sale complies with the foregoing
restrictions. We further understand that the Certificates purchased by us will
bear a legend to the foregoing effect.

            5. We are an institutional "accredited investor" (as defined in Rule
501(a)(1), (2), (3) or (7) of Regulation D under the Securities Act) and have
such knowledge and experience in financial and business matters as to be capable
of evaluating the merits and risks of our investment in the Certificates, and we
and any accounts for which we are acting are each able to bear the economic risk
of our or their investments.

            6. We are acquiring the Certificates purchased by us for our own
account or for one or more accounts (each of which is an institutional
"accredited investor") as to each of which we exercise sole investment
discretion and not with a view to any distribution of the Certificates, subject,
nevertheless to the understanding that the disposition of our property shall at
all times be and remain within our control.

            You are entitled to rely upon this letter and are irrevocably
authorized to produce this letter or a copy thereof to any interested party in
any administrative or legal proceedings or official inquiry with respect to the
matters covered hereby.

                                Very truly yours,


                                 By:_____________________________
                                      Name:
                                     Title:

<PAGE>   1
                                                                     Exhibit 4.8
- --------------------------------------------------------------------------------




                          PASS THROUGH TRUST AGREEMENT

                           Dated as of October 6, 1998

                                     between

                           AMERICA WEST AIRLINES, INC.

                                       and

                            WILMINGTON TRUST COMPANY,

                                   as Trustee

           America West Airlines Pass Through Trust, Series 1998-1C-O

            7.84% Initial Pass Through Certificates, Series 1998-1C-O
           7.84% Exchange Pass Through Certificates, Series 1998-1C-O




- --------------------------------------------------------------------------------
<PAGE>   2
Reconciliation and tie between America West Airlines Pass Through Trust
Agreement, Series 1998-1C-O dated as of October 6, 1998, and the Trust Indenture
Act of 1939. This reconciliation does not constitute part of the Pass Through
Trust Agreement.

<TABLE>
<CAPTION>
        Trust Indenture Act                       Pass Through Trust
         of 1939 Section                          Agreement Section
         ---------------                          -----------------
<S>                                               <C>
            310(a)(1)                                   7.08
               (a)(2)                                   7.08
            312(a)                                      3.05; 8.01; 8.02
            313(a)                                      7.06; 8.03
            314(a)                                      8.04(a),(c) & (d)
            (a)(4)                                      8.04(e)
            (c)(1)                                      1.02
            (c)(2)                                      1.02
            (d)(1)                                      7.13; 11.01
            (d)(2)                                      7.13; 11.01
            (d)(3)                                      2.01
            (e)                                         1.02
            315(b)                                      7.02
            316(a)(last sentence)                       1.04(c)
               (a)(1)(A)                                6.04
               (a)(1)(B)                                6.05
               (b)                                      6.06
               (c)                                      1.04(e)
            317(a)(1)                                   6.03
               (b)                                      7.13
            318(a)                                      12.06
</TABLE>
<PAGE>   3
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
SECTION                                                                                              PAGE
<S>                                                                                                  <C>
ARTICLE I  DEFINITIONS ...........................................................................      2
      Section 1.01.  Definitions .................................................................      2
      Section 1.02.  Compliance Certificates and Opinions ........................................     13
      Section 1.03.  Form of Documents Delivered to Trustee ......................................     14
      Section 1.04.  Directions of Certificateholders ............................................     14

ARTICLE II  ORIGINAL ISSUANCE OF CERTIFICATES; ACQUISITION OF EQUIPMENT
            NOTES  ...............................................................................     16
      Section 2.01.  Issuance of Certificates; Acquisition of Equipment Notes ....................     16
      Section 2.02.  Withdrawal of Deposits ......................................................     17
      Section 2.03.  Acceptance by Trustee .......................................................     17
      Section 2.04.  Limitation of Powers ........................................................     17

ARTICLE III  THE CERTIFICATES ....................................................................     17
      Section 3.01.  Title, Form, Denomination and Execution of Certificates .....................     17
      Section 3.02.  Restrictive Legends .........................................................     19
      Section 3.03.  Authentication of Certificates ..............................................     21
      Section 3.04.  Transfer and Exchange .......................................................     21
      Section 3.05.  Book-Entry Provisions for Restricted Global Certificates and
                     Regulation S Global Certificates.-...........................................     22
      Section 3.06.  Special Transfer Provisions .................................................     24
      Section 3.07.  Mutilated, Destroyed, Lost or Stolen Certificates ...........................     27
      Section 3.08.  Persons Deemed Owners .......................................................     27
      Section 3.09.  Cancellation ................................................................     27
      Section 3.10.  Temporary Certificates ......................................................     27
      Section 3.11.  Limitation of Liability for Payments ........................................     28
      Section 3.12.  ERISA Restrictive Legend ....................................................     28

ARTICLE IV  DISTRIBUTIONS; STATEMENTS TO CERTIFICATEHOLDERS ......................................     29
      Section 4.01.  Certificate Account and Special Payments Account ............................     29
      Section 4.02.  Distributions from Certificate Account and Special Payments Account .........     29
      Section 4.03.  Statements to Certificateholders ............................................     30
      Section 4.04.  Investment of Special Payment Moneys ........................................     32

ARTICLE V  THE COMPANY ...........................................................................     32
      Section 5.01.  Maintenance of Corporate Existence ..........................................     32
      Section 5.02.  Consolidation, Merger, etc ..................................................     32

ARTICLE VI  DEFAULT...............................................................................     33
      Section 6.01.  Events of Default ...........................................................     33
      Section 6.02.  Incidents of Sale of Equipment Notes ........................................     35
      Section 6.03.  Judicial Proceedings Instituted by Trustee; Trustee May Bring Suit ..........     35
</TABLE>
<PAGE>   4
<TABLE>
<CAPTION>
SECTION                                                                                                PAGE
<S>                                                                                                    <C>
      Section 6.04.  Control by Certificateholders .................................................     36
      Section 6.05.  Waiver of Past Defaults .......................................................     36
      Section 6.06.  Right of Certificateholders to Receive Payments Not to Be Impaired ............     37
      Section 6.07.  Certificateholders May Not Bring Suit Except Under Certain Conditions .........     37
      Section 6.08.  Remedies Cumulative ...........................................................     37

ARTICLE VII  THE TRUSTEE ...........................................................................     38
      Section 7.01.  Certain Duties and Responsibilities ...........................................     38
      Section 7.02.  Notice of Defaults ............................................................     38
      Section 7.03.  Certain Rights of Trustee .....................................................     38
      Section 7.04.  Not Responsible for Recitals or Issuance of Certificates ......................     40
      Section 7.05.  May Hold Certificates .........................................................     40
      Section 7.06.  Money Held in Trust ...........................................................     40
      Section 7.07.  Compensation and Reimbursement ................................................     40
      Section 7.08.  Corporate Trustee Required; Eligibility .......................................     41
      Section 7.09.  Resignation and Removal; Appointment of Successor .............................     42
      Section 7.10.  Acceptance of Appointment by Successor ........................................     43
      Section 7.11.  Merger, Conversion, Consolidation or Succession to Business ...................     43
      Section 7.12.  Maintenance of Agencies .......................................................     44
      Section 7.13.  Money for Certificate Payments to Be Held in Trust ............................     45
      Section 7.14.  Registration of Equipment Notes in Name of Subordination Agent ................     45
      Section 7.15.  Representations and Warranties of Trustee .....................................     45
      Section 7.16.  Withholding Taxes, Information Reporting ......................................     46
      Section 7.17.  Trustee's Liens ...............................................................     47
      Section 7.18.  Preferential Collection of Claims .............................................     47

ARTICLE VIII  CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE .....................................     47
      Section 8.01.  The Company to Furnish Trustee with Names and Addresses of Certificateholders..     47
      Section 8.02.  Preservation of Information; Communications to Certificateholders .............     48
      Section 8.03.  Reports by Trustee ............................................................     48
      Section 8.04.  Reports by the Company ........................................................     48

ARTICLE IX  SUPPLEMENTAL AGREEMENTS ................................................................     49
      Section 9.01.  Supplemental Agreements Without Consent of Certificateholders .................     49
      Section 9.02.  Supplemental Agreements with Consent of Certificateholders ....................     50
      Section 9.03.  Documents Affecting Immunity or Indemnity .....................................     51
      Section 9.04.  Execution of Supplemental Agreements ..........................................     51
      Section 9.05.  Effect of Supplemental Agreements .............................................     52
      Section 9.06.  Conformity with Trust Indenture Act ...........................................     52
      Section 9.07.  Reference in Certificates to Supplemental Agreements ..........................     52
</TABLE>


                                       ii
<PAGE>   5
<TABLE>
<CAPTION>
SECTION                                                                                              PAGE
<S>                                                                                                  <C>
ARTICLE X  AMENDMENTS TO INDENTURES AND FINANCING DOCUMENTS ......................................     52
      Section 10.01.  Amendments and Supplements to Indentures and Financing Documents ...........     52

ARTICLE XI  TERMINATION OF TRUST .................................................................     53
      Section 11.01.  Termination of the Trust ...................................................     53

ARTICLE XII  MISCELLANEOUS PROVISIONS ............................................................     55
      Section 12.01.  Limitation on Rights of Certificateholders .................................     55
      Section 12.02.  Certificates Nonassessable and Fully Paid ..................................     55
      Section 12.03.  Notices ....................................................................     56
      Section 12.04.  Governing Law ..............................................................     57
      Section 12.05.  Severability of Provisions .................................................     57
      Section 12.06.  Trust Indenture Act Controls ...............................................     57
      Section 12.07.  Effect of Headings and Table of Contents ...................................     57
      Section 12.08.  Successors and Assigns .....................................................     57
      Section 12.09.  Benefits of Agreement ......................................................     57
      Section 12.10.  Legal Holidays .............................................................     57
      Section 12.11.  Counterparts ...............................................................     57
      Section 12.12.  Intention of Parties .......................................................     58
</TABLE>


Exhibit A     -   Form of Certificate
Exhibit B     -   Form of Certificate to Request Removal of Restricted Legend
Exhibit C     -   Form of Certificate to be Delivered by an Institutional
                  Accredited Investor
Exhibit D     -   Form of Assignment and Assumption Agreement
Exhibit E     -   Form of Notice to Withholding Agent


                                      iii
<PAGE>   6
                          PASS THROUGH TRUST AGREEMENT


            This PASS THROUGH TRUST AGREEMENT, dated as of October 6, 1998 (the
"Agreement"), between AMERICA WEST AIRLINES, INC., a Delaware corporation, and
WILMINGTON TRUST COMPANY, as Trustee, is made with respect to the formation of
America West Airlines Pass Through Trust, Series 1998-1C-O and the issuance of
7.84% America West Airlines Pass Through Trust, Series 1998-1C-O Pass Through
Certificates representing fractional undivided interests in the Trust.

                                   WITNESSETH:

            WHEREAS, the Company has obtained commitments from AVSA for the
delivery of certain Aircraft;

            WHEREAS, the Company intends to finance (or refinance) the
acquisition of the Aircraft either (i) through separate leveraged lease
transactions in which the Company will lease such aircraft (collectively, the
"Leased Aircraft") or (ii) through separate secured loan transactions in which
the Company will own such Aircraft (collectively, the "Owned Aircraft");

            WHEREAS, in the case of each Leased Aircraft, each Owner Trustee,
acting on behalf of the corresponding Owner Participant, will issue pursuant to
an Indenture, on a non-recourse basis, three series (or, subject to satisfaction
of certain preconditions contained in the Note Purchase Agreement, four) of
Equipment Notes in order to finance a portion of its purchase price of such
Leased Aircraft;

            WHEREAS, in the case of each Owned Aircraft, the Company will issue
pursuant to an Indenture, on a recourse basis, three (or, subject to
satisfaction of certain preconditions contained in the Note Purchase Agreement,
four) series of Equipment Notes to finance a portion of the purchase price of
such Owned Aircraft;

            WHEREAS, the Trustee, upon execution and delivery of this Agreement,
hereby declares the creation of the Trust for the benefit of the
Certificateholders, and the initial Certificateholders, as the grantors of the
Trust, by their respective acceptances of the Certificates, join in the creation
of this Trust with the Trustee;

            WHEREAS, all Certificates to be issued by the Trust will evidence
fractional undivided interests in the Trust and will convey no rights, benefits
or interests in respect of any property other than the Trust Property except for
those Certificates to which an Escrow Receipt has been affixed;

            WHEREAS, the Escrow Agent and the Initial Purchasers have
contemporaneously herewith entered into an Escrow Agreement with the Escrow
Paying Agent pursuant to which the Initial Purchasers have delivered to the
Escrow Agent the proceeds from the sale of the Certificates and have irrevocably
instructed the Escrow Agent to withdraw and pay funds from such proceeds upon
request and proper certification by the Trustee to purchase Equipment Notes;
<PAGE>   7
                                      -2-


            WHEREAS, the Escrow Agent on behalf of the Certificateholders has
contemporaneously herewith entered into a Deposit Agreement with the Depositary
under which the Deposits referred to therein will be made and from which it will
withdraw funds to allow the Trustee to purchase Equipment Notes from time to
time prior to the Delivery Period Termination Date;

            WHEREAS, pursuant to the terms and conditions of this Agreement and
the Note Purchase Agreement, upon or following delivery of an Aircraft, the
Trustee on behalf of the Trust, using funds withdrawn under the Escrow
Agreement, may purchase an Equipment Note having the same interest rate as, and
final legal distribution date not later than the final Regular Distribution Date
of, the Certificates issued hereunder and shall hold such Equipment Note in
trust for the benefit of the Certificateholders;

            WHEREAS, to facilitate the sale of Equipment Notes to, and the
purchase of Equipment Notes by, the Trustee on behalf of the Trust, the Company
has duly authorized the execution and delivery of this Agreement as the
"issuer", as such term is defined in and solely for purposes of the Securities
Act, of the Certificates to be issued pursuant hereto and as the "obligor", as
such term is defined in and solely for purposes of the Trust Indenture Act of
1939, as amended, with respect to all such Certificates and is undertaking to
perform certain administrative and ministerial duties hereunder and is also
undertaking to pay the ongoing fees and expenses of the Trustee;

            WHEREAS, all of the conditions and requirements necessary to make
this Agreement, when duly executed and delivered, a valid, binding and legal
instrument, enforceable in accordance with its terms and for the purposes herein
expressed, have been done, performed and fulfilled, and the execution and
delivery of this Agreement in the form and with the terms hereof have been in
all respects duly authorized; and

            WHEREAS, upon issuance of the Exchange Certificates, if any, or the
effectiveness of the Shelf Registration Statement, this Agreement, as amended or
supplemented from time to time, will be subject to the provisions of the Trust
Indenture Act of 1939, and shall, to the extent applicable, be governed by such
provisions;

            NOW, THEREFORE, in consideration of the mutual agreements herein
contained, and of other good and valuable consideration the receipt and adequacy
of which are hereby acknowledged, the parties hereto agree as follows:


                                    ARTICLE I

                                   DEFINITIONS

            Section 1.01. Definitions. For all purposes of this Agreement,
except as otherwise expressly provided or unless the context otherwise requires:

            (1) the terms used in this Agreement, including in the recitals to
      this Agreement, that are defined in this Article have the meanings
      assigned to them in this Article, and include the plural as well as the
      singular;
<PAGE>   8
                                      -3-


            (2) all other terms used herein which are defined in the Trust
      Indenture Act, either directly or by reference therein, or by the rules
      promulgated under the Trust Indenture Act, have the meanings assigned to
      them therein;

            (3) all references in this Agreement to designated "Articles",
      "Sections", "Subsections" and other subdivisions are to the designated
      Articles, Sections, Subsections and other subdivisions of this Agreement;

            (4) the words "herein", "hereof" and "hereunder" and other words of
      similar import refer to this Agreement as a whole and not to any
      particular Article, Section, SubSection or other subdivision; and

            (5) unless the context otherwise requires, whenever the words
      "including", "include" or "includes" are used herein, it shall be deemed
      to be followed by the phrase "without limitation".

            Affiliate: Means, with respect to any specified Person, any other
      Person directly or indirectly controlling or controlled by or under direct
      or indirect common control with such Person. For the purposes of this
      definition, "control" means the power, directly or indirectly, to direct
      the management and policies of such Person, whether through the ownership
      of voting securities or by contract or otherwise, and the terms
      "controlling" and "controlled" have meanings correlative to the foregoing.

            Agent Members:  Has the meaning specified in Section 3.05.

            Agreement:  Has the meaning specified in the initial paragraph
      hereto.

            Aircraft:  Has the meaning specified in the Note Purchase
      Agreement.

            Aircraft Purchase Agreement:  Has the meaning specified in the
      Note Purchase Agreement.

            Applicable Delivery Date:  Has the meaning specified in Section
      2.01(b).

            Applicable Participation Agreement:  Has the meaning specified in
      Section 2.01(b).

            Assignment and Assumption Agreement: Means the assignment and
      assumption agreement substantially in the form of Exhibit D hereto to be
      executed and delivered in accordance with Section 11.01.

            Authorized Agent:  Means any Paying Agent or Registrar for the
      Certificates.

            Avoidable Tax: Means a state or local tax (i) upon (w) the Trust,
      (x) the Trust Property, (y) Certificate-holders or (z) the Trustee for
      which the Trustee is entitled to seek reimbursement from the Trust
      Property, and (ii) which would be avoided if the Trustee were located in
      another state, or jurisdiction within a state, within the United
<PAGE>   9
                                      -4-


     States. A tax shall not be an Avoidable Tax if the Company or any Owner
     Trustee shall agree to pay, and shall pay, such tax.

            AVSA:  Means AVSA S.A.R.L., an affiliate of Airbus Industrie
      G.I.E.

            Business Day: Means any day other than a Saturday, a Sunday or a day
      on which commercial banks are required or authorized to close in Phoenix,
      Arizona, New York, New York, Wilmington, Delaware or, so long as any
      Certificate is outstanding, the city and state in which the Trustee or any
      Loan Trustee maintains its Corporate Trust Office or receives and
      disburses funds.

            Cedel:  Means Cedel Bank societe anonyme.

            Certificate:  Means any one of the Initial Certificates or
      Exchange Certificates and any such Certificates issued in exchange
      therefor or replacement thereof pursuant to this Agreement.

            Certificate Account:  Means the account or accounts created and
      maintained pursuant to Section 4.01(a).

            Certificate Purchase Agreement: Means the Purchase Agreement dated
      September 24, 1998 among the Initial Purchasers and the Company, as the
      same may be amended, supplemented or otherwise modified from time to time
      in accordance with its terms.

            Certificateholder or Holder:  Means the Person in whose name a
      Certificate is registered in the Register.

            Class D Certificateholder: Means, at any time, any holder of one or
      more pass through certificates issued by the America West Airlines Pass
      Through Trust, Series 1998-1D, if and when established.

            Company: Means America West Airlines, Inc., a Delaware corporation,
      or its successor in interest pursuant to Section 5.02, or (only in the
      context of provisions hereof, if any, where such reference is required for
      purposes of compliance with the Trust Indenture Act) any other "obligor"
      (within the meaning of the Trust Indenture Act) with respect to the
      Certificates.

          Controlling Party: Has the meaning specified in the Intercreditor
     Agreement.

          Corporate Trust Office: With respect to the Trustee or any Loan
     Trustee, means the office of such trustee in the city at which at any
     particular time its corporate trust business shall be principally
     administered.

            Cut-off Date:  Means the earlier of (a) the Delivery Period
      Termination Date and (b) the date on which a Triggering Event occurs.

            Definitive Certificates:  Has the meaning specified in Section
      3.01(e).
<PAGE>   10
                                      -5-


            Delivery Date:  Has the meaning specified in the Note Purchase
      Agreement.

            Delivery Notice:  Has the meaning specified in the Note Purchase
      Agreement.

            Delivery Period Termination Date: Means the earlier of (a) November
      30, 1999, or, if the Equipment Notes relating to all of the Aircraft (or
      Substitute Aircraft in lieu thereof) have not been purchased by the
      Trustee and the Other Trustees on or prior to such date due to any reason
      beyond the control of the Company and not occasioned by the Company's
      fault or negligence, January 31, 2000 and (b) the date on which Equipment
      Notes issued with respect to all of the Aircraft (or Substitute Aircraft
      in lieu thereof) have been purchased by the Trustee and the Other Trustees
      in accordance with the Note Purchase Agreement.

            Deposits:  Has the meaning specified in the Deposit Agreement.

            Deposit Agreement: Means the Deposit Agreement dated as of October
      6, 1998 relating to the Certificates between the Depositary and the Escrow
      Agent, as the same may be amended, supplemented or otherwise modified from
      time to time in accordance with its terms.

            Depositary: Means ABN AMRO Bank N.V., acting through its Chicago
      branch.

            Direction: Has the meaning specified in Section 1.04(a).

            Distribution Date:  Means any Regular Distribution Date or
      Special Distribution Date as the context requires.

            DTC: Means The Depository Trust Company, its nominees and their
      respective successors.

            EBO Date: Means the date set forth on Schedule 1 to the Lease as the
      "EBO Date".

            Equipment Notes:  Means the equipment notes issued under the
      Indentures.

            ERISA:  Means the Employee Retirement Income Security Act of
      1974, as amended from time to time, or any successor federal statute.

            ERISA Legend:  Has the meaning specified in Section 3.12.

            Escrow Agent:  Means, initially, Wilmington Trust Company.

            Escrow Agreement: Means the Escrow and Paying Agent Agreement dated
      as of October 6, 1998 relating to the Certificates, among the Escrow
      Agent, the Escrow Paying Agent, the Trustee and the Initial Purchasers, as
      the same may be amended, supplemented or otherwise modified from time to
      time in accordance with its terms.
<PAGE>   11
                                      -6-


            Escrow Paying Agent:  Means the Person acting as paying agent
      under the Escrow Agreement.

            Escrow Receipt:  Means the receipt substantially in the form
      annexed to the Escrow Agreement representing a fractional undivided
      interest in the funds held in escrow thereunder.

            Euroclear:  Means Morgan Guaranty Trust Company of New York,
      Brussels Office, as operator of the Euroclear System.

            Event of Default: Means an Indenture Default under any Indenture
      pursuant to which Equipment Notes held by the Trust were issued.

            Exchange Certificates: Means the pass through certificates
      substantially in the form of Exhibit A hereto issued in exchange for the
      Initial Certificates pursuant to the Registration Rights Agreement and
      authenticated hereunder.

            Exchange Offer:  Means the exchange offer which may be made
      pursuant to the Registration Rights Agreement to exchange Initial
      Certificates for Exchange Certificates.

            Exchange Offer Registration Statement: Means the registration
      statement that, pursuant to the Registration Rights Agreement, is filed by
      the Company with the SEC with respect to the exchange of Initial
      Certificates for Exchange Certificates.

            Final Legal Distribution Date:  Means January 2, 2012.

            Final Withdrawal:  Has the meaning specified in the Escrow
      Agreement.

            Final Withdrawal Date:  Has the meaning specified in the Escrow
      Agreement.

            Final Withdrawal Notice: Has the meaning specified in Section 2.02.

            Financing Documents: With respect to any Equipment Note, means (i)
      the Indenture and the Participation Agreement relating to such Equipment
      Note, and (ii) in the case of any Equipment Note related to a Leased
      Aircraft, the Lease relating to such Leased Aircraft.

            Fractional Undivided Interest:  Means the fractional undivided
      interest in the Trust that is evidenced by a Certificate.

            Global Certificates: Has the meaning specified in Section 3.01(d).

            Global Exchange Certificate: Has the meaning specified in Section
      3.01(f).

            Indenture: Means each of the separate trust indentures and mortgages
      relating to the Aircraft, each as specified or described in a Delivery
      Notice delivered pursuant to the Note Purchase Agreement or the related
      Participation Agreement, in each case as the
<PAGE>   12
                                      -7-


      same may be amended, supplemented or otherwise modified from time to time
      in accordance with its terms.

            Indenture Default: With respect to any Indenture, means any Event of
      Default (as such term is defined in such Indenture).

            Initial Certificates: Means the certificates issued and
      authenticated hereunder substantially in the form of Exhibit A hereto
      other than the Exchange Certificates.

            Initial Purchasers: Means, collectively, Morgan Stanley & Co.
      Incorporated, Donaldson, Lufkin & Jenrette Securities Corporation,
      Merrill, Lynch, Pierce, Fenner & Smith Incorporated and Salomon Smith
      Barney Inc.

            Institutional Accredited Investor: Means an institutional investor
      that is an "accredited investor" within the meaning set forth in Rule
      501(a)(1), (2), (3) or (7) of Regulation D under the Securities Act.

            Intercreditor Agreement: Means the Intercreditor Agreement dated as
      of October 6, 1998 among the Trustee, the Other Trustees, the Liquidity
      Provider, the liquidity provider relating to the Certificates issued under
      (and as defined in) each of the Other Pass Through Trust Agreements, and
      Wilmington Trust Company, as Subordination Agent and as trustee
      thereunder, as amended, supplemented or otherwise modified from time to
      time in accordance with its terms.

            Investors: Means the Initial Purchasers together with all subsequent
      beneficial owners of the Certificates.

            Issuance Date: Means the date of the issuance of the Initial
      Certificates.

            Lease: Means, with respect to each Leased Aircraft, the lease
      between an Owner Trustee, as the lessor, and the Company, as the lessee,
      referred to in the related Indenture, as such lease may be amended,
      supplemented or otherwise modified in accordance with its terms.

            Leased Aircraft:  Has the meaning specified in the second recital
      to this Agreement.

            Liquidity Facility: Means, initially, the Revolving Credit Agreement
      dated as of October 6, 1998 relating to the Certificates, between the
      Liquidity Provider and the Subordination Agent, as agent and trustee for
      the Trustee, and, from and after the replacement of such Agreement
      pursuant to the Intercreditor Agreement, the replacement liquidity
      facility therefor, in each case as amended, supplemented or otherwise
      modified from time to time in accordance with their respective terms.

            Liquidity Provider: Means, initially, ABN AMRO Bank N.V., acting
      through its Chicago branch and any replacement or successor therefor
      appointed in accordance with the Intercreditor Agreement.
<PAGE>   13
                                      -8-


            Loan Trustee: With respect to any Equipment Note or the Indenture
      applicable thereto, means the bank or trust company designated as trustee
      under such Indenture, together with any successor to such trustee
      appointed pursuant thereto.

            Material Adverse Tax Event:  Has the meaning specified in Section
      17.3(a)(4) of the Lease.

            Non-U.S. Person:  Means a Person that is not a "U.S. person", as
      defined in Regulation S.

            Note Purchase Agreement: Means the Note Purchase Agreement dated as
      of October 6, 1998 among the Trustee, the Other Trustees, the Company, the
      Escrow Agent, the Escrow Paying Agent and the Subordination Agent,
      providing for, among other things, the purchase of Equipment Notes by the
      Trustee on behalf of the Trust, as the same may be amended, supplemented
      or otherwise modified from time to time, in accordance with its terms.

            Notice of Purchase Withdrawal:  Has the meaning specified in the
      Deposit Agreement.

            Offering Circular: Means the Offering Memorandum dated September 24,
      1998 relating to the offering of the Certificates and the certificates
      issued under the Other Pass Through Trust Agreements.

            Officer's Certificate: Means a certificate signed, (a) in the case
      of the Company, by any Vice President or more senior officer of the
      Company or, (b) in the case of an Owner Trustee or a Loan Trustee, a
      Responsible Officer of such Owner Trustee or such Loan Trustee, as the
      case may be.

            Opinion of Counsel: Means a written opinion of legal counsel who (a)
      in the case of counsel for the Company may be (i) the General Counsel of
      the Company, (ii) Cooley Godward LLP, (iii) Vedder, Price, Kaufman,
      Kammholz & Day, or (iv) such other counsel designated by the Company and
      reasonably acceptable to the Trustee and (b) in the case of counsel for
      any Owner Trustee or any Loan Trustee may be such counsel as may be
      designated by any of them whether or not such counsel is an employee of
      any of them, and who shall be reasonably acceptable to the Trustee.

            Other Pass Through Trust Agreements:  Means each of the two other
      America West Airlines 1998-1 Pass Through Trust Agreements relating to
      America West Airlines Pass Through Trust, Series 1998-1A-O and America
      West Airlines Pass Through Trust, Series 1998-1B-O, dated the date
      hereof.

            Other Trustees:  Means the trustees under the Other Pass Through
      Trust Agreements, and any successor or other trustee appointed as
      provided therein.

            Other Trusts:  Means the America West Airlines Pass Through
      Trust, Series 1998-1A-O and America West Airlines Pass Through Trust,
      Series 1998-1B-O, created on the date hereof.
<PAGE>   14
                                      -9-


            Outstanding:  When used with respect to Certificates, means, as
      of the date of determination, all Certificates theretofore
      authenticated and delivered under this Agreement, except:

                  (i)  Certificates theretofore canceled by the Registrar or
            delivered to the Trustee or the Registrar for cancellation;

                  (ii) Certificates for which money in the full amount required
            to make the final distribution with respect to such Certificates
            pursuant to Section 11.01 hereof has been theretofore deposited with
            the Trustee in trust for the Holders of such Certificates as
            provided in Section 4.01 pending distribution of such money to such
            Certificateholders pursuant to payment of such final distribution;
            and

                  (iii) Certificates in exchange for or in lieu of which other
            Certificates have been authenticated and delivered pursuant to this
            Agreement.

            Owned Aircraft:  Has the meaning specified in the second recital
      to this Agreement.

            Owner Participant: With respect to any Equipment Note relating to a
      Leased Aircraft, means the "Owner Participant" as referred to in the
      Indenture pursuant to which such Equipment Note is issued and any
      permitted successor or assign of such Owner Participant; and Owner
      Participants at any time of determination means all of the Owner
      Participants thus referred to in the Indentures.

            Owner Trustee: With respect to any Equipment Note relating to a
      Leased Aircraft, means the "Owner Trustee", as referred to in the
      Indenture pursuant to which such Equipment Note is issued, not in its
      individual capacity but solely as trustee; and Owner Trustees means all of
      the Owner Trustees party to any of the Indentures.

            Participation Agreement: Means each Participation Agreement to be
      entered into by the Trustee pursuant to the Note Purchase Agreement, as
      the same may be amended, supplemented or otherwise modified in accordance
      with its terms.

            Paying Agent:  Means the paying agent maintained and appointed
      for the Certificates pursuant to Section 7.12.

            Permitted Investments: Means obligations of the United States of
      America or agencies or instrumentalities thereof for the payment of which
      the full faith and credit of the United States of America is pledged,
      maturing in not more than 60 days after the date of acquisition thereof or
      such lesser time as is required for the distribution of any Special
      Payments on a Special Distribution Date.

            Person: Means any person, including any individual, corporation,
      limited liability company, partnership, joint venture, association,
      joint-stock company, trust, trustee, unincorporated organization, or
      government or any agency or political subdivision thereof.
<PAGE>   15
                                      -10-


            Pool Balance: Means, as of any date, (i) the original aggregate face
      amount of the Certificates less (ii) the aggregate amount of all payments
      made in respect of such Certificates other than payments made in respect
      of interest or premium thereon or reimbursement of any costs or expenses
      incurred in connection therewith less (iii) the aggregate amount of unused
      Deposits distributed as a Final Withdrawal other than payments in respect
      of interest or premium thereon. The Pool Balance as of any Distribution
      Date shall be computed after giving effect to the payment of principal, if
      any, on the Equipment Notes or other Trust Property held in such Trust and
      the distribution thereof to be made on such Distribution Date and the
      distribution of the Final Withdrawal to be made on such Distribution Date.

            Pool Factor: Means, as of any date, the quotient (rounded to the
      seventh decimal place) computed by dividing (i) the Pool Balance as at
      such date by (ii) the original aggregate face amount of the Certificates.
      The Pool Factor as of any Distribution Date shall be computed after giving
      effect to the payment of principal, if any, on the Equipment Notes or
      other Trust Property and the distribution thereof to be made on such
      Distribution Date and the distribution of the Final Withdrawal to be made
      on such Distribution Date.

            PTC Event of Default: Means any failure to pay within 10 Business
      Days of the due date thereof: (i) the outstanding Pool Balance on the
      Final Legal Distribution Date or (ii) interest due on the Certificates on
      any Distribution Date (unless the Subordination Agent shall have made an
      Interest Drawing or Drawings (as defined in the Intercreditor Agreement),
      or a withdrawal or withdrawals pursuant to Section 3.6(f) of the
      Intercreditor Agreement, with respect thereto in an aggregate amount
      sufficient to pay such interest and shall have distributed such amount to
      the Trustee).

            QIB:   Means a qualified institutional buyer as defined in Rule
      144A.

            Record Date: Means (i) for Scheduled Payments to be distributed on
      any Regular Distribution Date, other than the final distribution, the 15th
      day (whether or not a Business Day) preceding such Regular Distribution
      Date, and (ii) for Special Payments to be distributed on any Special
      Distribution Date, other than the final distribution, the 15th day
      (whether or not a Business Day) preceding such Special Distribution Date.

            Register and Registrar:  Mean the register maintained and the
      registrar appointed pursuant to Sections 3.04 and 7.12.

            Registration Event:  Means the declaration of the effectiveness
      by the SEC of the Exchange Offer Registration Statement or the Shelf
      Registration Statement.

            Registration Rights Agreement: Means the Exchange and Registration
      Rights Agreement dated as of October 6, 1998, among the Initial
      Purchasers, the Trustee, the Other Trustees and the Company, as amended,
      supplemented or otherwise modified from time to time in accordance with
      its terms.

            Regular Distribution Date: With respect to distributions of
      Scheduled Payments in respect of the Certificates, means each date
      designated as a Regular Distribution Date
<PAGE>   16
                                      -11-


      in the Certificates issued pursuant to this Agreement, until payment of
      all the Scheduled Payments to be made under the Equipment Notes held in
      the Trust have been made; provided, however, that, if any such day shall
      not be a Business Day, the related distribution shall be made on the next
      succeeding Business Day without additional interest.

            Regulation S: Means Regulation S under the Securities Act or any
      successor regulation thereto.

            Regulation S Definitive Certificates:  Has the meaning specified
      in Section 3.01(e).

            Regulation S Global Certificates:  Has the meaning specified in
      Section 3.01(d).

            Related Pass Through Trust Agreement: Means the Pass Through Trust
      Agreement relating to America West Airlines Pass Through Trust, Series
      1998-1C-S, dated the date hereof, between the Company and the institution
      acting as trustee thereunder, which agreement becomes effective upon the
      execution and delivery of the Assignment and Assumption Agreement pursuant
      to Section 11.01.

            Related Trust:  Means the America West Pass Through Trust, Series
      1998-1C-S, formed under the Related Pass Through Trust Agreement.

            Related Trustee: Means the trustee under the Related Pass Through
      Trust Agreement.

            Responsible Officer: With respect to the Trustee, any Loan Trustee
      and any Owner Trustee, means any officer in the Corporate Trust Office of
      the Trustee, Loan Trustee or Owner Trustee or any other officer
      customarily performing functions similar to those performed by the persons
      who at the time shall be such officers, respectively, or to whom any
      corporate trust matter is referred because of his knowledge of and
      familiarity with a particular subject.

            Restricted Definitive Certificates:  Has the meaning specified in
      Section 3.01(e).

            Restricted Global Certificate: Has the meaning specified in Section
      3.01(c).

            Restricted Legend:  Has the meaning specified in Section 3.02.

            Restricted Period:  Has the meaning specified in Section 3.01(d).

            Rule 144A: Means Rule 144A under the Securities Act and any
      successor rule thereto.

            Scheduled Payment: With respect to any Equipment Note, means (i) any
      payment of principal or interest on such Equipment Note (other than any
      such payment which is not in fact received by the Subordination Agent
      within five days of the date on which such payment is scheduled to be
      made) due from the obligor thereon or (ii) any payment
<PAGE>   17
                                      -12-


      of interest on the Certificates with funds drawn under any Liquidity
      Facility, which payment represents the installment of principal at the
      stated maturity of such installment of principal on such Equipment Note,
      the payment of regularly scheduled interest accrued on the unpaid
      principal amount of such Equipment Note, or both; provided that any
      payment of principal, premium, if any, or interest resulting from the
      redemption or purchase of any Equipment Note shall not constitute a
      Scheduled Payment.

            SEC: Means the Securities and Exchange Commission, as from time to
      time constituted or created under the United States Securities Exchange
      Act of 1934, as amended, or, if at any time after the execution of this
      instrument such Commission is not existing and performing the duties now
      assigned to it under the Trust Indenture Act, then the body performing
      such duties on such date.

            Securities Act:  Means the United States Securities Act of 1933,
      as amended from time to time, or any successor thereto.

            Shelf Registration Statement: Means the shelf registration statement
      which may be required to be filed by the Company with the SEC pursuant to
      any Registration Rights Agreement, other than an Exchange Offer
      Registration Statement.

            Special Distribution Date: Means each date on which a Special
      Payment is to be distributed as specified in this Agreement; provided,
      however, that, if any such day shall not be a Business Day, the related
      distribution shall be made on the next succeeding Business Day without
      additional interest.

            Special Redemption Premium:  Means the premium payable by the
      Company in respect of the Final Withdrawal pursuant to the Note
      Purchase Agreement.

            Special Payment: Means any payment (other than a Scheduled Payment)
      in respect of, or any proceeds of, any Equipment Note or Trust Indenture
      Estate (as defined in each Indenture) or Special Redemption Premium.

            Special Payments Account:  Means the account or accounts created
      and maintained pursuant to Section 4.01(b).

            Subordination Agent:  Has the meaning specified in the
      Intercreditor Agreement.

            Substitute Aircraft:  Has the meaning specified in the Note
      Purchase Agreement.

            Tax: Means all license, recording, documentary, registration and
      other similar fees and all taxes, levies, imposts, duties, charges,
      assessments or withholdings of any nature whatsoever imposed by any Taxing
      Authority, together with any penalties, additions to tax, fines or
      interest thereon or additions thereto.

            Taxing Authority: Means any federal, state or local government or
      other taxing authority in the United States, any foreign government or any
      political subdivision or taxing authority thereof, any international
      taxing authority or any territory or possession of the United States or
      any taxing authority thereof.
<PAGE>   18
                                      -13-


            TIN:  Has the meaning specified in Section 7.16.

            Transfer Date:  Has the meaning specified in Section 11.01.

            Triggering Event:  Has the meaning assigned to such term in the
      Intercreditor Agreement.

            Trust:  Means the trust created by this Agreement, the estate of
      which consists of the Trust Property.

            Trust Indenture Act:  Means the United States Trust Indenture Act
      of 1939, as amended from time to time, or any successor thereto.

            Trust Property: Means (i) the Equipment Notes held as the property
      of the Trust and, subject to the Intercreditor Agreement, all monies at
      any time paid thereon and all monies due and to become due thereunder,
      (ii) funds from time to time deposited in the Certificate Account and the
      Special Payments Account and, subject to the Intercreditor Agreement, any
      proceeds from the sale by the Trustee pursuant to Article VI hereof of any
      Equipment Note and (iii) all rights of the Trust and the Trustee, on
      behalf of the Trust, under the Intercreditor Agreement, the Escrow
      Agreement, the Note Purchase Agreement and the Liquidity Facilities,
      including, without limitation, all rights to receive certain payments
      thereunder, and all monies paid to the Trustee on behalf of the Trust
      pursuant to the Intercreditor Agreement or the Liquidity Facilities,
      provided, that rights with respect to the Deposits or under the Escrow
      Agreement, except for the right to direct withdrawals for the purchase of
      Equipment Notes to be held herein, will not constitute Trust Property.

            Trustee: Means Wilmington Trust Company, or its successor in
      interest, and any successor or other trustee appointed as provided herein.

            Trustee's Lien:  Has the meaning specified in Section 7.17.

            Unindemnified Tax: Means (i) any Tax imposed on the net income, net
      worth or capital, or any franchise Tax or similar doing business Tax, of
      the Pass Through Trustee (other than any such Tax imposed as a result of
      the Company's assumption of the Equipment Notes pursuant to the purchase
      of an aircraft on an EBO Date or a Material Adverse Tax Event), (ii) any
      withholding Tax imposed by the United States (including, without
      limitation, any withholding Tax imposed by the United States which is
      imposed or increased as a result of the Pass Through Trustee failing to
      deliver to the Company any certificate or document necessary to establish
      that payments under this Agreement are exempt from withholding Tax), and
      (iii) any Avoidable Tax.

            Section 1.02. Compliance Certificates and Opinions. Upon any
application or request (except with respect to matters set forth in Article II)
by the Company, any Owner Trustee or any Loan Trustee to the Trustee to take any
action under any provision of this Agreement, the Company, such Owner Trustee or
such Loan Trustee, as the case may be, shall furnish to the Trustee (i) an
Officer's Certificate stating that, in the opinion of the signers, all
conditions precedent, if any, provided for in this Agreement relating to the
proposed action have
<PAGE>   19
                                      -14-


been complied with and (ii) an Opinion of Counsel stating that in the opinion of
such counsel all such conditions precedent, if any, have been complied with,
except that in the case of any such application or request as to which the
furnishing of such documents is specifically required by any provision of this
Agreement relating to such particular application or request, no additional
certificate or opinion need be furnished.

            Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Agreement (other than a certificate
provided pursuant to Section 8.04(e)) shall include:

            (1) a statement that each individual signing such certificate or
      opinion has read such covenant or condition and the definitions in this
      Agreement relating thereto;

            (2) a brief statement as to the nature and scope of the examination
      or investigation upon which the statements or opinions contained in such
      certificate or opinion are based;

            (3) a statement that, in the opinion of each such individual, he has
      made such examination or investigation as is necessary to enable him to
      express an informed opinion as to whether or not such covenant or
      condition has been complied with; and

            (4) a statement as to whether, in the opinion of each such
      individual, such condition or covenant has been complied with.

            Section 1.03. Form of Documents Delivered to Trustee. In any case
where several matters are required to be certified by, or covered by an opinion
of, any specified Person, it is not necessary that all such matters be certified
by, or covered by the opinion of, only one such Person, or that they be so
certified or covered by only one document, but one such Person may certify or
give an opinion with respect to some matters and one or more other such Persons
as to other matters and any such Person may certify or give an opinion as to
such matters in one or several documents.

            Where any Person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Agreement or, in respect of the Certificates, this
Agreement, they may, but need not, be consolidated and form one instrument.

            Section 1.04. Directions of Certificateholders. (a) Any direction,
consent, request, demand, authorization, notice, waiver or other action provided
by this Agreement to be given or taken by Certificateholders (a "Direction") may
be embodied in and evidenced by one or more instruments of substantially similar
tenor signed by such Certificateholders in person or by an agent or proxy duly
appointed in writing; and, except as herein otherwise expressly provided, such
action shall become effective when such instrument or instruments are delivered
to the Trustee and, where it is hereby expressly required pursuant to this
Agreement, to the Company or any Loan Trustee. Proof of execution of any such
instrument or of a writing appointing any such agent or proxy shall be
sufficient for any purpose of this Agreement and conclusive in favor of the
Trustee, the Company and any Loan Trustee, if made in the manner provided in
this Section.
<PAGE>   20
                                      -15-


            (b) The fact and date of the execution by any Person of any such
instrument or writing may be proved by the certificate of any notary public or
other officer of any jurisdiction authorized to take acknowledgments of deeds or
administer oaths that the Person executing such instrument acknowledged to him
the execution thereof, or by an affidavit of a witness to such execution sworn
to before any such notary or such other officer and where such execution is by
an officer of a corporation or association or a member of a partnership, on
behalf of such corporation, association or partnership, such certificate or
affidavit shall also constitute sufficient proof of his authority. The fact and
date of the execution of any such instrument or writing, or the authority of the
Person executing the same, may also be proved in any other reasonable manner
which the Trustee deems sufficient.

            (c) In determining whether the Certificateholders of the requisite
Fractional Undivided Interests of Certificates Outstanding have given any
Direction under this Agreement, Certificates owned by the Company or any
Affiliate thereof shall be disregarded and deemed not to be Outstanding for
purposes of any such determination. In determining whether the Trustee shall be
protected in relying upon any such Direction, only Certificates which the
Trustee knows to be so owned shall be so disregarded. Notwithstanding the
foregoing, (i) if any such Person owns 100% of the Certificates Outstanding,
such Certificates shall not be so disregarded, and (ii) if any amount of
Certificates so owned by any such Person have been pledged in good faith, such
Certificates shall not be disregarded if the pledgee establishes to the
satisfaction of the Trustee the pledgee's right so to act with respect to such
Certificates and that the pledgee is not the Company or any Affiliate thereof.

            (d) For all purposes of this Agreement, all Initial Certificates and
all Exchange Certificates shall vote and take all other actions of
Certificateholders together as one series of Certificates.

            (e) The Company may at its option, by delivery of an Officer's
Certificate to the Trustee, set a record date to determine the
Certificateholders entitled to give any Direction. Notwithstanding Section
316(c) of the Trust Indenture Act, such record date shall be the record date
specified in such Officer's Certificate, which shall be a date not more than 30
days prior to the first solicitation of Certificateholders in connection
therewith. If such a record date is fixed, such Direction may be given before or
after such record date, but only the Certificateholders of record at the close
of business on such record date shall be deemed to be Certificateholders for the
purposes of determining whether Certificateholders of the requisite proportion
of Outstanding Certificates have authorized or agreed or consented to such
Direction, and for that purpose the Outstanding Certificates shall be computed
as of such record date; provided that no such Direction by the
Certificateholders on such record date shall be deemed effective unless it shall
become effective pursuant to the provisions of this Agreement not later than one
year after such record date.

            (f) Any Direction by the Holder of any Certificate shall bind the
Holder of every Certificate issued upon the transfer thereof or in exchange
therefor or in lieu thereof, whether or not notation of such Direction is made
upon such Certificate.
<PAGE>   21
                                      -16-


            (g) Except as otherwise provided in Section 1.04(c), Certificates
owned by or pledged to any Person shall have an equal and proportionate benefit
under the provisions of this Agreement, without preference, priority, or
distinction as among all of the Certificates.


                                   ARTICLE II

                       ORIGINAL ISSUANCE OF CERTIFICATES;
                         ACQUISITION OF EQUIPMENT NOTES

            Section 2.01. Issuance of Certificates; Acquisition of Equipment
Notes. (a) The Trustee is hereby directed (i) to execute and deliver the
Intercreditor Agreement, the Registration Rights Agreement, the Escrow Agreement
and the Note Purchase Agreement on or prior to the Issuance Date, each in the
form delivered to the Trustee by the Company and (ii) subject to the respective
terms thereof, to perform its obligations thereunder. Upon request of the
Company and the satisfaction or waiver of the closing conditions specified in
the Certificate Purchase Agreement, the Trustee shall execute, deliver,
authenticate, issue and sell Certificates in authorized denominations equaling
in the aggregate the amount set forth, with respect to the Trust, in Schedule II
to the Certificate Purchase Agreement evidencing the entire ownership interest
in the Trust, which amount equals the maximum aggregate principal amount of
Equipment Notes which may be purchased by the Trustee pursuant to the Note
Purchase Agreement. Except as provided in Sections 3.04, 3.05, 3.06, 3.07 and
3.10 hereof, the Trustee shall not execute, authenticate or deliver Certificates
in excess of the aggregate amount specified in this paragraph.

            (b) On or after the Issuance Date, the Company may deliver from time
to time to the Trustee a Delivery Notice relating to one or more Equipment
Notes. After receipt of a Delivery Notice and in any case no later than one
Business Day prior to a Delivery Date as to which such Delivery Notice relates
(the "Applicable Delivery Date") (or, if the Issuance Date is an Applicable
Delivery Date, on the Issuance Date), the Trustee shall (as and when specified
in the Delivery Notice) instruct the Escrow Agent to provide a Notice of
Purchase Withdrawal to the Depositary requesting (A) the withdrawal of one or
more Deposits on the Applicable Delivery Date in accordance with and to the
extent permitted by the terms of the Escrow Agreement and the Deposit Agreement
and (B) the payment of all, or a portion, of such Deposit or Deposits in an
amount equal in the aggregate to the purchase price of such Equipment Notes to
or on behalf of the Owner Trustee or the Company, as the case may be, issuing
such Equipment Notes, all as shall be described in the Delivery Notice; provided
that, if the Issuance Date is an Applicable Delivery Date, such purchase price
shall be paid from a portion of the proceeds of the sale of the Certificates.
The Trustee shall (as and when specified in such Delivery Notice), subject to
the conditions set forth in Section 2 of the Note Purchase Agreement, enter into
and perform its obligations under the Participation Agreement specified in such
Delivery Notice (the "Applicable Participation Agreement") and cause such
certificates, documents and legal opinions relating to the Trustee to be duly
delivered as required by the Applicable Participation Agreement. If at any time
prior to the Applicable Delivery Date, the Trustee receives a notice of
postponement pursuant to Section 2(e) or 2(f) of the Note Purchase Agreement,
then the Trustee shall give the Depositary (with a copy to the Escrow Agent) a
notice of cancellation of such Notice of Purchase Withdrawal relating to such
Deposit or
<PAGE>   22
                                      -17-


Deposits on such Applicable Delivery Date. Upon satisfaction of the conditions
specified in the Note Purchase Agreement and the Applicable Participation
Agreement, the Trustee shall purchase the applicable Equipment Notes with the
proceeds of the withdrawals of one or more Deposits made on the Applicable
Delivery Date in accordance with the terms of the Deposit Agreement and the
Escrow Agreement (or, if the Issuance Date is the Applicable Delivery Date with
respect to such Applicable Participation Agreement, from a portion of the
proceeds of the sale of the Certificates). The purchase price of such Equipment
Notes shall equal the principal amount of such Equipment Notes. Amounts
withdrawn from such Deposit or Deposits in excess of the purchase price of the
Equipment Notes or to the extent not applied on the Applicable Delivery Date to
the purchase price of the Equipment Notes, shall be re-deposited by the Trustee
with the Depositary on the Applicable Delivery Date in accordance with the terms
of the Deposit Agreement.

            Section 2.02. Withdrawal of Deposits. If any Deposits remain
outstanding on the Business Day next succeeding the Cut-Off Date, (i) (A) the
Trustee shall give the Escrow Agent notice that the Trustee's obligation to
purchase Equipment Notes under the Note Purchase Agreement has terminated and
instruct the Escrow Agent to provide a notice of Final Withdrawal to the
Depositary substantially in the form of Exhibit B to the Deposit Agreement (the
"Final Withdrawal Notice") and (B) the Trustee will make a demand upon the
Company under the Note Purchase Agreement for an amount equal to the Special
Redemption Premium, if applicable, such payment to be made on the Final
Withdrawal Date.

            Section 2.03. Acceptance by Trustee. The Trustee, upon the execution
and delivery of this Agreement, acknowledges its acceptance of all right, title
and interest in and to the Trust Property and declares that the Trustee holds
and will hold such right, title and interest for the benefit of all then present
and future Certificateholders, upon the trusts herein set forth. Subject to
Section 7.14, the Trustee shall take all actions reasonably necessary to effect
the registration of all such Equipment Notes in the name of the Subordination
Agent. By its payment for and acceptance of each Certificate issued to it under
this Agreement, each initial Certificateholder as grantor of the Trust thereby
joins in the creation and declaration of the Trust.

            Section 2.04. Limitation of Powers. The Trust is constituted solely
for the purpose of making the investment in the Equipment Notes, and, except as
set forth herein, the Trustee shall not be authorized or empowered to acquire
any other investments or engage in any other activities and, in particular, the
Trustee shall not be authorized or empowered to do anything that would cause
such Trust to fail to qualify as a "grantor trust" for federal income tax
purposes (including as subject to this restriction, acquiring any Aircraft (as
defined in the respective Indentures) by bidding such Equipment Notes or
otherwise, or taking any action with respect to any such Aircraft once
acquired).


                                   ARTICLE III

                                THE CERTIFICATES

            Section 3.01. Title, Form, Denomination and Execution of
Certificates. (a) The Initial Certificates shall be known as the "7.84% Initial
Pass Through Certificates, Series 1998-1C-O" and the Exchange Certificates shall
be known as the "7.84% Exchange Pass Through
<PAGE>   23
                                      -18-


Certificates, Series 1998-1C-O", in each case, of the Trust. Each Certificate
will represent a fractional undivided interest in the Trust and shall be
substantially in the form set forth as Exhibit A hereto, with such appropriate
insertions, omissions, substitutions and other variations as are required or
permitted by this Agreement and may have such letters, numbers or other marks of
identification and such legends or endorsements placed thereon as may be
required to comply with the rules of any securities exchange or as may,
consistently herewith, be determined by the Trustee or the officers executing
such Certificates, as evidenced by the Trustee's or officer's execution of the
Certificates (provided that such letters, numbers or other marks of
identification and such legends or endorsements are in a form acceptable to the
Company). At the Escrow Agent's request under the Escrow Agreement, the Trustee
shall affix the corresponding Escrow Receipt to each Certificate. In any event,
any transfer or exchange of any Certificate shall also effect a transfer or
exchange of the related Escrow Receipt. Prior to the Final Withdrawal Date, no
transfer or exchange of any Certificate shall be permitted unless the
Corresponding Escrow Receipt is attached thereto and also is so transferred or
exchanged. By acceptance of any Certificate to which an Escrow Receipt is
attached, each Holder of such a Certificate acknowledges and accepts the
restrictions on transfer of the Escrow Receipt set forth herein and in the
Escrow Agreement.

            (b) The Initial Certificates shall be issued only in fully
registered form without coupons and only in denominations of $100,000 or
integral multiples of $1,000 in excess thereof, except that one Certificate may
be issued in a different denomination. The Exchange Certificates will be issued
in denominations of $1,000 or integral multiples thereof, except that one
Certificate may be issued in a different denomination. Each Certificate shall be
dated the date of its authentication. The aggregate Fractional Undivided
Interest of Certificates shall not at any time exceed $17,705,000.

            (c) The Initial Certificates offered and sold in reliance on Rule
144A shall be issued in the form of one or more Global Certificates
substantially in the form of Exhibit A hereto with such applicable legends as
are provided for in Section 3.02 (each a "Restricted Global Certificate") duly
executed and authenticated by the Trustee as hereinafter provided. Such
Restricted Global Certificates shall be in registered form and be registered in
the name of DTC and deposited with the Trustee, at its Corporate Trust Office,
as custodian for DTC. The aggregate principal amount of any Restricted Global
Certificate may from time to time be increased or decreased by adjustments made
on the records of the Trustee, as custodian for DTC for such Restricted Global
Certificate, as provided in Section 3.06 hereof, which adjustments shall be
conclusive as to the aggregate principal amount of any such Global Certificate.

            (d) The Initial Certificates offered and sold outside the United
States in reliance on Regulation S shall be issued in the form of one or more
global Certificates substantially in the form of Exhibit A hereto (each a
"Regulation S Global Certificate") duly executed and authenticated by the
Trustee as hereinafter provided. Such Regulation S Global Certificates shall be
in registered form and be registered in the name of DTC and deposited with the
Trustee, at its Corporate Trust Office, as custodian for DTC, for credit
initially and during the Restricted Period (hereinafter defined) to the
respective accounts of beneficial owners of such Certificates (or to such other
accounts as they may direct) at Morgan Guaranty Trust Company of New York,
Brussels office, as operator of Euroclear or Cedel. As used herein, the term
"Restricted Period", with respect to the Regulation S Global Certificates
offered and sold in
<PAGE>   24
                                      -19-


reliance on Regulation S, means the period of 40 consecutive days beginning on
and including the later of (i) the day on which the Certificates are first
offered to persons other than distributors (as defined in Regulation S) in
reliance on Regulation S and (ii) the date of the closing of the offering under
the Certificate Purchase Agreement. The aggregate principal amount of any
Regulation S Global Certificate may from time to time be increased or decreased
by adjustments made on the records of the Trustee, as custodian for DTC for such
Global Certificate, as provided in Section 3.06 hereof, which adjustments shall
be conclusive as to the aggregate principal amount of any such Global
Certificate. The Restricted Global Certificate and Regulation S Global
Certificate are sometimes collectively referred to herein as the "Global
Certificates".

            (e) Initial Certificates offered and sold to any Institutional
Accredited Investor which is not a QIB in a transaction exempt from registration
under the Securities Act (and other than as described in Section 3.01(d)) shall
be issued substantially in the form of Exhibit A hereto in definitive, fully
registered form without interest coupons with such applicable legends as are
provided for in Section 3.02 (the "Restricted Definitive Certificates") duly
executed and authenticated by the Trustee as hereinafter provided. Certificates
issued pursuant to Section 3.05(b) in exchange for interests in a Regulation S
Global Certificate shall be issued in definitive, fully registered form without
interest coupons (the "Regulation S Definitive Certificates"). The Restricted
Definitive Certificates and the Regulation S Definitive Certificates are
sometimes collectively referred to herein as the "Definitive Certificates".

            (f) The Exchange Certificates shall be issued in the form of one or
more global Certificates substantially in the form of Exhibit A hereto (each, a
"Global Exchange Certificate"), except that (i) the Restricted Legend
(hereinafter defined) shall be omitted and (ii) such Exchange Certificates shall
contain such appropriate insertions, omissions, substitutions and other
variations from the form set forth in Exhibit A hereto relating to the nature of
the Exchange Certificates as the Responsible Officer of the Trustee executing
such Exchange Certificates on behalf of the Trust may determine, as evidenced by
such officer's execution on behalf of the Trust of such Exchange Certificates.
Such Global Exchange Certificates shall be in registered form and be registered
in the name of DTC and deposited with the Trustee, at its Corporate Trust
Office, as custodian for DTC. The aggregate principal amount of any Global
Exchange Certificate may from time to time be increased or decreased by
adjustments made on the records of the Trustee, as custodian for DTC for such
Global Exchange Certificate, which adjustments shall be conclusive as to the
aggregate principal amount of any such Global Exchange Certificate. Subject to
clause (i) and (ii) of the first sentence of this Section 3.01(f), the terms
hereof applicable to Restricted Global Certificates and/or Global Certificates
shall apply to the Global Exchange Certificates, mutatis mutandis.

            (g) The Definitive Certificates shall be in registered form and
shall be typed, printed, lithographed or engraved or produced by any combination
of these methods or may be produced in any other manner, all as determined by
the officers executing such Certificates, as evidenced by their execution of
such Certificates.

            Section 3.02. Restrictive Legends. All Initial Certificates issued
pursuant to this Agreement for resale pursuant to Rule 144A or offered and sold
to any Institutional Accredited Investor which is not a QIB (including any
Global Certificate issued upon registration of
<PAGE>   25
                                      -20-


transfer, in exchange for or in lieu of such Certificates) shall be "Restricted
Certificates" and shall bear a legend to the following effect (the "Restricted
Legend") unless the Company and the Trustee determine otherwise consistent with
applicable law:

            THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE U.S. SECURITIES
      ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND ACCORDINGLY, MAY NOT
      BE OFFERED OR SOLD WITHIN THE UNITED STATES OR TO, OR FOR THE ACCOUNT OR
      BENEFIT OF, ANY PERSONS EXCEPT AS SET FORTH IN THE FOLLOWING SENTENCE. BY
      ITS ACQUISITION HEREOF, THE HOLDER (1) REPRESENTS THAT (A) IT IS A
      "QUALIFIED INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A UNDER THE
      SECURITIES ACT), (B) IT IS AN INSTITUTIONAL "ACCREDITED INVESTOR" (AS
      DEFINED IN RULE 501(a)(1), (2), (3) OR (7) OF REGULATION D UNDER THE
      SECURITIES ACT) (AN "INSTITUTIONAL ACCREDITED INVESTOR") OR (C) IT IS NOT
      A U.S. PERSON AND IS ACQUIRING THIS CERTIFICATE IN AN OFFSHORE TRANSACTION
      IN COMPLIANCE WITH REGULATION S UNDER THE SECURITIES ACT; (2) AGREES THAT
      IT WILL NOT WITHIN TWO YEARS AFTER THE LATER OF THE ORIGINAL ISSUANCE OF
      THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS CERTIFICATE WAS HELD BY
      AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY AFFILIATE OF ANY OF SUCH
      PERSONS RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE EXCEPT (A) TO
      AMERICA WEST AIRLINES, INC., (B) TO A QUALIFIED INSTITUTIONAL BUYER IN
      COMPLIANCE WITH RULE 144A UNDER THE SECURITIES ACT, (C) OUTSIDE THE UNITED
      STATES IN AN OFFSHORE TRANSACTION IN COMPLIANCE WITH RULE 904 UNDER THE
      SECURITIES ACT, (D) PURSUANT TO THE EXEMPTION FROM REGISTRATION PROVIDED
      BY RULE 144 UNDER THE SECURITIES ACT (IF AVAILABLE) OR (E) PURSUANT TO AN
      EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT; AND (3) AGREES
      THAT IF IT SHOULD RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE IT WILL
      DELIVER TO EACH PERSON TO WHOM THIS CERTIFICATE IS TRANSFERRED A NOTICE
      SUBSTANTIALLY TO THE EFFECT OF THIS LEGEND. IN CONNECTION WITH ANY
      TRANSFER OF THIS CERTIFICATE WITHIN TWO YEARS AFTER THE LATER OF THE
      ORIGINAL ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS
      CERTIFICATE WAS HELD BY AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY
      AFFILIATE OF ANY OF SUCH PERSONS, THE HOLDER MUST CHECK THE APPROPRIATE
      BOX SET FORTH ON THE REVERSE HEREOF RELATING TO THE MANNER OF SUCH
      TRANSFER AND SUBMIT THIS CERTIFICATE TO THE TRUSTEE. AS USED HEREIN, THE
      TERMS "OFFSHORE TRANSACTION", "UNITED STATES" AND "U.S. PERSON" HAVE THE
      MEANINGS GIVEN TO THEM BY REGULATION S UNDER THE SECURITIES ACT. THE PASS
      THROUGH TRUST AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO
      REFUSE TO REGISTER ANY TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE
      FOREGOING RESTRICTIONS.

            Each Global Certificate shall bear the following legend on the face
thereof:
<PAGE>   26
                                      -21-


            UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE
      OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE
      TRUSTEE OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT,
      AND ANY CERTIFICATE ISSUED IN EXCHANGE FOR THIS CERTIFICATE IS REGISTERED
      IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN
      AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT HEREON IS MADE TO CEDE &
      CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED
      REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE
      OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED
      OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

            TRANSFERS OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO TRANSFERS
      IN WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A SUCCESSOR THEREOF OR
      SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL
      CERTIFICATE SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE
      RESTRICTIONS SET FORTH IN SECTIONS 3.05 AND 3.06 OF THE PASS THROUGH TRUST
      AGREEMENT REFERRED TO HEREIN.

            Section 3.03. Authentication of Certificates. (a) On the Issuance
Date, the Trustee shall duly execute, authenticate and deliver Certificates in
authorized denominations equaling in the aggregate the amount set forth, with
respect to the Trust, in Schedule II to the Certificate Purchase Agreement,
evidencing the entire ownership of the Trust, which amount equals the maximum
aggregate principal amount of Equipment Notes which may be purchased by the
Trustee pursuant to the Note Purchase Agreement.

            (b) No Certificate shall be entitled to any benefit under this
Agreement or be valid or obligatory for any purpose, unless there appears on
such Certificate a certificate of authentication substantially in the form
provided for herein executed by the Trustee by the manual signature of one of
its authorized signatories, and such certificate upon any Certificate shall be
conclusive evidence, and the only evidence, that such Certificate has been duly
authenticated and delivered hereunder.

            (c) Certificates bearing the manual or facsimile signature of an
individual who was, at the time when such signature was affixed, authorized to
sign on behalf of the Trustee shall be valid and binding obligations of the
Trust notwithstanding that such individual has ceased to be so authorized prior
to the authentication and delivery of such Certificates or did not hold such
office on the date of such Certificates.

            Section 3.04. Transfer and Exchange. The Trustee shall cause to be
kept at the office or agency to be maintained by it in accordance with the
provisions of Section 7.12 a register (the "Register") of the Certificates in
which, subject to such reasonable regulations as it may prescribe, the Trustee
shall provide for the registration of such Certificates and of transfers and
exchanges of such Certificates as herein provided. The Trustee shall initially
be the registrar (the "Registrar") for the purpose of registering such
Certificates and transfers and exchanges of
<PAGE>   27
                                      -22-


such Certificates as herein provided. The Company, upon notice to the Trustee,
may change the Registrar at any time.

            All Certificates issued upon any registration of transfer or
exchange of Certificates shall be valid obligations of the Trust, evidencing the
same interest therein, and entitled to the same benefits under this Trust
Agreement, as the Certificates surrendered upon such registration of transfer or
exchange.

            A Certificateholder may transfer a Certificate, or request that a
Certificate be exchanged for Certificates in an aggregate Fractional Undivided
Interest equal to the Fractional Undivided Interest of such Certificate
surrendered for exchange of other authorized denominations, by surrender of such
Certificate to the Trustee with the form of transfer notice thereon duly
completed and executed, and otherwise complying with the terms of this
Agreement, including providing evidence of compliance with any restrictions on
transfer, in form satisfactory to the Trustee and the Registrar; provided that
no exchanges of Initial Certificates for Exchange Certificates shall occur until
an Exchange Offer Registration Statement shall have been declared effective by
the SEC (notice of which shall be provided to the Trustee by the Company). No
such transfer shall be effected until, and such transferee shall succeed to the
rights of a Certificateholder only upon, final acceptance and registration of
the transfer by the Registrar in the Register. Prior to the registration of any
transfer by a Certificateholder as provided herein, the Trustee shall treat the
person in whose name the Certificate is registered as the owner thereof for all
purposes, and the Trustee shall not be affected by notice to the contrary.
Furthermore, DTC shall, by acceptance of a Global Certificate, agree that
transfers of beneficial interests in such Global Certificate may be effected
only through a book-entry system maintained by DTC (or its agent) and that
ownership of a beneficial interest in the Certificate shall be required to be
reflected in a book-entry. When Certificates are presented to the Registrar with
a request to register the transfer thereof or to exchange them for other
authorized denominations of a Certificate in a Fractional Undivided Interest
equal to the aggregate Fractional Undivided Interest of Certificates surrendered
for exchange, the Registrar shall register the transfer or make the exchange as
requested if its requirements for such transactions are met.

            To permit registrations of transfers and exchanges in accordance
with the terms, conditions and restrictions hereof, the Trustee shall execute
and authenticate Certificates at the Registrar's request. No service charge
shall be made to a Certificateholder for any registration of transfer or
exchange of Certificates, but the Trustee shall require payment of a sum
sufficient to cover any tax or governmental charge that may be imposed in
connection with any transfer or exchange of Certificates. All Certificates
surrendered for registration of transfer or exchange shall be canceled and
subsequently destroyed by the Trustee.

            Section 3.05. Book-Entry Provisions for Restricted Global
Certificates and Regulation S Global Certificates. (a) Members of, or
participants in, DTC ("Agent Members") shall have no rights under this Agreement
with respect to any Global Certificate held on their behalf by DTC, or the
Trustee as its custodian, and DTC may be treated by the Trustee and any agent of
the Trustee as the absolute owner of such Global Certificate for all purposes
whatsoever. Notwithstanding the foregoing, nothing herein shall prevent the
Trustee or any agent of the Trustee from giving effect to any written
certification, proxy or other authorization furnished by DTC or shall impair, as
between DTC and its Agent Members, the operation of customary
<PAGE>   28
                                      -23-


practices governing the exercise of the rights of a holder of any Certificate.
Upon the issuance of any Global Certificate, the Registrar or its duly appointed
agent shall record DTC as the registered holder of such Global Certificate.

            (b) Transfers of any Global Certificate shall be limited to
transfers of such Restricted Global Certificate or Regulation S Global
Certificate in whole, but not in part, to DTC. Beneficial interests in the
Restricted Global Certificate and any Regulation S Global Certificate may be
transferred in accordance with the rules and procedures of DTC and the
provisions of Section 3.06. Beneficial interests in a Restricted Global
Certificate or a Regulation S Global Certificate shall be delivered to all
beneficial owners thereof in the form of Restricted Definitive Certificates or
Regulation S Definitive Certificates, as the case may be, if (i) DTC notifies
the Trustee that it is unwilling or unable to continue as depositary for such
Restricted Global Certificate or Regulation S Global Certificate, as the case
may be, and a successor depositary is not appointed by the Trustee within 90
days of such notice, and (ii) after the occurrence and during the continuance of
an Event of Default, owners of beneficial interests in a Global Certificate with
Fractional Undivided Interests aggregating not less than a majority in interest
in the Trust advise the Trustee, the Company and DTC through Agent Members in
writing that the continuation of a book-entry system through DTC or its
successor is no longer in their best interests.

            (c) Any beneficial interest in one of the Global Certificates that
is transferred to a Person who takes delivery in the form of an interest in
another Global Certificate will, upon such transfer, cease to be an interest in
such Global Certificate and become an interest in the other Global Certificate
and, accordingly, will thereafter be subject to all transfer restrictions, if
any, and other procedures applicable to beneficial interests in such other
Global Certificate for as long as it remains such an interest.

            (d) In connection with the transfer of an entire Restricted Global
Certificate or an entire Regulation S Global Certificate to the beneficial
owners thereof pursuant to paragraph (b) of this Section 3.05, such Restricted
Global Certificate or Regulation S Global Certificate, as the case may be, shall
be deemed to be surrendered to the Trustee for cancellation, and the Trustee
shall execute, authenticate and deliver, to each beneficial owner identified by
DTC in exchange for its beneficial interest in such Restricted Global
Certificate or Regulation S Global Certificate, as the case may be, an equal
aggregate principal amount of Restricted Definitive Certificates or Regulation S
Definitive Certificates, as the case may be, of authorized denominations. None
of the Company, the Registrar, the Paying Agent nor the Trustee shall be liable
for any delay in delivery of such instructions and may conclusively rely on, and
shall be protected in relying on, such registration instructions. Upon the
issuance of Definitive Certificates, the Trustee shall recognize the Person in
whose name the Definitive Certificates are registered in the Register as
Certificateholders hereunder. Neither the Company nor the Trustee shall be
liable if the Trustee or the Company is unable to locate a qualified successor
clearing agency.

            (e) Any Definitive Certificate delivered in exchange for an interest
in the Restricted Global Certificate pursuant to paragraph (b) of this Section
3.05 shall, except as otherwise provided by paragraph (e) of Section 3.06, bear
the Restricted Legend.
<PAGE>   29
                                      -24-


            (f) Prior to the expiration of the Restricted Period, any Regulation
S Definitive Certificate delivered in exchange for an interest in a Regulation S
Global Certificate pursuant to paragraph (b) of this Section shall bear the
Restricted Legend.

            (g) The registered holder of any Restricted Global Certificate or
Regulation S Global Certificate may grant proxies and otherwise authorize any
Person, including Agent Members and Persons that may hold interests through
Agent Members, to take any action which a Holder is entitled to take under this
Agreement or the Certificates.

            Section 3.06. Special Transfer Provisions. Unless and until (i) an
Initial Certificate is sold under an effective Shelf Registration Statement, or
(ii) an Initial Certificate is exchanged for an Exchange Certificate pursuant to
an effective Exchange Offer Registration Statement, in each case pursuant to the
terms of the Registration Rights Agreement, the following provisions shall apply
to such Initial Certificates:

            (a) Transfers to Non-QIB Institutional Accredited Investors. The
      following provisions shall apply with respect to the registration of any
      proposed transfer of a Certificate to any Institutional Accredited
      Investor which is neither a QIB nor a Non-U.S. Person:

                  (i) The Registrar shall register the transfer of any
            Certificate, whether or not bearing the Restricted Legend, only if
            (x) the requested transfer is at least two years after the later of
            the original issue date of the Certificates and the last date on
            which such Certificate was held by the Company, the Trustee or any
            affiliate of any of such Persons or (y) the proposed transferor is
            an Initial Purchaser who is transferring Certificates purchased
            under the Certificates Purchase Agreement and the proposed
            transferee has delivered to the Registrar a letter substantially in
            the form of Exhibit C hereto and the aggregate principal amount of
            the Certificates being transferred is at least $100,000. Except as
            provided in the foregoing clause (y), the Registrar shall not
            register the transfer of any Certificate to any Institutional
            Accredited Investor which is neither a QIB nor a Non-U.S. Person.

                  (ii) If the proposed transferor is an Agent Member holding a
            beneficial interest in a Restricted Global Certificate, upon receipt
            by the Registrar of (x) the documents, if any, required by paragraph
            (i) and (y) instructions given in accordance with DTC's and the
            Registrar's procedures, the Registrar shall reflect on its books and
            records the date of the transfer and a decrease in the principal
            amount of such Restricted Global Certificate in an amount equal to
            the principal amount of the beneficial interest in such Restricted
            Global Certificate to be transferred, and the Trustee shall execute,
            authenticate and deliver to the transferor or at its direction, one
            or more Restricted Definitive Certificates of like tenor and amount.

            (b) Transfers to QIBs. The following provisions shall apply with
      respect to the registration of any proposed transfer of an Initial
      Certificate to a QIB (excluding Non-U.S. Persons):
<PAGE>   30
                                      -25-



                  (i) If the Certificate to be transferred consists of
            Restricted Definitive Certificates, or of an interest in any
            Regulation S Global Certificate during the Restricted Period, the
            Registrar shall register the transfer if such transfer is being made
            by a proposed transferor who has checked the box provided for on the
            form of Initial Certificate stating, or has otherwise advised the
            Trustee and the Registrar in writing, that the sale has been made in
            compliance with the provisions of Rule 144A to a transferee who has
            signed the certification provided for on the form of Initial
            Certificate stating, or has otherwise advised the Trustee and the
            Registrar in writing, that it is purchasing the Initial Certificate
            for its own account or an account with respect to which it exercises
            sole investment discretion and that it, or the Person on whose
            behalf it is acting with respect to any such account, is a QIB
            within the meaning of Rule 144A, and is aware that the sale to it is
            being made in reliance on Rule 144A and acknowledges that it has
            received such information regarding the Trust and/or the Company as
            it has requested pursuant to Rule 144A or has determined not to
            request such information and that it is aware that the transferor is
            relying upon its foregoing representations in order to claim the
            exemption from registration provided by Rule 144A.

                  (ii) Upon receipt by the Registrar of the documents required
            by clause (i) above and instructions given in accordance with DTC's
            and the Registrar's procedures therefor, the Registrar shall reflect
            on its books and records the date of such transfer and an increase
            in the principal amount of a Restricted Global Certificate in an
            amount equal to the principal amount of the Restricted Definitive
            Certificates or interests in such Regulation S Global Certificate,
            as the case may be, being transferred, and the Trustee shall cancel
            such Definitive Certificates or decrease the amount of such
            Regulation S Global Certificate so transferred.

            (c) Transfers of Interests in the Regulation S Global Certificate or
      Regulation S Definitive Certificates. After the expiration of the
      Restricted Period, the Registrar shall register any transfer of interests
      in any Regulation S Global Certificate or Regulation S Definitive
      Certificates without requiring any additional certification. Until the
      expiration of the Restricted Period, interests in the Regulation S Global
      Certificate may only be held through Agent Members acting for and on
      behalf of Euroclear and Cedel.

            (d) Transfers to Non-U.S. Persons at Any Time. The following
      provisions shall apply with respect to any registration of any transfer of
      an Initial Certificate to a Non-U.S. Person:

                  (i) Prior to the expiration of the Restricted Period, the
            Registrar shall register any proposed transfer of an Initial
            Certificate to a Non-U.S. Person upon receipt of a certificate
            substantially in the form set forth as Exhibit B hereto from the
            proposed transferor.

                  (ii) After the expiration of the Restricted Period, the
            Registrar shall register any proposed transfer to any Non-U.S.
            Person if the Certificate to be transferred is a Restricted
            Definitive Certificate or an interest in a Restricted
<PAGE>   31
                                      -26-


            Global Certificate, upon receipt of a certificate substantially in
            the form of Exhibit B from the proposed transferor. The Registrar
            shall promptly send a copy of such certificate to the Company.

                  (iii) Upon receipt by the Registrar of (x) the documents, if
            any, required by clause (ii) and (y) instructions in accordance with
            DTC's and the Registrar's procedures, the Registrar shall reflect on
            its books and records the date of such transfer and a decrease in
            the principal amount of such Restricted Global Certificate in an
            amount equal to the principal amount of the beneficial interest in
            such Restricted Global Certificate to be transferred, and, upon
            receipt by the Registrar of instructions given in accordance with
            DTC's and the Registrar's procedures, the Registrar shall reflect on
            its books and records the date and an increase in the principal
            amount of the Regulation S Global Certificate in an amount equal to
            the principal amount of the Restricted Definitive Certificate or the
            Restricted Global Certificate, as the case may be, to be
            transferred, and the Trustee shall cancel the Definitive
            Certificate, if any, so transferred or decrease the amount of such
            Restricted Global Certificate.

            (e) Restricted Legend. Upon the transfer, exchange or replacement of
      Certificates not bearing the Restricted Legend, the Registrar shall
      deliver Certificates that do not bear the Restricted Legend. Upon the
      transfer, exchange or replacement of Certificates bearing the Restricted
      Legend, the Registrar shall deliver only Certificates that bear the
      Restricted Legend unless either (i) the circumstances contemplated by
      paragraph (d)(ii) of this Section 3.06 exist or (ii) there is delivered to
      the Registrar an Opinion of Counsel to the effect that neither such legend
      nor the related restrictions on transfer are required in order to maintain
      compliance with the provisions of the Securities Act.

            (f) General. By acceptance of any Certificate bearing the Restricted
      Legend, each Holder of such a Certificate acknowledges the restrictions on
      transfer of such Certificate set forth in this Agreement and agrees that
      it will transfer such Certificate only as provided in this Agreement. The
      Registrar shall not register a transfer of any Certificate unless such
      transfer complies with the restrictions on transfer, if any, of such
      Certificate set forth in this Agreement. In connection with any transfer
      of Certificates, each Certificateholder agrees by its acceptance of the
      Certificates to furnish the Registrar or the Trustee such certifications,
      legal opinions or other information as either of them may reasonably
      require to confirm that such transfer is being made pursuant to an
      exemption from, or a transaction not subject to, the registration
      requirements of the Securities Act and in accordance with the terms and
      provisions of this Article III; provided that the Registrar shall not be
      required to determine the sufficiency of any such certifications, legal
      opinions or other information.

            Until such time as no Certificates remain Outstanding, the Registrar
shall retain copies of all letters, notices and other written communications
received pursuant to Section 3.05 or this Section 3.06. The Trustee, if not the
Registrar at such time, shall have the right to inspect and make copies of all
such letters, notices or other written communications at any reasonable time
upon the giving of reasonable written notice to the Registrar.
<PAGE>   32
                                      -27-


            Section 3.07. Mutilated, Destroyed, Lost or Stolen Certificates. If
(a) any mutilated Certificate is surrendered to the Registrar or the Registrar
receives evidence to its satisfaction of the destruction, loss or theft of any
Certificate and (b) there is delivered to the Registrar and the Trustee such
security, indemnity or bond, as may be required by them to save each of them
harmless, then, in the absence of notice to the Registrar or the Trustee that
such destroyed, lost or stolen Certificate has been acquired by a protected
purchaser, and provided that the requirements of Section 8-405 of the Uniform
Commercial Code in effect in any applicable jurisdiction are met, the Trustee
shall execute, authenticate and deliver, in exchange for or in lieu of any such
mutilated, destroyed, lost or stolen Certificate, a new Certificate or
Certificates, in authorized denominations and of like Fractional Undivided
Interest and bearing a number not contemporaneously outstanding.

            In connection with the issuance of any new Certificate under this
Section 3.07, the Trustee may require the payment of a sum sufficient to cover
any tax or other governmental charge that may be imposed in relation thereto and
any other expenses (including the fees and expenses of the Trustee and the
Registrar) connected therewith.

            Any duplicate Certificate issued pursuant to this Section 3.07 shall
constitute conclusive evidence of the appropriate Fractional Undivided Interest
in the Trust, as if originally issued, whether or not the lost, stolen or
destroyed Certificate shall be found at any time.

            The provisions of this Section are exclusive and shall preclude (to
the extent lawful) all other rights and remedies with respect to the replacement
or payment of mutilated, destroyed, lost or stolen Certificates.

            Section 3.08. Persons Deemed Owners. Prior to due presentment of a
Certificate for registration of transfer, the Trustee, the Registrar and any
Paying Agent may treat the Person in whose name any Certificate is registered
(as of the day of determination) as the owner of such Certificate for the
purpose of receiving distributions pursuant to Article IV and for all other
purposes whatsoever, and none of the Trustee, the Registrar or any Paying Agent
shall be affected by any notice to the contrary.

            Section 3.09. Cancellation. All Certificates surrendered for payment
or transfer or exchange shall, if surrendered to the Trustee or any agent of the
Trustee other than the Registrar, be delivered to the Registrar for cancellation
and shall promptly be canceled by it. No Certificates shall be authenticated in
lieu of or in exchange for any Certificates canceled as provided in this
Section, except as expressly permitted by this Agreement. All canceled
Certificates held by the Registrar shall be destroyed and a certification of
their destruction delivered to the Trustee.

            Section 3.10. Temporary Certificates. Until definitive Certificates
are ready for delivery, the Trustee shall authenticate temporary Certificates.
Temporary Certificates shall be substantially in the form of definitive
Certificates but may have insertions, substitutions, omissions and other
variations determined to be appropriate by the officers executing the temporary
Certificates, as evidenced by their execution of such temporary Certificates. If
temporary Certificates are issued, the Trustee will cause definitive
Certificates to be prepared without unreasonable delay. After the preparation of
definitive Certificates, the temporary
<PAGE>   33
                                      -28-


Certificates shall be exchangeable for definitive Certificates upon surrender of
the temporary Certificates at the office or agency of the Trustee designated for
such purpose pursuant to Section 7.12, without charge to the Certificateholder.
Upon surrender for cancellation of any one or more temporary Certificates, the
Trustee shall execute, authenticate and deliver in exchange therefor a like face
amount of definitive Certificates of authorized denominations. Until so
exchanged, the temporary Certificates shall be entitled to the same benefits
under this Agreement as definitive Certificates.

            Section 3.11. Limitation of Liability for Payments. All payments and
distributions made to Certificateholders in respect of the Certificates shall be
made only from the Trust Property and only to the extent that the Trustee shall
have sufficient income or proceeds from the Trust Property to make such payments
in accordance with the terms of Article IV of this Agreement. Each
Certificateholder, by its acceptance of a Certificate, agrees that it will look
solely to the income and proceeds from the Trust Property for any payment or
distribution due to such Certificateholder pursuant to the terms of this
Agreement and that it will not have any recourse to the Company, the Trustee,
the Loan Trustees, the Liquidity Provider, the Owner Trustees or the Owner
Participants, except as otherwise expressly provided herein or in the
Intercreditor Agreement.

            The Company is a party to this Agreement solely for purposes of
meeting the requirements of the Trust Indenture Act, and therefore shall not
have any right, obligation or liability hereunder (except as otherwise expressly
provided herein).

            Section 3.12 ERISA Restrictive Legend. All Certificates issued
pursuant to this Agreement shall bear a legend to the following effect (the
"ERISA Legend") unless the Company and the Trustee determine otherwise
consistent with applicable law:

            "BY ITS ACQUISITION HEREOF, THE HOLDER REPRESENTS THAT (A) NO PLAN
ASSETS HAVE BEEN USED TO PURCHASE THIS CERTIFICATE OR AN INTEREST HEREIN OR (B)
THE PURCHASE AND HOLDING OF THIS CERTIFICATE OR AN INTEREST HEREIN IS EXEMPT
FROM THE PROHIBITED TRANSACTION RESTRICTIONS OF ERISA AND THE CODE PURSUANT TO
ONE OR MORE PROHIBITED TRANSACTION STATUTORY OR ADMINISTRATIVE EXEMPTIONS. THE
PASS THROUGH TRUST AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO
REFUSE TO REGISTER ANY TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE
FOREGOING RESTRICTIONS."

            By acceptance of any Certificate bearing the ERISA Legend, each
Holder of such a Certificate acknowledges the restrictions on transfer of such
Certificate set forth in this Agreement and agrees that it will transfer such
Certificate only as provided in this Agreement. The Trustee shall not register a
transfer of any Certificate unless such transfer complies with the restrictions
on transfer, if any, of such Certificate set forth in such legend.


                                   ARTICLE IV
<PAGE>   34
                                      -29-


                         DISTRIBUTIONS; STATEMENTS TO
                              CERTIFICATEHOLDERS

            Section 4.01. Certificate Account and Special Payments Account. (a)
The Trustee shall establish and maintain on behalf of the Certificateholders a
Certificate Account as one or more non-interest-bearing accounts. The Trustee
shall hold the Certificate Account in trust for the benefit of the
Certificateholders, and shall make or permit withdrawals therefrom only as
provided in this Agreement. On each day when a Scheduled Payment is made to the
Trustee under the Intercreditor Agreement, the Trustee upon receipt thereof
shall immediately deposit the aggregate amount of such Scheduled Payment in the
Certificate Account.

            (b) The Trustee shall establish and maintain on behalf of the
Certificateholders a Special Payments Account as one or more accounts, which
shall be non-interest bearing except as provided in Section 4.04. The Trustee
shall hold the Special Payments Account in trust for the benefit of the
Certificateholders and shall make or permit withdrawals therefrom only as
provided in this Agreement. On each day when one or more Special Payments are
made to the Trustee under the Intercreditor Agreement and upon the payment of
the Special Redemption Premium to the Trustee under the Note Purchase Agreement,
the Trustee, upon receipt thereof, shall immediately deposit the aggregate
amount of such Special Payments in the Special Payments Account.

            (c) The Trustee shall cause the Subordination Agent to present to
the related Loan Trustee of each Equipment Note such Equipment Note on the date
of its stated final maturity or, in the case of any Equipment Note which is to
be redeemed in whole pursuant to the related Indenture, on the applicable
redemption date under such Indenture.

            Section 4.02. Distributions from Certificate Account and Special
Payments Account. (a) On each Regular Distribution Date or as soon thereafter as
the Trustee has confirmed receipt of the payment of all or any part of the
Scheduled Payments due on such date, the Trustee shall distribute out of the
Certificate Account the entire amount deposited therein pursuant to Section
4.01(a). There shall be so distributed to each Certificateholder of record on
the Record Date with respect to such Regular Distribution Date (other than as
provided in Section 11.01 concerning the final distribution) by check mailed to
such Certificateholder, at the address appearing in the Register, such
Certificateholder's pro rata share (based on the Fractional Undivided Interest
in the Trust held by such Certificateholder) of the total amount in the
Certificate Account, except that, with respect to Certificates registered on the
Record Date in the name of DTC, such distribution shall be made by wire transfer
in immediately available funds to the account designated by DTC.

            (b) On each Special Distribution Date with respect to any Special
Payment or as soon thereafter as the Trustee has confirmed receipt of any
Special Payments due on the Equipment Notes held in the related Trust or
realized upon the sale of such Equipment Notes or receipt of the Special
Redemption Premium, the Trustee shall distribute out of the Special Payments
Account the entire amount of such Special Payment deposited therein pursuant to
Section 4.01(b). There shall be so distributed to each Certificateholder of
record on the Record Date with respect to such Special Distribution Date (other
than as provided in Section 11.01 concerning the final distribution) by check
mailed to such Certificateholder, at the address
<PAGE>   35
                                      -30-


appearing in the Register, such Certificateholder's pro rata share (based on the
Fractional Undivided Interest in the Trust held by such Certificateholder) of
the total amount in the Special Payments Account on account of such Special
Payment, except that, with respect to Certificates registered on the Record Date
in the name of DTC, such distribution shall be made by wire transfer in
immediately available funds to the account designated by DTC.

            (c) The Trustee shall cause notice of each Special Payment to be
mailed to each Certificateholder at his address as it appears in the Register.
In the event of redemption or purchase of Equipment Notes held in the Trust,
such notice shall be mailed not less than 20 days prior to the Special
Distribution Date for the Special Payment resulting from such redemption or
purchase, which Special Distribution Date shall be the date of such redemption
or purchase. In the event of the payment of a Special Redemption Premium by the
Company to the Trustee under the Note Purchase Agreement, such notice shall be
mailed, together with the notice by the Escrow Paying Agent under Section 2.06
of the Escrow Agreement, not less than 20 days prior to the Special Distribution
Date for such amount, which Special Distribution Date shall be the Final
Withdrawal Date. In the case of any other Special Payments, such notice shall be
mailed as soon as practicable after the Trustee has confirmed that it has
received funds for such Special Payment, stating the Special Distribution Date
for such Special Payment which shall occur not less than 20 days after the date
of such notice and as soon as practicable thereafter. Notices mailed by the
Trustee shall set forth:

            (i) the Special Distribution Date and the Record Date therefor
      (except as otherwise provided in Section 11.01),

            (ii) the amount of the Special Payment for each $1,000 face amount
      Certificate and the amount thereof constituting principal, premium, if
      any, and interest,

            (iii) the reason for the Special Payment, and

            (iv) if the Special Distribution Date is the same date as a Regular
      Distribution Date, the total amount to be received on such date for each
      $1,000 face amount Certificate.

If the amount of (i) premium, if any, payable upon the redemption or purchase of
an Equipment Note or (ii) the Special Redemption Premium, if any, has not been
calculated at the time that the Trustee mails notice of a Special Payment, it
shall be sufficient if the notice sets forth the other amounts to be distributed
and states that any premium received will also be distributed.

            If any redemption of the Equipment Notes held in the Trust is
canceled, the Trustee, as soon as possible after learning thereof, shall cause
notice thereof to be mailed to each Certificateholder at its address as it
appears on the Register.

            Section 4.03. Statements to Certificateholders. (a) On each
Distribution Date, the Trustee will include with each distribution to
Certificateholders of a Scheduled Payment or Special Payment, as the case may
be, a statement setting forth the information provided below (in the case of a
Special Payment, including any Special Redemption Premium, reflecting in part
the information provided by the Escrow Paying Agent under the Escrow Agreement).
Such
<PAGE>   36
                                      -31-


statement shall set forth (per $1,000 face amount Certificate as to (ii), (iii),
(iv) and (v) below) the following information:

            (i) the aggregate amount of funds distributed on such Distribution
      Date hereunder and under the Escrow Agreement, indicating the amount
      allocable to each source;

            (ii) the amount of such distribution hereunder allocable to
      principal and the amount allocable to premium (including the Special
      Redemption Premium), if any;

            (iii) the amount of such distribution hereunder allocable to
      interest; and

            (iv) the amount of such distribution under the Escrow Agreement
      allocable to interest;

            (v) the amount of such distribution under the Escrow Agreement
      allocable to Deposits; and

            (vi) the Pool Balance and the Pool Factor.

            With respect to the Certificates registered in the name of DTC, on
the Record Date prior to each Distribution Date, the Trustee will request from
DTC a securities position listing setting forth the names of all Agent Members
reflected on DTC's books as holding interests in the Certificates on such Record
Date. On each Distribution Date, the Trustee will mail to each such Agent Member
the statement described above and will make available additional copies as
requested by such Agent Member for forwarding to holders of interests in the
Certificates.

            (b) Within a reasonable period of time after the end of each
calendar year but not later than the latest date permitted by law, the Trustee
shall furnish to each Person who at any time during such calendar year was a
Certificateholder of record a statement containing the sum of the amounts
determined pursuant to clauses (a)(i), (a)(ii), (a)(iii), (a)(iv) and (a)(v)
above for such calendar year or, in the event such Person was a
Certificateholder of record during a portion of such calendar year, for such
portion of such year, and such other items as are readily available to the
Trustee and which a Certificateholder shall reasonably request as necessary for
the purpose of such Certificateholder's preparation of its federal income tax
returns. Such statement and such other items shall be prepared on the basis of
information supplied to the Trustee by the Agent Members and shall be delivered
by the Trustee to such Agent Members to be available for forwarding by such
Agent Members to the holders of interests in the Certificates in the manner
described in Section 4.03(a).

            (c) Promptly following (i) the Delivery Period Termination Date, if
there has been any change in the information set forth in clauses (x), (y) and
(z) below from that set forth in page 69 of the Offering Circular, and (ii) any
early redemption or purchase of, or any default in the payment of principal or
interest in respect of, any of the Equipment Notes held in the Trust, or any
Final Withdrawal, the Trustee shall furnish to Certificateholders of record on
such date a statement setting forth (x) the expected Pool Balances for each
subsequent Regular Distribution Date following the Delivery Period Termination
Date, (y) the related Pool Factors for such Regular Distribution Dates and (z)
the expected principal distribution schedule of the
<PAGE>   37
                                      -32-


Equipment Notes, in the aggregate, held as Trust Property at the date of such
notice. With respect to the Certificates registered in the name of DTC, on the
Delivery Period Termination Date, the Trustee will request from DTC a securities
position listing setting forth the names of all Agent Members reflected on DTC's
books as holding interests in the Certificates on such date. The Trustee will
mail to each such Agent Member the statement described above and will make
available additional copies as requested by such Agent Member for forwarding to
holders of interests in the Certificates.

            Section 4.04. Investment of Special Payment Moneys. Any money
received by the Trustee pursuant to Section 4.01(b) representing a Special
Payment which is not distributed on the date received shall, to the extent
practicable, be invested in Permitted Investments by the Trustee pending
distribution of such Special Payment pursuant to Section 4.02. Any investment
made pursuant to this Section 4.04 shall be in such Permitted Investments having
maturities not later than the date that such moneys are required to be used to
make the payment required under Section 4.02 on the applicable Special
Distribution Date and the Trustee shall hold any such Permitted Investments
until maturity. The Trustee shall have no liability with respect to any
investment made pursuant to this Section 4.04, other than by reason of the
willful misconduct or negligence of the Trustee. All income and earnings from
such investments shall be distributed on such Special Distribution Date as part
of such Special Payment.


                                    ARTICLE V

                                   THE COMPANY

            Section 5.01. Maintenance of Corporate Existence. The Company, at
its own cost and expense, will do or cause to be done all things necessary to
preserve and keep in full force and effect its corporate existence, except as
permitted by Section 5.02.

            Section 5.02. Consolidation, Merger, etc. The Company shall not
consolidate with or merge into any other corporation or convey, transfer or
lease substantially all of its assets as an entirety to any Person unless:

            (a) the corporation formed by such consolidation or into which the
      Company is merged or the Person that acquires by conveyance, transfer or
      lease substantially all of the assets of the Company as an entirety shall
      be (i) organized and validly existing under the laws of the United States
      of America or any state thereof or the District of Columbia, (ii) a
      "citizen of the United States" as defined in 49 U.S.C. 40102(a)(15), as
      amended, and (iii) a United States certificated air carrier, if and so
      long as such status is a condition of entitlement to the benefits of
      Section 1110 of the Bankruptcy Reform Act of 1978, as amended (11 U.S.C.
      Section 1110);

            (b) the corporation formed by such consolidation or into which the
      Company is merged or the Person which acquires by conveyance, transfer or
      lease substantially all of the assets of the Company as an entirety shall
      execute and deliver to the Trustee a duly authorized, valid, binding and
      enforceable agreement in form and substance reasonably satisfactory to the
      Trustee containing an assumption by such successor corporation or Person
      of the due and punctual performance and observance of each covenant and
<PAGE>   38
                                      -33-


      condition of this Agreement, the Other Pass Through Trust Agreements and
      each Financing Document to be performed or observed by the Company; and

            (c) the Company shall have delivered to the Trustee an Officer's
      Certificate of the Company reasonably satisfactory to the Trustee, stating
      that such consolidation, merger, conveyance, transfer or lease and the
      assumption agreement mentioned in clause (b) above comply with this
      Section 5.02 and that all conditions precedent herein provided for
      relating to such transaction have been complied with.

            Upon any consolidation or merger, or any conveyance, transfer or
lease of substantially all of the assets of the Company as an entirety in
accordance with this Section 5.02, the successor corporation or Person formed by
such consolidation or into which the Company is merged or to which such
conveyance, transfer or lease is made shall succeed to, and be substituted for,
and may exercise every right and power of, the Company under this Agreement with
the same effect as if such successor corporation or Person had been named as the
Company herein. No such conveyance, transfer or lease of substantially all of
the assets of the Company as an entirety shall have the effect of releasing any
successor corporation or Person which shall have become such in the manner
prescribed in this Section 5.02 from its liability in respect of this Agreement
and any Financing Document to which it is a party.


                                   ARTICLE VI

                                     DEFAULT

            Section 6.01. Events of Default. (a) Exercise of Remedies. Upon the
occurrence and during the continuation of any Indenture Default under any
Indenture, the Trustee may, to the extent it is the Controlling Party at such
time (as determined pursuant to the Intercreditor Agreement), direct the
exercise of remedies as provided in the Intercreditor Agreement.

            (b) Purchase Rights of Certificateholders. (i) At any time after the
      occurrence and during the continuance of a Triggering Event, each
      Certificateholder shall have the right (which shall not expire upon any
      purchase of the Class A Certificates pursuant to the Class B Trust
      Agreement) to purchase, for the purchase prices set forth in the Class A
      Trust Agreement and the Class B Trust Agreement, respectively, all, but
      not less than all, of the Class A Certificates and the Class B
      Certificates upon ten days' written notice to the Class A Trustee, the
      Class B Trustee and each other Certificateholder, provided that (i) if
      prior to the end of such ten-day period any other Certificateholder
      notifies such purchasing Certificateholder that such other
      Certificateholder wants to participate in such purchase, then such other
      Certificateholder may join with the purchasing Certificateholder to
      purchase all, but not less than all, of the Class A Certificates and the
      Class B Certificates pro rata based on the Fractional Undivided Interest
      in the Trust held by each such Certificateholder and (ii) if prior to the
      end of such ten-day period any other Certificateholder fails to notify the
      purchasing Certificateholder of such other Certificateholder's desire to
      participate in such a purchase, then such other Certificateholder shall
      lose its right to purchase the Class A Certificates and the Class B
      Certificates pursuant to this Section 6.01(b); and
<PAGE>   39
                                      -34-


            (ii) by acceptance of its Certificate, each Certificateholder agrees
      that at any time after the occurrence and during the continuation of a
      Triggering Event, each Class D Certificateholder shall have the right
      (which shall not expire upon any purchase of the Class A Certificates
      pursuant to the Class B Trust Agreement or any purchase of the Class A
      Certificates and the Class B Certificates pursuant to clause (b)(i) above)
      to purchase all, but not less than all, of the Class A Certificates, the
      Class B Certificates and the Certificates upon ten days' written notice to
      the Class A Trustee, the Class B Trustee, the Trustee and each other Class
      D Certificateholder, provided that (A) if prior to the end of such ten-day
      period any other Class D Certificateholder notifies such purchasing Class
      D Certificateholder that such other Class D Certificateholder wants to
      participate in such purchase, then such other Class D Certificateholder
      may join with the purchasing Class D Certificateholder to purchase all,
      but not less than all, of the Class A Certificates, the Class B
      Certificates and the Certificates pro rata based on the Fractional
      Undivided Interest in the Class D Trust, taken as a whole, held by each
      such Class D Certificateholder and (B) if prior to the end of such ten day
      period any other Class D Certificateholder fails to notify the purchasing
      Class D Certificateholder of such other Class D Certificateholder's desire
      to participate in such a purchase, then such other Class D
      Certificateholder shall lose its right to purchase the Certificates
      pursuant to this Section 6.01(b).

            The purchase price with respect to the Certificates shall be equal
to the Pool Balance of the Certificates, together with accrued and unpaid
interest thereon to the date of such purchase, without premium, but including
any other amounts then due and payable to the Certificateholders under this
Agreement, the Intercreditor Agreement, the Escrow Agreement or any Financing
Document or on or in respect of the Certificates; provided, however, that (i) if
such purchase occurs after the record date specified in Section 2.03(b) of the
Escrow Agreement relating to the distribution of unused Deposits and accrued and
unpaid interest thereunder, such purchase price shall be reduced by the
aggregate amount of unused Deposits and interest to be distributed under the
Escrow Agreement (which deducted amounts shall remain distributable to, and may
be retained by, the Certificateholder as of such Record Date) and (ii) if such
purchase occurs after a Record Date, such purchase price shall be reduced by the
amount to be distributed hereunder on the related Distribution Date (which
deducted amounts shall remain distributable to, and may be retained by, the
Certificateholder as of such Record Date); provided, further, that no such
purchase of Certificates shall be effective unless the purchaser(s) shall
certify to the Trustee that contemporaneously with such purchase, such
purchaser(s) is purchasing, pursuant to the terms of this Agreement and the
Other Pass Through Trust Agreements, the Class A Certificates, the Class B
Certificates and the Certificates which are senior to the securities held by
such purchaser(s). Each payment of the purchase price of the Certificates
referred to in the first sentence hereof shall be made to an account or accounts
designated by the Trustee and each such purchase shall be subject to the terms
of this Section 6.01(b). Each Certificateholder agrees by its acceptance of its
Certificate that it will, subject to Section 3.04 hereof, upon payment from such
Class D Certificateholder(s), of the purchase price set forth in the first
sentence of this paragraph, forthwith sell, assign, transfer and convey to the
purchaser(s) thereof (without recourse, representation or warranty of any kind
except for its own acts), all of the right, title, interest and obligation of
such Certificateholder in this Agreement, the Escrow Agreement, the Deposit
Agreement, the Intercreditor Agreement, the Liquidity Facility, the Financing
Documents and all Certificates and Escrow Receipts held by such
Certificateholder (excluding
<PAGE>   40
                                      -35-


all right, title and interest under any of the foregoing to the extent such
right, title or interest is with respect to an obligation not then due and
payable as respects any action or inaction or state of affairs occurring prior
to such sale) and the purchaser shall assume all of such Certificateholder's
obligations under this Agreement, the Escrow Agreement, the Deposit Agreement,
the Intercreditor Agreement, the Liquidity Facility, the Financing Documents and
all such Certificates and Escrow Receipts. The Certificates will be deemed to be
purchased on the date payment of the purchase price is made notwithstanding the
failure of the Certificateholders to deliver any Certificates (whether in the
form of Definitive Certificates or beneficial interests in Global Certificates)
and, upon such a purchase, (i) the only rights of the Certificateholders will be
to deliver the Certificates to the purchaser(s) and receive the purchase price
for such Certificates and (ii) if the purchaser(s) shall so request, such
Certificateholder will comply with all the provisions of Section 3.04 hereof to
enable new Certificates to be issued to the purchaser in such denominations as
it shall request. All charges and expenses in connection with the issuance of
any such new Certificates shall be borne by the purchaser thereof.

            As used in this Section 6.01(b), the terms "Class A Certificate",
"Class A Certificateholder", "Class A Trust", "Class A Trust Agreement", "Class
A Trustee", "Class B Certificate", "Class B Certificateholder", "Class B Trust",
"Class B Trust Agreement", "Class B Trustee", "Class D Certificate", and "Class
D Trust", shall have the respective meanings assigned to such terms in the
Intercreditor Agreement.

            Section 6.02. Incidents of Sale of Equipment Notes. Upon any sale of
all or any part of the Equipment Notes made either under the power of sale given
under this Agreement or otherwise for the enforcement of this Agreement, the
following shall be applicable:

            (1) Certificateholders and Trustee May Purchase Equipment Notes. Any
      Certificateholder, the Trustee in its individual or any other capacity or
      any other Person may bid for and purchase any of the Equipment Notes, and
      upon compliance with the terms of sale, may hold, retain, possess and
      dispose of such Equipment Notes in their own absolute right without
      further accountability.

            (2) Receipt of Trustee Shall Discharge Purchaser. The receipt of the
      Trustee making such sale shall be a sufficient discharge to any purchaser
      for his purchase money, and, after paying such purchase money and
      receiving such receipt, such purchaser or its personal representative or
      assigns shall not be obliged to see to the application of such purchase
      money, or be in any way answerable for any loss, misapplication or
      non-application thereof.

            (3) Application of Moneys Received upon Sale. Any moneys collected
      by the Trustee upon any sale made either under the power of sale given by
      this Agreement or otherwise for the enforcement of this Agreement shall be
      applied as provided in Section 4.02.

            Section 6.03. Judicial Proceedings Instituted by Trustee; Trustee
May Bring Suit. If there shall be a failure to make payment of the principal of,
premium, if any, or interest on any Equipment Note, or if there shall be any
failure to pay Rent (as defined in the relevant Lease) under any Lease when due
and payable, then the Trustee, in its own name and as trustee
<PAGE>   41
                                      -36-


of an express trust, as holder of such Equipment Notes, to the extent permitted
by and in accordance with the terms of the Intercreditor Agreement and the
Financing Documents (subject to the rights of the applicable Owner Trustee or
Owner Participant to cure any such failure to pay principal of, premium, if any,
or interest on any Equipment Note or to pay Rent under any Lease in accordance
with the applicable Indenture), shall be entitled and empowered to institute any
suits, actions or proceedings at law, in equity or otherwise, for the collection
of the sums so due and unpaid on such Equipment Notes or under such Lease and
may prosecute any such claim or proceeding to judgment or final decree with
respect to the whole amount of any such sums so due and unpaid.

            Section 6.04 Control by Certificateholders. Subject to Section 6.03
and the Intercreditor Agreement, the Certificateholders holding Certificates
evidencing Fractional Undivided Interests aggregating not less than a majority
in interest in the Trust shall have the right to direct the time, method and
place of conducting any proceeding for any remedy available to the Trustee with
respect to the Trust or pursuant to the terms of the Intercreditor Agreement, or
exercising any trust or power conferred on the Trustee under this Agreement or
the Intercreditor Agreement, including any right of the Trustee as Controlling
Party under the Intercreditor Agreement or as holder of the Equipment Notes,
provided that:

            (1) such Direction shall not be in conflict with any rule of law or
      with this Agreement and would not involve the Trustee in personal
      liability or expense,

            (2) the Trustee shall not determine that the action so directed
      would be unjustly prejudicial to the Certificateholders not taking part in
      such Direction, and

            (3) the Trustee may take any other action deemed proper by the
      Trustee which is not inconsistent with such Direction.

            Section 6.05. Waiver of Past Defaults. Subject to the Intercreditor
Agreement, the Certificateholders holding Certificates evidencing Fractional
Undivided Interests aggregating not less than a majority in interest in the
Trust (i) may on behalf of all of the Certificateholders waive any past Event of
Default hereunder and its consequences or (ii) if the Trustee is the Controlling
Party, may direct the Trustee to instruct the applicable Loan Trustee to waive
any past Indenture Default under any Indenture and its consequences, and thereby
annul any Direction given by such Certificateholders or the Trustee to such Loan
Trustee with respect thereto, except a default:

            (1) in the deposit of any Scheduled Payment or Special Payment under
      Section 4.01 or in the distribution of any payment under Section 4.02 on
      the Certificates, or

            (2) in the payment of the principal of (premium, if any) or interest
      on the Equipment Notes, or

            (3) in respect of a covenant or provision hereof which under Article
      IX cannot be modified or amended without the consent of each
      Certificateholder holding an Outstanding Certificate affected thereby.
<PAGE>   42
                                      -37-


            Upon any such waiver, such default shall cease to exist with respect
to the Certificates and any Event of Default arising therefrom shall be deemed
to have been cured for every purpose and any direction given by the Trustee on
behalf of the Certificateholders to the relevant Loan Trustee shall be annulled
with respect thereto; but no such waiver shall extend to any subsequent or other
default or Event of Default or impair any right consequent thereon. Upon any
such waiver, the Trustee shall vote the Equipment Notes issued under the
relevant Indenture to waive the corresponding Indenture Default.

            Section 6.06. Right of Certificateholders to Receive Payments Not to
Be Impaired. Anything in this Agreement to the contrary notwithstanding,
including, without limitation, Section 6.07 hereof, but subject to the
Intercreditor Agreement, the right of any Certificateholder to receive
distributions of payments required pursuant to Section 4.02 hereof on the
Certificates when due, or to institute suit for the enforcement of any such
payment on or after the applicable Regular Distribution Date or Special
Distribution Date, shall not be impaired or affected without the consent of such
Certificateholder.

            Section 6.07. Certificateholders May Not Bring Suit Except Under
Certain Conditions. A Certificateholder shall not have the right to institute
any suit, action or proceeding at law or in equity or otherwise with respect to
this Agreement, for the appointment of a receiver or for the enforcement of any
other remedy under this Agreement, unless:

            (1) such Certificateholder previously shall have given written
      notice to the Trustee of a continuing Event of Default;

            (2) Certificateholders holding Certificates evidencing Fractional
      Undivided Interests aggregating not less than 25% of the Trust shall have
      requested the Trustee in writing to institute such action, suit or
      proceeding and shall have offered to the Trustee indemnity as provided in
      Section 7.03(e);

            (3) the Trustee shall have refused or neglected to institute such an
      action, suit or proceeding for 60 days after receipt of such notice,
      request and offer of indemnity; and

            (4) no direction inconsistent with such written request shall have
      been given to the Trustee during such 60-day period by Certificateholders
      holding Certificates evidencing Fractional Undivided Interests aggregating
      not less than a majority in interest in the Trust.

            It is understood and intended that no one or more of the
Certificateholders shall have any right in any manner whatsoever hereunder or
under the Certificates to (i) surrender, impair, waive, affect, disturb or
prejudice any property in the Trust Property or the lien of any Indenture on any
property subject thereto, or the rights of the Certificateholders or the holders
of the Equipment Notes, (ii) obtain or seek to obtain priority over or
preference with respect to any other such Certificateholder or (iii) enforce any
right under this Agreement, except in the manner herein provided and for the
equal, ratable and common benefit of all the Certificateholders subject to the
provisions of this Agreement.

            Section 6.08. Remedies Cumulative. Every remedy given hereunder to
the Trustee or to any of the Certificateholders shall not be exclusive of any
other remedy or
<PAGE>   43
                                      -38-


remedies, and every such remedy shall be cumulative and in addition to every
other remedy given hereunder or now or hereafter given by statute, law, equity
or otherwise.


                                   ARTICLE VII

                                   THE TRUSTEE

            Section 7.01. Certain Duties and Responsibilities. (a) Except during
the continuance of an Event of Default, the Trustee undertakes to perform such
duties as are specifically set forth in this Agreement, and no implied covenants
or obligations shall be read into this Agreement against the Trustee.

            (b) In case an Event of Default has occurred and is continuing, the
Trustee shall exercise such of the rights and powers vested in it by this
Agreement, and use the same degree of care and skill in their exercise, as a
prudent man would exercise or use under the circumstances in the conduct of its
own affairs.

            (c) No provision of this Agreement shall be construed to relieve the
Trustee from liability for its own negligent action, its own negligent failure
to act, or its own willful misconduct, except that

            (1) this SubSection shall not be construed to limit the effect of
      SubSection (a) of this Section; and

            (2) the Trustee shall not be liable for any error of judgment made
      in good faith by a Responsible Officer of the Trustee, unless it shall be
      proved that the Trustee was negligent in ascertaining the pertinent facts.

            (d) Whether or not herein expressly so provided, every provision of
this Trust Agreement relating to the conduct or affecting the liability of or
affording protection to the Trustee shall be subject to the provisions of this
Section.

            Section 7.02. Notice of Defaults. As promptly as practicable after,
and in any event within 90 days after, the occurrence of any default (as such
term is defined below) hereunder, the Trustee shall transmit by mail to the
Company, the Owner Trustees, the Owner Participants, the Loan Trustees and the
Certificateholders in accordance with Section 313(c) of the Trust Indenture Act,
notice of such default hereunder known to the Trustee, unless such default shall
have been cured or waived; provided, however, that, except in the case of a
default on the payment of the principal, premium, if any, or interest on any
Equipment Note held in the Trust, the Trustee shall be protected in withholding
such notice if and so long as the board of directors, the executive committee or
a trust committee of directors and/or Responsible Officers of the Trustee in
good faith determine that the withholding of such notice is in the interests of
the Certificateholders. For the purpose of this Section, the term "default"
means any event that is, or after notice or lapse of time or both would become,
an Event of Default.

            Section 7.03. Certain Rights of Trustee. Subject to the provisions
of Section 315 of the Trust Indenture Act:
<PAGE>   44
                                      -39-


            (a) the Trustee may rely and shall be protected in acting or
      refraining from acting in reliance upon any resolution, certificate,
      statement, instrument, opinion, report, notice, request, direction,
      consent, order, bond, debenture or other paper or document believed by it
      to be genuine and to have been signed or presented by the proper party or
      parties;

            (b) any request or direction of the Company mentioned herein shall
      be sufficiently evidenced by a written description of the subject matter
      thereof accompanied by an Officer's Certificate and an Opinion of Counsel
      as provided in Section 1.02 of this Agreement;

            (c) whenever in the administration of this Agreement the Trustee
      shall deem it desirable that a matter be proved or established prior to
      taking, suffering or omitting any action hereunder, the Trustee (unless
      other evidence be herein specifically prescribed) may, in the absence of
      bad faith on its part, rely upon an Officer's Certificate of the Company,
      any Owner Trustee or any Loan Trustee;

            (d) the Trustee may consult with counsel and the advice of such
      counsel or any Opinion of Counsel shall be full and complete authorization
      and protection in respect of any action taken, suffered or omitted by it
      hereunder in good faith and in reliance thereon;

            (e) the Trustee shall be under no obligation to exercise any of the
      rights or powers vested in it by this Agreement at the Direction of any of
      the Certificateholders pursuant to this Agreement, unless such
      Certificateholders shall have offered to the Trustee reasonable security
      or indemnity against the cost, expenses and liabilities which might be
      incurred by it in compliance with such Direction;

            (f) the Trustee shall not be bound to make any investigation into
      the facts or matters stated in any resolution, certificate, statement,
      instrument, opinion, report, notice, request, direction, consent, order,
      bond, debenture or other paper or document;

            (g) the Trustee may execute any of the trusts or powers under this
      Agreement or perform any duties under this Agreement either directly or by
      or through agents or attorneys, and the Trustee shall not be responsible
      for any misconduct or negligence on the part of any agent or attorney
      appointed with due care by it under this Agreement;

            (h) the Trustee shall not be liable with respect to any action taken
      or omitted to be taken by it in good faith in accordance with the
      Direction of the Certificateholders holding Certificates evidencing
      Fractional Undivided Interests aggregating not less than a majority in
      interest in the Trust relating to the time, method and place of conducting
      any proceeding for any remedy available to the Trustee, or exercising any
      trust or power conferred upon the Trustee, under this Agreement; and

            (i) the Trustee shall not be required to expend or risk its own
      funds in the performance of any of its duties under this Agreement, or in
      the exercise of any of its rights or powers, if it shall have reasonable
      grounds for believing that repayment of such funds or adequate indemnity
      against such risk is not reasonably assured to it.
<PAGE>   45
                                      -40-


            Section 7.04. Not Responsible for Recitals or Issuance of
Certificates. The recitals contained herein and in the Certificates, except the
certificates of authentication, shall not be taken as the statements of the
Trustee, and the Trustee assumes no responsibility for their correctness.
Subject to Section 7.15, the Trustee makes no representations as to the validity
or sufficiency of this Agreement, any Equipment Notes, the Intercreditor
Agreement, the Deposit Agreement, the Escrow Agreement, the Certificates or any
other Financing Document, except that the Trustee hereby represents and warrants
that this Agreement has been, and the Intercreditor Agreement, the Registration
Rights Agreement, the Note Purchase Agreement, the Escrow Agreement and each
Certificate will be, executed, authenticated and delivered by one of its
officers who is duly authorized to execute, authenticate and deliver such
document on its behalf.

            Section 7.05. May Hold Certificates. The Trustee, any Paying Agent,
Registrar or any of their Affiliates or any other agent in their respective
individual or any other capacity may become the owner or pledgee of Certificates
and, subject to Sections 310(b) and 311 of the Trust Indenture Act, if
applicable, may otherwise deal with the Company, the Owner Trustees or the Loan
Trustees with the same rights it would have if it were not Trustee, Paying
Agent, Registrar or such other agent.

            Section 7.06. Money Held in Trust. Money held by the Trustee or the
Paying Agent in trust hereunder need not be segregated from other funds except
to the extent required herein or by law and neither the Trustee nor the Paying
Agent shall have any liability for interest upon any such moneys except as
provided for herein.

            Section 7.07. Compensation and Reimbursement. The Company agrees:

            (1) to pay, or cause to be paid, to the Trustee from time to time
      reasonable compensation for all services rendered by it hereunder as set
      forth in a written fee letter dated the date hereof between the Company
      and the Trustee, which letter is incorporated herein by reference (which
      compensation shall not be limited by any provision of law in regard to the
      compensation of a trustee of an express trust);

            (2) except as otherwise expressly provided herein, to reimburse, or
      cause to be reimbursed, the Trustee upon its request for all reasonable
      out-of-pocket expenses, disbursements and advances incurred or made by the
      Trustee in accordance with any provision of this Agreement (including the
      reasonable compensation and the expenses and disbursements of its agents
      and counsel), except any such expense, disbursement or advance as may be
      attributable to its undertaking its normal administrative functions, or
      its negligence, willful misconduct or bad faith or as may be incurred due
      to the Trustee's breach of its representations and warranties set forth in
      Section 7.15; and

            (3) to indemnify, or cause to be indemnified, the Trustee for, and
      to hold it harmless against, any loss, liability, expense or Tax (other
      than for or with respect to any Unindemnified Tax) incurred without
      negligence, willful misconduct or bad faith, on its part, arising out of
      or in connection with the acceptance or administration of this Trust,
      including the costs and expenses of defending itself against any claim or
      liability in connection with the exercise or performance of any of its
      powers or duties hereunder,
<PAGE>   46
                                      -41-


      except for any such loss, liability or expense incurred by reason of the
      Trustee's breach of its covenants hereunder or under any Financing
      Document to which it is a party or its representations and warranties set
      forth in Section 7.15 or in any other Financing Document, the
      authorization or giving or withholding of any future amendments,
      supplements, waivers or consents with respect hereto or any of the
      Financing Documents, which amendments, supplements, waivers or consents
      are not required pursuant to the terms of the Financing Documents and not
      requested by the Company, any loss of tax benefits, any Unindemnified Tax,
      or increase in tax liability under any tax law whether or not the Company
      is required to indemnify thereof or pursuant to this Agreement or any
      costs associated with overhead or normal administration hereunder or any
      voluntary resignation pursuant to Section 7.09.

            With respect to paragraph (3) above, the Trustee shall notify the
Company promptly of any claim for which it may seek indemnity and the Company
shall make payment on any such claim within 30 days of written demand thereof
(delivered together with supporting documentation). The Company shall defend the
claim and the Trustee shall cooperate in the defense. The Trustee may have
separate counsel with the consent of the Company and the Company will pay the
reasonable fees and expenses of such counsel. The Company need not pay for any
settlement made, in settlement or otherwise, without its consent.

            With respect to any Tax other than an Unindemnified Tax, the Trustee
shall be entitled to reimbursement from, and shall have a lien prior to the
Certificates upon, the Trust Property for any such Tax incurred without
negligence, bad faith or willful misconduct, on its part, arising out of or in
connection with the acceptance or administration of such Trust (other than any
Tax attributable to the Trustee's compensation for serving as such), including
any costs and expenses incurred in contesting the imposition of any such Tax. If
the Trustee reimburses itself from the Trust Property of such Trust for any such
Tax, it will mail a brief report within 30 days setting forth the circumstances
thereof to all Certificateholders as their names and addresses appear in the
Register.

            Section 7.08. Corporate Trustee Required; Eligibility. There shall
at all times be a Trustee hereunder which shall be eligible to act as a trustee
under Section 310(a) of the Trust Indenture Act and shall have a combined
capital and surplus of at least $75,000,000 (or a combined capital and surplus
in excess of $5,000,000 and the obligations of which, whether now in existence
or hereafter incurred, are fully and unconditionally guaranteed by a corporation
organized and doing business under the laws of the United States, any state or
territory thereof or of the District of Columbia and having a combined capital
and surplus of at least $75,000,000). If such corporation publishes reports of
conditions at least annually, pursuant to law or to the requirements of federal,
state, territorial or District of Columbia supervising or examining authority,
then for the purposes of this Section 7.08, the combined capital and surplus of
such corporation shall be deemed to be its combined capital and surplus as set
forth in its most recent report of conditions so published.

            In case at any time the Trustee shall cease to be eligible in
accordance with the provisions of this Section 7.08 to act as Trustee, the
Trustee shall resign immediately as Trustee in the manner and with the effect
specified in Section 7.09.
<PAGE>   47
                                      -42-


            Section 7.09 Resignation and Removal; Appointment of Successor. (a)
No resignation or removal of the Trustee and no appointment of a successor
Trustee pursuant to this Article shall become effective until the acceptance of
appointment by the successor Trustee under Section 7.10.

            (b) The Trustee may resign at any time as trustee by giving prior
written notice thereof to the Company, the Authorized Agents, the Owner Trustees
and the Loan Trustees. If an instrument of acceptance by a successor Trustee
shall not have been delivered to the Company, the Authorized Agents, the Owner
Trustees, the Loan Trustees and the Trustee within 30 days after the giving of
such notice of resignation, the resigning Trustee may petition any court of
competent jurisdiction for the appointment of a successor Trustee.

            (c) The Trustee may be removed at any time by Direction of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not less than a majority in interest in the Trust
delivered to the Trustee and to the Company, the Owner Trustees and the Loan
Trustees.

            (d) If at any time:

            (1) the Trustee shall fail to comply with Section 310 of the Trust
      Indenture Act, if applicable, after written request therefor by the
      Company or by any Certificateholder who has been a bona fide
      Certificateholder for at least six months; or

            (2) the Trustee shall cease to be eligible under Section 7.08 and
      shall fail to resign after written request therefor by the Company or by
      any such Certificateholder; or

            (3) the Trustee shall become incapable of acting or shall be
      adjudged a bankrupt or insolvent or a receiver of the Trustee or of its
      property shall be appointed or any public officer shall take charge or
      control of the Trustee or of its property or affairs for the purpose of
      rehabilitation, conservation or liquidation;

then, in any case, (i) the Company may remove the Trustee or (ii) any
Certificateholder who has been a bona fide Certificateholder for at least six
months may, on behalf of itself and all others similarly situated, petition any
court of competent jurisdiction for the removal of the Trustee and the
appointment of a successor Trustee.

            (e) If a Responsible Officer of the Trustee shall obtain actual
knowledge of an Avoidable Tax which has been or is likely to be asserted, the
Trustee shall promptly notify the Company and shall, within 30 days of such
notification, resign hereunder unless within such 30-day period the Trustee
shall have received notice that the Company has agreed to pay such tax. The
Company shall promptly appoint a successor Trustee in a jurisdiction where there
are no Avoidable Taxes.

            (f) If the Trustee shall resign, be removed or become incapable of
acting or if a vacancy shall occur in the office of the Trustee for any cause,
the Company shall promptly appoint a successor Trustee. If, within one year
after such resignation, removal or incapability, or other occurrence of such
vacancy, a successor Trustee shall be appointed by Direction of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not
<PAGE>   48
                                      -43-


less than a majority in interest in the Trust delivered to the Company, the
Owner Trustees, the Loan Trustees and the retiring Trustee, and the Company
approves such appointment, which approval shall not be unreasonably withheld,
then the successor Trustee so appointed shall, forthwith upon its acceptance of
such appointment, become the successor Trustee and supersede the successor
Trustee appointed as provided above. If no successor Trustee shall have been so
appointed as provided above and accepted appointment in the manner hereinafter
provided, any Certificateholder who has been a bona fide Certificateholder for
at least six months may, on behalf of himself and all others similarly situated,
petition any court of competent jurisdiction for the appointment of a successor
Trustee.

            (g) The successor Trustee shall give notice of the resignation and
removal of the Trustee and appointment of the successor Trustee by mailing
written notice of such event by first-class mail, postage prepaid, to the
Certificateholders as their names and addresses appear in the Register. Each
notice shall include the name of such successor Trustee and the address of its
Corporate Trust Office.

            Section 7.10. Acceptance of Appointment by Successor. Every
successor Trustee appointed hereunder shall execute and deliver to the Company,
the Authorized Agents, the Owner Trustees and the Loan Trustees and to the
retiring Trustee an instrument accepting such appointment, and thereupon the
resignation or removal of the retiring Trustee shall become effective and such
successor Trustee, without any further act, deed or conveyance, shall become
vested with all the rights, powers, trusts and duties of the retiring Trustee;
but, on request of the Company or the successor Trustee, such retiring Trustee
shall execute and deliver an instrument transferring to such successor Trustee
all such rights, powers and trusts of the retiring Trustee and shall duly
assign, transfer and deliver to such successor Trustee all Trust Property held
by such retiring Trustee hereunder, subject nevertheless to its lien, if any,
provided for in Section 7.07. Upon request of any such successor Trustee, the
Company, the retiring Trustee and such successor Trustee shall execute and
deliver any and all instruments containing such provisions as shall be necessary
or desirable to transfer and confirm to, and for more fully and certainly
vesting in, such successor Trustee all such rights, powers and trusts.

            No institution shall accept its appointment as a Trustee hereunder
unless at the time of such acceptance such institution shall be qualified and
eligible under this Article VII.

            Section 7.11. Merger, Conversion, Consolidation or Succession to
Business. Any corporation into which the Trustee may be merged or converted or
with which it may be consolidated, or any corporation resulting from any merger,
conversion or consolidation to which the Trustee shall be a party, or any
corporation succeeding to all or substantially all of the corporate trust
business of the Trustee, shall be the successor of the Trustee hereunder,
provided such corporation shall be otherwise qualified and eligible under this
Article VII, without the execution or filing of any paper or any further act on
the part of any of the parties hereto. In case any Certificates shall have been
executed or authenticated, but not delivered, by the Trustee then in office, any
successor by merger, conversion or consolidation to such authenticating Trustee
may adopt such execution or authentication and deliver the Certificates so
executed or authenticated with the same effect as if such successor Trustee had
itself executed or authenticated such Certificates.
<PAGE>   49
                                      -44-


            Section 7.12. Maintenance of Agencies. (a) There shall at all times
be maintained an office or agency in the location set forth in Section 12.03
where Certificates may be presented or surrendered for registration of transfer
or for exchange, and for payment thereof and where notices and demands to or
upon the Trustee in respect of such certificates or this Agreement may be
served; provided, however, that, if it shall be necessary that the Trustee
maintain an office or agency in another location (e.g., the Certificates shall
be represented by Definitive Certificates and shall be listed on a national
securities exchange), the Trustee will make all reasonable efforts to establish
such an office or agency. Written notice of the location of each such other
office or agency and of any change of location thereof shall be given by the
Trustee to the Company, the Owner Trustees, the Loan Trustees (in the case of
any Owner Trustee or Loan Trustee, at its address specified in the Financing
Documents or such other address as may be notified to the Trustee) and the
Certificateholders. In the event that no such office or agency shall be
maintained or no such notice of location or of change of location shall be
given, presentations and demands may be made and notices may be served at the
Corporate Trust Office of the Trustee.

            (b) There shall at all times be a Registrar and a Paying Agent
hereunder with respect to the Certificates. Each such Authorized Agent shall be
a bank or trust company, shall be a corporation organized and doing business
under the laws of the United States or any state, with a combined capital and
surplus of at least $75,000,000, or, if the Trustee shall be acting as the
Registrar or Paying Agent hereunder, a corporation having a combined capital and
surplus in excess of $5,000,000, the obligations of which are guaranteed by a
corporation organized and doing business under the laws of the United States or
any state, with a combined capital and surplus of at least $75,000,000, and
shall be authorized under such laws to exercise corporate trust powers, subject
to supervision by Federal or state authorities. The Trustee shall initially be
the Paying Agent and, as provided in Section 3.04, Registrar hereunder with
respect to the Certificates. Each Registrar shall furnish to the Trustee, at
stated intervals of not more than six months, and at such other times as the
Trustee may request in writing, a copy of the Register maintained by such
Registrar.

            (c) Any corporation into which any Authorized Agent may be merged or
converted or with which it may be consolidated, or any corporation resulting
from any merger, consolidation or conversion to which any Authorized Agent shall
be a party, or any corporation succeeding to the corporate trust business of any
Authorized Agent, shall be the successor of such Authorized Agent hereunder, if
such successor corporation is otherwise eligible under this Section, without the
execution or filing of any paper or any further act on the part of the parties
hereto or such Authorized Agent or such successor corporation.

            (d) Any Authorized Agent may at any time resign by giving written
notice of resignation to the Trustee, the Company, the Owner Trustees and the
Loan Trustees. The Company may, and at the request of the Trustee shall, at any
time terminate the agency of any Authorized Agent by giving written notice of
termination to such Authorized Agent and to the Trustee. Upon the resignation or
termination of an Authorized Agent or in case at any time any such Authorized
Agent shall cease to be eligible under this Section (when, in either case, no
other Authorized Agent performing the functions of such Authorized Agent shall
have been appointed), the Company shall promptly appoint one or more qualified
successor Authorized Agents, reasonably satisfactory to the Trustee, to perform
the functions of the Authorized Agent
<PAGE>   50
                                      -45-


which has resigned or whose agency has been terminated or who shall have ceased
to be eligible under this Section. The Company shall give written notice of any
such appointment made by it to the Trustee, the Owner Trustees and the Loan
Trustees; and in each case the Trustee shall mail notice of such appointment to
all Certificateholders as their names and addresses appear on the Register.

            (e) The Company agrees to pay, or cause to be paid, from time to
time to each Authorized Agent reasonable compensation for its services and to
reimburse it for its reasonable expenses as set forth in the letter agreement
referred to in Section 7.07 hereof.

            Section 7.13. Money for Certificate Payments to Be Held in Trust.
All moneys deposited with any Paying Agent for the purpose of any payment on
Certificates shall be deposited and held in trust for the benefit of the
Certificateholders entitled to such payment, subject to the provisions of this
Section. Moneys so deposited and held in trust shall constitute a separate trust
fund for the benefit of the Certificateholders with respect to which such money
was deposited.

            The Trustee may at any time, for the purpose of obtaining the
satisfaction and discharge of this Agreement or for any other purpose, direct
any Paying Agent to pay to the Trustee all sums held in trust by such Paying
Agent, such sums to be held by the Trustee upon the same trusts as those upon
which such sums were held by such Paying Agent; and, upon such payment by any
Paying Agent to the Trustee, such Paying Agent shall be released from all
further liability with respect to such money.

            Section 7.14. Registration of Equipment Notes in Name of
Subordination Agent. The Trustee agrees that all Equipment Notes to be purchased
by the Trust shall be issued in the name of the Subordination Agent or its
nominee and held by the Subordination Agent in trust for the benefit of the
Certificateholders, or, if not so held, the Subordination Agent or its nominee
shall be reflected as the owner of such Equipment Notes in the register of the
issuer of such Equipment Notes.

            Section 7.15. Representations and Warranties of Trustee. The Trustee
hereby represents and warrants that:

            (a) the Trustee is a Delaware banking corporation organized and
validly existing in good standing under the laws of the State of Delaware;

            (b) the Trustee has full power, authority and legal right to
execute, deliver, and perform this Agreement, the Intercreditor Agreement, the
Registration Rights Agreement, the Escrow Agreement, the Note Purchase Agreement
and the Financing Documents to which it is a party and has taken all necessary
action to authorize the execution, delivery, and performance by it of this
Agreement, the Intercreditor Agreement, the Registration Rights Agreement, the
Escrow Agreement, the Note Purchase Agreement and the Financing Documents to
which it is a party;

            (c) the execution, delivery and performance by the Trustee of this
Agreement, the Intercreditor Agreement, the Registration Rights Agreement, the
Escrow Agreement, the Note Purchase Agreement and the Financing Documents to
which it is a party (i) will not violate
<PAGE>   51
                                      -46-


any provision of United States federal law or the law of the state of the United
States where it is located governing the banking and trust powers of the Trustee
or any order, writ, judgment, or decree of any court, arbitrator or governmental
authority applicable to the Trustee or any of its assets, (ii) will not violate
any provision of the articles of association or by-laws of the Trustee, or (iii)
will not violate any provision of, or constitute, with or without notice or
lapse of time, a default under, or result in the creation or imposition of any
lien on any properties included in the Trust Property pursuant to the provisions
of any mortgage, indenture, contract, agreement or other undertaking to which it
is a party, which violation, default or lien could reasonably be expected to
have an adverse effect on the Trustee's performance or ability to perform its
duties hereunder or thereunder or on the transactions contemplated herein or
therein;

            (d) the execution, delivery and performance by the Trustee of this
Agreement, the Intercreditor Agreement, the Registration Rights Agreement, the
Escrow Agreement, the Note Purchase Agreement, and the Financing Documents to
which it is a party will not require the authorization, consent, or approval of,
the giving of notice to, the filing or registration with, or the taking of any
other action in respect of, any governmental authority or agency of the United
States or the state of the United States where it is located regulating the
banking and corporate trust activities of the Trustee; and

            (e) this Agreement, the Intercreditor Agreement, the Registration
Rights Agreement, the Escrow Agreement, the Note Purchase Agreement, and the
Financing Documents to which it is a party have been duly executed and delivered
by the Trustee and constitute the legal, valid, and binding agreements of the
Trustee, enforceable against it in accordance with their respective terms,
provided that enforceability may be limited by (i) applicable bankruptcy,
insolvency, reorganization, moratorium or similar laws affecting the rights of
creditors generally and (ii) general principles of equity, regardless of whether
applied in a proceeding in equity or at law.

            Section 7.16. Withholding Taxes, Information Reporting. The Trustee,
as trustee of the grantor trust created by this Agreement, shall exclude and
withhold from each distribution of principal, premium, if any, and interest and
other amounts due under this Agreement or under the Certificates any and all
withholding taxes applicable thereto as required by law. In addition, the
Trustee shall remit such amounts as would be required by Section 1446 of the
Internal Revenue Code of 1986, as amended, if the Trust were characterized as a
partnership engaged in a U.S. trade or business for U.S. federal income tax
purposes and shall withhold such amounts from amounts distributable to or for
the benefit of Certificateholders or Investors that are not United States
persons within the meaning of Section 7701(a)(30) of the Internal Revenue Code
of 1986, as amended. In this regard, the Trustee shall cause the appropriate
withholding agent to withhold with respect to such distributions in the manner
contemplated by Section 10.04 of Revenue Procedure 89-31 and Treasury Regulation
1.1445-8(b)(3) by filing a notice with the National Association of Securities
Dealers, Inc. substantially in the form of Exhibit E hereto on or before the
date 10 days prior to the Record Date. The Trustee shall mail such notice to the
National Association of Securities Dealers no later than the date than 15 days
prior to the Record Date. Investors that are not United States Persons agree to
furnish a United States taxpayer identification number ("TIN") to the Trustee
and the Trustee shall provide such TINs to the appropriate withholding agent.
The Trustee agrees to act as such withholding agent (except to the extent
contemplated above with respect to withholding amounts
<PAGE>   52
                                      -47-


as if the Trust were characterized as a partnership engaged in a U.S. trade or
business for U.S. federal income tax purposes) and, in connection therewith,
whenever any present or future taxes or similar charges are required to be
withheld with respect to any amounts payable in respect of the Certificates, to
withhold such amounts and timely pay the same to the appropriate authority in
the name of and on behalf of the Certificateholders, that it will file any
necessary withholding tax returns or statements when due, and that, as promptly
as possible after the payment thereof, it will deliver to each such
Certificateholder appropriate documentation showing the payment thereof,
together with such additional documentary evidence as such Certificateholders
may reasonably request from time to time. The Trustee agrees to file any other
information reports as it may be required to file under United States law. Each
Certificateholder or Investor that is not a United States person within the
meaning of Section 7701(a)(30) of the Internal Revenue Code, as amended, by its
acceptance of a Certificate or a beneficial interest therein, agrees to
indemnify and hold harmless the Trust and the Trustee from and against any
improper failure to withhold taxes from amounts payable to it or for its
benefit, other than an improper failure attributable to the gross negligence or
willful misconduct of the Trustee.

            Section 7.17. Trustee's Liens. The Trustee in its individual
capacity agrees that it will at its own cost and expense promptly take any
action as may be necessary to duly discharge and satisfy in full any mortgage,
pledge, lien, charge, encumbrance, security interest or claim ("Trustee's
Liens") on or with respect to the Trust Property which is attributable to the
Trustee either (i) in its individual capacity and which is unrelated to the
transactions contemplated by this Agreement, the Intercreditor Agreement, the
Note Purchase Agreement or the Financing Documents, or (ii) as Trustee hereunder
or in its individual capacity and which arises out of acts or omissions on the
part of the Trustee which are not contemplated by this Agreement.

            Section 7.18. Preferential Collection of Claims. The Trustee shall
comply with Section 311(a) of the Trust Indenture Act, excluding any creditor
relationship listed in Section 311(b) of the Trust Indenture Act. If the Trustee
shall resign or be removed as Trustee, it shall be subject to Section 311(a) of
the Trust Indenture Act to the extent provided therein.


                                  ARTICLE VIII

                CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE

            Section 8.01. The Company to Furnish Trustee with Names and
Addresses of Certificateholders. The Company will furnish to the Trustee within
15 days after each Record Date with respect to a Scheduled Payment, and at such
other times as the Trustee may request in writing within 30 days after receipt
by the Company of any such request, a list, in such form as the Trustee may
reasonably require, of all information in the possession or control of the
Company as to the names and addresses of the Certificateholders, in each case as
of a date not more than 15 days prior to the time such list is furnished;
provided, however, that so long as the Trustee is the sole Registrar, no such
list need be furnished; and provided further, however, that no such list need be
furnished for so long as a copy of the Register is being furnished to the
Trustee pursuant to Section 7.12.
<PAGE>   53
                                      -48-


            Section 8.02. Preservation of Information; Communications to
Certificateholders. The Trustee shall preserve, in as current a form as is
reasonably practicable, the names and addresses of Certificateholders contained
in the most recent list furnished to the Trustee as provided in Section 7.12 or
Section 8.01, as the case may be, and the names and addresses of
Certificateholders received by the Trustee in its capacity as Registrar, if so
acting. The Trustee may destroy any list furnished to it as provided in Section
7.12 or Section 8.01, as the case may be, upon receipt of a new list so
furnished.

            Section 8.03. Reports by Trustee. Within 60 days after May 15 of
each year commencing with the first full year following the issuance of the
Certificates, the Trustee shall transmit to the Certificateholders, as provided
in Section 313(c) of the Trust Indenture Act, a brief report dated as of such
May 15, if required by Section 313(a) of the Trust Indenture Act.

            Section 8.04. Reports by the Company. The Company shall:

            (a) file with the Trustee, within 30 days after the Company is
      required to file the same with the SEC, copies of the annual reports and
      of the information, documents and other reports (or copies of such
      portions of any of the foregoing as the SEC may from time to time by rules
      and regulations prescribe) which the Company is required to file with the
      SEC pursuant to Section 13 or Section 15(d) of the Securities Exchange Act
      of 1934, as amended; or, if the Company is not required to file
      information, documents or reports pursuant to either of such sections,
      then to file with the Trustee and the SEC, in accordance with rules and
      regulations prescribed by the SEC, such of the supplementary and periodic
      information, documents and reports which may be required pursuant to
      Section 13 of the Securities Exchange Act of 1934, as amended, in respect
      of a security listed and registered on a national securities exchange as
      may be prescribed in such rules and regulations;

            (b) during any period, prior to the consummation of the Exchange
      Offer and during which the Shelf Registration Statement is not in effect,
      in which the Company is not subject to Section 13(a), 13(c) or 15(d) under
      the Securities Exchange Act of 1934, make available to any Holder of the
      Certificates in connection with any sale thereof and any prospective
      purchaser of the Certificates from such Holder, in each case upon request,
      the information specified in, and meeting the requirements of, Rule
      144A(d)(4) under the Securities Act but only for so long as any of the
      Certificates remain outstanding and are "restricted securities" within the
      meaning of Rule 144(a)(3) under the Securities Act and, in any event, only
      until the second anniversary of the Issuance Date;

            (c) file with the Trustee and the SEC, in accordance with the rules
      and regulations prescribed by the SEC, such additional information,
      documents and reports with respect to compliance by the Company with the
      conditions and covenants provided for in this Agreement, as may be
      required by such rules and regulations, including, in the case of annual
      reports, if required by such rules and regulations, certificates or
      opinions of independent public accountants, conforming to the requirements
      of Section 1.02;

            (d) transmit to all Certificateholders, in the manner and to the
      extent provided in Section 313(c) of the Trust Indenture Act such
      summaries of any information,
<PAGE>   54
                                      -49-


      documents and reports required to be filed by the Company pursuant to
      subsections (a) and (c) of this Section 8.04 as may be required by rules
      and regulations prescribed by the SEC; and

            (e) furnish to the Trustee, not less often than annually, a brief
      certificate from the principal executive officer, principal financial
      officer, any Vice President (or more senior ranking officer) or the
      principal accounting officer as to his or her knowledge of the Company's
      compliance with all conditions and covenants under this Agreement (it
      being understood that for purposes of this paragraph (e), such compliance
      shall be determined without regard to any period of grace or requirement
      of notice provided under this Agreement).


                                   ARTICLE IX

                             SUPPLEMENTAL AGREEMENTS

            Section 9.01. Supplemental Agreements Without Consent of
Certificateholders. Without the consent of the Certificateholders, the Company
may (but will not be required to), and the Trustee (subject to Section 9.03)
shall, at the Company's request, at any time and from time to time, enter into
one or more agreements supplemental hereto or, if applicable, to the
Intercreditor Agreement, the Escrow Agreement, the Note Purchase Agreement, the
Deposit Agreement, the Registration Rights Agreement or any Liquidity Facility
in form satisfactory to the Trustee, for any of the following purposes:

            (1) to evidence the succession of another corporation to the Company
      and the assumption by any such successor of the covenants of the Company
      herein contained or of the Company's obligations under the Note Purchase
      Agreement, the Registration Rights Agreement or any Liquidity Facility; or

            (2) to add to the covenants of the Company for the benefit of the
      Certificateholders, or to surrender any right or power conferred upon the
      Company in this Agreement, the Note Purchase Agreement, the Registration
      Rights Agreement or any Liquidity Facility; or

            (3) to correct or supplement any provision in this Agreement, the
      Intercreditor Agreement, the Escrow Agreement, the Deposit Agreement, the
      Note Purchase Agreement, the Registration Rights Agreement or any
      Liquidity Facility which may be defective or inconsistent with any other
      provision herein or therein or to cure any ambiguity or correct any
      mistake or to modify any other provision with respect to matters or
      questions arising under this Agreement, the Escrow Agreement, the Deposit
      Agreement, the Note Purchase Agreement, the Intercreditor Agreement, the
      Registration Rights Agreement or any Liquidity Facility, provided that any
      such action shall not materially adversely affect the interests of the
      Certificateholders; or

            (4) to comply with any requirement of the SEC, any applicable law,
      rules or regulations of any exchange or quotation system on which the
      Certificates are listed, any
<PAGE>   55
                                      -50-


      regulatory body or the Registration Rights Agreement to effectuate the
      Exchange Offer; or

            (5) to modify, eliminate or add to the provisions of this Agreement
      to such extent as shall be necessary to continue the qualification of this
      Agreement (including any supplemental agreement) under the Trust Indenture
      Act or under any similar Federal statute hereafter enacted, and to add to
      this Agreement such other provisions as may be expressly permitted by the
      Trust Indenture Act, excluding, however, the provisions referred to in
      Section 316(a)(2) of the Trust Indenture Act as in effect at the date as
      of which this instrument was executed or any corresponding provision in
      any similar Federal statute hereafter enacted; or

            (6) to evidence and provide for the acceptance of appointment under
      this Agreement by the Trustee of a successor Trustee and to add to or
      change any of the provisions of this Agreement as shall be necessary to
      provide for or facilitate the administration of the Trust, pursuant to the
      requirements of Section 7.10; or

            (7) to provide the information required under Section 7.12 and
      Section 12.03 as to the Trustee; or

            (8) to modify or eliminate provisions relating to the transfer or
      exchange of Exchange Certificates or the Initial Certificates upon
      consummation of the Exchange Offer (as defined in the Registration Rights
      Agreement) or effectiveness of the Shelf Registration Statement or the
      Exchange Offer Registration Statement;

provided, however, that no such supplemental agreement shall adversely affect
the status of any Trust as a grantor trust under Subpart E, Part I of Subchapter
J of Chapter 1 of Subtitle A of the Internal Revenue Code of 1986, as amended,
for U.S. federal income tax purposes.

            Section 9.02. Supplemental Agreements with Consent of
Certificateholders. With the consent of the Certificateholders holding
Certificates (including consents obtained in connection with a tender offer or
exchange offer for the Certificates) evidencing Fractional Undivided Interests
aggregating not less than a majority in interest in the Trust, by Direction of
said Certificateholders delivered to the Company and the Trustee, the Company
may (with the consent of the Owner Trustees, if any, which consent shall not be
unreasonably withheld), and the Trustee (subject to Section 9.03) shall, enter
into an agreement or agreements for the purpose of adding any provisions to or
changing in any manner or eliminating any of the provisions of this Agreement,
the Intercreditor Agreement, any Liquidity Facility, the Registration Rights
Agreement, the Escrow Agreement, the Deposit Agreement or the Note Purchase
Agreement to the extent applicable to such Certificateholders or of modifying in
any manner the rights and obligations of such Certificateholders under this
Agreement, the Intercreditor Agreement, any Liquidity Facility, the Registration
Rights Agreement, the Escrow Agreement, the Deposit Agreement or the Note
Purchase Agreement to the extent applicable to such Certificateholders or of
modifying in any manner the rights and obligations of such Certificateholders
under this Agreement, the Intercreditor Agreement, any Liquidity Facility, the
Registration Rights Agreement, the Escrow Agreement, the Deposit Agreement or
the Note Purchase Agreement;
<PAGE>   56
                                      -51-


provided, however, that no such agreement shall, without the consent of the
Certificateholder of each Outstanding Certificate affected thereby:

            (1) reduce in any manner the amount of, or delay the timing of, any
      receipt by the Trustee (or, with respect to the Deposits, the
      Certificateholders) of payments on the Equipment Notes held in the Trust
      or on the Deposits or distributions that are required to be made herein on
      any Certificate, or change any date of payment on any Certificate, or
      change the place of payment where, or the coin or currency in which, any
      Certificate is payable, or impair the right to institute suit for the
      enforcement of any such payment or distribution on or after the Regular
      Distribution Date or Special Distribution Date applicable thereto; or

            (2) permit the disposition of any Equipment Note included in the
      Trust Property except as permitted by this Agreement, or otherwise deprive
      such Certificateholder of the benefit of the ownership of the Equipment
      Notes in the Trust; or

            (3) reduce the specified percentage of the aggregate Fractional
      Undivided Interests of the Trust which is required for any such
      supplemental agreement, or reduce such specified percentage required for
      any waiver of compliance with certain provisions of this Agreement or
      certain defaults hereunder and their consequences provided for in this
      Agreement; or

            (4) waive, amend or modify Section 2.4, 3.2 or 3.3 of the
      Intercreditor Agreement in a manner adverse to the Certificateholders; or

            (5) modify any of the provisions of this Section 9.02 or Section
      6.05, except to increase any such percentage or to provide that certain
      other provisions of this Agreement cannot be modified or waived without
      the consent of the Certificateholder of each Certificate affected thereby;
      or

            (6) adversely affect the status of any Trust as a grantor trust
      under Subpart E, Part I of Subchapter J of Chapter 1 of Subtitle A of the
      Internal Revenue Code of 1986, as amended, for U.S. federal income tax
      purposes.

            It shall not be necessary for any Direction of Certificateholders
under this Section to approve the particular form of any proposed supplemental
agreement, but it shall be sufficient if such Direction shall approve the
substance thereof.

            Section 9.03. Documents Affecting Immunity or Indemnity. Except for
the performance of its covenants herein, if in the opinion of the Trustee any
document required to be executed by it pursuant to the terms of Section 9.01 or
9.02 affects adversely any interest, right, duty, immunity or indemnity in favor
of the Trustee under this Agreement, the Trustee may in its discretion decline
to execute such document.

            Section 9.04. Execution of Supplemental Agreements. In executing, or
accepting the additional trusts created by, any agreement permitted by this
Article or the modifications thereby of the trusts created by this Agreement,
the Trustee shall be entitled to
<PAGE>   57
                                      -52-


receive, and shall be fully protected in relying upon, an Opinion of Counsel
stating that the execution of such supplemental agreement is authorized or
permitted by this Agreement.

            Section 9.05. Effect of Supplemental Agreements. Upon the execution
of any agreement supplemental to this Agreement under this Article, this
Agreement shall be modified in accordance therewith, and such supplemental
agreement shall form a part of this Agreement for all purposes; and every Holder
of a Certificate theretofore or thereafter authenticated and delivered hereunder
shall be bound thereby.

            Section 9.06. Conformity with Trust Indenture Act. Every
supplemental agreement executed pursuant to this Article shall conform to the
requirements of the Trust Indenture Act as then in effect.

            Section 9.07. Reference in Certificates to Supplemental Agreements.
Certificates authenticated and delivered after the execution of any supplemental
agreement pursuant to this Article may bear a notation in form approved by the
Trustee as to any matter provided for in such supplemental agreement; and, in
such case, suitable notation may be made upon Outstanding Certificates after
proper presentation and demand.


                                    ARTICLE X

                AMENDMENTS TO INDENTURES AND FINANCING DOCUMENTS

            Section 10.01. Amendments and Supplements to Indentures and
Financing Documents. In the event that the Trustee, as holder (or beneficial
owner through the Subordination Agent) of any Equipment Note in trust for the
benefit of the Certificateholders or as Controlling Party under the
Intercreditor Agreement, receives (directly or indirectly through the
Subordination Agent) a request for a consent to any amendment, modification,
waiver or supplement under any Indenture, any other Financing Document, any
Equipment Note or any other related document, the Trustee shall forthwith send a
notice of such proposed amendment, modification, waiver or supplement to each
Certificateholder registered on the Register as of the date of such notice. The
Trustee shall request from the Certificateholders a Direction as to (a) whether
or not to take or refrain from taking (or direct the Subordination Agent to take
or refrain from taking) any action which a holder of such Equipment Note has the
option to direct, (b) whether or not to give or execute (or direct the
Subordination Agent to give or execute) any waivers, consents, amendments,
modifications or supplements as a holder of such Equipment Note or a Controlling
Party and (c) how to vote (or direct the Subordination Agent to vote) any
Equipment Note if a vote has been called for with respect thereto. Provided such
a request for Certificateholder Direction shall have been made, in directing any
action or casting any vote or giving any consent as the holder of any Equipment
Note (or in directing the Subordination Agent in any of the foregoing), (i)
other than as Controlling Party, the Trustee shall vote for or give consent to
any such action with respect to such Equipment Note in the same proportion as
that of (A) the aggregate face amounts of all Certificates actually voted in
favor of or for giving consent to such action by such Direction of
Certificateholders to (B) the aggregate face amount of all Outstanding
Certificates and (ii) as Controlling Party, the Trustee shall vote as directed
in such Certificateholder Direction by the Certificateholders evidencing a
Fractional Undivided Interest aggregating not less than a majority in interest
in the Trust. For purposes of the immediately
<PAGE>   58
                                      -53-


preceding sentence, a Certificate shall have been "actually voted" if the Holder
of such Certificate has delivered to the Trustee an instrument evidencing such
Holder's consent to such Direction prior to two Business Days before the Trustee
directs such action or casts such vote or gives such consent. Notwithstanding
the foregoing, but subject to Section 6.04 and the Intercreditor Agreement, the
Trustee may, in its own discretion and at its own direction, consent and notify
the relevant Loan Trustee of such consent (or direct the Subordination Agent to
consent and notify the Loan Trustee of such consent) to any amendment,
modification, waiver or supplement under the relevant Indenture, any other
Financing Document, any Equipment Note or any other related document, if an
Event of Default hereunder shall have occurred and be continuing, or if such
amendment, modification, waiver or supplement will not materially adversely
affect the interests of the Certificateholders.


                                   ARTICLE XI

                              TERMINATION OF TRUST

            Section 11.01. Termination of the Trust. The respective obligations
and responsibilities of the Company and the Trustee with respect to the Trust
shall terminate upon the earlier of (A) the completion of the assignment,
transfer and discharge described in the first sentence of the immediately
following paragraph and (B) distribution to all Holders of Certificates and the
Trustee of all amounts required to be distributed to them pursuant to this
Agreement and the disposition of all property held as part of the Trust
Property; provided, however, that in no event shall the Trust continue beyond
one hundred ten (110) years following the date of the earliest execution of this
Trust Agreement.

            Upon the earlier of (i) the first Business Day after November 30,
1999, or, if later, the fifth Business Day following the Delivery Period
Termination Date and (ii) the fifth Business Day following the date on which a
Triggering Event occurs (such date, the "Transfer Date"), or, if later the date
on which all of the conditions set forth in the immediately following sentence
have been satisfied, the Trustee is hereby directed (subject only to the
immediately following sentence) to, and the Company shall direct the institution
that will serve as the Related Trustee under the Related Pass Through Trust
Agreement to, execute and deliver the Assignment and Assumption Agreement,
pursuant to which the Trustee shall assign, transfer and deliver all of the
Trustee's right, title and interest to the Trust Property to the Related Trustee
under the Related Pass Through Trust Agreement. The Trustee and the Related
Trustee shall execute and deliver the Assignment and Assumption Agreement upon
the satisfaction of the following conditions:

            (i) The Trustee, the Related Trustee and each of the Rating Agencies
      then rating the Certificates shall have received an Officer's Certificate
      and an Opinion of Counsel dated the date of the Assignment and Assumption
      Agreement and each satisfying the requirements of Section 1.02, which
      Opinion of Counsel shall be substantially to the effect set forth below
      and may be relied upon by the Beneficiaries (as defined in the Assignment
      and Assumption Agreement):

            (a)   upon the execution and delivery thereof by the parties thereto
                  in accordance with the terms of this Agreement and the Related
                  Pass Through Trust Agreement, the Assignment and Assumption
                  Agreement
<PAGE>   59
                                      -54-


                  will constitute the valid and binding obligation of each of
                  the parties thereto enforceable against each such party in
                  accordance with its terms;

            (b)   upon the execution and delivery of the Assignment and
                  Assumption Agreement in accordance with the terms of this
                  Agreement and the Related Pass Through Trust Agreement, each
                  of the Certificates then Outstanding will be entitled to the
                  benefits of the Related Pass Through Trust Agreement;

            (c)   the Related Trust is not required to be registered as an
                  investment company under the Investment Company Act of 1940,
                  as amended;

            (d)   the Related Pass Through Trust Agreement constitutes the valid
                  and binding obligation of the Company enforceable against the
                  Company in accordance with its terms; and

            (e)   neither the execution and delivery of the Assignment and
                  Assumption Agreement in accordance with the terms of this
                  Agreement and the Related Pass Through Trust Agreement, nor
                  the consummation by the parties thereto of the transactions
                  contemplated to be consummated thereunder on the date
                  thereof, will violate any law or governmental rule or
                  regulation of the State of New York or the United States of
                  America known to such counsel to be applicable to the
                  transactions contemplated by the Assignment and Assumption
                  Agreement.

            (ii) The Trustee and the Company shall have received (x) a copy of
      the articles of incorporation and bylaws of the Related Trustee certified
      as of the Transfer Date by the Secretary or Assistant Secretary of such
      institution and (y) a copy of the filing (including all attachments
      thereto) made by the institution serving as the Related Trustee with the
      Office of the Superintendent, State of New York Banking Department for the
      qualification of the Related Trustee under Section 131(3) of the New York
      Banking Law.

Upon the execution of the Assignment and Assumption Agreement by the parties
thereto, the Trust shall be terminated, the Certificateholders shall receive
beneficial interests in the Related Trust in exchange for their interests in the
Trust equal to their respective beneficial interests in the Trust, and the
Outstanding Certificates representing Fractional Undivided Interests in the
Trust shall be deemed for all purposes of this Agreement and the Related Pass
Through Trust Agreement, without further signature or action of any party or
Certificateholder, to be certificates representing the same fractional undivided
interests in the Related Trust and its trust property. By acceptance of its
Certificate, each Certificateholder consents to such assignment, transfer and
delivery of the Trust Property to the trustee of the Related Trust upon the
execution and delivery of the Assignment and Assumption Agreement.

            In connection with the occurrence of the event set forth in clause
(B) above, notice of such termination, specifying the Distribution Date upon
which the Certificateholders may surrender their Certificates to the Trustee for
payment of the final distribution and cancellation, shall be mailed promptly by
the Trustee to Certificateholders not earlier than the
<PAGE>   60
                                      -55-


60th day and not later than the 20th day next preceding such final Distribution
Date specifying (A) the Distribution Date upon which the proposed final payment
of the Certificates will be made upon presentation and surrender of Certificates
at the office or agency of the Trustee therein specified, (B) the amount of any
such proposed final payment, and (C) that the Record Date otherwise applicable
to such Distribution Date is not applicable, payments being made only upon
presentation and surrender of the Certificates at the office or agency of the
Trustee therein specified. The Trustee shall give such notice to the Registrar
at the time such notice is given to Certificateholders. Upon presentation and
surrender of the Certificates in accordance with such notice, the Trustee shall
cause to be distributed to Certificateholders such final payments.

            In the event that all of the Certificateholders shall not surrender
their Certificates for cancellation within six months after the date specified
in the above-mentioned written notice, the Trustee shall give a second written
notice to the remaining Certificateholders to surrender their Certificates for
cancellation and receive the final distribution with respect thereto. No
additional interest shall accrue on the Certificates after the Distribution Date
specified in the first written notice. In the event that any money held by the
Trustee for the payment of distributions on the Certificates shall remain
unclaimed for two years (or such lesser time as the Trustee shall be satisfied,
after sixty days' notice from the Company, is one month prior to the escheat
period provided under applicable law) after the final distribution date with
respect thereto, the Trustee shall pay to each Loan Trustee the appropriate
amount of money relating to such Loan Trustee and shall give written notice
thereof to the related Owner Trustees, the Owner Participants and the Company.


                                   ARTICLE XII

                            MISCELLANEOUS PROVISIONS

            Section 12.01. Limitation on Rights of Certificateholders. The death
or incapacity of any Certificateholder shall not operate to terminate this
Agreement or the Trust, nor entitle such Certificateholder's legal
representatives or heirs to claim an accounting or to take any action or
commence any proceeding in any court for a partition or winding up of the Trust,
nor otherwise affect the rights, obligations, and liabilities of the parties
hereto or any of them.

            Section 12.02. Certificates Nonassessable and Fully Paid. Except as
set forth in the last sentence of this Section 12.02, Certificateholders shall
not be personally liable for obligations of the Trust, the Fractional Undivided
Interests represented by the Certificates shall be nonassessable for any losses
or expenses of the Trust or for any reason whatsoever, and Certificates, upon
authentication thereof by the Trustee pursuant to Section 3.03, are and shall be
deemed fully paid. No Certificateholder shall have any right (except as
expressly provided herein) to vote or in any manner otherwise control the
operation and management of the Trust Property, the Trust, or the obligations of
the parties hereto, nor shall anything set forth herein, or contained in the
terms of the Certificates, be construed so as to constitute the
Certificateholders from time to time as partners or members of an association.
Neither the existence of the Trust nor any provision herein is intended to or
shall limit the liability the Certificateholders would otherwise incur if the
Certificateholders owned Trust Property as co-owners, or incurred any
obligations of the Trust, directly rather than through the Trust.
<PAGE>   61
                                      -56-


            Section 12.03. Notices. (a) Unless otherwise specifically provided
herein, all notices required under the terms and provisions of this Agreement
shall be in English and in writing, and any such notice may be given by United
States mail, courier service or telecopy, and any such notice shall be effective
when received or, if made, given, furnished or filed by facsimile or
telecommunication transmission, when received unless received outside of
business hours, in which case on the next open of business on a Business Day,

            if to the Company, to:

                  America West Airlines, Inc.
                  4000 East Sky Harbor Boulevard
                  Phoenix, Arizona  85043

                  Attention:  Vice President-
                              Treasurer
                  Facsimile:  (602) 693-5886


            if to the Trustee, to:

                  Wilmington Trust Company
                  Rodney Square North
                  1100 North Market Street
                  Wilmington, Delaware  19890-0001

                  Attention:  Corporate Trust Department
                  Facsimile:  (302) 651-8882
                  Telephone:   (302) 651-8584

            (b) The Company or the Trustee, by notice to the other, may
designate additional or different addresses for subsequent notices or
communications.

            (c) Any notice or communication to Certificateholders shall be
mailed by first-class mail to the addresses for Certificateholders shown on the
Register kept by the Registrar. Failure so to mail a notice or communication or
any defect in such notice or communication shall not affect its sufficiency with
respect to other Certificateholders.

            (d) If a notice or communication is mailed in the manner provided
above within the time prescribed, it is conclusively presumed to have been duly
given, whether or not the addressee receives it.

            (e) If the Company mails a notice or communication to the
Certificateholders, it shall mail a copy to the Trustee and to the Paying Agent
at the same time.

            (f) Notwithstanding the foregoing, all communications or notices
to the Trustee shall be deemed to be given only when received by a Responsible
Officer of the Trustee.
<PAGE>   62
                                      -57-


            (g) The Trustee shall promptly furnish the Company with a copy of
any demand, notice or written communication received by the Trustee hereunder
from any Certificateholder, Owner Trustee or Loan Trustee.

            Section 12.04. Governing Law. THIS AGREEMENT HAS BEEN DELIVERED IN
THE STATE OF DELAWARE AND THIS AGREEMENT AND THE CERTIFICATES SHALL BE GOVERNED
BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF DELAWARE AND THE
OBLIGATIONS, RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER SHALL BE DETERMINED IN
ACCORDANCE WITH SUCH LAWS.

            Section 12.05. Severability of Provisions. If any one or more of the
covenants, agreements, provisions or terms of this Agreement shall be for any
reason whatsoever held invalid, then such covenants, agreements, provisions, or
terms shall be deemed severable from the remaining covenants, agreements,
provisions or terms of this Agreement and shall in no way affect the validity or
enforceability of the other provisions of this Agreement or the Trust, or of the
Certificates or the rights of the Certificateholders thereof.

            Section 12.06. Trust Indenture Act Controls. Upon the occurrence of
any Registration Event, this Agreement shall become subject to the provisions of
the Trust Indenture Act and shall, to the extent applicable, be governed by such
provisions. From and after any Registration Event, if any provision of this
Agreement limits, qualifies or conflicts with another provision which is
required to be included in this Agreement by the Trust Indenture Act, the
required provision shall control.

            Section 12.07. Effect of Headings and Table of Contents. The Article
and Section headings herein and the Table of Contents are for convenience only
and shall not affect the construction hereof.

            Section 12.08. Successors and Assigns. All covenants, agreements,
representations and warranties in this Agreement by the Trustee and the Company
shall bind and, to the extent permitted hereby, shall inure to the benefit of
and be enforceable by their respective successors and assigns, whether so
expressed or not.

            Section 12.09. Benefits of Agreement. Nothing in this Agreement or
in the Certificates, express or implied, shall give to any Person, other than
the parties hereto and their successors hereunder, and the Certificateholders,
any benefit or any legal or equitable right, remedy or claim under this
Agreement.

            Section 12.10. Legal Holidays. In any case where any Regular
Distribution Date or Special Distribution Date relating to any Certificate shall
not be a Business Day, then (notwithstanding any other provision of this
Agreement) payment need not be made on such date, but may be made on the next
succeeding Business Day with the same force and effect as if made on such
Regular Distribution Date or Special Distribution Date, and no interest shall
accrue during the intervening period.

            Section 12.11. Counterparts. For the purpose of facilitating the
execution of this Agreement and for other purposes, this Agreement may be
executed simultaneously in any
<PAGE>   63
                                      -58-


number of counterparts, each of which counterparts shall be deemed to be an
original, and all of which counterparts shall constitute but one and the same
instrument.

            Section 12.12. Intention of Parties. The parties hereto intend that
the Trust be classified for U.S. federal income tax purposes as a grantor trust
under Subpart E, Part I of Subchapter J of the Internal Revenue Code of 1986, as
amended, and not as a trust or association taxable as a corporation or as a
partnership. Each Certificateholder and Investor, by its acceptance of its
Certificate or a beneficial interest therein, agrees to treat the Trust as a
grantor trust for all U.S. federal, state and local income tax purposes. The
powers granted and obligations undertaken pursuant to this Agreement shall be so
construed so as to further such intent.
<PAGE>   64
                                      -59-


            IN WITNESS WHEREOF, the parties have caused this Agreement to be
duly executed by their respective officers thereunto duly authorized as of the
day and year first written above.


                                    AMERICA WEST AIRLINES, INC.


                                    By: /s/ W. Douglas Parker
                                       -----------------------------------
                                        Name: W. Douglas Parker
                                        Title: Sr. Vice President & CFO


                                    WILMINGTON TRUST COMPANY,
                                        as Trustee


                                    By: /s/ Jill K. Morrison
                                       -------------------------------------
                                        Name: Jill K. Morrison
                                        Title: Administrative Account Manager
<PAGE>   65
                                                                       EXHIBIT A

                               FORM OF CERTIFICATE

REGISTERED

No._________

      [THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE U.S. SECURITIES ACT OF
      1933, AS AMENDED (THE "SECURITIES ACT"), AND ACCORDINGLY, MAY NOT BE
      OFFERED OR SOLD WITHIN THE UNITED STATES OR TO, OR FOR THE ACCOUNT OR
      BENEFIT OF, ANY PERSONS EXCEPT AS SET FORTH IN THE FOLLOWING SENTENCE. BY
      ITS ACQUISITION HEREOF, THE HOLDER (1) REPRESENTS THAT (A) IT IS A
      "QUALIFIED INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A UNDER THE
      SECURITIES ACT), (B) IT IS AN INSTITUTIONAL "ACCREDITED INVESTOR" (AS
      DEFINED IN RULE 501(a)(1), (2), (3) OR (7) OF REGULATION D UNDER THE
      SECURITIES ACT) (AN "INSTITUTIONAL ACCREDITED INVESTOR") OR (C) IT IS NOT
      A U.S. PERSON AND IS ACQUIRING THIS CERTIFICATE IN AN OFFSHORE TRANSACTION
      IN COMPLIANCE WITH REGULATION S UNDER THE SECURITIES ACT; (2) AGREES THAT
      IT WILL NOT WITHIN TWO YEARS AFTER THE LATER OF THE ORIGINAL ISSUANCE OF
      THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS CERTIFICATE WAS HELD BY
      AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY AFFILIATE OF ANY OF SUCH
      PERSONS RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE EXCEPT (A) AMERICA
      WEST AIRLINES, INC., (B) TO A QUALIFIED INSTITUTIONAL BUYER IN COMPLIANCE
      WITH RULE 144A UNDER THE SECURITIES ACT, (C) OUTSIDE THE UNITED STATES IN
      AN OFFSHORE TRANSACTION IN COMPLIANCE WITH RULE 904 UNDER THE SECURITIES
      ACT, (D) PURSUANT TO THE EXEMPTION FROM REGISTRATION PROVIDED BY RULE 144
      UNDER THE SECURITIES ACT (IF AVAILABLE) OR (E) PURSUANT TO AN EFFECTIVE
      REGISTRATION STATEMENT UNDER THE SECURITIES ACT; AND (3) AGREES THAT IF IT
      SHOULD RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE IT WILL DELIVER TO
      EACH PERSON TO WHOM THIS CERTIFICATE IS TRANSFERRED A NOTICE SUBSTANTIALLY
      TO THE EFFECT OF THIS LEGEND. IN CONNECTION WITH ANY TRANSFER OF THIS
      CERTIFICATE WITHIN TWO YEARS AFTER THE LATER OF THE ORIGINAL ISSUANCE OF
      THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS CERTIFICATE WAS HELD BY
      AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY AFFILIATE OF ANY OF SUCH
      PERSONS, THE HOLDER MUST CHECK THE APPROPRIATE BOX SET FORTH ON THE
      REVERSE HEREOF RELATING TO THE MANNER OF SUCH TRANSFER AND SUBMIT THIS
      CERTIFICATE TO THE TRUSTEE. AS USED HEREIN, THE TERMS "OFFSHORE
      TRANSACTION", "UNITED STATES" AND "U.S. PERSON" HAVE THE MEANINGS GIVEN TO
      THEM BY REGULATION S UNDER THE SECURITIES ACT. THE PASS THROUGH TRUST
      AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO REFUSE TO REGISTER
      ANY
<PAGE>   66
                                       A-2


      TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE FOREGOING RESTRICTIONS.]*

      BY ITS ACQUISITION HEREOF, THE HOLDER REPRESENTS THAT (A) NO PLAN ASSETS
      HAVE BEEN USED TO PURCHASE THIS CERTIFICATE OR AN INTEREST HEREIN OR (B)
      THE PURCHASE AND HOLDING OF THIS CERTIFICATE OR AN INTEREST HEREIN IS
      EXEMPT FROM THE PROHIBITED TRANSACTION RESTRICTIONS OF ERISA AND THE CODE
      PURSUANT TO ONE OR MORE PROHIBITED TRANSACTION STATUTORY OR ADMINISTRATIVE
      EXEMPTIONS. THE PASS THROUGH TRUST AGREEMENT CONTAINS A PROVISION
      REQUIRING THE TRUSTEE TO REFUSE TO REGISTER ANY TRANSFER OF THIS
      CERTIFICATE IN VIOLATION OF THE FOREGOING RESTRICTIONS.



      [UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF
      THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE
      TRUSTEE OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT,
      AND ANY CERTIFICATE ISSUED IN EXCHANGE FOR THIS CERTIFICATE IS REGISTERED
      IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN
      AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT HEREON IS MADE TO CEDE &
      CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED
      REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE
      OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED
      OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

      TRANSFERS OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO TRANSFERS IN
      WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A SUCCESSOR THEREOF OR
      SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL
      CERTIFICATE SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE
      RESTRICTIONS SET FORTH IN SECTIONS 3.05 AND 3.06 OF THE PASS THROUGH TRUST
      AGREEMENT REFERRED TO HEREIN.]**


- ----------------

      *     Not to be included on the face of the Regulation S Global
            Certificate.

      **    To be included on the face of each Global Certificate.
<PAGE>   67
                                      A-3


                             [GLOBAL CERTIFICATE]*

           AMERICA WEST AIRLINES PASS THROUGH TRUST, SERIES 1998-1C-O

                7.84% America West Airlines [Initial] [Exchange]
                            Pass Through Certificate,
                                Series 1998-1C-O

                 Final Legal Distribution Date: January 2, 2012

evidencing a fractional undivided interest in a trust, the property of which
includes certain equipment notes each secured by an Aircraft leased to or owned
by America West Airlines, Inc.

            $__________ Fractional Undivided Interest representing
            0.0056481220% of the Trust per $1,000 face amount

            THIS CERTIFIES THAT _______________, for value received, is the
registered owner of a $________ (__________dollars) Fractional Undivided
Interest in the America West Airlines Pass Through Trust, Series 1998-1C-O (the
"Trust") created pursuant to a Pass Through Trust Agreement, dated as of October
6, 1998 (the "Agreement"), between Wilmington Trust Company (the "Trustee") and
America West Airlines, Inc., a corporation incorporated under Delaware law (the
"Company"), a summary of certain of the pertinent provisions of which is set
forth below. To the extent not otherwise defined herein, the capitalized terms
used herein have the meanings assigned to them in the Agreement. This
Certificate is one of the duly authorized Certificates designated as "7.84%
America West Airlines [Initial] [Exchange] Pass Through Certificates, Series
1998-1C-O" (herein called the "Certificates"). This Certificate is issued under
and is subject to the terms, provisions, and conditions of the Agreement. By
virtue of its acceptance hereof the Certificateholder of this Certificate
assents to and agrees to be bound by the provisions of the Agreement and the
Intercreditor Agreement. The property of the Trust includes an interest in
certain Equipment Notes and all rights of the Trust to receive payments under
the Intercreditor Agreement and any Liquidity Facility (the "Trust Property").
Each issue of the Equipment Notes is secured by, among other things, a security
interest in the Aircraft leased to or owned by the Company.


- ------------------

      *           To be included on the face of each Global Certificate.
<PAGE>   68
                                      A-4


            The Certificates represent fractional undivided interests in the
Trust and the Trust Property, and have no rights, benefits or interest in
respect of any assets or property other than the Trust Property.

            Subject to and in accordance with the terms of the Agreement and the
Intercreditor Agreement, from and to the extent of funds then available to the
Trustee, there will be distributed on each January 2 and July 2 (a "Regular
Distribution Date"), commencing on January 2, 1999, to the Person in whose name
this Certificate is registered at the close of business on the 15th day
preceding the Regular Distribution Date, an amount in respect of the Scheduled
Payments due on such Regular Distribution Date on the Equipment Notes, the
receipt of which has been confirmed by the Trustee, equal to the product of the
percentage interest in the Trust evidenced by this Certificate and an amount
equal to the sum of such Scheduled Payments. Subject to and in accordance with
the terms of the Agreement and the Intercreditor Agreement, in the event that
Special Payments on the Equipment Notes are received by the Trustee, from funds
then available to the Trustee, there shall be distributed on the applicable
Special Distribution Date, to the Person in whose name this Certificate is
registered at the close of business on the 15th day preceding the Special
Distribution Date, an amount in respect of such Special Payments on the
Equipment Notes, the receipt of which has been confirmed by the Trustee, equal
to the product of the percentage interest in the Trust evidenced by this
Certificate and an amount equal to the sum of such Special Payments so received.
If a Regular Distribution Date or Special Distribution Date is not a Business
Day, distribution shall be made on the immediately following Business Day with
the same force and effect as if made on such Regular Distribution Date or
Special Distribution Date and no interest shall accrue during the intervening
period. The Trustee shall mail notice of each Special Payment and the Special
Distribution Date therefor to the Certificateholder of this Certificate.

            The Certificates do not represent a direct obligation of, or an
obligation guaranteed by, or an interest in, the Company or the Trustee or any
of their affiliates. The Certificates are limited in right or payment, all as
more specifically set forth on the face hereof and in the Agreement. All
payments or distributions made to Certificateholders under the Agreement shall
be made only from the Trust Property and only to the extent that the Trustee
shall have sufficient income or proceeds from the Trust Property to make such
payments in accordance with the terms of the Agreement. Each Certificate-holder
of this Certificate, by its acceptance hereof, agrees that it will look solely
to the income and proceeds from the Trust Property to the extent available for
distribution to such Certificateholder as provided in the Agreement. This
Certificate does not purport to summarize the Agreement and reference is made to
the Agreement for information with respect to the interests, rights, benefits,
obligations, proceeds, and duties evidenced hereby. A copy of the Agreement may
be examined during normal business hours at the principal office of the Trustee,
and at such other places, if any, designated by the Trustee, by any
Certificateholder upon request.

            The Agreement permits, with certain exceptions therein provided, the
amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Certificateholders under the Agreement at any time
by the Company and the Trustee with the consent of the Certificateholders
holding Certificates evidencing Fractional Undivided Interests aggregating not
less than a majority in interest in the Trust. Any such consent by the
Certificateholder of this Certificate shall be conclusive and binding on such
Certificateholder and
<PAGE>   69
                                      A-5


upon all future Certificateholders of this Certificate and of any Certificate
issued upon the transfer hereof or in exchange hereof or in lieu hereof whether
or not notation of such consent is made upon this Certificate. The Agreement
also permits the amendment thereof, in certain limited circumstances, without
the consent of the Certificateholders of any of the Certificates.

            As provided in the Agreement and subject to certain limitations
therein set forth, the transfer of this Certificate is registrable in the
Register upon surrender of this Certificate for registration of transfer at the
offices or agencies maintained by the Trustee in its capacity as Registrar, or
by any successor Registrar, in the Borough of Manhattan, the City of New York,
duly endorsed or accompanied by a written instrument of transfer in form
satisfactory to the Trustee and the Registrar duly executed by the
Certificateholder hereof or such Certificateholder's attorney duly authorized in
writing, and thereupon one or more new Certificates of authorized denominations
evidencing the same aggregate Fractional Undivided Interest in the Trust will be
issued to the designated transferee or transferees.

            [The Holder of this Certificate is entitled to the benefits of the
Exchange and Registration Rights Agreement, dated as of October 6, 1998, among
the Company, the Trustee and the Initial Purchasers named therein (the
"Registration Rights Agreement"). In the event that no Registration Event has
occurred on or prior to the 210th day after the date of the issuance of the
Certificates, the interest rate per annum payable in respect of the Equipment
Notes and the Deposits shall be increased by 0.50%, from and including the 210th
day after the Issuance Date to but excluding the earlier of (i) the date on
which a Registration Event occurs and (ii) the date on which there cease to be
any Registrable Certificates (as defined in the Registration Rights Agreement).
In the event that the Shelf Registration Statement ceases to be effective at any
time during the period specified by Section 2(b)(B) of the Registration Rights
Agreement for more than 60 days, whether or not consecutive, during any 12-month
period, the interest rate per annum payable in respect of the Equipment Notes
and the Deposits shall be increased by 0.50% from the 61st day of the applicable
12-month period such Shelf Registration Statement ceases to be effective until
such time as the Shelf Registration Statement again becomes effective ( or, if
earlier, the end of the period specified by Section 2(b)(B) of the Registration
Rights Agreement).]*

            Except as otherwise provided in the Agreement and notwithstanding
the above, the final distribution on this Certificate will be made after notice
mailed by the Trustee of the pendency of such distribution and only upon
presentation and surrender of this Certificate at the office or agency of the
Trustee specified in such notice.

            Under certain circumstances set forth in Section 11.01 of the
Agreement, all of the Trustee's right, title and interest to the Trust Property
may be assigned, transferred and delivered to the Related Trustee of the Related
Trust pursuant to the Assignment and Assumption Agreement. Upon the
effectiveness of such Assignment and Assumption Agreement (the


- --------------------

      *     To be included only on each Initial Certificate.
<PAGE>   70
                                      A-6


"Transfer"), the Trust shall be terminated, the Certificateholders shall receive
beneficial interests in the Related Trust in exchange for their interests in the
Trust equal to their respective beneficial interests in the Trust, the
Certificates representing Fractional Undivided Interests in the Trust shall be
deemed for all purposes of the Agreement and the Related Pass Through Trust
Agreement to be certificates representing the same fractional undivided
interests in the Related Trust and its trust property. Each Certificateholder,
by its acceptance of this Certificate or a beneficial interest herein, agrees to
be bound by the Assignment and Assumption Agreement and subject to the terms of
the Related Pass Through Trust Agreement as a certificateholder thereunder. From
and after the Transfer, unless and to the extent the context otherwise requires,
references herein to the Trust, the Agreement and the Trustee shall constitute
references to the Related Trust, the Related Pass Through Trust Agreement and
trustee of the Related Trust, respectively.

            The Certificates are issuable only as registered Certificates
without coupons in minimum denominations of [$100,000]* [$1,000]** Fractional
Undivided Interest and integral multiples of $1,000 in excess thereof except
that one Certificate may be in a different denomination. As provided in the
Agreement and subject to certain limitations therein set forth, the Certificates
are exchangeable for new Certificates of authorized denominations evidencing the
same aggregate Fractional Undivided Interest in the Trust, as requested by the
Certificateholder surrendering the same.

            No service charge will be made for any such registration of transfer
or exchange, but the Trustee shall require payment by the Holder of a sum
sufficient to cover any tax or governmental charge payable in connection
therewith.

            Each Certificateholder or Investor that is not a United States
person within the meaning of Section 7701(a)(30) of the Internal Revenue Code,
as amended, by its acceptance of a Certificate or a beneficial interest therein,
agrees to indemnify and hold harmless the Trust and the Trustee from and against
any improper failure to withhold taxes from amounts payable to it or for its
benefit. Each Certificateholder and Investor, by its acceptance of this
Certificate or a beneficial interest herein, agrees to treat the Trust as a
grantor trust for all U.S. federal, state and local income tax purposes.

            The Trustee, the Registrar, and any agent of the Trustee or the
Registrar may treat the person in whose name this Certificate is registered as
the owner hereof for all purposes, and neither the Trustee, the Registrar, nor
any such agent shall be affected by any notice to the contrary.

            The obligations and responsibilities created by the Agreement and
the Trust created thereby shall terminate upon the distribution to
Certificateholders of all amounts required


- ---------------


      *     To be included only on each Initial Certificate.

      **    To be included only on each Exchange Certificate.
<PAGE>   71
                                      A-7


to be distributed to them pursuant to the Agreement and the disposition of all
property held as part of the Trust Property.

            UNTIL THE TRANSFER, THE AGREEMENT AND THIS CERTIFICATE SHALL BE
GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF DELAWARE
AND THE OBLIGATIONS, RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER SHALL BE
DETERMINED IN ACCORDANCE WITH SUCH LAWS. FROM AND AFTER THE TRANSFER, THE
AGREEMENT AND THIS CERTIFICATE SHALL BE GOVERNED AND CONSTRUED IN ACCORDANCE
WITH THE LAWS OF THE STATE OF NEW YORK AND THE OBLIGATIONS, RIGHTS AND REMEDIES
OF THE PARTIES HEREUNDER SHALL BE DETERMINED IN ACCORDANCE WITH SUCH LAWS.

            Unless the certificate of authentication hereon has been executed by
the Trustee, by manual signature, this Certificate shall not be entitled to any
benefit under the Agreement or be valid for any purpose.
<PAGE>   72
                                      A-8


            IN WITNESS WHEREOF, the Trustee has caused this Certificate to be
duly executed.


Dated: October 6, 1998

                                    AMERICA WEST AIRLINES PASS THROUGH TRUST,
                                      SERIES 1998-1C-O



                                    By:  WILMINGTON TRUST COMPANY, not in its
                                         individual capacity
                                         but solely as Trustee


                                    By: ____________________________________
                                        Name:
                                        Title:

[Attest:


_____________________
Authorized Signature]
<PAGE>   73
                                      A-9


              [FORM OF THE TRUSTEE'S CERTIFICATE OF AUTHENTICATION]

               This is one of the Certificates referred to in the
                           within-mentioned Agreement.



                                    WILMINGTON TRUST COMPANY,
                                    not in its individual capacity but solely
                                    as Trustee


                                    By:__________________________________
                                       Authorized Officer
<PAGE>   74
                                      A-10


                             FORM OF TRANSFER NOTICE

            FOR VALUE RECEIVED the undersigned registered holder hereby
sell(s), assign(s) and transfer(s) unto

Insert Taxpayer Identification No.

______________________

______________________


please print or typewrite name and address including zip code of assignee

______________________

the within Certificate and all rights thereunder, hereby irrevocably
constituting and appointing

______________________

attorney to transfer said Certificate on the books of the Trustee with full
power of substitution in the premises.

                     [THE FOLLOWING PROVISION TO BE INCLUDED
                               ON ALL CERTIFICATES
                         EXCEPT REGULATION S GLOBAL AND
                      REGULATION S DEFINITIVE CERTIFICATES]

            In connection with any transfer of this Certificate occurring prior
to the date that is the earlier of the date of an effective Registration
Statement or the date two years after the later of the original issuance of this
Certificate or the last date on which this Certificate was held by America West
Airlines, Inc., the Trustee or any affiliate of such Persons, the undersigned
confirms that without utilizing any general solicitation or general advertising
that:

                                   [Check One]

[ ] (a) this Certificate is being transferred in compliance with the exemption
from registration under the Securities Act of 1933, as amended, provided by Rule
144A thereunder.

                                       or

[ ] (b) this Certificate is being transferred other than in accordance with (a)
above and documents are being furnished that comply with the conditions of
transfer set forth in this Certificate and the Agreement.

If neither of the foregoing boxes is checked, the Trustee or other Registrar
shall not be obligated to register this Certificate in the name of any Person
other than the Holder hereof unless and until the conditions to any such
transfer of registration set forth herein and in Section 3.06 of the Agreement
shall have been satisfied.
<PAGE>   75
                                      A-11


Date:__________________             [Name of Transferor]

                                    NOTE: The signature must correspond with the
                                    name as written upon the face of the
                                    within-mentioned instrument in every
                                    particular, without alteration or any change
                                    whatsoever.

Signature Guarantee: ______________________

TO BE COMPLETED BY PURCHASER IF (a) ABOVE IS CHECKED.

            The undersigned represents and warrants that it is purchasing this
Certificate for its own account or an account with respect to which it exercises
sole investment discretion and that it and any such account is a "qualified
institutional buyer" within the meaning of Rule 144A under the Securities Act of
1933, as amended, and is aware that the sale to it is being made in reliance on
Rule 144A and acknowledges that it has received such information regarding the
Company as the undersigned has requested pursuant to Rule 144A or has determined
not to request such information and that it is aware that the transferor is
relying upon the undersigned's foregoing representations in order to claim the
exemption from registration provided by Rule 144A.

Dated:__________________            _____________________________
                                    NOTE:    To be executed by an executive
                                    officer.
<PAGE>   76
                                                                       EXHIBIT B

             FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION WITH
               TRANSFERS OF CERTIFICATES PURSUANT TO REGULATION S

                                                      [date]

Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE  19890-0001

Attention:  Corporate Trust Trustee Administration

      Re:   America West Airlines Pass Through Trust (the "Trust"),
            Series 1998-1C-O, America West Airlines Pass Through
            Certificates, Series 1998-1C-O (the "Certificates")

Sirs:

            In connection with our proposed sale of $_____ Fractional Undivided
Interest of the Certificates, we confirm that such sale has been effected
pursuant to and in accordance with Regulation S under the Securities Act of
1933, as amended, and, accordingly, we represent that:

            (1) the offer of the Certificates was not made to a person in the
      United States or to or for the account or benefit of a U.S. person;

            (2) either (a) at the time the buy order was originated, the
      transferee was outside the United States or we and any person acting on
      our behalf reasonably believed that the transferee was outside the United
      States or (b) the transaction was executed in, on or through the
      facilities of a designated off-shore securities market and neither we nor
      any person acting on our behalf knows that the transaction has been
      pre-arranged with a buyer in the United States;

            (3) no directed selling efforts have been made in the United States
      in contravention of the requirements of Rule 903(a) or Rule 904(a) of
      Regulation S, as applicable; and

            (4) the transaction is not part of a plan or scheme to evade the
      registration requirements of the Securities Act.

            In addition, if the sale is made during a restricted period and the
provisions of Rule 903(b)(2) or Rule 904(b)(1) of Regulation S are applicable
thereto, we confirm that such sale has been made in accordance with the
applicable provisions of Rule 903(b)(2) or Rule 904(b)(1), as the case may be.

            You and America West Airlines, Inc. are entitled to rely upon this
letter and are irrevocably authorized to produce this letter or a copy hereof to
any interested party in any
<PAGE>   77
                                      B-2


administrative or legal proceedings or official
inquiry with respect to the matters covered hereby. Terms used in this
certificate have the meanings set forth in Regulation S.

                                    Very truly yours,

                                    [Name of Transferor]
<PAGE>   78
                                                                       EXHIBIT C

                FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION
                        WITH TRANSFERS OF CERTIFICATES TO
                   NON-QIB INSTITUTIONAL ACCREDITED INVESTORS

                                                      [date]

Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE  19890-0001
Attention:  Corporate Trust Trustee Administration

America West Airlines, Inc.
4000 East Sky Harbor Boulevard
Phoenix, Arizona  85043


                              AMERICA WEST AIRLINES
               PASS THROUGH TRUST, SERIES 1998-1C-O (the "Trust")
                   Pass Through Certificates, Series 1998-1C-O
                              (the "Certificates")
                               _________________


Ladies and Gentlemen:

      In connection with our proposed purchase of U.S. $[_____________]
Fractional Undivided Interest of Certificates, we confirm that:

      1. We understand that any subsequent transfer of the Certificates is
subject to certain restrictions and conditions set forth in the Pass Through
Trust Agreement, dated as of October 6, 1998, between America West Airlines,
Inc. (the "Company") and Wilmington Trust Company (the "Trustee") relating to
the Certificates, and we agree to be bound by, and not to resell, pledge or
otherwise transfer the Certificates except in compliance with, such restrictions
and conditions and the Securities Act of 1933, as amended (the "Securities
Act").

      2. We are purchasing Certificates having an aggregate principal amount of
not less than $100,000 and each account (if any) for which we are purchasing
Certificates is purchasing Certificates having an aggregate principal amount of
not less than $100,000.

      3. We understand that the Certificates have not been registered under the
Securities Act, that the Certificates are being sold to us in a transaction that
is exempt from the registration requirements of the Securities Act and that the
Certificates may not be offered or resold except as permitted in the following
sentence. We agree, on our own behalf and on behalf of any accounts for which we
are acting as hereinafter stated, that, if we should sell any Certificates
within two years after the later of the original issuance of such Certificate
and the last date on which such Certificate is owned by the Company, the Trustee
or any affiliate of any of such persons, we will
<PAGE>   79
                                      C-2


do so only (A) to the Company, (B) in accordance with Rule 144A under the
Securities Act to a "qualified institutional buyer" (as defined therein), (C)
outside the United States in accordance with Rule 904 of Regulation S under the
Securities Act, (D) pursuant to the exemption from registration provided by Rule
144 under the Securities Act or (E) pursuant to an effective registration
statement under the Securities Act, and we further agree to provide to any
person purchasing any of the Certificates from us a notice advising such
purchaser that resales of the Certificates are restricted as stated herein.

      4. We understand that, on any proposed resale of any Certificates, we will
be required to furnish to the Company and the Trustee such certifications, legal
opinions and other information as the Company and the Trustee may reasonably
require to confirm that the proposed sale complies with the foregoing
restrictions. We further understand that the Certificates purchased by us will
bear a legend to the foregoing effect.

      5. We are an institutional "accredited investor" (as defined in Rule
501(a)(1), (2), (3) or (7) of Regulation D under the Securities Act) and have
such knowledge and experience in financial and business matters as to be capable
of evaluating the merits and risks of our investment in the Certificates, and we
and any accounts for which we are acting are each able to bear the economic risk
of our or their investments.

      6. We are acquiring the Certificates purchased by us for our own account
or for one or more accounts (each of which is an institutional "accredited
investor") as to each of which we exercise sole investment discretion and not
with a view to any distribution of the Certificates, subject, nevertheless to
the understanding that the disposition of our property shall at all times be and
remain within our control.

            You are entitled to rely upon this letter and are irrevocably
authorized to produce this letter or a copy thereof to any interested party in
any administrative or legal proceedings or official inquiry with respect to the
matters covered hereby.

                                    Very truly yours,



                                    By: _____________________________________
                                        Name:
                                        Title:
<PAGE>   80
                                                                       EXHIBIT D

            FORM OF ASSIGNMENT AND ASSUMPTION AGREEMENT America West
                   Airlines Pass Through Trust, Series 1998-1C


            ASSIGNMENT AND ASSUMPTION AGREEMENT, dated ____________, 199_ (the
"Agreement"), between Wilmington Trust Company, a Delaware banking corporation
("WTC"), not in its individual capacity except as expressly provided herein, but
solely as trustee under the Pass Through Trust Agreement dated as of October 6,
1998 (as amended, modified or otherwise supplemented from time to time, the
"Pass Through Trust Agreement") in respect of the America West Airlines Pass
Through Trust, Series 1998-1C-O (the "Assignor"), and Wilmington Trust Company,
a Delaware banking corporation, not in its individual capacity except as
expressly provided herein, but solely as trustee under the Pass Through Trust
Agreement dated as of October 6, 1998 (the "New Pass Through Trust Agreement")
in respect of the America West Airlines Pass Through Trust, Series 1998-1C-S
(the "Assignee").

                              W I T N E S S E T H:

            WHEREAS, the parties hereto desire to effect on the date hereof (the
"Transfer Date") (a) the transfer by the Assignor to the Assignee of all of the
right, title and interest of the Assignor in, under and with respect to, among
other things, the Trust Property and each of the documents listed in Schedule I
hereto (the "Scheduled Documents") and (b) the assumption by the Assignee of the
obligations of the Assignor (i) under the Scheduled Documents and (ii) in
respect of the Certificates issued under the Pass Through Trust Agreement; and

            WHEREAS, the Scheduled Documents permit such transfer upon
satisfaction of certain conditions heretofore or concurrently herewith being
complied with;

            NOW, THEREFORE, in consideration of the premises and of the mutual
covenants and agreements herein contained, the parties hereto do hereby agree as
follows (capitalized terms used herein without definition having the meaning
ascribed thereto in the Pass Through Trust Agreement):

            1. Assignment. The Assignor does hereby sell, assign, convey,
transfer and set over unto the Assignee as of the Transfer Date all of its
present and future right, title and interest in, under and with respect to the
Trust Property and the Scheduled Documents and each other contract, agreement,
document or instrument relating to the Trust Property or the Scheduled Documents
(such other contracts, agreements, documents or instruments, together with the
Scheduled Documents, to be referred to as the "Assigned Documents"), and any
proceeds therefrom, together with all documents and instruments evidencing any
of such right, title and interest.

            2. Assumption. The Assignee hereby assumes for the benefit of the
Assignor and each of the parties listed in Schedule II hereto (collectively, the
"Beneficiaries") all of the duties and obligations of the Assignor, whenever
accrued, pursuant to the Assigned Documents and hereby confirms that it shall be
deemed a party to each of the Assigned Documents to which the Assignor is a
party and shall be bound by all the terms thereof (including the agreements and
obligations of the Assignor set forth therein) as if therein named as the
Assignor. Further, the Assignee hereby assumes for the benefit of the Assignor
and the Beneficiaries all of the duties
<PAGE>   81
                                      D-2


and obligations of the Assignor under the Outstanding Certificates and hereby
confirms that the Certificates representing Fractional Undivided Interests under
the Pass Through Trust Agreement shall be deemed for all purposes of the Pass
Through Trust Agreement and the New Pass Through Trust Agreement to be
certificates representing the same fractional undivided interests under the New
Pass Through Trust Agreement equal to their respective beneficial interests in
the trust created under the Pass Through Trust Agreement.

            3. Effectiveness. This Agreement shall be effective upon the
execution and delivery hereof by the parties hereto, and each Certificateholder,
by its acceptance of its Certificate or a beneficial interest therein, agrees to
be bound by the terms of this Agreement.

            4. Payments. The Assignor hereby covenants and agrees to pay over to
the Assignee, if and when received following the Transfer Date, any amounts
(including any sums payable as interest in respect thereof) paid to or for the
benefit of the Assignor that, under Section 1 hereof, belong to the Assignee.

            5. Further Assurances. The Assignor shall, at any time and from time
to time, upon the request of the Assignee, promptly and duly execute and deliver
any and all such further instruments and documents and take such further action
as the Assignee may reasonably request to obtain the full benefits of this
Agreement and of the right and powers herein granted. The Assignor agrees to
deliver the Global Certificates, and all Trust Property, if any, then in the
physical possession of the Assignor, to the Assignee.

            6. Representations and Warranties. (a) The Assignee represents and
warrants to the Assignor and each of the Beneficiaries that:

            (i) it has all requisite power and authority and legal right to
      enter into and carry out the transactions contemplated hereby and to carry
      out and perform the obligations of the "Pass Through Trustee" under the
      Assigned Documents;

            (ii) on and as of the date hereof, the representations and
      warranties of the Assignee set forth in Section 7.15 of the New Pass
      Through Trust Agreement are true and correct.

            (b) The Assignor represents and warrants to the Assignee that:

            (i) it is duly incorporated, validly existing and in good standing
      under the laws of the State of Delaware and has the full trust power,
      authority and legal right under the laws of the State of Delaware and the
      United States pertaining to its trust and fiduciary powers to execute and
      deliver this Agreement;

            (ii) the execution and delivery by it of this Agreement and the
      performance by it of its obligations hereunder have been duly authorized
      by it and will not violate its articles of association or by-laws or the
      provisions of any indenture, mortgage, contract or other agreement to
      which it is a party or by which it is bound; and

            (iii) this Agreement constitutes the legal, valid and binding
      obligations of it enforceable against it in accordance with its terms,
      except as the same may be limited by applicable bankruptcy, insolvency,
      reorganization, moratorium or similar laws affecting
<PAGE>   82
                                      D-3


      the rights of creditors generally and by general principles of equity,
      whether considered in a proceeding at law or in equity.

            7. GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED
IN ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK INCLUDING MATTERS OF
CONSTRUCTION, VALIDITY AND PERFORMANCE, WITHOUT GIVING EFFECT TO PRINCIPLES OF
CONFLICTS OF LAWS.

            8. Counterparts. This Agreement may be executed in any number of
counterparts, all of which together shall constitute a single instrument. It
shall not be necessary that any counterpart be signed by both parties so long as
each party shall sign at least one counterpart.

            9. Third Party Beneficiaries. The Assignee hereby agrees, for the
benefit of the Beneficiaries, that its representations, warranties and covenants
contained herein are also intended to be for the benefit of each Beneficiary,
and each Beneficiary shall be deemed to be an express third party beneficiary
with respect thereto, entitled to enforce directly and in its own name any
rights or claims it may have against such party as such beneficiary.

            IN WITNESS WHEREOF, the parties hereto, through their respective
officers thereunto duly authorized, have duly executed this Assignment as of the
day and year first above written.

                                    ASSIGNOR:

                                    WILMINGTON TRUST COMPANY, not in its
                                    individual capacity except as expressly
                                    provided herein, but solely as trustee under
                                    the Pass Through Trust Agreement in respect
                                    of the America West Airlines Pass Through
                                    Trust 1998-1C-O


                                    By: _______________________________________
                                        Title:

                                    ASSIGNEE:

                                    WILMINGTON TRUST COMPANY, not in its
                                    individual capacity except as expressly
                                    provided herein, but solely as trustee under
                                    the Pass Through Trust Agreement in respect
                                    of the America West Airlines Pass Through
                                    Trust 1998-1C-S


                                    By: _______________________________________
                                        Title:
<PAGE>   83
                                                                      Schedule I

                         Schedule of Assigned Documents

(1)   Intercreditor Agreement dated as of October 6, 1998 among the Trustee, the
      Other Trustees, the Liquidity Provider, the liquidity provider, if any,
      relating to the Certificates issued under (and as defined in) each of the
      Other Pass Through Trust Agreements and the Subordination Agent.

(2)   Registration Rights Agreement dated as of October 6, 1998 among the
      Initial Purchasers, the Trustee, the Other Trustees, and the Company.

(3)   Escrow and Paying Agent Agreement (Class A) dated as of October 6, 1998
      among the Escrow Agent, the Initial Purchasers, the Trustee and the Paying
      Agent.

(4)   Note Purchase Agreement dated as of October 6, 1998 among the Company, the
      Trustee, the Other Trustees, the Depositary, the Escrow Agent, the Paying
      Agent and the Subordination Agent.

(5)   Deposit Agreement (Class A) dated as of October 6, 1998 between the
      Escrow Agent and the Depositary.

(6)   Each of the Operative Agreements (as defined in the Participation
      Agreement for each Aircraft) in effect as of the Transfer Date.
<PAGE>   84
                                                                     Schedule II

                            Schedule of Beneficiaries

Wilmington Trust Company, not in its individual capacity but solely as
Subordination Agent.

Wilmington Trust Company, not in its individual capacity but solely as Paying
Agent

ABN AMRO Bank, N.V., acting through its Chicago branch, as Liquidity Provider

America West Airlines, Inc.

Morgan Stanley & Co. Incorporated, as Initial Purchaser

Donaldson, Lufkin & Jenrette Securities Corporation, as Initial Purchaser

Merrill Lynch, Pierce, Fenner & Smith Incorporated, as Initial Purchaser

Salomon Smith Barney Inc., as Initial Purchaser

Wilmington Trust Company, as Escrow Agent

Each of the other parties to the Assigned Documents
<PAGE>   85
                                                                       EXHIBIT E

            FORM OF NOTICE TO DESIGNATE NOMINEE AS WITHHOLDING AGENT
          (Treas. Reg. Section 1.1445-8(f); 17 C.F.R. 240.10b-17(b)(1))

                                                                          [DATE]

National Association of
Securities Dealers, Inc.
Market Operations
80 Merritt Blvd.
Trumbull, CT  06611

      Re:   America West Airlines Pass Through Trust, Series 1998-1C-O
            Pass Through Certificates, Series 1998-1C-O

            With respect to distributions to be made on [INSERT DISTRIBUTION
DATE] to holders of the above-referenced Pass Through Certificates in the amount
of $ ____ per $1,000 principal amount of Certificate, we hereby designate the
appropriate nominees to withhold from amounts distributable to any non-U.S.
Person such amounts as required by Section 1446 of the Internal Revenue Code of
1986, as amended. The term "non-U.S. Person" means any person or entity that,
for U.S. federal income tax purposes, is not a "U.S. Person." "U.S. Person" for
this purpose means a citizen or resident of the United States, a corporation,
partnership or other entity created or organized under the laws of the United
States or any political subdivision thereof, or an estate or trust, the income
of which is subject to U.S. federal income taxation regardless of its source.
The date of record for determining holders of Certificates entitled to receive
the distribution on [INSERT DISTRIBUTION DATE] is [INSERT RELATED RECORD DATE].

                                Very truly yours,




<PAGE>   1
                                                                     EXHIBIT 4.9










                          PASS THROUGH TRUST AGREEMENT

                           Dated as of October 6, 1998

                                     between

                           AMERICA WEST AIRLINES, INC.

                                       And

                            WILMINGTON TRUST COMPANY,

                                   as Trustee

           America West Airlines Pass Through Trust, Series 1998-1C-S

            7.84% Initial Pass Through Certificates, Series 1998-1C-S
           7.84% Exchange Pass Through Certificates, Series 1998-1C-S





<PAGE>   2
Reconciliation and tie between America West Airlines Pass Through Trust
Agreement, Series 1998-1C-S dated as of October 6, 1998, and the Trust Indenture
Act of 1939. This reconciliation does not constitute part of the Pass Through
Trust Agreement.

          Trust Indenture Act                     Pass Through Trust
            of 1939 Section                        Agreement Section
            ---------------                        -----------------
            310(a)(1)                                  7.08
               (a)(2)                                  7.08
            312(a)                                     3.05; 8.01; 8.02
            313(a)                                     7.06; 8.03
            314(a)                                     8.04(a),(c) & (d)
            (a)(4)                                     8.04(e)
            (c)(1)                                     1.02
            (c)(2)                                     1.02
            (d)(1)                                     7.13; 11.01
            (d)(2)                                     7.13; 11.01
            (d)(3)                                     2.01
            (e)                                        1.02
            315(b)                                     7.02
            316(a)(last sentence)                      1.04(c)
               (a)(1)(A)                               6.04
               (a)(1)(B)                               6.05
               (b)                                     6.06
               (c)                                     1.04(e)
            317(a)(1)                                  6.03
               (b)                                     7.13
            318(a)                                    12.06
<PAGE>   3
                                TABLE OF CONTENTS

SECTION                                                                     PAGE
- -------                                                                     ----

ARTICLE I  DEFINITIONS.........................................................2
      Section 1.01.     Definitions............................................2
      Section 1.02.     Compliance Certificates and Opinions..................13
      Section 1.03.     Form of Documents Delivered to Trustee................14
      Section 1.04.     Directions of Certificateholders......................14

ARTICLE II  ACQUISITION OF TRUST PROPERTY.....................................15
      Section 2.01.     Acquisition of Trust Property.........................15
      Section 2.02.     Acceptance by Trustee.................................16
      Section 2.03.     Limitation of Powers..................................16

ARTICLE III  THE CERTIFICATES.................................................16
      Section 3.01.     Title, Form, Denomination and Execution of
                        Certificates..........................................16
      Section 3.02.     Restrictive Legends...................................19
      Section 3.03.     Authentication of Certificates........................20
      Section 3.04.     Transfer and Exchange.................................20
      Section 3.05.     Book-Entry Provisions for Restricted Global
                        Certificates and Regulation S Global
                        Certificates..........................................21
      Section 3.06.     Special Transfer Provisions...........................23
      Section 3.07.     Mutilated, Destroyed, Lost or Stolen
                        Certificates..........................................25
      Section 3.08.     Persons Deemed Owners.................................26
      Section 3.09.     Cancellation..........................................26
      Section 3.10.     Temporary Certificates................................26
      Section 3.11.     Limitation of Liability for Payments..................27
      Section 3.12      ERISA Restrictive Legend..............................27

ARTICLE IV  DISTRIBUTIONS; STATEMENTS TO CERTIFICATEHOLDERS...................28
      Section 4.01.     Certificate Account and Special Payments Account......28
      Section 4.02.     Distributions from Certificate Account and
                        Special Payments Account..............................28
      Section 4.03.     Statements to Certificateholders......................29
      Section 4.04.     Investment of Special Payment Moneys..................31

ARTICLE V  THE COMPANY........................................................31
      Section 5.01.     Maintenance of Corporate Existence....................31
      Section 5.02.     Consolidation, Merger, Etc............................31

ARTICLE VI  DEFAULT...........................................................32
      Section 6.01.     Events of Default.....................................32
      Section 6.02.     Incidents of Sale of Equipment Notes..................34
      Section 6.03.     Judicial Proceedings Instituted by Trustee;
                        Trustee May Bring Suit................................34
      Section 6.04.     Control by Certificateholders.........................35
<PAGE>   4
SECTION                                                                     PAGE
- -------                                                                     ----

      Section 6.05.     Waiver of Past Defaults...............................35
      Section 6.06.     Right of Certificateholders to Receive Payments
                        Not to Be Impaired....................................36
      Section 6.07.     Certificateholders May Not Bring Suit Except
                        Under Certain Conditions..............................36
      Section 6.08.     Remedies Cumulative...................................36

ARTICLE VII  THE TRUSTEE......................................................37
      Section 7.01.     Certain Duties and Responsibilities...................37
      Section 7.02.     Notice of Defaults....................................37
      Section 7.03.     Certain Rights of Trustee.............................37
      Section 7.04.     Not Responsible for Recitals or Issuance of
                        Certificates..........................................39
      Section 7.05.     May Hold Certificates.................................39
      Section 7.06.     Money Held in Trust...................................39
      Section 7.07.     Compensation and Reimbursement........................39
      Section 7.08.     Corporate Trustee Required; Eligibility...............40
      Section 7.09.     Resignation and Removal; Appointment of
                        Successor.............................................41
      Section 7.10.     Acceptance of Appointment by Successor................42
      Section 7.11.     Merger, Conversion, Consolidation or Succession
                        to Business...........................................42
      Section 7.12.     Maintenance of Agencies...............................43
      Section 7.13.     Money for Certificate Payments to Be Held in
                        Trust.................................................44
      Section 7.14.     Registration of Equipment Notes in Name of
                        Subordination Agent...................................44
      Section 7.15.     Representations and Warranties of Trustee.............44
      Section 7.16.     Withholding Taxes, Information Reporting..............45
      Section 7.17.     Trustee's Liens.......................................46
      Section 7.18.     Preferential Collection of Claims.....................46

ARTICLE VIII  CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE................46
      Section 8.01.     The Company to Furnish Trustee with Names and
                        Addresses of Certificateholders.......................46
      Section 8.02.     Preservation of Information; Communications to
                        Certificateholders....................................46
      Section 8.03.     Reports by Trustee....................................47
      Section 8.04.     Reports by the Company................................47

ARTICLE IX  SUPPLEMENTAL AGREEMENTS...........................................48
      Section 9.01.     Supplemental Agreements Without Consent of
                        Certificateholders....................................48
      Section 9.02.     Supplemental Agreements with Consent of
                        Certificateholders....................................49
      Section 9.03.     Documents Affecting Immunity or Indemnity.............50
      Section 9.04.     Execution of Supplemental Agreements..................50
      Section 9.05.     Effect of Supplemental Agreements.....................50
      Section 9.06.     Conformity with Trust Indenture Act...................50
      Section 9.07.     Reference in Certificates to Supplemental
                        Agreements............................................51


                                       ii
<PAGE>   5
SECTION                                                                     PAGE
- -------                                                                     ----

ARTICLE X  AMENDMENTS TO INDENTURES AND FINANCING DOCUMENTS...................51
      Section 10.01.    Amendments and Supplements to Indentures and
                        Financing Documents...................................51

ARTICLE XI  TERMINATION OF TRUST..............................................52
      Section 11.01.    Termination of the Trust..............................52

ARTICLE XII  MISCELLANEOUS PROVISIONS.........................................52
      Section 12.01.    Limitation on Rights of Certificateholders............52
      Section 12.02.    Certificates Nonassessable and Fully Paid.............53
      Section 12.03.    Notices...............................................53
      Section 12.04.    Governing Law.........................................54
      Section 12.05.    Severability of Provisions............................54
      Section 12.06.    Trust Indenture Act Controls..........................54
      Section 12.07.    Effect of Headings and Table of Contents..............54
      Section 12.08.    Successors and Assigns................................54
      Section 12.09.    Benefits of Agreement.................................55
      Section 12.10.    Legal Holidays........................................55
      Section 12.11.    Counterparts..........................................55
      Section 12.12.    Intention of Parties..................................55


Exhibit A - Form of Certificate to Request Removal of Restricted Legend
Exhibit B - Form of Certificate to be Delivered by an Institutional Accredited 
            Investor

                                      iii
<PAGE>   6
                          PASS THROUGH TRUST AGREEMENT


            This PASS THROUGH TRUST AGREEMENT, dated as of October 6, 1998, (the
"Agreement") between AMERICA WEST AIRLINES, INC., a Delaware corporation, and
WILMINGTON TRUST COMPANY, as Trustee, is made with respect to the formation of
America West Airlines Pass Through Trust, Series 1998-1C-S and the 7.84% America
West Airlines Pass Through Trust, Series 1998-1C-S Pass Through Certificates
representing fractional undivided interests in the Trust.

                                   WITNESSETH:

            WHEREAS, the Company has obtained commitments from AVSA for the
delivery of certain Aircraft;

            WHEREAS, as of the Transfer Date, the Company will have financed (or
refinanced) the acquisition all or a portion of the Aircraft either (i) through
separate leveraged lease transactions in which the Company leases such aircraft
(collectively, the "Leased Aircraft") or (ii) through separate secured loan
transactions in which the Company owns such Aircraft (collectively, the "Owned
Aircraft");

            WHEREAS, as of the Transfer Date, in the case of each Leased
Aircraft, each Owner Trustee, acting on behalf of the corresponding Owner
Participant, will have issued pursuant to an Indenture, on a non-recourse basis,
three (or, subject to satisfaction of certain preconditions contained in the
Note Purchase Agreement, four) series of Equipment Notes in order to finance a
portion of its purchase price of such Leased Aircraft;

            WHEREAS, as of the Transfer Date, in the case of each Owned
Aircraft, the Company, will have issued pursuant to an Indenture, on a recourse
basis, three (or, subject to satisfaction of certain preconditions contained in
the Note Purchase Agreement, four) series of Equipment Notes to finance a
portion of the purchase price of such Owned Aircraft;

            WHEREAS, as of the Transfer Date, the Related Trustee will assign,
transfer and deliver all of such trustee's right, title and interest to the
trust property held by the Related Trustee to the Trustee pursuant to the
Assignment and Assumption Agreement;

            WHEREAS, the Trustee, effective only, but automatically, upon
execution and delivery of the Assignment and Assumption Agreement, will be
deemed to have declared the creation of the Trust for the benefit of the
Certificateholders, and each Holder of Certificates outstanding as of the
Transfer Date, as the grantors of the Trust, by their respective acceptances of
the Certificates, will join in the creation of this Trust with the Trustee;

            WHEREAS, all Certificates deemed issued by the Trust will evidence
fractional undivided interests in the Trust and will convey no rights, benefits
or interests in respect of any property other than the Trust Property except for
those Certificates to which an Escrow Receipt (as defined below) has been
affixed;
<PAGE>   7
                                      -2-


            WHEREAS, the Company has duly authorized the execution, delivery and
effectiveness of this Agreement as the "issuer", as such term is defined in and
solely for purposes of the Securities Act, of the Certificates deemed to be
issued pursuant hereto and as the "obligor", as such term is defined in and
solely for purposes of the Trust Indenture Act of 1939, as amended, with respect
to all such Certificates and is undertaking to perform certain administrative
and ministerial duties hereunder and is also undertaking to pay the ongoing fees
and expenses of the Trustee;

            WHEREAS, upon the execution and delivery of the Assignment and
Assumption Agreement, all of the conditions and requirements necessary to make
this Agreement a valid, binding and legal instrument, enforceable in accordance
with its terms and for the purposes herein expressed, will have been done,
performed and fulfilled, and the execution and delivery of this Agreement in the
form and with the terms hereof will have been in all respects duly authorized;
and

            WHEREAS, upon issuance of the Exchange Certificates, if any, or the
effectiveness of the Shelf Registration Statement, this Agreement, as amended or
supplemented from time to time, will be subject to the provisions of the Trust
Indenture Act of 1939, and shall, to the extent applicable, be governed by such
provisions;

            NOW, THEREFORE, in consideration of the mutual agreements herein
contained, and of other good and valuable consideration the receipt and adequacy
of which are hereby acknowledged, the parties hereto agree as follows:


                                    ARTICLE I

                                   DEFINITIONS

            Section 1.01. Definitions. For all purposes of this Agreement,
except as otherwise expressly provided or unless the context otherwise requires:

            (1) the terms used in this Agreement, including in the recitals to
this Agreement, that are defined in this Article have the meanings assigned to
them in this Article, and include the plural as well as the singular;

            (2) all other terms used herein which are defined in the Trust
Indenture Act, either directly or by reference therein, or by the rules
promulgated under the Trust Indenture Act, have the meanings assigned to them
therein;

            (3) all references in this Agreement to designated "Articles",
"Sections", "Subsections" and other subdivisions are to the designated Articles,
Sections, Subsections and other subdivisions of this Agreement;

            (4) the words "herein", "hereof" and "hereunder" and other words of
similar import refer to this Agreement as a whole and not to any particular
Article, Section, Subsection or other subdivision; and
<PAGE>   8
                                      -3-


            (5) unless the context otherwise requires, whenever the words
"including", "include" or "includes" are used herein, it shall be deemed to be
followed by the phrase "without limitation".

            Affiliate: Means, with respect to any specified Person, any other
      Person directly or indirectly controlling or controlled by or under direct
      or indirect common control with such Person. For the purposes of this
      definition, "control" means the power, directly or indirectly, to direct
      the management and policies of such Person, whether through the ownership
      of voting securities or by contract or otherwise, and the terms
      "controlling" and "controlled" have meanings correlative to the foregoing.

            Agent Members: Has the meaning specified in Section 3.05.

            Agreement:  Has the meaning specified in the initial paragraph
      hereto.

            Aircraft: Has the meaning specified in the Note Purchase Agreement.

            Aircraft Purchase Agreement: Has the meaning specified in the Note
      Purchase Agreement.

            Assignment and Assumption Agreement: Means the assignment and
      assumption agreement substantially in the form of Exhibit D to the Related
      Trust to be executed and delivered in accordance with Section 11.01 of the
      Related Pass Through Trust Agreement.

            Authorized Agent: Means any Paying Agent or Registrar for the
      Certificates.

            Avoidable Tax: Means a state or local tax (i) upon (w) the Trust,
      (x) the Trust Property, (y) Certificateholders or (z) the Trustee for
      which the Trustee is entitled to seek reimbursement from the Trust
      Property, and (ii) which would be avoided if the Trustee were located in
      another state, or jurisdiction within a state, within the United States. A
      tax shall not be an Avoidable Tax if the Company or any Owner Trustee
      shall agree to pay, and shall pay, such tax.

            AVSA: Means AVSA S.A.R.L., an affiliate of Airbus Industrie G.I.E.

            Business Day: Means any day other than a Saturday, a Sunday or a day
      on which commercial banks are required or authorized to close in Phoenix,
      Arizona, New York, New York, Wilmington, Delaware or, so long as any
      Certificate is outstanding, the city and state in which the Trustee or any
      Loan Trustee maintains its Corporate Trust Office or receives and
      disburses funds.

            Cedel: Means Cedel Bank societe anonyme.

            Certificate: Means any one of the Initial Certificates or Exchange
      Certificates issued by the Related Trust and that are "Outstanding" (as
      defined in the Related Pass Through Trust Agreement) as of the Transfer
      Date (the "Transfer Date Certificates") and 
<PAGE>   9
                                      -4-


      any such Initial Certificates or Exchange Certificates issued in exchange
      therefor or replacement thereof pursuant to this Agreement.

            Certificate Account: Means the account or accounts created and
      maintained pursuant to Section 4.01(a).

            Certificate Purchase Agreement: Means the Purchase Agreement dated
      September 24, 1998 among the Initial Purchasers and the Company, as the
      same may be amended, supplemented or otherwise modified from time to time
      in accordance with its terms.

            Certificateholder or Holder:  Means the Person in whose name a
      Certificate is registered in the Register.

            Class D Certificateholder: Means, at any time, any holder of one or
      more pass through certificates issued by the America West Airlines Pass
      Through Trust, Series 1998-1D, if and when established.

            Company: Means America West Airlines, Inc., a Delaware corporation,
      or its successor in interest pursuant to Section 5.02, or (only in the
      context of provisions hereof, if any, where such reference is required for
      purposes of compliance with the Trust Indenture Act) any other "obligor"
      (within the meaning of the Trust Indenture Act) with respect to the
      Certificates.

            Controlling Party: Has the meaning specified in the Intercreditor
      Agreement.

            Corporate Trust Office: With respect to the Trustee or any Loan
      Trustee, means the office of such trustee in the city at which at any
      particular time its corporate trust business shall be principally
      administered.

            Definitive Certificates: Has the meaning specified in Section
      3.01(e).

            Delivery Period Termination Date: Has the meaning specified in the
      Related Pass Through Trust Agreement.

            Deposits: Has the meaning specified in the Deposit Agreement.

            Deposit Agreement: Means the Deposit Agreement dated as of October
      6, 1998 relating to the Certificates between the Depositary and the Escrow
      Agent, as the same may be amended, supplemented or otherwise modified from
      time to time in accordance with its terms.

            Depositary: Means ABN AMRO Bank N.V., acting through its Chicago
      branch.

            Direction: Has the meaning specified in Section 1.04(a).

            Distribution Date:  Means any Regular Distribution Date or
      Special Distribution Date as the context requires.
<PAGE>   10
                                      -5-


            DTC: Means The Depository Trust Company, its nominees and their
      respective successors.

            EBO Date: Means the date set forth on Schedule 1 to the Lease as the
      "EBO Date".

            Equipment Notes: Means the equipment notes issued under the
      Indentures.

            ERISA: Means the Employee Retirement Income Security Act of 1974, as
      amended from time to time, or any successor federal statute.

            ERISA Legend: Has the meaning specified in Section 3.12.

            Escrow Agent: Means, initially, Wilmington Trust Company, and any
      replacement or successor therefor appointed in accordance with the Escrow
      Agreement.

            Escrow Agreement: Means the Escrow and Paying Agent Agreement dated
      as of October 6, 1998 relating to the Certificates, among the Escrow
      Agent, the Escrow Paying Agent, the Related Trustee (and after the
      Transfer Date, the Trustee) and the Initial Purchasers, as the same may be
      amended, supplemented or otherwise modified from time to time in
      accordance with its terms.

            Escrow Paying Agent: Means the Person acting as paying agent under
      the Escrow Agreement.

            Escrow Receipt: Means the receipt substantially in the form annexed
      to the Escrow Agreement representing a fractional undivided interest in
      the funds held in escrow thereunder.

            Euroclear: Means Morgan Guaranty Trust Company of New York, Brussels
      Office, as operator of the Euroclear System.

            Event of Default: Means an Indenture Default under any Indenture
      pursuant to which Equipment Notes held by the Trust were issued.

            Exchange Certificates: Means the pass through certificates issued in
      exchange for the Initial Certificates pursuant to the Registration Rights
      Agreement and authenticated under the Related Pass Through Trust Agreement
      (prior to the Transfer Date) or hereunder (after the Transfer Date).

            Exchange Offer: Means the exchange offer which may be made pursuant
      to the Registration Rights Agreement to exchange Initial Certificates for
      Exchange Certificates.

            Exchange Offer Registration Statement: Means the registration
      statement that, pursuant to the Registration Rights Agreement, is filed by
      the Company with the SEC with respect to the exchange of Initial
      Certificates for Exchange Certificates.

            Final Legal Distribution Date: Means January 2, 2012.
<PAGE>   11
                                      -6-


            Final Withdrawal: Has the meaning specified in the Escrow Agreement.

            Final Withdrawal Date: Has the meaning specified in the Escrow
      Agreement.

            Financing Documents: With respect to any Equipment Note, means (i)
      the Indenture and the Participation Agreement relating to such Equipment
      Note, and (ii) in the case of any Equipment Note related to a Leased
      Aircraft, the Lease relating to such Leased Aircraft.

            Fractional Undivided Interest: Means the fractional undivided
      interest in the Trust that is evidenced by a Certificate.

            Global Certificates: Has the meaning specified in Section 3.01(d).

            Global Exchange Certificate: Has the meaning specified in Section
      3.01(f).

            Indenture: Means each of the separate trust indentures and mortgages
      relating to the Aircraft, each as specified or described in a Delivery
      Notice delivered pursuant to the Note Purchase Agreement or the related
      Participation Agreement, in each case as the same may be amended,
      supplemented or otherwise modified from time to time in accordance with
      its terms.

            Indenture Default: With respect to any Indenture, means any Event of
      Default (as such term is defined in such Indenture).

            Initial Certificates: Means the "Initial Certificates" issued and
      authenticated under the Related Pass Through Trust Agreement, and any
      certificates issued and authenticated hereunder, in each case, other than
      the Exchange Certificates.

            Initial Purchasers: Means, collectively, Morgan Stanley & Co.
      Incorporated, Donaldson, Lufkin & Jenrette Securities Corporation, Merrill
      Lynch, Pierce, Fenner & Smith Incorporated and Salomon Smith Barney Inc.

            Institutional Accredited Investor: Means an institutional investor
      that is an "accredited investor" within the meaning set forth in Rule
      501(a)(1), (2), (3) or (7) of Regulation D under the Securities Act.

            Intercreditor Agreement: Means the Intercreditor Agreement dated as
      of October 6, 1998 among the Related Trustee (and after the Transfer Date,
      the Trustee), the Related Other Trustees (and after the Transfer Date, the
      Other Trustees), the Liquidity Provider, the liquidity provider relating
      to the Certificates issued under (and as defined in) each of the Related
      Other Pass Through Trust Agreements, and Wilmington Trust Company, as
      Subordination Agent and as trustee thereunder, as amended, supplemented or
      otherwise modified from time to time in accordance with its terms.

            Investors: Means the Initial Purchasers together with all subsequent
      beneficial owners of the Certificates.
<PAGE>   12
                                      -7-


            Issuance Date: Means the date of the issuance of the Initial
      Certificates.

            Lease: Means, with respect to each Leased Aircraft, the lease
      between an Owner Trustee, as the lessor, and the Company, as the lessee,
      referred to in the related Indenture, as such lease may be amended,
      supplemented or otherwise modified in accordance with its terms.

            Leased Aircraft: Has the meaning specified in the second recital to
      this Agreement.

            Liquidity Facility: Means, initially, the Revolving Credit Agreement
      dated as of October 6, 1998 relating to the Certificates, between the
      Liquidity Provider and the Subordination Agent, as agent and trustee for
      the Trustee, and, from and after the replacement of such Agreement
      pursuant to the Intercreditor Agreement, the replacement liquidity
      facility therefor, in each case as amended, supplemented or otherwise
      modified from time to time in accordance with their respective terms.

            Liquidity Provider: Means, initially, ABN AMRO Bank N.V., acting
      through its Chicago branch, and any replacement or successor therefor
      appointed in accordance with the Intercreditor Agreement.

            Loan Trustee: With respect to any Equipment Note or the Indenture
      applicable thereto, means the bank or trust company designated as trustee
      under such Indenture, together with any successor to such trustee
      appointed pursuant thereto.

            Material Adverse Tax Event: Has the meaning specified in Section
      17.3(a)(4) of the Lease.

            Non-U.S. Person: Means a Person that is not a "U.S. person", as
      defined in Regulation S.

            Note Purchase Agreement: Means the Note Purchase Agreement dated as
      of October 6, 1998 among the Related Trustee (and after the Transfer Date,
      the Trustee), the Related Other Trustees (and after the Transfer Date, the
      Other Trustees), the Company, the Escrow Agent, the Escrow Paying Agent
      and the Subordination Agent, as the same may be amended, supplemented or
      otherwise modified from time to time, in accordance with its terms.

            Offering Circular: Means the Offering Memorandum dated September 24,
      1998 relating to the offering of the Certificates and the other
      certificates under the Related Other Pass Through Trust Agreements.

            Officer's Certificate: Means a certificate signed, (a) in the case
      of the Company, by any Vice President or more senior officer of the
      Company or, (b) in the case of an Owner Trustee or a Loan Trustee, a
      Responsible Officer of such Owner Trustee or such Loan Trustee, as the
      case may be.
<PAGE>   13
                                      -8-


            Opinion of Counsel: Means a written opinion of legal counsel who (a)
      in the case of counsel for the Company may be (i) the General Counsel of
      the Company, (ii) Cooley Godward LLP, (iii) Vedder, Price, Kaufman,
      Kammholz & Day, or (iv) such other counsel designated by the Company and
      reasonably acceptable to the Trustee and (b) in the case of counsel for
      any Owner Trustee or any Loan Trustee may be such counsel as may be
      designated by any of them whether or not such counsel is an employee of
      any of them, and who shall be reasonably acceptable to the Trustee.

            Other Pass Through Trust Agreements: Means each of the two other
      America West Airlines 1998-1 Pass Through Trust Agreements relating to
      America West Airlines Pass Through Trust, Series 1998-1A-S and America
      West Airlines Pass Through Trust, Series 1998-1B-S, dated the date hereof.

            Other Trustees: Means the trustees under the Other Pass Through
      Trust Agreements, and any successor or other trustee appointed as provided
      therein.

            Other Trusts: Means the America West Airlines Pass Through Trust,
      Series 1998-1A-S and America West Airlines Pass Through Trust, Series
      1998-1B-S, created under the Other Pass Through Trust Agreements.

            Outstanding: When used with respect to Certificates, means, as of
      the date of determination, all Transfer Date Certificates, and all other
      Certificates theretofore authenticated and delivered under this Agreement,
      in each case except:

                         (i) Certificates theretofore canceled by the Registrar
            or delivered to the Trustee or the Registrar for cancellation;

                         (ii) Certificates for which money in the full amount
            required to make the final distribution with respect to such
            Certificates pursuant to Section 11.01 hereof has been theretofore
            deposited with the Trustee in trust for the Holders of such
            Certificates as provided in Section 4.01 pending distribution of
            such money to such Certificateholders pursuant to payment of such
            final distribution; and

                         (iii) Certificates in exchange for or in lieu of which
            other Certificates have been authenticated and delivered pursuant to
            this Agreement.

            Owned Aircraft: Has the meaning specified in the second recital to
      this Agreement.

            Owner Participant: With respect to any Equipment Note relating to a
      Leased Aircraft, means the "Owner Participant" as referred to in the
      Indenture pursuant to which such Equipment Note is issued and any
      permitted successor or assign of such Owner Participant; and Owner
      Participants at any time of determination means all of the Owner
      Participants thus referred to in the Indentures.

            Owner Trustee: With respect to any Equipment Note relating to a
      Leased Aircraft, means the "Owner Trustee", as referred to in the
      Indenture pursuant to which 
<PAGE>   14
                                      -9-


      such Equipment Note is issued, not in its individual capacity but solely
      as trustee; and Owner Trustees means all of the Owner Trustees party to
      any of the Indentures.

            Participation Agreement: Means each Participation Agreement to be
      entered into by the Related Trustee pursuant to the Note Purchase
      Agreement, as the same may be amended, supplemented or otherwise modified
      in accordance with its terms.

            Paying Agent: Means the paying agent maintained and appointed for
      the Certificates pursuant to Section 7.12.

            Permitted Investments: Means obligations of the United States of
      America or agencies or instrumentalities thereof for the payment of which
      the full faith and credit of the United States of America is pledged,
      maturing in not more than 60 days after the date of acquisition thereof or
      such lesser time as is required for the distribution of any Special
      Payments on a Special Distribution Date.

            Person: Means any person, including any individual, corporation,
      limited liability company, partnership, joint venture, association,
      joint-stock company, trust, trustee, unincorporated organization, or
      government or any agency or political subdivision thereof.

            Pool Balance: Means, as of any date, (i) the original aggregate face
      amount of the "Certificates" as defined in the Related Pass Through Trust
      Agreement, less (ii) the aggregate amount of all payments made in respect
      of such Certificates other than payments made in respect of interest or
      premium thereon or reimbursement of any costs or expenses incurred in
      connection therewith less (iii) the aggregate amount of unused Deposits
      distributed as a Final Withdrawal other than payments in respect of
      interest or premium thereon. The Pool Balance as of any Distribution Date
      shall be computed after giving effect to the payment of principal, if any,
      on the Equipment Notes or other Trust Property held in such Trust and the
      distribution thereof to be made on such Distribution Date and the
      distribution of the Final Withdrawal to be made on such Distribution Date.

            Pool Factor: Means, as of any date, the quotient (rounded to the
      seventh decimal place) computed by dividing (i) the Pool Balance as at
      such date by (ii) the original aggregate face amount of the "Certificates"
      as defined in the Related Pass Through Trust Agreement. The Pool Factor as
      of any Distribution Date shall be computed after giving effect to the
      payment of principal, if any, on the Equipment Notes or other Trust
      Property and the distribution thereof to be made on such Distribution Date
      and the distribution of the Final Withdrawal to be made on such
      Distribution Date.

            PTC Event of Default: Means any failure to pay within 10 Business
      Days of the due date thereof: (i) the outstanding Pool Balance on the
      Final Legal Distribution Date or (ii) interest due on the Certificates on
      any Distribution Date (unless the Subordination Agent shall have made an
      Interest Drawing or Drawings (as defined in the Intercreditor Agreement),
      or a withdrawal or withdrawals pursuant to section 3.6(f) of the
      Intercreditor Agreement, with respect thereto in an aggregate amount
      sufficient to pay such interest and shall have distributed such amount to
      the Trustee).
<PAGE>   15
                                      -10-


            QIB: Means a qualified institutional buyer as defined in Rule 144A.

            Record Date: Means (i) for Scheduled Payments to be distributed on
      any Regular Distribution Date, other than the final distribution, the 15th
      day (whether or not a Business Day) preceding such Regular Distribution
      Date, and (ii) for Special Payments to be distributed on any Special
      Distribution Date, other than the final distribution, the 15th day
      (whether or not a Business Day) preceding such Special Distribution Date.

            Register and Registrar: Mean the register maintained and the
      registrar appointed pursuant to Sections 3.04 and 7.12.

            Registration Event: Means the declaration of the effectiveness by
      the SEC of the Exchange Offer Registration Statement or the Shelf
      Registration Statement.

            Registration Rights Agreement: Means the Exchange and Registration
      Rights Agreement dated as of October 6, 1998, among the Initial
      Purchasers, the Related Trustee (and after the Transfer Date, the
      Trustee), the Related Other Trustees (and after the Transfer Date, the
      Other Trustees) and the Company, as amended, supplemented or otherwise
      modified from time to time in accordance with its terms.

            Regular Distribution Date: With respect to distributions of
      Scheduled Payments in respect of the Certificates, means each date
      designated as a Regular Distribution Date in the Certificates issued
      pursuant to this Agreement, until payment of all the Scheduled Payments to
      be made under the Equipment Notes held in the Trust have been made;
      provided, however, that, if any such day shall not be a Business Day, the
      related distribution shall be made on the next succeeding Business Day
      without additional interest.

            Regulation S: Means Regulation S under the Securities Act or any
      successor regulation thereto.

            Regulation S Definitive Certificates: Has the meaning specified in
      Section 3.01(e).

            Regulation S Global Certificates: Has the meaning specified in
      Section 3.01(d).

            Related Other Pass Through Trust Agreements: Means the "Other Pass
      Through Trust Agreements" as defined in the Related Pass Through Trust
      Agreement.

            Related Other Trustee: Means the "Other Trustees" as defined in the
      Related Pass Through Trust Agreement.

            Related Other Trusts: Means the "Other Trusts" as defined in the
      Related Pass Through Trust Agreement.

            Related Pass Through Trust Agreement: Means the Pass Through Trust
      Agreement relating to America West Airlines Pass Through Trust, Series
      1998-1C-0, dated as of the date hereof, between the Company and the
      institution acting as trustee 
<PAGE>   16
                                      -11-


      thereunder, as amended, supplemented or otherwise modified from time to
      time in accordance with its terms.

            Related Trust: Means the America West Pass Through Trust, Series
      1998-1C-O, formed under the Related Pass Through Trust Agreement.

            Related Trustee: Means the trustee under the Related Pass Through
      Trust Agreement.

            Responsible Officer: With respect to the Trustee, any Loan Trustee
      and any Owner Trustee, means any officer in the Corporate Trust Office of
      the Trustee, Loan Trustee or Owner Trustee or any other officer
      customarily performing functions similar to those performed by the persons
      who at the time shall be such officers, respectively, or to whom any
      corporate trust matter is referred because of his knowledge of and
      familiarity with a particular subject.

            Restricted Definitive Certificates: Has the meaning specified in
      Section 3.01(e).

            Restricted Global Certificate: Has the meaning specified in Section
      3.01(c).

            Restricted Legend: Has the meaning specified in Section 3.02.

            Restricted Period: Has the meaning specified in Section 3.01(d).

            Rule 144A: Means Rule 144A under the Securities Act and any
      successor rule thereto.

            Scheduled Payment: With respect to any Equipment Note, means (i) any
      payment of principal or interest on such Equipment Note (other than any
      such payment which is not in fact received by the Subordination Agent
      within five days of the date on which such payment is scheduled to be
      made) due from the obligor thereon or (ii) any payment of interest on the
      Certificates with funds drawn under any Liquidity Facility, which payment
      represents the installment of principal at the stated maturity of such
      installment of principal on such Equipment Note, the payment of regularly
      scheduled interest accrued on the unpaid principal amount of such
      Equipment Note, or both; provided that any payment of principal, premium,
      if any, or interest resulting from the redemption or purchase of any
      Equipment Note shall not constitute a Scheduled Payment.

            SEC: Means the Securities and Exchange Commission, as from time to
      time constituted or created under the United States Securities Exchange
      Act of 1934, as amended, or, if at any time after the execution of this
      instrument such Commission is not existing and performing the duties now
      assigned to it under the Trust Indenture Act, then the body performing
      such duties on such date.

            Securities Act: Means the United States Securities Act of 1933, as
      amended from time to time, or any successor thereto.
<PAGE>   17
                                      -12-


            Shelf Registration Statement: Means the shelf registration statement
      which may be required to be filed by the Company with the SEC pursuant to
      any Registration Rights Agreement, other than an Exchange Offer
      Registration Statement.

            Special Distribution Date: Means each date on which a Special
      Payment is to be distributed as specified in this Agreement; provided,
      however, that, if any such day shall not be a Business Day, the related
      distribution shall be made on the next succeeding Business Day without
      additional interest.

            Special Redemption Premium: Means the premium payable by the Company
      in respect of the Final Withdrawal pursuant to the Note Purchase
      Agreement.

            Special Payment: Means any payment (other than a Scheduled Payment)
      in respect of, or any proceeds of, any Equipment Note or Trust Indenture
      Estate (as defined in each Indenture) or Special Redemption Premium.

            Special Payments Account: Means the account or accounts created and
      maintained pursuant to Section 4.01(b).

            Subordination Agent: Has the meaning specified in the Intercreditor
      Agreement.

            Substitute Aircraft: Has the meaning specified in the Note Purchase
      Agreement.

            Tax: Means all license, recording, documentary, registration and
      other similar fees and all taxes, levies, imposts, duties, charges,
      assessments or withholdings of any nature whatsoever imposed by any Taxing
      Authority, together with any penalties, additions to tax, fines or
      interest thereon or additions thereto.

            Taxing Authority: Means any federal, state or local government or
      other taxing authority in the United States, any foreign government or any
      political subdivision or taxing authority thereof, any international
      taxing authority or any territory or possession of the United States or
      any taxing authority thereof.

            Transfer Date: Means the moment of execution and delivery of the
      Assignment and Assumption Agreement by each of the parties thereto.

            Transfer Date Certificates: Has the meaning specified in the
      definition of "Certificates".

            Trust: Means the trust created by this Agreement, the estate of
      which consists of the Trust Property.

            Trust Indenture Act: Means the United States Trust Indenture Act of
      1939, as amended from time to time, or any successor thereto.

            Trust Property: Means (i) the Equipment Notes held as the property
      of the Trust and, subject to the Intercreditor Agreement, all monies at
      any time paid thereon and all 
<PAGE>   18
                                      -13-


      monies due and to become due thereunder, (ii) funds from time to time
      deposited in the Certificate Account and the Special Payments Account and,
      subject to the Intercreditor Agreement, any proceeds from the sale by the
      Trustee pursuant to Article VI hereof of any Equipment Note and (iii) all
      rights of the Trust and the Trustee, on behalf of the Trust, under the
      Intercreditor Agreement, the Escrow Agreement, the Note Purchase Agreement
      and the Liquidity Facilities, including, without limitation, all rights to
      receive certain payments thereunder, and all monies paid to the Trustee on
      behalf of the Trust pursuant to the Intercreditor Agreement or the
      Liquidity Facilities, provided, that rights with respect to the Deposits
      or under the Escrow Agreement will not constitute Trust Property.

            Trustee: Means Wilmington Trust Company, or its successor in
      interest, and any successor or other trustee appointed as provided herein.

            Trustee's Lien: Has the meaning specified in Section 7.17.

            Unindemnified Tax: Means (i) any Tax imposed on the net income, net
      worth or capital, any franchise Tax or similar doing business Tax of the
      Pass Through Trustee (other than any such Tax imposed as a result of the
      Company's assumption of the Equipment Notes pursuant to the purchase of an
      aircraft on an EBO Date or a Material Adverse Tax Event), (ii) any
      withholding Tax imposed by the United States (including, without
      limitation, any withholding Tax imposed by the United States which is
      imposed or increased as a result of the Pass Through Trustee failing to
      deliver to the Company any certificate or document necessary to establish
      that payments under this Agreement are exempt from withholding Tax), and
      (iii) any Avoidable Tax.

            Section 1.02. Compliance Certificates and Opinions. Upon any
application or request (except with respect to matters set forth in Article II)
by the Company, any Owner Trustee or any Loan Trustee to the Trustee to take any
action under any provision of this Agreement, the Company, such Owner Trustee or
such Loan Trustee, as the case may be, shall furnish to the Trustee (i) an
Officer's Certificate stating that, in the opinion of the signers, all
conditions precedent, if any, provided for in this Agreement relating to the
proposed action have been complied with and (ii) an Opinion of Counsel stating
that in the opinion of such counsel all such conditions precedent, if any, have
been complied with, except that in the case of any such application or request
as to which the furnishing of such documents is specifically required by any
provision of this Agreement relating to such particular application or request,
no additional certificate or opinion need be furnished.

            Every certificate or opinion with respect to compliance with a
condition or covenant provided for in this Agreement (other than a certificate
provided pursuant to Section 8.04(e)) shall include:

            (1) a statement that each individual signing such certificate or
      opinion has read such covenant or condition and the definitions in this
      Agreement relating thereto;
<PAGE>   19
                                      -14-


            (2) a brief statement as to the nature and scope of the examination
      or investigation upon which the statements or opinions contained in such
      certificate or opinion are based;

            (3) a statement that, in the opinion of each such individual, he has
      made such examination or investigation as is necessary to enable him to
      express an informed opinion as to whether or not such covenant or
      condition has been complied with; and

            (4) a statement as to whether, in the opinion of each such
      individual, such condition or covenant has been complied with.

            Section 1.03. Form of Documents Delivered to Trustee. In any case
where several matters are required to be certified by, or covered by an opinion
of, any specified Person, it is not necessary that all such matters be certified
by, or covered by the opinion of, only one such Person, or that they be so
certified or covered by only one document, but one such Person may certify or
give an opinion with respect to some matters and one or more other such Persons
as to other matters and any such Person may certify or give an opinion as to
such matters in one or several documents.

            Where any Person is required to make, give or execute two or more
applications, requests, consents, certificates, statements, opinions or other
instruments under this Agreement or, in respect of the Certificates, this
Agreement, they may, but need not, be consolidated and form one instrument.

            Section 1.04. Directions of Certificateholders. (a) Any direction,
consent, request, demand, authorization, notice, waiver or other action provided
by this Agreement to be given or taken by Certificateholders (a "Direction") may
be embodied in and evidenced by one or more instruments of substantially similar
tenor signed by such Certificateholders in person or by an agent or proxy duly
appointed in writing; and, except as herein otherwise expressly provided, such
action shall become effective when such instrument or instruments are delivered
to the Trustee and, where it is hereby expressly required pursuant to this
Agreement, to the Company or any Loan Trustee. Proof of execution of any such
instrument or of a writing appointing any such agent or proxy shall be
sufficient for any purpose of this Agreement and conclusive in favor of the
Trustee, the Company and any Loan Trustee, if made in the manner provided in
this Section.

            (b) The fact and date of the execution by any Person of any such
instrument or writing may be proved by the certificate of any notary public or
other officer of any jurisdiction authorized to take acknowledgments of deeds or
administer oaths that the Person executing such instrument acknowledged to him
the execution thereof, or by an affidavit of a witness to such execution sworn
to before any such notary or such other officer and where such execution is by
an officer of a corporation or association or a member of a partnership, on
behalf of such corporation, association or partnership, such certificate or
affidavit shall also constitute sufficient proof of his authority. The fact and
date of the execution of any such instrument or writing, or the authority of the
Person executing the same, may also be proved in any other reasonable manner
which the Trustee deems sufficient.
<PAGE>   20
                                      -15-


            (c) In determining whether the Certificateholders of the requisite
Fractional Undivided Interests of Certificates Outstanding have given any
Direction under this Agreement, Certificates owned by the Company or any
Affiliate thereof shall be disregarded and deemed not to be Outstanding for
purposes of any such determination. In determining whether the Trustee shall be
protected in relying upon any such Direction, only Certificates which the
Trustee knows to be so owned shall be so disregarded. Notwithstanding the
foregoing, (i) if any such Person owns 100% of the Certificates Outstanding,
such Certificates shall not be so disregarded, and (ii) if any amount of
Certificates so owned by any such Person have been pledged in good faith, such
Certificates shall not be disregarded if the pledgee establishes to the
satisfaction of the Trustee the pledgee's right so to act with respect to such
Certificates and that the pledgee is not the Company or any Affiliate thereof.

            (d) For all purposes of this Agreement, all Initial Certificates
constituting Certificates and all Exchange Certificates constituting
Certificates shall vote and take all other actions of Certificateholders
together as one series of Certificates.

            (e) The Company may at its option, by delivery of an Officer's
Certificate to the Trustee, set a record date to determine the
Certificateholders entitled to give any Direction. Notwithstanding Section
316(c) of the Trust Indenture Act, such record date shall be the record date
specified in such Officer's Certificate, which shall be a date not more than 30
days prior to the first solicitation of Certificateholders in connection
therewith. If such a record date is fixed, such Direction may be given before or
after such record date, but only the Certificateholders of record at the close
of business on such record date shall be deemed to be Certificateholders for the
purposes of determining whether Certificateholders of the requisite proportion
of Outstanding Certificates have authorized or agreed or consented to such
Direction, and for that purpose the Outstanding Certificates shall be computed
as of such record date; provided that no such Direction by the
Certificateholders on such record date shall be deemed effective unless it shall
become effective pursuant to the provisions of this Agreement not later than one
year after such record date.

            (f) Any Direction by the Holder of any Certificate shall bind the
Holder of every Certificate issued upon the transfer thereof or in exchange
therefor or in lieu thereof, whether or not notation of such Direction is made
upon such Certificate.

            (g) Except as otherwise provided in Section 1.04(c), Certificates
owned by or pledged to any Person shall have an equal and proportionate benefit
under the provisions of this Agreement, without preference, priority, or
distinction as among all of the Certificates.


                                   ARTICLE II

                          ACQUISITION OF TRUST PROPERTY

            Section 2.01. Acquisition of Trust Property. The Trustee is hereby
irrevocably authorized and directed to execute and deliver the Assignment and
Assumption Agreement on the date specified in Section 11.01 of the Related Pass
Through Trust Agreement, subject only to the satisfaction of the conditions to
such execution set forth in said Section 11.01. This Agreement (except only for
the immediately preceding sentence hereof, which is effective upon 
<PAGE>   21
                                      -16-


execution and delivery hereof) shall become effective upon the execution and
delivery of the Assignment and Assumption Agreement by the Trustee and the
Related Trustee, automatically and without any further signature or action on
the part of the Company and the Trustee, and shall thereupon constitute the
legal, valid and binding obligation of the parties hereto enforceable against
each of the parties hereto in accordance with its terms. Upon such execution and
delivery of the Assignment and Assumption Agreement, the Related Trust shall be
terminated, the Certificateholders shall receive beneficial interests in the
Trust in exchange for their interests in the Related Trust equal to their
respective beneficial interests in the Related Trust and the "Outstanding" (as
defined in the Related Pass Through Trust Agreement) pass through certificates
representing fractional undivided interests in the Related Trust shall be deemed
for all purposes of this Agreement and the Related Pass Through Trust Agreement,
without further signature or action of any party or Certificateholder, to be
Certificates representing the same Fractional Undivided Interests in the Trust
and the Trust Property. By acceptance of its Certificate, each Certificateholder
consents to and ratifies such assignment, transfer and delivery of the trust
property of the Related Trust to the Trustee upon the execution and delivery of
the Assignment and Assumption Agreement.

            Section 2.02. Acceptance by Trustee. The Trustee, upon the execution
and delivery of the Assignment and Assumption Agreement, acknowledges its
acceptance of all right, title and interest in and to the Trust Property and
declares that the Trustee holds and will hold such right, title and interest for
the benefit of all then present and future Certificateholders, upon the trusts
herein set forth. Subject to Section 7.14, the Trustee shall take all actions
reasonably necessary to maintain the registration of all such Equipment Notes in
the name of the Subordination Agent. By the acceptance of each Certificate
issued to it under the Related Pass Through Trust Agreement and deemed issued
under this Agreement, each Holder of any such Certificate as grantor of the
Trust thereby joins in the creation and declaration of the Trust.

            Section 2.03. Limitation of Powers. The Trust is constituted solely
for the purpose of making the investment in the Equipment Notes, and, except as
set forth herein, the Trustee shall not be authorized or empowered to acquire
any other investments or engage in any other activities and, in particular, the
Trustee shall not be authorized or empowered to do anything that would cause
such Trust to fail to qualify as a "grantor trust" for federal income tax
purposes (including as subject to this restriction, acquiring any Aircraft (as
defined in the respective Indentures) by bidding such Equipment Notes or
otherwise, or taking any action with respect to any such Aircraft once
acquired).


                                   ARTICLE III

                                THE CERTIFICATES

            Section 3.01. Title, Form, Denomination and Execution of
Certificates. (a) The Initial Certificates constituting Certificates shall be
known as the "7.84% Initial Pass Through Certificates, Series 1998-1C-S" and the
Exchange Certificates constituting Certificates shall be known as the "7.84%
Exchange Pass Through Certificates, Series 1998-1C-S", in each case, of the
Trust. Each Certificate will represent a fractional undivided interest in the
Trust and shall be substantially in the form set forth as Exhibit A to the
Related Pass Through Trust Agreement, with such appropriate insertions,
omissions, substitutions and other variations as are required or 
<PAGE>   22
                                      -17-


permitted by the Related Pass Through Trust Agreement or this Agreement, as the
case may be, or as the Trustee may deem appropriate to reflect the fact that the
Certificates are being issued hereunder as opposed to the Related Pass Through
Trust Agreement, and may have such letters, numbers or other marks of
identification and such legends or endorsements placed thereon as may be
required to comply with the rules of any securities exchange or as may,
consistently herewith, be determined by the Trustee or the officers executing
such Certificates, as evidenced by the Trustee's or officer's execution of the
Certificates (provided that such letters, numbers or other marks of
identification and such legends or endorsements are in a form acceptable to the
Company). At the Escrow Agent's request under the Escrow Agreement, the Trustee
shall affix the corresponding Escrow Receipt to any Certificate issued
hereunder. Any transfer or exchange of any Certificate shall also effect a
transfer or exchange of the related Escrow Receipt. Prior to the Final
Withdrawal Date, no transfer or exchange of any Certificate shall be permitted
unless the corresponding Escrow Receipt is attached thereto and also is so
transferred or exchanged. By acceptance of any Certificate to which an Escrow
Receipt is attached, each Holder of such a Certificate acknowledges and accepts
the restrictions on transfer of the Escrow Receipt set forth herein and in the
Escrow Agreement.

            (b) The Initial Certificates shall be issued only in fully
registered form without coupons and only in denominations of $100,000 or
integral multiples of $1,000 in excess thereof, except that one Certificate may
be issued in a different denomination. The Exchange Certificates will be issued
in denominations of $1,000 or integral multiples thereof, except that one
Certificate may be issued in a different denomination. Each Certificate shall be
dated the date of its authentication. The aggregate Fractional Undivided
Interest of Certificates shall not at any time exceed $17,705,000.

            (c) The Initial Certificates offered and sold in reliance on Rule
144A shall be in the form of one or more Global Certificates substantially in
the form of Exhibit A to the Related Pass Through Trust Agreement with such
applicable legends as are provided for in Section 3.02 (each a "Restricted
Global Certificate"). Such Restricted Global Certificates shall be in registered
form and be registered in the name of DTC and deposited with the Trustee, at its
Corporate Trust Office, as custodian for DTC. The aggregate principal amount of
any Restricted Global Certificate may from time to time be increased or
decreased by adjustments made on the records of the Trustee, as custodian for
DTC for such Restricted Global Certificate, as provided in Section 3.06 hereof,
which adjustments shall be conclusive as to the aggregate principal amount of
any such Global Certificate.

            (d) The Initial Certificates offered and sold outside the United
States in reliance on Regulation S shall be in the form of one or more global
Certificates substantially in the form of Exhibit A to the Related Pass Through
Trust Agreement (each a "Regulation S Global Certificate"). Such Regulation S
Global Certificates shall be in registered form and be registered in the name of
DTC and deposited with the Trustee, at its Corporate Trust Office, as custodian
for DTC, for credit initially and during the Restricted Period (hereinafter
defined) to the respective accounts of beneficial owners of such Certificates
(or to such other accounts as they may direct) at Morgan Guaranty Trust Company
of New York, Brussels office, as operator of Euroclear or Cedel. As used herein,
the term "Restricted Period", with respect to the Regulation S Global
Certificates offered and sold in reliance on Regulation S, means the period of
40 consecutive days beginning on and including the later of (i) the day on which
the 
<PAGE>   23
                                      -18-


"Certificates" (as defined in the Related Pass Through Trust Agreement are first
offered to persons other than distributors (as defined in Regulation S) in
reliance on Regulation S and (ii) the date of the closing of the offering under
the Certificate Purchase Agreement. The aggregate principal amount of any
Regulation S Global Certificate may from time to time be increased or decreased
by adjustments made on the records of the Trustee, as custodian for DTC for such
Global Certificate, as provided in Section 3.06 hereof, which adjustments shall
be conclusive as to the aggregate principal amount of any such Global
Certificate. The Restricted Global Certificate and Regulation S Global
Certificate are sometimes collectively referred to herein as the "Global
Certificates".

            (e) Initial Certificates offered and sold to any Institutional
Accredited Investor which is not a QIB in a transaction exempt from registration
under the Securities Act (and other than as described in Section 3.01(d)) shall
be substantially in the form of Exhibit A to the Related Pass Through Trust
Agreement in definitive, fully registered form without interest coupons with
such applicable legends as are provided for in Section 3.02 (the "Restricted
Definitive Certificates"). Such Certificates issued pursuant to Section 3.05(b)
in exchange for interests in a Regulation S Global Certificate shall be issued
in definitive, fully registered form without interest coupons (the "Regulation S
Definitive Certificates"). The Restricted Definitive Certificates and the
Regulation S Definitive Certificates are sometimes collectively referred to
herein as the "Definitive Certificates".

            (f) The Exchange Certificates exchanged for Initial Certificates
under the Related Trust shall be in the form of one or more global Certificates
substantially in the form of Exhibit A thereto (each, a "Global Exchange
Certificate"). Exchange Certificates issued under this Trust (each, also a
"Global Exchange Certificate") shall be in the form of one or more global
certificates substantially in the form of Exhibit A to the Related Pass Through
Trust Agreement except that (i) the Restricted Legend (hereinafter defined)
shall be omitted and (ii) such Exchange Certificates shall contain such
appropriate insertions, omissions, substitutions and other variations from the
form set forth in Exhibit A to the Related Pass Through Trust Agreement relating
to the nature of the Exchange Certificates or to reflect the fact that the
Certificates are being issued hereunder as opposed to the Related Pass Through
Trust Agreement, as the Responsible Officer of the Trustee executing such
Exchange Certificates on behalf of the Trust may determine, as evidenced by such
officer's execution on behalf of the Trust of such Exchange Certificates. Such
Global Exchange Certificates shall be in registered form and be registered in
the name of DTC and deposited with the Trustee, at its Corporate Trust Office,
as custodian for DTC. The aggregate principal amount of any Global Exchange
Certificate may from time to time be increased or decreased by adjustments made
on the records of the Trustee, as custodian for DTC for such Global Exchange
Certificate, which adjustments shall be conclusive as to the aggregate principal
amount of any such Global Exchange Certificate. Subject to clause (i) and (ii)
of the second sentence of this Section 3.01(f), the terms hereof applicable to
Restricted Global Certificates and/or Global Certificates shall apply to the
Global Exchange Certificates, mutatis mutandis.

            (g) The Definitive Certificates shall be in registered form and
shall be typed, printed, lithographed or engraved or produced by any combination
of these methods or may be produced in any other manner, all as determined by
the officers executing such Certificates, as evidenced by their execution of
such Certificates.
<PAGE>   24
                                      -19-


            Section 3.02. Restrictive Legends. All Initial Certificates issued
for resale pursuant to Rule 144A or offered and sold to any Institutional
Accredited Investor which is not a QIB (including any Global Certificate issued
upon registration of transfer, in exchange for or in lieu of such Certificates)
shall be "Restricted Certificates" and shall bear a legend to the following
effect (the "Restricted Legend") unless the Company and the Trustee determine
otherwise consistent with applicable law:

            THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE U.S. SECURITIES
      ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND ACCORDINGLY, MAY NOT
      BE OFFERED OR SOLD WITHIN THE UNITED STATES OR TO, OR FOR THE ACCOUNT OR
      BENEFIT OF, ANY PERSONS EXCEPT AS SET FORTH IN THE FOLLOWING SENTENCE. BY
      ITS ACQUISITION HEREOF, THE HOLDER (1) REPRESENTS THAT (A) IT IS A
      "QUALIFIED INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A UNDER THE
      SECURITIES ACT), (B) IT IS AN INSTITUTIONAL "ACCREDITED INVESTOR" (AS
      DEFINED IN RULE 501(a)(1), (2), (3) OR (7) OF REGULATION D UNDER THE
      SECURITIES ACT) (AN "INSTITUTIONAL ACCREDITED INVESTOR") OR (C) IT IS NOT
      A U.S. PERSON AND IS ACQUIRING THIS CERTIFICATE IN AN OFFSHORE TRANSACTION
      IN COMPLIANCE WITH REGULATION S UNDER THE SECURITIES ACT; (2) AGREES THAT
      IT WILL NOT WITHIN TWO YEARS AFTER THE LATER OF THE ORIGINAL ISSUANCE OF
      THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS CERTIFICATE WAS HELD BY
      AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY AFFILIATE OF ANY OF SUCH
      PERSONS RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE EXCEPT (A) TO
      AMERICA WEST AIRLINES, INC., (B) TO A QUALIFIED INSTITUTIONAL BUYER IN
      COMPLIANCE WITH RULE 144A UNDER THE SECURITIES ACT, (C) OUTSIDE THE UNITED
      STATES IN AN OFFSHORE TRANSACTION IN COMPLIANCE WITH RULE 904 UNDER THE
      SECURITIES ACT, (D) PURSUANT TO THE EXEMPTION FROM REGISTRATION PROVIDED
      BY RULE 144 UNDER THE SECURITIES ACT (IF AVAILABLE) OR (E) PURSUANT TO AN
      EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT; AND (3) AGREES
      THAT IF IT SHOULD RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE IT WILL
      DELIVER TO EACH PERSON TO WHOM THIS CERTIFICATE IS TRANSFERRED A NOTICE
      SUBSTANTIALLY TO THE EFFECT OF THIS LEGEND. IN CONNECTION WITH ANY
      TRANSFER OF THIS CERTIFICATE WITHIN TWO YEARS AFTER THE LATER OF THE
      ORIGINAL ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS
      CERTIFICATE WAS HELD BY AMERICA WEST AIRLINES, INC., THE TRUSTEE OR ANY
      AFFILIATE OF ANY OF SUCH PERSONS, THE HOLDER MUST CHECK THE APPROPRIATE
      BOX SET FORTH ON THE REVERSE HEREOF RELATING TO THE MANNER OF SUCH
      TRANSFER AND SUBMIT THIS CERTIFICATE TO THE TRUSTEE. AS USED HEREIN, THE
      TERMS "OFFSHORE TRANSACTION", "UNITED STATES" AND "U.S. PERSON" HAVE THE
      MEANINGS GIVEN TO THEM BY REGULATION S UNDER THE SECURITIES ACT. THE PASS
      THROUGH TRUST AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO
      REFUSE TO REGISTER ANY 
<PAGE>   25
                                      -20-


      TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE FOREGOING RESTRICTIONS.

            Each Global Certificate shall bear the following legend on the face
      thereof:

            UNLESS THIS CERTIFICATE IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE
      OF THE DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), TO THE
      TRUSTEE OR ITS AGENT FOR REGISTRATION OF TRANSFER, EXCHANGE OR PAYMENT,
      AND ANY CERTIFICATE ISSUED IN EXCHANGE FOR THIS CERTIFICATE IS REGISTERED
      IN THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN
      AUTHORIZED REPRESENTATIVE OF DTC (AND ANY PAYMENT HEREON IS MADE TO CEDE &
      CO. OR TO SUCH OTHER ENTITY AS IS REQUESTED BY AN AUTHORIZED
      REPRESENTATIVE OF DTC), ANY TRANSFER, PLEDGE OR OTHER USE HEREOF FOR VALUE
      OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL INASMUCH AS THE REGISTERED
      OWNER HEREOF, CEDE & CO., HAS AN INTEREST HEREIN.

            TRANSFERS OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO TRANSFERS
      IN WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A SUCCESSOR THEREOF OR
      SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL
      CERTIFICATE SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE
      RESTRICTIONS SET FORTH IN SECTIONS 3.05 AND 3.06 OF THE PASS THROUGH TRUST
      AGREEMENT REFERRED TO HEREIN.

            Section 3.03. Authentication of Certificates. (a) No Certificate
shall be entitled to any benefit under this Agreement or be valid or obligatory
for any purpose, unless there appears on such Certificate a certificate of
authentication substantially in the form provided for herein executed by the
Trustee by the manual signature of one of its authorized signatories, and such
certificate upon any Certificate shall be conclusive evidence, and the only
evidence, that such Certificate has been duly authenticated and delivered
hereunder.

            (b) Certificates bearing the manual or facsimile signature of an
individual who was, at the time when such signature was affixed, authorized to
sign on behalf of the Trustee shall be valid and binding obligations of the
Trust notwithstanding that such individual has ceased to be so authorized prior
to the authentication and delivery of such Certificates or did not hold such
office on the date of such Certificates.

            Section 3.04. Transfer and Exchange. The Trustee shall cause to be
kept at the office or agency to be maintained by it in accordance with the
provisions of Section 7.12 a register (the "Register") of the Certificates in
which, subject to such reasonable regulations as it may prescribe, the Trustee
shall provide for the registration of such Certificates and of transfers and
exchanges of such Certificates as herein provided. The Trustee shall initially
be the registrar (the "Registrar") for the purpose of registering such
Certificates and transfers and exchanges of such Certificates as herein
provided. The Company, upon notice to the Trustee, may change the Registrar at
any time.
<PAGE>   26
                                      -21-


            All Certificates issued upon any registration of transfer or
exchange of Certificates shall be valid obligations of the Trust, evidencing the
same interest therein, and entitled to the same benefits under this Agreement,
as the Certificates surrendered upon such registration of transfer or exchange.

            A Certificateholder may transfer a Certificate, or request that a
Certificate be exchanged for Certificates in an aggregate Fractional Undivided
Interest equal to the Fractional Undivided Interest of such Certificate
surrendered for exchange of other authorized denominations, by surrender of such
Certificate to the Trustee with the form of transfer notice thereon duly
completed and executed, and otherwise complying with the terms of this
Agreement, including providing evidence of compliance with any restrictions on
transfer, in form satisfactory to the Trustee and the Registrar; provided that
no exchanges of Initial Certificates for Exchange Certificates shall occur until
an Exchange Offer Registration Statement shall have been declared effective by
the SEC (notice of which shall be provided to the Trustee by the Company). No
such transfer shall be effected until, and such transferee shall succeed to the
rights of a Certificateholder only upon, final acceptance and registration of
the transfer by the Registrar in the Register. Prior to the registration of any
transfer by a Certificateholder as provided herein, the Trustee shall treat the
person in whose name the Certificate is registered as the owner thereof for all
purposes, and the Trustee shall not be affected by notice to the contrary.
Furthermore, DTC shall, by acceptance of a Global Certificate, agree that
transfers of beneficial interests in such Global Certificate may be effected
only through a book-entry system maintained by DTC (or its agent), and that
ownership of a beneficial interest in the Certificate shall be required to be
reflected in book-entry. When Certificates are presented to the Registrar with a
request to register the transfer thereof or to exchange them for other
authorized denominations of a Certificate in a Fractional Undivided Interest
equal to the aggregate Fractional Undivided Interest of Certificates surrendered
for exchange, the Registrar shall register the transfer or make the exchange as
requested if its requirements for such transactions are met.

            To permit registrations of transfers and exchanges in accordance
with the terms, conditions and restrictions hereof, the Trustee shall execute
and authenticate Certificates at the Registrar's request. No service charge
shall be made to a Certificateholder for any registration of transfer or
exchange of Certificates, but the Trustee shall require payment of a sum
sufficient to cover any tax or governmental charge that may be imposed in
connection with any transfer or exchange of Certificates. All Certificates
surrendered for registration of transfer or exchange shall be canceled and
subsequently destroyed by the Trustee.

            Section 3.05. Book-Entry Provisions for Restricted Global
Certificates and Regulation S Global Certificates. (a) Members of, or
participants in, DTC ("Agent Members") shall have no rights under this Agreement
with respect to any Global Certificate held on their behalf by DTC, or the
Trustee as its custodian, and DTC may be treated by the Trustee and any agent of
the Trustee as the absolute owner of such Global Certificate for all purposes
whatsoever. Notwithstanding the foregoing, nothing herein shall prevent the
Trustee or any agent of the Trustee from giving effect to any written
certification, proxy or other authorization furnished by DTC or shall impair, as
between DTC and its Agent Members, the operation of customary practices
governing the exercise of the rights of a holder of any Certificate. Upon the
issuance of any Global Certificate, the Registrar or its duly appointed agent
shall record DTC as the registered holder of such Global Certificate.
<PAGE>   27
                                      -22-


            (b) Transfers of any Global Certificate shall be limited to
transfers of such Restricted Global Certificate or Regulation S Global
Certificate in whole, but not in part, to DTC. Beneficial interests in the
Restricted Global Certificate and any Regulation S Global Certificate may be
transferred in accordance with the rules and procedures of DTC and the
provisions of Section 3.06. Beneficial interests in a Restricted Global
Certificate or a Regulation S Global Certificate shall be (or, under the Related
Pass Through Trust Agreement, may have been) delivered to all beneficial owners
thereof in the form of Restricted Definitive Certificates or Regulation S
Definitive Certificates, as the case may be, if (i) DTC notifies the Trustee
that it is unwilling or unable to continue as depositary for such Restricted
Global Certificate or Regulation S Global Certificate, as the case may be, and a
successor depositary is not appointed by the Trustee within 90 days of such
notice, and (ii) after the occurrence and during the continuance of an Event of
Default, owners of beneficial interests in a Global Certificate with Fractional
Undivided Interests aggregating not less than a majority in interest in the
Trust advise the Trustee, the Company and DTC through Agent Members in writing
that the continuation of a book-entry system through DTC or its successor is no
longer in their best interests.

            (c) Any beneficial interest in one of the Global Certificates that
is transferred to a Person who takes delivery in the form of an interest in
another Global Certificate will, upon such transfer, cease to be an interest in
such Global Certificate and become an interest in the other Global Certificate
and, accordingly, will thereafter be subject to all transfer restrictions, if
any, and other procedures applicable to beneficial interests in such other
Global Certificate for as long as it remains such an interest.

            (d) In connection with the transfer of an entire Restricted Global
Certificate or an entire Regulation S Global Certificate to the beneficial
owners thereof pursuant to paragraph (b) of this Section 3.05, such Restricted
Global Certificate or Regulation S Global Certificate, as the case may be, shall
be deemed to be surrendered to the Trustee for cancellation, and the Trustee
shall execute, authenticate and deliver, to each beneficial owner identified by
DTC in exchange for its beneficial interest in such Restricted Global
Certificate or Regulation S Global Certificate, as the case may be, an equal
aggregate principal amount of Restricted Definitive Certificates or Regulation S
Definitive Certificates, as the case may be, of authorized denominations. None
of the Company, the Registrar, the Paying Agent nor the Trustee shall be liable
for any delay in delivery of such instructions and may conclusively rely on, and
shall be protected in relying on, such registration instructions. Upon the
issuance of Definitive Certificates, the Trustee shall recognize the Person in
whose name the Definitive Certificates are registered in the Register as
Certificateholders hereunder. Neither the Company nor the Trustee shall be
liable if the Trustee or the Company is unable to locate a qualified successor
clearing agency.

            (e) Any Definitive Certificate delivered in exchange for an interest
in the Restricted Global Certificate pursuant to paragraph (b) of this Section
3.05 shall, except as otherwise provided by paragraph (e) of Section 3.06, bear
the Restricted Legend.

            (f) Prior to the expiration of the Restricted Period, any Regulation
S Definitive Certificate delivered in exchange for an interest in a Regulation S
Global Certificate pursuant to paragraph (b) of this Section shall bear the
Restricted Legend.
<PAGE>   28
                                      -23-


            (g) The registered holder of any Restricted Global Certificate or
Regulation S Global Certificate may grant proxies and otherwise authorize any
Person, including Agent Members and Persons that may hold interests through
Agent Members, to take any action which a Holder is entitled to take under this
Agreement or the Certificates.

            Section 3.06. Special Transfer Provisions. Unless and until (i) an
Initial Certificate is sold under an effective Shelf Registration Statement, or
(ii) an Initial Certificate is exchanged for an Exchange Certificate pursuant to
an effective Exchange Offer Registration Statement, in each case pursuant to the
terms of the Registration Rights Agreement, the following provisions shall apply
to such Initial Certificates:

            (a) Transfers to Non-QIB Institutional Accredited Investors. The
      following provisions shall apply with respect to the registration of any
      proposed transfer of a Certificate to any Institutional Accredited
      Investor which is neither a QIB nor a Non-U.S. Person:

                         (i) The Registrar shall register the transfer of any
            Certificate, whether or not bearing the Restricted Legend, only if
            (x) the requested transfer is at least two years after the later of
            the original issue date of the Certificates and the last date on
            which such Certificate was held by the Company, the Trustee or any
            affiliate of any of such Persons or (y) the proposed transferor is
            an Initial Purchaser who is transferring Certificates purchased
            under the Certificates Purchase Agreement and the proposed
            transferee has delivered to the Registrar a letter substantially in
            the form of Exhibit B hereto and the aggregate principal amount of
            the Certificates being transferred is at least $100,000. Except as
            provided in the foregoing clause (y), the Registrar shall not
            register the transfer of any Certificate to any Institutional
            Accredited Investor which is neither a QIB nor a Non-U.S. Person.

                         (ii) If the proposed transferor is an Agent Member
            holding a beneficial interest in a Restricted Global Certificate,
            upon receipt by the Registrar of (x) the documents, if any, required
            by paragraph (i) and (y) instructions given in accordance with DTC's
            and the Registrar's procedures, the Registrar shall reflect on its
            books and records the date of the transfer and a decrease in the
            principal amount of such Restricted Global Certificate in an amount
            equal to the principal amount of the beneficial interest in such
            Restricted Global Certificate to be transferred, and the Trustee
            shall execute, authenticate and deliver to the transferor or at its
            direction, one or more Restricted Definitive Certificates of like
            tenor and amount.

            (b) Transfers to QIBs. The following provisions shall apply with
      respect to the registration of any proposed transfer of an Initial
      Certificate to a QIB (excluding Non-U.S. Persons):

                         (i) If the Certificate to be transferred consists of
            Restricted Definitive Certificates, or of an interest in any
            Regulation S Global Certificate during the Restricted Period, the
            Registrar shall register the transfer if such 
<PAGE>   29
                                      -24-


            transfer is being made by a proposed transferor who has checked the
            box provided for on the form of Initial Certificate stating, or has
            otherwise advised the Trustee and the Registrar in writing, that the
            sale has been made in compliance with the provisions of Rule 144A to
            a transferee who has signed the certification provided for on the
            form of Initial Certificate stating, or has otherwise advised the
            Trustee and the Registrar in writing, that it is purchasing the
            Initial Certificate for its own account or an account with respect
            to which it exercises sole investment discretion and that it, or the
            Person on whose behalf it is acting with respect to any such
            account, is a QIB within the meaning of Rule 144A, and is aware that
            the sale to it is being made in reliance on Rule 144A and
            acknowledges that it has received such information regarding the
            Trust and/or the Company as it has requested pursuant to Rule 144A
            or has determined not to request such information and that it is
            aware that the transferor is relying upon its foregoing
            representations in order to claim the exemption from registration
            provided by Rule 144A.

                         (ii) Upon receipt by the Registrar of the documents
            required by clause (i) above and instructions given in accordance
            with DTC's and the Registrar's procedures therefor, the Registrar
            shall reflect on its books and records the date of such transfer and
            an increase in the principal amount of a Restricted Global
            Certificate in an amount equal to the principal amount of the
            Restricted Definitive Certificates or interests in such Regulation S
            Global Certificate, as the case may be, being transferred, and the
            Trustee shall cancel such Definitive Certificates or decrease the
            amount of such Regulation S Global Certificate so transferred.

            (c) Transfers of Interests in the Regulation S Global Certificate or
      Regulation S Definitive Certificates. After the expiration of the
      Restricted Period, the Registrar shall register any transfer of interests
      in any Regulation S Global Certificate or Regulation S Definitive
      Certificates without requiring any additional certification. Until the
      expiration of the Restricted Period, interests in the Regulation S Global
      Certificate may only be held through Agent Members acting for and on
      behalf of Euroclear and Cedel.

            (d) Transfers to Non-U.S. Persons at Any Time. The following
      provisions shall apply with respect to any registration of any transfer of
      an Initial Certificate to a Non-U.S. Person:

                         (i) Prior to the expiration of the Restricted Period,
            the Registrar shall register any proposed transfer of an Initial
            Certificate to a Non-U.S.Person upon receipt of a certificate
            substantially in the form set forth as Exhibit A hereto from the
            proposed transferor.

                         (ii) After the expiration of the Restricted Period, the
            Registrar shall register any proposed transfer to any Non-U.S.
            Person if the Certificate to be transferred is a Restricted
            Definitive Certificate or an interest in a Restricted Global
            Certificate, upon receipt of a certificate substantially in the form
            of Exhibit A from the proposed transferor. The Registrar shall
            promptly send a copy of such certificate to the Company.
<PAGE>   30
                                      -25-


                         (iii) Upon receipt by the Registrar of (x) the
            documents, if any, required by clause (ii) and (y) instructions in
            accordance with DTC's and the Registrar's procedures, the Registrar
            shall reflect on its books and records the date of such transfer and
            a decrease in the principal amount of such Restricted Global
            Certificate in an amount equal to the principal amount of the
            beneficial interest in such Restricted Global Certificate to be
            transferred, and, upon receipt by the Registrar of instructions
            given in accordance with DTC's and the Registrar's procedures, the
            Registrar shall reflect on its books and records the date and an
            increase in the principal amount of the Regulation S Global
            Certificate in an amount equal to the principal amount of the
            Restricted Definitive Certificate or the Restricted Global
            Certificate, as the case may be, to be transferred, and the Trustee
            shall cancel the Definitive Certificate, if any, so transferred or
            decrease the amount of such Restricted Global Certificate.

            (e) Restricted Legend. Upon the transfer, exchange or replacement of
      Certificates not bearing the Restricted Legend, the Registrar shall
      deliver Certificates that do not bear the Restricted Legend. Upon the
      transfer, exchange or replacement of Certificates bearing the Restricted
      Legend, the Registrar shall deliver only Certificates that bear the
      Restricted Legend unless either (i) the circumstances contemplated by
      paragraph (d)(ii) of this Section 3.06 exist or (ii) there is delivered to
      the Registrar an Opinion of Counsel to the effect that neither such legend
      nor the related restrictions on transfer are required in order to maintain
      compliance with the provisions of the Securities Act.

            (f) General. By acceptance of any Certificate bearing the Restricted
      Legend, each Holder of such a Certificate acknowledges the restrictions on
      transfer of such Certificate set forth in this Agreement and agrees that
      it will transfer such Certificate only as provided in this Agreement. The
      Registrar shall not register a transfer of any Certificate unless such
      transfer complies with the restrictions on transfer, if any, of such
      Certificate set forth in this Agreement. In connection with any transfer
      of Certificates, each Certificateholder agrees by its acceptance of the
      Certificates to furnish the Registrar or the Trustee such certifications,
      legal opinions or other information as either of them may reasonably
      require to confirm that such transfer is being made pursuant to an
      exemption from, or a transaction not subject to, the registration
      requirements of the Securities Act and in accordance with the terms and
      provisions of this Article III; provided that the Registrar shall not be
      required to determine the sufficiency of any such certifications, legal
      opinions or other information.

            Until such time as no Certificates remain Outstanding, the Registrar
shall retain copies of all letters, notices and other written communications
received pursuant to Section 3.05 or this Section 3.06. The Trustee, if not the
Registrar at such time, shall have the right to inspect and make copies of all
such letters, notices or other written communications at any reasonable time
upon the giving of reasonable written notice to the Registrar.

            Section 3.07. Mutilated, Destroyed, Lost or Stolen Certificates. If
(a) any mutilated Certificate is surrendered to the Registrar or the Registrar
receives evidence to its satisfaction of the destruction, loss or theft of any
Certificate and (b) there is delivered to the 
<PAGE>   31
                                      -26-


Registrar and the Trustee such security, indemnity or bond, as may be required
by them to save each of them harmless, then, in the absence of notice to the
Registrar or the Trustee that such destroyed, lost or stolen Certificate has
been acquired by a protected purchaser, and provided that the requirements of
Section 8-405 of the Uniform Commercial Code in effect in any applicable
jurisdiction are met, the Trustee shall execute, authenticate and deliver, in
exchange for or in lieu of any such mutilated, destroyed, lost or stolen
Certificate, a new Certificate or Certificates, in authorized denominations and
of like Fractional Undivided Interest and bearing a number not contemporaneously
outstanding.

            In connection with the issuance of any new Certificate under this
Section 3.07, the Trustee may require the payment of a sum sufficient to cover
any tax or other governmental charge that may be imposed in relation thereto and
any other expenses (including the fees and expenses of the Trustee and the
Registrar) connected therewith.

            Any duplicate Certificate issued pursuant to this Section 3.07 shall
constitute conclusive evidence of the appropriate Fractional Undivided Interest
in the Trust, as if originally issued, whether or not the lost, stolen or
destroyed Certificate shall be found at any time.

            The provisions of this Section are exclusive and shall preclude (to
the extent lawful) all other rights and remedies with respect to the replacement
or payment of mutilated, destroyed, lost or stolen Certificates.

            Section 3.08. Persons Deemed Owners. Prior to due presentment of a
Certificate for registration of transfer, the Trustee, the Registrar and any
Paying Agent may treat the Person in whose name any Certificate is registered
(as of the day of determination) as the owner of such Certificate for the
purpose of receiving distributions pursuant to Article IV and for all other
purposes whatsoever, and none of the Trustee, the Registrar or any Paying Agent
shall be affected by any notice to the contrary.

            Section 3.09. Cancellation. All Certificates surrendered for payment
or transfer or exchange shall, if surrendered to the Trustee or any agent of the
Trustee other than the Registrar, be delivered to the Registrar for cancellation
and shall promptly be canceled by it. No Certificates shall be authenticated in
lieu of or in exchange for any Certificates canceled as provided in this
Section, except as expressly permitted by this Agreement. All canceled
Certificates held by the Registrar shall be destroyed and a certification of
their destruction delivered to the Trustee.

            Section 3.10. Temporary Certificates. Until definitive Certificates
are ready for delivery, the Trustee shall authenticate temporary Certificates.
Temporary Certificates shall be substantially in the form of definitive
Certificates but may have insertions, substitutions, omissions and other
variations determined to be appropriate by the officers executing the temporary
Certificates, as evidenced by their execution of such temporary Certificates. If
temporary Certificates are issued, the Trustee will cause definitive
Certificates to be prepared without unreasonable delay. After the preparation of
definitive Certificates, the temporary Certificates shall be exchangeable for
definitive Certificates upon surrender of the temporary Certificates at the
office or agency of the Trustee designated for such purpose pursuant to Section
7.12, without charge to the Certificateholder. Upon surrender for cancellation
of any one 
<PAGE>   32
                                      -27-


or more temporary Certificates, the Trustee shall execute, authenticate and
deliver in exchange therefor a like face amount of definitive Certificates of
authorized denominations. Until so exchanged, the temporary Certificates shall
be entitled to the same benefits under this Agreement as definitive
Certificates.

            Section 3.11. Limitation of Liability for Payments. All payments and
distributions made to Certificateholders in respect of the Certificates shall be
made only from the Trust Property and only to the extent that the Trustee shall
have sufficient income or proceeds from the Trust Property to make such payments
in accordance with the terms of Article IV of this Agreement. Each
Certificateholder, by its acceptance of a Certificate, agrees that it will look
solely to the income and proceeds from the Trust Property for any payment or
distribution due to such Certificateholder pursuant to the terms of this
Agreement and that it will not have any recourse to the Company, the Trustee,
the Loan Trustees, the Liquidity Providers, the Owner Trustees or the Owner
Participants, except as otherwise expressly provided herein or in the
Intercreditor Agreement.

The Company is a party to this Agreement solely for purposes of meeting the
requirements of the Trust Indenture Act, and therefore shall not have any right,
obligation or liability hereunder (except as otherwise expressly provided
herein).

            Section 3.12 ERISA Restrictive Legend. All Certificates issued
pursuant to this Agreement shall bear a legend to the following effect (the
"ERISA Legend") unless the Company and the Trustee determine otherwise
consistent with applicable law:

            "BY ITS ACQUISITION HEREOF, THE HOLDER REPRESENTS THAT (A) NO PLAN
ASSETS HAVE BEEN USED TO PURCHASE THIS CERTIFICATE OR AN INTEREST HEREIN OR (B)
THE PURCHASE AND HOLDING OF THIS CERTIFICATE OR AN INTEREST HEREIN IS EXEMPT
FROM THE PROHIBITED TRANSACTION RESTRICTIONS OF ERISA AND THE CODE PURSUANT TO
ONE OR MORE PROHIBITED TRANSACTION STATUTORY OR ADMINISTRATIVE EXEMPTIONS. THE
PASS THROUGH TRUST AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO
REFUSE TO REGISTER ANY TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE
FOREGOING RESTRICTIONS."

            By acceptance of any Certificate bearing the ERISA Legend, each
Holder of such a Certificate acknowledges the restrictions on transfer of such
Certificate set forth in this Agreement and agrees that it will transfer such
Certificate only as provided in this Agreement. The Trustee shall not register a
transfer of any Certificate unless such transfer complies with the restrictions
on transfer, if any, of such Certificate set forth in such legend.

<PAGE>   33
                                      -28-

                                   ARTICLE IV

                          DISTRIBUTIONS; STATEMENTS TO
                               CERTIFICATEHOLDERS

            Section 4.01. Certificate Account and Special Payments Account. (a)
The Trustee shall maintain on behalf of the Certificateholders a Certificate
Account as one or more non-interest-bearing accounts. The Trustee shall hold the
Certificate Account in trust for the benefit of the Certificateholders, and
shall make or permit withdrawals therefrom only as provided in this Agreement.
On each day when a Scheduled Payment is made to the Trustee under the
Intercreditor Agreement, the Trustee upon receipt thereof shall immediately
deposit the aggregate amount of such Scheduled Payment in the Certificate
Account.

            (b) The Trustee shall maintain on behalf of the Certificateholders a
Special Payments Account as one or more accounts, which shall be non-interest
bearing except as provided in Section 4.04. The Trustee shall hold the Special
Payments Account in trust for the benefit of the Certificateholders and shall
make or permit withdrawals therefrom only as provided in this Agreement. On each
day when one or more Special Payments are made to the Trustee under the
Intercreditor Agreement and upon the payment of the Special Redemption Premium
to the Trustee under the Note Purchase Agreement, the Trustee, upon receipt
thereof, shall immediately deposit the aggregate amount of such Special Payments
in the Special Payments Account.

            (c) The Trustee shall cause the Subordination Agent to present to
the related Loan Trustee of each Equipment Note such Equipment Note on the date
of its stated final maturity or, in the case of any Equipment Note which is to
be redeemed in whole pursuant to the related Indenture, on the applicable
redemption date under such Indenture.

            Section 4.02. Distributions from Certificate Account and Special
Payments Account. (a) On each Regular Distribution Date or as soon thereafter as
the Trustee has confirmed receipt of the payment of all or any part of the
Scheduled Payments due on such date, the Trustee shall distribute out of the
Certificate Account the entire amount deposited therein pursuant to Section
4.01(a). There shall be so distributed to each Certificateholder of record on
the Record Date with respect to such Regular Distribution Date (other than as
provided in Section 11.01 concerning the final distribution) by check mailed to
such Certificateholder, at the address appearing in the Register, such
Certificateholder's pro rata share (based on the Fractional Undivided Interest
in the Trust held by such Certificateholder) of the total amount in the
Certificate Account, except that, with respect to Certificates registered on the
Record Date in the name of DTC, such distribution shall be made by wire transfer
in immediately available funds to the account designated by DTC.

            (b) On each Special Distribution Date with respect to any Special
Payment or as soon thereafter as the Trustee has confirmed receipt of any
Special Payments due on the Equipment Notes held in the related Trust or
realized upon the sale of such Equipment Notes or receipt of the Special
Redemption Premium, the Trustee shall distribute out of the Special Payments
Account the entire amount of such Special Payment deposited therein pursuant to
Section 4.01(b). There shall be so distributed to each Certificateholder of
record on the Record Date with respect to such Special Distribution Date (other
than as provided in Section 11.01 concerning the final distribution) by check
mailed to such Certificateholder, at the address 
<PAGE>   34
                                      -29-


appearing in the Register, such Certificateholder's pro rata share (based on the
Fractional Undivided Interest in the Trust held by such Certificateholder) of
the total amount in the Special Payments Account on account of such Special
Payment, except that, with respect to Certificates registered on the Record Date
in the name of DTC, such distribution shall be made by wire transfer in
immediately available funds to the account designated by DTC.

            (c) The Trustee shall cause notice of each Special Payment to be
mailed to each Certificateholder at his address as it appears in the Register.
In the event of redemption or purchase of Equipment Notes held in the Trust,
such notice shall be mailed not less than 20 days prior to the Special
Distribution Date for the Special Payment resulting from such redemption or
purchase, which Special Distribution Date shall be the date of such redemption
or purchase. In the event of the payment of a Special Redemption Premium by the
Company to the Trustee under the Note Purchase Agreement, such notice shall be
mailed, together with the notice by the Escrow Paying Agent under Section 2.06
of the Escrow Agreement, not less than 20 days prior to the Special Distribution
Date for such amount, which Special Distribution Date shall be the Final
Withdrawal Date. In the case of any other Special Payments, such notice shall be
mailed as soon as practicable after the Trustee has confirmed that it has
received funds for such Special Payment, stating the Special Distribution Date
for such Special Payment which shall occur not less than 20 days after the date
of such notice and as soon as practicable thereafter. Notices mailed by the
Trustee shall set forth:

                         (i) the Special Distribution Date and the Record Date
            therefor (except as otherwise provided in Section 11.01),

                         (ii) the amount of the Special Payment for each $1,000
            face amount Certificate and the amount thereof constituting
            principal, premium, if any, and interest,

                         (iii) the reason for the Special Payment, and

                         (iv) if the Special Distribution Date is the same date
            as a Regular Distribution Date, the total amount to be received on
            such date for each $1,000 face amount Certificate.

If the amount of (i) premium, if any, payable upon the redemption or purchase of
an Equipment Note or (ii) the Special Redemption Premium, if any, has not been
calculated at the time that the Trustee mails notice of a Special Payment, it
shall be sufficient if the notice sets forth the other amounts to be distributed
and states that any premium received will also be distributed.

            If any redemption of the Equipment Notes held in the Trust is
canceled, the Trustee, as soon as possible after learning thereof, shall cause
notice thereof to be mailed to each Certificateholder at its address as it
appears on the Register.

            Section 4.03. Statements to Certificateholders. (a) On each
Distribution Date, the Trustee will include with each distribution to
Certificateholders of a Scheduled Payment or Special Payment, as the case may
be, a statement setting forth the information provided below (in the case of a
Special Payment, including any Special Redemption Premium, reflecting in part
the information provided by the Escrow Paying Agent under the Escrow Agreement).
Such 
<PAGE>   35
                                      -30-


statement shall set forth (per $1,000 face amount Certificate as to (ii), (iii),
(iv) and (v) below) the following information:

            (i) the aggregate amount of funds distributed on such Distribution
      Date hereunder and under the Escrow Agreement, indicating the amount
      allocable to each source;

            (ii) the amount of such distribution hereunder allocable to
      principal and the amount allocable to premium (including the Special
      Redemption Premium), if any;

            (iii) the amount of such distribution hereunder allocable to
      interest; and

            (iv) the amount of such distribution under the Escrow Agreement
      allocable to interest;

            (v) the amount of such distribution under the Escrow Agreement
      allocable to Deposits; and

            (vi) the Pool Balance and the Pool Factor.

            With respect to the Certificates registered in the name of DTC, on
the Record Date prior to each Distribution Date, the Trustee will request from
DTC a securities position listing setting forth the names of all Agent Members
reflected on DTC's books as holding interests in the Certificates on such Record
Date. On each Distribution Date, the Trustee will mail to each such Agent Member
the statement described above and will make available additional copies as
requested by such Agent Member for forwarding to holders of interests in the
Certificates.

            (b) Within a reasonable period of time after the end of each
calendar year but not later than the latest date permitted by law, the Trustee
shall furnish to each Person who at any time during such calendar year was a
Certificateholder of record a statement containing the sum of the amounts
determined pursuant to clauses (a)(i), (a)(ii), (a)(iii), (a)(iv) and (a)(v)
above for such calendar year or, in the event such Person was a
Certificateholder of record during a portion of such calendar year, for such
portion of such year, and such other items as are readily available to the
Trustee and which a Certificateholder shall reasonably request as necessary for
the purpose of such Certificateholder's preparation of its federal income tax
returns. Such statement and such other items shall be prepared on the basis of
information supplied to the Trustee by the Agent Members and shall be delivered
by the Trustee to such Agent Members to be available for forwarding by such
Agent Members to the holders of interests in the Certificates in the manner
described in Section 4.03(a).

            (c) Promptly following (i) the Transfer Date, if there has been any
change in the information set forth in clauses (x), (y) and (z) below from that
set forth in page 69 of the Offering Circular, and (ii) any early redemption or
purchase of, or any default in the payment of principal or interest in respect
of, any of the Equipment Notes held in the Trust, or any Final Withdrawal, the
Trustee shall furnish to Certificateholders of record on such date a statement
setting forth (x) the expected Pool Balances for each subsequent Regular
Distribution Dates following the Delivery Period Termination Date, (y) the
related Pool Factors for such Regular Distribution Dates and (z) the expected
principal distribution schedule of the Equipment Notes, 
<PAGE>   36
                                      -31-


in the aggregate, held as Trust Property at the date of such notice. With
respect to the Certificates registered in the name of DTC, on the Transfer Date,
the Trustee will request from DTC a securities position listing setting forth
the names of all Agent Members reflected on DTC's books as holding interests in
the "Certificates" (as defined in the Related Pass Through Trust Agreement) on
the Delivery Period Termination Date. The Trustee will mail to each such Agent
Member the statement described above and will make available additional copies
as requested by such Agent Member for forwarding to holders of interests in the
Certificates.

            Section 4.04. Investment of Special Payment Moneys. Any money
received by the Trustee pursuant to Section 4.01(b) representing a Special
Payment which is not distributed on the date received shall, to the extent
practicable, be invested in Permitted Investments by the Trustee pending
distribution of such Special Payment pursuant to Section 4.02. Any investment
made pursuant to this Section 4.04 shall be in such Permitted Investments having
maturities not later than the date that such moneys are required to be used to
make the payment required under Section 4.02 on the applicable Special
Distribution Date and the Trustee shall hold any such Permitted Investments
until maturity. The Trustee shall have no liability with respect to any
investment made pursuant to this Section 4.04, other than by reason of the
willful misconduct or negligence of the Trustee. All income and earnings from
such investments shall be distributed on such Special Distribution Date as part
of such Special Payment.


                                    ARTICLE V

                                   THE COMPANY

            Section 5.01. Maintenance of Corporate Existence. The Company, at
its own cost and expense, will do or cause to be done all things necessary to
preserve and keep in full force and effect its corporate existence, except as
permitted by Section 5.02.

            Section 5.02. Consolidation, Merger, Etc. The Company shall not
consolidate with or merge into any other corporation or convey, transfer or
lease substantially all of its assets as an entirety to any Person unless:

            (a) the corporation formed by such consolidation or into which the
      Company is merged or the Person that acquires by conveyance, transfer or
      lease substantially all of the assets of the Company as an entirety shall
      be (i) organized and validly existing under the laws of the United States
      of America or any state thereof or the District of Columbia, (ii) a
      "citizen of the United States" as defined in 49 U.S.C. 40102(a)(15), as
      amended, and (iii) a United States certificated air carrier, if and so
      long as such status is a condition of entitlement to the benefits of
      Section 1110 of the Bankruptcy Reform Act of 1978, as amended (11 U.S.C.
      Section 1110);

            (b) the corporation formed by such consolidation or into which the
      Company is merged or the Person which acquires by conveyance, transfer or
      lease substantially all of the assets of the Company as an entirety shall
      execute and deliver to the Trustee a duly authorized, valid, binding and
      enforceable agreement in form and substance reasonably satisfactory to the
      Trustee containing an assumption by such successor corporation or Person
      of the due and punctual performance and observance of each covenant and
<PAGE>   37
                                      -32-


      condition of this Agreement, the Other Pass Through Trust Agreements and
      each Financing Document to be performed or observed by the Company; and

            (c) the Company shall have delivered to the Trustee an Officer's
      Certificate of the Company reasonably satisfactory to the Trustee, stating
      that such consolidation, merger, conveyance, transfer or lease and the
      assumption agreement mentioned in clause (b) above comply with this
      Section 5.02 and that all conditions precedent herein provided for
      relating to such transaction have been complied with.

            Upon any consolidation or merger, or any conveyance, transfer or
lease of substantially all of the assets of the Company as an entirety in
accordance with this Section 5.02, the successor corporation or Person formed by
such consolidation or into which the Company is merged or to which such
conveyance, transfer or lease is made shall succeed to, and be substituted for,
and may exercise every right and power of, the Company under this Agreement with
the same effect as if such successor corporation or Person had been named as the
Company herein. No such conveyance, transfer or lease of substantially all of
the assets of the Company as an entirety shall have the effect of releasing any
successor corporation or Person which shall have become such in the manner
prescribed in this Section 5.02 from its liability in respect of this Agreement
and any Financing Document to which it is a party.


                                   ARTICLE VI

                                     DEFAULT

            Section 6.01. Events of Default. (a) Exercise of Remedies. Upon the
occurrence and during the continuation of any Indenture Default under any
Indenture, the Trustee may, to the extent it is the Controlling Party at such
time (as determined pursuant to the Intercreditor Agreement), direct the
exercise of remedies as provided in the Intercreditor Agreement.

            (b) Purchase Rights of Certificateholders. (i) At any time after the
      occurrence and during the continuance of a Triggering Event, each
      Certificateholder shall have the right (which shall not expire upon any
      purchase of the Class A Certificates pursuant to the Class B Trust
      Agreement) to purchase, for the purchase prices set forth in the Class A
      Trust Agreement and the Class B Trust Agreement, respectively, all, but
      not less than all, of the Class A Certificates and the Class B
      Certificates upon ten days' written notice to the Class A Trustee, the
      Class B Trustee and each other Certificateholder, provided that (i) if
      prior to the end of such ten-day period any other Certificateholder
      notifies such purchasing Certificateholder that such other
      Certificateholder wants to participate in such purchase, then such other
      Certificateholder may join with the purchasing Certificateholder to
      purchase all, but not less than all, of the Class A Certificates and the
      Class B Certificates pro rata based on the Fractional Undivided Interest
      in the Trust held by each such Certificateholder and (ii) if prior to the
      end of such ten-day period any other Certificateholder fails to notify the
      purchasing Certificateholder of such other Certificateholder's desire to
      participate in such a purchase, then such other Certificateholder shall
      lose its right to purchase the Class A Certificates and the Class B
      Certificates pursuant to this Section 6.01(b); and
<PAGE>   38
                                      -33-


            (ii) by acceptance of its Certificate, each Certificateholder agrees
      that at any time after the occurrence and during the continuation of a
      Triggering Event, each Class D Certificateholder shall have the right
      (which shall not expire upon any purchase of the Class A Certificates
      pursuant to the Class B Trust Agreement or any purchase of the Class A
      Certificates and the Class B Certificates pursuant to clause (b)(i) above)
      to purchase all, but not less than all, of the Class A Certificates, the
      Class B Certificates and the Certificates upon ten days' written notice to
      the Class A Trustee, the Class B Trustee, the Trustee and each other Class
      D Certificateholder, provided that (A) if prior to the end of such ten-day
      period any other Class D Certificateholder notifies such purchasing Class
      D Certificateholder that such other Class D Certificateholder wants to
      participate in such purchase, then such other Class D Certificateholder
      may join with the purchasing Class D Certificateholder to purchase all,
      but not less than all, of the Class A Certificates, the Class B
      Certificates and the Certificates pro rata based on the Fractional
      Undivided Interest in the Class D Trust, taken as a whole, held by each
      such Class D Certificateholder and (B) if prior to the end of such ten day
      period any other Class D Certificateholder fails to notify the purchasing
      Class D Certificateholder of such other Class D Certificateholder's desire
      to participate in such a purchase, then such other Class D
      Certificateholder shall lose its right to purchase the Certificates
      pursuant to this Section 6.01(b).

            The purchase price with respect to the Certificates shall be equal
to the Pool Balance of the Certificates, together with accrued and unpaid
interest thereon to the date of such purchase, without premium, but including
any other amounts then due and payable to the Certificateholders under this
Agreement, the Intercreditor Agreement, the Escrow Agreement or any Financing
Document or on or in respect of the Certificates; provided, however, that (i) if
such purchase occurs after the record date specified in Section 2.03(b) of the
Escrow Agreement relating to the distribution of unused Deposits and accrued and
unpaid interest thereunder, such purchase price shall be reduced by the
aggregate amount of unused deposits and interest to be distributed under the
Escrow Agreement (which deducted amounts shall remain distributable to, and may
be retained by, the Certificateholder as of such Record Date) and (ii) if such
purchase occurs after a Record Date, such purchase price shall be reduced by the
amount to be distributed hereunder on the related Distribution Date (which
deducted amounts shall remain distributable to, and may be retained by, the
Certificateholder as of such Record Date); provided further, that no such
purchase of Certificates shall be effective unless the purchaser(s) shall
certify to the Trustee that contemporaneously with such purchase, such
purchaser(s) is purchasing, pursuant to the terms of this Agreement and the
Other Pass Through Trust Agreements, the Class A Certificates, the Class B
Certificates and the Certificates which are senior to the securities held by
such purchaser(s). Each payment of the purchase price of the Certificates
referred to in the first sentence hereof shall be made to an account or accounts
designated by the Trustee and each such purchase shall be subject to the terms
of this Section 6.01(b). Each Certificateholder agrees by its acceptance of its
Certificate that it will, subject to Section 3.04 hereof, upon payment from such
Class D Certificateholder(s), of the purchase price set forth in the first
sentence of this paragraph, forthwith sell, assign, transfer and convey to the
purchaser(s) thereof (without recourse, representation or warranty of any kind
except for its own acts), all of the right, title, interest and obligation of
such Certificateholder in this Agreement, the Escrow Agreement, the Deposit
Agreement, the Intercreditor Agreement, the Liquidity Facility, the Financing
Documents and all Certificates and Escrow Receipts held by such
Certificateholder (excluding 
<PAGE>   39
                                      -34-


all right, title and interest under any of the foregoing to the extent such
right, title or interest is with respect to an obligation not then due and
payable as respects any action or inaction or state of affairs occurring prior
to such sale) and the purchaser shall assume all of such Certificateholder's
obligations under this Agreement, the Escrow Agreement, the Deposit Agreement,
the Intercreditor Agreement, the Liquidity Facility, the Financing Documents and
all such Certificates and Escrow Receipts. The Certificates will be deemed to be
purchased on the date payment of the purchase price is made notwithstanding the
failure of the Certificateholders to deliver any Certificates (whether in the
form of Definitive Certificates or beneficial interests in Global Certificates)
and, upon such a purchase, (i) the only rights of the Certificateholders will be
to deliver the Certificates to the purchaser(s) and receive the purchase price
for such Certificates and (ii) if the purchaser(s) shall so request, such
Certificateholder will comply with all the provisions of Section 3.04 hereof to
enable new Certificates to be issued to the purchaser in such denominations as
it shall request. All charges and expenses in connection with the issuance of
any such new Certificates shall be borne by the purchaser thereof.

            As used in this Section 6.01(b), the terms "Class A Certificate",
"Class A Certificateholder", "Class A Trust", "Class A Trust Agreement", "Class
A Trustee", "Class B Certificate", "Class B Certificateholder", "Class B Trust",
"Class B Trust Agreement", "Class B Trustee", "Class D Certificate", and "Class
D Trust", shall have the respective meanings assigned to such terms in the
Intercreditor Agreement.

            Section 6.02. Incidents of Sale of Equipment Notes. Upon any sale of
all or any part of the Equipment Notes made either under the power of sale given
under this Agreement or otherwise for the enforcement of this Agreement, the
following shall be applicable:

            (1) Certificateholders and Trustee May Purchase Equipment Notes. Any
      Certificateholder, the Trustee in its individual or any other capacity or
      any other Person may bid for and purchase any of the Equipment Notes, and
      upon compliance with the terms of sale, may hold, retain, possess and
      dispose of such Equipment Notes in their own absolute right without
      further accountability.

            (2) Receipt of Trustee Shall Discharge Purchaser. The receipt of the
      Trustee making such sale shall be a sufficient discharge to any purchaser
      for his purchase money, and, after paying such purchase money and
      receiving such receipt, such purchaser or its personal representative or
      assigns shall not be obliged to see to the application of such purchase
      money, or be in any way answerable for any loss, misapplication or
      non-application thereof.

            (3) Application of Moneys Received upon Sale. Any moneys collected
      by the Trustee upon any sale made either under the power of sale given by
      this Agreement or otherwise for the enforcement of this Agreement shall be
      applied as provided in Section 4.02.

            Section 6.03. Judicial Proceedings Instituted by Trustee; Trustee
May Bring Suit. If there shall be a failure to make payment of the principal of,
premium, if any, or interest on any Equipment Note, or if there shall be any
failure to pay Rent (as defined in the relevant Lease) under any Lease when due
and payable, then the Trustee, in its own name and as trustee 
<PAGE>   40
                                      -35-


of an express trust, as holder of such Equipment Notes, to the extent permitted
by and in accordance with the terms of the Intercreditor Agreement and the
Financing Documents (subject to the rights of the applicable Owner Trustee or
Owner Participant to cure any such failure to pay principal of, premium, if any,
or interest on any Equipment Note or to pay Rent under any Lease in accordance
with the applicable Indenture), shall be entitled and empowered to institute any
suits, actions or proceedings at law, in equity or otherwise, for the collection
of the sums so due and unpaid on such Equipment Notes or under such Lease and
may prosecute any such claim or proceeding to judgment or final decree with
respect to the whole amount of any such sums so due and unpaid.

            Section 6.04. Control by Certificateholders. Subject to Section 6.03
and the Intercreditor Agreement, the Certificateholders holding Certificates
evidencing Fractional Undivided Interests aggregating not less than a majority
in interest in the Trust shall have the right to direct the time, method and
place of conducting any proceeding for any remedy available to the Trustee with
respect to the Trust or pursuant to the terms of the Intercreditor Agreement, or
exercising any trust or power conferred on the Trustee under this Agreement or
the Intercreditor Agreement, including any right of the Trustee as Controlling
Party under the Intercreditor Agreement or as holder of the Equipment Notes,
provided that:

            (1) such Direction shall not be in conflict with any rule of law or
      with this Agreement and would not involve the Trustee in personal
      liability or expense,

            (2) the Trustee shall not determine that the action so directed
      would be unjustly prejudicial to the Certificateholders not taking part in
      such Direction, and

            (3) the Trustee may take any other action deemed proper by the
      Trustee which is not inconsistent with such Direction.

            Section 6.05. Waiver of Past Defaults. Subject to the Intercreditor
Agreement, the Certificateholders holding Certificates evidencing Fractional
Undivided Interests aggregating not less than a majority in interest in the
Trust (i) may on behalf of all of the Certificateholders waive any past Event of
Default hereunder and its consequences or (ii) if the Trustee is the Controlling
Party, may direct the Trustee to instruct the applicable Loan Trustee to waive
any past Indenture Default under any Indenture and its consequences, and thereby
annul any Direction given by such Certificateholders or the Trustee to such Loan
Trustee with respect thereto, except a default:

            (1) in the deposit of any Scheduled Payment or Special Payment under
      Section 4.01 or in the distribution of any payment under Section 4.02 on
      the Certificates, or

            (2) in the payment of the principal of (premium, if any) or interest
      on the Equipment Notes, or

            (3) in respect of a covenant or provision hereof which under Article
      IX cannot be modified or amended without the consent of each
      Certificateholder holding an Outstanding Certificate affected thereby.
<PAGE>   41
                                      -36-


            Upon any such waiver, such default shall cease to exist with respect
to the Certificates and any Event of Default arising therefrom shall be deemed
to have been cured for every purpose and any direction given by the Trustee on
behalf of the Certificateholders to the relevant Loan Trustee shall be annulled
with respect thereto; but no such waiver shall extend to any subsequent or other
default or Event of Default or impair any right consequent thereon. Upon any
such waiver, the Trustee shall vote the Equipment Notes issued under the
relevant Indenture to waive the corresponding Indenture Default.

            Section 6.06. Right of Certificateholders to Receive Payments Not to
Be Impaired. Anything in this Agreement to the contrary notwithstanding,
including, without limitation, Section 6.07 hereof, but subject to the
Intercreditor Agreement, the right of any Certificateholder to receive
distributions of payments required pursuant to Section 4.02 hereof on the
Certificates when due, or to institute suit for the enforcement of any such
payment on or after the applicable Regular Distribution Date or Special
Distribution Date, shall not be impaired or affected without the consent of such
Certificateholder.

            Section 6.07. Certificateholders May Not Bring Suit Except Under
Certain Conditions. A Certificateholder shall not have the right to institute
any suit, action or proceeding at law or in equity or otherwise with respect to
this Agreement, for the appointment of a receiver or for the enforcement of any
other remedy under this Agreement, unless:

            (1) such Certificateholder previously shall have given written
      notice to the Trustee of a continuing Event of Default;

            (2) Certificateholders holding Certificates evidencing Fractional
      Undivided Interests aggregating not less than 25% of the Trust shall have
      requested the Trustee in writing to institute such action, suit or
      proceeding and shall have offered to the Trustee indemnity as provided in
      Section 7.03(e);

            (3) the Trustee shall have refused or neglected to institute such an
      action, suit or proceeding for 60 days after receipt of such notice,
      request and offer of indemnity; and

            (4) no direction inconsistent with such written request shall have
      been given to the Trustee during such 60-day period by Certificateholders
      holding Certificates evidencing Fractional Undivided Interests aggregating
      not less than a majority in interest in the Trust.

            It is understood and intended that no one or more of the
Certificateholders shall have any right in any manner whatsoever hereunder or
under the Certificates to (i) surrender, impair, waive, affect, disturb or
prejudice any property in the Trust Property or the lien of any Indenture on any
property subject thereto, or the rights of the Certificateholders or the holders
of the Equipment Notes, (ii) obtain or seek to obtain priority over or
preference with respect to any other such Certificateholder or (iii) enforce any
right under this Agreement, except in the manner herein provided and for the
equal, ratable and common benefit of all the Certificateholders subject to the
provisions of this Agreement.

            Section 6.08. Remedies Cumulative. Every remedy given hereunder to
the Trustee or to any of the Certificateholders shall not be exclusive of any
other remedy or 
<PAGE>   42
                                      -37-


remedies, and every such remedy shall be cumulative and in addition to every
other remedy given hereunder or now or hereafter given by statute, law, equity
or otherwise.


                                   ARTICLE VII

                                   THE TRUSTEE

            Section 7.01. Certain Duties and Responsibilities. (a) Except during
the continuance of an Event of Default, the Trustee undertakes to perform such
duties as are specifically set forth in this Agreement, and no implied covenants
or obligations shall be read into this Agreement against the Trustee.

            (b) In case an Event of Default has occurred and is continuing, the
Trustee shall exercise such of the rights and powers vested in it by this
Agreement, and use the same degree of care and skill in their exercise, as a
prudent man would exercise or use under the circumstances in the conduct of its
own affairs.

            (c) No provision of this Agreement shall be construed to relieve the
Trustee from liability for its own negligent action, its own negligent failure
to act, or its own wilful misconduct, except that

            (1) this Subsection shall not be construed to limit the effect of
      Subsection (a) of this Section; and

            (2) the Trustee shall not be liable for any error of judgment made
      in good faith by a Responsible Officer of the Trustee, unless it shall be
      proved that the Trustee was negligent in ascertaining the pertinent facts.

            (d) Whether or not herein expressly so provided, every provision of
this Trust Agreement relating to the conduct or affecting the liability of or
affording protection to the Trustee shall be subject to the provisions of this
Section.

            Section 7.02. Notice of Defaults. As promptly as practicable after,
and in any event within 90 days after, the occurrence of any default (as such
term is defined below) hereunder, the Trustee shall transmit by mail to the
Company, the Owner Trustees, the Owner Participants, the Loan Trustees and the
Certificateholders in accordance with Section 313(c) of the Trust Indenture Act,
notice of such default hereunder known to the Trustee, unless such default shall
have been cured or waived; provided, however, that, except in the case of a
default on the payment of the principal, premium, if any, or interest on any
Equipment Note held in the Trust, the Trustee shall be protected in withholding
such notice if and so long as the board of directors, the executive committee or
a trust committee of directors and/or Responsible Officers of the Trustee in
good faith determine that the withholding of such notice is in the interests of
the Certificateholders. For the purpose of this Section, the term "default"
means any event that is, or after notice or lapse of time or both would become,
an Event of Default.

            Section 7.03. Certain Rights of Trustee. Subject to the provisions
of Section 315 of the Trust Indenture Act:
<PAGE>   43
                                      -38-


            (a) the Trustee may rely and shall be protected in acting or
      refraining from acting in reliance upon any resolution, certificate,
      statement, instrument, opinion, report, notice, request, direction,
      consent, order, bond, debenture or other paper or document believed by it
      to be genuine and to have been signed or presented by the proper party or
      parties;

            (b) any request or direction of the Company mentioned herein shall
      be sufficiently evidenced by a written description of the subject matter
      thereof accompanied by an Officer's Certificate and an Opinion of Counsel
      as provided in Section 1.02 of this Agreement;

            (c) whenever in the administration of this Agreement the Trustee
      shall deem it desirable that a matter be proved or established prior to
      taking, suffering or omitting any action hereunder, the Trustee (unless
      other evidence be herein specifically prescribed) may, in the absence of
      bad faith on its part, rely upon an Officer's Certificate of the Company,
      any Owner Trustee or any Loan Trustee;

            (d) the Trustee may consult with counsel and the advice of such
      counsel or any Opinion of Counsel shall be full and complete authorization
      and protection in respect of any action taken, suffered or omitted by it
      hereunder in good faith and in reliance thereon;

            (e) the Trustee shall be under no obligation to exercise any of the
      rights or powers vested in it by this Agreement at the Direction of any of
      the Certificateholders pursuant to this Agreement, unless such
      Certificateholders shall have offered to the Trustee reasonable security
      or indemnity against the cost, expenses and liabilities which might be
      incurred by it in compliance with such Direction;

            (f) the Trustee shall not be bound to make any investigation into
      the facts or matters stated in any resolution, certificate, statement,
      instrument, opinion, report, notice, request, direction, consent, order,
      bond, debenture or other paper or document;

            (g) the Trustee may execute any of the trusts or powers under this
      Agreement or perform any duties under this Agreement either directly or by
      or through agents or attorneys, and the Trustee shall not be responsible
      for any misconduct or negligence on the part of any agent or attorney
      appointed with due care by it under this Agreement;

            (h) the Trustee shall not be liable with respect to any action taken
      or omitted to be taken by it in good faith in accordance with the
      Direction of the Certificateholders holding Certificates evidencing
      Fractional Undivided Interests aggregating not less than a majority in
      interest in the Trust relating to the time, method and place of conducting
      any proceeding for any remedy available to the Trustee, or exercising any
      trust or power conferred upon the Trustee, under this Agreement; and

            (i) the Trustee shall not be required to expend or risk its own
      funds in the performance of any of its duties under this Agreement, or in
      the exercise of any of its rights or powers, if it shall have reasonable
      grounds for believing that repayment of such funds or adequate indemnity
      against such risk is not reasonably assured to it.
<PAGE>   44
                                      -39-


            Section 7.04. Not Responsible for Recitals or Issuance of
Certificates. The recitals contained herein and in the Certificates, except the
certificates of authentication, shall not be taken as the statements of the
Trustee, and the Trustee assumes no responsibility for their correctness.
Subject to Section 7.15, the Trustee makes no representations as to the validity
or sufficiency of this Agreement, any Equipment Notes, the Intercreditor
Agreement, the Deposit Agreement, the Escrow Agreement, the Certificates or any
other Financing Document, except that the Trustee hereby represents and warrants
that this Agreement has been, and the Intercreditor Agreement, the Registration
Rights Agreement, the Note Purchase Agreement, the Escrow Agreement and each
Certificate will be, executed, authenticated and delivered by one of its
officers who is duly authorized to execute, authenticate and deliver such
document on its behalf.

            Section 7.05. May Hold Certificates. The Trustee, any Paying Agent,
Registrar or any of their Affiliates or any other agent in their respective
individual or any other capacity may become the owner or pledgee of Certificates
and, subject to Sections 310(b) and 311 of the Trust Indenture Act, if
applicable, may otherwise deal with the Company, the Owner Trustees or the Loan
Trustees with the same rights it would have if it were not Trustee, Paying
Agent, Registrar or such other agent.

            Section 7.06. Money Held in Trust. Money held by the Trustee or the
Paying Agent in trust hereunder need not be segregated from other funds except
to the extent required herein or by law and neither the Trustee nor the Paying
Agent shall have any liability for interest upon any such moneys except as
provided for herein.

            Section 7.07. Compensation and Reimbursement. The Company agrees:

            (1) to pay, or cause to be paid, to the Trustee from time to time
      reasonable compensation for all services rendered by it hereunder as set
      forth in a written fee letter dated the date hereof between the Company
      and the Trustee, which letter is incorporated herein by reference (which
      compensation shall not be limited by any provision of law in regard to the
      compensation of a trustee of an express trust);

            (2) except as otherwise expressly provided herein, to reimburse, or
      cause to be reimbursed, the Trustee upon its request for all reasonable
      out-of-pocket expenses, disbursements and advances incurred or made by the
      Trustee in accordance with any provision of this Agreement (including the
      reasonable compensation and the expenses and disbursements of its agents
      and counsel), except any such expense, disbursement or advance as may be
      attributable to its undertaking its normal administrative functions, or
      its negligence, willful misconduct or bad faith or as may be incurred due
      to the Trustee's breach of its representations and warranties set forth in
      Section 7.15; and

            (3) to indemnify, or cause to be indemnified, the Trustee for, and
      to hold it harmless against, any loss, liability, expense or Tax (other
      than for or with respect to any Unindemnified Tax) incurred without
      negligence, willful misconduct or bad faith, on its part, arising out of
      or in connection with the acceptance or administration of this Trust,
      including the costs and expenses of defending itself against any claim or
      liability in connection with the exercise or performance of any of its
      powers or duties hereunder, 
<PAGE>   45
                                      -40-


      except for any such loss, liability or expense incurred by reason of the
      Trustee's breach of its covenants hereunder or under any Financing
      Document to which it is a party or its representations and warranties set
      forth in Section 7.15 or in any other Financing Document, the
      authorization or giving or withholding of any future amendments,
      supplements, waivers or consents with respect hereto or any of the
      Financing Documents, which amendments, supplements, waivers or consents
      are not required pursuant to the terms of the Financing Documents and not
      requested by the Company, any loss of tax benefits, any Unindemnified Tax,
      or increase in tax liability under any tax law whether or not the Company
      is required to indemnify thereof or pursuant to this Agreement or any
      costs associated with overhead or normal administration hereunder or any
      voluntary resignation pursuant to Section 7.09.

            With respect to paragraph (3) above, the Trustee shall notify the
Company promptly of any claim for which it may seek indemnity and the Company
shall make payment on any such claim within 30 days of written demand thereof
(delivered together with supporting documentation). The Company shall defend the
claim and the Trustee shall cooperate in the defense. The Trustee may have
separate counsel with the consent of the Company and the Company will pay the
reasonable fees and expenses of such counsel. The Company need not pay for any
settlement made, in settlement or otherwise, without its consent.

            With respect to any Tax other than an Unindemnified Tax, the Trustee
shall be entitled to reimbursement from, and shall have a lien prior to the
Certificates upon, the Trust Property for any such Tax incurred without
negligence, bad faith or willful misconduct, on its part, arising out of or in
connection with the acceptance or administration of such Trust (other than any
Tax attributable to the Trustee's compensation for serving as such), including
any costs and expenses incurred in contesting the imposition of any such Tax. If
the Trustee reimburses itself from the Trust Property of such Trust for any such
Tax, it will mail a brief report within 30 days setting forth the circumstances
thereof to all Certificateholders as their names and addresses appear in the
Register.

            Section 7.08. Corporate Trustee Required; Eligibility. There shall
at all times be a Trustee hereunder which shall be eligible to act as a trustee
under Section 310(a) of the Trust Indenture Act and shall have a combined
capital and surplus of at least $75,000,000 (or a combined capital and surplus
in excess of $5,000,000 and the obligations of which, whether now in existence
or hereafter incurred, are fully and unconditionally guaranteed by a corporation
organized and doing business under the laws of the United States, any state or
territory thereof or of the District of Columbia and having a combined capital
and surplus of at least $75,000,000). If such corporation publishes reports of
conditions at least annually, pursuant to law or to the requirements of federal,
state, territorial or District of Columbia supervising or examining authority,
then for the purposes of this Section 7.08, the combined capital and surplus of
such corporation shall be deemed to be its combined capital and surplus as set
forth in its most recent report of conditions so published.

            In case at any time the Trustee shall cease to be eligible in
accordance with the provisions of this Section 7.08 to act as Trustee, the
Trustee shall resign immediately as Trustee in the manner and with the effect
specified in Section 7.09.
<PAGE>   46
                                      -41-


            Section 7.09. Resignation and Removal; Appointment of Successor. (a)
No resignation or removal of the Trustee and no appointment of a successor
Trustee pursuant to this Article shall become effective until the acceptance of
appointment by the successor Trustee under Section 7.10.

            (b) The Trustee may resign at any time as trustee by giving prior
written notice thereof to the Company, the Authorized Agents, the Owner Trustees
and the Loan Trustees. If an instrument of acceptance by a successor Trustee
shall not have been delivered to the Company, the Authorized Agents, the Owner
Trustees, the Loan Trustees and the Trustee within 30 days after the giving of
such notice of resignation, the resigning Trustee may petition any court of
competent jurisdiction for the appointment of a successor Trustee.

            (c) The Trustee may be removed at any time by Direction of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not less than a majority in interest in the Trust
delivered to the Trustee and to the Company, the Owner Trustees and the Loan
Trustees.

            (d) If at any time:

            (1) the Trustee shall fail to comply with Section 310 of the Trust
      Indenture Act, if applicable, after written request therefor by the
      Company or by any Certificateholder who has been a bona fide
      Certificateholder for at least six months; or

            (2) the Trustee shall cease to be eligible under Section 7.08 and
      shall fail to resign after written request therefor by the Company or by
      any such Certificateholder; or

            (3) the Trustee shall become incapable of acting or shall be
      adjudged a bankrupt or insolvent or a receiver of the Trustee or of its
      property shall be appointed or any public officer shall take charge or
      control of the Trustee or of its property or affairs for the purpose of
      rehabilitation, conservation or liquidation;

then, in any case, (i) the Company may remove the Trustee or (ii) any
Certificateholder who has been a bona fide Certificateholder for at least six
months may, on behalf of itself and all others similarly situated, petition any
court of competent jurisdiction for the removal of the Trustee and the
appointment of a successor Trustee.

            (e) If a Responsible Officer of the Trustee shall obtain actual
knowledge of an Avoidable Tax which has been or is likely to be asserted, the
Trustee shall promptly notify the Company and shall, within 30 days of such
notification, resign hereunder unless within such 30-day period the Trustee
shall have received notice that the Company has agreed to pay such tax. The
Company shall promptly appoint a successor Trustee in a jurisdiction where there
are no Avoidable Taxes.

            (f) If the Trustee shall resign, be removed or become incapable of
acting or if a vacancy shall occur in the office of the Trustee for any cause,
the Company shall promptly appoint a successor Trustee. If, within one year
after such resignation, removal or incapability, or other occurrence of such
vacancy, a successor Trustee shall be appointed by Direction of the
Certificateholders holding Certificates evidencing Fractional Undivided
Interests aggregating not 
<PAGE>   47
                                      -42-


less than a majority in interest in the Trust delivered to the Company, the
Owner Trustees, the Loan Trustees and the retiring Trustee, and the Company
approves such appointment, which approval shall not be unreasonably withheld,
then the successor Trustee so appointed shall, forthwith upon its acceptance of
such appointment, become the successor Trustee and supersede the successor
Trustee appointed as provided above. If no successor Trustee shall have been so
appointed as provided above and accepted appointment in the manner hereinafter
provided, any Certificateholder who has been a bona fide Certificateholder for
at least six months may, on behalf of himself and all others similarly situated,
petition any court of competent jurisdiction for the appointment of a successor
Trustee.

            (g) The successor Trustee shall give notice of the resignation and
removal of the Trustee and appointment of the successor Trustee by mailing
written notice of such event by first-class mail, postage prepaid, to the
Certificateholders as their names and addresses appear in the Register. Each
notice shall include the name of such successor Trustee and the address of its
Corporate Trust Office.

            Section 7.10. Acceptance of Appointment by Successor. Every
successor Trustee appointed hereunder shall execute and deliver to the Company,
the Authorized Agents, the Owner Trustees and the Loan Trustees and to the
retiring Trustee an instrument accepting such appointment, and thereupon the
resignation or removal of the retiring Trustee shall become effective and such
successor Trustee, without any further act, deed or conveyance, shall become
vested with all the rights, powers, trusts and duties of the retiring Trustee;
but, on request of the Company or the successor Trustee, such retiring Trustee
shall execute and deliver an instrument transferring to such successor Trustee
all such rights, powers and trusts of the retiring Trustee and shall duly
assign, transfer and deliver to such successor Trustee all Trust Property held
by such retiring Trustee hereunder, subject nevertheless to its lien, if any,
provided for in Section 7.07. Upon request of any such successor Trustee, the
Company, the retiring Trustee and such successor Trustee shall execute and
deliver any and all instruments containing such provisions as shall be necessary
or desirable to transfer and confirm to, and for more fully and certainly
vesting in, such successor Trustee all such rights, powers and trusts.

            No institution shall accept its appointment as a Trustee hereunder
unless at the time of such acceptance such institution shall be qualified and
eligible under this Article VII.

            Section 7.11. Merger, Conversion, Consolidation or Succession to
Business. Any corporation into which the Trustee may be merged or converted or
with which it may be consolidated, or any corporation resulting from any merger,
conversion or consolidation to which the Trustee shall be a party, or any
corporation succeeding to all or substantially all of the corporate trust
business of the Trustee, shall be the successor of the Trustee hereunder,
provided such corporation shall be otherwise qualified and eligible under this
Article VII, without the execution or filing of any paper or any further act on
the part of any of the parties hereto. In case any Certificates shall have been
executed or authenticated, but not delivered, by the Trustee then in office, any
successor by merger, conversion or consolidation to such authenticating Trustee
may adopt such execution or authentication and deliver the Certificates so
executed or authenticated with the same effect as if such successor Trustee had
itself executed or authenticated such Certificates.
<PAGE>   48
                                      -43-


            Section 7.12. Maintenance of Agencies. (a) There shall at all times
be maintained an office or agency in the location set forth in Section 12.03
where Certificates may be presented or surrendered for registration of transfer
or for exchange, and for payment thereof and where notices and demands to or
upon the Trustee in respect of such certificates or this Agreement may be
served; provided, however, that, if it shall be necessary that the Trustee
maintain an office or agency in another location (e.g., the Certificates shall
be represented by Definitive Certificates and shall be listed on a national
securities exchange), the Trustee will make all reasonable efforts to establish
such an office or agency. Written notice of the location of each such other
office or agency and of any change of location thereof shall be given by the
Trustee to the Company, the Owner Trustees, the Loan Trustees (in the case of
any Owner Trustee or Loan Trustee, at its address specified in the Financing
Documents or such other address as may be notified to the Trustee) and the
Certificateholders. In the event that no such office or agency shall be
maintained or no such notice of location or of change of location shall be
given, presentations and demands may be made and notices may be served at the
Corporate Trust Office of the Trustee.

            (b) There shall at all times be a Registrar and a Paying Agent
hereunder with respect to the Certificates. Each such Authorized Agent shall be
a bank or trust company, shall be a corporation organized and doing business
under the laws of the United States or any state, with a combined capital and
surplus of at least $75,000,000, or, if the Trustee shall be acting as the
Registrar or Paying Agent hereunder, a corporation having a combined capital and
surplus in excess of $5,000,000, the obligations of which are guaranteed by a
corporation organized and doing business under the laws of the United States or
any state, with a combined capital and surplus of at least $75,000,000, and
shall be authorized under such laws to exercise corporate trust powers, subject
to supervision by Federal or state authorities. The Trustee shall initially be
the Paying Agent and, as provided in Section 3.04, Registrar hereunder with
respect to the Certificates. Each Registrar shall furnish to the Trustee, at
stated intervals of not more than six months, and at such other times as the
Trustee may request in writing, a copy of the Register maintained by such
Registrar.

            (c) Any corporation into which any Authorized Agent may be merged or
converted or with which it may be consolidated, or any corporation resulting
from any merger, consolidation or conversion to which any Authorized Agent shall
be a party, or any corporation succeeding to the corporate trust business of any
Authorized Agent, shall be the successor of such Authorized Agent hereunder, if
such successor corporation is otherwise eligible under this Section, without the
execution or filing of any paper or any further act on the part of the parties
hereto or such Authorized Agent or such successor corporation.

            (d) Any Authorized Agent may at any time resign by giving written
notice of resignation to the Trustee, the Company, the Owner Trustees and the
Loan Trustees. The Company may, and at the request of the Trustee shall, at any
time terminate the agency of any Authorized Agent by giving written notice of
termination to such Authorized Agent and to the Trustee. Upon the resignation or
termination of an Authorized Agent or in case at any time any such Authorized
Agent shall cease to be eligible under this Section (when, in either case, no
other Authorized Agent performing the functions of such Authorized Agent shall
have been appointed), the Company shall promptly appoint one or more qualified
successor Authorized Agents, reasonably satisfactory to the Trustee, to perform
the functions of the Authorized Agent 
<PAGE>   49
                                      -44-


which has resigned or whose agency has been terminated or who shall have ceased
to be eligible under this Section. The Company shall give written notice of any
such appointment made by it to the Trustee, the Owner Trustees and the Loan
Trustees; and in each case the Trustee shall mail notice of such appointment to
all Certificateholders as their names and addresses appear on the Register.

            (e) The Company agrees to pay, or cause to be paid, from time to
time to each Authorized Agent reasonable compensation for its services and to
reimburse it for its reasonable expenses as set forth in the letter agreement
referred to in Section 7.07 hereof.

            Section 7.13. Money for Certificate Payments to Be Held in Trust.
All moneys deposited with any Paying Agent for the purpose of any payment on
Certificates shall be deposited and held in trust for the benefit of the
Certificateholders entitled to such payment, subject to the provisions of this
Section. Moneys so deposited and held in trust shall constitute a separate trust
fund for the benefit of the Certificateholders with respect to which such money
was deposited.

            The Trustee may at any time, for the purpose of obtaining the
satisfaction and discharge of this Agreement or for any other purpose, direct
any Paying Agent to pay to the Trustee all sums held in trust by such Paying
Agent, such sums to be held by the Trustee upon the same trusts as those upon
which such sums were held by such Paying Agent; and, upon such payment by any
Paying Agent to the Trustee, such Paying Agent shall be released from all
further liability with respect to such money.

            Section 7.14. Registration of Equipment Notes in Name of
Subordination Agent. The Trustee agrees that all Equipment Notes to be purchased
by the Trust shall be issued in the name of the Subordination Agent or its
nominee and held by the Subordination Agent in trust for the benefit of the
Certificateholders, or, if not so held, the Subordination Agent or its nominee
shall be reflected as the owner of such Equipment Notes in the register of the
issuer of such Equipment Notes.

            Section 7.15. Representations and Warranties of Trustee. The Trustee
hereby represents and warrants on the Transfer Date that:

            (a) the Trustee is a Delaware banking corporation organized and
      validly existing in good standing under the laws of the State of Delaware;

            (b) the Trustee has full power, authority and legal right to receive
      the Trust Property assigned by the Related Trustee, assume the obligations
      under, and perform, the Assignment and Assumption Agreement, this
      Agreement, the Intercreditor Agreement, the Registration Rights Agreement,
      the Escrow Agreement, the Note Purchase Agreement and the Financing
      Documents to which it is a party and has taken all necessary action to
      authorize such receipt, assumption and performance by it of the Assignment
      and Assumption Agreement, this Agreement, the Intercreditor Agreement, the
      Registration Rights Agreement, the Escrow Agreement, the Note Purchase
      Agreement and the Financing Documents to which it is a party;
<PAGE>   50
                                      -45-


            (c) the receipt of the Trust Property under the Assignment and
      Assumption Agreement and the performance by the Trustee of the Assignment
      and Assumption Agreement, this Agreement, the Intercreditor Agreement, the
      Registration Rights Agreement, the Escrow Agreement, the Note Purchase
      Agreement and the Financing Documents to which it is a party (i) will not
      violate any provision of United States federal law or the law of the state
      of the United States where it is located governing the banking and trust
      powers of the Trustee or any order, writ, judgment, or decree of any
      court, arbitrator or governmental authority applicable to the Trustee or
      any of its assets, (ii) will not violate any provision of the articles of
      association or by-laws of the Trustee, or (iii) will not violate any
      provision of, or constitute, with or without notice or lapse of time, a
      default under, or result in the creation or imposition of any lien on any
      properties included in the Trust Property pursuant to the provisions of
      any mortgage, indenture, contract, agreement or other undertaking to which
      it is a party, which violation, default or lien could reasonably be
      expected to have an adverse effect on the Trustee's performance or ability
      to perform its duties hereunder or thereunder or on the transactions
      contemplated herein or therein;

            (d) the receipt of the Trust Property under the Assignment and
      Assumption Agreement and the performance by the Trustee of the Assignment
      and Assumption Agreement, this Agreement, the Intercreditor Agreement, the
      Registration Rights Agreement, the Escrow Agreement, the Note Purchase
      Agreement, and the Financing Documents to which it is a party will not
      require the authorization, consent, or approval of, the giving of notice
      to, the filing or registration with, or the taking of any other action in
      respect of, any governmental authority or agency of the United States or
      the state of the United States where it is located regulating the banking
      and corporate trust activities of the Trustee; and

            (e) the Assignment and Assumption Agreement has been duly executed
      and delivered by the Trustee and this Agreement, the Assignment and
      Assumption Agreement, the Intercreditor Agreement, the Registration Rights
      Agreement, the Escrow Agreement, the Note Purchase Agreement, and the
      Financing Documents to which it is a party constitute the legal, valid,
      and binding agreements of the Trustee, enforceable against it in
      accordance with their respective terms, provided that enforceability may
      be limited by (i) applicable bankruptcy, insolvency, reorganization,
      moratorium or similar laws affecting the rights of creditors generally and
      (ii) general principles of equity, regardless of whether applied in a
      proceeding in equity or at law.

            Section 7.16. Withholding Taxes, Information Reporting. The Trustee,
as trustee of the grantor trust created by this Agreement, shall exclude and
withhold from each distribution of principal, premium, if any, and interest and
other amounts due under this Agreement or under the Certificates any and all
withholding taxes applicable thereto as required by law. The Trustee agrees to
act as such withholding agent and, in connection therewith, whenever any present
or future taxes or similar charges are required to be withheld with respect to
any amounts payable in respect of the Certificates, to withhold such amounts and
timely pay the same to the appropriate authority in the name of and on behalf of
the Certificateholders, that it will file any necessary withholding tax returns
or statements when due, and that, as promptly as possible after the payment
thereof, it will deliver to each such Certificateholder appropriate
<PAGE>   51
                                      -46-


documentation showing the payment thereof, together with such additional
documentary evidence as such Certificateholders may reasonably request from time
to time. The Trustee agrees to file any other information reports as it may be
required to file under United States law. Each Certificateholder or Investor
that is not a United States person within the meaning of section 7701(a)(30) of
the Internal Revenue Code, as amended, by its acceptance of a Certificate or a
beneficial interest therein, agrees to indemnify and hold harmless the Trust and
the Trustee from and against any improper failure to withhold taxes from amounts
payable to it or for its benefit, other than an improper failure attributable to
the gross negligence or willful misconduct of the Trustee.

            Section 7.17. Trustee's Liens. The Trustee in its individual
capacity agrees that it will at its own cost and expense promptly take any
action as may be necessary to duly discharge and satisfy in full any mortgage,
pledge, lien, charge, encumbrance, security interest or claim ("Trustee's
Liens") on or with respect to the Trust Property which is attributable to the
Trustee either (i) in its individual capacity and which is unrelated to the
transactions contemplated by this Agreement, the Intercreditor Agreement, the
Note Purchase Agreement or the Financing Documents, or (ii) as Trustee hereunder
or in its individual capacity and which arises out of acts or omissions on the
part of the Trustee which are not contemplated by this Agreement.

            Section 7.18. Preferential Collection of Claims. The Trustee shall
comply with Section 311(a) of the Trust Indenture Act, excluding any creditor
relationship listed in Section 311(b) of the Trust Indenture Act. If the Trustee
shall resign or be removed as Trustee, it shall be subject to Section 311(a) of
the Trust Indenture Act to the extent provided therein.


                                  ARTICLE VIII

                CERTIFICATEHOLDERS' LISTS AND REPORTS BY TRUSTEE

            Section 8.01. The Company to Furnish Trustee with Names and
Addresses of Certificateholders. The Company will furnish to the Trustee within
15 days after each Record Date with respect to a Scheduled Payment, and at such
other times as the Trustee may request in writing within 30 days after receipt
by the Company of any such request, a list, in such form as the Trustee may
reasonably require, of all information in the possession or control of the
Company as to the names and addresses of the Certificateholders, in each case as
of a date not more than 15 days prior to the time such list is furnished;
provided, however, that so long as the Trustee is the sole Registrar, no such
list need be furnished; and provided further, however, that no such list need be
furnished for so long as a copy of the Register is being furnished to the
Trustee pursuant to Section 7.12.

            Section 8.02. Preservation of Information; Communications to
Certificateholders. The Trustee shall preserve, in as current a form as is
reasonably practicable, the names and addresses of Certificateholders contained
in the most recent list furnished to the Trustee as provided in Section 7.12 or
Section 8.01, as the case may be, and the names and addresses of
Certificateholders received by the Trustee in its capacity as Registrar, if so
acting. The Trustee may destroy any list furnished to it as provided in Section
7.12 or Section 8.01, as the case may be, upon receipt of a new list so
furnished.
<PAGE>   52
                                      -47-


            Section 8.03. Reports by Trustee. Within 60 days after May 15 of
each year commencing with the first full year following the date hereof, the
Trustee shall transmit to the Certificateholders, as provided in Section 313(c)
of the Trust Indenture Act, a brief report dated as of such May 15, if required
by Section 313(a) of the Trust Indenture Act.

            Section 8.04. Reports by the Company. The Company shall:

            (a) file with the Trustee, within 30 days after the Company is
      required to file the same with the SEC, copies of the annual reports and
      of the information, documents and other reports (or copies of such
      portions of any of the foregoing as the SEC may from time to time by rules
      and regulations prescribe) which the Company is required to file with the
      SEC pursuant to section 13 or section 15(d) of the Securities Exchange Act
      of 1934, as amended; or, if the Company is not required to file
      information, documents or reports pursuant to either of such sections,
      then to file with the Trustee and the SEC, in accordance with rules and
      regulations prescribed by the SEC, such of the supplementary and periodic
      information, documents and reports which may be required pursuant to
      section 13 of the Securities Exchange Act of 1934, as amended, in respect
      of a security listed and registered on a national securities exchange as
      may be prescribed in such rules and regulations;

            (b) during any period, prior to the consummation of the Exchange
      Offer and during which the Shelf Registration Statement is not in effect,
      in which the Company is not subject to Section 13(a), 13(c) or 15(d) under
      the Securities Exchange Act of 1934, make available to any Holder of the
      Certificates in connection with any sale thereof and any prospective
      purchaser of the Certificates from such Holder, in each case upon request,
      the information specified in, and meeting the requirements of, Rule
      144A(d)(4) under the Securities Act but only for so long as any of the
      Certificates remain outstanding and are "restricted securities" within the
      meaning of Rule 144(a)(3) under the Securities Act and, in any event, only
      until the second anniversary of the Issuance Date;

            (c) file with the Trustee and the SEC, in accordance with the rules
      and regulations prescribed by the SEC, such additional information,
      documents and reports with respect to compliance by the Company with the
      conditions and covenants provided for in this Agreement, as may be
      required by such rules and regulations, including, in the case of annual
      reports, if required by such rules and regulations, certificates or
      opinions of independent public accountants, conforming to the requirements
      of Section 1.02;

            (d) transmit to all Certificateholders, in the manner and to the
      extent provided in Section 313(c) of the Trust Indenture Act such
      summaries of any information, documents and reports required to be filed
      by the Company pursuant to subsections (a) and (c) of this Section 8.04 as
      may be required by rules and regulations prescribed by the SEC; and

            (e) furnish to the Trustee, not less often than annually, a brief
      certificate from the principal executive officer, principal financial
      officer, any Vice President (or more senior ranking officer) or the
      principal accounting officer as to his or her knowledge of the Company's
      compliance with all conditions and covenants under this Agreement (it
<PAGE>   53
                                      -48-


      being understood that for purposes of this paragraph (e), such compliance
      shall be determined without regard to any period of grace or requirement
      of notice provided under this Agreement).


                                   ARTICLE IX

                             SUPPLEMENTAL AGREEMENTS

            Section 9.01. Supplemental Agreements Without Consent of
Certificateholders. Without the consent of the Certificateholders, the Company
may (but will not be required to), and the Trustee (subject to Section 9.03)
shall, at the Company's request, at any time and from time to time, enter into
one or more agreements supplemental hereto or, if applicable, to the
Intercreditor Agreement, the Escrow Agreement, the Note Purchase Agreement, the
Deposit Agreement, the Registration Rights Agreement or any Liquidity Facility
in form satisfactory to the Trustee, for any of the following purposes:

            (1) to evidence the succession of another corporation to the Company
      and the assumption by any such successor of the covenants of the Company
      herein contained or of the Company's obligations under the Note Purchase
      Agreement, the Registration Rights Agreement or any Liquidity Facility; or

            (2) to add to the covenants of the Company for the benefit of the
      Certificateholders, or to surrender any right or power conferred upon the
      Company in this Agreement, the Note Purchase Agreement, the Registration
      Rights Agreement or any Liquidity Facility; or

            (3) to correct or supplement any provision in this Agreement, the
      Intercreditor Agreement, the Escrow Agreement, the Deposit Agreement, the
      Note Purchase Agreement, the Registration Rights Agreement or any
      Liquidity Facility which may be defective or inconsistent with any other
      provision herein or therein or to cure any ambiguity or correct any
      mistake or to modify any other provision with respect to matters or
      questions arising under this Agreement, the Escrow Agreement, the Deposit
      Agreement, the Note Purchase Agreement, the Intercreditor Agreement, the
      Registration Rights Agreement or any Liquidity Facility, provided that any
      such action shall not materially adversely affect the interests of the
      Certificateholders; or

            (4) to comply with any requirement of the SEC, any applicable law,
      rules or regulations of any exchange or quotation system on which the
      Certificates are listed, any regulatory body or the Registration Rights
      Agreement to effectuate the Exchange Offer; or

            (5) to modify, eliminate or add to the provisions of this Agreement
      to such extent as shall be necessary to continue the qualification of this
      Agreement (including any supplemental agreement) under the Trust Indenture
      Act or under any similar Federal statute hereafter enacted, and to add to
      this Agreement such other provisions as may be expressly permitted by the
      Trust Indenture Act, excluding, however, the provisions referred to in
      Section 316(a)(2) of the Trust Indenture Act as in effect at the date as
      of 
<PAGE>   54
                                      -49-


      which this instrument was executed or any corresponding provision in any
      similar Federal statute hereafter enacted; or

            (6) to evidence and provide for the acceptance of appointment under
      this Agreement by the Trustee of a successor Trustee and to add to or
      change any of the provisions of this Agreement as shall be necessary to
      provide for or facilitate the administration of the Trust, pursuant to the
      requirements of Section 7.10; or

            (7) to provide the information required under Section 7.12 and
      Section 12.03 as to the Trustee; or

            (8) to modify or eliminate provisions relating to the transfer or
      exchange of Exchange Certificates or the Initial Certificates upon
      consummation of the Exchange Offer (as defined in the Registration Rights
      Agreement) or effectiveness of the Shelf Registration Statement or the
      Exchange Offer Registration Statement;

provided, however, that no such supplemental agreement shall adversely affect
the status of any Trust as a grantor trust under Subpart E, Part I of Subchapter
J of Chapter 1 of Subtitle A of the Internal Revenue Code of 1986, as amended,
for U.S. federal income tax purposes.

            Section 9.02. Supplemental Agreements with Consent of
Certificateholders. With the consent of the Certificateholders holding
Certificates (including consents obtained in connection with a tender offer or
exchange offer for the Certificates) evidencing Fractional Undivided Interests
aggregating not less than a majority in interest in the Trust, by Direction of
said Certificateholders delivered to the Company and the Trustee, the Company
may (with the consent of the Owner Trustees, if any, which consent shall not be
unreasonably withheld), and the Trustee (subject to Section 9.03) shall, enter
into an agreement or agreements for the purpose of adding any provisions to or
changing in any manner or eliminating any of the provisions of this Agreement,
the Intercreditor Agreement, any Liquidity Facility, the Registration Rights
Agreement, the Escrow Agreement, the Deposit Agreement or the Note Purchase
Agreement to the extent applicable to such Certificateholders or of modifying in
any manner the rights and obligations of such Certificateholders under this
Agreement, the Intercreditor Agreement, any Liquidity Facility, the Registration
Rights Agreement, the Escrow Agreement, the Deposit Agreement or the Note
Purchase Agreement; provided, however, that no such agreement shall, without the
consent of the Certificateholder of each Outstanding Certificate affected
thereby:

            (1) reduce in any manner the amount of, or delay the timing of, any
      receipt by the Trustee (or, with respect to the Deposits, the
      Certificateholders) of payments on the Equipment Notes held in the Trust
      or on the Deposits or distributions that are required to be made herein on
      any Certificate, or change any date of payment on any Certificate, or
      change the place of payment where, or the coin or currency in which, any
      Certificate is payable, or impair the right to institute suit for the
      enforcement of any such payment or distribution on or after the Regular
      Distribution Date or Special Distribution Date applicable thereto; or
<PAGE>   55
                                      -50-


            (2) permit the disposition of any Equipment Note included in the
      Trust Property except as permitted by this Agreement, or otherwise deprive
      such Certificateholder of the benefit of the ownership of the Equipment
      Notes in the Trust; or

            (3) reduce the specified percentage of the aggregate Fractional
      Undivided Interests of the Trust which is required for any such
      supplemental agreement, or reduce such specified percentage required for
      any waiver of compliance with certain provisions of this Agreement or
      certain defaults hereunder and their consequences provided for in this
      Agreement; or

            (4) waive, amend or modify Section 2.4, 3.2 or 3.3 of the
      Intercreditor Agreement in a manner adverse to the Certificateholders; or

            (5) modify any of the provisions of this Section 9.02 or Section
      6.05, except to increase any such percentage or to provide that certain
      other provisions of this Agreement cannot be modified or waived without
      the consent of the Certificateholder of each Certificate affected thereby;
      or

            (6) adversely affect the status of any Trust as a grantor trust
      under Subpart E, Part I of Subchapter J of Chapter 1 of Subtitle A of the
      Internal Revenue Code of 1986, as amended, for U.S. federal income tax
      purposes.

            It shall not be necessary for any Direction of Certificateholders
under this Section to approve the particular form of any proposed supplemental
agreement, but it shall be sufficient if such Direction shall approve the
substance thereof.

            Section 9.03. Documents Affecting Immunity or Indemnity. If in the
opinion of the Trustee any document required to be executed by it pursuant to
the terms of Section 9.01 or 9.02 affects any interest, right, duty, immunity or
indemnity in favor of the Trustee under this Agreement, the Trustee may in its
discretion decline to execute such document.

            Section 9.04. Execution of Supplemental Agreements. In executing, or
accepting the additional trusts created by, any agreement permitted by this
Article or the modifications thereby of the trusts created by this Agreement,
the Trustee shall be entitled to receive, and shall be fully protected in
relying upon, an Opinion of Counsel stating that the execution of such
supplemental agreement is authorized or permitted by this Agreement.

            Section 9.05. Effect of Supplemental Agreements. Upon the execution
of any agreement supplemental to this Agreement under this Article, this
Agreement shall be modified in accordance therewith, and such supplemental
agreement shall form a part of this Agreement for all purposes; and every Holder
of a Certificate theretofore or thereafter authenticated and delivered hereunder
shall be bound thereby.

            Section 9.06. Conformity with Trust Indenture Act. Every
supplemental agreement executed pursuant to this Article shall conform to the
requirements of the Trust Indenture Act as then in effect.
<PAGE>   56
                                      -51-


            Section 9.07. Reference in Certificates to Supplemental Agreements.
Certificates authenticated and delivered after the execution of any supplemental
agreement pursuant to this Article may bear a notation in form approved by the
Trustee as to any matter provided for in such supplemental agreement; and, in
such case, suitable notation may be made upon Outstanding Certificates after
proper presentation and demand.


                                    ARTICLE X

                AMENDMENTS TO INDENTURES AND FINANCING DOCUMENTS

            Section 10.01. Amendments and Supplements to Indentures and
Financing Documents. In the event that the Trustee, as holder (or beneficial
owner through the Subordination Agent) of any Equipment Note in trust for the
benefit of the Certificateholders or as Controlling Party under the
Intercreditor Agreement, receives (directly or indirectly through the
Subordination Agent) a request for a consent to any amendment, modification,
waiver or supplement under any Indenture, any other Financing Document, any
Equipment Note or any other related document, the Trustee shall forthwith send a
notice of such proposed amendment, modification, waiver or supplement to each
Certificateholder registered on the Register as of the date of such notice. The
Trustee shall request from the Certificateholders a Direction as to (a) whether
or not to take or refrain from taking (or direct the Subordination Agent to take
or refrain from taking) any action which a holder of such Equipment Note has the
option to direct, (b) whether or not to give or execute (or direct the
Subordination Agent to give or execute) any waivers, consents, amendments,
modifications or supplements as a holder of such Equipment Note or a Controlling
Party and (c) how to vote (or direct the Subordination Agent to vote) any
Equipment Note if a vote has been called for with respect thereto. Provided such
a request for Certificateholder Direction shall have been made, in directing any
action or casting any vote or giving any consent as the holder of any Equipment
Note (or in directing the Subordination Agent in any of the foregoing), (i)
other than as Controlling Party, the Trustee shall vote for or give consent to
any such action with respect to such Equipment Note in the same proportion as
that of (A) the aggregate face amounts of all Certificates actually voted in
favor of or for giving consent to such action by such Direction of
Certificateholders to (B) the aggregate face amount of all Outstanding
Certificates and (ii) as Controlling Party, the Trustee shall vote as directed
in such Certificateholder Direction by the Certificateholders evidencing a
Fractional Undivided Interest aggregating not less than a majority in interest
in the Trust. For purposes of the immediately preceding sentence, a Certificate
shall have been "actually voted" if the Holder of such Certificate has delivered
to the Trustee an instrument evidencing such Holder's consent to such Direction
prior to two Business Days before the Trustee directs such action or casts such
vote or gives such consent. Notwithstanding the foregoing, but subject to
Section 6.04 and the Intercreditor Agreement, the Trustee may, in its own
discretion and at its own direction, consent and notify the relevant Loan
Trustee of such consent (or direct the Subordination Agent to consent and notify
the Loan Trustee of such consent) to any amendment, modification, waiver or
supplement under the relevant Indenture, any other Financing Document, any
Equipment Note or any other related document, if an Event of Default hereunder
shall have occurred and be continuing, or if such amendment, modification,
waiver or supplement will not materially adversely affect the interests of the
Certificateholders.
<PAGE>   57
                                      -52-


                                   ARTICLE XI

                              TERMINATION OF TRUST

            Section 11.01. Termination of the Trust. The respective obligations
and responsibilities of the Company and the Trustee with respect to the Trust
shall terminate upon the distribution to all Holders of Certificates and the
Trustee of all amounts required to be distributed to them pursuant to this
Agreement and the disposition of all property held as part of the Trust
Property; provided, however, that in no event shall the Trust continue beyond
one hundred ten (110) years following the date of the earliest execution of this
Trust Agreement.

            Notice of any termination, specifying the Distribution Date upon
which the Certificateholders may surrender their Certificates to the Trustee for
payment of the final Distribution Date and cancellation, shall be mailed
promptly by the Trustee to Certificateholders not earlier than the 60th day and
not later than the 20th day next preceding such final Distribution Date
specifying (A) the Distribution Date upon which the proposed final payment of
the Certificates will be made upon presentation and surrender of Certificates at
the office or agency of the Trustee therein specified, (B) the amount of any
such proposed final payment, and (C) that the Record Date otherwise applicable
to such Distribution Date is not applicable, payments being made only upon
presentation and surrender of the Certificates at the office or agency of the
Trustee therein specified. The Trustee shall give such notice to the Registrar
at the time such notice is given to Certificateholders. Upon presentation and
surrender of the Certificates in accordance with such notice, the Trustee shall
cause to be distributed to Certificateholders such final payments.

            In the event that all of the Certificateholders shall not surrender
their Certificates for cancellation within six months after the date specified
in the above-mentioned written notice, the Trustee shall give a second written
notice to the remaining Certificateholders to surrender their Certificates for
cancellation and receive the final distribution with respect thereto. No
additional interest shall accrue on the Certificates after the Distribution Date
specified in the first written notice. In the event that any money held by the
Trustee for the payment of distributions on the Certificates shall remain
unclaimed for two years (or such lesser time as the Trustee shall be satisfied,
after sixty days' notice from the Company, is one month prior to the escheat
period provided under applicable law) after the final distribution date with
respect thereto, the Trustee shall pay to each Loan Trustee the appropriate
amount of money relating to such Loan Trustee and shall give written notice
thereof to the related Owner Trustees, the Owner Participants and the Company.


                                   ARTICLE XII

                            MISCELLANEOUS PROVISIONS

            Section 12.01. Limitation on Rights of Certificateholders. The death
or incapacity of any Certificateholder shall not operate to terminate this
Agreement or the Trust, nor entitle such Certificateholder's legal
representatives or heirs to claim an accounting or to take any action or
commence any proceeding in any court for a partition or winding up of the Trust,
nor otherwise affect the rights, obligations, and liabilities of the parties
hereto or any of them.
<PAGE>   58
                                      -53-


            Section 12.02. Certificates Nonassessable and Fully Paid. Except as
set forth in the last sentence of this Section 12.02, Certificateholders shall
not be personally liable for obligations of the Trust, the Fractional Undivided
Interests represented by the Certificates shall be nonassessable for any losses
or expenses of the Trust or for any reason whatsoever, and Certificates, upon
authentication thereof by the Trustee pursuant to Section 3.03, are and shall be
deemed fully paid. No Certificateholder shall have any right (except as
expressly provided herein) to vote or in any manner otherwise control the
operation and management of the Trust Property, the Trust, or the obligations of
the parties hereto, nor shall anything set forth herein, or contained in the
terms of the Certificates, be construed so as to constitute the
Certificateholders from time to time as partners or members of an association.
Neither the existence of the Trust nor any provision herein is intended to or
shall limit the liability the Certificateholders would otherwise incur if the
Certificateholders owned Trust Property as co-owners, or incurred any
obligations of the Trust, directly rather than through the Trust.

            Section 12.03. Notices. (a) Unless otherwise specifically provided
herein, all notices required under the terms and provisions of this Agreement
shall be in English and in writing, and any such notice may be given by United
States mail, courier service or telecopy, and any such notice shall be effective
when received or, if made, given, furnished or filed by facsimile or
telecommunication transmission, when received unless received outside of
business hours, in which case on the next open of business on a Business Day,

            if to the Company, to:

                  America West Airlines, Inc.
                  4000 East Sky Harbor Boulevard
                  Phoenix, Arizona  85043

                  Attention: Vice President-
                             Treasurer
                  Facsimile: (602) 693-5886


            if to the Trustee, to:

                  Wilmington Trust Company
                  Rodney Square North
                  1100 North Market Street
                  Wilmington, Delaware  19890-0001

                  Attention: Corporate Trust Department
                  Facsimile: (302) 651-8882
                  Telephone: (302) 651-8584

            (b) The Company or the Trustee, by notice to the other, may
designate additional or different addresses for subsequent notices or
communications.

            (c) Any notice or communication to Certificateholders shall be
mailed by first-class mail to the addresses for Certificateholders shown on the
Register kept by the 
<PAGE>   59
                                      -54-


Registrar. Failure so to mail a notice or communication or any defect in such
notice or communication shall not affect its sufficiency with respect to other
Certificateholders.

            (d) If a notice or communication is mailed in the manner provided
above within the time prescribed, it is conclusively presumed to have been duly
given, whether or not the addressee receives it.

            (e) If the Company mails a notice or communication to the
Certificateholders, it shall mail a copy to the Trustee and to the Paying Agent
at the same time.

            (f) Notwithstanding the foregoing, all communications or notices to
the Trustee shall be deemed to be given only when received by a Responsible
Officer of the Trustee.

            (g) The Trustee shall promptly furnish the Company with a copy of
any demand, notice or written communication received by the Trustee hereunder
from any Certificateholder, Owner Trustee or Loan Trustee.

            Section 12.04. Governing Law. THIS AGREEMENT HAS BEEN DELIVERED IN
THE STATE OF NEW YORK AND THIS AGREEMENT AND THE CERTIFICATES SHALL BE GOVERNED
BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK AND THE
OBLIGATIONS, RIGHTS AND REMEDIES OF THE PARTIES HEREUNDER SHALL BE DETERMINED IN
ACCORDANCE WITH SUCH LAWS.

            Section 12.05. Severability of Provisions. If any one or more of the
covenants, agreements, provisions or terms of this Agreement shall be for any
reason whatsoever held invalid, then such covenants, agreements, provisions, or
terms shall be deemed severable from the remaining covenants, agreements,
provisions or terms of this Agreement and shall in no way affect the validity or
enforceability of the other provisions of this Agreement or the Trust, or of the
Certificates or the rights of the Certificateholders thereof.

            Section 12.06. Trust Indenture Act Controls. Upon the occurrence of
any Registration Event, this Agreement shall become subject to the provisions of
the Trust Indenture Act and shall, to the extent applicable, be governed by such
provisions. From and after any Registration Event, if any provision of this
Agreement limits, qualifies or conflicts with another provision which is
required to be included in this Agreement by the Trust Indenture Act, the
required provision shall control.

            Section 12.07. Effect of Headings and Table of Contents. The Article
and Section headings herein and the Table of Contents are for convenience only
and shall not affect the construction hereof.

            Section 12.08. Successors and Assigns. All covenants, agreements,
representations and warranties in this Agreement by the Trustee and the Company
shall bind and, to the extent permitted hereby, shall inure to the benefit of
and be enforceable by their respective successors and assigns, whether so
expressed or not.
<PAGE>   60
                                      -55-


            Section 12.09. Benefits of Agreement. Nothing in this Agreement or
in the Certificates, express or implied, shall give to any Person, other than
the parties hereto and their successors hereunder, and the Certificateholders,
any benefit or any legal or equitable right, remedy or claim under this
Agreement.

            Section 12.10. Legal Holidays. In any case where any Regular
Distribution Date or Special Distribution Date relating to any Certificate shall
not be a Business Day, then (notwithstanding any other provision of this
Agreement) payment need not be made on such date, but may be made on the next
succeeding Business Day with the same force and effect as if made on such
Regular Distribution Date or Special Distribution Date, and no interest shall
accrue during the intervening period.

            Section 12.11. Counterparts. For the purpose of facilitating the
execution of this Agreement and for other purposes, this Agreement may be
executed simultaneously in any number of counterparts, each of which
counterparts shall be deemed to be an original, and all of which counterparts
shall constitute but one and the same instrument.

            Section 12.12. Intention of Parties. The parties hereto intend that
the Trust be classified for U.S. federal income tax purposes as a grantor trust
under Subpart E, Part I of Subchapter J of the Internal Revenue Code of 1986, as
amended, and not as a trust or association taxable as a corporation or as a
partnership. Each Certificateholder and Investor, by its acceptance of its
Certificate or a beneficial interest therein, agrees to treat the Trust as a
grantor trust for all U.S. federal, state and local income tax purposes. The
powers granted and obligations undertaken pursuant to this Agreement shall be so
construed so as to further such intent.
<PAGE>   61

                                      -56-


            IN WITNESS WHEREOF, the parties have caused this Agreement to be
duly executed by their respective officers thereunto duly authorized as of the
day and year first written above.

                                    AMERICA WEST AIRLINES, INC.

                                    By: /s/ W. Douglas Parker 
                                       ----------------------------------
                                          Name: W. Douglas Parker
                                          Title: Sr. Vice President & CFO


                                    WILMINGTON TRUST COMPANY,
                                      as Trustee

                                    By: /s/ Jill K. Morrison
                                        ----------------------------------
                                          Name: Jill K. Morrison
                                          Title: Administrative Account Manager
<PAGE>   62
                                                                       EXHIBIT A

             FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION WITH
               TRANSFERS OF CERTIFICATES PURSUANT TO REGULATION S

                                                    [date]

Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE 19890-0001

Attention:  Corporate Trust Trustee Administration

      Re:   America West Airlines Pass Through Trust, Series 1998-1C-S
            (the "Trust") America West Airlines Pass Through Certificates,
            Series 1998-1C-S (the "Certificates")

Sirs:

            In connection with our proposed sale of $_____ Fractional Undivided
Interest of the Certificates, we confirm that such sale has been effected
pursuant to and in accordance with Regulation S under the Securities Act of
1933, as amended, and, accordingly, we represent that:

            (1) the offer of the Certificates was not made to a person in the
      United States or to or for the account or benefit of a U.S. person;

            (2) either (a) at the time the buy order was originated, the
      transferee was outside the United States or we and any person acting on
      our behalf reasonably believed that the transferee was outside the United
      States or (b) the transaction was executed in, on or through the
      facilities of a designated off-shore securities market and neither we nor
      any person acting on our behalf knows that the transaction has been
      pre-arranged with a buyer in the United States;

            (3) no directed selling efforts have been made in the United States
      in contravention of the requirements of Rule 903(a) or Rule 904(a) of
      Regulation S, as applicable; and

            (4) the transaction is not part of a plan or scheme to evade the
      registration requirements of the Securities Act.

            In addition, if the sale is made during a restricted period and the
provisions of Rule 903(b)(2) or Rule 904(b)(1) of Regulation S are applicable
thereto, we confirm that such sale has been made in accordance with the
applicable provisions of Rule 903(b)(2) or Rule 904(b)(1), as the case may be.

            You and America West Airlines, Inc. are entitled to rely upon this
letter and are irrevocably authorized to produce this letter or a copy hereof to
any interested party in any 
<PAGE>   63
                                       A-2


administrative or legal proceedings or official inquiry with respect to the
matters covered hereby. Terms used in this certificate have the meanings set
forth in Regulation S.

                                    Very truly yours,



                                    [Name of Transferor]
<PAGE>   64
                                                                       EXHIBIT B

                FORM OF CERTIFICATE TO BE DELIVERED IN CONNECTION
                        WITH TRANSFERS OF CERTIFICATES TO
                   NON-QIB INSTITUTIONAL ACCREDITED INVESTORS

                                                [date]

Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE 19890-0001
Attention:  Corporate Trust Trustee Administration

America West Airlines, Inc.
4000 East Sky Harbor Boulevard
Phoenix, Arizona  85043

                              AMERICA WEST AIRLINES
               PASS THROUGH TRUST, SERIES 1998-1C-S (the "Trust")
                 Pass Through Certificates, Series 1998-1C-S
                              (the "Certificates")


Ladies and Gentlemen:

            In connection with our proposed purchase of U.S. $[_____________]
Fractional Undivided Interest of Certificates, we confirm that:

            1. We understand that any subsequent transfer of the Certificates is
subject to certain restrictions and conditions set forth in the Pass Through
Trust Agreement, dated as of October 6, 1998, between America West Airlines,
Inc. (the "Company") and Wilmington Trust Company (the "Trustee") relating to
the Certificates, and we agree to be bound by, and not to resell, pledge or
otherwise transfer the Certificates except in compliance with, such restrictions
and conditions and the Securities Act of 1933, as amended (the "Securities
Act").

            2. We are purchasing Certificates having an aggregate principal
amount of not less than $100,000 and each account (if any) for which we are
purchasing Certificates is purchasing Certificates having an aggregate principal
amount of not less than $100,000.

            3. We understand that the Certificates have not been registered
under the Securities Act, that the Certificates are being sold to us in a
transaction that is exempt from the registration requirements of the Securities
Act and that the Certificates may not be offered or resold except as permitted
in the following sentence. We agree, on our own behalf and on behalf of any
accounts for which we are acting as hereinafter stated, that, if we should sell
any Certificates within three years after the later of the original issuance of
such Certificate and the last date on which such Certificate is owned by the
Company, the Trustee or any affiliate of any of such persons, we will do so only
(A) to the Company, (B) in accordance with Rule 144A 
<PAGE>   65
                                       B-2


under the Securities Act to a "qualified institutional buyer" (as defined
therein), (C) outside the United States in accordance with Rule 904 of
Regulation S under the Securities Act, (D) pursuant to the exemption from
registration provided by Rule 144 under the Securities Act or (E) pursuant to an
effective registration statement under the Securities Act, and we further agree
to provide to any person purchasing any of the Certificates from us a notice
advising such purchaser that resales of the Certificates are restricted as
stated herein.

            4. We understand that, on any proposed resale of any Certificates,
we will be required to furnish to the Company and the Trustee such
certifications, legal opinions and other information as the Trustee may
reasonably require to confirm that the proposed sale complies with the foregoing
restrictions. We further understand that the Certificates purchased by us will
bear a legend to the foregoing effect.

            5. We are an institutional "accredited investor" (as defined in Rule
501(a)(1), (2), (3) or (7) of Regulation D under the Securities Act) and have
such knowledge and experience in financial and business matters as to be capable
of evaluating the merits and risks of our investment in the Certificates, and we
and any accounts for which we are acting are each able to bear the economic risk
of our or their investments.

            6. We are acquiring the Certificates purchased by us for our own
account or for one or more accounts (each of which is an institutional
"accredited investor") as to each of which we exercise sole investment
discretion and not with a view to any distribution of the Certificates, subject,
nevertheless to the understanding that the disposition of our property shall at
all times be and remain within our control.

            You are entitled to rely upon this letter and are irrevocably
authorized to produce this letter or a copy thereof to any interested party in
any administrative or legal proceedings or official inquiry with respect to the
matters covered hereby.

                                    Very truly yours,


                                    By:_____________________________
                                        Name:
                                        Title:

<PAGE>   1
                                                                    EXHIBIT 4.10


                                                                       EXECUTION




                           REVOLVING CREDIT AGREEMENT
                                    (1998-1A)


                           Dated as of October 6, 1998

                                     between

                            WILMINGTON TRUST COMPANY,

                    not in its individual capacity but solely
                             as Subordination Agent,
                          as agent and trustee for the
                America West Airlines Pass Through Trust 1998-1A

                                   as Borrower

                                       and

                       ABN AMRO BANK N.V., CHICAGO BRANCH

                              as Liquidity Provider



                                   Relating to

                America West Airlines Pass Through Trust 1998-1A
             6.87% America West Airlines Pass Through Certificates,
                                 Series 1998-1A
<PAGE>   2
                                TABLE OF CONTENTS

                                                                            Page

                              ARTICLE I DEFINITIONS
Section 1.01.  Certain Defined Terms. .........................................1

                  ARTICLE II AMOUNT AND TERMS OF THE COMMITMENT
Section 2.01.  The Advances....................................................7
Section 2.02.  Making the Advances.............................................7
Section 2.03.  Fees............................................................8
Section 2.04.  Reduction or Termination of the Maximum Commitment..............8
Section 2.05.  Repayments of Interest Advances or the Final Advance............9
Section 2.06.  Repayments of Provider Advances.................................9
Section 2.07.  Payments to the Liquidity Provider Under the
               Intercreditor Agreement........................................10
Section 2.08.  Book Entries...................................................10
Section 2.09.  Payments from Available Funds Only.............................11
Section 2.10.  Extension of the Expiry Date; Non-Extension Advance............11

                     ARTICLE III OBLIGATIONS OF THE BORROWER
Section 3.01.  Increased Costs................................................12
Section 3.02.  Capital Adequacy...............................................13
Section 3.03.  Payments Free of Deductions....................................14
Section 3.04.  Payments.......................................................14
Section 3.05.  Computations...................................................14
Section 3.06.  Payment on Non-Business Days...................................15
Section 3.07.  Interest.......................................................15
Section 3.08.  Replacement of Borrower........................................16
Section 3.09.  Funding Loss Indemnification...................................16
Section 3.10.  Illegality.....................................................16

                         ARTICLE IV CONDITIONS PRECEDENT
Section 4.01.  Conditions Precedent to Effectiveness of Section 2.01..........17
Section 4.02.  Conditions Precedent to Borrowing..............................18

                               ARTICLE V COVENANTS
Section 5.01.  Affirmative Covenants of the Borrower..........................18
Section 5.02.  Negative Covenants of the Borrower.............................19

                     ARTICLE VI LIQUIDITY EVENTS OF DEFAULT
Section 6.01.  Liquidity Events of Default....................................19

                            ARTICLE VII MISCELLANEOUS
Section 7.01.  Amendments, Etc................................................19
Section 7.02.  Notices, Etc...................................................20
Section 7.03.  No Waiver; Remedies............................................20
Section 7.04.  Further Assurances.............................................21
Section 7.05.  Indemnification; Survival of Certain Provisions................21
Section 7.06.  Liability of the Liquidity Provider............................21



                                       i
<PAGE>   3
                                TABLE OF CONTENTS
                                   (CONTINUED)


Section 7.07.  Costs, Expenses and Taxes......................................21
Section 7.08.  Binding Effect; Participations.................................22
Section 7.09.  Severability...................................................23
Section 7.10.  Governing Law..................................................23
Section 7.11.  Submission to Jurisdiction; Waiver of Jury Trial; Waiver
               of Immunity....................................................23
Section 7.12.  Execution in Counterparts......................................24
Section 7.13.  Entirety.......................................................24
Section 7.14.  Headings.......................................................24
Section 7.15.  Transfer.......................................................25
Section 7.16.  Liquidity Provider's Obligation To Make Advances...............25


                                       ii
<PAGE>   4
                               TABLE OF CONTENTS
                                  (CONTINUED)

ANNEX I        Interest Advance Notice of Borrowing

ANNEX II       Non-Extension Advance Notice of Borrowing

ANNEX III      Downgrade Advance Notice of Borrowing

ANNEX IV       Final Advance Notice of Borrowing

ANNEX V        Notice of Termination

ANNEX VI       Notice of Replacement Subordination Agent


                                       iii
<PAGE>   5
                           REVOLVING CREDIT AGREEMENT

            This REVOLVING CREDIT AGREEMENT dated as of October 6, 1998, between
WILMINGTON TRUST COMPANY, a Delaware banking corporation, not in its individual
capacity but solely as Subordination Agent under the Intercreditor Agreement
(each as defined below), as agent and trustee for the Class A Trust (as defined
below) (the "Borrower"), and ABN AMRO BANK N.V., a bank organized under the laws
of the Netherlands, acting through its Chicago branch (the "Liquidity
Provider").

                              W I T N E S S E T H:

            WHEREAS, pursuant to the Class A Trust Agreement (such term and all
other capitalized terms used in these recitals having the meanings set forth or
referred to in Section 1.01), the Class A Trust is issuing the Class A
Certificates; and

            WHEREAS, the Borrower, in order to support the timely payment of a
portion of the interest on the Class A Certificates in accordance with their
terms, has requested the Liquidity Provider to enter into this Agreement,
providing in part for the Borrower to request in specified circumstances that
Advances be made hereunder.

            NOW, THEREFORE, in consideration of the premises, the parties hereto
agree as follows:


                                    ARTICLE I

                                   DEFINITIONS

            Section 1.01. Certain Defined Terms. (a) Definitions. As used in
this Agreement and unless otherwise expressly indicated, or unless the context
clearly requires otherwise, the following capitalized terms shall have the
following respective meanings for all purposes of this Agreement:

            "Additional Cost" has the meaning assigned to such term in Section
      3.01.

            "Advance" means an Interest Advance, a Final Advance, a Provider
      Advance, an Applied Provider Advance or an Unpaid Advance, as the case may
      be.

            "Applicable Liquidity Rate" has the meaning assigned to such term in
      Section 3.07(g).

            "Applicable Margin" means (A) with respect to any Unpaid Advance or
      Applied Provider Advance, (x) with respect to any LIBOR Advance, 1.75% and
      (y) with respect to any Base Rate Advance, 1%, and (B) with respect to any
      Unapplied Provider Advance, (x) with respect to any LIBOR Advance, .35%
      and (y) with respect to any Base Rate Advance, 0.
<PAGE>   6
                                                                               2


            "Applied Downgrade Advance" has the meaning assigned to such term in
      Section 2.06(a).

            "Applied Non-Extension Advance" has the meaning assigned to such
      term in Section 2.06(a).

            "Applied Provider Advance" has the meaning assigned to such term in
      Section 2.06(a).

            "Assignment and Assumption Agreement" means the Assignment and
      Assumption to be entered into between the Borrower and the trustee of the
      Successor Trust, substantially in the form of Exhibit D to the Class A
      Trust Agreement.

            "Base Rate" means a fluctuating interest rate per annum in effect
      from time to time, which rate per annum shall at all times be equal to (a)
      the weighted average of the rates on overnight Federal funds transactions
      with members of the Federal Reserve System arranged by Federal funds
      brokers, as published for such day (or, if such day is not a Business Day,
      for the next preceding Business Day) by the Federal Reserve Bank of New
      York, or if such rate is not so published for any day that is a Business
      Day, the average of the quotations for such day for such transactions
      received by the Liquidity Provider from three Federal funds brokers of
      recognized standing selected by it, plus (b) one quarter of one percent
      (1/4 of 1%).

            "Base Rate Advance" means an Advance that bears interest at a rate
      based upon the Base Rate.

            "Borrower" has the meaning assigned to such term in the recital of
      parties to this Agreement.

            "Borrowing" means the making of Advances requested by delivery of a
      Notice of Borrowing.

            "Business Day" means any day other than a Saturday or Sunday or a
      day on which commercial banks are required or authorized to close in
      Phoenix, Arizona, New York, New York, Chicago, Illinois or, so long as any
      Class A Certificate is outstanding, the city and state in which the Class
      A Trustee, the Borrower or any Loan Trustee maintains its Corporate Trust
      Office or receives or disburses funds, and, if the applicable Business Day
      relates to any Advance or other amount bearing interest based on the LIBOR
      Rate, on which dealings are carried on in the London interbank market.

            "Deposits" has the meaning assigned to such terms in the Deposit
      Agreement.

            "Depositary" has the meaning assigned to such term in the Deposit
      Agreement.

            "Deposit Agreement" means the Deposit Agreement dated October 6,
      1998 between Wilmington Trust Company, as Escrow Agent and ABN AMRO Bank
      N.V., acting through its Chicago branch, as Depositary, pertaining to the
      Class A Certificates, 
<PAGE>   7
                                                                               3


      as the same may be amended, modified or supplemented from time to time in
      accordance with the terms thereof.

            "Downgrade Advance" means an advance made pursuant to Section
      2.02(c).

            "Effective Date" has the meaning specified in Section 4.01. The
      delivery of the certificate of the Liquidity Provider contemplated by
      Section 4.01(e) shall be conclusive evidence that the Effective Date has
      occurred.

            "Excluded Taxes" means (i) taxes imposed on the overall net income,
      net worth, capital or franchise of the Liquidity Provider or of its
      Lending Office by the jurisdiction where such Liquidity Provider's
      principal office or such Lending Office is located, and (ii) Excluded
      Withholding Taxes.

            "Excluded Withholding Taxes" means (i) withholding Taxes imposed by
      the United States except (but only in the case of a successor Liquidity
      Provider organized under the laws of a jurisdiction outside the United
      States) to the extent that such United States withholding Taxes are
      imposed as a result of any change in applicable law (excluding from change
      in applicable law for this purpose a change in an applicable treaty or
      other change in law affecting the applicability of a treaty) after the
      date hereof, or in the case of a successor Liquidity Provider (including a
      transferee of an Advance) or Lending Office, after the date on which such
      successor Liquidity Provider obtains its interest or on which the Lending
      Office is changed, and (ii) any withholding Taxes imposed by the United
      States which are imposed or increased as a result of the Liquidity
      Provider failing to deliver to the Borrower any certificate or document
      (which certificate or document in the good faith judgment of the Liquidity
      Provider it is legally entitled to provide) which is reasonably requested
      by the Borrower to establish that payments under this Agreement are exempt
      from (or entitled to a reduced rate of) withholding Tax.

            "Expenses" means liabilities, obligations, damages, settlements,
      penalties, claims, actions, suits, costs, expenses, and disbursements
      (including, without limitation, reasonable fees and disbursements of legal
      counsel and costs of investigation), provided that Expenses shall not
      include any Taxes.

            "Expiry Date" means October 4, 1999, initially, or any date to which
      the Expiry Date is extended pursuant to Section 2.10.

            "Final Advance" means an advance made pursuant to Section 2.02(d).

            "Intercreditor Agreement" means the Intercreditor Agreement dated
      the date hereof, among the Trustees, the Liquidity Provider, the liquidity
      provider under each Liquidity Facility (other than this Agreement) and the
      Subordination Agent, as the same may be amended, supplemented or otherwise
      modified from time to time in accordance with its terms.

            "Interest Advance" means an advance made pursuant to Section
      2.02(a).
<PAGE>   8
                                                                               4


            "Interest Period" means, with respect to any LIBOR Advance, each of
      the following periods:

            (i)   the period beginning on the third Business Day following 
                  either (x) the Liquidity Provider's receipt of the Notice
                  of Borrowing for such LIBOR Advance (or, in the case of an
                  Unapplied Downgrade Advance, the period beginning on the
                  Expiry Date) or (y) the withdrawal of funds from the Class
                  A Cash Collateral Account for the purpose of paying
                  interest on the Class A Certificates as contemplated by
                  Section 2.06(a) hereof and, in either case, ending on the
                  next Regular Distribution Date; and

            (ii)  each subsequent period commencing on the last day of the
                  immediately preceding Interest Period and ending on the next
                  Regular Distribution Date;

      provided, however, that if (x) the Final Advance shall have been made, or
      (y) other outstanding Advances shall have been converted into the Final
      Advance, then the Interest Periods shall be successive periods of one
      month beginning on the third Business Day following the Liquidity
      Provider's receipt of the Notice of Borrowing for such Final Advance (in
      the case of clause (x) above) or the last day of the Interest Period then
      applicable to such outstanding Advances (in the case of clause (y) above).

            "Lending Office" means the office of the Liquidity Provider in which
      it books this facility presently located at Chicago, Illinois, or such
      other office as the Liquidity Provider from time to time shall notify the
      Borrower as its "Lending Office" hereunder in which it books this
      facility; provided that the Liquidity Provider shall not change its
      Lending Office to a Lending Office outside the United States of America
      except in accordance with Section 3.01, 3.02 or 3.03 hereof.

            "LIBOR Advance" means an Advance bearing interest at a rate based
      upon the LIBOR Rate.

            "LIBOR Rate" means, with respect to any Interest Period, the rate
      per annum appearing on Page 3750 of the Dow Jones Markets Service (or any
      successor or substitute Page of such Service, or any successor to or
      substitute for such Service, providing rate quotations comparable to those
      currently provided on such Page applicable to deposits in dollars in the
      London interbank market) at approximately 11:00 A.M. (London time) two
      Business Days before the first day of such Interest Period for a period of
      time comparable to such Interest Period. In the event that such rate is
      not available at such time for any reason, then the LIBOR Rate with
      respect to any Interest Period shall be the rate per annum at which
      deposits in dollars are offered to major banks in the London interbank
      market at approximately 11:00 A.M. (London time) two Business Days before
      the first day of such Interest Period for a period of time comparable to
      such Interest Period.

            "Liquidity Event of Default" means the occurrence of either (a) the
      Acceleration of all of the Equipment Notes (provided that, with respect to
      the period prior to the Delivery Period Expiry Date, such Equipment Notes
      have an aggregate outstanding principal balance in excess of $125,000,000)
      or (b) an America West Bankruptcy Event.
<PAGE>   9
                                                                               5


            "Liquidity Indemnitee" means (i) the Liquidity Provider, (ii) the
      directors, officers, employees and agents of the Liquidity Provider, and
      (iii) the successors and permitted assigns of the persons described in
      clauses (i) and (ii), inclusive.

            "Liquidity Provider" has the meaning assigned to such term in the
      recital of parties to this Agreement.

            "Maximum Available Commitment" means, subject to the proviso
      contained in the third sentence of Section 2.02(a), at any time of
      determination, (a) the Maximum Commitment at such time less (b) the
      aggregate amount of each Interest Advance outstanding at such time;
      provided that following a Provider Advance or a Final Advance, the Maximum
      Available Commitment shall be zero.

            "Maximum Commitment" means initially $14,556,119, as the same may be
      reduced from time to time in accordance with Section 2.04(a).

            "Non-Extension Advance" means an advance made pursuant to Section
      2.02(b).

            "Notice of Borrowing" has the meaning specified in Section 2.02(e).

            "Notice of Replacement Subordination Agent" has the meaning
      specified in Section 3.08.

            "Offering Memorandum" means the Offering Memorandum dated September
      24, 1998 relating to the Certificates, as such Offering Memorandum may be
      amended or supplemented.

            "Performing Note Deficiency" means any time that less than 65% of
      the then aggregate outstanding principal amount of all Equipment Notes are
      Performing Equipment Notes.

            "Provider Advance" means a Downgrade Advance or a Non-Extension
      Advance.

            "Regulatory Change" has the meaning assigned to such term in Section
      3.01.

            "Replenishment Amount" has the meaning assigned to such term in
      Section 2.06(b).

            "Required Amount" means, for any day, the sum of the aggregate
      amount of interest, calculated at the rate per annum equal to the Stated
      Interest Rate for the Class A Certificates, that would be payable on the
      Class A Certificates on each of the three successive semiannual Regular
      Distribution Dates immediately following such day or, if such day is a
      Regular Distribution Date, on such day and the succeeding two semiannual
      Regular Distribution Dates, in each case calculated on the basis of the
      Pool Balance of the Class A Certificates on such day and without regard to
      expected future payments of principal on the Class A Certificates.
<PAGE>   10
                                                                               6


            "Successor Trust" means America West Airlines Pass Through Trust
      1998-1A-S.

            "Termination Date" means the earliest to occur of the following: (i)
      the Expiry Date; (ii) the date on which the Borrower delivers to the
      Liquidity Provider a certificate, signed by a Responsible Officer of the
      Borrower, certifying that all of the Class A Certificates have been paid
      in full (or provision has been made for such payment in accordance with
      the Intercreditor Agreement and the Trust Agreements) or are otherwise no
      longer entitled to the benefits of this Agreement; (iii) the date on which
      the Borrower delivers to the Liquidity Provider a certificate, signed by a
      Responsible Officer of the Borrower, certifying that a Replacement
      Liquidity Facility has been substituted for this Agreement in full
      pursuant to Section 3.6(e) of the Intercreditor Agreement; (iv) the fifth
      Business Day following the receipt by the Borrower of a Termination Notice
      from the Liquidity Provider pursuant to Section 6.01 hereof; and (v) the
      date on which no Advance is or may (including by reason of reinstatement
      as herein provided) become available for a Borrowing hereunder.

            "Termination Notice" means the Notice of Termination substantially
      in the form of Annex V to this Agreement.

            "Transferee" has the meaning assigned to such term in Section
      7.08(b).

            "Unapplied Downgrade Advance" means any Downgrade Advance other than
      an Applied Downgrade Advance.

            "Unapplied Provider Advance" means any Provider Advance other than
      an Applied Provider Advance.

            "Unpaid Advance" has the meaning assigned to such term in Section
      2.05.

            (b) Terms Defined in the Intercreditor Agreement. For all purposes
of this Agreement, the following terms shall have the respective meanings
assigned to such terms in the Intercreditor Agreement:

      "Acceleration", "America West", "America West Bankruptcy Event",
      "Certificates", "Class A Cash Collateral Account", "Class A Certificates",
      "Class A Certificateholders", "Class A Trust", "Class A Trust Agreement",
      "Class A Trustee", "Class B Certificates", "Class C Certificates",
      "Closing Date", "Controlling Party", "Corporate Trust Office", "Delivery
      Period Expiry Date", "Distribution Date", "Downgraded Facility",
      "Equipment Notes", "Fee Letter", "Final Legal Distribution Date",
      "Financing Agreement", "Indenture", "Initial Purchasers", "Interest
      Payment Date", "Investment Earnings", "Liquidity Facility", "Liquidity
      Obligations", "Loan Trustee", "Moody's", "Non-Extended Facility", "Note
      Purchase Agreement", "Operative Agreements", "Performing Equipment Note",
      "Person", "Pool Balance", "Purchase Agreement", "Rating Agency", "Ratings
      Confirmation", "Regular Distribution Date", "Replacement Liquidity
      Facility", "Responsible Officer", "Scheduled Payment", "Special Payment",
      "Standard & Poor's", "Stated Interest Rate", "Subordination Agent",
      "Taxes", "Threshold Rating", "Transfer", "Trust Agreements", "Trustee",
      and "Written Notice".
<PAGE>   11
                                                                               7


                                   ARTICLE II

                       AMOUNT AND TERMS OF THE COMMITMENT

            Section 2.01. The Advances. The Liquidity Provider hereby
irrevocably agrees, on the terms and conditions hereinafter set forth, to make
Advances to the Borrower from time to time on any Business Day during the period
from the Effective Date until 12:00 Noon (New York City time) on the Expiry Date
(unless the obligations of the Liquidity Provider shall be earlier terminated in
accordance with the terms of Section 2.04(b)) in an aggregate amount at any time
outstanding not to exceed the Maximum Commitment.

            Section 2.02. Making the Advances. (a) Interest Advances shall be
made in one or more Borrowings by delivery to the Liquidity Provider of one or
more written and completed Notices of Borrowing in substantially the form of
Annex I attached hereto, signed by a Responsible Officer of the Borrower, in an
amount not exceeding the Maximum Available Commitment at such time and shall be
used solely for the payment when due of interest on the Class A Certificates at
the Stated Interest Rate therefor in accordance with Section 3.6(a) of the
Intercreditor Agreement. Each Interest Advance made hereunder shall
automatically reduce the Maximum Available Commitment by the amount of such
Interest Advance (subject to reinstatement as provided in the next sentence).
Upon repayment to the Liquidity Provider in full of the amount of any Interest
Advance made pursuant to this Section 2.02(a), together with accrued interest
thereon (as provided herein), the Maximum Available Commitment shall be
reinstated by the amount of such repaid Interest Advance, but not to exceed the
Maximum Commitment; provided, however, that the Maximum Available Commitment
shall not be so reinstated at any time if (i) a Liquidity Event of Default shall
have occurred and be continuing and (ii) there is a Performing Note Deficiency.

            (b) A Non-Extension Advance shall be made in a single Borrowing if
this Agreement is not extended in accordance with Section 3.6(d) of the
Intercreditor Agreement (unless a Replacement Liquidity Facility to replace this
Agreement shall have been delivered to the Borrower as contemplated by said
Section 3.6(d) within the time period specified in such Section) by delivery to
the Liquidity Provider of a written and completed Notice of Borrowing in
substantially the form of Annex II attached hereto, signed by a Responsible
Officer of the Borrower, in an amount equal to the Maximum Available Commitment
at such time, and shall be used to fund the Class A Cash Collateral Account in
accordance with said Section 3.6(d) and Section 3.6(f) of the Intercreditor
Agreement.

            (c) A Downgrade Advance shall be made in a single Borrowing upon a
downgrading of the Liquidity Provider's short-term unsecured debt rating issued
by either Rating Agency below the applicable Threshold Rating (as provided for
in Section 3.6(c) of the Intercreditor Agreement) unless a Replacement Liquidity
Facility to replace this Agreement shall have been previously delivered to the
Borrower in accordance with said Section 3.6(c), by delivery to the Liquidity
Provider of a written and completed Notice of Borrowing in substantially the
form of Annex III attached hereto, signed by a Responsible Officer of the
Borrower, in an amount equal to the Maximum Available Commitment at such time,
and shall be used to fund the Class A Cash Collateral Account in accordance with
said Section 3.6(c) and Section 3.6(f) of the Intercreditor Agreement.
<PAGE>   12
                                                                               8


            (d) A Final Advance shall be made in a single Borrowing upon the
receipt by the Borrower of a Termination Notice from the Liquidity Provider
pursuant to Section 6.01 hereof by delivery to the Liquidity Provider of a
written and completed Notice of Borrowing in substantially the form of Annex IV
attached hereto, signed by a Responsible Officer of the Borrower, in an amount
equal to the Maximum Available Commitment at such time, and shall be used to
fund the Class A Cash Collateral Account (in accordance with Section 3.6(i) of
the Intercreditor Agreement) and Section 3.6(f) of the Intercreditor Agreement.

            (e) Each Borrowing shall be made on notice in writing (a "Notice of
Borrowing") in substantially the form required by Section 2.02(a), 2.02(b),
2.02(c) or 2.02(d), as the case may be, given by the Borrower to the Liquidity
Provider. If a Notice of Borrowing is delivered by the Borrower in respect of
any Borrowing no later than 1:00 p.m. (New York City time) on a Business Day,
upon satisfaction of the conditions precedent set forth in Section 4.02 with
respect to a requested Borrowing, the Liquidity Provider shall make available to
the Borrower, in accordance with its payment instructions, the amount of such
Borrowing in U.S. dollars and immediately available funds, before 3:00 p.m. (New
York City time) on such Business Day or on such later Business Day specified in
such Notice of Borrowing. If a Notice of Borrowing is delivered by the Borrower
in respect of any Borrowing after 1:00 p.m. (New York City time) on a Business
Day, upon satisfaction of the conditions precedent set forth in Section 4.02
with respect to a requested Borrowing, the Liquidity Provider shall make
available to the Borrower, in accordance with its payment instructions, the
amount of such Borrowing in U.S. dollars and immediately available funds, before
12:00 Noon (New York City time) on the first Business Day next following the day
of receipt of such Notice of Borrowing or on such later Business Day specified
by the Borrower in such Notice of Borrowing. Payments of proceeds of a Borrowing
shall be made by wire transfer of immediately available funds to the Borrower in
accordance with such wire transfer instructions as the Borrower shall furnish
from time to time to the Liquidity Provider for such purpose. Each Notice of
Borrowing shall be irrevocable and binding on the Borrower.

            (f) Upon the making of any Advance requested pursuant to a Notice of
Borrowing, in accordance with the Borrower's payment instructions, the Liquidity
Provider shall be fully discharged of its obligation hereunder with respect to
such Notice of Borrowing, and the Liquidity Provider shall not thereafter be
obligated to make any further Advances hereunder in respect of such Notice of
Borrowing to the Borrower or to any other Person. Following the making of any
Advance pursuant to Section 2.02(b), (c) or (d) hereof to fund the Class A Cash
Collateral Account, the Liquidity Provider shall have no interest in or rights
to the Class A Cash Collateral Account, such Advance or any other amounts from
time to time on deposit in the Class A Cash Collateral Account; provided that
the foregoing shall not affect or impair the obligations of the Subordination
Agent to make the distributions contemplated by Section 3.6(e) or (f) of the
Intercreditor Agreement. By paying to the Borrower proceeds of Advances
requested by the Borrower in accordance with the provisions of this Agreement,
the Liquidity Provider makes no representation as to, and assumes no
responsibility for, the correctness or sufficiency for any purpose of the amount
of the Advances so made and requested.

            Section 2.03. Fees. The Borrower agrees to pay to the Liquidity
Provider the fees set forth in the Fee Letter.

            Section 2.04. Adjustments or Termination of the Maximum Commitment.
<PAGE>   13
                                                                               9


            (a) Automatic Adjustments. Promptly following each date on which the
Required Amount is (1) reduced as a result of a reduction in the Pool Balance of
the Class A Certificates or otherwise, (2) increased as a result of an increase
in the Stated Interest Rate or (3) subsequent to such an increase described in
clause (2), reduced pursuant to the definition of "Stated Interest Rate", the
Maximum Commitment shall automatically be reduced or increased, as the case may
be, to an amount equal to the Required Amount (as calculated by the Borrower).
The Borrower shall give notice of any such automatic reduction or increase, as
the case may be, of the Maximum Commitment to the Liquidity Provider within two
Business Days thereof. The failure by the Borrower to furnish any such notice
shall not affect such automatic reduction or increase of the Maximum Commitment.

            (b) Termination. Upon the making of any Provider Advance or Final
Advance hereunder or the occurrence of the Termination Date, the obligation of
the Liquidity Provider to make further Advances hereunder shall automatically
and irrevocably terminate, and the Borrower shall not be entitled to request any
further Borrowing hereunder.

            Section 2.05. Repayments of Interest Advances or the Final Advance.
Subject to Sections 2.06, 2.07 and 2.09 hereof, the Borrower hereby agrees,
without notice of an Advance or demand for repayment from the Liquidity Provider
(which notice and demand are hereby waived by the Borrower), to pay, or to cause
to be paid, to the Liquidity Provider on each date on which the Liquidity
Provider shall make an Interest Advance or the Final Advance, an amount equal to
(a) the amount of such Advance (any such Advance, until repaid, is referred to
herein as an "Unpaid Advance"), plus (b) interest on the amount of each such
Unpaid Advance as provided in Section 3.07 hereof; provided that if (i) the
Liquidity Provider shall make a Provider Advance at any time after making one or
more Interest Advances which shall not have been repaid in accordance with this
Section 2.05 or (ii) this Liquidity Facility shall become a Downgraded Facility
or Non-Extended Facility at any time when unreimbursed Interest Advances have
reduced the Maximum Available Commitment to zero, then such Interest Advances
shall cease to constitute Unpaid Advances and shall be deemed to have been
changed into an Applied Downgrade Advance or an Applied Non-Extension Advance,
as the case may be, for all purposes of this Agreement (including, without
limitation, for the purpose of determining when such Interest Advance is
required to be repaid to the Liquidity Provider in accordance with Section 2.06
and for the purposes of Section 2.06(b)). The Borrower and the Liquidity
Provider agree that the repayment in full of each Interest Advance and Final
Advance on the date such Advance is made is intended to be a contemporaneous
exchange for new value given to the Borrower by the Liquidity Provider.

            Section 2.06. Repayments of Provider Advances. (a) Amounts advanced
hereunder in respect of a Provider Advance shall be deposited in the Class A
Cash Collateral Account, invested and withdrawn from the Class A Cash Collateral
Account as set forth in Sections 3.6(c), (d) and (f) of the Intercreditor
Agreement. The Borrower agrees to pay to the Liquidity Provider, on each Regular
Distribution Date, commencing on the first Regular Distribution Date after the
making of a Provider Advance, interest on the principal amount of any such
Provider Advance as provided in Section 3.07; provided, however, that amounts in
respect of a Provider Advance withdrawn from the Class A Cash Collateral Account
for the purpose of paying interest on the Class A Certificates in accordance
with Section 3.6(f) of the Intercreditor Agreement (the amount of any such
withdrawal being (y) in the case of a 
<PAGE>   14
                                                                              10


Downgrade Advance, an "Applied Downgrade Advance" and (z) in the case of a
Non-Extension Advance, an "Applied Non-Extension Advance" and, together with an
Applied Downgrade Advance, an "Applied Provider Advance") shall thereafter
(subject to Section 2.06(b)) be treated as an Interest Advance under this
Agreement for purposes of determining the Applicable Liquidity Rate for interest
payable thereon; provided further, however, that if, following the making of a
Provider Advance, the Liquidity Provider delivers a Termination Notice to the
Borrower pursuant to Section 6.01 hereof, such Provider Advance shall thereafter
be treated as a Final Advance under this Agreement for purposes of determining
the Applicable Liquidity Rate for interest payable thereon. Subject to Sections
2.07 and 2.09 hereof, immediately upon the withdrawal of any amounts from the
Class A Cash Collateral Account on account of a reduction in the Required
Amount, the Borrower shall repay to the Liquidity Provider a portion of the
Provider Advances in a principal amount equal to such reduction, plus interest
on the principal amount prepaid as provided in Section 3.07 hereof.

            (b) At any time when an Applied Provider Advance (or any portion
thereof) is outstanding, upon the deposit in the Class A Cash Collateral Account
of any amount pursuant to clause "third" of Section 2.4(b) of the Intercreditor
Agreement, clause "third" of Section 3.2 of the Intercreditor Agreement or
clause "fourth" of Section 3.3 of the Intercreditor Agreement (any such amount
being a "Replenishment Amount") for the purpose of replenishing or increasing
the balance thereof up to the Required Amount at such time, (i) the aggregate
outstanding principal amount of all Applied Provider Advances (and of Provider
Advances treated as an Interest Advance for purposes of determining the
Applicable Liquidity Rate for interest payable thereon) shall be automatically
reduced by the amount of such Replenishment Amount and (ii) the aggregate
outstanding principal amount of all Unapplied Provider Advances shall be
automatically increased by the amount of such Replenishment Amount.

            (c) Upon the provision of a Replacement Liquidity Facility in
replacement of this Agreement in accordance with Section 3.6(e) of the
Intercreditor Agreement, amounts remaining on deposit in the Class A Cash
Collateral Account after giving effect to any Applied Provider Advance on the
date of such replacement shall be reimbursed to the Liquidity Provider, but only
to the extent such amounts are necessary to repay in full to the Liquidity
Provider all amounts owing to it hereunder.

            Section 2.07. Payments to the Liquidity Provider Under the
Intercreditor Agreement. In order to provide for payment or repayment to the
Liquidity Provider of any amounts hereunder, the Intercreditor Agreement
provides that amounts available and referred to in Articles II and III of the
Intercreditor Agreement, to the extent payable to the Liquidity Provider
pursuant to the terms of the Intercreditor Agreement (including, without
limitation, Section 3.6(f) of the Intercreditor Agreement), shall be paid to the
Liquidity Provider in accordance with the terms thereof. Amounts so paid to the
Liquidity Provider shall be applied by the Liquidity Provider to Liquidity
Obligations then due and payable in accordance with the Intercreditor Agreement
or, if not provided for in the Intercreditor Agreement, then in such manner as
the Liquidity Provider shall deem appropriate.

            Section 2.08. Book Entries. The Liquidity Provider shall maintain in
accordance with its usual practice an account or accounts evidencing the
indebtedness of the Borrower resulting from Advances made from time to time and
the amounts of principal and interest payable hereunder and paid from time to
time in respect thereof; provided, however, that the 
<PAGE>   15
                                                                              11


failure by the Liquidity Provider to maintain such account or accounts shall not
affect the obligations of the Borrower in respect of Advances.

            Section 2.09. Payments from Available Funds Only. All payments to be
made by the Borrower under this Agreement shall be made only from the amounts
that constitute Scheduled Payments, Special Payments or payments under Section
7.1 or 9.1, as the case may be, of the Participation Agreements and Section 6 of
the Note Purchase Agreement and only to the extent that the Borrower shall have
sufficient income or proceeds therefrom to enable the Borrower to make payments
in accordance with the terms hereof after giving effect to the priority of
payments provisions set forth in the Intercreditor Agreement. The Liquidity
Provider agrees that it will look solely to such amounts to the extent available
for distribution to it as provided in the Intercreditor Agreement and this
Agreement and that the Borrower, in its individual capacity, is not personally
liable to it for any amounts payable or liability under this Agreement except as
expressly provided in this Agreement, the Intercreditor Agreement or any
Participation Agreement. Amounts on deposit in the Class A Cash Collateral
Account shall be available to the Borrower to make payments under this Agreement
only to the extent and for the purposes expressly contemplated in Section 3.6(f)
of the Intercreditor Agreement.

            Section 2.10. Extension of the Expiry Date; Non-Extension Advance.
No earlier than the 60th day and no later than the 40th day prior to the then
effective Expiry Date (unless such Expiry Date is on or after the date that is
15 days after the Final Legal Distribution Date for the Class A Certificates),
the Borrower shall request that the Liquidity Provider extend the Expiry Date
for a period of 364 days after the then effective Expiry Date (unless the
obligations of the Liquidity Provider are earlier terminated in accordance with
the terms hereof). The Liquidity Provider shall advise the Borrower, no earlier
than 40 days and no later than 25 days prior to the then effective Expiry Date,
whether, in its sole discretion, it agrees to so extend the Expiry Date. If the
Liquidity Provider advises the Borrower on or before the 25th day prior to the
Expiry Date then in effect that such Expiry Date shall not be so extended, or
fails to irrevocably and unconditionally advise the Borrower on or before the
25th day prior to the Expiry Date then in effect that such Expiry Date shall be
so extended (and, in each case, if the Liquidity Provider shall not have been
replaced in accordance with Section 3.6(e) of the Intercreditor Agreement), the
Borrower shall be entitled on and after such 25th day (but prior to the then
effective Expiry Date) to request a Non-Extension Advance in accordance with
Section 2.02(b) hereof and Section 3.6(d) of the Intercreditor Agreement.
<PAGE>   16
                                                                              12


                                   ARTICLE III

                           OBLIGATIONS OF THE BORROWER

            Section 3.01. Increased Costs. The Borrower shall pay to the
Liquidity Provider from time to time such amounts as may be necessary to
compensate the Liquidity Provider for any increased costs incurred by the
Liquidity Provider which are reasonably attributable to its making or
maintaining any LIBOR Advances hereunder or its obligation to make any such
Advances hereunder, or any reduction in any amount receivable by the Liquidity
Provider under this Agreement or the Intercreditor Agreement in respect of any
such Advances or such obligation (such increases in costs and reductions in
amounts receivable being herein called "Additional Costs"), resulting from any
change after the date of this Agreement in U.S. federal, state, municipal, or
foreign laws or regulations (including Regulation D of the Board of Governors of
the Federal Reserve System applicable to banks generally), or the adoption or
making after the date of this Agreement of any interpretations, directives, or
requirements applying to a class of banks including the Liquidity Provider under
any U.S. federal, state, municipal, or any foreign laws or regulations (whether
or not having the force of law but of the type with which the Liquidity Provider
is accustomed to comply) by any court, central bank or monetary authority
charged with the interpretation or administration thereof in each case not
publicly announced on the date hereof (a "Regulatory Change"), which: (1)
changes the basis of taxation of any amounts payable to the Liquidity Provider
under this Agreement in respect of any such Advances (other than Excluded
Taxes); or (2) imposes or modifies any reserve, special deposit, compulsory loan
or similar requirements relating to any extensions of credit hereunder in
respect of LIBOR Advances (including any such Advances or any deposits referred
to in the definition of LIBOR Rate or related definitions), other than (i) costs
which arise as a result of the Liquidity Provider willfully contravening or
exceeding any operating limits or other restrictions imposed on it by any
authority; or (ii) if the increased costs would not have arisen but for any
assignment to another Liquidity Provider or an alteration in the lending office
of the Liquidity Provider. The Liquidity Provider agrees to use reasonable
efforts (consistent with applicable legal and regulatory restrictions) to change
the jurisdiction of its Lending Office if making such change would avoid the
need for, or reduce the amount of, any amount payable under this Section that
may thereafter accrue and would not, in the reasonable judgment of the Liquidity
Provider, be otherwise materially disadvantageous to the Liquidity Provider.

            The Liquidity Provider will notify the Borrower of any event
occurring after the date of this Agreement that will entitle the Liquidity
Provider to compensation pursuant to this Section 3.01 as promptly as
practicable after it obtains knowledge thereof and determines to request such
compensation, which notice shall describe in reasonable detail the calculation
of the amounts owed under this Section; provided, that if the Liquidity Provider
fails to give such notice within 30 days after it obtains such knowledge, the
Liquidity Provider shall, with respect to any costs resulting from such event,
only be entitled to payment under this Section 3.01 for costs incurred from and
after the date 30 days prior to the date the Liquidity Provider does give such
notice. Determinations by the Liquidity Provider for purposes of this Section
3.01 of the effect of any Regulatory Change on its costs of making or
maintaining Advances or on amounts receivable by it in respect of Advances, and
of the additional amounts required to compensate the Liquidity Provider in
respect of any Additional Costs, shall be prima facie evidence of the amount
owed under this Section.
<PAGE>   17
                                                                              13


            The Liquidity Provider shall not be entitled to compensation under
this Section 3.01 if (1) it shall not be also seeking compensation (if it should
be so entitled) under other comparable contractual provisions in its other
agreements, (2) if its claim under this Section 3.01 arises through
circumstances peculiar to the Liquidity Provider and which do not affect a
similarly organized commercial banking institution in the same jurisdiction
generally, or (3) the Liquidity Provider is not the initial liquidity provider
and America West did not consent to the transfer of this facility to the
Liquidity Provider, for the amount, if any, payable under this Section 3.01
resulting from events occurring prior to the date the Liquidity Provider
acquired its interests hereunder as shall exceed the amount payable under this
Section 3.01 that would have been due to the Liquidity Provider's transferor had
it continued to be the liquidity provider hereunder.

            Section 3.02. Capital Adequacy. If (1) the adoption, after the date
hereof, of any applicable governmental law, rule or regulation regarding capital
adequacy and not publicly announced on the date hereof, (2) any change, after
the date hereof, in the interpretation or administration of any such law, rule
or regulation by any central bank or other governmental authority charged with
the interpretation or administration thereof and not publicly announced on the
date hereof or (3) compliance by the Liquidity Provider or any corporation
controlling the Liquidity Provider with any applicable guideline or request of
general applicability, issued after the date hereof and not publicly announced
on the date hereof, by any central bank or other governmental authority (whether
or not having the force of law but of the type with which the Liquidity Provider
is accustomed to comply) that constitutes a change of the nature described in
clause (2), has the effect of requiring an increase in the amount of capital
required to be maintained by the Liquidity Provider or any corporation
controlling the Liquidity Provider, and such increase is based upon the
Liquidity Provider's obligations hereunder and other similar obligations, the
Borrower shall pay to the Liquidity Provider from time to time such additional
amount or amounts as are necessary to compensate the Liquidity Provider for such
portion of such increase as shall be reasonably allocable to the Liquidity
Provider's obligations to the Borrower hereunder. The Liquidity Provider agrees
to use reasonable efforts (consistent with applicable legal and regulatory
restrictions) to change the jurisdiction of its Lending Office if making such
change would avoid the need for, or reduce the amount of, any amount payable
under this Section that may thereafter accrue and would not, in the reasonable
judgment of the Liquidity Provider, be otherwise materially disadvantageous to
the Liquidity Provider.

            The Liquidity Provider will notify the Borrower of any event
occurring after the date of this Agreement that will entitle the Liquidity
Provider to compensation pursuant to this Section 3.02 as promptly as
practicable after it obtains knowledge thereof and determines to request such
compensation, which notice shall describe in reasonable detail the calculation
of the amounts owed under this Section; provided that if the Liquidity Provider
fails to give such notice within 30 days after it obtains such knowledge, the
Liquidity Provider shall, with respect of any costs resulting from such event,
only be entitled to payment under this Section 3.02 for costs incurred from and
after the date 30 days prior to the date the Liquidity Provider does give such
notice. Determinations by the Liquidity Provider for purposes of this Section
3.02 of the effect of any increase in the amount of capital required to be
maintained by the Liquidity Provider and of the amount allocable to the
Liquidity Provider's obligations to the Borrower hereunder shall be prima facie
evidence of the amounts owed under this Section.
<PAGE>   18
                                                                              14


            The Liquidity Provider shall not be entitled to compensation under
this Section 3.02 if (1) it shall not be also seeking compensation (if it should
be so entitled) under other comparable contractual provisions in its other
agreements, (2) if its claim under this Section 3.02 arises through
circumstances peculiar to the Liquidity Provider and which do not affect a
similarly organized commercial banking institution in the same jurisdiction
generally, or (3) the Liquidity Provider is not the initial liquidity provider
and America West did not consent to the transfer of this facility to the
Liquidity Provider, for the amount, if any, payable under this Section 3.02
resulting from events occurring prior to the date the Liquidity Provider
acquired its interests hereunder as shall exceed the amount payable under this
Section 3.02 that would have been due to the Liquidity Provider's transferor had
it continued to be the liquidity provider hereunder.

            Section 3.03. Payments Free of Deductions. (a) All payments made by
the Borrower under this Agreement shall be made free and clear of, and without
reduction for or on account of, any present or future stamp or other taxes,
levies, imposts, duties, deductions or withholdings, of a similar nature other
than Excluded Taxes (collectively, "Non-Excluded Taxes" and, individually, a
"Non-Excluded Tax"). If any Non-Excluded Taxes are required to be withheld from
any amounts payable to the Liquidity Provider under this Agreement, the
Liquidity Provider shall notify the Borrower and America West thereof and from
and after such notice, the amounts so payable to the Liquidity Provider shall be
increased to the extent necessary to yield to the Liquidity Provider (after
payment of all Non-Excluded Taxes) the amount it would have received had no such
deduction or withholding occurred. The Liquidity Provider agrees to use
reasonable efforts (consistent with its legal and regulatory restrictions) to
change the jurisdiction of its Lending Office if making such change would avoid
the need for, or reduce the amount of, any such additional amounts that may
thereafter accrue and shall otherwise take such reasonable steps as are open to
it to mitigate the effects of such circumstances provided that the Liquidity
Provider shall be under no obligation to take any such action if to do so would
have a material adverse effect on its business, operations or financial
condition or result in its rights, interests or position under this Agreement
being prejudiced or involved in any unlawful activity. From time to time upon
the reasonable request of the Borrower, the Liquidity Provider agrees to provide
to the Borrower two original Internal Revenue Service Form 1001 or 4224, as
appropriate, or any successor or other form prescribed by the Internal Revenue
Service, certifying that the Liquidity Provider is exempt from or entitled to a
reduced rate of United States withholding tax on payments pursuant to this
Agreement.

            Section 3.04. Payments. The Borrower shall make or cause to be made
each payment to the Liquidity Provider under this Agreement so as to cause the
same to be received by the Liquidity Provider not later than 1:00 P.M. (New York
City time) on the day when due. The Borrower shall make all such payments in
lawful money of the United States of America, to the Liquidity Provider in
immediately available funds, by wire transfer to ABN AMRO Bank N.V., New York,
New York, ABA # 026009580 for account of ABN AMRO Bank N.V., Chicago Branch CPU,
Account No. 650-001-1789-41, Account Reference: America West Airlines Liquidity
Facility 1998-1A.

            Section 3.05. Computations. All computations of interest based on
the Base Rate shall be made on the basis of a year of 365 or 366 days, as the
case may be, and all computations of interest based on the LIBOR Rate shall be
made on the basis of a year of 360 days, in each 
<PAGE>   19
                                                                              15


case for the actual number of days (including the first day but excluding the
last day) occurring in the period for which such interest is payable.

            Section 3.06. Payment on Non-Business Days. Whenever any payment to
be made hereunder shall be stated to be due on a day other than a Business Day,
such payment shall be made on the next succeeding Business Day and no additional
interest shall be due as a result (and if so made, shall be deemed to have been
made when due). If any payment in respect of interest on an Advance is so
deferred to the next succeeding Business Day, such deferral shall not delay the
commencement of the next Interest Period for such Advance (if such Advance is a
LIBOR Advance) or reduce the number of days for which interest will be payable
on such Advance on the next interest payment date for such Advance.

            Section 3.07. Interest. (a) Subject to Section 2.09, the Borrower
shall pay, or shall cause to be paid, without duplication, interest on (i) the
unpaid principal amount of each Advance from and including the date of such
Advance (or, in the case of an Applied Provider Advance, from and including the
date on which the amount thereof was withdrawn from the Class A Cash Collateral
Account to pay interest on the Class A Certificates) to but excluding the date
such principal amount shall be paid in full (or, in the case of an Applied
Provider Advance, the date on which the Class A Cash Collateral Account is fully
replenished in respect of such Advance) and (ii) any other amount due hereunder
(whether fees, commissions, expenses or other amounts or, to the extent
permitted by law, installments of interest on Advances or any such other amount)
which is not paid when due (whether at stated maturity, by acceleration or
otherwise) from and including the due date thereof to but excluding the date
such amount is paid in full, in each such case, at a fluctuating interest rate
per annum for each day equal to the Applicable Liquidity Rate for such Advance
or such other amount as in effect for such day, but in no event at a rate per
annum greater than the maximum rate permitted by applicable law; provided,
however, that, if at any time the otherwise applicable interest rate as set
forth in this Section 3.07 shall exceed the maximum rate permitted by applicable
law, then any subsequent reduction in such interest rate will not reduce the
rate of interest payable pursuant to this Section 3.07 below the maximum rate
permitted by applicable law until the total amount of interest accrued equals
the amount of interest that would have accrued if such otherwise applicable
interest rate as set forth in this Section 3.07 had at all times been in effect.

            (b) Each Advance will be either a Base Rate Advance or a LIBOR
Advance as provided in this Section. Each such Advance will be a Base Rate
Advance for the period from the date of its borrowing to (but excluding) the
third Business Day following the Liquidity Provider's receipt of the Notice of
Borrowing for such Advance. Thereafter, such Advance shall be a LIBOR Advance.

            (c) Each LIBOR Advance shall bear interest during each Interest
Period at a rate per annum equal to the LIBOR Rate for such Interest Period plus
the Applicable Margin for such LIBOR Advance, payable in arrears on the last day
of such Interest Period and, in the event of the payment of principal of such
LIBOR Advance on a day other than such last day, on the date of such payment (to
the extent of interest accrued on the amount of principal repaid).

            (d) Each Base Rate Advance shall bear interest at a rate per annum
equal to the Base Rate plus the Applicable Margin for such Base Rate Advance,
payable in arrears on each Regular Distribution Date and, in the event of the
payment of principal of such Base Rate 
<PAGE>   20
                                                                              16


Advance on a day other than a Regular Distribution Date, on the date of such
payment (to the extent of interest accrued on the amount of principal repaid).

            (e) Each amount not paid when due hereunder (whether fees,
commissions, expenses or other amounts or, to the extent permitted by applicable
law, installments of interest on Advances but excluding Advances) shall bear
interest at a rate per annum equal to the Base Rate plus 2% until paid.

            (f) Each change in the Base Rate shall become effective immediately.
The rates of interest specified in this Section 3.07 with respect to any Advance
or other amount shall be referred to as the "Applicable Liquidity Rate".

            Section 3.08. Replacement of Subordination Agent. From time to time
and subject to the successor Subordination Agent's meeting the eligibility
requirements set forth in Section 6.9 of the Intercreditor Agreement applicable
to the Subordination Agent, upon the effective date and time specified in a
written and completed Notice of Replacement Subordination Agent in substantially
the form of Annex VI attached hereto (a "Notice of Replacement Subordination
Agent") delivered to the Liquidity Provider by the then Subordination Agent, the
successor Subordination Agent designated therein shall be substituted for as the
Subordination Agent for all purposes hereunder.

            Section 3.09. Funding Loss Indemnification. The Borrower shall pay
to the Liquidity Provider, upon the request of the Liquidity Provider, such
amount or amounts as shall be sufficient (in the reasonable opinion of the
Liquidity Provider) to compensate it for any loss incurred by it by reason of
the liquidation or redeployment of deposits or other funds acquired by the
Liquidity Provider to fund or maintain any LIBOR Advance (but excluding loss of
anticipated profits) incurred as a result of:

            (1) Any repayment of a LIBOR Advance on a date other than the last
      day of the Interest Period for such Advance; or

            (2) Any failure by the Borrower to borrow a LIBOR Advance on the
      date for borrowing specified in the relevant notice under Section 2.02.

            Section 3.10. Illegality. Notwithstanding any other provision in
this Agreement, if any change in any applicable law, rule or regulation not
publicly announced on the date hereof shall make it unlawful or impossible for
the Liquidity Provider (or its Lending Office) to maintain or fund its LIBOR
Advances without breaking such law, then upon notice to the Borrower by the
Liquidity Provider, the outstanding principal amount of the LIBOR Advances shall
be converted to Base Rate Advances to the extent necessary to cure such
illegality (a) immediately upon demand of the Liquidity Provider, if such change
or compliance with such request, in the judgment of the Liquidity Provider,
requires immediate repayment; or (b) at the expiration of the last Interest
Period to expire before the effective date of any such change or request. The
Liquidity Provider agrees to use reasonable efforts (consistent with applicable
legal and regulatory restrictions) to change the jurisdiction of its Lending
Office if making such change would avoid or cure the aforesaid illegality.
<PAGE>   21
                                                                              17


                                   ARTICLE IV

                              CONDITIONS PRECEDENT

            Section 4.01. Conditions Precedent to Effectiveness of Section 2.01.
Section 2.01 of this Agreement shall become effective on and as of the first
date (the "Effective Date") on which the following conditions precedent have
been satisfied or waived:

            (a) The Liquidity Provider shall have received on or before the
      Closing Date each of the following, and in the case of each document
      delivered pursuant to paragraphs (i), (ii) and (iii), each in form and
      substance satisfactory to the Liquidity Provider:

                  (i) This Agreement duly executed on behalf of the Borrower;

                  (ii) The Intercreditor Agreement duly executed on behalf of
            each of the parties thereto;

                  (iii) Fully executed copies of each of the Operative
            Agreements executed and delivered on or before the Closing Date
            (other than this Agreement and the Intercreditor Agreement);

                  (iv) A copy of the Offering Memorandum and specimen copies of
            the Class A Certificates;

                  (v) An executed copy of each document, instrument, certificate
            and opinion delivered on or before the Closing Date pursuant to the
            Class A Trust Agreement, the Intercreditor Agreement and the other
            Operative Agreements (in the case of each such opinion, other than
            the opinion of counsel for the Initial Purchasers, either addressed
            to the Liquidity Provider or accompanied by a letter from the
            counsel rendering such opinion to the effect that the Liquidity
            Provider is entitled to rely on such opinion as of its date as if it
            were addressed to the Liquidity Provider);

                  (vi) Evidence that there shall have been made and shall be in
            full force and effect, all filings, recordings and/or registrations,
            and there shall have been given or taken any notice or other similar
            action as are necessary or in order to establish, perfect, protect
            and preserve the right, title and interest of the Liquidity Provider
            created by the Operative Agreements executed and delivered on or
            prior to the Closing Date;

                  (vii) An agreement from America West, pursuant to which
            America West agrees to provide copies of quarterly financial
            statements and audited annual financial statements to the Liquidity
            Provider (which obligations may be satisfied by the furnishing of
            America West's Form 10Q and 10K), in each case, only to the extent
            that America West is obligated to provide such information pursuant
            to Section 8.2.1 of the Leases (related to Leased Aircraft) or the
            corresponding section of the Indentures (related to Owned Aircraft)
            to the parties thereto; and
<PAGE>   22
                                                                              18


                  (viii) Such other documents, instruments, opinions and
            approvals pertaining to the transactions contemplated hereby or by
            the other Operative Agreements as the Liquidity Provider shall have
            reasonably requested.

            (b) The following statement shall be true on and as of the Effective
      Date: no event has occurred and is continuing, or would result from the
      entering into of this Agreement or the making of any Advance, which
      constitutes a Liquidity Event of Default.

            (c) The Liquidity Provider shall have received payment in full of
      all fees and other sums required to be paid to or for account of the
      Liquidity Provider on or prior to the Effective Date.

            (d) All conditions precedent to the issuance of the Certificates
      under the Trust Agreements shall have been satisfied or waived, all
      conditions precedent to the effectiveness of the other Liquidity
      Facilities shall have been satisfied or waived, and all conditions
      precedent to the purchase of the Certificates by the Initial Purchasers
      under the Purchase Agreement shall have been satisfied (unless any of such
      conditions precedent shall have been waived by the Initial Purchasers).

            (e) The Borrower shall have received a certificate, dated the date
      hereof, signed by a duly authorized representative of the Liquidity
      Provider, certifying that all conditions precedent to the effectiveness of
      Section 2.01 have been satisfied or waived.

            Section 4.02. Conditions Precedent to Borrowing. The obligation of
the Liquidity Provider to make an Advance on the occasion of each Borrowing
shall be subject to the conditions precedent that the Effective Date shall have
occurred and, prior to the date of such Borrowing, the Borrower shall have
delivered a Notice of Borrowing which conforms to the terms and conditions of
this Agreement and has been completed as may be required by the relevant form of
the Notice of Borrowing for the type of Advances requested.



                                    ARTICLE V

                                    COVENANTS

            Section 5.01. Affirmative Covenants of the Borrower. So long as any
Advance shall remain unpaid or the Liquidity Provider shall have any Maximum
Commitment hereunder or the Borrower shall have any obligation to pay any amount
to the Liquidity Provider hereunder, the Borrower will, unless the Liquidity
Provider shall otherwise consent in writing:

            (a) Performance of This and Other Agreements. Punctually pay or
      cause to be paid all amounts payable by it under this Agreement and the
      other Operative Agreements and observe and perform in all material
      respects the conditions, covenants and requirements applicable to it
      contained in this Agreement and the other Operative Agreements.
<PAGE>   23
                                                                              19


            (b) Reporting Requirements. Furnish to the Liquidity Provider with
      reasonable promptness, such other information and data with respect to the
      transactions contemplated by the Operative Agreements as from time to time
      may be reasonably requested by the Liquidity Provider; and permit the
      Liquidity Provider, upon reasonable notice, to inspect the Borrower's
      books and records with respect to such transactions and to meet with
      officers and employees of the Borrower to discuss such transactions.

            (c) Certain Operative Agreements. Furnish to the Liquidity Provider
      with reasonable promptness, such Operative Agreements entered into after
      the date hereof as from time to time may be reasonably requested by the
      Liquidity Provider.

            Section 5.02. Negative Covenants of the Borrower. So long as any
Advance shall remain unpaid or the Liquidity Provider shall have any Maximum
Commitment hereunder or the Borrower shall have any obligation to pay any amount
to the Liquidity Provider hereunder, the Borrower will not appoint or permit or
suffer to be appointed any successor Borrower without the prior written consent
of the Liquidity Provider, which consent shall not be unreasonably withheld or
delayed.


                                   ARTICLE VI

                           LIQUIDITY EVENTS OF DEFAULT

            Section 6.01. Liquidity Events of Default. If (a) any Liquidity
Event of Default has occurred and is continuing and (b) there is a Performing
Note Deficiency, the Liquidity Provider may, in its discretion, deliver to the
Borrower a Termination Notice, the effect of which shall be to cause (i) the
obligation of the Liquidity Provider to make Advances hereunder to expire on the
fifth Business Day after the date on which such Termination Notice is received
by the Borrower, (ii) the Borrower to promptly request, and the Liquidity
Provider to promptly make, a Final Advance in accordance with Section 2.02(d)
hereof and Section 3.6(i) of the Intercreditor Agreement, (iii) all other
outstanding Advances to be automatically converted into Final Advances for
purposes of determining the Applicable Liquidity Rate for interest payable
thereon, and (iv) subject to Sections 2.07 and 2.09 hereof, all Advances
(including, without limitation, any Provider Advance and Applied Provider
Advance), any accrued interest thereon and any other amounts outstanding
hereunder to become immediately due and payable to the Liquidity Provider.


                                   ARTICLE VII

                                  MISCELLANEOUS

            Section 7.01. Amendments, Etc. No amendment or waiver of any
provision of this Agreement, nor consent to any departure by the Borrower
therefrom, shall in any event be effective unless the same shall be in writing
and signed by the Liquidity Provider, and, in the case of an amendment or of a
waiver by the Borrower, the Borrower, and then such waiver or consent shall be
effective only in the specific instance and for the specific purpose for which
given.
<PAGE>   24
                                                                              20


            Section 7.02. Notices, Etc. Except as otherwise expressly provided
herein, all notices and other communications provided for hereunder shall be in
writing (including telecopier and mailed or delivered or sent by telecopier):

            Borrower:

            Wilmington Trust Company
            Rodney Square North
            1100 North Market Square
            Wilmington, DE  19890-0001

            Attention: Corporate Trust Administration
            Telephone: 302-651-1000
            Telecopy: 302-651-8882

            Liquidity Provider:

            ABN AMRO BANK N.V.
            135 South LaSalle Street - Suite 660
            Chicago, Illinois 60603

            Attention:  Vice President - Aerospace
            Telephone:  (312) 904-2900
            Telecopy:  (312) 606-8428

            with a copy to:

            ABN AMRO BANK N.V.
            135 South LaSalle Street - Suite 625
            Chicago, Illinois 60603

            Attention:  Loan Administration
            Telephone:  (312) 904-2961
            Telecopy:  (312) 904-1288

or, as to each of the foregoing, at such other address as shall be designated by
such Person in a written notice to the others. All such notices and
communications shall be effective when received unless received outside of
business hours, in which case on the next open of business on a Business Day. A
copy of all notices delivered hereunder to either party shall in addition be
delivered to each of the parties to the Participation Agreements at their
respective addresses set forth therein.

            Section 7.03. No Waiver; Remedies. No failure on the part of the
Liquidity Provider to exercise, and no delay in exercising, any right under this
Agreement shall operate as a waiver thereof; nor shall any single or partial
exercise of any right under this Agreement preclude any other or further
exercise thereof or the exercise of any other right. The remedies herein
provided are cumulative and not exclusive of any remedies provided by law.
<PAGE>   25
                                                                              21


            Section 7.04. Further Assurances. The Borrower agrees to do such
further acts and things and to execute and deliver to the Liquidity Provider
such additional assignments, agreements, powers and instruments as the Liquidity
Provider may reasonably require or deem advisable to carry into effect the
purposes of this Agreement and the other Operative Agreements or to better
assure and confirm unto the Liquidity Provider its rights, powers and remedies
hereunder and under the other Operative Agreements.

            Section 7.05. Indemnification; Survival of Certain Provisions. The
Liquidity Provider shall be indemnified hereunder to the extent and in the
manner described in Section 7.1 or 9.1, as the case may be, of the Participation
Agreements. The indemnities contained in Section 7.1 or 9.1, as the case may be,
of the Participation Agreements, and the provisions of Sections 3.01, 3.02,
3.03, 3.09, 7.05 and 7.07 hereof, shall survive the termination of this
Agreement.

            Section 7.06. Liability of the Liquidity Provider. (a) Neither the
Liquidity Provider nor any of its officers, employees, directors or affiliates
shall be liable or responsible for: (i) the use which may be made of the
Advances or any acts or omissions of the Borrower or any beneficiary or
transferee in connection therewith; or (ii) the validity, sufficiency or
genuineness of documents, or of any endorsement thereon, even if such documents
should prove to be in any or all respects invalid, insufficient, fraudulent or
forged except as executed by the Liquidity Provider; provided, however, that the
Borrower shall have a claim against the Liquidity Provider, and the Liquidity
Provider shall be liable to the Borrower, to the extent of any damages suffered
by the Borrower which were the result of (A) the Liquidity Provider's willful
misconduct or negligence in determining whether documents presented hereunder
comply with the terms hereof, or (B) any breach by the Liquidity Provider of any
of the terms of this Agreement, including, but not limited to, the Liquidity
Provider's failure to make lawful payment hereunder after the delivery to it by
the Borrower of a Notice of Borrowing strictly complying with the terms and
conditions hereof.

            (b) Neither the Liquidity Provider nor any of its officers,
employees, directors or affiliates shall be liable or responsible in any respect
for (i) any error, omission, interruption or delay in transmission, dispatch or
delivery of any message or advice, however transmitted, in connection with this
Agreement or any Notice of Borrowing delivered hereunder, or (ii) any action,
inaction or omission which may be taken by it in good faith, absent willful
misconduct or negligence (in which event the extent of the Liquidity Provider's
potential liability to the Borrower shall be limited as set forth in the
immediately preceding paragraph), in connection with this Agreement or any
Notice of Borrowing.

            Section 7.07. Costs, Expenses and Taxes. The Borrower agrees to pay,
or cause to be paid (A) on the Effective Date and on such later date or dates on
which the Liquidity Provider shall make demand, all reasonable out-of-pocket
costs and expenses (including, without limitation, the reasonable fees and
expenses of outside counsel for the Liquidity Provider) of the Liquidity
Provider in connection with the preparation, negotiation, execution, delivery,
filing and recording of this Agreement, any other Operative Agreement and any
other documents which may be delivered in connection with this Agreement and (B)
on demand, all reasonable costs and expenses (including reasonable counsel fees
and expenses) of the Liquidity Provider in connection with (i) the enforcement
of this Agreement or any other Operative Agreement, (ii) the modification or
amendment of, or supplement to, this Agreement or any other Operative
<PAGE>   26
                                                                              22


Agreement or such other documents which may be delivered in connection herewith
or therewith (whether or not the same shall become effective) other than
amendments requested by the Liquidity Provider or a transfer made by the
Liquidity Provider either voluntarily or as a result of the mitigation
provisions of Article 3 or a Non-Extension Drawing or a Downgrade Drawing or
(iii) any action or proceeding relating to any order, injunction, or other
process or decree restraining or seeking to restrain the Liquidity Provider from
paying any amount under this Agreement, the Intercreditor Agreement or any other
Operative Agreement or otherwise affecting the application of funds in the Class
A Cash Collateral Accounts. In addition, the Borrower shall pay any and all
recording, stamp and other similar taxes and fees payable or determined to be
payable in connection with the execution, delivery, filing and recording of this
Agreement, any other Operative Agreement and such other documents, other than
amendments requested by the Liquidity Provider or a transfer made by the
Liquidity Provider either voluntarily or as a result of the mitigation
provisions of Article 3 or a Non-Extension Drawing or a Downgrade Drawing, and
agrees to save the Liquidity Provider harmless from and against any and all
liabilities with respect to or resulting from any delay in paying or omission to
pay such taxes or fees.

            Section 7.08. Binding Effect; Participations. (a) This Agreement
shall be binding upon and inure to the benefit of the Borrower and the Liquidity
Provider and their respective successors and assigns, except that neither the
Liquidity Provider (except as otherwise provided in this Section 7.08) nor
(except as contemplated by Section 3.08) the Borrower shall have the right to
assign its rights or obligations hereunder or any interest herein without the
prior written consent of the other party, subject to the requirements of Section
7.08(b). The Liquidity Provider may grant participations herein or in any of its
rights hereunder (including, without limitation, funded participations and
participations in rights to receive interest payments hereunder) and under the
other Operative Agreements to such Persons as the Liquidity Provider may in its
sole discretion select, subject to the requirements of Section 7.08(b). No such
participation by the Liquidity Provider, however, will relieve the Liquidity
Provider of its obligations hereunder. In connection with any participation or
any proposed participation, the Liquidity Provider may disclose to the
participant or the proposed participant any information that the Borrower is
required to deliver or to disclose to the Liquidity Provider pursuant to this
Agreement. The Borrower acknowledges and agrees that the Liquidity Provider's
source of funds may derive in part from its participants (other than America
West). Accordingly, references in this Agreement and the other Operative
Agreements to determinations, reserve and capital adequacy requirements,
increased costs, reduced receipts, additional amounts due pursuant to Section
3.03 and the like as they pertain to the Liquidity Provider shall be deemed also
to include those of each of its participants (subject, in each case, to the
maximum amount that would have been incurred by or attributable to the Liquidity
Provider directly if the Liquidity Provider, rather than the participant, had
held the interest participated).

            (b) If, pursuant to subsection (a) above, the Liquidity Provider
sells any participation in this Agreement to any bank or other entity (each, a
"Transferee"), then, concurrently with the effectiveness of such participation,
the Transferee shall (i) represent to the Liquidity Provider (for the benefit of
the Liquidity Provider and the Borrower) either (A) that it is incorporated
under the laws of the United States or a state thereof or (B) that under
applicable law and treaties, no taxes will be required to be withheld with
respect to any payments to be made to such Transferee in respect of this
Agreement, (ii) furnish to the Liquidity Provider and the Borrower either (x) a
statement that it is incorporated under the laws of the United States or a 
<PAGE>   27
                                                                              23


state thereof or (y) if it is not so incorporated, two copies of a properly
completed United States Internal Revenue Service Form 4224 or Form 1001, as
appropriate, or other applicable form, certificate or document prescribed by the
Internal Revenue Service certifying, in each case, such Transferee's entitlement
to a complete exemption from United States federal withholding tax in respect to
any and all payments to be made hereunder, and (iii) agree (for the benefit of
the Liquidity Provider and the Borrower) to provide the Liquidity Provider and
the Borrower a new Form 4224 or Form 1001, as appropriate, (A) on or before the
date that any such form expires or becomes obsolete or (B) after the occurrence
of any event requiring a change in the most recent form previously delivered by
it and prior to the immediately following due date of any payment by the
Borrower hereunder, certifying in the case of a Form 1001 or Form 4224 that such
Transferee is entitled to a complete exemption from United States federal
withholding tax on payments under this Agreement. Unless the Borrower has
received forms or other documents reasonably satisfactory to it (and required by
applicable law) indicating that payments hereunder are not subject to United
States federal withholding tax, the Borrower will withhold taxes as required by
law from such payments at the applicable statutory rate.

            (c) Notwithstanding the other provisions of this Section 7.08, the
Liquidity Provider may assign and pledge all or any portion of the Advances
owing to it to any Federal Reserve Bank or the United States Treasury as
collateral security pursuant to Regulation A of the Board of Governors of the
Federal Reserve System and any Operating Circular issued by such Federal Reserve
Bank, provided that any payment in respect of such assigned Advances made by the
Borrower to the Liquidity Provider in accordance with the terms of this
Agreement shall satisfy the Borrower's obligations hereunder in respect of such
assigned Advance to the extent of such payment. No such assignment shall release
the Liquidity Provider from its obligations hereunder.

            Section 7.09. Severability. Any provision of this Agreement which is
prohibited, unenforceable or not authorized in any jurisdiction shall, as to
such jurisdiction, be ineffective to the extent of such prohibition,
unenforceability or non-authorization without invalidating the remaining
provisions hereof or affecting the validity, enforceability or legality of such
provision in any other jurisdiction.

            Section 7.10. GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY,
AND CONSTRUED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.

            Section 7.11. Submission to Jurisdiction; Waiver of Jury Trial;
Waiver of Immunity. (a) Each of the parties hereto hereby irrevocably and
unconditionally:

            (i) submits for itself and its property in any legal action or
      proceeding relating to this Agreement or any other Operative Agreement, or
      for recognition and enforcement of any judgment in respect hereof or
      thereof, to the nonexclusive general jurisdiction of the courts of the
      State of New York, the courts of the United States of America for the
      Southern District of New York, and the appellate courts from any thereof;

            (ii) consents that any such action or proceeding may be brought in
      such courts, and waives any objection that it may now or hereafter have to
      the venue of any 
<PAGE>   28
                                                                              24


      such action or proceeding in any such court or that such action or
      proceeding was brought in an inconvenient court and agrees not to plead or
      claim the same;

            (iii) agrees that service of process in any such action or
      proceeding may be effected by mailing a copy thereof by registered or
      certified mail (or any substantially similar form and mail), postage
      prepaid, to each party hereto at its address set forth in Section 7.02
      hereof, or at such other address of which the Liquidity Provider shall
      have been notified pursuant thereto; and

            (iv) agrees that nothing herein shall affect the right to effect
      service of process in any other manner permitted by law or shall limit the
      right to sue in any other jurisdiction.

            (b) THE BORROWER AND THE LIQUIDITY PROVIDER EACH HEREBY AGREE TO
WAIVE THEIR RESPECTIVE RIGHTS TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION
BASED UPON OR ARISING OUT OF THIS AGREEMENT OR ANY DEALINGS BETWEEN THEM
RELATING TO THE SUBJECT MATTER OF THIS AGREEMENT AND THE RELATIONSHIP THAT IS
BEING ESTABLISHED, including, without limitation, contract claims, tort claims,
breach of duty claims and all other common law and statutory claims. The
Borrower and the Liquidity Provider each warrant and represent that it has
reviewed this waiver with its legal counsel, and that it knowingly and
voluntarily waives its jury trial rights following consultation with such legal
counsel. THIS WAIVER IS IRREVOCABLE, AND CANNOT BE MODIFIED EITHER ORALLY OR IN
WRITING, AND THIS WAIVER SHALL APPLY TO ANY SUBSEQUENT AMENDMENTS, RENEWALS,
SUPPLEMENTS OR MODIFICATIONS TO THIS AGREEMENT.

            (c) The Liquidity Provider hereby waives any immunity it may have
from the jurisdiction of the courts of the United States or of any State and
waives any immunity any of its properties located in the United States may have
from attachment or execution upon a judgment entered by any such court under the
United States Foreign Sovereign Immunities Act of 1976 or any similar successor
legislation.

            Section 7.12. Execution in Counterparts. This Agreement may be
executed in any number of counterparts and by different parties hereto on
separate counterparts, each of which counterparts, when so executed and
delivered, shall be deemed to be an original and all of which counterparts,
taken together, shall constitute but one and the same Agreement.

            Section 7.13. Entirety. This Agreement, the Intercreditor Agreement
and the other Operative Agreements to which the Liquidity Provider is a party
constitute the entire agreement of the parties hereto with respect to the
subject matter hereof and supersedes all prior understandings and agreements of
such parties.

            Section 7.14. Headings. Section headings in this Agreement are
included herein for convenience of reference only and shall not constitute a
part of this Agreement for any other purpose.
<PAGE>   29
                                                                              25


            Section 7.15. Transfer. The Liquidity Provider hereby acknowledges
and consents to the Transfer contemplated by the Assignment and Assumption
Agreement.

            Section 7.16. LIQUIDITY PROVIDER'S OBLIGATION TO MAKE ADVANCES.
EXCEPT AS EXPRESSLY SET FORTH IN THIS AGREEMENT, THE OBLIGATIONS OF THE
LIQUIDITY PROVIDER TO MAKE ADVANCES HEREUNDER, AND THE BORROWER'S RIGHTS TO
DELIVER NOTICES OF BORROWING REQUESTING THE MAKING OF ADVANCES HEREUNDER, SHALL
BE UNCONDITIONAL AND IRREVOCABLE, AND SHALL BE PAID OR PERFORMED, IN EACH CASE
STRICTLY IN ACCORDANCE WITH THE TERMS OF THIS AGREEMENT.
<PAGE>   30
            IN WITNESS WHEREOF, the parties have caused this Agreement to be
duly executed and delivered by their respective officers thereunto duly
authorized as of the date first set forth above.

                                    WILMINGTON TRUST COMPANY,
                                      not in its individual capacity but solely
                                      as Subordination Agent, as agent and
                                      trustee for the Class A Trust, as Borrower



                                    By:  /s/ Jill K. Morrison
                                       ------------------------------------
                                       Name:  Jill K. Morrison
                                       Title: Administrative Account Manager


                                    ABN AMRO BANK N.V., Chicago Branch
                                    as Liquidity Provider



                                    By:  /s/ Claudia C. Heldring
                                       ------------------------------------
                                       Name:  Claudia C. Heldring
                                       Title: Vice President



                                    By:  /s/ Carla S. Waggoner
                                       ------------------------------------
                                       Name:  Carla S. Waggoner
                                       Title: Assistant Vice President


<PAGE>   31
                                                                      Annex I to
                                                      Revolving Credit Agreement


                      INTEREST ADVANCE NOTICE OF BORROWING

            The undersigned, a duly authorized signatory of the undersigned
borrower (the "Borrower"), hereby certifies to ABN AMRO BANK, N.V., Chicago
Branch (the "Liquidity Provider"), with reference to the Revolving Credit
Agreement (1998-1A) dated as of October 6, 1998, between the Borrower and the
Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and not
otherwise defined herein being used herein as therein defined or referenced),
that:

            (1) The Borrower is the Subordination Agent under the Intercreditor
      Agreement.

            (2) The Borrower is delivering this Notice of Borrowing for the
      making of an Interest Advance by the Liquidity Provider to be used,
      subject to clause (3)(v) below, for the payment of interest on the Class A
      Certificates which was payable on ____________, ____ (the "Distribution
      Date") in accordance with the terms and provisions of the Class A Trust
      Agreement and the Class A Certificates, which Advance is requested to be
      made on the date hereof.

            (3) The amount of the Interest Advance requested hereby (i) is
      $_______________.__, to be applied in respect of the payment of the
      interest which was due and payable on the Class A Certificates on the
      Distribution Date, (ii) does not include any amount with respect to the
      payment of principal of, or premium on, the Class A Certificates, the
      Class B Certificates or the Class C Certificates, or interest on the Class
      B Certificates or the Class C Certificates, (iii) was computed in
      accordance with the provisions of the Class A Certificates, the Class A
      Trust Agreement and the Intercreditor Agreement (a copy of which
      computation is attached hereto as Schedule I), (iv) does not exceed the
      Maximum Available Commitment on the date hereof, (v) does not include any
      amount of interest which was due and payable on the Class A Certificates
      on such Distribution Date but which remains unpaid due to the failure of
      the Depositary to pay any amount of accrued interest on the Deposits on
      such Distribution Date and (vi) has not been and is not the subject of a
      prior or contemporaneous Notice of Borrowing.

            (4) Upon receipt by or on behalf of the Borrower of the amount
      requested hereby, (a) the Borrower will apply the same in accordance with
      the terms of Section 3.6(b) of the Intercreditor Agreement, (b) no portion
      of such amount shall be applied by the Borrower for any other purpose and
      (c) no portion of such amount until so applied shall be commingled with
      other funds held by the Borrower.

            The Borrower hereby acknowledges that, pursuant to the Liquidity
Agreement, the making of the Interest Advance as requested by this Notice of
Borrowing shall automatically reduce, subject to reinstatement in accordance
with the terms of the Liquidity Agreement, the Maximum Available Commitment by
an amount equal to the amount of the Interest Advance 


                                       I-1
<PAGE>   32
requested to be made hereby as set forth in clause (i) of paragraph (3) of this
Certificate and such reduction shall automatically result in corresponding
reductions in the amounts available to be borrowed pursuant to a subsequent
Advance.

            IN WITNESS WHEREOF, the Borrower has executed and delivered this
Notice of Borrowing as of the ____ day of _________, ____.


                                    WILMINGTON TRUST COMPANY,
                                       not in its individual capacity but solely
                                       as Subordination Agent, as Borrower


                                    By:_________________________________
                                       Name:
                                       Title:


                                       I-2
<PAGE>   33
               SCHEDULE I TO INTEREST ADVANCE NOTICE OF BORROWING

[Insert Copy of Computations in accordance with Interest Advance Notice of
Borrowing]


                                       I-2
<PAGE>   34
                                                                     Annex II to
                                                      Revolving Credit Agreement

                    NON-EXTENSION ADVANCE NOTICE OF BORROWING

            The undersigned, a duly authorized signatory of the undersigned
subordination agent (the "Borrower"), hereby certifies to ABN AMRO BANK N.V.,
Chicago Branch (the "Liquidity Provider"), with reference to the Revolving
Credit Agreement (1998-1A) dated as of October 6, 1998, between the Borrower and
the Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and
not otherwise defined herein being used herein as therein defined or
referenced), that:

            (1) The Borrower is the Subordination Agent under the Intercreditor
      Agreement.

            (2) The Borrower is delivering this Notice of Borrowing for the
      making of the Non-Extension Advance by the Liquidity Provider to be used
      for the funding of the Class A Cash Collateral Account in accordance with
      Section 3.6(d) of the Intercreditor Agreement, which Advance is requested
      to be made on __________, ____.

            (3) The amount of the Non-Extension Advance requested hereby (i) is
      $______________, which equals the Maximum Available Commitment on the date
      hereof and is to be applied in respect of the funding of the Class A Cash
      Collateral Account in accordance with Section 3.6(d) of the Intercreditor
      Agreement, (ii) does not include any amount with respect to the payment of
      the principal of, or premium on, the Class A Certificates, or principal
      of, or interest or premium on, the Class B Certificates or the Class C
      Certificates, (iii) was computed in accordance with the provisions of the
      Class A Certificates, the Class A Trust Agreement and the Intercreditor
      Agreement (a copy of which computation is attached hereto as Schedule I),
      and (iv) has not been and is not the subject of a prior or contemporaneous
      Notice of Borrowing under the Liquidity Agreement.

            (4) Upon receipt by or on behalf of the Borrower of the amount
      requested hereby, (a) the Borrower will deposit such amount in the Class A
      Cash Collateral Account and apply the same in accordance with the terms of
      Section 3.6(d) of the Intercreditor Agreement, (b) no portion of such
      amount shall be applied by the Borrower for any other purpose and (c) no
      portion of such amount until so applied shall be commingled with other
      funds held by the Borrower.

            The Borrower hereby acknowledges that, pursuant to the Liquidity
Agreement, (A) the making of the Non-Extension Advance as requested by this
Notice of Borrowing shall automatically and irrevocably terminate the obligation
of the Liquidity Provider to make further Advances under the Liquidity
Agreement; and (B) following the making by the Liquidity Provider of the
Non-Extension Advance requested by this Notice of Borrowing, the Borrower shall
not be entitled to request any further Advances under the Liquidity Agreement.


                                      II-1
<PAGE>   35
            IN WITNESS WHEREOF, the Borrower has executed and delivered this
Notice of Borrowing as of the ____ day of _________, ____.

                                    WILMINGTON TRUST COMPANY,
                                       not in its individual capacity but solely
                                       as Subordination Agent, as Borrower

                                    By:_________________________________
                                       Name:
                                       Title:


                                      II-2
<PAGE>   36
           SCHEDULE I TO NON-EXTENSION ADVANCE NOTICE OF BORROWING

[Insert Copy of computations in accordance with Non-Extension Advance Notice
of Borrowing]


                                      II-2
<PAGE>   37
                                                                    Annex III to
                                                      Revolving Credit Agreement

                      DOWNGRADE ADVANCE NOTICE OF BORROWING

            The undersigned, a duly authorized signatory of the undersigned
subordination agent (the "Borrower"), hereby certifies to ABN AMRO BANK N.V.,
Chicago Branch (the "Liquidity Provider"), with reference to the Revolving
Credit Agreement (1998-1A) dated as of October 6, 1998, between the Borrower and
the Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and
not otherwise defined herein being used herein as therein defined or
referenced), that:

            (1) The Borrower is the Subordination Agent under the Intercreditor
      Agreement.

            (2) The Borrower is delivering this Notice of Borrowing for the
      making of the Downgrade Advance by the Liquidity Provider to be used for
      the funding of the Class A Cash Collateral Account in accordance with
      Section 3.6(c) of the Intercreditor Agreement by reason of the downgrading
      of the short-term unsecured debt rating of the Liquidity Provider issued
      by either Rating Agency below the Threshold Rating, which Advance is
      requested to be made on __________, ____.

            (3) The amount of the Downgrade Advance requested hereby (i) is
      $________________, which equals the Maximum Available Commitment on the
      date hereof and is to be applied in respect of the funding of the Class A
      Cash Collateral Account in accordance with Section 3.6(c) of the
      Intercreditor Agreement, (ii) does not include any amount with respect to
      the payment of the principal of, or premium on, the Class A Certificates,
      or principal of, or interest or premium on, the Class B Certificates or
      the Class C Certificates, (iii) was computed in accordance with the
      provisions of the Class A Certificates, the Class A Trust Agreement and
      the Intercreditor Agreement (a copy of which computation is attached
      hereto as Schedule I), and (iv) has not been and is not the subject of a
      prior or contemporaneous Notice of Borrowing under the Liquidity
      Agreement.

            (4) Upon receipt by or on behalf of the Borrower of the amount
      requested hereby, (a) the Borrower will deposit such amount in the Class A
      Cash Collateral Account and apply the same in accordance with the terms of
      Section 3.6(c) of the Intercreditor Agreement, (b) no portion of such
      amount shall be applied by the Borrower for any other purpose and (c) no
      portion of such amount until so applied shall be commingled with other
      funds held by the Borrower.

            The Borrower hereby acknowledges that, pursuant to the Liquidity
Agreement, (A) the making of the Downgrade Advance as requested by this Notice
of Borrowing shall automatically and irrevocably terminate the obligation of the
Liquidity Provider to make further Advances under the Liquidity Agreement; and
(B) following the making by the Liquidity 
<PAGE>   38
Provider of the Downgrade Advance requested by this Notice of Borrowing, the
Borrower shall not be entitled to request any further Advances under the
Liquidity Agreement.

            IN WITNESS WHEREOF, the Borrower has executed and delivered this
Notice of Borrowing as of the ____ day of _________, ____.

                                    WILMINGTON TRUST COMPANY,
                                       not in its individual capacity but solely
                                       as Subordination Agent, as Borrower


                                    By:_________________________________
                                       Name:
                                       Title:
<PAGE>   39
             SCHEDULE I TO DOWNGRADE ADVANCE NOTICE OF BORROWING

[Insert Copy of computations in accordance with Downgrade Advance Notice of
Borrowing]
<PAGE>   40
                                                                     Annex IV to
                                                      Revolving Credit Agreement

                        FINAL ADVANCE NOTICE OF BORROWING

            The undersigned, a duly authorized signatory of the undersigned
borrower (the "Borrower"), hereby certifies to ABN AMRO BANK N.V., Chicago
Branch (the "Liquidity Provider"), with reference to the Revolving Credit
Agreement (1998-1A) dated as of October 6, 1998, between the Borrower and the
Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and not
otherwise defined herein being used herein as therein defined or referenced),
that:

            (1) The Borrower is the Subordination Agent under the Intercreditor
      Agreement.

            (2) The Borrower is delivering this Notice of Borrowing for the
      making of the Final Advance by the Liquidity Provider to be used for the
      funding of the Class A Cash Collateral Account in accordance with Section
      3.6(i) of the Intercreditor Agreement by reason of the receipt by the
      Borrower of a Termination Notice from the Liquidity Provider with respect
      to the Liquidity Agreement, which Advance is requested to be made on
      ____________, ____.

            (3) The amount of the Final Advance requested hereby (i) is
      $_________________, which equals the Maximum Available Commitment on the
      date hereof and is to be applied in respect of the funding of the Class A
      Cash Collateral Account in accordance with Section 3.6(i) of the
      Intercreditor Agreement, (ii) does not include any amount with respect to
      the payment of principal of, or premium on, the Class A Certificates, or
      principal of, or interest or premium on, the Class B Certificates or the
      Class C Certificates, (iii) was computed in accordance with the provisions
      of the Class A Certificates, the Class A Trust Agreement and the
      Intercreditor Agreement (a copy of which computation is attached hereto as
      Schedule I), and (iv) has not been and is not the subject of a prior or
      contemporaneous Notice of Borrowing.

            (4) Upon receipt by or on behalf of the Borrower of the amount
      requested hereby, (a) the Borrower will deposit such amount in the Class A
      Cash Collateral Account and apply the same in accordance with the terms of
      Section 3.6(i) of the Intercreditor Agreement, (b) no portion of such
      amount shall be applied by the Borrower for any other purpose and (c) no
      portion of such amount until so applied shall be commingled with other
      funds held by the Borrower.

            The Borrower hereby acknowledges that, pursuant to the Liquidity
Agreement, (A) the making of the Final Advance as requested by this Notice of
Borrowing shall automatically and irrevocably terminate the obligation of the
Liquidity Provider to make further Advances under the Liquidity Agreement; and
(B) following the making by the Liquidity Provider of the Final Advance
requested by this Notice of Borrowing, the Borrower shall not be entitled to
request any further Advances under the Liquidity Agreement.


                                      IV-1
<PAGE>   41
            IN WITNESS WHEREOF, the Borrower has executed and delivered this
Notice of Borrowing as of the ____ day of _________, ____.

                                    WILMINGTON TRUST COMPANY,
                                       not in its individual capacity but solely
                                       as Subordination Agent, as Borrower

                                    By:_________________________________
                                       Name:
                                       Title:
<PAGE>   42
                 SCHEDULE I TO FINAL ADVANCE NOTICE OF BORROWING

[Insert Copy of Computations in accordance with Final Advance Notice of
Borrowing]
<PAGE>   43
                                                                      Annex V to
                                                      Revolving Credit Agreement


                              NOTICE OF TERMINATION


                                     [Date]



Wilmington Trust Company,
  as Subordination Agent, as Borrower
Rodney Square North
1100 North Market Square
Wilmington, DE  19890-0001


Re:   Revolving Credit Agreement dated as of October 6, 1998, between
      Wilmington Trust Company, as Subordination Agent, as agent and
      trustee for the America West Airlines Pass Through Trust,
      1998-1A-[O/S], as Borrower, and ABN AMRO Bank N.V., Chicago
      Branch, as the Liquidity Provider (the "Liquidity Agreement")


Ladies and Gentlemen:

            You are hereby notified that pursuant to Section 6.01 of the
Liquidity Agreement, by reason of the occurrence of a Liquidity Event of Default
and the existence of a Performing Note Deficiency (each as defined therein), we
are giving this notice to you in order to cause (i) our obligations to make
Advances (as defined therein) under such Liquidity Agreement to terminate on the
fifth Business Day after the date on which you receive this notice and (ii) you
to request a Final Advance under the Liquidity Agreement pursuant to Section
3.6(i) of the Intercreditor Agreement (as defined in the Liquidity Agreement) as
a consequence of your receipt of this notice.


                                       V-1
<PAGE>   44
            THIS NOTICE IS THE "NOTICE OF TERMINATION" PROVIDED FOR UNDER THE
LIQUIDITY AGREEMENT.  OUR OBLIGATIONS TO MAKE ADVANCES UNDER THE LIQUIDITY
AGREEMENT WILL TERMINATE ON THE FIFTH BUSINESS DAY AFTER THE DATE ON WHICH
YOU RECEIVE THIS NOTICE.

                                    Very truly yours,

                                    ABN AMRO BANK N.V., Chicago Branch
                                      as Liquidity Provider

                                    By:_________________________________
                                       Name:
                                       Title:


                                    By:_________________________________
                                       Name:
                                       Title:
cc: WILMINGTON TRUST COMPANY,
      as Class A Trustee


                                       V-2
<PAGE>   45
                                                                     Annex VI to
                                                      Revolving Credit Agreement

                    NOTICE OF REPLACEMENT SUBORDINATION AGENT

[Date]
Attention:

      Revolving Credit Agreement dated as of October 6, 1998, between WILMINGTON
      TRUST COMPANY, as Subordination Agent, as agent and trustee for the
      America West Airlines Pass Through Trust, 1998-1A-[O/S], as Borrower, and
      ABN AMRO Bank N.V., Chicago Branch, as the Liquidity Provider (the
      "Liquidity Agreement")


Ladies and Gentlemen:

            For value received, the undersigned beneficiary hereby irrevocably
transfers to:

                          ____________________________
                              [Name of Transferee]


                          ____________________________
                             [Address of Transferee]

all rights and obligations of the undersigned as Borrower under the Liquidity
Agreement referred to above. The transferee has succeeded the undersigned as
Subordination Agent under the Intercreditor Agreement referred to in the first
paragraph of the Liquidity Agreement, pursuant to the terms of Section 8.1 of
the Intercreditor Agreement.

            By this transfer, all rights of the undersigned as Borrower under
the Liquidity Agreement are transferred to the transferee and the transferee
shall hereafter have the sole rights and obligations as Borrower thereunder. The
undersigned shall pay any costs and expenses of such transfer, including, but
not limited to, transfer taxes or governmental charges.


                                      VI-1
<PAGE>   46
            We ask that this transfer be effective as of _______________, ____.

                                    WILMINGTON TRUST COMPANY,
                                       not in its individual capacity but solely
                                       as Subordination Agent, as Borrower

                                    By:_________________________________
                                       Name:
                                       Title:


                                      VI-2

<PAGE>   1
                                                                       EXECUTION



                                                                    Exhibit 4.11


        -----------------------------------------------------------------

                           REVOLVING CREDIT AGREEMENT
                                    (1998-1B)


                           Dated as of October 6, 1998

                                     between

                            WILMINGTON TRUST COMPANY,

                    not in its individual capacity but solely
                             as Subordination Agent,
                          as agent and trustee for the
                America West Airlines Pass Through Trust 1998-1B

                                   as Borrower

                                       and

                       ABN AMRO BANK N.V., CHICAGO BRANCH

                              as Liquidity Provider

        -----------------------------------------------------------------


                                   Relating to

                America West Airlines Pass Through Trust 1998-1B
             7.12% America West Airlines Pass Through Certificates,
                                 Series 1998-1B
<PAGE>   2
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                               Page
                                                                                                               ----
<S>                 <C>                                                                                        <C>
                              ARTICLE I DEFINITIONS
     Section 1.01.  Certain Defined Terms. .......................................................................1

                      ARTICLE II AMOUNT AND TERMS OF THE COMMITMENT
     Section 2.01.  The Advances. ................................................................................7
     Section 2.02.  Making the Advances. .........................................................................7
     Section 2.03.  Fees. ........................................................................................8
     Section 2.04.  Reduction or Termination of the Maximum Commitment. ..........................................8
     Section 2.05.  Repayments of Interest Advances or the Final Advance. ........................................9
     Section 2.06.  Repayments of Provider Advances. .............................................................9
     Section 2.07.  Payments to the Liquidity Provider Under the Intercreditor Agreement. .......................10
     Section 2.08.  Book Entries. ...............................................................................10
     Section 2.09.  Payments from Available Funds Only. .........................................................11
     Section 2.10.  Extension of the Expiry Date; Non-Extension Advance. ........................................11

                     ARTICLE III OBLIGATIONS OF THE BORROWER
     Section 3.01.  Increased Costs. ............................................................................12
     Section 3.02.  Capital Adequacy. ...........................................................................13
     Section 3.03.  Payments Free of Deductions. ................................................................14
     Section 3.04.  Payments. ...................................................................................14
     Section 3.05.  Computations. ...............................................................................14
     Section 3.06.  Payment on Non-Business Days. ...............................................................15
     Section 3.07.  Interest. ...................................................................................15
     Section 3.08.  Replacement of Borrower. ....................................................................16
     Section 3.09.  Funding Loss Indemnification. ...............................................................16
     Section 3.10.  Illegality. .................................................................................16

                         ARTICLE IV CONDITIONS PRECEDENT
     Section 4.01.  Conditions Precedent to Effectiveness of Section 2.01. ......................................17
     Section 4.02.  Conditions Precedent to Borrowing. ..........................................................18

                               ARTICLE V COVENANTS
     Section 5.01.  Affirmative Covenants of the Borrower. ......................................................18
     Section 5.02.  Negative Covenants of the Borrower. .........................................................19

                     ARTICLE VI LIQUIDITY EVENTS OF DEFAULT
     Section 6.01.  Liquidity Events of Default. ................................................................19

                            ARTICLE VII MISCELLANEOUS
     Section 7.01.  Amendments, Etc. ............................................................................19
     Section 7.02.  Notices, Etc. ...............................................................................20
     Section 7.03.  No Waiver; Remedies. ........................................................................20
     Section 7.04.  Further Assurances. .........................................................................21
     Section 7.05.  Indemnification; Survival of Certain Provisions. ............................................21
     Section 7.06.  Liability of the Liquidity Provider. ........................................................21
</TABLE>
                                       i
<PAGE>   3
                                TABLE OF CONTENTS
                                  (CONTINUED)

<TABLE>
<CAPTION>
<S>                 <C>                                                                                        <C>
     Section 7.07.  Costs, Expenses and Taxes. ..................................................................21
     Section 7.08.  Binding Effect; Participations. .............................................................22
     Section 7.09.  Severability. ...............................................................................23
     Section 7.10.  Governing Law. ..............................................................................23
     Section 7.11.  Submission to Jurisdiction; Waiver of Jury Trial; Waiver of Immunity. .......................23
     Section 7.12.  Execution in Counterparts. ..................................................................24
     Section 7.13.  Entirety. ...................................................................................24
     Section 7.14.  Headings. ...................................................................................24
     Section 7.15.  Transfer. ...................................................................................25
     Section 7.16.  Liquidity Provider's Obligation To Make Advances. ...........................................25
</TABLE>

                                       ii
<PAGE>   4
                                TABLE OF CONTENTS
                                   (CONTINUED)


ANNEX I                  Interest Advance Notice of Borrowing

ANNEX II                 Non-Extension Advance Notice of Borrowing

ANNEX III                Downgrade Advance Notice of Borrowing

ANNEX IV                 Final Advance Notice of Borrowing

ANNEX V                  Notice of Termination

ANNEX VI                 Notice of Replacement Subordination Agent

                                      iii
<PAGE>   5
                           REVOLVING CREDIT AGREEMENT

                  This REVOLVING CREDIT AGREEMENT dated as of October 6, 1998,
between WILMINGTON TRUST COMPANY, a Delaware banking corporation, not in its
individual capacity but solely as Subordination Agent under the Intercreditor
Agreement (each as defined below), as agent and trustee for the Class B Trust
(as defined below) (the "Borrower"), and ABN AMRO BANK N.V., a bank organized
under the laws of the Netherlands, acting through its Chicago branch (the
"Liquidity Provider").

                              W I T N E S S E T H:

                  WHEREAS, pursuant to the Class B Trust Agreement (such term
and all other capitalized terms used in these recitals having the meanings set
forth or referred to in Section 1.01), the Class B Trust is issuing the Class B
Certificates; and

                  WHEREAS, the Borrower, in order to support the timely payment
of a portion of the interest on the Class B Certificates in accordance with
their terms, has requested the Liquidity Provider to enter into this Agreement,
providing in part for the Borrower to request in specified circumstances that
Advances be made hereunder.

                  NOW, THEREFORE, in consideration of the premises, the parties
hereto agree as follows:


                                    ARTICLE I

                                   DEFINITIONS

                  Section 1.01. Certain Defined Terms. (a) Definitions. As used
in this Agreement and unless otherwise expressly indicated, or unless the
context clearly requires otherwise, the following capitalized terms shall have
the following respective meanings for all purposes of this Agreement:

                  "Additional Cost" has the meaning assigned to such term in
         Section 3.01.

                  "Advance" means an Interest Advance, a Final Advance, a
         Provider Advance, an Applied Provider Advance or an Unpaid Advance, as
         the case may be.

                  "Applicable Liquidity Rate" has the meaning assigned to such
         term in Section 3.07(g).

                  "Applicable Margin" means (A) with respect to any Unpaid
         Advance or Applied Provider Advance, (x) with respect to any LIBOR
         Advance, 1.75% and (y) with respect to any Base Rate Advance, 1%, and
         (B) with respect to any Unapplied Provider Advance, (x) with respect to
         any LIBOR Advance, .35% and (y) with respect to any Base Rate Advance,
         0.
<PAGE>   6
                                                                               2

                  "Applied Downgrade Advance" has the meaning assigned to such
         term in Section 2.06(a).

                  "Applied Non-Extension Advance" has the meaning assigned to
         such term in Section 2.06(a).

                  "Applied Provider Advance" has the meaning assigned to such
         term in Section 2.06(a).

                  "Assignment and Assumption Agreement" means the Assignment and
         Assumption to be entered into between the Borrower and the trustee of
         the Successor Trust, substantially in the form of Exhibit D to the
         Class B Trust Agreement.

                  "Base Rate" means a fluctuating interest rate per annum in
         effect from time to time, which rate per annum shall at all times be
         equal to (a) the weighted average of the rates on overnight Federal
         funds transactions with members of the Federal Reserve System arranged
         by Federal funds brokers, as published for such day (or, if such day is
         not a Business Day, for the next preceding Business Day) by the Federal
         Reserve Bank of New York, or if such rate is not so published for any
         day that is a Business Day, the average of the quotations for such day
         for such transactions received by the Liquidity Provider from three
         Federal funds brokers of recognized standing selected by it, plus (b)
         one quarter of one percent (1/4 of 1%).

                  "Base Rate Advance" means an Advance that bears interest at a
         rate based upon the Base Rate.

                  "Borrower" has the meaning assigned to such term in the
         recital of parties to this Agreement.

                  "Borrowing" means the making of Advances requested by delivery
         of a Notice of Borrowing.

                  "Business Day" means any day other than a Saturday or Sunday
         or a day on which commercial banks are required or authorized to close
         in Phoenix, Arizona, New York, New York, Chicago, Illinois or, so long
         as any Class B Certificate is outstanding, the city and state in which
         the Class B Trustee, the Borrower or any Loan Trustee maintains its
         Corporate Trust Office or receives or disburses funds, and, if the
         applicable Business Day relates to any Advance or other amount bearing
         interest based on the LIBOR Rate, on which dealings are carried on in
         the London interbank market.

                  "Deposits" has the meaning assigned to such terms in the
         Deposit Agreement.

                  "Depositary" has the meaning assigned to such term in the
         Deposit Agreement.

                  "Deposit Agreement" means the Deposit Agreement dated October
         6, 1998 between Wilmington Trust Company, as Escrow Agent and ABN AMRO
         Bank N.V., acting through its Chicago branch, as Depositary, pertaining
         to the Class B Certificates,
<PAGE>   7
                                                                               3

         as the same may be amended, modified or supplemented from time to time
         in accordance with the terms thereof.

                  "Downgrade Advance" means an advance made pursuant to Section
         2.02(c).

                  "Effective Date" has the meaning specified in Section 4.01.
         The delivery of the certificate of the Liquidity Provider contemplated
         by Section 4.01(e) shall be conclusive evidence that the Effective Date
         has occurred.

                  "Excluded Taxes" means (i) taxes imposed on the overall net
         income, net worth, capital or franchise of the Liquidity Provider or of
         its Lending Office by the jurisdiction where such Liquidity Provider's
         principal office or such Lending Office is located, and (ii) Excluded
         Withholding Taxes.

                  "Excluded Withholding Taxes" means (i) withholding Taxes
         imposed by the United States except (but only in the case of a
         successor Liquidity Provider organized under the laws of a jurisdiction
         outside the United States) to the extent that such United States
         withholding Taxes are imposed as a result of any change in applicable
         law (excluding from change in applicable law for this purpose a change
         in an applicable treaty or other change in law affecting the
         applicability of a treaty) after the date hereof, or in the case of a
         successor Liquidity Provider (including a transferee of an Advance) or
         Lending Office, after the date on which such successor Liquidity
         Provider obtains its interest or on which the Lending Office is
         changed, and (ii) any withholding Taxes imposed by the United States
         which are imposed or increased as a result of the Liquidity Provider
         failing to deliver to the Borrower any certificate or document (which
         certificate or document in the good faith judgment of the Liquidity
         Provider it is legally entitled to provide) which is reasonably
         requested by the Borrower to establish that payments under this
         Agreement are exempt from (or entitled to a reduced rate of)
         withholding Tax.

                  "Expenses" means liabilities, obligations, damages,
         settlements, penalties, claims, actions, suits, costs, expenses, and
         disbursements (including, without limitation, reasonable fees and
         disbursements of legal counsel and costs of investigation), provided
         that Expenses shall not include any Taxes.

                  "Expiry Date" means October 4, 1999, initially, or any date to
         which the Expiry Date is extended pursuant to Section 2.10.

                  "Final Advance" means an advance made pursuant to Section
         2.02(d).

                  "Intercreditor Agreement" means the Intercreditor Agreement
         dated the date hereof, among the Trustees, the Liquidity Provider, the
         liquidity provider under each Liquidity Facility (other than this
         Agreement) and the Subordination Agent, as the same may be amended,
         supplemented or otherwise modified from time to time in accordance with
         its terms.

                  "Interest Advance" means an advance made pursuant to Section
         2.02(a).
<PAGE>   8
                                                                               4

                  "Interest Period" means, with respect to any LIBOR Advance,
each of the following periods:

                  (i)      the period beginning on the third Business Day
                           following either (x) the Liquidity Provider's receipt
                           of the Notice of Borrowing for such LIBOR Advance
                           (or, in the case of an Unapplied Downgrade Advance,
                           the period beginning on the Expiry Date) or (y) the
                           withdrawal of funds from the Class B Cash Collateral
                           Account for the purpose of paying interest on the
                           Class B Certificates as contemplated by Section
                           2.06(a) hereof and, in either case, ending on the
                           next Regular Distribution Date; and

                  (ii)     each subsequent period commencing on the last day of
                           the immediately preceding Interest Period and ending
                           on the next Regular Distribution Date;

         provided, however, that if (x) the Final Advance shall have been made,
         or (y) other outstanding Advances shall have been converted into the
         Final Advance, then the Interest Periods shall be successive periods of
         one month beginning on the third Business Day following the Liquidity
         Provider's receipt of the Notice of Borrowing for such Final Advance
         (in the case of clause (x) above) or the last day of the Interest
         Period then applicable to such outstanding Advances (in the case of
         clause (y) above).

                  "Lending Office" means the office of the Liquidity Provider in
         which it books this facility presently located at Chicago, Illinois, or
         such other office as the Liquidity Provider from time to time shall
         notify the Borrower as its "Lending Office" hereunder in which it books
         this facility; provided that the Liquidity Provider shall not change
         its Lending Office to a Lending Office outside the United States of
         America except in accordance with Section 3.01, 3.02 or 3.03 hereof.

                  "LIBOR Advance" means an Advance bearing interest at a rate
         based upon the LIBOR Rate.

                  "LIBOR Rate" means, with respect to any Interest Period, the
         rate per annum appearing on Page 3750 of the Dow Jones Markets Service
         (or any successor or substitute Page of such Service, or any successor
         to or substitute for such Service, providing rate quotations comparable
         to those currently provided on such Page applicable to deposits in
         dollars in the London interbank market) at approximately 11:00 A.M.
         (London time) two Business Days before the first day of such Interest
         Period for a period of time comparable to such Interest Period. In the
         event that such rate is not available at such time for any reason, then
         the LIBOR Rate with respect to any Interest Period shall be the rate
         per annum at which deposits in dollars are offered to major banks in
         the London interbank market at approximately 11:00 A.M. (London time)
         two Business Days before the first day of such Interest Period for a
         period of time comparable to such Interest Period.

                  "Liquidity Event of Default" means the occurrence of either
         (a) the Acceleration of all of the Equipment Notes (provided that, with
         respect to the period prior to the Delivery Period Expiry Date, such
         Equipment Notes have an aggregate outstanding principal balance in
         excess of $125,000,000) or (b) an America West Bankruptcy Event.
<PAGE>   9
                                                                               5

                  "Liquidity Indemnitee" means (i) the Liquidity Provider, (ii)
         the directors, officers, employees and agents of the Liquidity
         Provider, and (iii) the successors and permitted assigns of the persons
         described in clauses (i) and (ii), inclusive.

                  "Liquidity Provider" has the meaning assigned to such term in
         the recital of parties to this Agreement.

                  "Maximum Available Commitment" means, subject to the proviso
         contained in the third sentence of Section 2.02(a), at any time of
         determination, (a) the Maximum Commitment at such time less (b) the
         aggregate amount of each Interest Advance outstanding at such time;
         provided that following a Provider Advance or a Final Advance, the
         Maximum Available Commitment shall be zero.

                  "Maximum Commitment" means initially $4,703,902, as the same
         may be reduced from time to time in accordance with Section 2.04(a).

                  "Non-Extension Advance" means an advance made pursuant to
         Section 2.02(b).

                  "Notice of Borrowing" has the meaning specified in Section
         2.02(e).

                  "Notice of Replacement Subordination Agent" has the meaning
         specified in Section 3.08.

                  "Offering Memorandum" means the Offering Memorandum dated
         September 24, 1998 relating to the Certificates, as such Offering
         Memorandum may be amended or supplemented.

                  "Performing Note Deficiency" means any time that less than 65%
         of the then aggregate outstanding principal amount of all Equipment
         Notes are Performing Equipment Notes.

                  "Provider Advance" means a Downgrade Advance or a
         Non-Extension Advance.

                  "Regulatory Change" has the meaning assigned to such term in
         Section 3.01.

                  "Replenishment Amount" has the meaning assigned to such term
         in Section 2.06(b).

                  "Required Amount" means, for any day, the sum of the aggregate
         amount of interest, calculated at the rate per annum equal to the
         Stated Interest Rate for the Class B Certificates, that would be
         payable on the Class B Certificates on each of the three successive
         semiannual Regular Distribution Dates immediately following such day
         or, if such day is a Regular Distribution Date, on such day and the
         succeeding two semiannual Regular Distribution Dates, in each case
         calculated on the basis of the Pool Balance of the Class B Certificates
         on such day and without regard to expected future payments of principal
         on the Class B Certificates.
<PAGE>   10
                                                                               6

                  "Successor Trust" means America West Airlines Pass Through
         Trust 1998-1B-S.

                  "Termination Date" means the earliest to occur of the
         following: (i) the Expiry Date; (ii) the date on which the Borrower
         delivers to the Liquidity Provider a certificate, signed by a
         Responsible Officer of the Borrower, certifying that all of the Class B
         Certificates have been paid in full (or provision has been made for
         such payment in accordance with the Intercreditor Agreement and the
         Trust Agreements) or are otherwise no longer entitled to the benefits
         of this Agreement; (iii) the date on which the Borrower delivers to the
         Liquidity Provider a certificate, signed by a Responsible Officer of
         the Borrower, certifying that a Replacement Liquidity Facility has been
         substituted for this Agreement in full pursuant to Section 3.6(e) of
         the Intercreditor Agreement; (iv) the fifth Business Day following the
         receipt by the Borrower of a Termination Notice from the Liquidity
         Provider pursuant to Section 6.01 hereof; and (v) the date on which no
         Advance is or may (including by reason of reinstatement as herein
         provided) become available for a Borrowing hereunder.

                  "Termination Notice" means the Notice of Termination
         substantially in the form of Annex V to this Agreement.

                  "Transferee" has the meaning assigned to such term in Section
         7.08(b).

                  "Unapplied Downgrade Advance" means any Downgrade Advance
         other than an Applied Downgrade Advance.

                  "Unapplied Provider Advance" means any Provider Advance other
         than an Applied Provider Advance.

                  "Unpaid Advance" has the meaning assigned to such term in
         Section 2.05.

                  (b) Terms Defined in the Intercreditor Agreement. For all
         purposes of this Agreement, the following terms shall have the
         respective meanings assigned to such terms in the Intercreditor
         Agreement:

         "Acceleration", "America West", "America West Bankruptcy Event",
         "Certificates", "Class A Certificates", "Class B Cash Collateral
         Account", "Class B Certificates", "Class B Certificateholders", "Class
         B Trust", "Class B Trust Agreement", "Class B Trustee", "Class C
         Certificates", "Closing Date", "Controlling Party", "Corporate Trust
         Office", "Delivery Period Expiry Date", "Distribution Date",
         "Downgraded Facility", "Equipment Notes", "Fee Letter", "Final Legal
         Distribution Date", "Financing Agreement", "Indenture", "Initial
         Purchasers", "Interest Payment Date", "Investment Earnings", "Liquidity
         Facility", "Liquidity Obligations", "Loan Trustee", "Moody's",
         "Non-Extended Facility", "Note Purchase Agreement", "Operative
         Agreements", "Performing Equipment Note", "Person", "Pool Balance",
         "Purchase Agreement", "Rating Agency", "Ratings Confirmation", "Regular
         Distribution Date", "Replacement Liquidity Facility", "Responsible
         Officer", "Scheduled Payment", "Special Payment", "Standard & Poor's",
         "Stated Interest Rate", "Subordination Agent", "Taxes", "Threshold
         Rating", "Transfer", "Trust Agreements", "Trustee", and "Written
         Notice".
<PAGE>   11
                                                                               7

                                   ARTICLE II

                       AMOUNT AND TERMS OF THE COMMITMENT

                  Section 2.01. The Advances. The Liquidity Provider hereby
irrevocably agrees, on the terms and conditions hereinafter set forth, to make
Advances to the Borrower from time to time on any Business Day during the period
from the Effective Date until 12:00 Noon (New York City time) on the Expiry Date
(unless the obligations of the Liquidity Provider shall be earlier terminated in
accordance with the terms of Section 2.04(b)) in an aggregate amount at any time
outstanding not to exceed the Maximum Commitment.

                  Section 2.02. Making the Advances. (a) Interest Advances shall
be made in one or more Borrowings by delivery to the Liquidity Provider of one
or more written and completed Notices of Borrowing in substantially the form of
Annex I attached hereto, signed by a Responsible Officer of the Borrower, in an
amount not exceeding the Maximum Available Commitment at such time and shall be
used solely for the payment when due of interest on the Class B Certificates at
the Stated Interest Rate therefor in accordance with Section 3.6(a) of the
Intercreditor Agreement. Each Interest Advance made hereunder shall
automatically reduce the Maximum Available Commitment by the amount of such
Interest Advance (subject to reinstatement as provided in the next sentence).
Upon repayment to the Liquidity Provider in full of the amount of any Interest
Advance made pursuant to this Section 2.02(a), together with accrued interest
thereon (as provided herein), the Maximum Available Commitment shall be
reinstated by the amount of such repaid Interest Advance, but not to exceed the
Maximum Commitment; provided, however, that the Maximum Available Commitment
shall not be so reinstated at any time if (i) a Liquidity Event of Default shall
have occurred and be continuing and (ii) there is a Performing Note Deficiency.

                  (b) A Non-Extension Advance shall be made in a single
Borrowing if this Agreement is not extended in accordance with Section 3.6(d) of
the Intercreditor Agreement (unless a Replacement Liquidity Facility to replace
this Agreement shall have been delivered to the Borrower as contemplated by said
Section 3.6(d) within the time period specified in such Section) by delivery to
the Liquidity Provider of a written and completed Notice of Borrowing in
substantially the form of Annex II attached hereto, signed by a Responsible
Officer of the Borrower, in an amount equal to the Maximum Available Commitment
at such time, and shall be used to fund the Class B Cash Collateral Account in
accordance with said Section 3.6(d) and Section 3.6(f) of the Intercreditor
Agreement.

                  (c) A Downgrade Advance shall be made in a single Borrowing
upon a downgrading of the Liquidity Provider's short-term unsecured debt rating
issued by either Rating Agency below the applicable Threshold Rating (as
provided for in Section 3.6(c) of the Intercreditor Agreement) unless a
Replacement Liquidity Facility to replace this Agreement shall have been
previously delivered to the Borrower in accordance with said Section 3.6(c), by
delivery to the Liquidity Provider of a written and completed Notice of
Borrowing in substantially the form of Annex III attached hereto, signed by a
Responsible Officer of the Borrower, in an amount equal to the Maximum Available
Commitment at such time, and shall be used to fund the Class B Cash Collateral
Account in accordance with said Section 3.6(c) and Section 3.6(f) of the
Intercreditor Agreement.
<PAGE>   12
                                                                               8

                  (d) A Final Advance shall be made in a single Borrowing upon
the receipt by the Borrower of a Termination Notice from the Liquidity Provider
pursuant to Section 6.01 hereof by delivery to the Liquidity Provider of a
written and completed Notice of Borrowing in substantially the form of Annex IV
attached hereto, signed by a Responsible Officer of the Borrower, in an amount
equal to the Maximum Available Commitment at such time, and shall be used to
fund the Class B Cash Collateral Account (in accordance with Section 3.6(i) of
the Intercreditor Agreement) and Section 3.6(f) of the Intercreditor Agreement.

                  (e) Each Borrowing shall be made on notice in writing (a
"Notice of Borrowing") in substantially the form required by Section 2.02(a),
2.02(b), 2.02(c) or 2.02(d), as the case may be, given by the Borrower to the
Liquidity Provider. If a Notice of Borrowing is delivered by the Borrower in
respect of any Borrowing no later than 1:00 p.m. (New York City time) on a
Business Day, upon satisfaction of the conditions precedent set forth in Section
4.02 with respect to a requested Borrowing, the Liquidity Provider shall make
available to the Borrower, in accordance with its payment instructions, the
amount of such Borrowing in U.S. dollars and immediately available funds, before
3:00 p.m. (New York City time) on such Business Day or on such later Business
Day specified in such Notice of Borrowing. If a Notice of Borrowing is delivered
by the Borrower in respect of any Borrowing after 1:00 p.m. (New York City time)
on a Business Day, upon satisfaction of the conditions precedent set forth in
Section 4.02 with respect to a requested Borrowing, the Liquidity Provider shall
make available to the Borrower, in accordance with its payment instructions, the
amount of such Borrowing in U.S. dollars and immediately available funds, before
12:00 Noon (New York City time) on the first Business Day next following the day
of receipt of such Notice of Borrowing or on such later Business Day specified
by the Borrower in such Notice of Borrowing. Payments of proceeds of a Borrowing
shall be made by wire transfer of immediately available funds to the Borrower in
accordance with such wire transfer instructions as the Borrower shall furnish
from time to time to the Liquidity Provider for such purpose. Each Notice of
Borrowing shall be irrevocable and binding on the Borrower.

                  (f) Upon the making of any Advance requested pursuant to a
Notice of Borrowing, in accordance with the Borrower's payment instructions, the
Liquidity Provider shall be fully discharged of its obligation hereunder with
respect to such Notice of Borrowing, and the Liquidity Provider shall not
thereafter be obligated to make any further Advances hereunder in respect of
such Notice of Borrowing to the Borrower or to any other Person. Following the
making of any Advance pursuant to Section 2.02(b), (c) or (d) hereof to fund the
Class B Cash Collateral Account, the Liquidity Provider shall have no interest
in or rights to the Class B Cash Collateral Account, such Advance or any other
amounts from time to time on deposit in the Class B Cash Collateral Account;
provided that the foregoing shall not affect or impair the obligations of the
Subordination Agent to make the distributions contemplated by Section 3.6(e) or
(f) of the Intercreditor Agreement. By paying to the Borrower proceeds of
Advances requested by the Borrower in accordance with the provisions of this
Agreement, the Liquidity Provider makes no representation as to, and assumes no
responsibility for, the correctness or sufficiency for any purpose of the amount
of the Advances so made and requested.

                  Section 2.03. Fees. The Borrower agrees to pay to the
Liquidity Provider the fees set forth in the Fee Letter.

                  Section 2.04. Adjustments or Termination of the Maximum
Commitment.
<PAGE>   13
                                                                               9

                  (a) Automatic Adjustments. Promptly following each date on
which the Required Amount is (1) reduced as a result of a reduction in the Pool
Balance of the Class B Certificates or otherwise, (2) increased as a result of
an increase in the Stated Interest Rate or (3) subsequent to such an increase
described in clause (2), reduced pursuant to the definition of "Stated Interest
Rate", the Maximum Commitment shall automatically be reduced or increased, as
the case may be, to an amount equal to the Required Amount (as calculated by the
Borrower). The Borrower shall give notice of any such automatic reduction or
increase, as the case may be, of the Maximum Commitment to the Liquidity
Provider within two Business Days thereof. The failure by the Borrower to
furnish any such notice shall not affect such automatic reduction or increase of
the Maximum Commitment.

                  (b) Termination. Upon the making of any Provider Advance or
Final Advance hereunder or the occurrence of the Termination Date, the
obligation of the Liquidity Provider to make further Advances hereunder shall
automatically and irrevocably terminate, and the Borrower shall not be entitled
to request any further Borrowing hereunder.

                  Section 2.05. Repayments of Interest Advances or the Final
Advance. Subject to Sections 2.06, 2.07 and 2.09 hereof, the Borrower hereby
agrees, without notice of an Advance or demand for repayment from the Liquidity
Provider (which notice and demand are hereby waived by the Borrower), to pay, or
to cause to be paid, to the Liquidity Provider on each date on which the
Liquidity Provider shall make an Interest Advance or the Final Advance, an
amount equal to (a) the amount of such Advance (any such Advance, until repaid,
is referred to herein as an "Unpaid Advance"), plus (b) interest on the amount
of each such Unpaid Advance as provided in Section 3.07 hereof; provided that if
(i) the Liquidity Provider shall make a Provider Advance at any time after
making one or more Interest Advances which shall not have been repaid in
accordance with this Section 2.05 or (ii) this Liquidity Facility shall become a
Downgraded Facility or Non-Extended Facility at any time when unreimbursed
Interest Advances have reduced the Maximum Available Commitment to zero, then
such Interest Advances shall cease to constitute Unpaid Advances and shall be
deemed to have been changed into an Applied Downgrade Advance or an Applied
Non-Extension Advance, as the case may be, for all purposes of this Agreement
(including, without limitation, for the purpose of determining when such
Interest Advance is required to be repaid to the Liquidity Provider in
accordance with Section 2.06 and for the purposes of Section 2.06(b)). The
Borrower and the Liquidity Provider agree that the repayment in full of each
Interest Advance and Final Advance on the date such Advance is made is intended
to be a contemporaneous exchange for new value given to the Borrower by the
Liquidity Provider.

                  Section 2.06. Repayments of Provider Advances. (a) Amounts
advanced hereunder in respect of a Provider Advance shall be deposited in the
Class B Cash Collateral Account, invested and withdrawn from the Class B Cash
Collateral Account as set forth in Sections 3.6(c), (d) and (f) of the
Intercreditor Agreement. The Borrower agrees to pay to the Liquidity Provider,
on each Regular Distribution Date, commencing on the first Regular Distribution
Date after the making of a Provider Advance, interest on the principal amount of
any such Provider Advance as provided in Section 3.07; provided, however, that
amounts in respect of a Provider Advance withdrawn from the Class B Cash
Collateral Account for the purpose of paying interest on the Class B
Certificates in accordance with Section 3.6(f) of the Intercreditor Agreement
(the amount of any such withdrawal being (y) in the case of a 
<PAGE>   14
                                                                              10

Downgrade Advance, an "Applied Downgrade Advance" and (z) in the case of a
Non-Extension Advance, an "Applied Non-Extension Advance" and, together with an
Applied Downgrade Advance, an "Applied Provider Advance") shall thereafter
(subject to Section 2.06(b)) be treated as an Interest Advance under this
Agreement for purposes of determining the Applicable Liquidity Rate for interest
payable thereon; provided further, however, that if, following the making of a
Provider Advance, the Liquidity Provider delivers a Termination Notice to the
Borrower pursuant to Section 6.01 hereof, such Provider Advance shall thereafter
be treated as a Final Advance under this Agreement for purposes of determining
the Applicable Liquidity Rate for interest payable thereon. Subject to Sections
2.07 and 2.09 hereof, immediately upon the withdrawal of any amounts from the
Class B Cash Collateral Account on account of a reduction in the Required
Amount, the Borrower shall repay to the Liquidity Provider a portion of the
Provider Advances in a principal amount equal to such reduction, plus interest
on the principal amount prepaid as provided in Section 3.07 hereof.

                  (b) At any time when an Applied Provider Advance (or any
portion thereof) is outstanding, upon the deposit in the Class B Cash Collateral
Account of any amount pursuant to clause "third" of Section 2.4(b) of the
Intercreditor Agreement, clause "third" of Section 3.2 of the Intercreditor
Agreement or clause "fourth" of Section 3.3 of the Intercreditor Agreement (any
such amount being a "Replenishment Amount") for the purpose of replenishing or
increasing the balance thereof up to the Required Amount at such time, (i) the
aggregate outstanding principal amount of all Applied Provider Advances (and of
Provider Advances treated as an Interest Advance for purposes of determining the
Applicable Liquidity Rate for interest payable thereon) shall be automatically
reduced by the amount of such Replenishment Amount and (ii) the aggregate
outstanding principal amount of all Unapplied Provider Advances shall be
automatically increased by the amount of such Replenishment Amount.

                  (c) Upon the provision of a Replacement Liquidity Facility in
replacement of this Agreement in accordance with Section 3.6(e) of the
Intercreditor Agreement, amounts remaining on deposit in the Class B Cash
Collateral Account after giving effect to any Applied Provider Advance on the
date of such replacement shall be reimbursed to the Liquidity Provider, but only
to the extent such amounts are necessary to repay in full to the Liquidity
Provider all amounts owing to it hereunder.

                  Section 2.07. Payments to the Liquidity Provider Under the
Intercreditor Agreement. In order to provide for payment or repayment to the
Liquidity Provider of any amounts hereunder, the Intercreditor Agreement
provides that amounts available and referred to in Articles II and III of the
Intercreditor Agreement, to the extent payable to the Liquidity Provider
pursuant to the terms of the Intercreditor Agreement (including, without
limitation, Section 3.6(f) of the Intercreditor Agreement), shall be paid to the
Liquidity Provider in accordance with the terms thereof. Amounts so paid to the
Liquidity Provider shall be applied by the Liquidity Provider to Liquidity
Obligations then due and payable in accordance with the Intercreditor Agreement
or, if not provided for in the Intercreditor Agreement, then in such manner as
the Liquidity Provider shall deem appropriate.

                  Section 2.08. Book Entries. The Liquidity Provider shall
maintain in accordance with its usual practice an account or accounts evidencing
the indebtedness of the Borrower resulting from Advances made from time to time
and the amounts of principal and interest payable hereunder and paid from time
to time in respect thereof; provided, however, that the
<PAGE>   15
                                                                              11

failure by the Liquidity Provider to maintain such account or accounts shall not
affect the obligations of the Borrower in respect of Advances.

                  Section 2.09. Payments from Available Funds Only. All payments
to be made by the Borrower under this Agreement shall be made only from the
amounts that constitute Scheduled Payments, Special Payments or payments under
Section 7.1 or 9.1, as the case may be, of the Participation Agreements and
Section 6 of the Note Purchase Agreement and only to the extent that the
Borrower shall have sufficient income or proceeds therefrom to enable the
Borrower to make payments in accordance with the terms hereof after giving
effect to the priority of payments provisions set forth in the Intercreditor
Agreement. The Liquidity Provider agrees that it will look solely to such
amounts to the extent available for distribution to it as provided in the
Intercreditor Agreement and this Agreement and that the Borrower, in its
individual capacity, is not personally liable to it for any amounts payable or
liability under this Agreement except as expressly provided in this Agreement,
the Intercreditor Agreement or any Participation Agreement. Amounts on deposit
in the Class B Cash Collateral Account shall be available to the Borrower to
make payments under this Agreement only to the extent and for the purposes
expressly contemplated in Section 3.6(f) of the Intercreditor Agreement.

                  Section 2.10. Extension of the Expiry Date; Non-Extension
Advance. No earlier than the 60th day and no later than the 40th day prior to
the then effective Expiry Date (unless such Expiry Date is on or after the date
that is 15 days after the Final Legal Distribution Date for the Class B
Certificates), the Borrower shall request that the Liquidity Provider extend the
Expiry Date for a period of 364 days after the then effective Expiry Date
(unless the obligations of the Liquidity Provider are earlier terminated in
accordance with the terms hereof). The Liquidity Provider shall advise the
Borrower, no earlier than 40 days and no later than 25 days prior to the then
effective Expiry Date, whether, in its sole discretion, it agrees to so extend
the Expiry Date. If the Liquidity Provider advises the Borrower on or before the
25th day prior to the Expiry Date then in effect that such Expiry Date shall not
be so extended, or fails to irrevocably and unconditionally advise the Borrower
on or before the 25th day prior to the Expiry Date then in effect that such
Expiry Date shall be so extended (and, in each case, if the Liquidity Provider
shall not have been replaced in accordance with Section 3.6(e) of the
Intercreditor Agreement), the Borrower shall be entitled on and after such 25th
day (but prior to the then effective Expiry Date) to request a Non-Extension
Advance in accordance with Section 2.02(b) hereof and Section 3.6(d) of the
Intercreditor Agreement.
<PAGE>   16
                                                                              12

                                   ARTICLE III

                           OBLIGATIONS OF THE BORROWER

                  Section 3.01. Increased Costs. The Borrower shall pay to the
Liquidity Provider from time to time such amounts as may be necessary to
compensate the Liquidity Provider for any increased costs incurred by the
Liquidity Provider which are reasonably attributable to its making or
maintaining any LIBOR Advances hereunder or its obligation to make any such
Advances hereunder, or any reduction in any amount receivable by the Liquidity
Provider under this Agreement or the Intercreditor Agreement in respect of any
such Advances or such obligation (such increases in costs and reductions in
amounts receivable being herein called "Additional Costs"), resulting from any
change after the date of this Agreement in U.S. federal, state, municipal, or
foreign laws or regulations (including Regulation D of the Board of Governors of
the Federal Reserve System applicable to banks generally), or the adoption or
making after the date of this Agreement of any interpretations, directives, or
requirements applying to a class of banks including the Liquidity Provider under
any U.S. federal, state, municipal, or any foreign laws or regulations (whether
or not having the force of law but of the type with which the Liquidity Provider
is accustomed to comply) by any court, central bank or monetary authority
charged with the interpretation or administration thereof in each case not
publicly announced on the date hereof (a "Regulatory Change"), which: (1)
changes the basis of taxation of any amounts payable to the Liquidity Provider
under this Agreement in respect of any such Advances (other than Excluded
Taxes); or (2) imposes or modifies any reserve, special deposit, compulsory loan
or similar requirements relating to any extensions of credit hereunder in
respect of LIBOR Advances (including any such Advances or any deposits referred
to in the definition of LIBOR Rate or related definitions), other than (i) costs
which arise as a result of the Liquidity Provider willfully contravening or
exceeding any operating limits or other restrictions imposed on it by any
authority; or (ii) if the increased costs would not have arisen but for any
assignment to another Liquidity Provider or an alteration in the lending office
of the Liquidity Provider. The Liquidity Provider agrees to use reasonable
efforts (consistent with applicable legal and regulatory restrictions) to change
the jurisdiction of its Lending Office if making such change would avoid the
need for, or reduce the amount of, any amount payable under this Section that
may thereafter accrue and would not, in the reasonable judgment of the Liquidity
Provider, be otherwise materially disadvantageous to the Liquidity Provider.

                  The Liquidity Provider will notify the Borrower of any event
occurring after the date of this Agreement that will entitle the Liquidity
Provider to compensation pursuant to this Section 3.01 as promptly as
practicable after it obtains knowledge thereof and determines to request such
compensation, which notice shall describe in reasonable detail the calculation
of the amounts owed under this Section; provided, that if the Liquidity Provider
fails to give such notice within 30 days after it obtains such knowledge, the
Liquidity Provider shall, with respect to any costs resulting from such event,
only be entitled to payment under this Section 3.01 for costs incurred from and
after the date 30 days prior to the date the Liquidity Provider does give such
notice. Determinations by the Liquidity Provider for purposes of this Section
3.01 of the effect of any Regulatory Change on its costs of making or
maintaining Advances or on amounts receivable by it in respect of Advances, and
of the additional amounts required to compensate the Liquidity Provider in
respect of any Additional Costs, shall be prima facie evidence of the amount
owed under this Section.
<PAGE>   17
                                                                              13

                  The Liquidity Provider shall not be entitled to compensation
under this Section 3.01 if (1) it shall not be also seeking compensation (if it
should be so entitled) under other comparable contractual provisions in its
other agreements, (2) if its claim under this Section 3.01 arises through
circumstances peculiar to the Liquidity Provider and which do not affect a
similarly organized commercial banking institution in the same jurisdiction
generally, or (3) the Liquidity Provider is not the initial liquidity provider
and America West did not consent to the transfer of this facility to the
Liquidity Provider, for the amount, if any, payable under this Section 3.01
resulting from events occurring prior to the date the Liquidity Provider
acquired its interests hereunder as shall exceed the amount payable under this
Section 3.01 that would have been due to the Liquidity Provider's transferor had
it continued to be the liquidity provider hereunder.

                  Section 3.02. Capital Adequacy. If (1) the adoption, after the
date hereof, of any applicable governmental law, rule or regulation regarding
capital adequacy and not publicly announced on the date hereof, (2) any change,
after the date hereof, in the interpretation or administration of any such law,
rule or regulation by any central bank or other governmental authority charged
with the interpretation or administration thereof and not publicly announced on
the date hereof or (3) compliance by the Liquidity Provider or any corporation
controlling the Liquidity Provider with any applicable guideline or request of
general applicability, issued after the date hereof and not publicly announced
on the date hereof, by any central bank or other governmental authority (whether
or not having the force of law but of the type with which the Liquidity Provider
is accustomed to comply) that constitutes a change of the nature described in
clause (2), has the effect of requiring an increase in the amount of capital
required to be maintained by the Liquidity Provider or any corporation
controlling the Liquidity Provider, and such increase is based upon the
Liquidity Provider's obligations hereunder and other similar obligations, the
Borrower shall pay to the Liquidity Provider from time to time such additional
amount or amounts as are necessary to compensate the Liquidity Provider for such
portion of such increase as shall be reasonably allocable to the Liquidity
Provider's obligations to the Borrower hereunder. The Liquidity Provider agrees
to use reasonable efforts (consistent with applicable legal and regulatory
restrictions) to change the jurisdiction of its Lending Office if making such
change would avoid the need for, or reduce the amount of, any amount payable
under this Section that may thereafter accrue and would not, in the reasonable
judgment of the Liquidity Provider, be otherwise materially disadvantageous to
the Liquidity Provider.

                  The Liquidity Provider will notify the Borrower of any event
occurring after the date of this Agreement that will entitle the Liquidity
Provider to compensation pursuant to this Section 3.02 as promptly as
practicable after it obtains knowledge thereof and determines to request such
compensation, which notice shall describe in reasonable detail the calculation
of the amounts owed under this Section; provided that if the Liquidity Provider
fails to give such notice within 30 days after it obtains such knowledge, the
Liquidity Provider shall, with respect of any costs resulting from such event,
only be entitled to payment under this Section 3.02 for costs incurred from and
after the date 30 days prior to the date the Liquidity Provider does give such
notice. Determinations by the Liquidity Provider for purposes of this Section
3.02 of the effect of any increase in the amount of capital required to be
maintained by the Liquidity Provider and of the amount allocable to the
Liquidity Provider's obligations to the Borrower hereunder shall be prima facie
evidence of the amounts owed under this Section.
<PAGE>   18
                                                                              14

                  The Liquidity Provider shall not be entitled to compensation
under this Section 3.02 if (1) it shall not be also seeking compensation (if it
should be so entitled) under other comparable contractual provisions in its
other agreements, (2) if its claim under this Section 3.02 arises through
circumstances peculiar to the Liquidity Provider and which do not affect a
similarly organized commercial banking institution in the same jurisdiction
generally, or (3) the Liquidity Provider is not the initial liquidity provider
and America West did not consent to the transfer of this facility to the
Liquidity Provider, for the amount, if any, payable under this Section 3.02
resulting from events occurring prior to the date the Liquidity Provider
acquired its interests hereunder as shall exceed the amount payable under this
Section 3.02 that would have been due to the Liquidity Provider's transferor had
it continued to be the liquidity provider hereunder.

                  Section 3.03. Payments Free of Deductions. (a) All payments
made by the Borrower under this Agreement shall be made free and clear of, and
without reduction for or on account of, any present or future stamp or other
taxes, levies, imposts, duties, deductions or withholdings, of a similar nature
other than Excluded Taxes (collectively, "Non-Excluded Taxes" and, individually,
a "Non-Excluded Tax"). If any Non-Excluded Taxes are required to be withheld
from any amounts payable to the Liquidity Provider under this Agreement, the
Liquidity Provider shall notify the Borrower and America West thereof and from
and after such notice, the amounts so payable to the Liquidity Provider shall be
increased to the extent necessary to yield to the Liquidity Provider (after
payment of all Non-Excluded Taxes) the amount it would have received had no such
deduction or withholding occurred. The Liquidity Provider agrees to use
reasonable efforts (consistent with its legal and regulatory restrictions) to
change the jurisdiction of its Lending Office if making such change would avoid
the need for, or reduce the amount of, any such additional amounts that may
thereafter accrue and shall otherwise take such reasonable steps as are open to
it to mitigate the effects of such circumstances provided that the Liquidity
Provider shall be under no obligation to take any such action if to do so would
have a material adverse effect on its business, operations or financial
condition or result in its rights, interests or position under this Agreement
being prejudiced or involved in any unlawful activity. From time to time upon
the reasonable request of the Borrower, the Liquidity Provider agrees to provide
to the Borrower two original Internal Revenue Service Form 1001 or 4224, as
appropriate, or any successor or other form prescribed by the Internal Revenue
Service, certifying that the Liquidity Provider is exempt from or entitled to a
reduced rate of United States withholding tax on payments pursuant to this
Agreement.

                  Section 3.04. Payments. The Borrower shall make or cause to be
made each payment to the Liquidity Provider under this Agreement so as to cause
the same to be received by the Liquidity Provider not later than 1:00 P.M. (New
York City time) on the day when due. The Borrower shall make all such payments
in lawful money of the United States of America, to the Liquidity Provider in
immediately available funds, by wire transfer to ABN AMRO Bank N.V., New York,
New York, ABA # 026009580 for account of ABN AMRO Bank N.V., Chicago Branch CPU,
Account No. 650-001-1789-41, Account Reference: America West Airlines Liquidity
Facility 1998-1B.

                  Section 3.05. Computations. All computations of interest based
on the Base Rate shall be made on the basis of a year of 365 or 366 days, as the
case may be, and all computations of interest based on the LIBOR Rate shall be
made on the basis of a year of 360 days, in each
<PAGE>   19
                                                                              15

case for the actual number of days (including the first day but excluding the
last day) occurring in the period for which such interest is payable.

                  Section 3.06. Payment on Non-Business Days. Whenever any
payment to be made hereunder shall be stated to be due on a day other than a
Business Day, such payment shall be made on the next succeeding Business Day and
no additional interest shall be due as a result (and if so made, shall be deemed
to have been made when due). If any payment in respect of interest on an Advance
is so deferred to the next succeeding Business Day, such deferral shall not
delay the commencement of the next Interest Period for such Advance (if such
Advance is a LIBOR Advance) or reduce the number of days for which interest will
be payable on such Advance on the next interest payment date for such Advance.

                  Section 3.07. Interest. (a) Subject to Section 2.09, the
Borrower shall pay, or shall cause to be paid, without duplication, interest on
(i) the unpaid principal amount of each Advance from and including the date of
such Advance (or, in the case of an Applied Provider Advance, from and including
the date on which the amount thereof was withdrawn from the Class B Cash
Collateral Account to pay interest on the Class B Certificates) to but excluding
the date such principal amount shall be paid in full (or, in the case of an
Applied Provider Advance, the date on which the Class B Cash Collateral Account
is fully replenished in respect of such Advance) and (ii) any other amount due
hereunder (whether fees, commissions, expenses or other amounts or, to the
extent permitted by law, installments of interest on Advances or any such other
amount) which is not paid when due (whether at stated maturity, by acceleration
or otherwise) from and including the due date thereof to but excluding the date
such amount is paid in full, in each such case, at a fluctuating interest rate
per annum for each day equal to the Applicable Liquidity Rate for such Advance
or such other amount as in effect for such day, but in no event at a rate per
annum greater than the maximum rate permitted by applicable law; provided,
however, that, if at any time the otherwise applicable interest rate as set
forth in this Section 3.07 shall exceed the maximum rate permitted by applicable
law, then any subsequent reduction in such interest rate will not reduce the
rate of interest payable pursuant to this Section 3.07 below the maximum rate
permitted by applicable law until the total amount of interest accrued equals
the amount of interest that would have accrued if such otherwise applicable
interest rate as set forth in this Section 3.07 had at all times been in effect.

                  (b) Each Advance will be either a Base Rate Advance or a LIBOR
Advance as provided in this Section. Each such Advance will be a Base Rate
Advance for the period from the date of its borrowing to (but excluding) the
third Business Day following the Liquidity Provider's receipt of the Notice of
Borrowing for such Advance. Thereafter, such Advance shall be a LIBOR Advance.

                  (c) Each LIBOR Advance shall bear interest during each
Interest Period at a rate per annum equal to the LIBOR Rate for such Interest
Period plus the Applicable Margin for such LIBOR Advance, payable in arrears on
the last day of such Interest Period and, in the event of the payment of
principal of such LIBOR Advance on a day other than such last day, on the date
of such payment (to the extent of interest accrued on the amount of principal
repaid).

                  (d) Each Base Rate Advance shall bear interest at a rate per
annum equal to the Base Rate plus the Applicable Margin for such Base Rate
Advance, payable in arrears on each Regular Distribution Date and, in the event
of the payment of principal of such Base Rate
<PAGE>   20
                                                                              16

Advance on a day other than a Regular Distribution Date, on the date of such
payment (to the extent of interest accrued on the amount of principal repaid).

                  (e) Each amount not paid when due hereunder (whether fees,
commissions, expenses or other amounts or, to the extent permitted by applicable
law, installments of interest on Advances but excluding Advances) shall bear
interest at a rate per annum equal to the Base Rate plus 2% until paid.

                  (f) Each change in the Base Rate shall become effective
immediately. The rates of interest specified in this Section 3.07 with respect
to any Advance or other amount shall be referred to as the "Applicable Liquidity
Rate".

                  Section 3.08. Replacement of Subordination Agent. From time to
time and subject to the successor Subordination Agent's meeting the eligibility
requirements set forth in Section 6.9 of the Intercreditor Agreement applicable
to the Subordination Agent, upon the effective date and time specified in a
written and completed Notice of Replacement Subordination Agent in substantially
the form of Annex VI attached hereto (a "Notice of Replacement Subordination
Agent") delivered to the Liquidity Provider by the then Subordination Agent, the
successor Subordination Agent designated therein shall be substituted for as the
Subordination Agent for all purposes hereunder.

                  Section 3.09. Funding Loss Indemnification. The Borrower shall
pay to the Liquidity Provider, upon the request of the Liquidity Provider, such
amount or amounts as shall be sufficient (in the reasonable opinion of the
Liquidity Provider) to compensate it for any loss incurred by it by reason of
the liquidation or redeployment of deposits or other funds acquired by the
Liquidity Provider to fund or maintain any LIBOR Advance (but excluding loss of
anticipated profits) incurred as a result of:

                  (1) Any repayment of a LIBOR Advance on a date other than the
         last day of the Interest Period for such Advance; or

                  (2) Any failure by the Borrower to borrow a LIBOR Advance on
         the date for borrowing specified in the relevant notice under Section
         2.02.

                  Section 3.10. Illegality. Notwithstanding any other provision
in this Agreement, if any change in any applicable law, rule or regulation not
publicly announced on the date hereof shall make it unlawful or impossible for
the Liquidity Provider (or its Lending Office) to maintain or fund its LIBOR
Advances without breaking such law, then upon notice to the Borrower by the
Liquidity Provider, the outstanding principal amount of the LIBOR Advances shall
be converted to Base Rate Advances to the extent necessary to cure such
illegality (a) immediately upon demand of the Liquidity Provider, if such change
or compliance with such request, in the judgment of the Liquidity Provider,
requires immediate repayment; or (b) at the expiration of the last Interest
Period to expire before the effective date of any such change or request. The
Liquidity Provider agrees to use reasonable efforts (consistent with applicable
legal and regulatory restrictions) to change the jurisdiction of its Lending
Office if making such change would avoid or cure the aforesaid illegality.
<PAGE>   21
                                                                              17

                                   ARTICLE IV

                              CONDITIONS PRECEDENT

                  Section 4.01. Conditions Precedent to Effectiveness of Section
2.01. Section 2.01 of this Agreement shall become effective on and as of the
first date (the "Effective Date") on which the following conditions precedent
have been satisfied or waived:

                  (a) The Liquidity Provider shall have received on or before
         the Closing Date each of the following, and in the case of each
         document delivered pursuant to paragraphs (i), (ii) and (iii), each in
         form and substance satisfactory to the Liquidity Provider:

                           (i) This Agreement duly executed on behalf of the
                  Borrower;

                           (ii) The Intercreditor Agreement duly executed on
                  behalf of each of the parties thereto;

                           (iii) Fully executed copies of each of the Operative
                  Agreements executed and delivered on or before the Closing
                  Date (other than this Agreement and the Intercreditor
                  Agreement);

                           (iv) A copy of the Offering Memorandum and specimen
                  copies of the Class B Certificates;

                           (v) An executed copy of each document, instrument,
                  certificate and opinion delivered on or before the Closing
                  Date pursuant to the Class B Trust Agreement, the
                  Intercreditor Agreement and the other Operative Agreements (in
                  the case of each such opinion, other than the opinion of
                  counsel for the Initial Purchasers, either addressed to the
                  Liquidity Provider or accompanied by a letter from the counsel
                  rendering such opinion to the effect that the Liquidity
                  Provider is entitled to rely on such opinion as of its date as
                  if it were addressed to the Liquidity Provider);

                           (vi) Evidence that there shall have been made and
                  shall be in full force and effect, all filings, recordings
                  and/or registrations, and there shall have been given or taken
                  any notice or other similar action as are necessary or in
                  order to establish, perfect, protect and preserve the right,
                  title and interest of the Liquidity Provider created by the
                  Operative Agreements executed and delivered on or prior to the
                  Closing Date;

                           (vii) An agreement from America West, pursuant to
                  which America West agrees to provide copies of quarterly
                  financial statements and audited annual financial statements
                  to the Liquidity Provider (which obligations may be satisfied
                  by the furnishing of America West's Form 10Q and 10K), in each
                  case, only to the extent that America West is obligated to
                  provide such information pursuant to Section 8.2.1 of the
                  Leases (related to Leased Aircraft) or the corresponding
                  section of the Indentures (related to Owned Aircraft) to the
                  parties thereto; and
<PAGE>   22
                                                                              18

                           (viii) Such other documents, instruments, opinions
                  and approvals pertaining to the transactions contemplated
                  hereby or by the other Operative Agreements as the Liquidity
                  Provider shall have reasonably requested.

                  (b) The following statement shall be true on and as of the
         Effective Date: no event has occurred and is continuing, or would
         result from the entering into of this Agreement or the making of any
         Advance, which constitutes a Liquidity Event of Default.

                  (c) The Liquidity Provider shall have received payment in full
         of all fees and other sums required to be paid to or for account of the
         Liquidity Provider on or prior to the Effective Date.

                  (d) All conditions precedent to the issuance of the
         Certificates under the Trust Agreements shall have been satisfied or
         waived, all conditions precedent to the effectiveness of the other
         Liquidity Facilities shall have been satisfied or waived, and all
         conditions precedent to the purchase of the Certificates by the Initial
         Purchasers under the Purchase Agreement shall have been satisfied
         (unless any of such conditions precedent shall have been waived by the
         Initial Purchasers).

                  (e) The Borrower shall have received a certificate, dated the
         date hereof, signed by a duly authorized representative of the
         Liquidity Provider, certifying that all conditions precedent to the
         effectiveness of Section 2.01 have been satisfied or waived.

                  Section 4.02. Conditions Precedent to Borrowing. The
obligation of the Liquidity Provider to make an Advance on the occasion of each
Borrowing shall be subject to the conditions precedent that the Effective Date
shall have occurred and, prior to the date of such Borrowing, the Borrower shall
have delivered a Notice of Borrowing which conforms to the terms and conditions
of this Agreement and has been completed as may be required by the relevant form
of the Notice of Borrowing for the type of Advances requested.



                                    ARTICLE V

                                    COVENANTS

                  Section 5.01. Affirmative Covenants of the Borrower. So long
as any Advance shall remain unpaid or the Liquidity Provider shall have any
Maximum Commitment hereunder or the Borrower shall have any obligation to pay
any amount to the Liquidity Provider hereunder, the Borrower will, unless the
Liquidity Provider shall otherwise consent in writing:

                  (a) Performance of This and Other Agreements. Punctually pay
         or cause to be paid all amounts payable by it under this Agreement and
         the other Operative Agreements and observe and perform in all material
         respects the conditions, covenants and requirements applicable to it
         contained in this Agreement and the other Operative Agreements.
<PAGE>   23
                                                                              19

                  (b) Reporting Requirements. Furnish to the Liquidity Provider
         with reasonable promptness, such other information and data with
         respect to the transactions contemplated by the Operative Agreements as
         from time to time may be reasonably requested by the Liquidity
         Provider; and permit the Liquidity Provider, upon reasonable notice, to
         inspect the Borrower's books and records with respect to such
         transactions and to meet with officers and employees of the Borrower to
         discuss such transactions.

                  (c) Certain Operative Agreements. Furnish to the Liquidity
         Provider with reasonable promptness, such Operative Agreements entered
         into after the date hereof as from time to time may be reasonably
         requested by the Liquidity Provider.

                  Section 5.02. Negative Covenants of the Borrower. So long as
any Advance shall remain unpaid or the Liquidity Provider shall have any Maximum
Commitment hereunder or the Borrower shall have any obligation to pay any amount
to the Liquidity Provider hereunder, the Borrower will not appoint or permit or
suffer to be appointed any successor Borrower without the prior written consent
of the Liquidity Provider, which consent shall not be unreasonably withheld or
delayed.


                                   ARTICLE VI

                           LIQUIDITY EVENTS OF DEFAULT

                  Section 6.01. Liquidity Events of Default. If (a) any
Liquidity Event of Default has occurred and is continuing and (b) there is a
Performing Note Deficiency, the Liquidity Provider may, in its discretion,
deliver to the Borrower a Termination Notice, the effect of which shall be to
cause (i) the obligation of the Liquidity Provider to make Advances hereunder to
expire on the fifth Business Day after the date on which such Termination Notice
is received by the Borrower, (ii) the Borrower to promptly request, and the
Liquidity Provider to promptly make, a Final Advance in accordance with Section
2.02(d) hereof and Section 3.6(i) of the Intercreditor Agreement, (iii) all
other outstanding Advances to be automatically converted into Final Advances for
purposes of determining the Applicable Liquidity Rate for interest payable
thereon, and (iv) subject to Sections 2.07 and 2.09 hereof, all Advances
(including, without limitation, any Provider Advance and Applied Provider
Advance), any accrued interest thereon and any other amounts outstanding
hereunder to become immediately due and payable to the Liquidity Provider.


                                   ARTICLE VII

                                  MISCELLANEOUS

                  Section 7.01. Amendments, Etc. No amendment or waiver of any
provision of this Agreement, nor consent to any departure by the Borrower
therefrom, shall in any event be effective unless the same shall be in writing
and signed by the Liquidity Provider, and, in the case of an amendment or of a
waiver by the Borrower, the Borrower, and then such waiver or consent shall be
effective only in the specific instance and for the specific purpose for which
given.
<PAGE>   24
                                                                              20

                  Section 7.02. Notices, Etc. Except as otherwise expressly
provided herein, all notices and other communications provided for hereunder
shall be in writing (including telecopier and mailed or delivered or sent by
telecopier):

                  Borrower:

                  Wilmington Trust Company
                  Rodney Square North
                  1100 North Market Square
                  Wilmington, DE  19890-0001

                  Attention: Corporate Trust Administration
                  Telephone: 302-651-1000
                  Telecopy: 302-651-8882

                  Liquidity Provider:

                  ABN AMRO BANK N.V.
                  135 South LaSalle Street - Suite 660
                  Chicago, Illinois 60603

                  Attention:  Vice President - Aerospace
                  Telephone:  (312) 904-2900
                  Telecopy:  (312) 606-8428

                  with a copy to:

                  ABN AMRO BANK N.V.
                  135 South LaSalle Street - Suite 625
                  Chicago, Illinois 60603

                  Attention:  Loan Administration
                  Telephone:  (312) 904-2961
                  Telecopy:  (312) 904-1288

or, as to each of the foregoing, at such other address as shall be designated by
such Person in a written notice to the others. All such notices and
communications shall be effective when received unless received outside of
business hours, in which case on the next open of business on a Business Day. A
copy of all notices delivered hereunder to either party shall in addition be
delivered to each of the parties to the Participation Agreements at their
respective addresses set forth therein.

                  Section 7.03. No Waiver; Remedies. No failure on the part of
the Liquidity Provider to exercise, and no delay in exercising, any right under
this Agreement shall operate as a waiver thereof; nor shall any single or
partial exercise of any right under this Agreement preclude any other or further
exercise thereof or the exercise of any other right. The remedies herein
provided are cumulative and not exclusive of any remedies provided by law.
<PAGE>   25
                                                                              21

                  Section 7.04. Further Assurances. The Borrower agrees to do
such further acts and things and to execute and deliver to the Liquidity
Provider such additional assignments, agreements, powers and instruments as the
Liquidity Provider may reasonably require or deem advisable to carry into effect
the purposes of this Agreement and the other Operative Agreements or to better
assure and confirm unto the Liquidity Provider its rights, powers and remedies
hereunder and under the other Operative Agreements.

                  Section 7.05. Indemnification; Survival of Certain Provisions.
The Liquidity Provider shall be indemnified hereunder to the extent and in the
manner described in Section 7.1 or 9.1, as the case may be, of the Participation
Agreements. The indemnities contained in Section 7.1 or 9.1, as the case may be,
of the Participation Agreements, and the provisions of Sections 3.01, 3.02,
3.03, 3.09, 7.05 and 7.07 hereof, shall survive the termination of this
Agreement.

                  Section 7.06. Liability of the Liquidity Provider. (a) Neither
the Liquidity Provider nor any of its officers, employees, directors or
affiliates shall be liable or responsible for: (i) the use which may be made of
the Advances or any acts or omissions of the Borrower or any beneficiary or
transferee in connection therewith; or (ii) the validity, sufficiency or
genuineness of documents, or of any endorsement thereon, even if such documents
should prove to be in any or all respects invalid, insufficient, fraudulent or
forged except as executed by the Liquidity Provider; provided, however, that the
Borrower shall have a claim against the Liquidity Provider, and the Liquidity
Provider shall be liable to the Borrower, to the extent of any damages suffered
by the Borrower which were the result of (A) the Liquidity Provider's willful
misconduct or negligence in determining whether documents presented hereunder
comply with the terms hereof, or (B) any breach by the Liquidity Provider of any
of the terms of this Agreement, including, but not limited to, the Liquidity
Provider's failure to make lawful payment hereunder after the delivery to it by
the Borrower of a Notice of Borrowing strictly complying with the terms and
conditions hereof.

                  (b) Neither the Liquidity Provider nor any of its officers,
employees, directors or affiliates shall be liable or responsible in any respect
for (i) any error, omission, interruption or delay in transmission, dispatch or
delivery of any message or advice, however transmitted, in connection with this
Agreement or any Notice of Borrowing delivered hereunder, or (ii) any action,
inaction or omission which may be taken by it in good faith, absent willful
misconduct or negligence (in which event the extent of the Liquidity Provider's
potential liability to the Borrower shall be limited as set forth in the
immediately preceding paragraph), in connection with this Agreement or any
Notice of Borrowing.

                  Section 7.07. Costs, Expenses and Taxes. The Borrower agrees
to pay, or cause to be paid (A) on the Effective Date and on such later date or
dates on which the Liquidity Provider shall make demand, all reasonable
out-of-pocket costs and expenses (including, without limitation, the reasonable
fees and expenses of outside counsel for the Liquidity Provider) of the
Liquidity Provider in connection with the preparation, negotiation, execution,
delivery, filing and recording of this Agreement, any other Operative Agreement
and any other documents which may be delivered in connection with this Agreement
and (B) on demand, all reasonable costs and expenses (including reasonable
counsel fees and expenses) of the Liquidity Provider in connection with (i) the
enforcement of this Agreement or any other Operative Agreement, (ii) the
modification or amendment of, or supplement to, this Agreement or any other
Operative
<PAGE>   26
                                                                              22

Agreement or such other documents which may be delivered in connection herewith
or therewith (whether or not the same shall become effective) other than
amendments requested by the Liquidity Provider or a transfer made by the
Liquidity Provider either voluntarily or as a result of the mitigation
provisions of Article 3 or a Non-Extension Drawing or a Downgrade Drawing or
(iii) any action or proceeding relating to any order, injunction, or other
process or decree restraining or seeking to restrain the Liquidity Provider from
paying any amount under this Agreement, the Intercreditor Agreement or any other
Operative Agreement or otherwise affecting the application of funds in the Class
B Cash Collateral Accounts. In addition, the Borrower shall pay any and all
recording, stamp and other similar taxes and fees payable or determined to be
payable in connection with the execution, delivery, filing and recording of this
Agreement, any other Operative Agreement and such other documents, other than
amendments requested by the Liquidity Provider or a transfer made by the
Liquidity Provider either voluntarily or as a result of the mitigation
provisions of Article 3 or a Non-Extension Drawing or a Downgrade Drawing, and
agrees to save the Liquidity Provider harmless from and against any and all
liabilities with respect to or resulting from any delay in paying or omission to
pay such taxes or fees.

                  Section 7.08. Binding Effect; Participations. (a) This
Agreement shall be binding upon and inure to the benefit of the Borrower and the
Liquidity Provider and their respective successors and assigns, except that
neither the Liquidity Provider (except as otherwise provided in this Section
7.08) nor (except as contemplated by Section 3.08) the Borrower shall have the
right to assign its rights or obligations hereunder or any interest herein
without the prior written consent of the other party, subject to the
requirements of Section 7.08(b). The Liquidity Provider may grant participations
herein or in any of its rights hereunder (including, without limitation, funded
participations and participations in rights to receive interest payments
hereunder) and under the other Operative Agreements to such Persons as the
Liquidity Provider may in its sole discretion select, subject to the
requirements of Section 7.08(b). No such participation by the Liquidity
Provider, however, will relieve the Liquidity Provider of its obligations
hereunder. In connection with any participation or any proposed participation,
the Liquidity Provider may disclose to the participant or the proposed
participant any information that the Borrower is required to deliver or to
disclose to the Liquidity Provider pursuant to this Agreement. The Borrower
acknowledges and agrees that the Liquidity Provider's source of funds may derive
in part from its participants (other than America West). Accordingly, references
in this Agreement and the other Operative Agreements to determinations, reserve
and capital adequacy requirements, increased costs, reduced receipts, additional
amounts due pursuant to Section 3.03 and the like as they pertain to the
Liquidity Provider shall be deemed also to include those of each of its
participants (subject, in each case, to the maximum amount that would have been
incurred by or attributable to the Liquidity Provider directly if the Liquidity
Provider, rather than the participant, had held the interest participated).

                  (b) If, pursuant to subsection (a) above, the Liquidity
Provider sells any participation in this Agreement to any bank or other entity
(each, a "Transferee"), then, concurrently with the effectiveness of such
participation, the Transferee shall (i) represent to the Liquidity Provider (for
the benefit of the Liquidity Provider and the Borrower) either (A) that it is
incorporated under the laws of the United States or a state thereof or (B) that
under applicable law and treaties, no taxes will be required to be withheld with
respect to any payments to be made to such Transferee in respect of this
Agreement, (ii) furnish to the Liquidity Provider and the Borrower either (x) a
statement that it is incorporated under the laws of the United States or a
<PAGE>   27
                                                                              23

state thereof or (y) if it is not so incorporated, two copies of a properly
completed United States Internal Revenue Service Form 4224 or Form 1001, as
appropriate, or other applicable form, certificate or document prescribed by the
Internal Revenue Service certifying, in each case, such Transferee's entitlement
to a complete exemption from United States federal withholding tax in respect to
any and all payments to be made hereunder, and (iii) agree (for the benefit of
the Liquidity Provider and the Borrower) to provide the Liquidity Provider and
the Borrower a new Form 4224 or Form 1001, as appropriate, (A) on or before the
date that any such form expires or becomes obsolete or (B) after the occurrence
of any event requiring a change in the most recent form previously delivered by
it and prior to the immediately following due date of any payment by the
Borrower hereunder, certifying in the case of a Form 1001 or Form 4224 that such
Transferee is entitled to a complete exemption from United States federal
withholding tax on payments under this Agreement. Unless the Borrower has
received forms or other documents reasonably satisfactory to it (and required by
applicable law) indicating that payments hereunder are not subject to United
States federal withholding tax, the Borrower will withhold taxes as required by
law from such payments at the applicable statutory rate.

                  (c) Notwithstanding the other provisions of this Section 7.08,
the Liquidity Provider may assign and pledge all or any portion of the Advances
owing to it to any Federal Reserve Bank or the United States Treasury as
collateral security pursuant to Regulation A of the Board of Governors of the
Federal Reserve System and any Operating Circular issued by such Federal Reserve
Bank, provided that any payment in respect of such assigned Advances made by the
Borrower to the Liquidity Provider in accordance with the terms of this
Agreement shall satisfy the Borrower's obligations hereunder in respect of such
assigned Advance to the extent of such payment. No such assignment shall release
the Liquidity Provider from its obligations hereunder.

                  Section 7.09. Severability. Any provision of this Agreement
which is prohibited, unenforceable or not authorized in any jurisdiction shall,
as to such jurisdiction, be ineffective to the extent of such prohibition,
unenforceability or non-authorization without invalidating the remaining
provisions hereof or affecting the validity, enforceability or legality of such
provision in any other jurisdiction.

                  Section 7.10. GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED
BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.

                  Section 7.11. Submission to Jurisdiction; Waiver of Jury
Trial; Waiver of Immunity. (a) Each of the parties hereto hereby irrevocably and
unconditionally:

                  (i) submits for itself and its property in any legal action or
         proceeding relating to this Agreement or any other Operative Agreement,
         or for recognition and enforcement of any judgment in respect hereof or
         thereof, to the nonexclusive general jurisdiction of the courts of the
         State of New York, the courts of the United States of America for the
         Southern District of New York, and the appellate courts from any
         thereof;

                  (ii) consents that any such action or proceeding may be
         brought in such courts, and waives any objection that it may now or
         hereafter have to the venue of any
<PAGE>   28
                                                                              24

         such action or proceeding in any such court or that such action or
         proceeding was brought in an inconvenient court and agrees not to plead
         or claim the same;

                  (iii) agrees that service of process in any such action or
         proceeding may be effected by mailing a copy thereof by registered or
         certified mail (or any substantially similar form and mail), postage
         prepaid, to each party hereto at its address set forth in Section 7.02
         hereof, or at such other address of which the Liquidity Provider shall
         have been notified pursuant thereto; and

                  (iv) agrees that nothing herein shall affect the right to
         effect service of process in any other manner permitted by law or shall
         limit the right to sue in any other jurisdiction.

                  (b) THE BORROWER AND THE LIQUIDITY PROVIDER EACH HEREBY AGREE
TO WAIVE THEIR RESPECTIVE RIGHTS TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION
BASED UPON OR ARISING OUT OF THIS AGREEMENT OR ANY DEALINGS BETWEEN THEM
RELATING TO THE SUBJECT MATTER OF THIS AGREEMENT AND THE RELATIONSHIP THAT IS
BEING ESTABLISHED, including, without limitation, contract claims, tort claims,
breach of duty claims and all other common law and statutory claims. The
Borrower and the Liquidity Provider each warrant and represent that it has
reviewed this waiver with its legal counsel, and that it knowingly and
voluntarily waives its jury trial rights following consultation with such legal
counsel. THIS WAIVER IS IRREVOCABLE, AND CANNOT BE MODIFIED EITHER ORALLY OR IN
WRITING, AND THIS WAIVER SHALL APPLY TO ANY SUBSEQUENT AMENDMENTS, RENEWALS,
SUPPLEMENTS OR MODIFICATIONS TO THIS AGREEMENT.

                  (c) The Liquidity Provider hereby waives any immunity it may
have from the jurisdiction of the courts of the United States or of any State
and waives any immunity any of its properties located in the United States may
have from attachment or execution upon a judgment entered by any such court
under the United States Foreign Sovereign Immunities Act of 1976 or any similar
successor legislation.

                  Section 7.12. Execution in Counterparts. This Agreement may be
executed in any number of counterparts and by different parties hereto on
separate counterparts, each of which counterparts, when so executed and
delivered, shall be deemed to be an original and all of which counterparts,
taken together, shall constitute but one and the same Agreement.

                  Section 7.13. Entirety. This Agreement, the Intercreditor
Agreement and the other Operative Agreements to which the Liquidity Provider is
a party constitute the entire agreement of the parties hereto with respect to
the subject matter hereof and supersedes all prior understandings and agreements
of such parties.

                  Section 7.14. Headings. Section headings in this Agreement are
included herein for convenience of reference only and shall not constitute a
part of this Agreement for any other purpose.
<PAGE>   29
                                                                              25

                  Section 7.15. Transfer. The Liquidity Provider hereby
acknowledges and consents to the Transfer contemplated by the Assignment and
Assumption Agreement.

                  Section 7.16. LIQUIDITY PROVIDER'S OBLIGATION TO MAKE
ADVANCES. EXCEPT AS EXPRESSLY SET FORTH IN THIS AGREEMENT, THE OBLIGATIONS OF
THE LIQUIDITY PROVIDER TO MAKE ADVANCES HEREUNDER, AND THE BORROWER'S RIGHTS TO
DELIVER NOTICES OF BORROWING REQUESTING THE MAKING OF ADVANCES HEREUNDER, SHALL
BE UNCONDITIONAL AND IRREVOCABLE, AND SHALL BE PAID OR PERFORMED, IN EACH CASE
STRICTLY IN ACCORDANCE WITH THE TERMS OF THIS AGREEMENT.
<PAGE>   30
                  IN WITNESS WHEREOF, the parties have caused this Agreement to
be duly executed and delivered by their respective officers thereunto duly
authorized as of the date first set forth above.

                            WILMINGTON TRUST COMPANY,
                                   not in its individual capacity but solely as
                                   Subordination Agent, as agent and trustee for
                                   the Class B Trust, as Borrower



                                    By:  /s/ Jill K. Morrison
                                       ------------------------------------
                                       Name:  Jill K. Morrison
                                       Title: Administrative Account Manager


                                    ABN AMRO BANK N.V., Chicago Branch
                                    as Liquidity Provider



                                    By:  /s/ Claudia C. Heldring
                                       ------------------------------------
                                       Name:  Claudia C. Heldring
                                       Title: Vice President



                                    By:  /s/ Carla S. Waggoner
                                       ------------------------------------
                                       Name:  Carla S. Waggoner
                                       Title: Assistant Vice President
<PAGE>   31
                                                                      Annex I to
                                                      Revolving Credit Agreement


                      INTEREST ADVANCE NOTICE OF BORROWING

                  The undersigned, a duly authorized signatory of the
undersigned borrower (the "Borrower"), hereby certifies to ABN AMRO BANK, N.V.,
Chicago Branch (the "Liquidity Provider"), with reference to the Revolving
Credit Agreement (1998-1B) dated as of October 6, 1998, between the Borrower and
the Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and
not otherwise defined herein being used herein as therein defined or
referenced), that:

                  (1) The Borrower is the Subordination Agent under the
         Intercreditor Agreement.

                  (2) The Borrower is delivering this Notice of Borrowing for
         the making of an Interest Advance by the Liquidity Provider to be used,
         subject to clause (3)(v) below, for the payment of interest on the
         Class B Certificates which was payable on ____________, ____ (the
         "Distribution Date") in accordance with the terms and provisions of the
         Class B Trust Agreement and the Class B Certificates, which Advance is
         requested to be made on the date hereof.

                  (3) The amount of the Interest Advance requested hereby (i) is
         $_______________.__, to be applied in respect of the payment of the
         interest which was due and payable on the Class B Certificates on the
         Distribution Date, (ii) does not include any amount with respect to the
         payment of principal of, or premium on, the Class A Certificates, the
         Class B Certificates or the Class C Certificates, or interest on the
         Class A Certificates or the Class C Certificates, (iii) was computed in
         accordance with the provisions of the Class B Certificates, the Class B
         Trust Agreement and the Intercreditor Agreement (a copy of which
         computation is attached hereto as Schedule I), (iv) does not exceed the
         Maximum Available Commitment on the date hereof, (v) does not include
         any amount of interest which was due and payable on the Class B
         Certificates on such Distribution Date but which remains unpaid due to
         the failure of the Depositary to pay any amount of accrued interest on
         the Deposits on such Distribution Date and (vi) has not been and is not
         the subject of a prior or contemporaneous Notice of Borrowing.

                  (4) Upon receipt by or on behalf of the Borrower of the amount
         requested hereby, (a) the Borrower will apply the same in accordance
         with the terms of Section 3.6(b) of the Intercreditor Agreement, (b) no
         portion of such amount shall be applied by the Borrower for any other
         purpose and (c) no portion of such amount until so applied shall be
         commingled with other funds held by the Borrower.

                  The Borrower hereby acknowledges that, pursuant to the
Liquidity Agreement, the making of the Interest Advance as requested by this
Notice of Borrowing shall automatically reduce, subject to reinstatement in
accordance with the terms of the Liquidity Agreement, the Maximum Available
Commitment by an amount equal to the amount of the Interest Advance

                                      I-1
<PAGE>   32
requested to be made hereby as set forth in clause (i) of paragraph (3) of this
Certificate and such reduction shall automatically result in corresponding
reductions in the amounts available to be borrowed pursuant to a subsequent
Advance.

                  IN WITNESS WHEREOF, the Borrower has executed and delivered
this Notice of Borrowing as of the ____ day of _________, ____.


                            WILMINGTON TRUST COMPANY,
                                   not in its individual capacity but solely as
                                   Subordination Agent, as Borrower


                                            By:_________________________________
                                                 Name:
                                                 Title:

                                      I-2
<PAGE>   33
               SCHEDULE I TO INTEREST ADVANCE NOTICE OF BORROWING

[Insert Copy of Computations in accordance with Interest Advance Notice of
Borrowing]

                                      I-3
<PAGE>   34
                                                                     Annex II to
                                                      Revolving Credit Agreement

                    NON-EXTENSION ADVANCE NOTICE OF BORROWING

                  The undersigned, a duly authorized signatory of the
undersigned subordination agent (the "Borrower"), hereby certifies to ABN AMRO
BANK N.V., Chicago Branch (the "Liquidity Provider"), with reference to the
Revolving Credit Agreement (1998-1B) dated as of October 6, 1998, between the
Borrower and the Liquidity Provider (the "Liquidity Agreement"; the terms
defined therein and not otherwise defined herein being used herein as therein
defined or referenced), that:

                  (1) The Borrower is the Subordination Agent under the
         Intercreditor Agreement.

                  (2) The Borrower is delivering this Notice of Borrowing for
         the making of the Non-Extension Advance by the Liquidity Provider to be
         used for the funding of the Class B Cash Collateral Account in
         accordance with Section 3.6(d) of the Intercreditor Agreement, which
         Advance is requested to be made on __________, ____.

                  (3) The amount of the Non-Extension Advance requested hereby
         (i) is $______________, which equals the Maximum Available Commitment
         on the date hereof and is to be applied in respect of the funding of
         the Class B Cash Collateral Account in accordance with Section 3.6(d)
         of the Intercreditor Agreement, (ii) does not include any amount with
         respect to the payment of the principal of, or premium on, the Class B
         Certificates, or principal of, or interest or premium on, the Class A
         Certificates or the Class C Certificates, (iii) was computed in
         accordance with the provisions of the Class B Certificates, the Class B
         Trust Agreement and the Intercreditor Agreement (a copy of which
         computation is attached hereto as Schedule I), and (iv) has not been
         and is not the subject of a prior or contemporaneous Notice of
         Borrowing under the Liquidity Agreement.

                  (4) Upon receipt by or on behalf of the Borrower of the amount
         requested hereby, (a) the Borrower will deposit such amount in the
         Class B Cash Collateral Account and apply the same in accordance with
         the terms of Section 3.6(d) of the Intercreditor Agreement, (b) no
         portion of such amount shall be applied by the Borrower for any other
         purpose and (c) no portion of such amount until so applied shall be
         commingled with other funds held by the Borrower.

                  The Borrower hereby acknowledges that, pursuant to the
Liquidity Agreement, (A) the making of the Non-Extension Advance as requested by
this Notice of Borrowing shall automatically and irrevocably terminate the
obligation of the Liquidity Provider to make further Advances under the
Liquidity Agreement; and (B) following the making by the Liquidity Provider of
the Non-Extension Advance requested by this Notice of Borrowing, the Borrower
shall not be entitled to request any further Advances under the Liquidity
Agreement.

                                      II-1
<PAGE>   35
                  IN WITNESS WHEREOF, the Borrower has executed and delivered
this Notice of Borrowing as of the ____ day of _________, ____.


                                       WILMINGTON TRUST COMPANY,
                                             not in its individual capacity but
                                             solely as Subordination Agent, as
                                             Borrower

                                       By:_________________________________
                                            Name:
                                            Title:

                                      II-2
<PAGE>   36
             SCHEDULE I TO NON-EXTENSION ADVANCE NOTICE OF BORROWING

[Insert Copy of computations in accordance with Non-Extension Advance Notice of
Borrowing]

                                      II-3
<PAGE>   37
                                                                    Annex III to
                                                      Revolving Credit Agreement

                      DOWNGRADE ADVANCE NOTICE OF BORROWING

                  The undersigned, a duly authorized signatory of the
undersigned subordination agent (the "Borrower"), hereby certifies to ABN AMRO
BANK N.V., Chicago Branch (the "Liquidity Provider"), with reference to the
Revolving Credit Agreement (1998-1B) dated as of October 6, 1998, between the
Borrower and the Liquidity Provider (the "Liquidity Agreement"; the terms
defined therein and not otherwise defined herein being used herein as therein
defined or referenced), that:

                  (1) The Borrower is the Subordination Agent under the
         Intercreditor Agreement.

                  (2) The Borrower is delivering this Notice of Borrowing for
         the making of the Downgrade Advance by the Liquidity Provider to be
         used for the funding of the Class B Cash Collateral Account in
         accordance with Section 3.6(c) of the Intercreditor Agreement by reason
         of the downgrading of the short-term unsecured debt rating of the
         Liquidity Provider issued by either Rating Agency below the Threshold
         Rating, which Advance is requested to be made on __________, ____.

                  (3) The amount of the Downgrade Advance requested hereby (i)
         is $________________, which equals the Maximum Available Commitment on
         the date hereof and is to be applied in respect of the funding of the
         Class B Cash Collateral Account in accordance with Section 3.6(c) of
         the Intercreditor Agreement, (ii) does not include any amount with
         respect to the payment of the principal of, or premium on, the Class B
         Certificates, or principal of, or interest or premium on, the Class A
         Certificates or the Class C Certificates, (iii) was computed in
         accordance with the provisions of the Class B Certificates, the Class B
         Trust Agreement and the Intercreditor Agreement (a copy of which
         computation is attached hereto as Schedule I), and (iv) has not been
         and is not the subject of a prior or contemporaneous Notice of
         Borrowing under the Liquidity Agreement.

                  (4) Upon receipt by or on behalf of the Borrower of the amount
         requested hereby, (a) the Borrower will deposit such amount in the
         Class B Cash Collateral Account and apply the same in accordance with
         the terms of Section 3.6(c) of the Intercreditor Agreement, (b) no
         portion of such amount shall be applied by the Borrower for any other
         purpose and (c) no portion of such amount until so applied shall be
         commingled with other funds held by the Borrower.

                  The Borrower hereby acknowledges that, pursuant to the
Liquidity Agreement, (A) the making of the Downgrade Advance as requested by
this Notice of Borrowing shall automatically and irrevocably terminate the
obligation of the Liquidity Provider to make further Advances under the
Liquidity Agreement; and (B) following the making by the Liquidity
<PAGE>   38
Provider of the Downgrade Advance requested by this Notice of Borrowing, the
Borrower shall not be entitled to request any further Advances under the
Liquidity Agreement.

                  IN WITNESS WHEREOF, the Borrower has executed and delivered
this Notice of Borrowing as of the ____ day of _________, ____.

                                      WILMINGTON TRUST COMPANY,
                                             not in its individual capacity but
                                             solely as Subordination Agent, as
                                             Borrower


                                      By:_________________________________
                                           Name:
                                           Title:
<PAGE>   39
               SCHEDULE I TO DOWNGRADE ADVANCE NOTICE OF BORROWING

[Insert Copy of computations in accordance with Downgrade Advance Notice of
Borrowing]
<PAGE>   40
                                                                     Annex IV to
                                                      Revolving Credit Agreement

                        FINAL ADVANCE NOTICE OF BORROWING

                  The undersigned, a duly authorized signatory of the
undersigned borrower (the "Borrower"), hereby certifies to ABN AMRO BANK N.V.,
Chicago Branch (the "Liquidity Provider"), with reference to the Revolving
Credit Agreement (1998-1B) dated as of October 6, 1998, between the Borrower and
the Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and
not otherwise defined herein being used herein as therein defined or
referenced), that:

                  (1) The Borrower is the Subordination Agent under the
         Intercreditor Agreement.

                  (2) The Borrower is delivering this Notice of Borrowing for
         the making of the Final Advance by the Liquidity Provider to be used
         for the funding of the Class B Cash Collateral Account in accordance
         with Section 3.6(i) of the Intercreditor Agreement by reason of the
         receipt by the Borrower of a Termination Notice from the Liquidity
         Provider with respect to the Liquidity Agreement, which Advance is
         requested to be made on ____________, ____.

                  (3) The amount of the Final Advance requested hereby (i) is
         $_________________, which equals the Maximum Available Commitment on
         the date hereof and is to be applied in respect of the funding of the
         Class B Cash Collateral Account in accordance with Section 3.6(i) of
         the Intercreditor Agreement, (ii) does not include any amount with
         respect to the payment of principal of, or premium on, the Class B
         Certificates, or principal of, or interest or premium on, the Class A
         Certificates or the Class C Certificates, (iii) was computed in
         accordance with the provisions of the Class B Certificates, the Class B
         Trust Agreement and the Intercreditor Agreement (a copy of which
         computation is attached hereto as Schedule I), and (iv) has not been
         and is not the subject of a prior or contemporaneous Notice of
         Borrowing.

                  (4) Upon receipt by or on behalf of the Borrower of the amount
         requested hereby, (a) the Borrower will deposit such amount in the
         Class B Cash Collateral Account and apply the same in accordance with
         the terms of Section 3.6(i) of the Intercreditor Agreement, (b) no
         portion of such amount shall be applied by the Borrower for any other
         purpose and (c) no portion of such amount until so applied shall be
         commingled with other funds held by the Borrower.

                  The Borrower hereby acknowledges that, pursuant to the
Liquidity Agreement, (A) the making of the Final Advance as requested by this
Notice of Borrowing shall automatically and irrevocably terminate the obligation
of the Liquidity Provider to make further Advances under the Liquidity
Agreement; and (B) following the making by the Liquidity Provider of the Final
Advance requested by this Notice of Borrowing, the Borrower shall not be
entitled to request any further Advances under the Liquidity Agreement.

                                      IV-1
<PAGE>   41
                  IN WITNESS WHEREOF, the Borrower has executed and delivered
this Notice of Borrowing as of the ____ day of _________, ____.

                                    WILMINGTON TRUST COMPANY,
                                             not in its individual capacity but
                                             solely as Subordination Agent, as
                                             Borrower

                                    By:_________________________________
                                         Name:
                                         Title:
<PAGE>   42
                 SCHEDULE I TO FINAL ADVANCE NOTICE OF BORROWING

[Insert Copy of Computations in accordance with Final Advance Notice of
Borrowing]
<PAGE>   43
                                                                      Annex V to
                                                      Revolving Credit Agreement




                              NOTICE OF TERMINATION



                                     [Date]



Wilmington Trust Company,
  as Subordination Agent, as Borrower
Rodney Square North
1100 North Market Square
Wilmington, DE  19890-0001


Re:      Revolving Credit Agreement dated as of October 6, 1998, between
         Wilmington Trust Company, as Subordination Agent, as agent and trustee
         for the America West Airlines Pass Through Trust, 1998-1B-[O/S], as
         Borrower, and ABN AMRO Bank N.V., Chicago Branch, as the Liquidity
         Provider (the "Liquidity Agreement")


Ladies and Gentlemen:

                  You are hereby notified that pursuant to Section 6.01 of the
Liquidity Agreement, by reason of the occurrence of a Liquidity Event of Default
and the existence of a Performing Note Deficiency (each as defined therein), we
are giving this notice to you in order to cause (i) our obligations to make
Advances (as defined therein) under such Liquidity Agreement to terminate on the
fifth Business Day after the date on which you receive this notice and (ii) you
to request a Final Advance under the Liquidity Agreement pursuant to Section
3.6(i) of the Intercreditor Agreement (as defined in the Liquidity Agreement) as
a consequence of your receipt of this notice.

                                      V-1
<PAGE>   44
                  THIS NOTICE IS THE "NOTICE OF TERMINATION" PROVIDED FOR UNDER
THE LIQUIDITY AGREEMENT. OUR OBLIGATIONS TO MAKE ADVANCES UNDER THE LIQUIDITY
AGREEMENT WILL TERMINATE ON THE FIFTH BUSINESS DAY AFTER THE DATE ON WHICH YOU
RECEIVE THIS NOTICE.

                                            Very truly yours,

                                            ABN AMRO BANK N.V., Chicago Branch
                                                as Liquidity Provider

                                            By:_________________________________
                                                 Name:
                                                 Title:


                                            By:_________________________________
                                                 Name:
                                                 Title:
cc:      WILMINGTON TRUST COMPANY,
           as Class B Trustee

                                      V-2
<PAGE>   45
                                                                     Annex VI to
                                                      Revolving Credit Agreement

                    NOTICE OF REPLACEMENT SUBORDINATION AGENT

[Date]
Attention:

         Revolving Credit Agreement dated as of October 6, 1998, between
         WILMINGTON TRUST COMPANY, as Subordination Agent, as agent and trustee
         for the America West Airlines Pass Through Trust, 1998-1B-[O/S], as
         Borrower, and ABN AMRO Bank N.V., Chicago Branch, as the Liquidity
         Provider (the "Liquidity Agreement")


Ladies and Gentlemen:

                  For value received, the undersigned beneficiary hereby
irrevocably transfers to:

                         ------------------------------
                              [Name of Transferee]


                         ------------------------------
                             [Address of Transferee]

all rights and obligations of the undersigned as Borrower under the Liquidity
Agreement referred to above. The transferee has succeeded the undersigned as
Subordination Agent under the Intercreditor Agreement referred to in the first
paragraph of the Liquidity Agreement, pursuant to the terms of Section 8.1 of
the Intercreditor Agreement.

                  By this transfer, all rights of the undersigned as Borrower
under the Liquidity Agreement are transferred to the transferee and the
transferee shall hereafter have the sole rights and obligations as Borrower
thereunder. The undersigned shall pay any costs and expenses of such transfer,
including, but not limited to, transfer taxes or governmental charges.


                                      VI-1
<PAGE>   46
                  We ask that this transfer be effective as of _______________,
____.

                                    WILMINGTON TRUST COMPANY,
                                             not in its individual capacity but
                                             solely as Subordination Agent, as
                                             Borrower

                                    By:_________________________________
                                         Name:
                                         Title:

                                      VI-2

<PAGE>   1
                                                                       EXECUTION

                           REVOLVING CREDIT AGREEMENT
                                    (1998-1C)

                           Dated as of October 6, 1998

                                     between

                            WILMINGTON TRUST COMPANY,

                    not in its individual capacity but solely
                             as Subordination Agent,
                          as agent and trustee for the
                America West Airlines Pass Through Trust 1998-1C

                                   as Borrower

                                       and

                       ABN AMRO BANK N.V., CHICAGO BRANCH

                              as Liquidity Provider

                                   Relating to

                America West Airlines Pass Through Trust 1998-1C
             7.84% America West Airlines Pass Through Certificates,
                                 Series 1998-1C
<PAGE>   2
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                               Page
<S>                                                                                                            <C>
                                            ARTICLE I DEFINITIONS
     Section 1.01.  Certain Defined Terms. .......................................................................1

                                ARTICLE II AMOUNT AND TERMS OF THE COMMITMENT
     Section 2.01.  The Advances. ................................................................................7
     Section 2.02.  Making the Advances. .........................................................................7
     Section 2.03.  Fees. ........................................................................................8
     Section 2.04.  Reduction or Termination of the Maximum Commitment. ..........................................8
     Section 2.05.  Repayments of Interest Advances or the Final Advance. ........................................9
     Section 2.06.  Repayments of Provider Advances. .............................................................9
     Section 2.07.  Payments to the Liquidity Provider Under the Intercreditor Agreement. .......................10
     Section 2.08.  Book Entries. ...............................................................................10
     Section 2.09.  Payments from Available Funds Only. .........................................................11
     Section 2.10.  Extension of the Expiry Date; Non-Extension Advance. ........................................11

                                   ARTICLE III OBLIGATIONS OF THE BORROWER
     Section 3.01.  Increased Costs. ............................................................................12
     Section 3.02.  Capital Adequacy. ...........................................................................13
     Section 3.03.  Payments Free of Deductions. ................................................................14
     Section 3.04.  Payments. ...................................................................................14
     Section 3.05.  Computations. ...............................................................................14
     Section 3.06.  Payment on Non-Business Days. ...............................................................15
     Section 3.07.  Interest. ...................................................................................15
     Section 3.08.  Replacement of Borrower. ....................................................................16
     Section 3.09.  Funding Loss Indemnification. ...............................................................16
     Section 3.10.  Illegality. .................................................................................16

                                       ARTICLE IV CONDITIONS PRECEDENT
     Section 4.01.  Conditions Precedent to Effectiveness of Section 2.01. ......................................17
     Section 4.02.  Conditions Precedent to Borrowing. ..........................................................18

                                             ARTICLE V COVENANTS
     Section 5.01.  Affirmative Covenants of the Borrower. ......................................................18
     Section 5.02.  Negative Covenants of the Borrower. .........................................................19

                                   ARTICLE VI LIQUIDITY EVENTS OF DEFAULT
     Section 6.01.  Liquidity Events of Default. ................................................................19

                                          ARTICLE VII MISCELLANEOUS
     Section 7.01.  Amendments, Etc. ............................................................................19
     Section 7.02.  Notices, Etc. ...............................................................................20
     Section 7.03.  No Waiver; Remedies. ........................................................................20
     Section 7.04.  Further Assurances. .........................................................................21
     Section 7.05.  Indemnification; Survival of Certain Provisions. ............................................21
     Section 7.06.  Liability of the Liquidity Provider. ........................................................21
</TABLE>


                                       i
<PAGE>   3
                                TABLE OF CONTENTS
                                  (CONTINUED)

<TABLE>
<CAPTION>
                                                                                                               Page
<S>                                                                                                            <C>
     Section 7.07.  Costs, Expenses and Taxes. ..................................................................21
     Section 7.08.  Binding Effect; Participations. .............................................................22
     Section 7.09.  Severability. ...............................................................................23
     Section 7.10.  Governing Law. ..............................................................................23
     Section 7.11.  Submission to Jurisdiction; Waiver of Jury Trial; Waiver of Immunity. .......................23
     Section 7.12.  Execution in Counterparts. ..................................................................24
     Section 7.13.  Entirety. ...................................................................................24
     Section 7.14.  Headings. ...................................................................................24
     Section 7.15.  Transfer. ...................................................................................25
     Section 7.16.  Liquidity Provider's Obligation To Make Advances. ...........................................25
</TABLE>


                                       ii
<PAGE>   4
                                TABLE OF CONTENTS
                                  (CONTINUED)

ANNEX I                  Interest Advance Notice of Borrowing

ANNEX II                 Non-Extension Advance Notice of Borrowing

ANNEX III                Downgrade Advance Notice of Borrowing

ANNEX IV                 Final Advance Notice of Borrowing

ANNEX V                  Notice of Termination

ANNEX VI                 Notice of Replacement Subordination Agent


                                      iii
<PAGE>   5
                           REVOLVING CREDIT AGREEMENT

                  This REVOLVING CREDIT AGREEMENT dated as of October 6, 1998,
between WILMINGTON TRUST COMPANY, a Delaware banking corporation, not in its
individual capacity but solely as Subordination Agent under the Intercreditor
Agreement (each as defined below), as agent and trustee for the Class C Trust
(as defined below) (the "Borrower"), and ABN AMRO BANK N.V., a bank organized
under the laws of the Netherlands, acting through its Chicago branch (the
"Liquidity Provider").

                              W I T N E S S E T H:

                  WHEREAS, pursuant to the Class C Trust Agreement (such term
and all other capitalized terms used in these recitals having the meanings set
forth or referred to in Section 1.01), the Class C Trust is issuing the Class C
Certificates; and

                  WHEREAS, the Borrower, in order to support the timely payment
of a portion of the interest on the Class C Certificates in accordance with
their terms, has requested the Liquidity Provider to enter into this Agreement,
providing in part for the Borrower to request in specified circumstances that
Advances be made hereunder.

                  NOW, THEREFORE, in consideration of the premises, the parties
hereto agree as follows:

                                    ARTICLE I

                                   DEFINITIONS

                  Section 1.01. Certain Defined Terms. (a) Definitions. As used
in this Agreement and unless otherwise expressly indicated, or unless the
context clearly requires otherwise, the following capitalized terms shall have
the following respective meanings for all purposes of this Agreement:

                  "Additional Cost" has the meaning assigned to such term in
         Section 3.01.

                  "Advance" means an Interest Advance, a Final Advance, a
         Provider Advance, an Applied Provider Advance or an Unpaid Advance, as
         the case may be.

                  "Applicable Liquidity Rate" has the meaning assigned to such
         term in Section 3.07(g).

                  "Applicable Margin" means (A) with respect to any Unpaid
         Advance or Applied Provider Advance, (x) with respect to any LIBOR
         Advance, 1.75% and (y) with respect to any Base Rate Advance, 1%, and
         (B) with respect to any Unapplied Provider Advance, (x) with respect to
         any LIBOR Advance, .35% and (y) with respect to any Base Rate Advance,
         0.
<PAGE>   6
                                                                               2


                  "Applied Downgrade Advance" has the meaning assigned to such
         term in Section 2.06(a).

                  "Applied Non-Extension Advance" has the meaning assigned to
         such term in Section 2.06(a).

                  "Applied Provider Advance" has the meaning assigned to such
         term in Section 2.06(a).

                  "Assignment and Assumption Agreement" means the Assignment and
         Assumption to be entered into between the Borrower and the trustee of
         the Successor Trust, substantially in the form of Exhibit D to the
         Class C Trust Agreement.

                  "Base Rate" means a fluctuating interest rate per annum in
         effect from time to time, which rate per annum shall at all times be
         equal to (a) the weighted average of the rates on overnight Federal
         funds transactions with members of the Federal Reserve System arranged
         by Federal funds brokers, as published for such day (or, if such day is
         not a Business Day, for the next preceding Business Day) by the Federal
         Reserve Bank of New York, or if such rate is not so published for any
         day that is a Business Day, the average of the quotations for such day
         for such transactions received by the Liquidity Provider from three
         Federal funds brokers of recognized standing selected by it, plus (b)
         one quarter of one percent (1/4 of 1%).

                  "Base Rate Advance" means an Advance that bears interest at a
         rate based upon the Base Rate.

                  "Borrower" has the meaning assigned to such term in the
         recital of parties to this Agreement.

                  "Borrowing" means the making of Advances requested by delivery
         of a Notice of Borrowing.

                  "Business Day" means any day other than a Saturday or Sunday
         or a day on which commercial banks are required or authorized to close
         in Phoenix, Arizona, New York, New York, Chicago, Illinois or, so long
         as any Class C Certificate is outstanding, the city and state in which
         the Class C Trustee, the Borrower or any Loan Trustee maintains its
         Corporate Trust Office or receives or disburses funds, and, if the
         applicable Business Day relates to any Advance or other amount bearing
         interest based on the LIBOR Rate, on which dealings are carried on in
         the London interbank market.

                  "Deposits" has the meaning assigned to such terms in the
         Deposit Agreement.

                  "Depositary" has the meaning assigned to such term in the
         Deposit Agreement.

                  "Deposit Agreement" means the Deposit Agreement dated October
         6, 1998 between Wilmington Trust Company, as Escrow Agent and ABN AMRO
         Bank N.V., acting through its Chicago branch, as Depositary, pertaining
         to the Class C Certificates,
<PAGE>   7
                                                                               3


         as the same may be amended, modified or supplemented from time to time
         in accordance with the terms thereof.

                  "Downgrade Advance" means an advance made pursuant to Section
         2.02(c).

                  "Effective Date" has the meaning specified in Section 4.01.
         The delivery of the certificate of the Liquidity Provider contemplated
         by Section 4.01(e) shall be conclusive evidence that the Effective Date
         has occurred.

                  "Excluded Taxes" means (i) taxes imposed on the overall net
         income, net worth, capital or franchise of the Liquidity Provider or of
         its Lending Office by the jurisdiction where such Liquidity Provider's
         principal office or such Lending Office is located, and (ii) Excluded
         Withholding Taxes.

                  "Excluded Withholding Taxes" means (i) withholding Taxes
         imposed by the United States except (but only in the case of a
         successor Liquidity Provider organized under the laws of a jurisdiction
         outside the United States) to the extent that such United States
         withholding Taxes are imposed as a result of any change in applicable
         law (excluding from change in applicable law for this purpose a change
         in an applicable treaty or other change in law affecting the
         applicability of a treaty) after the date hereof, or in the case of a
         successor Liquidity Provider (including a transferee of an Advance) or
         Lending Office, after the date on which such successor Liquidity
         Provider obtains its interest or on which the Lending Office is
         changed, and (ii) any withholding Taxes imposed by the United States
         which are imposed or increased as a result of the Liquidity Provider
         failing to deliver to the Borrower any certificate or document (which
         certificate or document in the good faith judgment of the Liquidity
         Provider it is legally entitled to provide) which is reasonably
         requested by the Borrower to establish that payments under this
         Agreement are exempt from (or entitled to a reduced rate of)
         withholding Tax.

                  "Expenses" means liabilities, obligations, damages,
         settlements, penalties, claims, actions, suits, costs, expenses, and
         disbursements (including, without limitation, reasonable fees and
         disbursements of legal counsel and costs of investigation), provided
         that Expenses shall not include any Taxes.

                  "Expiry Date" means October 4, 1999, initially, or any date to
         which the Expiry Date is extended pursuant to Section 2.10.

                  "Final Advance" means an advance made pursuant to Section
         2.02(d).

                  "Intercreditor Agreement" means the Intercreditor Agreement
         dated the date hereof, among the Trustees, the Liquidity Provider, the
         liquidity provider under each Liquidity Facility (other than this
         Agreement) and the Subordination Agent, as the same may be amended,
         supplemented or otherwise modified from time to time in accordance with
         its terms.

                  "Interest Advance" means an advance made pursuant to Section
         2.02(a).
<PAGE>   8
                                                                               4


                  "Interest Period" means, with respect to any LIBOR Advance,
         each of the following periods:

                  (i)      the period beginning on the third Business Day
                           following either (x) the Liquidity Provider's receipt
                           of the Notice of Borrowing for such LIBOR Advance
                           (or, in the case of an Unapplied Downgrade Advance,
                           the period beginning on the Expiry Date) or (y) the
                           withdrawal of funds from the Class C Cash Collateral
                           Account for the purpose of paying interest on the
                           Class C Certificates as contemplated by Section
                           2.06(a) hereof and, in either case, ending on the
                           next Regular Distribution Date; and

                  (ii)     each subsequent period commencing on the last day of
                           the immediately preceding Interest Period and ending
                           on the next Regular Distribution Date;

         provided, however, that if (x) the Final Advance shall have been made,
         or (y) other outstanding Advances shall have been converted into the
         Final Advance, then the Interest Periods shall be successive periods of
         one month beginning on the third Business Day following the Liquidity
         Provider's receipt of the Notice of Borrowing for such Final Advance
         (in the case of clause (x) above) or the last day of the Interest
         Period then applicable to such outstanding Advances (in the case of
         clause (y) above).

                  "Lending Office" means the office of the Liquidity Provider in
         which it books this facility presently located at Chicago, Illinois, or
         such other office as the Liquidity Provider from time to time shall
         notify the Borrower as its "Lending Office" hereunder in which it books
         this facility; provided that the Liquidity Provider shall not change
         its Lending Office to a Lending Office outside the United States of
         America except in accordance with Section 3.01, 3.02 or 3.03 hereof.

                  "LIBOR Advance" means an Advance bearing interest at a rate
         based upon the LIBOR Rate.

                  "LIBOR Rate" means, with respect to any Interest Period, the
         rate per annum appearing on Page 3750 of the Dow Jones Markets Service
         (or any successor or substitute Page of such Service, or any successor
         to or substitute for such Service, providing rate quotations comparable
         to those currently provided on such Page applicable to deposits in
         dollars in the London interbank market) at approximately 11:00 A.M.
         (London time) two Business Days before the first day of such Interest
         Period for a period of time comparable to such Interest Period. In the
         event that such rate is not available at such time for any reason, then
         the LIBOR Rate with respect to any Interest Period shall be the rate
         per annum at which deposits in dollars are offered to major banks in
         the London interbank market at approximately 11:00 A.M. (London time)
         two Business Days before the first day of such Interest Period for a
         period of time comparable to such Interest Period.

                  "Liquidity Event of Default" means the occurrence of either
         (a) the Acceleration of all of the Equipment Notes (provided that, with
         respect to the period prior to the Delivery Period Expiry Date, such
         Equipment Notes have an aggregate outstanding principal balance in
         excess of $125,000,000) or (b) an America West Bankruptcy Event.
<PAGE>   9
                                                                               5


                  "Liquidity Indemnitee" means (i) the Liquidity Provider, (ii)
         the directors, officers, employees and agents of the Liquidity
         Provider, and (iii) the successors and permitted assigns of the persons
         described in clauses (i) and (ii), inclusive.

                  "Liquidity Provider" has the meaning assigned to such term in
         the recital of parties to this Agreement.

                  "Maximum Available Commitment" means, subject to the proviso
         contained in the third sentence of Section 2.02(a), at any time of
         determination, (a) the Maximum Commitment at such time less (b) the
         aggregate amount of each Interest Advance outstanding at such time;
         provided that following a Provider Advance or a Final Advance, the
         Maximum Available Commitment shall be zero.

                  "Maximum Commitment" means initially $2,214,896, as the same
         may be reduced from time to time in accordance with Section 2.04(a).

                  "Non-Extension Advance" means an advance made pursuant to
         Section 2.02(b).

                  "Notice of Borrowing" has the meaning specified in Section
         2.02(e).

                  "Notice of Replacement Subordination Agent" has the meaning
         specified in Section 3.08.

                  "Offering Memorandum" means the Offering Memorandum dated
         September 24, 1998 relating to the Certificates, as such Offering
         Memorandum may be amended or supplemented.

                  "Performing Note Deficiency" means any time that less than 65%
         of the then aggregate outstanding principal amount of all Equipment
         Notes are Performing Equipment Notes.

                  "Provider Advance" means a Downgrade Advance or a
         Non-Extension Advance.

                  "Regulatory Change" has the meaning assigned to such term in
         Section 3.01.

                  "Replenishment Amount" has the meaning assigned to such term
         in Section 2.06(b).

                  "Required Amount" means, for any day, the sum of the aggregate
         amount of interest, calculated at the rate per annum equal to the
         Stated Interest Rate for the Class C Certificates, that would be
         payable on the Class C Certificates on each of the three successive
         semiannual Regular Distribution Dates immediately following such day
         or, if such day is a Regular Distribution Date, on such day and the
         succeeding two semiannual Regular Distribution Dates, in each case
         calculated on the basis of the Pool Balance of the Class C Certificates
         on such day and without regard to expected future payments of principal
         on the Class C Certificates.
<PAGE>   10
                                                                               6


                  "Successor Trust" means America West Airlines Pass Through
         Trust 1998-1C-S.

                  "Termination Date" means the earliest to occur of the
         following: (i) the Expiry Date; (ii) the date on which the Borrower
         delivers to the Liquidity Provider a certificate, signed by a
         Responsible Officer of the Borrower, certifying that all of the Class C
         Certificates have been paid in full (or provision has been made for
         such payment in accordance with the Intercreditor Agreement and the
         Trust Agreements) or are otherwise no longer entitled to the benefits
         of this Agreement; (iii) the date on which the Borrower delivers to the
         Liquidity Provider a certificate, signed by a Responsible Officer of
         the Borrower, certifying that a Replacement Liquidity Facility has been
         substituted for this Agreement in full pursuant to Section 3.6(e) of
         the Intercreditor Agreement; (iv) the fifth Business Day following the
         receipt by the Borrower of a Termination Notice from the Liquidity
         Provider pursuant to Section 6.01 hereof; and (v) the date on which no
         Advance is or may (including by reason of reinstatement as herein
         provided) become available for a Borrowing hereunder.

                  "Termination Notice" means the Notice of Termination
         substantially in the form of Annex V to this Agreement.

                  "Transferee" has the meaning assigned to such term in Section
         7.08(b).

                  "Unapplied Downgrade Advance" means any Downgrade Advance
         other than an Applied Downgrade Advance.

                  "Unapplied Provider Advance" means any Provider Advance other
         than an Applied Provider Advance.

                  "Unpaid Advance" has the meaning assigned to such term in
         Section 2.05.

                  (b) Terms Defined in the Intercreditor Agreement. For all
purposes of this Agreement, the following terms shall have the respective
meanings assigned to such terms in the Intercreditor Agreement:

         "Acceleration", "America West", "America West Bankruptcy Event",
         "Certificates", "Class A Certificates", "Class B Certificates", "Class
         C Cash Collateral Account", "Class C Certificates", "Class C
         Certificateholders", "Class C Trust", "Class C Trust Agreement", "Class
         C Trustee", "Closing Date", "Controlling Party", "Corporate Trust
         Office", "Delivery Period Expiry Date", "Distribution Date",
         "Downgraded Facility", "Equipment Notes", "Fee Letter", "Final Legal
         Distribution Date", "Financing Agreement", "Indenture", "Initial
         Purchasers", "Interest Payment Date", "Investment Earnings", "Liquidity
         Facility", "Liquidity Obligations", "Loan Trustee", "Moody's",
         "Non-Extended Facility", "Note Purchase Agreement", "Operative
         Agreements", "Performing Equipment Note", "Person", "Pool Balance",
         "Purchase Agreement", "Rating Agency", "Ratings Confirmation", "Regular
         Distribution Date", "Replacement Liquidity Facility", "Responsible
         Officer", "Scheduled Payment", "Special Payment", "Standard & Poor's",
         "Stated Interest Rate", "Subordination Agent", "Taxes", "Threshold
         Rating", "Transfer", "Trust Agreements", "Trustee", and "Written
         Notice".
<PAGE>   11
                                                                               7


                                   ARTICLE II

                       AMOUNT AND TERMS OF THE COMMITMENT

                  Section 2.01. The Advances. The Liquidity Provider hereby
irrevocably agrees, on the terms and conditions hereinafter set forth, to make
Advances to the Borrower from time to time on any Business Day during the period
from the Effective Date until 12:00 Noon (New York City time) on the Expiry Date
(unless the obligations of the Liquidity Provider shall be earlier terminated in
accordance with the terms of Section 2.04(b)) in an aggregate amount at any time
outstanding not to exceed the Maximum Commitment.

                  Section 2.02. Making the Advances. (a) Interest Advances shall
be made in one or more Borrowings by delivery to the Liquidity Provider of one
or more written and completed Notices of Borrowing in substantially the form of
Annex I attached hereto, signed by a Responsible Officer of the Borrower, in an
amount not exceeding the Maximum Available Commitment at such time and shall be
used solely for the payment when due of interest on the Class C Certificates at
the Stated Interest Rate therefor in accordance with Section 3.6(a) of the
Intercreditor Agreement. Each Interest Advance made hereunder shall
automatically reduce the Maximum Available Commitment by the amount of such
Interest Advance (subject to reinstatement as provided in the next sentence).
Upon repayment to the Liquidity Provider in full of the amount of any Interest
Advance made pursuant to this Section 2.02(a), together with accrued interest
thereon (as provided herein), the Maximum Available Commitment shall be
reinstated by the amount of such repaid Interest Advance, but not to exceed the
Maximum Commitment; provided, however, that the Maximum Available Commitment
shall not be so reinstated at any time if (i) a Liquidity Event of Default shall
have occurred and be continuing and (ii) there is a Performing Note Deficiency.

                  (b) A Non-Extension Advance shall be made in a single
Borrowing if this Agreement is not extended in accordance with Section 3.6(d) of
the Intercreditor Agreement (unless a Replacement Liquidity Facility to replace
this Agreement shall have been delivered to the Borrower as contemplated by said
Section 3.6(d) within the time period specified in such Section) by delivery to
the Liquidity Provider of a written and completed Notice of Borrowing in
substantially the form of Annex II attached hereto, signed by a Responsible
Officer of the Borrower, in an amount equal to the Maximum Available Commitment
at such time, and shall be used to fund the Class C Cash Collateral Account in
accordance with said Section 3.6(d) and Section 3.6(f) of the Intercreditor
Agreement.

                  (c) A Downgrade Advance shall be made in a single Borrowing
upon a downgrading of the Liquidity Provider's short-term unsecured debt rating
issued by either Rating Agency below the applicable Threshold Rating (as
provided for in Section 3.6(c) of the Intercreditor Agreement) unless a
Replacement Liquidity Facility to replace this Agreement shall have been
previously delivered to the Borrower in accordance with said Section 3.6(c), by
delivery to the Liquidity Provider of a written and completed Notice of
Borrowing in substantially the form of Annex III attached hereto, signed by a
Responsible Officer of the Borrower, in an amount equal to the Maximum Available
Commitment at such time, and shall be used to fund the Class C Cash Collateral
Account in accordance with said Section 3.6(c) and Section 3.6(f) of the
Intercreditor Agreement.
<PAGE>   12
                                                                               8


                  (d) A Final Advance shall be made in a single Borrowing upon
the receipt by the Borrower of a Termination Notice from the Liquidity Provider
pursuant to Section 6.01 hereof by delivery to the Liquidity Provider of a
written and completed Notice of Borrowing in substantially the form of Annex IV
attached hereto, signed by a Responsible Officer of the Borrower, in an amount
equal to the Maximum Available Commitment at such time, and shall be used to
fund the Class C Cash Collateral Account (in accordance with Section 3.6(i) of
the Intercreditor Agreement) and Section 3.6(f) of the Intercreditor Agreement.

                  (e) Each Borrowing shall be made on notice in writing (a
"Notice of Borrowing") in substantially the form required by Section 2.02(a),
2.02(b), 2.02(c) or 2.02(d), as the case may be, given by the Borrower to the
Liquidity Provider. If a Notice of Borrowing is delivered by the Borrower in
respect of any Borrowing no later than 1:00 p.m. (New York City time) on a
Business Day, upon satisfaction of the conditions precedent set forth in Section
4.02 with respect to a requested Borrowing, the Liquidity Provider shall make
available to the Borrower, in accordance with its payment instructions, the
amount of such Borrowing in U.S. dollars and immediately available funds, before
3:00 p.m. (New York City time) on such Business Day or on such later Business
Day specified in such Notice of Borrowing. If a Notice of Borrowing is delivered
by the Borrower in respect of any Borrowing after 1:00 p.m. (New York City time)
on a Business Day, upon satisfaction of the conditions precedent set forth in
Section 4.02 with respect to a requested Borrowing, the Liquidity Provider shall
make available to the Borrower, in accordance with its payment instructions, the
amount of such Borrowing in U.S. dollars and immediately available funds, before
12:00 Noon (New York City time) on the first Business Day next following the day
of receipt of such Notice of Borrowing or on such later Business Day specified
by the Borrower in such Notice of Borrowing. Payments of proceeds of a Borrowing
shall be made by wire transfer of immediately available funds to the Borrower in
accordance with such wire transfer instructions as the Borrower shall furnish
from time to time to the Liquidity Provider for such purpose. Each Notice of
Borrowing shall be irrevocable and binding on the Borrower.

                  (f) Upon the making of any Advance requested pursuant to a
Notice of Borrowing, in accordance with the Borrower's payment instructions, the
Liquidity Provider shall be fully discharged of its obligation hereunder with
respect to such Notice of Borrowing, and the Liquidity Provider shall not
thereafter be obligated to make any further Advances hereunder in respect of
such Notice of Borrowing to the Borrower or to any other Person. Following the
making of any Advance pursuant to Section 2.02(b), (c) or (d) hereof to fund the
Class C Cash Collateral Account, the Liquidity Provider shall have no interest
in or rights to the Class C Cash Collateral Account, such Advance or any other
amounts from time to time on deposit in the Class C Cash Collateral Account;
provided that the foregoing shall not affect or impair the obligations of the
Subordination Agent to make the distributions contemplated by Section 3.6(e) or
(f) of the Intercreditor Agreement. By paying to the Borrower proceeds of
Advances requested by the Borrower in accordance with the provisions of this
Agreement, the Liquidity Provider makes no representation as to, and assumes no
responsibility for, the correctness or sufficiency for any purpose of the amount
of the Advances so made and requested.

                  Section 2.03. Fees. The Borrower agrees to pay to the
Liquidity Provider the fees set forth in the Fee Letter.

                  Section 2.04. Adjustments or Termination of the Maximum
Commitment.
<PAGE>   13
                                                                               9


                  (a) Automatic Adjustments. Promptly following each date on
which the Required Amount is (1) reduced as a result of a reduction in the Pool
Balance of the Class C Certificates or otherwise, (2) increased as a result of
an increase in the Stated Interest Rate or (3) subsequent to such an increase
described in clause (2), reduced pursuant to the definition of "Stated Interest
Rate", the Maximum Commitment shall automatically be reduced or increased, as
the case may be, to an amount equal to the Required Amount (as calculated by the
Borrower). The Borrower shall give notice of any such automatic reduction or
increase, as the case may be, of the Maximum Commitment to the Liquidity
Provider within two Business Days thereof. The failure by the Borrower to
furnish any such notice shall not affect such automatic reduction or increase of
the Maximum Commitment.

                  (b) Termination. Upon the making of any Provider Advance or
Final Advance hereunder or the occurrence of the Termination Date, the
obligation of the Liquidity Provider to make further Advances hereunder shall
automatically and irrevocably terminate, and the Borrower shall not be entitled
to request any further Borrowing hereunder.

                  Section 2.05. Repayments of Interest Advances or the Final
Advance. Subject to Sections 2.06, 2.07 and 2.09 hereof, the Borrower hereby
agrees, without notice of an Advance or demand for repayment from the Liquidity
Provider (which notice and demand are hereby waived by the Borrower), to pay, or
to cause to be paid, to the Liquidity Provider on each date on which the
Liquidity Provider shall make an Interest Advance or the Final Advance, an
amount equal to (a) the amount of such Advance (any such Advance, until repaid,
is referred to herein as an "Unpaid Advance"), plus (b) interest on the amount
of each such Unpaid Advance as provided in Section 3.07 hereof; provided that if
(i) the Liquidity Provider shall make a Provider Advance at any time after
making one or more Interest Advances which shall not have been repaid in
accordance with this Section 2.05 or (ii) this Liquidity Facility shall become a
Downgraded Facility or Non-Extended Facility at any time when unreimbursed
Interest Advances have reduced the Maximum Available Commitment to zero, then
such Interest Advances shall cease to constitute Unpaid Advances and shall be
deemed to have been changed into an Applied Downgrade Advance or an Applied
Non-Extension Advance, as the case may be, for all purposes of this Agreement
(including, without limitation, for the purpose of determining when such
Interest Advance is required to be repaid to the Liquidity Provider in
accordance with Section 2.06 and for the purposes of Section 2.06(b)). The
Borrower and the Liquidity Provider agree that the repayment in full of each
Interest Advance and Final Advance on the date such Advance is made is intended
to be a contemporaneous exchange for new value given to the Borrower by the
Liquidity Provider.

                  Section 2.06. Repayments of Provider Advances. (a) Amounts
advanced hereunder in respect of a Provider Advance shall be deposited in the
Class C Cash Collateral Account, invested and withdrawn from the Class C Cash
Collateral Account as set forth in Sections 3.6(c), (d) and (f) of the
Intercreditor Agreement. The Borrower agrees to pay to the Liquidity Provider,
on each Regular Distribution Date, commencing on the first Regular Distribution
Date after the making of a Provider Advance, interest on the principal amount of
any such Provider Advance as provided in Section 3.07; provided, however, that
amounts in respect of a Provider Advance withdrawn from the Class C Cash
Collateral Account for the purpose of paying interest on the Class C
Certificates in accordance with Section 3.6(f) of the Intercreditor Agreement
(the amount of any such withdrawal being (y) in the case of a
<PAGE>   14
                                       10


Downgrade Advance, an "Applied Downgrade Advance" and (z) in the case of a
Non-Extension Advance, an "Applied Non-Extension Advance" and, together with an
Applied Downgrade Advance, an "Applied Provider Advance") shall thereafter
(subject to Section 2.06(b)) be treated as an Interest Advance under this
Agreement for purposes of determining the Applicable Liquidity Rate for interest
payable thereon; provided further, however, that if, following the making of a
Provider Advance, the Liquidity Provider delivers a Termination Notice to the
Borrower pursuant to Section 6.01 hereof, such Provider Advance shall thereafter
be treated as a Final Advance under this Agreement for purposes of determining
the Applicable Liquidity Rate for interest payable thereon. Subject to Sections
2.07 and 2.09 hereof, immediately upon the withdrawal of any amounts from the
Class C Cash Collateral Account on account of a reduction in the Required
Amount, the Borrower shall repay to the Liquidity Provider a portion of the
Provider Advances in a principal amount equal to such reduction, plus interest
on the principal amount prepaid as provided in Section 3.07 hereof.

                  (b) At any time when an Applied Provider Advance (or any
portion thereof) is outstanding, upon the deposit in the Class C Cash Collateral
Account of any amount pursuant to clause "third" of Section 2.4(b) of the
Intercreditor Agreement, clause "third" of Section 3.2 of the Intercreditor
Agreement or clause "fourth" of Section 3.3 of the Intercreditor Agreement (any
such amount being a "Replenishment Amount") for the purpose of replenishing or
increasing the balance thereof up to the Required Amount at such time, (i) the
aggregate outstanding principal amount of all Applied Provider Advances (and of
Provider Advances treated as an Interest Advance for purposes of determining the
Applicable Liquidity Rate for interest payable thereon) shall be automatically
reduced by the amount of such Replenishment Amount and (ii) the aggregate
outstanding principal amount of all Unapplied Provider Advances shall be
automatically increased by the amount of such Replenishment Amount.

                  (c) Upon the provision of a Replacement Liquidity Facility in
replacement of this Agreement in accordance with Section 3.6(e) of the
Intercreditor Agreement, amounts remaining on deposit in the Class C Cash
Collateral Account after giving effect to any Applied Provider Advance on the
date of such replacement shall be reimbursed to the Liquidity Provider, but only
to the extent such amounts are necessary to repay in full to the Liquidity
Provider all amounts owing to it hereunder.

                  Section 2.07. Payments to the Liquidity Provider Under the
Intercreditor Agreement. In order to provide for payment or repayment to the
Liquidity Provider of any amounts hereunder, the Intercreditor Agreement
provides that amounts available and referred to in Articles II and III of the
Intercreditor Agreement, to the extent payable to the Liquidity Provider
pursuant to the terms of the Intercreditor Agreement (including, without
limitation, Section 3.6(f) of the Intercreditor Agreement), shall be paid to the
Liquidity Provider in accordance with the terms thereof. Amounts so paid to the
Liquidity Provider shall be applied by the Liquidity Provider to Liquidity
Obligations then due and payable in accordance with the Intercreditor Agreement
or, if not provided for in the Intercreditor Agreement, then in such manner as
the Liquidity Provider shall deem appropriate.

                  Section 2.08. Book Entries. The Liquidity Provider shall
maintain in accordance with its usual practice an account or accounts evidencing
the indebtedness of the Borrower resulting from Advances made from time to time
and the amounts of principal and interest payable hereunder and paid from time
to time in respect thereof; provided, however, that the
<PAGE>   15
                                                                              11


failure by the Liquidity Provider to maintain such account or accounts shall not
affect the obligations of the Borrower in respect of Advances.

                  Section 2.09. Payments from Available Funds Only. All payments
to be made by the Borrower under this Agreement shall be made only from the
amounts that constitute Scheduled Payments, Special Payments or payments under
Section 7.1 or 9.1, as the case may be, of the Participation Agreements and
Section 6 of the Note Purchase Agreement and only to the extent that the
Borrower shall have sufficient income or proceeds therefrom to enable the
Borrower to make payments in accordance with the terms hereof after giving
effect to the priority of payments provisions set forth in the Intercreditor
Agreement. The Liquidity Provider agrees that it will look solely to such
amounts to the extent available for distribution to it as provided in the
Intercreditor Agreement and this Agreement and that the Borrower, in its
individual capacity, is not personally liable to it for any amounts payable or
liability under this Agreement except as expressly provided in this Agreement,
the Intercreditor Agreement or any Participation Agreement. Amounts on deposit
in the Class C Cash Collateral Account shall be available to the Borrower to
make payments under this Agreement only to the extent and for the purposes
expressly contemplated in Section 3.6(f) of the Intercreditor Agreement.

                  Section 2.10. Extension of the Expiry Date; Non-Extension
Advance. No earlier than the 60th day and no later than the 40th day prior to
the then effective Expiry Date (unless such Expiry Date is on or after the date
that is 15 days after the Final Legal Distribution Date for the Class C
Certificates), the Borrower shall request that the Liquidity Provider extend the
Expiry Date for a period of 364 days after the then effective Expiry Date
(unless the obligations of the Liquidity Provider are earlier terminated in
accordance with the terms hereof). The Liquidity Provider shall advise the
Borrower, no earlier than 40 days and no later than 25 days prior to the then
effective Expiry Date, whether, in its sole discretion, it agrees to so extend
the Expiry Date. If the Liquidity Provider advises the Borrower on or before the
25th day prior to the Expiry Date then in effect that such Expiry Date shall not
be so extended, or fails to irrevocably and unconditionally advise the Borrower
on or before the 25th day prior to the Expiry Date then in effect that such
Expiry Date shall be so extended (and, in each case, if the Liquidity Provider
shall not have been replaced in accordance with Section 3.6(e) of the
Intercreditor Agreement), the Borrower shall be entitled on and after such 25th
day (but prior to the then effective Expiry Date) to request a Non-Extension
Advance in accordance with Section 2.02(b) hereof and Section 3.6(d) of the
Intercreditor Agreement.
<PAGE>   16
                                                                              12


                                   ARTICLE III

                           OBLIGATIONS OF THE BORROWER

                  Section 3.01. Increased Costs. The Borrower shall pay to the
Liquidity Provider from time to time such amounts as may be necessary to
compensate the Liquidity Provider for any increased costs incurred by the
Liquidity Provider which are reasonably attributable to its making or
maintaining any LIBOR Advances hereunder or its obligation to make any such
Advances hereunder, or any reduction in any amount receivable by the Liquidity
Provider under this Agreement or the Intercreditor Agreement in respect of any
such Advances or such obligation (such increases in costs and reductions in
amounts receivable being herein called "Additional Costs"), resulting from any
change after the date of this Agreement in U.S. federal, state, municipal, or
foreign laws or regulations (including Regulation D of the Board of Governors of
the Federal Reserve System applicable to banks generally), or the adoption or
making after the date of this Agreement of any interpretations, directives, or
requirements applying to a class of banks including the Liquidity Provider under
any U.S. federal, state, municipal, or any foreign laws or regulations (whether
or not having the force of law but of the type with which the Liquidity Provider
is accustomed to comply) by any court, central bank or monetary authority
charged with the interpretation or administration thereof in each case not
publicly announced on the date hereof (a "Regulatory Change"), which: (1)
changes the basis of taxation of any amounts payable to the Liquidity Provider
under this Agreement in respect of any such Advances (other than Excluded
Taxes); or (2) imposes or modifies any reserve, special deposit, compulsory loan
or similar requirements relating to any extensions of credit hereunder in
respect of LIBOR Advances (including any such Advances or any deposits referred
to in the definition of LIBOR Rate or related definitions), other than (i) costs
which arise as a result of the Liquidity Provider willfully contravening or
exceeding any operating limits or other restrictions imposed on it by any
authority; or (ii) if the increased costs would not have arisen but for any
assignment to another Liquidity Provider or an alteration in the lending office
of the Liquidity Provider. The Liquidity Provider agrees to use reasonable
efforts (consistent with applicable legal and regulatory restrictions) to change
the jurisdiction of its Lending Office if making such change would avoid the
need for, or reduce the amount of, any amount payable under this Section that
may thereafter accrue and would not, in the reasonable judgment of the Liquidity
Provider, be otherwise materially disadvantageous to the Liquidity Provider.

                  The Liquidity Provider will notify the Borrower of any event
occurring after the date of this Agreement that will entitle the Liquidity
Provider to compensation pursuant to this Section 3.01 as promptly as
practicable after it obtains knowledge thereof and determines to request such
compensation, which notice shall describe in reasonable detail the calculation
of the amounts owed under this Section; provided, that if the Liquidity Provider
fails to give such notice within 30 days after it obtains such knowledge, the
Liquidity Provider shall, with respect to any costs resulting from such event,
only be entitled to payment under this Section 3.01 for costs incurred from and
after the date 30 days prior to the date the Liquidity Provider does give such
notice. Determinations by the Liquidity Provider for purposes of this Section
3.01 of the effect of any Regulatory Change on its costs of making or
maintaining Advances or on amounts receivable by it in respect of Advances, and
of the additional amounts required to compensate the Liquidity Provider in
respect of any Additional Costs, shall be prima facie evidence of the amount
owed under this Section.
<PAGE>   17
                                                                              13


                  The Liquidity Provider shall not be entitled to compensation
under this Section 3.01 if (1) it shall not be also seeking compensation (if it
should be so entitled) under other comparable contractual provisions in its
other agreements, (2) if its claim under this Section 3.01 arises through
circumstances peculiar to the Liquidity Provider and which do not affect a
similarly organized commercial banking institution in the same jurisdiction
generally, or (3) the Liquidity Provider is not the initial liquidity provider
and America West did not consent to the transfer of this facility to the
Liquidity Provider, for the amount, if any, payable under this Section 3.01
resulting from events occurring prior to the date the Liquidity Provider
acquired its interests hereunder as shall exceed the amount payable under this
Section 3.01 that would have been due to the Liquidity Provider's transferor had
it continued to be the liquidity provider hereunder.

                  Section 3.02. Capital Adequacy. If (1) the adoption, after the
date hereof, of any applicable governmental law, rule or regulation regarding
capital adequacy and not publicly announced on the date hereof, (2) any change,
after the date hereof, in the interpretation or administration of any such law,
rule or regulation by any central bank or other governmental authority charged
with the interpretation or administration thereof and not publicly announced on
the date hereof or (3) compliance by the Liquidity Provider or any corporation
controlling the Liquidity Provider with any applicable guideline or request of
general applicability, issued after the date hereof and not publicly announced
on the date hereof, by any central bank or other governmental authority (whether
or not having the force of law but of the type with which the Liquidity Provider
is accustomed to comply) that constitutes a change of the nature described in
clause (2), has the effect of requiring an increase in the amount of capital
required to be maintained by the Liquidity Provider or any corporation
controlling the Liquidity Provider, and such increase is based upon the
Liquidity Provider's obligations hereunder and other similar obligations, the
Borrower shall pay to the Liquidity Provider from time to time such additional
amount or amounts as are necessary to compensate the Liquidity Provider for such
portion of such increase as shall be reasonably allocable to the Liquidity
Provider's obligations to the Borrower hereunder. The Liquidity Provider agrees
to use reasonable efforts (consistent with applicable legal and regulatory
restrictions) to change the jurisdiction of its Lending Office if making such
change would avoid the need for, or reduce the amount of, any amount payable
under this Section that may thereafter accrue and would not, in the reasonable
judgment of the Liquidity Provider, be otherwise materially disadvantageous to
the Liquidity Provider.

                  The Liquidity Provider will notify the Borrower of any event
occurring after the date of this Agreement that will entitle the Liquidity
Provider to compensation pursuant to this Section 3.02 as promptly as
practicable after it obtains knowledge thereof and determines to request such
compensation, which notice shall describe in reasonable detail the calculation
of the amounts owed under this Section; provided that if the Liquidity Provider
fails to give such notice within 30 days after it obtains such knowledge, the
Liquidity Provider shall, with respect of any costs resulting from such event,
only be entitled to payment under this Section 3.02 for costs incurred from and
after the date 30 days prior to the date the Liquidity Provider does give such
notice. Determinations by the Liquidity Provider for purposes of this Section
3.02 of the effect of any increase in the amount of capital required to be
maintained by the Liquidity Provider and of the amount allocable to the
Liquidity Provider's obligations to the Borrower hereunder shall be prima facie
evidence of the amounts owed under this Section.
<PAGE>   18
                                                                              14


                  The Liquidity Provider shall not be entitled to compensation
under this Section 3.02 if (1) it shall not be also seeking compensation (if it
should be so entitled) under other comparable contractual provisions in its
other agreements, (2) if its claim under this Section 3.02 arises through
circumstances peculiar to the Liquidity Provider and which do not affect a
similarly organized commercial banking institution in the same jurisdiction
generally, or (3) the Liquidity Provider is not the initial liquidity provider
and America West did not consent to the transfer of this facility to the
Liquidity Provider, for the amount, if any, payable under this Section 3.02
resulting from events occurring prior to the date the Liquidity Provider
acquired its interests hereunder as shall exceed the amount payable under this
Section 3.02 that would have been due to the Liquidity Provider's transferor had
it continued to be the liquidity provider hereunder.

                  Section 3.03. Payments Free of Deductions. (a) All payments
made by the Borrower under this Agreement shall be made free and clear of, and
without reduction for or on account of, any present or future stamp or other
taxes, levies, imposts, duties, deductions or withholdings, of a similar nature
other than Excluded Taxes (collectively, "Non-Excluded Taxes" and, individually,
a "Non-Excluded Tax"). If any Non-Excluded Taxes are required to be withheld
from any amounts payable to the Liquidity Provider under this Agreement, the
Liquidity Provider shall notify the Borrower and America West thereof and from
and after such notice, the amounts so payable to the Liquidity Provider shall be
increased to the extent necessary to yield to the Liquidity Provider (after
payment of all Non-Excluded Taxes) the amount it would have received had no such
deduction or withholding occurred. The Liquidity Provider agrees to use
reasonable efforts (consistent with its legal and regulatory restrictions) to
change the jurisdiction of its Lending Office if making such change would avoid
the need for, or reduce the amount of, any such additional amounts that may
thereafter accrue and shall otherwise take such reasonable steps as are open to
it to mitigate the effects of such circumstances provided that the Liquidity
Provider shall be under no obligation to take any such action if to do so would
have a material adverse effect on its business, operations or financial
condition or result in its rights, interests or position under this Agreement
being prejudiced or involved in any unlawful activity. From time to time upon
the reasonable request of the Borrower, the Liquidity Provider agrees to provide
to the Borrower two original Internal Revenue Service Form 1001 or 4224, as
appropriate, or any successor or other form prescribed by the Internal Revenue
Service, certifying that the Liquidity Provider is exempt from or entitled to a
reduced rate of United States withholding tax on payments pursuant to this
Agreement.

                  Section 3.04. Payments. The Borrower shall make or cause to be
made each payment to the Liquidity Provider under this Agreement so as to cause
the same to be received by the Liquidity Provider not later than 1:00 P.M. (New
York City time) on the day when due. The Borrower shall make all such payments
in lawful money of the United States of America, to the Liquidity Provider in
immediately available funds, by wire transfer to ABN AMRO Bank N.V., New York,
New York, ABA # 026009580 for account of ABN AMRO Bank N.V., Chicago Branch CPU,
Account No. 650-001-1789-41, Account Reference: America West Airlines Liquidity
Facility 1998-1C.

                  Section 3.05. Computations. All computations of interest based
on the Base Rate shall be made on the basis of a year of 365 or 366 days, as the
case may be, and all computations of interest based on the LIBOR Rate shall be
made on the basis of a year of 360 days, in each
<PAGE>   19
                                                                              15


case for the actual number of days (including the first day but excluding the
last day) occurring in the period for which such interest is payable.

                  Section 3.06. Payment on Non-Business Days. Whenever any
payment to be made hereunder shall be stated to be due on a day other than a
Business Day, such payment shall be made on the next succeeding Business Day and
no additional interest shall be due as a result (and if so made, shall be deemed
to have been made when due). If any payment in respect of interest on an Advance
is so deferred to the next succeeding Business Day, such deferral shall not
delay the commencement of the next Interest Period for such Advance (if such
Advance is a LIBOR Advance) or reduce the number of days for which interest will
be payable on such Advance on the next interest payment date for such Advance.

                  Section 3.07. Interest. (a) Subject to Section 2.09, the
Borrower shall pay, or shall cause to be paid, without duplication, interest on
(i) the unpaid principal amount of each Advance from and including the date of
such Advance (or, in the case of an Applied Provider Advance, from and including
the date on which the amount thereof was withdrawn from the Class C Cash
Collateral Account to pay interest on the Class C Certificates) to but excluding
the date such principal amount shall be paid in full (or, in the case of an
Applied Provider Advance, the date on which the Class C Cash Collateral Account
is fully replenished in respect of such Advance) and (ii) any other amount due
hereunder (whether fees, commissions, expenses or other amounts or, to the
extent permitted by law, installments of interest on Advances or any such other
amount) which is not paid when due (whether at stated maturity, by acceleration
or otherwise) from and including the due date thereof to but excluding the date
such amount is paid in full, in each such case, at a fluctuating interest rate
per annum for each day equal to the Applicable Liquidity Rate for such Advance
or such other amount as in effect for such day, but in no event at a rate per
annum greater than the maximum rate permitted by applicable law; provided,
however, that, if at any time the otherwise applicable interest rate as set
forth in this Section 3.07 shall exceed the maximum rate permitted by applicable
law, then any subsequent reduction in such interest rate will not reduce the
rate of interest payable pursuant to this Section 3.07 below the maximum rate
permitted by applicable law until the total amount of interest accrued equals
the amount of interest that would have accrued if such otherwise applicable
interest rate as set forth in this Section 3.07 had at all times been in effect.

                  (b) Each Advance will be either a Base Rate Advance or a LIBOR
Advance as provided in this Section. Each such Advance will be a Base Rate
Advance for the period from the date of its borrowing to (but excluding) the
third Business Day following the Liquidity Provider's receipt of the Notice of
Borrowing for such Advance. Thereafter, such Advance shall be a LIBOR Advance.

                  (c) Each LIBOR Advance shall bear interest during each
Interest Period at a rate per annum equal to the LIBOR Rate for such Interest
Period plus the Applicable Margin for such LIBOR Advance, payable in arrears on
the last day of such Interest Period and, in the event of the payment of
principal of such LIBOR Advance on a day other than such last day, on the date
of such payment (to the extent of interest accrued on the amount of principal
repaid).

                  (d) Each Base Rate Advance shall bear interest at a rate per
annum equal to the Base Rate plus the Applicable Margin for such Base Rate
Advance, payable in arrears on each Regular Distribution Date and, in the event
of the payment of principal of such Base Rate
<PAGE>   20
                                                                              16


Advance on a day other than a Regular Distribution Date, on the date of such
payment (to the extent of interest accrued on the amount of principal repaid).

                  (e) Each amount not paid when due hereunder (whether fees,
commissions, expenses or other amounts or, to the extent permitted by applicable
law, installments of interest on Advances but excluding Advances) shall bear
interest at a rate per annum equal to the Base Rate plus 2% until paid.

                  (f) Each change in the Base Rate shall become effective
immediately. The rates of interest specified in this Section 3.07 with respect
to any Advance or other amount shall be referred to as the "Applicable Liquidity
Rate".

                  Section 3.08. Replacement of Subordination Agent. From time to
time and subject to the successor Subordination Agent's meeting the eligibility
requirements set forth in Section 6.9 of the Intercreditor Agreement applicable
to the Subordination Agent, upon the effective date and time specified in a
written and completed Notice of Replacement Subordination Agent in substantially
the form of Annex VI attached hereto (a "Notice of Replacement Subordination
Agent") delivered to the Liquidity Provider by the then Subordination Agent, the
successor Subordination Agent designated therein shall be substituted for as the
Subordination Agent for all purposes hereunder.

                  Section 3.09. Funding Loss Indemnification. The Borrower shall
pay to the Liquidity Provider, upon the request of the Liquidity Provider, such
amount or amounts as shall be sufficient (in the reasonable opinion of the
Liquidity Provider) to compensate it for any loss incurred by it by reason of
the liquidation or redeployment of deposits or other funds acquired by the
Liquidity Provider to fund or maintain any LIBOR Advance (but excluding loss of
anticipated profits) incurred as a result of:

                  (1) Any repayment of a LIBOR Advance on a date other than the
         last day of the Interest Period for such Advance; or

                  (2) Any failure by the Borrower to borrow a LIBOR Advance on
         the date for borrowing specified in the relevant notice under Section
         2.02.

                  Section 3.10. Illegality. Notwithstanding any other provision
in this Agreement, if any change in any applicable law, rule or regulation not
publicly announced on the date hereof shall make it unlawful or impossible for
the Liquidity Provider (or its Lending Office) to maintain or fund its LIBOR
Advances without breaking such law, then upon notice to the Borrower by the
Liquidity Provider, the outstanding principal amount of the LIBOR Advances shall
be converted to Base Rate Advances to the extent necessary to cure such
illegality (a) immediately upon demand of the Liquidity Provider, if such change
or compliance with such request, in the judgment of the Liquidity Provider,
requires immediate repayment; or (b) at the expiration of the last Interest
Period to expire before the effective date of any such change or request. The
Liquidity Provider agrees to use reasonable efforts (consistent with applicable
legal and regulatory restrictions) to change the jurisdiction of its Lending
Office if making such change would avoid or cure the aforesaid illegality.
<PAGE>   21
                                                                              17


                                   ARTICLE IV

                              CONDITIONS PRECEDENT

                  Section 4.01. Conditions Precedent to Effectiveness of Section
2.01. Section 2.01 of this Agreement shall become effective on and as of the
first date (the "Effective Date") on which the following conditions precedent
have been satisfied or waived:

                  (a) The Liquidity Provider shall have received on or before
         the Closing Date each of the following, and in the case of each
         document delivered pursuant to paragraphs (i), (ii) and (iii), each in
         form and substance satisfactory to the Liquidity Provider:

                           (i) This Agreement duly executed on behalf of the
                  Borrower;

                           (ii) The Intercreditor Agreement duly executed on
                  behalf of each of the parties thereto;

                           (iii) Fully executed copies of each of the Operative
                  Agreements executed and delivered on or before the Closing
                  Date (other than this Agreement and the Intercreditor
                  Agreement);

                           (iv) A copy of the Offering Memorandum and specimen
                  copies of the Class C Certificates;

                           (v) An executed copy of each document, instrument,
                  certificate and opinion delivered on or before the Closing
                  Date pursuant to the Class C Trust Agreement, the
                  Intercreditor Agreement and the other Operative Agreements (in
                  the case of each such opinion, other than the opinion of
                  counsel for the Initial Purchasers, either addressed to the
                  Liquidity Provider or accompanied by a letter from the counsel
                  rendering such opinion to the effect that the Liquidity
                  Provider is entitled to rely on such opinion as of its date as
                  if it were addressed to the Liquidity Provider);

                           (vi) Evidence that there shall have been made and
                  shall be in full force and effect, all filings, recordings
                  and/or registrations, and there shall have been given or taken
                  any notice or other similar action as are necessary or in
                  order to establish, perfect, protect and preserve the right,
                  title and interest of the Liquidity Provider created by the
                  Operative Agreements executed and delivered on or prior to the
                  Closing Date;

                           (vii) An agreement from America West, pursuant to
                  which America West agrees to provide copies of quarterly
                  financial statements and audited annual financial statements
                  to the Liquidity Provider (which obligations may be satisfied
                  by the furnishing of America West's Form 10Q and 10K), in each
                  case, only to the extent that America West is obligated to
                  provide such information pursuant to Section 8.2.1 of the
                  Leases (related to Leased Aircraft) or the corresponding
                  section of the Indentures (related to Owned Aircraft) to the
                  parties thereto; and
<PAGE>   22
                                                                              18


                           (viii) Such other documents, instruments, opinions
                  and approvals pertaining to the transactions contemplated
                  hereby or by the other Operative Agreements as the Liquidity
                  Provider shall have reasonably requested.

                  (b) The following statement shall be true on and as of the
         Effective Date: no event has occurred and is continuing, or would
         result from the entering into of this Agreement or the making of any
         Advance, which constitutes a Liquidity Event of Default.

                  (c) The Liquidity Provider shall have received payment in full
         of all fees and other sums required to be paid to or for account of the
         Liquidity Provider on or prior to the Effective Date.

                  (d) All conditions precedent to the issuance of the
         Certificates under the Trust Agreements shall have been satisfied or
         waived, all conditions precedent to the effectiveness of the other
         Liquidity Facilities shall have been satisfied or waived, and all
         conditions precedent to the purchase of the Certificates by the Initial
         Purchasers under the Purchase Agreement shall have been satisfied
         (unless any of such conditions precedent shall have been waived by the
         Initial Purchasers).

                  (e) The Borrower shall have received a certificate, dated the
         date hereof, signed by a duly authorized representative of the
         Liquidity Provider, certifying that all conditions precedent to the
         effectiveness of Section 2.01 have been satisfied or waived.

                  Section 4.02. Conditions Precedent to Borrowing. The
obligation of the Liquidity Provider to make an Advance on the occasion of each
Borrowing shall be subject to the conditions precedent that the Effective Date
shall have occurred and, prior to the date of such Borrowing, the Borrower shall
have delivered a Notice of Borrowing which conforms to the terms and conditions
of this Agreement and has been completed as may be required by the relevant form
of the Notice of Borrowing for the type of Advances requested.

                                    ARTICLE V

                                    COVENANTS

                  Section 5.01. Affirmative Covenants of the Borrower. So long
as any Advance shall remain unpaid or the Liquidity Provider shall have any
Maximum Commitment hereunder or the Borrower shall have any obligation to pay
any amount to the Liquidity Provider hereunder, the Borrower will, unless the
Liquidity Provider shall otherwise consent in writing:

                  (a) Performance of This and Other Agreements. Punctually pay
         or cause to be paid all amounts payable by it under this Agreement and
         the other Operative Agreements and observe and perform in all material
         respects the conditions, covenants and requirements applicable to it
         contained in this Agreement and the other Operative Agreements.
<PAGE>   23
                                                                              19


                  (b) Reporting Requirements. Furnish to the Liquidity Provider
         with reasonable promptness, such other information and data with
         respect to the transactions contemplated by the Operative Agreements as
         from time to time may be reasonably requested by the Liquidity
         Provider; and permit the Liquidity Provider, upon reasonable notice, to
         inspect the Borrower's books and records with respect to such
         transactions and to meet with officers and employees of the Borrower to
         discuss such transactions.

                  (c) Certain Operative Agreements. Furnish to the Liquidity
         Provider with reasonable promptness, such Operative Agreements entered
         into after the date hereof as from time to time may be reasonably
         requested by the Liquidity Provider.

                  Section 5.02. Negative Covenants of the Borrower. So long as
any Advance shall remain unpaid or the Liquidity Provider shall have any Maximum
Commitment hereunder or the Borrower shall have any obligation to pay any amount
to the Liquidity Provider hereunder, the Borrower will not appoint or permit or
suffer to be appointed any successor Borrower without the prior written consent
of the Liquidity Provider, which consent shall not be unreasonably withheld or
delayed.

                                   ARTICLE VI

                           LIQUIDITY EVENTS OF DEFAULT

                  Section 6.01. Liquidity Events of Default. If (a) any
Liquidity Event of Default has occurred and is continuing and (b) there is a
Performing Note Deficiency, the Liquidity Provider may, in its discretion,
deliver to the Borrower a Termination Notice, the effect of which shall be to
cause (i) the obligation of the Liquidity Provider to make Advances hereunder to
expire on the fifth Business Day after the date on which such Termination Notice
is received by the Borrower, (ii) the Borrower to promptly request, and the
Liquidity Provider to promptly make, a Final Advance in accordance with Section
2.02(d) hereof and Section 3.6(i) of the Intercreditor Agreement, (iii) all
other outstanding Advances to be automatically converted into Final Advances for
purposes of determining the Applicable Liquidity Rate for interest payable
thereon, and (iv) subject to Sections 2.07 and 2.09 hereof, all Advances
(including, without limitation, any Provider Advance and Applied Provider
Advance), any accrued interest thereon and any other amounts outstanding
hereunder to become immediately due and payable to the Liquidity Provider.

                                   ARTICLE VII

                                  MISCELLANEOUS

                  Section 7.01. Amendments, Etc. No amendment or waiver of any
provision of this Agreement, nor consent to any departure by the Borrower
therefrom, shall in any event be effective unless the same shall be in writing
and signed by the Liquidity Provider, and, in the case of an amendment or of a
waiver by the Borrower, the Borrower, and then such waiver or consent shall be
effective only in the specific instance and for the specific purpose for which
given.
<PAGE>   24
                                                                              20


                  Section 7.02. Notices, Etc. Except as otherwise expressly
provided herein, all notices and other communications provided for hereunder
shall be in writing (including telecopier and mailed or delivered or sent by
telecopier):

                  Borrower:

                  Wilmington Trust Company
                  Rodney Square North
                  1100 North Market Square
                  Wilmington, DE  19890-0001

                  Attention: Corporate Trust Administration
                  Telephone: 302-651-1000
                  Telecopy: 302-651-8882

                  Liquidity Provider:

                  ABN AMRO BANK N.V.
                  135 South LaSalle Street - Suite 660
                  Chicago, Illinois 60603

                  Attention:  Vice President - Aerospace
                  Telephone:  (312) 904-2900
                  Telecopy:  (312) 606-8428

                  with a copy to:

                  ABN AMRO BANK N.V.
                  135 South LaSalle Street - Suite 625
                  Chicago, Illinois 60603

                  Attention:  Loan Administration
                  Telephone:  (312) 904-2961
                  Telecopy:  (312) 904-1288

or, as to each of the foregoing, at such other address as shall be designated by
such Person in a written notice to the others. All such notices and
communications shall be effective when received unless received outside of
business hours, in which case on the next open of business on a Business Day. A
copy of all notices delivered hereunder to either party shall in addition be
delivered to each of the parties to the Participation Agreements at their
respective addresses set forth therein.

                  Section 7.03. No Waiver; Remedies. No failure on the part of
the Liquidity Provider to exercise, and no delay in exercising, any right under
this Agreement shall operate as a waiver thereof; nor shall any single or
partial exercise of any right under this Agreement preclude any other or further
exercise thereof or the exercise of any other right. The remedies herein
provided are cumulative and not exclusive of any remedies provided by law.
<PAGE>   25
                                                                              21


                  Section 7.04. Further Assurances. The Borrower agrees to do
such further acts and things and to execute and deliver to the Liquidity
Provider such additional assignments, agreements, powers and instruments as the
Liquidity Provider may reasonably require or deem advisable to carry into effect
the purposes of this Agreement and the other Operative Agreements or to better
assure and confirm unto the Liquidity Provider its rights, powers and remedies
hereunder and under the other Operative Agreements.

                  Section 7.05. Indemnification; Survival of Certain Provisions.
The Liquidity Provider shall be indemnified hereunder to the extent and in the
manner described in Section 7.1 or 9.1, as the case may be, of the Participation
Agreements. The indemnities contained in Section 7.1 or 9.1, as the case may be,
of the Participation Agreements, and the provisions of Sections 3.01, 3.02,
3.03, 3.09, 7.05 and 7.07 hereof, shall survive the termination of this
Agreement.

                  Section 7.06. Liability of the Liquidity Provider. (a) Neither
the Liquidity Provider nor any of its officers, employees, directors or
affiliates shall be liable or responsible for: (i) the use which may be made of
the Advances or any acts or omissions of the Borrower or any beneficiary or
transferee in connection therewith; or (ii) the validity, sufficiency or
genuineness of documents, or of any endorsement thereon, even if such documents
should prove to be in any or all respects invalid, insufficient, fraudulent or
forged except as executed by the Liquidity Provider; provided, however, that the
Borrower shall have a claim against the Liquidity Provider, and the Liquidity
Provider shall be liable to the Borrower, to the extent of any damages suffered
by the Borrower which were the result of (A) the Liquidity Provider's willful
misconduct or negligence in determining whether documents presented hereunder
comply with the terms hereof, or (B) any breach by the Liquidity Provider of any
of the terms of this Agreement, including, but not limited to, the Liquidity
Provider's failure to make lawful payment hereunder after the delivery to it by
the Borrower of a Notice of Borrowing strictly complying with the terms and
conditions hereof.

                  (b) Neither the Liquidity Provider nor any of its officers,
employees, directors or affiliates shall be liable or responsible in any respect
for (i) any error, omission, interruption or delay in transmission, dispatch or
delivery of any message or advice, however transmitted, in connection with this
Agreement or any Notice of Borrowing delivered hereunder, or (ii) any action,
inaction or omission which may be taken by it in good faith, absent willful
misconduct or negligence (in which event the extent of the Liquidity Provider's
potential liability to the Borrower shall be limited as set forth in the
immediately preceding paragraph), in connection with this Agreement or any
Notice of Borrowing.

                  Section 7.07. Costs, Expenses and Taxes. The Borrower agrees
to pay, or cause to be paid (A) on the Effective Date and on such later date or
dates on which the Liquidity Provider shall make demand, all reasonable
out-of-pocket costs and expenses (including, without limitation, the reasonable
fees and expenses of outside counsel for the Liquidity Provider) of the
Liquidity Provider in connection with the preparation, negotiation, execution,
delivery, filing and recording of this Agreement, any other Operative Agreement
and any other documents which may be delivered in connection with this Agreement
and (B) on demand, all reasonable costs and expenses (including reasonable
counsel fees and expenses) of the Liquidity Provider in connection with (i) the
enforcement of this Agreement or any other Operative Agreement, (ii) the
modification or amendment of, or supplement to, this Agreement or any other
Operative
<PAGE>   26
                                                                              22


Agreement or such other documents which may be delivered in connection herewith
or therewith (whether or not the same shall become effective) other than
amendments requested by the Liquidity Provider or a transfer made by the
Liquidity Provider either voluntarily or as a result of the mitigation
provisions of Article 3 or a Non-Extension Drawing or a Downgrade Drawing or
(iii) any action or proceeding relating to any order, injunction, or other
process or decree restraining or seeking to restrain the Liquidity Provider from
paying any amount under this Agreement, the Intercreditor Agreement or any other
Operative Agreement or otherwise affecting the application of funds in the Class
C Cash Collateral Accounts. In addition, the Borrower shall pay any and all
recording, stamp and other similar taxes and fees payable or determined to be
payable in connection with the execution, delivery, filing and recording of this
Agreement, any other Operative Agreement and such other documents, other than
amendments requested by the Liquidity Provider or a transfer made by the
Liquidity Provider either voluntarily or as a result of the mitigation
provisions of Article 3 or a Non-Extension Drawing or a Downgrade Drawing, and
agrees to save the Liquidity Provider harmless from and against any and all
liabilities with respect to or resulting from any delay in paying or omission to
pay such taxes or fees.

                  Section 7.08. Binding Effect; Participations. (a) This
Agreement shall be binding upon and inure to the benefit of the Borrower and the
Liquidity Provider and their respective successors and assigns, except that
neither the Liquidity Provider (except as otherwise provided in this Section
7.08) nor (except as contemplated by Section 3.08) the Borrower shall have the
right to assign its rights or obligations hereunder or any interest herein
without the prior written consent of the other party, subject to the
requirements of Section 7.08(b). The Liquidity Provider may grant participations
herein or in any of its rights hereunder (including, without limitation, funded
participations and participations in rights to receive interest payments
hereunder) and under the other Operative Agreements to such Persons as the
Liquidity Provider may in its sole discretion select, subject to the
requirements of Section 7.08(b). No such participation by the Liquidity
Provider, however, will relieve the Liquidity Provider of its obligations
hereunder. In connection with any participation or any proposed participation,
the Liquidity Provider may disclose to the participant or the proposed
participant any information that the Borrower is required to deliver or to
disclose to the Liquidity Provider pursuant to this Agreement. The Borrower
acknowledges and agrees that the Liquidity Provider's source of funds may derive
in part from its participants (other than America West). Accordingly, references
in this Agreement and the other Operative Agreements to determinations, reserve
and capital adequacy requirements, increased costs, reduced receipts, additional
amounts due pursuant to Section 3.03 and the like as they pertain to the
Liquidity Provider shall be deemed also to include those of each of its
participants (subject, in each case, to the maximum amount that would have been
incurred by or attributable to the Liquidity Provider directly if the Liquidity
Provider, rather than the participant, had held the interest participated).

                  (b) If, pursuant to subsection (a) above, the Liquidity
Provider sells any participation in this Agreement to any bank or other entity
(each, a "Transferee"), then, concurrently with the effectiveness of such
participation, the Transferee shall (i) represent to the Liquidity Provider (for
the benefit of the Liquidity Provider and the Borrower) either (A) that it is
incorporated under the laws of the United States or a state thereof or (B) that
under applicable law and treaties, no taxes will be required to be withheld with
respect to any payments to be made to such Transferee in respect of this
Agreement, (ii) furnish to the Liquidity Provider and the Borrower either (x) a
statement that it is incorporated under the laws of the United States or a
<PAGE>   27
                                                                              23


state thereof or (y) if it is not so incorporated, two copies of a properly
completed United States Internal Revenue Service Form 4224 or Form 1001, as
appropriate, or other applicable form, certificate or document prescribed by the
Internal Revenue Service certifying, in each case, such Transferee's entitlement
to a complete exemption from United States federal withholding tax in respect to
any and all payments to be made hereunder, and (iii) agree (for the benefit of
the Liquidity Provider and the Borrower) to provide the Liquidity Provider and
the Borrower a new Form 4224 or Form 1001, as appropriate, (A) on or before the
date that any such form expires or becomes obsolete or (B) after the occurrence
of any event requiring a change in the most recent form previously delivered by
it and prior to the immediately following due date of any payment by the
Borrower hereunder, certifying in the case of a Form 1001 or Form 4224 that such
Transferee is entitled to a complete exemption from United States federal
withholding tax on payments under this Agreement. Unless the Borrower has
received forms or other documents reasonably satisfactory to it (and required by
applicable law) indicating that payments hereunder are not subject to United
States federal withholding tax, the Borrower will withhold taxes as required by
law from such payments at the applicable statutory rate.

                  (c) Notwithstanding the other provisions of this Section 7.08,
the Liquidity Provider may assign and pledge all or any portion of the Advances
owing to it to any Federal Reserve Bank or the United States Treasury as
collateral security pursuant to Regulation A of the Board of Governors of the
Federal Reserve System and any Operating Circular issued by such Federal Reserve
Bank, provided that any payment in respect of such assigned Advances made by the
Borrower to the Liquidity Provider in accordance with the terms of this
Agreement shall satisfy the Borrower's obligations hereunder in respect of such
assigned Advance to the extent of such payment. No such assignment shall release
the Liquidity Provider from its obligations hereunder.

                  Section 7.09. Severability. Any provision of this Agreement
which is prohibited, unenforceable or not authorized in any jurisdiction shall,
as to such jurisdiction, be ineffective to the extent of such prohibition,
unenforceability or non-authorization without invalidating the remaining
provisions hereof or affecting the validity, enforceability or legality of such
provision in any other jurisdiction.

                  Section 7.10. GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED
BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.

                  Section 7.11. Submission to Jurisdiction; Waiver of Jury
Trial; Waiver of Immunity. (a) Each of the parties hereto hereby irrevocably and
unconditionally:

                  (i) submits for itself and its property in any legal action or
         proceeding relating to this Agreement or any other Operative Agreement,
         or for recognition and enforcement of any judgment in respect hereof or
         thereof, to the nonexclusive general jurisdiction of the courts of the
         State of New York, the courts of the United States of America for the
         Southern District of New York, and the appellate courts from any
         thereof;

                  (ii) consents that any such action or proceeding may be
         brought in such courts, and waives any objection that it may now or
         hereafter have to the venue of any
<PAGE>   28
                                                                              24


         such action or proceeding in any such court or that such action or
         proceeding was brought in an inconvenient court and agrees not to plead
         or claim the same;

                  (iii) agrees that service of process in any such action or
         proceeding may be effected by mailing a copy thereof by registered or
         certified mail (or any substantially similar form and mail), postage
         prepaid, to each party hereto at its address set forth in Section 7.02
         hereof, or at such other address of which the Liquidity Provider shall
         have been notified pursuant thereto; and

                  (iv) agrees that nothing herein shall affect the right to
         effect service of process in any other manner permitted by law or shall
         limit the right to sue in any other jurisdiction.

                  (b) THE BORROWER AND THE LIQUIDITY PROVIDER EACH HEREBY AGREE
TO WAIVE THEIR RESPECTIVE RIGHTS TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION
BASED UPON OR ARISING OUT OF THIS AGREEMENT OR ANY DEALINGS BETWEEN THEM
RELATING TO THE SUBJECT MATTER OF THIS AGREEMENT AND THE RELATIONSHIP THAT IS
BEING ESTABLISHED, including, without limitation, contract claims, tort claims,
breach of duty claims and all other common law and statutory claims. The
Borrower and the Liquidity Provider each warrant and represent that it has
reviewed this waiver with its legal counsel, and that it knowingly and
voluntarily waives its jury trial rights following consultation with such legal
counsel. THIS WAIVER IS IRREVOCABLE, AND CANNOT BE MODIFIED EITHER ORALLY OR IN
WRITING, AND THIS WAIVER SHALL APPLY TO ANY SUBSEQUENT AMENDMENTS, RENEWALS,
SUPPLEMENTS OR MODIFICATIONS TO THIS AGREEMENT.

                  (c) The Liquidity Provider hereby waives any immunity it may
have from the jurisdiction of the courts of the United States or of any State
and waives any immunity any of its properties located in the United States may
have from attachment or execution upon a judgment entered by any such court
under the United States Foreign Sovereign Immunities Act of 1976 or any similar
successor legislation.

                  Section 7.12. Execution in Counterparts. This Agreement may be
executed in any number of counterparts and by different parties hereto on
separate counterparts, each of which counterparts, when so executed and
delivered, shall be deemed to be an original and all of which counterparts,
taken together, shall constitute but one and the same Agreement.

                  Section 7.13. Entirety. This Agreement, the Intercreditor
Agreement and the other Operative Agreements to which the Liquidity Provider is
a party constitute the entire agreement of the parties hereto with respect to
the subject matter hereof and supersedes all prior understandings and agreements
of such parties.

                  Section 7.14. Headings. Section headings in this Agreement are
included herein for convenience of reference only and shall not constitute a
part of this Agreement for any other purpose.
<PAGE>   29
                                                                              25


                  Section 7.15. Transfer. The Liquidity Provider hereby
acknowledges and consents to the Transfer contemplated by the Assignment and
Assumption Agreement.

                  Section 7.16. LIQUIDITY PROVIDER'S OBLIGATION TO MAKE
ADVANCES. EXCEPT AS EXPRESSLY SET FORTH IN THIS AGREEMENT, THE OBLIGATIONS OF
THE LIQUIDITY PROVIDER TO MAKE ADVANCES HEREUNDER, AND THE BORROWER'S RIGHTS TO
DELIVER NOTICES OF BORROWING REQUESTING THE MAKING OF ADVANCES HEREUNDER, SHALL
BE UNCONDITIONAL AND IRREVOCABLE, AND SHALL BE PAID OR PERFORMED, IN EACH CASE
STRICTLY IN ACCORDANCE WITH THE TERMS OF THIS AGREEMENT.
<PAGE>   30
                                                                              

                  IN WITNESS WHEREOF, the parties have caused this Agreement to
be duly executed and delivered by their respective officers thereunto duly
authorized as of the date first set forth above.

                            WILMINGTON TRUST COMPANY,

                                    not in its individual capacity but solely as
                                    Subordination Agent, as agent and trustee
                                    for the Class C Trust, as Borrower

                             By:  /s/ Jill K. Morrison
                                ------------------------------------
                                Name:  Jill K. Morrison
                                Title: Administrative Account Manager


                             ABN AMRO BANK N.V., Chicago Branch
                             as Liquidity Provider



                             By:  /s/ Claudia C. Heldring
                                ------------------------------------
                                Name:  Claudia C. Heldring
                                Title: Vice President



                             By:  /s/ Carla S. Waggoner
                                ------------------------------------
                                Name:  Carla S. Waggoner
                                Title: Assistant Vice President
<PAGE>   31
                                                                      Annex I to
                                                      Revolving Credit Agreement

                      INTEREST ADVANCE NOTICE OF BORROWING

                  The undersigned, a duly authorized signatory of the
undersigned borrower (the "Borrower"), hereby certifies to ABN AMRO BANK, N.V.,
Chicago Branch (the "Liquidity Provider"), with reference to the Revolving
Credit Agreement (1998-1C) dated as of October 6, 1998, between the Borrower and
the Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and
not otherwise defined herein being used herein as therein defined or
referenced), that:

                  (1) The Borrower is the Subordination Agent under the
         Intercreditor Agreement.

                  (2) The Borrower is delivering this Notice of Borrowing for
         the making of an Interest Advance by the Liquidity Provider to be used,
         subject to clause (3)(v) below, for the payment of interest on the
         Class C Certificates which was payable on ____________, ____ (the
         "Distribution Date") in accordance with the terms and provisions of the
         Class C Trust Agreement and the Class C Certificates, which Advance is
         requested to be made on the date hereof.

                  (3) The amount of the Interest Advance requested hereby (i) is
         $_______________.__, to be applied in respect of the payment of the
         interest which was due and payable on the Class C Certificates on the
         Distribution Date, (ii) does not include any amount with respect to the
         payment of principal of, or premium on, the Class A Certificates, the
         Class B Certificates or the Class C Certificates, or interest on the
         Class A Certificates or the Class B Certificates, (iii) was computed in
         accordance with the provisions of the Class C Certificates, the Class C
         Trust Agreement and the Intercreditor Agreement (a copy of which
         computation is attached hereto as Schedule I), (iv) does not exceed the
         Maximum Available Commitment on the date hereof, (v) does not include
         any amount of interest which was due and payable on the Class C
         Certificates on such Distribution Date but which remains unpaid due to
         the failure of the Depositary to pay any amount of accrued interest on
         the Deposits on such Distribution Date and (vi) has not been and is not
         the subject of a prior or contemporaneous Notice of Borrowing.

                  (4) Upon receipt by or on behalf of the Borrower of the amount
         requested hereby, (a) the Borrower will apply the same in accordance
         with the terms of Section 3.6(b) of the Intercreditor Agreement, (b) no
         portion of such amount shall be applied by the Borrower for any other
         purpose and (c) no portion of such amount until so applied shall be
         commingled with other funds held by the Borrower.

                  The Borrower hereby acknowledges that, pursuant to the
Liquidity Agreement, the making of the Interest Advance as requested by this
Notice of Borrowing shall automatically reduce, subject to reinstatement in
accordance with the terms of the Liquidity Agreement, the Maximum Available
Commitment by an amount equal to the amount of the Interest Advance

                                      I-1
<PAGE>   32
requested to be made hereby as set forth in clause (i) of paragraph (3) of this
Certificate and such reduction shall automatically result in corresponding
reductions in the amounts available to be borrowed pursuant to a subsequent
Advance.

                  IN WITNESS WHEREOF, the Borrower has executed and delivered
this Notice of Borrowing as of the ____ day of _________, ____.


                                            WILMINGTON TRUST COMPANY,
                                                     not in its individual
                                                     capacity but solely as
                                                     Subordination Agent, as
                                                     Borrower

                                            By:_________________________________
                                                 Name:
                                                 Title:


                                      I-2
<PAGE>   33
               SCHEDULE I TO INTEREST ADVANCE NOTICE OF BORROWING

   [Insert Copy of Computations in accordance with Interest Advance Notice of
                                   Borrowing]


                                      I-2
<PAGE>   34
                                                                     Annex II to
                                                      Revolving Credit Agreement

                    NON-EXTENSION ADVANCE NOTICE OF BORROWING

                  The undersigned, a duly authorized signatory of the
undersigned subordination agent (the "Borrower"), hereby certifies to ABN AMRO
BANK N.V., Chicago Branch (the "Liquidity Provider"), with reference to the
Revolving Credit Agreement (1998-1C) dated as of October 6, 1998, between the
Borrower and the Liquidity Provider (the "Liquidity Agreement"; the terms
defined therein and not otherwise defined herein being used herein as therein
defined or referenced), that:

                  (1) The Borrower is the Subordination Agent under the
         Intercreditor Agreement.

                  (2) The Borrower is delivering this Notice of Borrowing for
         the making of the Non-Extension Advance by the Liquidity Provider to be
         used for the funding of the Class C Cash Collateral Account in
         accordance with Section 3.6(d) of the Intercreditor Agreement, which
         Advance is requested to be made on __________, ____.

                  (3) The amount of the Non-Extension Advance requested hereby
         (i) is $______________, which equals the Maximum Available Commitment
         on the date hereof and is to be applied in respect of the funding of
         the Class C Cash Collateral Account in accordance with Section 3.6(d)
         of the Intercreditor Agreement, (ii) does not include any amount with
         respect to the payment of the principal of, or premium on, the Class C
         Certificates, or principal of, or interest or premium on, the Class A
         Certificates or the Class B Certificates, (iii) was computed in
         accordance with the provisions of the Class C Certificates, the Class C
         Trust Agreement and the Intercreditor Agreement (a copy of which
         computation is attached hereto as Schedule I), and (iv) has not been
         and is not the subject of a prior or contemporaneous Notice of
         Borrowing under the Liquidity Agreement.

                  (4) Upon receipt by or on behalf of the Borrower of the amount
         requested hereby, (a) the Borrower will deposit such amount in the
         Class C Cash Collateral Account and apply the same in accordance with
         the terms of Section 3.6(d) of the Intercreditor Agreement, (b) no
         portion of such amount shall be applied by the Borrower for any other
         purpose and (c) no portion of such amount until so applied shall be
         commingled with other funds held by the Borrower.

                  The Borrower hereby acknowledges that, pursuant to the
Liquidity Agreement, (A) the making of the Non-Extension Advance as requested by
this Notice of Borrowing shall automatically and irrevocably terminate the
obligation of the Liquidity Provider to make further Advances under the
Liquidity Agreement; and (B) following the making by the Liquidity Provider of
the Non-Extension Advance requested by this Notice of Borrowing, the Borrower
shall not be entitled to request any further Advances under the Liquidity
Agreement.

                                      II-1

<PAGE>   35
                  IN WITNESS WHEREOF, the Borrower has executed and delivered
this Notice of Borrowing as of the ____ day of _________, ____.

                                   WILMINGTON TRUST COMPANY,
                                       not in its individual capacity but solely
                                       as Subordination Agent, as Borrower

                                   By:_________________________________
                                      Name:
                                      Title:


                                      II-2
<PAGE>   36
             SCHEDULE I TO NON-EXTENSION ADVANCE NOTICE OF BORROWING

[Insert Copy of computations in accordance with Non-Extension Advance Notice of
                                   Borrowing]


                                      II-2
<PAGE>   37
                                                                    Annex III to
                                                      Revolving Credit Agreement

                      DOWNGRADE ADVANCE NOTICE OF BORROWING

                  The undersigned, a duly authorized signatory of the
undersigned subordination agent (the "Borrower"), hereby certifies to ABN AMRO
BANK N.V., Chicago Branch (the "Liquidity Provider"), with reference to the
Revolving Credit Agreement (1998-1C) dated as of October 6, 1998, between the
Borrower and the Liquidity Provider (the "Liquidity Agreement"; the terms
defined therein and not otherwise defined herein being used herein as therein
defined or referenced), that:

                  (1) The Borrower is the Subordination Agent under the
         Intercreditor Agreement.

                  (2) The Borrower is delivering this Notice of Borrowing for
         the making of the Downgrade Advance by the Liquidity Provider to be
         used for the funding of the Class C Cash Collateral Account in
         accordance with Section 3.6(c) of the Intercreditor Agreement by reason
         of the downgrading of the short-term unsecured debt rating of the
         Liquidity Provider issued by either Rating Agency below the Threshold
         Rating, which Advance is requested to be made on __________, ____.

                  (3) The amount of the Downgrade Advance requested hereby (i)
         is $________________, which equals the Maximum Available Commitment on
         the date hereof and is to be applied in respect of the funding of the
         Class C Cash Collateral Account in accordance with Section 3.6(c) of
         the Intercreditor Agreement, (ii) does not include any amount with
         respect to the payment of the principal of, or premium on, the Class C
         Certificates, or principal of, or interest or premium on, the Class A
         Certificates or the Class B Certificates, (iii) was computed in
         accordance with the provisions of the Class C Certificates, the Class C
         Trust Agreement and the Intercreditor Agreement (a copy of which
         computation is attached hereto as Schedule I), and (iv) has not been
         and is not the subject of a prior or contemporaneous Notice of
         Borrowing under the Liquidity Agreement.

                  (4) Upon receipt by or on behalf of the Borrower of the amount
         requested hereby, (a) the Borrower will deposit such amount in the
         Class C Cash Collateral Account and apply the same in accordance with
         the terms of Section 3.6(c) of the Intercreditor Agreement, (b) no
         portion of such amount shall be applied by the Borrower for any other
         purpose and (c) no portion of such amount until so applied shall be
         commingled with other funds held by the Borrower.

                  The Borrower hereby acknowledges that, pursuant to the
Liquidity Agreement, (A) the making of the Downgrade Advance as requested by
this Notice of Borrowing shall automatically and irrevocably terminate the
obligation of the Liquidity Provider to make further Advances under the
Liquidity Agreement; and (B) following the making by the Liquidity
<PAGE>   38
Provider of the Downgrade Advance requested by this Notice of Borrowing, the
Borrower shall not be entitled to request any further Advances under the
Liquidity Agreement.

                  IN WITNESS WHEREOF, the Borrower has executed and delivered
this Notice of Borrowing as of the ____ day of _________, ____.

                             WILMINGTON TRUST COMPANY,
                                      not in its individual capacity but solely
                                      as Subordination Agent, as Borrower

                             By:_________________________________
                                  Name:
                                  Title:
<PAGE>   39
               SCHEDULE I TO DOWNGRADE ADVANCE NOTICE OF BORROWING

  [Insert Copy of computations in accordance with Downgrade Advance Notice of
                                   Borrowing]
<PAGE>   40
                                                                     Annex IV to
                                                      Revolving Credit Agreement

                        FINAL ADVANCE NOTICE OF BORROWING

                  The undersigned, a duly authorized signatory of the
undersigned borrower (the "Borrower"), hereby certifies to ABN AMRO BANK N.V.,
Chicago Branch (the "Liquidity Provider"), with reference to the Revolving
Credit Agreement (1998-1C) dated as of October 6, 1998, between the Borrower and
the Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and
not otherwise defined herein being used herein as therein defined or
referenced), that:

                  (1) The Borrower is the Subordination Agent under the
         Intercreditor Agreement.

                  (2) The Borrower is delivering this Notice of Borrowing for
         the making of the Final Advance by the Liquidity Provider to be used
         for the funding of the Class C Cash Collateral Account in accordance
         with Section 3.6(i) of the Intercreditor Agreement by reason of the
         receipt by the Borrower of a Termination Notice from the Liquidity
         Provider with respect to the Liquidity Agreement, which Advance is
         requested to be made on ____________, ____.

                  (3) The amount of the Final Advance requested hereby (i) is
         $_________________, which equals the Maximum Available Commitment on
         the date hereof and is to be applied in respect of the funding of the
         Class C Cash Collateral Account in accordance with Section 3.6(i) of
         the Intercreditor Agreement, (ii) does not include any amount with
         respect to the payment of principal of, or premium on, the Class C
         Certificates, or principal of, or interest or premium on, the Class A
         Certificates or the Class B Certificates, (iii) was computed in
         accordance with the provisions of the Class C Certificates, the Class C
         Trust Agreement and the Intercreditor Agreement (a copy of which
         computation is attached hereto as Schedule I), and (iv) has not been
         and is not the subject of a prior or contemporaneous Notice of
         Borrowing.

                  (4) Upon receipt by or on behalf of the Borrower of the amount
         requested hereby, (a) the Borrower will deposit such amount in the
         Class C Cash Collateral Account and apply the same in accordance with
         the terms of Section 3.6(i) of the Intercreditor Agreement, (b) no
         portion of such amount shall be applied by the Borrower for any other
         purpose and (c) no portion of such amount until so applied shall be
         commingled with other funds held by the Borrower.

                  The Borrower hereby acknowledges that, pursuant to the
Liquidity Agreement, (A) the making of the Final Advance as requested by this
Notice of Borrowing shall automatically and irrevocably terminate the obligation
of the Liquidity Provider to make further Advances under the Liquidity
Agreement; and (B) following the making by the Liquidity Provider of the Final
Advance requested by this Notice of Borrowing, the Borrower shall not be
entitled to request any further Advances under the Liquidity Agreement.


                                      IV-1
<PAGE>   41
                  IN WITNESS WHEREOF, the Borrower has executed and delivered
this Notice of Borrowing as of the ____ day of _________, ____.

                             WILMINGTON TRUST COMPANY,
                                      not in its individual capacity but solely
                                      as Subordination Agent, as Borrower

                             By:_________________________________
                                  Name:
                                  Title:
<PAGE>   42
                 SCHEDULE I TO FINAL ADVANCE NOTICE OF BORROWING

    [Insert Copy of Computations in accordance with Final Advance Notice of
                                   Borrowing]
<PAGE>   43
                                                                      Annex V to
                                                      Revolving Credit Agreement

                              NOTICE OF TERMINATION

                                     [Date]

Wilmington Trust Company,
  as Subordination Agent, as Borrower
Rodney Square North
1100 North Market Square
Wilmington, DE  19890-0001

Re:      Revolving Credit Agreement dated as of October 6, 1998, between
         Wilmington Trust Company, as Subordination Agent, as agent and trustee
         for the America West Airlines Pass Through Trust, 1998-1C-[O/S], as
         Borrower, and ABN AMRO Bank N.V., Chicago Branch, as the Liquidity
         Provider (the "Liquidity Agreement")

Ladies and Gentlemen:

                  You are hereby notified that pursuant to Section 6.01 of the
Liquidity Agreement, by reason of the occurrence of a Liquidity Event of Default
and the existence of a Performing Note Deficiency (each as defined therein), we
are giving this notice to you in order to cause (i) our obligations to make
Advances (as defined therein) under such Liquidity Agreement to terminate on the
fifth Business Day after the date on which you receive this notice and (ii) you
to request a Final Advance under the Liquidity Agreement pursuant to Section
3.6(i) of the Intercreditor Agreement (as defined in the Liquidity Agreement) as
a consequence of your receipt of this notice.


                                      V-1
<PAGE>   44
                  THIS NOTICE IS THE "NOTICE OF TERMINATION" PROVIDED FOR UNDER
THE LIQUIDITY AGREEMENT. OUR OBLIGATIONS TO MAKE ADVANCES UNDER THE LIQUIDITY
AGREEMENT WILL TERMINATE ON THE FIFTH BUSINESS DAY AFTER THE DATE ON WHICH YOU
RECEIVE THIS NOTICE.

                                           Very truly yours,

                                           ABN AMRO BANK N.V., Chicago Branch
                                               as Liquidity Provider

                                           By:_________________________________
                                                Name:
                                                Title:

                                           By:_________________________________
                                                Name:
                                                Title:
cc:      WILMINGTON TRUST COMPANY,
           as Class C Trustee


                                      V-2
<PAGE>   45
                                                                     Annex VI to
                                                      Revolving Credit Agreement

                    NOTICE OF REPLACEMENT SUBORDINATION AGENT

[Date]
Attention:

         Revolving Credit Agreement dated as of October 6, 1998, between
         WILMINGTON TRUST COMPANY, as Subordination Agent, as agent and trustee
         for the America West Airlines Pass Through Trust, 1998-1C-[O/S], as
         Borrower, and ABN AMRO Bank N.V., Chicago Branch, as the Liquidity
         Provider (the "Liquidity Agreement")

Ladies and Gentlemen:

                  For value received, the undersigned beneficiary hereby
irrevocably transfers to:

                         ------------------------------
                              [Name of Transferee]

                         ------------------------------
                             [Address of Transferee]

all rights and obligations of the undersigned as Borrower under the Liquidity
Agreement referred to above. The transferee has succeeded the undersigned as
Subordination Agent under the Intercreditor Agreement referred to in the first
paragraph of the Liquidity Agreement, pursuant to the terms of Section 8.1 of
the Intercreditor Agreement.

                  By this transfer, all rights of the undersigned as Borrower
under the Liquidity Agreement are transferred to the transferee and the
transferee shall hereafter have the sole rights and obligations as Borrower
thereunder. The undersigned shall pay any costs and expenses of such transfer,
including, but not limited to, transfer taxes or governmental charges.


                                      VI-1
<PAGE>   46
         We ask that this transfer be effective as of _______________, ____.

                              WILMINGTON TRUST COMPANY,
                                       not in its individual capacity but solely
                                       as Subordination Agent, as Borrower

                              By:_________________________________
                                   Name:
                                   Title:


                                      VI-2

<PAGE>   1
                                                                    Exhibit 4.13


                                                                       EXECUTION
- --------------------------------------------------------------------------------


                             INTERCREDITOR AGREEMENT

                                   Dated as of

                                 October 6, 1998

                                      among

                            WILMINGTON TRUST COMPANY,
                         not in its individual capacity
                         but solely as Trustee under the
                America West Airlines Pass Through Trust 1998-1A,
                America West Airlines Pass Through Trust 1998-1B
                                       and
                America West Airlines Pass Through Trust 1998-1C

                               ABN AMRO BANK N.V.,
                                 Chicago Branch
                         as Class A Liquidity Provider,
                          as Class B Liquidity Provider
                                       and
                         as Class C Liquidity Provider,

                                       and

                            WILMINGTON TRUST COMPANY,
                      not in its individual capacity except
                        as expressly set forth herein but
                    solely as Subordination Agent and Trustee


- --------------------------------------------------------------------------------
<PAGE>   2
                               TABLE OF CONTENTS

<TABLE>
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                              ARTICLE I DEFINITIONS

SECTION 1.1.     Definitions.............................................       2

               ARTICLE II TRUST ACCOUNTS; CONTROLLING PARTY

SECTION 2.1.     Agreement to Terms of Subordination; Payments from Monies
                 Received Only...........................................      20
SECTION 2.2.     Trust Accounts..........................................      21
SECTION 2.3.     Deposits to the Collection Account and Special Payments
                 Account.................................................      22
SECTION 2.4.     Distributions of Special Payments.......................      22
SECTION 2.5.     Designated Representatives..............................      25
SECTION 2.6.     Controlling Party.......................................      25


 ARTICLE III RECEIPT, DISTRIBUTION AND APPLICATION OF AMOUNTS RECEIVED

SECTION 3.1.     Written Notice of Distribution..........................      27
SECTION 3.2.     Distribution of Amounts on Deposit in the Collection
                 Account.................................................      29
SECTION 3.3.     Distribution of Amounts on Deposit Following a Triggering
                 Event...................................................      30
SECTION 3.4.     Other Payments..........................................      32
SECTION 3.5.     Payments to the Trustees and the Liquidity Providers....      32
SECTION 3.6.     Liquidity Facilities....................................      32


                      ARTICLE IV EXERCISE OF REMEDIES

SECTION 4.1.     Directions from the Controlling Party...................      38
SECTION 4.2.     Remedies Cumulative.....................................      40
SECTION 4.3.     Discontinuance of Proceedings...........................      40
SECTION 4.4.     Right of Certificateholders to Receive Payments Not to Be
                 Impaired................................................      40
SECTION 4.5.     Undertaking for Costs...................................      40

       ARTICLE V DUTIES OF THE SUBORDINATION AGENT; AGREEMENTS OF
                             TRUSTEES, ETC.

SECTION 5.1.     Notice of Indenture Default or Triggering Event.........      41
SECTION 5.2.     Indemnification.........................................      41
SECTION 5.3.     No Duties Except as Specified in Intercreditor Agreement      41
SECTION 5.4.     Notice from the Liquidity Providers and Trustees........      41


                    ARTICLE VI THE SUBORDINATION AGENT

SECTION 6.1.     Authorization; Acceptance of Trusts and Duties..........      42
</TABLE>


                                       i
<PAGE>   3
<TABLE>
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SECTION 6.2.     Absence of Duties.......................................      42
SECTION 6.3.     No Representations or Warranties as to Documents........      42
SECTION 6.4.     No Segregation of Monies; No Interest...................      42
SECTION 6.5.     Reliance; Agents; Advice of Counsel.....................      43
SECTION 6.6.     Capacity in Which Acting................................      43
SECTION 6.7.     Compensation............................................      43
SECTION 6.8.     May Become Certificateholder............................      43
SECTION 6.9.     Subordination Agent Required; Eligibility...............      43
SECTION 6.10.    Money to Be Held in Trust...............................      44


           ARTICLE VII INDEMNIFICATION OF SUBORDINATION AGENT

SECTION 7.1.     Scope of Indemnification................................      44


               ARTICLE VIII SUCCESSOR SUBORDINATION AGENT

SECTION 8.1.     Replacement of Subordination Agent; Appointment of
                 Successor...............................................      44


                   ARTICLE IX SUPPLEMENTS AND AMENDMENTS

SECTION 9.1.     Amendments, Waivers, etc. ..............................      45
SECTION 9.2.     Subordination Agent Protected...........................      47
SECTION 9.3.     Effect of Supplemental Agreements.......................      47
SECTION 9.4.     Notice to Rating Agencies...............................      47


                          ARTICLE X MISCELLANEOUS

SECTION 10.1.    Termination of Intercreditor Agreement..................      48
SECTION 10.2.    Intercreditor Agreement for Benefit of Trustees,
                 Liquidity Providers and Subordination Agent.............      48
SECTION 10.3.    Notices.................................................      48
SECTION 10.4.    Severability............................................      49
SECTION 10.5.    No Oral Modifications or Continuing Waivers.............      49
SECTION 10.6.    Successors and Assigns..................................      49
SECTION 10.7.    Headings................................................      50
SECTION 10.8.    Counterpart Form........................................      50
SECTION 10.9.    Subordination...........................................      50
SECTION 10.10.   Governing Law...........................................      51
SECTION 10.11.   Submission to Jurisdiction; Waiver of Jury Trial; Waiver
                 of Immunity.............................................      51
</TABLE>


                                       ii
<PAGE>   4
                             INTERCREDITOR AGREEMENT

            INTERCREDITOR AGREEMENT dated as of October 6, 1998, among
WILMINGTON TRUST COMPANY, a Delaware banking corporation ("WTC"), not in its
individual capacity but solely as Trustee of each Trust (each as defined below);
ABN AMRO BANK N.V., a bank organized under the laws of the Netherlands, acting
through its Chicago branch ("ABN AMRO"), as Class A Liquidity Provider, as Class
B Liquidity Provider and as Class C Liquidity Provider; and WILMINGTON TRUST
COMPANY, not in its individual capacity except as expressly set forth herein,
but solely as Subordination Agent and trustee hereunder (in such capacity,
together with any successor appointed pursuant to Article VIII hereof, the
"Subordination Agent").

            WHEREAS, all capitalized terms used herein shall have the respective
meanings referred to in Article I hereof;

            WHEREAS, pursuant to each Indenture (i) in the case of each Aircraft
that is owned by America West at the time such Indenture is entered into (the
"Owned Aircraft"), America West will issue on a recourse basis three (or, as
provided herein in certain instances, four) series of Equipment Notes to finance
the purchase of such Aircraft, and (ii) in the case of each Aircraft that is
leased to America West pursuant to a related Lease at the time such Indenture is
entered into (the "Leased Aircraft"), the related Owner Trustee will issue on a
nonrecourse basis three (or, as provided herein in certain instances, four)
series of Equipment Notes to finance the purchase of such Aircraft;

            WHEREAS, pursuant to the Financing Agreements, each Trust will
acquire Equipment Notes having an interest rate equal to the interest rate
applicable to the Certificates to be issued by such Trust;

            WHEREAS, pursuant to each Trust Agreement, the Trust created thereby
proposes to issue a single class of Certificates (a "Class") bearing the
interest rate and having the final distribution date described in such Trust
Agreement on the terms and subject to the conditions set forth therein;

            WHEREAS, pursuant to the Purchase Agreement, the Initial Purchasers
propose to purchase the Certificates issued by each Trust in the aggregate face
amount set forth opposite the name of such Trust on Schedule I thereto on the
terms and subject to the conditions set forth therein;

            WHEREAS, the Liquidity Provider proposes to enter into three
separate revolving credit agreements (each, a "Liquidity Facility") with the
Subordination Agent, as agent for the Trustee of each Trust, respectively, for
the benefit of the Certificateholders of such Trust; and

            WHEREAS, it is a condition precedent to the obligations of the
Initial Purchasers under the Purchase Agreement that the Subordination Agent,
the Trustees and the Liquidity Provider agree to the terms of subordination set
forth in this Agreement in respect of each Class of Certificates, and the
Subordination Agent, the Trustees and the Liquidity Provider, by entering into
this Agreement, hereby acknowledge and agree to such terms of subordination and
the other provisions of this Agreement.
<PAGE>   5
            NOW, THEREFORE, in consideration of the mutual agreements herein
contained, and of other good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, the parties hereto agree as follows:


                                    ARTICLE I

                                   DEFINITIONS

            SECTION 1.1. Definitions. For all purposes of this Agreement, except
as otherwise expressly provided or unless the context otherwise requires:

            (1) the terms used herein that are defined in this Article have the
      meanings assigned to them in this Article, and include the plural as well
      as the singular;

            (2) all references in this Agreement to designated "Articles",
      "Sections" and other subdivisions are to the designated Articles, Sections
      and other subdivisions of this Agreement;

            (3) the words "herein", "hereof" and "hereunder" and other words of
      similar import refer to this Agreement as a whole and not to any
      particular Article, Section or other subdivision; and

            (4) the term "including" shall mean "including without limitation".

            "Acceleration" means, with respect to the amounts payable in respect
of the Equipment Notes issued under any Indenture, such amounts becoming
immediately due and payable by declaration or otherwise. "Accelerate",
"Accelerated" and "Accelerating" have meanings correlative to the foregoing.

            "Adjusted Expected Distributions" means, with respect to the
Certificates of any Trust on any Current Distribution Date, the sum of (x)
accrued and unpaid interest on such Certificates (excluding interest, if any,
payable with respect to the Deposits related to such Trust) and (y) the greater
of:

            (A) the difference between (x) the Pool Balance of such Certificates
      as of the immediately preceding Distribution Date (or, if the Current
      Distribution Date is the first Distribution Date, the original aggregate
      face amount of the Certificates of such Trust) and (y) the Pool Balance of
      such Certificates as of the Current Distribution Date calculated on the
      basis that (i) the principal of the Non-Performing Equipment Notes held in
      such Trust has been paid in full and such payments have been distributed
      to the holders of such Certificates, (ii) the principal of the Performing
      Equipment Notes held in such Trust has been paid when due (but without
      giving effect to any Acceleration of Performing Equipment Notes) and such
      payments have been distributed to the holders of such Certificates and
      (iii) the principal of any Equipment Notes formerly held in such Trust
      that have been sold pursuant to the terms hereof has been paid in full and
      such payments have been distributed to the holders of such Certificates,
      but without giving effect to any reduction in the Pool Balance as a result
      of any distribution attributable to Deposits occurring after the
      immediately preceding Distribution Date (or, if the Current


                                       2
<PAGE>   6
      Distribution Date is the first Distribution Date, occurring after the
      initial issuance of the Certificates of such Trust), and

            (B) the amount of the excess, if any, of (i) the Pool Balance of
      such Class of Certificates as of the immediately preceding Distribution
      Date (or, if the Current Distribution Date is the first Distribution Date,
      the original aggregate face amount of the Certificates of such Trust),
      less the amount of the Deposits for such Class of Certificates as of such
      preceding Distribution Date (or, if the Current Distribution Date is the
      first Distribution Date, the original aggregate amount of the Deposits for
      such Class of Certificates) other than any portion of such Deposits
      thereafter used to acquire Equipment Notes pursuant to the Note Purchase
      Agreement, over (ii) the Aggregate LTV Collateral Amount for such Class of
      Certificates for the Current Distribution Date;

provided that, until the date of the initial LTV Appraisals, clause (B) shall
not apply.

            For purposes of calculating Adjusted Expected Distributions with
respect to the Certificates of any Trust, any premium paid on the Equipment
Notes held in such Trust that has not been distributed to the Certificateholders
of such Trust (other than such premium or a portion thereof applied to the
payment of interest on the Certificates of such Trust or the reduction of the
Pool Balance of such Trust) shall be added to the amount of Adjusted Expected
Distributions.

            "Advance", with respect to any Liquidity Facility, means any
Advances as defined in such Liquidity Facility.

            "Affiliate" means, with respect to any Person, any other Person
directly or indirectly controlling, controlled by or under common control with
such Person. For the purposes of this definition, "control" means the power,
directly or indirectly, to direct or cause the direction of the management and
policies of such Person whether through the ownership of voting securities or by
contract or otherwise; and the terms "controlling" and "controlled" have
meanings correlative to the foregoing.

            "Aggregate LTV Collateral Amount" for any Class of Certificates for
any Distribution Date means the sum of the applicable LTV Collateral Amounts for
each Leased Aircraft and Owned Aircraft, minus the Pool Balance for each Class
of Certificates, if any, senior to such Class, after giving effect to any
distribution of principal on such Distribution Date with respect to such senior
Class or Classes.

            "Aircraft" means, with respect to each Indenture, the "Aircraft"
referred to therein.

            "America West" means America West Airlines, Inc., a Delaware
corporation, and its successors and assigns.

            "America West Bankruptcy Event" means the occurrence and
continuation of any of the following:

            (a) America West shall consent to the appointment of or the taking
      of possession by a receiver, trustee or liquidator of itself or of
      substantially all of its property, or America West shall admit in writing
      its inability to pay its debts generally as


                                       3
<PAGE>   7
      they come due, or shall make a general assignment for the benefit of
      creditors, or America West shall file a voluntary petition in bankruptcy
      or a voluntary petition or an answer seeking reorganization, liquidation
      or other relief in a case under any bankruptcy laws or other insolvency
      laws (as in effect at such time) or an answer admitting the material
      allegations of a petition filed against America West in any such case, or
      America West shall seek relief by voluntary petition, answer or consent,
      under the provisions of any other bankruptcy or other similar law
      providing for the reorganization or winding-up of corporations (as in
      effect at such time) or America West shall seek an agreement, composition,
      extension or adjustment with its creditors under such laws, or America
      West's board of directors shall adopt a resolution authorizing corporate
      action in furtherance of any of the foregoing; or

            (b) an order, judgment or decree shall be entered by any court of
      competent jurisdiction appointing, without the consent of America West, a
      receiver, trustee or liquidator of America West or of substantially all of
      its property, or substantially all of the property of America West shall
      be sequestered, or granting any other relief in respect of America West as
      a debtor under any bankruptcy laws or other insolvency laws (as in effect
      at such time), and any such order, judgment or decree of appointment or
      sequestration shall remain in force undismissed, unstayed and unvacated
      for a period of 90 days after the date of entry thereof; or

            (c) a petition against America West in a case under any bankruptcy
      laws or other insolvency laws (as in effect at such time) is filed and not
      withdrawn or dismissed within 90 days thereafter, or if, under the
      provisions of any law providing for reorganization or winding-up of
      corporations which may apply to America West, any court of competent
      jurisdiction assumes jurisdiction, custody or control of America West or
      of any substantial part of its property and such jurisdiction, custody or
      control remains in force unrelinquished, unstayed and unterminated for a
      period of 90 days.

            "America West Provisions" has the meaning specified in Section
9.1(a).

            "Appraisal" means a fair market value appraisal (which may be a
"desktop" appraisal) performed by any Appraiser or any other nationally
recognized appraiser on the basis of an arm's-length transaction between an
informed and willing purchaser under no compulsion to buy and an informed and
willing seller under no compulsion to sell and both having knowledge of all
relevant facts.

            "Appraised Current Market Value" of any Leased Aircraft or Owned
Aircraft means the lower of the average and the median of the three most recent
Appraisals of such Aircraft.

            "Appraisers" means Aviation Solutions, Inc., BK Associates, Inc.
and AVITAS, Inc.

            "Assignment and Assumption Agreements" means each of the Assignment
and Assumption Agreements to be executed among a Trustee and trustee of the
relevant Successor Trust in accordance with the relevant Trust Agreement, as the
same may be amended, modified or supplemented from time to time.


                                       4
<PAGE>   8
            "Available Amount" means, with respect to any Liquidity Facility on
any drawing date, an amount equal to (a) the Stated Amount of such Liquidity
Facility at such time, less (b) the aggregate amount of each Interest Drawing
honored by the Liquidity Provider under such Liquidity Facility on or prior to
such date which has not been reimbursed or reinstated as of such date; provided
that, following a Downgrade Drawing, a Non-Extension Drawing or a Final Drawing
under such Liquidity Facility, the Available Amount of such Liquidity Facility
shall be zero.

            "Business Day" means any day other than a Saturday or Sunday or a
day on which commercial banks are required or authorized to close in Phoenix,
Arizona, New York, New York, or, so long as any Certificate is outstanding, the
city and state in which any Trustee, the Subordination Agent or any Loan Trustee
maintains its Corporate Trust Office or receives and disburses funds, and that,
solely with respect to draws under any Liquidity Facility, also is a "Business
Day" as defined in such Liquidity Facility.

            "Cash Collateral Account" means the Class A Cash Collateral
Account, the Class B Cash Collateral Account or the Class C Cash Collateral
Account, as applicable.

            "Certificate" means a Class A Certificate, a Class B Certificate or
a Class C Certificate, as applicable.

            "Certificateholder" means any holder of one or more Certificates.

            "Class" has the meaning assigned to such term in the preliminary
statements to this Agreement.

            "Class A Cash Collateral Account" means an Eligible Deposit Account
in the name of the Subordination Agent maintained at an Eligible Institution,
which shall be the Subordination Agent if it shall so qualify, into which all
amounts drawn under the Class A Liquidity Facility pursuant to Section 3.6(c),
3.6(d) or 3.6(i) shall be deposited.

            "Class A Certificateholder" means, at any time, any holder of one or
more Class A Certificates.

            "Class A Certificates" means the certificates issued by the Class A
Trust, substantially in the form of Exhibit A to the Class A Trust Agreement,
and authenticated by the Class A Trustee, representing fractional undivided
interests in the Class A Trust, and any certificates issued in exchange therefor
or replacement thereof pursuant to the terms of the Class A Trust Agreement
and/or the Registration Rights Agreement (including, without limitation, any
Exchange Certificates (as defined in the Class A Trust Agreement)).

            "Class A Liquidity Facility" means, initially, the Revolving Credit
Agreement dated as of the date hereof, between the Subordination Agent, as agent
and trustee for the Class A Trustee, and the initial Class A Liquidity Provider,
and, from and after the replacement of such agreement pursuant hereto, the
Replacement Liquidity Facility therefor, if any, in each case as amended,
supplemented or otherwise modified from time to time in accordance with its
terms.


                                       5
<PAGE>   9
            "Class A Liquidity Provider" means ABN AMRO, together with any
Replacement Liquidity Provider which has issued a Replacement Liquidity Facility
to replace any Class A Liquidity Facility pursuant to Section 3.6(e).

            "Class A Trust" means (i) prior to the Transfer, the America West
Airlines Pass Through Trust 1998-1A-O created and administered pursuant to the
Class A Trust Agreement and (ii) after the Transfer, the America West Airlines
Pass Through Trust 1998-1A-S created and administered pursuant to the Class A
Trust Agreement.

            "Class A Trust Agreement" means (i) prior to the Transfer, the Pass
Through Trust Agreement, dated as of the date hereof, between America West and
the Class A Trustee, governing the creation and administration of the America
West Airlines Pass Through Trust 1998-1A-O and the issuance of the Class A
Certificates, as the same may be amended, supplemented or otherwise modified
from time to time in accordance with its terms, and (ii) after the Transfer, the
Pass Through Trust Agreement entered into between America West and the Class A
Trustee, governing the creation and administration of the America West Airlines
Pass Through Trust 1998-1A-S and the issuance of the Class A Certificates, as
the same may be amended, supplemented or otherwise modified from time to time in
accordance with its terms.

            "Class A Trustee" means WTC, not in its individual capacity except
as expressly set forth in the Class A Trust Agreement, but solely as trustee
under the Class A Trust Agreement, together with any successor trustee appointed
pursuant thereto.

            "Class B Cash Collateral Account" means an Eligible Deposit Account
in the name of the Subordination Agent maintained at an Eligible Institution,
which shall be the Subordination Agent if it shall so qualify, into which all
amounts drawn under the Class B Liquidity Facility pursuant to Section 3.6(c),
3.6(d) or 3.6(i) shall be deposited.

            "Class B Certificateholder" means, at any time, any holder of one or
more Class B Certificates.

            "Class B Certificates" means the certificates issued by the Class B
Trust, substantially in the form of Exhibit A to the Class B Trust Agreement,
and authenticated by the Class B Trustee, representing fractional undivided
interests in the Class B Trust, and any certificates issued in exchange therefor
or replacement thereof pursuant to the terms of the Class B Trust Agreement
and/or the Registration Rights Agreement (including, without limitation, any
Exchange Certificates (as defined in the Class B Trust Agreement)).

            "Class B Liquidity Facility" means, initially, the Revolving Credit
Agreement dated as of the date hereof, between the Subordination Agent, as agent
and trustee for the Class B Trustee, and the initial Class B Liquidity Provider,
and, from and after the replacement of such Agreement pursuant hereto, the
Replacement Liquidity Facility therefor, if any, in each case as amended,
supplemented or otherwise modified from time to time in accordance with its
terms.

            "Class B Liquidity Provider" means ABN AMRO, together with any
Replacement Liquidity Provider which has issued a Replacement Liquidity Facility
to replace any Class B Liquidity Facility pursuant to Section 3.6(e).


                                       6
<PAGE>   10
            "Class B Trust" means (i) prior to the Transfer, the America West
Airlines Pass Through Trust 1998-1B-O created and administered pursuant to the
Class B Trust Agreement and (ii) after the Transfer, the America West Airlines
Pass Through Trust 1998-1B-S created and administered pursuant to the Class B
Trust Agreement.

            "Class B Trust Agreement" means (i) prior to the Transfer, the Pass
Through Trust Agreement, dated as of the date hereof, between America West and
the Class B Trustee, governing the creation and administration of the America
West Airlines Pass Through Trust 1998-1B-O and the issuance of the Class B
Certificates, as the same may be amended, supplemented or otherwise modified
from time to time in accordance with its terms, and (ii) after the Transfer, the
Pass Through Trust Agreement entered into between America West and the Class B
trustee, governing the creation and administration of the America West Airlines
Pass Through Trust 1998-1B-S and the issuance of the Class B Certificates, as
the same may be amended, supplemented or otherwise modified from time to time in
accordance with its terms.

            "Class B Trustee" means WTC, not in its individual capacity except
as expressly set forth in the Class B Trust Agreement, but solely as trustee
under the Class B Trust Agreement, together with any successor trustee appointed
pursuant thereto.

            "Class C Cash Collateral Account" means an Eligible Deposit Account
in the name of the Subordination Agent and maintained at an Eligible
Institution, which shall be the Subordination Agent if it shall so qualify, into
which all amounts drawn under the Class C Liquidity Facility pursuant to Section
3.6(c), 3.6(d) or 3.6(i) shall be deposited.

            "Class C Certificateholder" means, at any time, any holder of one or
more Class C Certificates.

            "Class C Certificates" means the certificates issued by the Class C
Trust, substantially in the form of Exhibit A to the Class C Trust Agreement,
and authenticated by the Class C Trustee, representing fractional undivided
interests in the Class C Trust, and any certificates issued in exchange therefor
or replacement thereof pursuant to the terms of the Class C Trust Agreement
and/or the Registration Rights Agreement (including, without limitation, any
Exchange Certificates (as defined in the Class C Trust Agreement)).

            "Class C Liquidity Facility" means, initially, the Revolving Credit
Agreement dated as of the date hereof, between the Subordination Agent, as agent
and trustee for the Class C Trustee, and the initial Class C Liquidity Provider,
and, from and after the replacement of such Agreement pursuant hereto, the
Replacement Liquidity Facility therefor, if any, in each case as amended,
supplemented or otherwise modified from time to time in accordance with its
terms.

            "Class C Liquidity Provider" means ABN AMRO, together with any
Replacement Liquidity Provider which has issued a Replacement Liquidity Facility
to replace any Class C Liquidity Facility pursuant to Section 3.6(e).

            "Class C Trust" means (i) prior to the Transfer, the America West
Airlines Pass Through Trust 1998-1C-O created and administered pursuant to the
Class C Trust Agreement and (ii) after the Transfer, the America West Airlines
Pass Through Trust 1998-1C-S created and administered pursuant to the Class C
Trust Agreement.


                                       7
<PAGE>   11
            "Class C Trust Agreement" means (i) prior to the Transfer, the Pass
Through Trust Agreement, dated as of the date hereof, between America West and
the Class C Trustee, governing the creation and administration of the America
West Airlines Pass Through Trust 1998-1C-O and the issuance of the Class C
Certificates, as the same may be amended, supplemented or otherwise modified
from time to time in accordance with its terms, and (ii) after the Transfer, the
Pass Through Trust Agreement entered into between America West and the Class C
Trustee, governing the creation and administration of the America West Airlines
Pass Through Trust 1998-1C-S and the issuance of the Class C Certificates, as
the same may be amended, supplemented or otherwise modified from time to time in
accordance with its terms.

            "Class C Trustee" means WTC, not in its individual capacity except
as expressly set forth in the Class C Trust Agreement, but solely as trustee
under the Class C Trust Agreement, together with any successor trustee appointed
pursuant thereto.

            "Class D Certificates" means any pass through certificates issued by
the Class D Trust representing fractional undivided interests in the Class D
Trust.

            "Class D Trust" means the America West Airlines Pass Through Trust
1998-1D, if and when established.

            "Closing Date" means October 6, 1998.

            "Code" means the Internal Revenue Code of 1986, as amended from time
to time, and Treasury Regulations promulgated thereunder.

            "Collection Account" means the Eligible Deposit Account established
by the Subordination Agent pursuant to Section 2.2 which the Subordination Agent
shall make deposits in and withdrawals from in accordance with this Agreement.

            "Controlling Party" means the Person entitled to act as such
pursuant to the terms of Section 2.6.

            "Corporate Trust Office" means, with respect to any Trustee, the
Subordination Agent or any Loan Trustee, the office of such Person in the city
at which, at any particular time, its corporate trust business shall be
principally administered.

            "Current Distribution Date" means a Distribution Date specified as a
reference date for calculating the Expected Distributions or the Adjusted
Expected Distributions with respect to the Certificates of any Trust as of such
Distribution Date.

            "Delivery Period Expiry Date" means the earlier of (a) November 30,
1999, or, if the Equipment Notes relating to all the New Aircraft (or Substitute
Aircraft in lieu thereof) have not been purchased by the Trusts on or prior to
such date due to any reason beyond the control of America West and not
occasioned by America West's fault or negligence, January 31, 2000, and (b) the
date on which Equipment Notes with respect to all New Aircraft (or Substitute
Aircraft in lieu thereof) have been purchased by the Trusts in accordance with
the Note Purchase Agreement.


                                       8
<PAGE>   12
            "Deposit Agreement" shall mean, with respect to any Class, the
Deposit Agreement pertaining to such Class dated the date hereof between the
Escrow Agent, and the Depositary, as the same may be amended, modified or
supplemented from time to time in accordance with the terms thereof.

            "Depositary" means ABN AMRO, as depositary under each Deposit
Agreement.

            "Deposits" with respect to any Class, shall have the meaning set
forth in the Deposit Agreement pertaining to such Class.

            "Designated Representatives" means the Subordination Agent
Representatives, the Trustee Representatives and the LP Representatives
identified under Section 2.5.

            "Distribution Date" means a Regular Distribution Date or a Special
Distribution Date.

            "Dollars" or "$" means United States dollars.

            "Downgrade Drawing" has the meaning assigned to such term in Section
3.6(c).

            "Downgraded Facility" has the meaning assigned to such term in
Section 3.6(c).

            "Drawing" means an Interest Drawing, a Final Drawing, a
Non-Extension Drawing or a Downgrade Drawing, as the case may be.

            "EBO Date" shall mean the date set forth on Schedule 1 to the Lease
as the "EBO Date".

            "Eligible Deposit Account" means either (a) a segregated account
with an Eligible Institution or (b) a segregated trust account with the
corporate trust department of a depository institution organized under the laws
of the United States of America or any one of the states thereof or the District
of Columbia (or any U.S. branch of a foreign bank), having corporate trust
powers and acting as trustee for funds deposited in such account, so long as any
of the securities of such depository institution has a long-term unsecured debt
rating from each Rating Agency of at least A-3 or its equivalent. An Eligible
Deposit Account may be maintained with a Liquidity Provider so long as such
Liquidity Provider is an Eligible Institution; provided that such Liquidity
Provider shall have waived all rights of set-off and counterclaim with respect
to such account; and provided further that no Cash Collateral Account may be
maintained with a Liquidity Provider at any time America West holds any
participation in the related Liquidity Facility unless written confirmation
shall have been received from each Rating Agency prior to such time to the
effect that such maintenance of the Cash Collateral Account with the Liquidity
Provider will not result in a withdrawal or downgrading of the ratings of the
Certificates.

            "Eligible Institution" means (a) the corporate trust department of
the Subordination Agent or any Trustee, as applicable, or (b) a depository
institution organized under the laws of the United States of America or any one
of the states thereof or the District of Columbia (or any U.S. branch of a
foreign bank), which has a long-term unsecured debt rating from each Rating
Agency of at least A-3 or its equivalent; provided that a Liquidity Provider
shall not qualify as an Eligible Institution at any time America West holds any
participation  in


                                       9
<PAGE>   13
the related Liquidity Facility unless written confirmation shall have been
received from each Rating Agency to the effect that such Liquidity Provider's
status as an Eligible Institution will not result in a withdrawal or downgrading
of the ratings of the Certificates.

            "Eligible Investments" means (a) investments in obligations of, or
guaranteed by, the United States Government having maturities no later than 90
days following the date of such investment, (b) investments in open market
commercial paper of any corporation incorporated under the laws of the United
States of America or any state thereof with a short-term unsecured debt rating
issued by Moody's and Standard & Poor's of at least A-1 and P-1, respectively,
having maturities no later than 90 days following the date of such investment or
(c) investments in negotiable certificates of deposit, time deposits, banker's
acceptances, commercial paper or other direct obligations of, or obligations
guaranteed by, commercial banks organized under the laws of the United States or
of any political subdivision thereof (or any U.S. branch of a foreign bank) with
issuer ratings of at least B/C by Thomson Bankwatch, having maturities no later
than 90 days following the date of such investment; provided, however, that (x)
all Eligible Investments that are bank obligations shall be denominated in U.S.
dollars; and (y) the aggregate amount of Eligible Investments at any one time
that are bank obligations issued by any one bank shall not be in excess of 5% of
such bank's capital surplus; provided further that (1) any investment of the
types described in clauses (a), (b) and (c) above may be made through a
repurchase agreement in commercially reasonable form with a bank or other
financial institution qualifying as an Eligible Institution so long as such
investment is held by a third party custodian also qualifying as an Eligible
Institution, and (2) all such investments set forth in clause (a), (b) or (c)
above mature no later than the Business Day immediately preceding the next
Regular Distribution Date; provided further, however, that in the case of any
Eligible Investment issued by a domestic branch of a foreign bank, the income
from such investment shall be from sources within the United States for purposes
of the Code. Notwithstanding the foregoing, no investment of the types described
in clause (b) or (c) above which is issued or guaranteed by a Liquidity Provider
or America West or any of their respective Affiliates, and no investment in the
obligations of any one bank in excess of $10,000,000, shall be an Eligible
Investment at any time America West holds any participation in the related
Liquidity Facility unless written confirmation shall have been received from
each Rating Agency that the making of such investment will not result in a
withdrawal or downgrading of the ratings of the Certificates.

            "Equipment Notes" means, at any time, the Series A Equipment Notes,
the Series B Equipment Notes and the Series C Equipment Notes, collectively, and
in each case, any Equipment Notes issued in exchange therefor or replacement
thereof pursuant to the terms of the Indentures.

            "Escrow Agent" means WTC, as escrow agent under each Escrow and
Paying Agent Agreement, together with its successors in such capacity.

            "Escrow and Paying Agent Agreement" shall mean, with respect to any
Class, the Escrow and Paying Agent Agreement pertaining to such Class dated the
date hereof between the Escrow Agent, the Initial Purchasers, the Trustee for
such Class and the Paying Agent, as the same may be amended, modified or
supplemented from time to time in accordance with the terms thereof.


                                       10
<PAGE>   14
            "Expected Distributions" means, with respect to the Certificates of
any Trust on any Current Distribution Date, the sum of (x) accrued and unpaid
interest on such Certificates (excluding interest, if any, payable with respect
to the Deposits related to such Trust) and (y) the difference between (A) the
Pool Balance of such Certificates as of the immediately preceding Distribution
Date (or, if the Current Distribution Date is the first Distribution Date, the
original aggregate face amount of the Certificates of such Trust) and (B) the
Pool Balance of such Certificates as of the Current Distribution Date calculated
on the basis that (i) the principal of the Equipment Notes held in such Trust
has been paid when due (whether at stated maturity or upon redemption,
prepayment, purchase or Acceleration or otherwise) and such payments have been
distributed to the holders of such Certificates and (ii) the principal of any
Equipment Notes formerly held in such Trust that have been sold pursuant to the
terms hereof has been paid in full and such payments have been distributed to
the holders of such Certificates, but without giving effect to any reduction in
the Pool Balance as a result of any distribution attributable to Deposits
occurring after the immediately preceding Distribution Date (or, if the Current
Distribution Date is the first Distribution Date, occurring after the initial
issuance of the Certificates of such Trust). For purposes of calculating
Expected Distributions with respect to the Certificates of any Trust, any
premium paid on the Equipment Notes held in such Trust which has not been
distributed to the Certificateholders of such Trust (other than such premium or
a portion thereof applied to the payment of interest on the Certificates of such
Trust or the reduction of the Pool Balance of such Trust) shall be added to the
amount of such Expected Distributions.

            "Expiry Date" with respect to any Liquidity Facility, shall have the
meaning set forth in such Liquidity Facility.

            "Fee Letter" means the Fee Letter dated October 6, 1998 among
America West, ABN AMRO and the Subordination Agent with respect to the initial
Liquidity Facilities and any fee letter entered into among America West, the
Subordination Agent and any Replacement Liquidity Provider.

            "Final Distributions" means, with respect to the Certificates of any
Trust on any Distribution Date, the sum of (x) the aggregate amount of all
accrued and unpaid interest on such Certificates (excluding interest, if any,
payable with respect to the Deposits relating to such Trust) and (y) the Pool
Balance of such Certificates as of the immediately preceding Distribution Date
(less the amount of the Deposits for such Class of Certificates as of such
preceding Distribution Date other than any portion of such Deposits thereafter
used to acquire Equipment Notes pursuant to the Note Purchase Agreement). For
purposes of calculating Final Distributions with respect to the Certificates of
any Trust, any premium paid on the Equipment Notes held in such Trust which has
not been distributed to the Certificateholders of such Trust (other than such
premium or a portion thereof applied to the payment of interest on the
Certificates of such Trust or the reduction of the Pool Balance of such Trust)
shall be added to the amount of such Final Distributions.

            "Final Drawing" has the meaning assigned to such term in Section
3.6(i).

            "Final Legal Distribution Date" means (i) with respect to the Class
A Certificates, July 2, 2018, (ii) with respect to the Class B Certificates,
July 2, 2018 and (iii) with respect to the Class C Certificates, January 2,
2012.


                                       11
<PAGE>   15
            "Financing Agreement" means each of the Participation Agreements
and the Note Purchase Agreement.

            "Indenture" means each of the Trust Indentures entered into by the
Loan Trustee, and the Owner Trustee or America West, pursuant to the Note
Purchase Agreement, in each case as the same may be amended, supplemented or
otherwise modified from time to time in accordance with its terms.

            "Indenture Default" means, with respect to any Indenture, any Event
of Default (as such term is defined in such Indenture) thereunder.

            "Initial Purchasers" means Morgan Stanley & Co. Incorporated,
Donaldson, Lufkin & Jenrette Securities Corporation, Merrill Lynch, Pierce,
Fenner & Smith Incorporated and Salomon Smith Barney Inc.

            "Interest Drawing" has the meaning assigned to such term in
Section 3.6(a).

            "Investment Earnings" means investment earnings on funds on deposit
in the Trust Accounts net of losses and investment expenses of the Subordination
Agent in making such investments.

            "Lease" means, with respect to each Indenture pertaining to a Leased
Aircraft, the "Lease" referred to therein.

            "Leased Aircraft" has the meaning assigned to such term in the
preliminary statements of this Agreement.

            "Leased Aircraft Indenture" means, with respect to each Leased
Aircraft, the Indenture pertaining thereto.

            "Lending Office" means, with respect to any Liquidity Facility, the
office of the Liquidity Provider thereunder, presently located at Chicago,
Illinois or such other office as such Liquidity Provider from time to time shall
notify the applicable Trustee as its "Lending Office" under any such Liquidity
Facility; provided that such Liquidity Provider shall not change its Lending
Office to a Lending Office outside the United States of America except in
accordance with Section 3.01, 3.02 or 3.03 of any such Liquidity Facility.

            "Lien" means any mortgage, pledge, lien, charge, claim, disposition
of title, encumbrance, lease, sublease, sub-sublease or security interest of any
kind, including, without limitation, any thereof arising under any conditional
sales or other title retention agreement.

            "Liquidity Event of Default" with respect to any Liquidity Facility,
has the meaning assigned to such term in such Liquidity Facility.

            "Liquidity Expenses" means all Liquidity Obligations other than (i)
the principal amount of any Drawings under the Liquidity Facilities and (ii) any
interest accrued on any Liquidity Obligations.


                                       12
<PAGE>   16
            "Liquidity Facilities" means, at any time, the Class A Liquidity
Facility, the Class B Liquidity Facility or the Class C Liquidity Facility.

            "Liquidity Obligations" means all principal, interest, fees and
other amounts owing to the Liquidity Providers under the Liquidity Facilities,
Section 9.1 of the Participation Agreements or the Fee Letter.

            "Liquidity Provider" means, at any time, any Class A Liquidity
Provider, any Class B Liquidity Provider or any Class C Liquidity Provider, as
applicable.

            "Loan Trustee" means, with respect to any Indenture, the
mortgagee thereunder.

            "LP Incumbency Certificate" has the meaning assigned to such term
in Section 2.5(b).

            "LP Representatives" has the meaning assigned to such term in
Section 2.5(b).

            "LTV Appraisals" has the meaning assigned to such term in Section
4.1(a).

            "LTV Collateral Amount" of any Leased Aircraft or Owned Aircraft for
any Class of Certificates means, as of any Distribution Date, the lesser of (i)
the LTV Ratio for such Class of Certificates multiplied by the Appraised Current
Market Value of such Aircraft (or with respect to any such Aircraft which has
suffered an Event of Loss under and as defined in the relevant Lease (in the
case of a Leased Aircraft) or Indenture (in the case of an Owned Aircraft), the
amount of the insurance proceeds paid to the related Loan Trustee in respect
thereof to the extent then held by such Loan Trustee (and/or on deposit in the
Special Payments Account) or payable to such Loan Trustee in respect thereof)
and (ii) the outstanding principal amount of the Equipment Notes secured by such
Aircraft after giving effect to any principal payments of such Equipment Notes
on or before such Distribution Date.

            "LTV Ratio" means for the Class A Certificates, 43%; for the Class B
Certificates, 57%; and for the Class C Certificates, 71%.

            "Material Adverse Tax Event" has the meaning assigned to such term
in Section 17.3(a)(4) of the Lease.

            "Minimum Sale Price" means, with respect to any Aircraft or the
Equipment Notes issued in respect of such Aircraft, at any time, the lesser of
(a) 75% of the Appraised Current Market Value of such Aircraft and (b) the
aggregate outstanding principal amount of such Equipment Notes, plus accrued and
unpaid interest thereon.

            "Moody's" means Moody's Investors Service, Inc.

            "New Aircraft" shall have the meaning ascribed to the term
"Aircraft" in the Note Purchase Agreement.

            "Non-Controlling Party" means, at any time, any Trustee or Liquidity
Provider which is not the Controlling Party at such time.


                                       13
<PAGE>   17
            "Non-Extended Facility" has the meaning assigned to such term in
Section 3.6(d).

            "Non-Extension Drawing" has the meaning assigned to such term in
Section 3.6(d).

            "Non-Performing Equipment Note" means an Equipment Note issued
pursuant to an Indenture that is not a Performing Equipment Note.

            "Note Purchase Agreement" means the Note Purchase Agreement dated as
of the date hereof, among America West, each Trustee, the Escrow Agent, the
Subordination Agent and the Paying Agent.

            "Officer's Certificate" of any Person means a certification signed
by a Responsible Officer of such Person.

            "Operative Agreements" means this Agreement, the Liquidity
Facilities, the Indentures, the Trust Agreements, the Purchase Agreement, the
Financing Agreements, the Leases, the Fee Letter, the Equipment Notes and the
Certificates, together with all exhibits and schedules included with any of the
foregoing.

            "Outstanding" means, when used with respect to each Class of
Certificates, as of the date of determination, all Certificates of such Class
theretofore authenticated and delivered under the related Trust Agreement,
except:

            (i) Certificates of such Class theretofore canceled by the Registrar
      (as defined in such Trust Agreement) or delivered to the Trustee
      thereunder or such Registrar for cancellation;

           (ii) Certificates of such Class for which money in the full amount
      required to make the final distribution with respect to such Certificates
      pursuant to Section 11.01 of such Trust Agreement has been theretofore
      deposited with the related Trustee in trust for the holders of such
      Certificates as provided in Section 4.01 of such Trust Agreement pending
      distribution of such money to such Certificateholders pursuant to such
      final distribution payment; and

          (iii) Certificates of such Class in exchange for or in lieu of which
      other Certificates have been authenticated and delivered pursuant to such
      Trust Agreement;

provided, however, that in determining whether the holders of the requisite
Outstanding amount of such Certificates have given any request, demand,
authorization, direction, notice, consent or waiver hereunder, any Certificates
owned by America West or any of its Affiliates shall be disregarded and deemed
not to be Outstanding, except that, in determining whether such Trustee shall be
protected in relying upon any such request, demand, authorization, direction,
notice, consent or waiver, only Certificates that such Trustee knows to be so
owned shall be so disregarded. Certificates so owned that have been pledged in
good faith may be regarded as Outstanding if the pledgee establishes to the
satisfaction of the applicable Trustee the pledgee's right so to act with
respect to such Certificates and that the pledgee is not America West or any of
its Affiliates.


                                       14
<PAGE>   18
            "Overdue Scheduled Payment" means any Scheduled Payment which is not
in fact received by the Subordination Agent within five days after the Scheduled
Payment Date relating thereto.

            "Owned Aircraft" has the meaning assigned to such term in the
preliminary statements of this Agreement.

            "Owned Aircraft Indenture" means, with respect to each Owned
Aircraft, the Indenture pertaining to such Aircraft.

            "Owner Trustee" means, with respect to any Indenture pertaining to a
Leased Aircraft, the Owner Trustee (as defined therein) not in its individual
capacity but solely as trustee under the related owner trust agreement, together
with any successor trustee appointed pursuant to such owner trust agreement.

            "Participation Agreement" means, with respect to each Indenture, the
"Participation Agreement" referred to therein.

            "Payee" has the meaning assigned to such term in Section 2.4(e).

            "Paying Agent" means WTC, as paying agent under each Escrow and
Paying Agent Agreement, together with its successors in such capacity.

            "Performing Equipment Note" means an Equipment Note issued pursuant
to an Indenture with respect to which no payment default has occurred and is
continuing (without giving effect to any Acceleration); provided that in the
event of a bankruptcy proceeding involving America West under Title 11 of the
United States Code (the "Bankruptcy Code"), (i) any payment default existing
during the 60-day period under Section 1110(a)(1)(A) of the Bankruptcy Code (or
such longer period as may apply under Section 1110(b) of the Bankruptcy Code)
(the "Section 1110 Period") shall not be taken into consideration, unless during
the Section 1110 Period the trustee in such proceeding or America West refuses
to assume or agree to perform its obligations under the Lease related to such
Equipment Note (in the case of a Leased Aircraft) or under the Indenture related
to such Equipment Note (in the case of an Owned Aircraft) and (ii) any payment
default occurring after the date of the order of relief in such proceeding shall
not be taken into consideration if such payment default is cured under Section
1110(a)(1)(B) of the Bankruptcy Code before the later of 30 days after the date
of such default or the expiration of the Section 1110 Period.

            "Performing Note Deficiency" means any time that less than 65% of
the then aggregate outstanding principal amount of all Equipment Notes are
Performing Equipment Notes.

            "Person" means any individual, corporation, partnership, joint
venture, association, limited liability company, joint-stock company, trust,
trustee, unincorporated organization or government or any agency or political
subdivision thereof.

            "Pool Balance" means, with respect to each Trust or the Certificates
issued by any Trust, as of any date, (i) the original aggregate face amount of
the Certificates of such Trust less (ii) the aggregate amount of all payments
made in respect of the Certificates of such Trust other


                                       15
<PAGE>   19
than payments made in respect of interest or premium thereon or reimbursement of
any costs and expenses in connection therewith less (iii) the aggregate amount
of unused Deposits with respect to such Trust distributed as a Final Withdrawal
(as defined in the Escrow and Paying Agent Agreement related to such Trust)
other than payments in respect of interest or premium thereon. The Pool Balance
for each Trust or for the Certificates issued by any Trust as of any
Distribution Date shall be computed after giving effect to the payment of
principal, if any, of the Equipment Notes or other Trust Property held in such
Trust and the distribution thereof to be made on such date and the distribution
of unused Deposits of such Trust to be made on such date.

            "Proceeding" means any suit in equity, action at law or other
judicial or administrative proceeding.

            "PTC Event of Default" means, with respect to each Trust Agreement,
the failure to pay within 10 Business Days of the due date thereof: (i) the
outstanding Pool Balance of the applicable Class of Certificates on the Final
Legal Distribution Date for such Class or (ii) interest due on such Certificates
on any Distribution Date (unless the Subordination Agent shall have made an
Interest Drawing, or a withdrawal from the Cash Collateral Account, with respect
thereto in an aggregate amount sufficient to pay such interest and shall have
distributed such amount to the Trustee entitled thereto).

            "Purchase Agreement" means the Purchase Agreement dated October 6,
1998 among the Initial Purchasers and America West, relating to the purchase of
the Certificates by the Initial Purchasers, as the same may be amended,
supplemented or otherwise modified from time to time in accordance with its
terms.

            "Rating Agencies" means, collectively, at any time, each nationally
recognized rating agency which shall have been requested to rate the
Certificates and which shall then be rating the Certificates. The initial Rating
Agencies will be Moody's and Standard & Poor's.

            "Ratings Confirmation" means, with respect to any action proposed to
be taken, a written confirmation from each of the Rating Agencies that such
action would not result in (i) a reduction of the rating for any Class of
Certificates below the then current rating for such Class of Certificates or
(ii) a withdrawal or suspension of the rating of any Class of Certificates.

            "Registration Rights Agreement" means the Exchange and Registration
Rights Agreement dated as of the date hereof, among the Initial Purchasers, the
Trustees and America West, as amended, supplemented or otherwise modified from
time to time in accordance with its terms.

            "Regular Distribution Dates" means each January 2 and July 2,
commencing on January 2, 1999; provided, however, that, if any such day shall
not be a Business Day, the related distribution shall be made on the next
succeeding Business Day without additional interest.

            "Replacement Liquidity Facility" means, for any Liquidity Facility,
one or more irrevocable revolving credit agreements issued by one or more
Persons in substantially the form of the initial Liquidity Facility for the
related Trust, including reinstatement provisions, or in such other form (which
may include a letter of credit) as shall permit the Rating Agencies to confirm
in writing their respective ratings then in effect for the related Certificates
(before downgrading of such ratings, if any, as a result of the downgrading of
the applicable Liquidity


                                       16
<PAGE>   20
Provider), in a face amount (or in an aggregate face amount) equal to the amount
of interest payable on the Certificates of such Trust (at the Stated Interest
Rate for such Trust, and without regard to expected future principal payments)
on the three Regular Distribution Dates following the date of replacement of
such Liquidity Facility and issued by a Person (or Persons) having unsecured
short-term debt ratings issued by both Rating Agencies which are equal to or
higher than the Threshold Rating. Without limitation of the form that a
Replacement Liquidity Facility otherwise may have pursuant to the preceding
sentence, a Replacement Liquidity Facility for any Class of Certificates may
have a stated expiration date earlier than 15 days after the Final Legal
Distribution Date of such Class of Certificates so long as such Replacement
Liquidity Facility provides for a Non-Extension Drawing as contemplated by
Section 3.6(d) hereof.

            "Replacement Liquidity Provider" means a Person who issues a
Replacement Liquidity Facility.

            "Required Amount" means, with respect to each Liquidity Facility, or
the Cash Collateral Account, for any Class, for any day, the sum of the
aggregate amount of interest, calculated at the rate per annum equal to the
Stated Interest Rate for the related Class of Certificates, that would be
payable on such Class of Certificates on each of the three successive Regular
Distribution Dates immediately following such day or, if such day is a Regular
Distribution Date, on such day and the succeeding two Regular Distribution
Dates, in each case calculated on the basis of the Pool Balance of such Class of
Certificates on such date and without regard to expected future payments of
principal on such Class of Certificates.

            "Responsible Officer" means (i) with respect to the Subordination
Agent and each of the Trustees, any officer in the corporate trust
administration department of the Subordination Agent or such Trustee or any
other officer customarily performing functions similar to those performed by the
Persons who at the time shall be such officers, respectively, or to whom any
corporate trust matter is referred because of his knowledge of and familiarity
with a particular subject, and (ii) with respect to each Liquidity Provider, any
authorized officer of such Liquidity Provider.

            "Scheduled Payment" means, with respect to any Equipment Note, (i)
any payment of principal or interest on such Equipment Note (other than an
Overdue Scheduled Payment) due from the obligor thereon or (ii) any payment of
interest on the corresponding Class of Certificates with funds drawn under any
Liquidity Facility, which payment represents the installment of principal at the
stated maturity of such installment of principal on such Equipment Note, the
payment of regularly scheduled interest accrued on the unpaid principal amount
of such Equipment Note, or both; provided that any payment of principal of,
premium, if any, or interest resulting from the redemption or purchase of any
Equipment Note shall not constitute a Scheduled Payment.

            "Scheduled Payment Date" means, with respect to any Scheduled
Payment, the date on which such Scheduled Payment is scheduled to be made.

            "Series A Equipment Notes" means the 6.87% Series A Equipment Notes
issued pursuant to each Indenture by the related Owner Trustee or America West,
as the case may be, and authenticated by the Loan Trustee thereunder, and any
such Equipment Notes issued in exchange therefor or replacement thereof pursuant
to the terms of such Indenture.


                                       17
<PAGE>   21
            "Series B Equipment Notes" means the 7.12% Series B Equipment Notes
issued pursuant to each Indenture by the related Owner Trustee or America West,
as the case may be, and authenticated by the Loan Trustee thereunder, and any
such Equipment Notes issued in exchange therefor or replacement thereof pursuant
to the terms of such Indenture.

            "Series C Equipment Notes" means the 7.84% Series C Equipment Notes
issued pursuant to each Indenture by the related Owner Trustee or America West,
as the case may be, and authenticated by the Loan Trustee thereunder, and any
such Equipment Notes issued in exchange therefor or replacement thereof pursuant
to the terms of such Indenture.

            "Special Distribution Date" means, with respect to any Special
Payment, the date chosen by the Subordination Agent pursuant to Section 2.4(a)
for the distribution of such Special Payment in accordance with this Agreement.

            "Special Payment" means any payment (other than a Scheduled Payment)
in respect of, or any proceeds of, any Equipment Note or Trust Indenture Estate
(as defined in each Leased Aircraft Indenture) or Collateral (as defined in each
Owned Aircraft Indenture).

            "Special Payments Account" means the Eligible Deposit Account
created pursuant to Section 2.2 as a sub-account to the Collection Account.

            "Standard & Poor's" means Standard & Poor's Ratings Services, a
division of The McGraw-Hill Companies, Inc.

            "Stated Amount" with respect to any Liquidity Facility, means the
Maximum Commitment (as defined in such Liquidity Facility) of the applicable
Liquidity Provider thereunder.

            "Stated Expiration Date" has the meaning specified in Section
3.6(d).

            "Stated Interest Rate" means (i) with respect to the Class A
Certificates, 6.87% per annum, (ii) with respect to the Class B Certificates,
7.12% per annum, and (iii) with respect to the Class C Certificates, 7.84% per
annum annum (such rate with respect to each Class of Certificates, the "Initial
Stated Interest Rate" for such Class), plus, in each case, solely in the event
no Registration Event (as defined in the Registration Rights Agreement) occurs
on or prior to the 180th day after the Closing Date, an additional margin equal
to 0.50% per annum, from and including such 180th day (provided that any such
additional margin shall cease to be in effect from and including the earlier of
(i) the date on which such Registration Event occurs and (ii) the date on which
there ceases to be any Registrable Certificates (as defined in the Registration
Rights Agreement)); provided that if the Shelf Registration Statement (as
defined in the Registration Rights Agreement) ceases to be effective at any time
during the period specified by Section 2(b)(B) of the Registration Rights
Agreement for more than 60 days, whether or not consecutive, during any 12-month
period, the Stated Interest Rate shall be increased by 0.50% per annum from the
61st day of the applicable 12-month period such Shelf Registration Statement
ceases to be effective until such time as the Shelf Registration Statement again
becomes effective (or, if earlier, the end of the period specified by Section
2(b)(B) of the Registration Rights Agreement). For the avoidance of doubt, the
Stated Interest Rate for any Class of Certificates shall never exceed 0.50% per
annum over the Initial Stated Interest Rate for such Class of Certificates.


                                       18
<PAGE>   22
            "Subordination Agent" has the meaning assigned to it in the
preliminary statements to this Agreement.

            "Subordination Agent Incumbency Certificate" has the meaning
assigned to such term in Section 2.5(a).

            "Subordination Agent Representatives" has the meaning assigned to
such term in Section 2.5(a).

            "Substitute Aircraft" shall have the meaning set forth in the
Note Purchase Agreement.

            "Successor Trusts" means, collectively, America West Airlines Pass
Through Trust 1998-1A-S, America West Airlines Pass Through Trust 1998-1B-S and
America West Airlines Pass Through Trust 1998-1C-S.

            "Tax" and "Taxes" mean any and all taxes, levies, duties, tariffs,
imposts, and other charges of a similar kind (together with any and all
interest, penalties, loss, damage, liability, expense, additions to tax and
additional amounts or costs incurred or imposed with respect thereto) imposed or
otherwise assessed by the United States of America or by any state, local or
foreign government (or any subdivision or agency thereof) or other taxing
authority, including, without limitation: taxes on or with respect to income,
franchises, windfall or other profits, gross receipts, property, sales, use,
capital stock, payroll, employment, social security, workers' compensation,
unemployment compensation, or net worth; taxes in the nature of excise,
withholding, ad valorem, stamp, transfer, non-recoverable value added, taxes on
goods and services and gains taxes.

            "Termination Notice" with respect to any Liquidity Facility has the
meaning assigned to such term in such Liquidity Facility.

            "Threshold Rating" means the short-term unsecured debt rating of P-1
by Moody's and A-1+ by Standard & Poor's, in the case of the Class A Liquidity
Provider and the short-term unsecured debt rating of P-1 by Moody's and A-1 by
Standard & Poor's, in the case of the Class B Liquidity Provider and the Class C
Liquidity Provider.

            "Transfer" means the transfers contemplated by the Assignment and
Assumption Agreements.

            "Treasury Regulations" means regulations, including proposed or
temporary regulations, promulgated under the Code. References herein to specific
provisions of proposed or temporary regulations shall include analogous
provisions of final Treasury Regulations or other successor Treasury
Regulations.

            "Triggering Event" means (x) the occurrence of an Indenture Default
under all of the Indentures resulting in a PTC Event of Default with respect to
the most senior Class of Certificates then Outstanding, (y) the Acceleration of
all of the outstanding Equipment Notes (provided that, with respect to the
period prior to the Delivery Period Expiry Date, the aggregate principal balance
of such Equipment Notes is in excess of $125,000,000) or (z) the occurrence of
an America West Bankruptcy Event.


                                       19
<PAGE>   23
            "Trust" means any of the Class A Trust, the Class B Trust or the
Class C Trust.

            "Trust Accounts" has the meaning assigned to such term in Section
2.2(a).

            "Trust Agreement" means any of the Class A Trust Agreement, the
Class B Trust Agreement or the Class C Trust Agreement.

            "Trust Property" with respect to any Trust, has the meaning set
forth in the Trust Agreement for such Trust.

            "Trustee" means any of the Class A Trustee, the Class B Trustee or
the Class C Trustee.

            "Trustee Incumbency Certificate" has the meaning assigned to such
term in Section 2.5(a).

            "Trustee Representatives" has the meaning assigned to such term
in Section 2.5(a).

            "Unindemnified Tax" means (i) any Tax imposed on the net income, net
worth or capital, any franchise Tax or similar doing business Tax of the
Subordination Agent (other than any such Tax imposed as a result of the
Company's assumption of the Equipment Notes pursuant to the purchase of an
Aircraft on an EBO Date or a Material Adverse Tax Event, and (ii) any
withholding Tax imposed by the United States (including, without limitation, any
withholding Tax imposed by the United States which is imposed or increased as a
result of the Subordination Agent's failing to deliver to the Company any
certificate or document necessary to establish that payments under this
Agreement are exempt from withholding Tax).

            "Written Notice" means, from the Subordination Agent, any Trustee or
Liquidity Provider, a written instrument executed by the Designated
Representative of such Person. An invoice delivered by a Liquidity Provider
pursuant to Section 3.1 in accordance with its normal invoicing procedures shall
constitute Written Notice under such Section.

            "WTC" has the meaning assigned to such term in the recital of
parties to this Agreement.


                                   ARTICLE II

                        TRUST ACCOUNTS; CONTROLLING PARTY

            SECTION 2.1. Agreement to Terms of Subordination; Payments from
Monies Received Only. (a) Each Trustee hereby acknowledges and agrees to the
terms of subordination set forth in this Agreement in respect of each Class of
Certificates and agrees to enforce such provisions and cause all payments in
respect of the Equipment Notes and the Liquidity Facilities to be applied in
accordance with the terms of this Agreement. In addition, each Trustee hereby
agrees to cause the Equipment Notes purchased by the related Trust to be
registered in the name of the Subordination Agent or its nominee, as agent and
trustee for such Trustee, to be held in


                                       20
<PAGE>   24
trust by the Subordination Agent solely for the purpose of facilitating the
enforcement of the subordination and other provisions of this Agreement.

            (b) Except as otherwise expressly provided in the next succeeding
sentence of this Section 2.1, all payments to be made by the Subordination Agent
hereunder shall be made only from amounts received by it that constitute
Scheduled Payments, Special Payments, payments under Section 9.1 of the
Participation Agreements or payments under Sections 6 and 7 of the Note Purchase
Agreement, and only to the extent that the Subordination Agent shall have
received sufficient income or proceeds therefrom to enable it to make such
payments in accordance with the terms hereof. Each of the Trustees and the
Subordination Agent hereby agrees and, as provided in each Trust Agreement, each
Certificateholder, by its acceptance of a Certificate, and each Liquidity
Provider, by entering into the Liquidity Facility to which it is a party, has
agreed to look solely to such amounts to the extent available for distribution
to it as provided in this Agreement and to the relevant Deposits and that none
of the Trustees, Owner Trustees, Loan Trustees, Owner Participants nor the
Subordination Agent or WTC is personally liable to any of them for any amounts
payable or any liability under this Agreement, any Trust Agreement, any
Liquidity Facility or such Certificate, except (in the case of the Subordination
Agent) as expressly provided herein or (in the case of the Trustees) as
expressly provided in each Trust Agreement or (in the case of the Owner Trustees
and the Loan Trustees) as expressly provided in any Operative Agreement.

            SECTION 2.2. Trust Accounts. (a) Upon the execution of this
Agreement, the Subordination Agent shall establish and maintain in its name (i)
the Collection Account as an Eligible Deposit Account, bearing a designation
clearly indicating that the funds deposited therein are held in trust for the
benefit of the Trustees, the Certificateholders and the Liquidity Providers, and
(ii) as a sub-account in the Collection Account, the Special Payments Account as
an Eligible Deposit Account, bearing a designation clearly indicating that the
funds deposited therein are held in trust for the benefit of the Trustees, the
Certificateholders and the Liquidity Providers. The Subordination Agent shall
establish and maintain the Cash Collateral Accounts pursuant to and under the
circumstances set forth in Section 3.6(f) hereof. Upon such establishment and
maintenance under Section 3.6(f) hereof, the Cash Collateral Accounts shall,
together with the Collection Account, constitute the "Trust Accounts" hereunder.

            (b) Funds on deposit in the Trust Accounts shall be invested and
reinvested by the Subordination Agent in Eligible Investments selected by the
Subordination Agent if such investments are reasonably available and have
maturities no later than the earlier of (i) 90 days following the date of such
investment and (ii) the Business Day immediately preceding the Regular
Distribution Date or the date of the related distribution pursuant to Section
2.4 hereof, as the case may be, next following the date of such investment;
provided, however, that following the making of a Downgrade Drawing or a
Non-Extension Drawing under any Liquidity Facility, the Subordination Agent
shall invest and reinvest such amounts in Eligible Investments at the direction
of America West (or, if and to the extent so specified to the Subordination
Agent by America West with respect to any Liquidity Facility, the Liquidity
Provider with respect to such Liquidity Facility); provided further, however,
that following the making of a Downgrade Drawing or Non-Extension Drawing under
any initial Liquidity Facility, the Subordination Agent shall invest and
reinvest the amounts in the Cash Collateral Account with respect to such
Liquidity Facility in Eligible Investments pursuant to the written instructions
of the Liquidity Provider funding such Drawing; provided further, however, that
upon the occurrence and during


                                       21
<PAGE>   25
the continuation of a Triggering Event, the Subordination Agent shall invest and
reinvest such amounts in accordance with the written instructions of the
Controlling Party. Unless otherwise expressly provided in this Agreement
(including, without limitation, with respect to Investment Earnings on amounts
on deposit in the Cash Collateral Accounts, Section 3.6(f) hereof), any
Investment Earnings shall be deposited in the Collection Account when received
by the Subordination Agent and shall be applied by the Subordination Agent in
the same manner as the other amounts on deposit in the Collection Account are to
be applied and any losses shall be charged against the principal amount
invested, in each case net of the Subordination Agent's reasonable fees and
expenses in making such investments. The Subordination Agent shall not be liable
for any loss resulting from any investment, reinvestment or liquidation required
to be made under this Agreement other than by reason of its willful misconduct
or gross negligence. Eligible Investments and any other investment required to
be made hereunder shall be held to their maturities except that any such
investment may be sold (without regard to its maturity) by the Subordination
Agent without instructions whenever such sale is necessary to make a
distribution required under this Agreement. Uninvested funds held hereunder
shall not earn or accrue interest.

            (c) The Subordination Agent shall possess all right, title and
interest in all funds on deposit from time to time in the Trust Accounts and in
all proceeds thereof (including all income thereon, except as otherwise
expressly provided herein with respect to Investment Earnings). The Trust
Accounts shall be held in trust by the Subordination Agent under the sole
dominion and control of the Subordination Agent for the benefit of the Trustees,
the Certificateholders and the Liquidity Providers, as the case may be. If, at
any time, any of the Trust Accounts ceases to be an Eligible Deposit Account,
the Subordination Agent shall within 10 Business Days (or such longer period,
not to exceed 30 calendar days, to which each Rating Agency may consent)
establish a new Collection Account, Special Payments Account or Cash Collateral
Account, as the case may be, as an Eligible Deposit Account and shall transfer
any cash and/or any investments to such new Collection Account, Special Payments
Account or Cash Collateral Account, as the case may be. So long as WTC is an
Eligible Institution, the Trust Accounts shall be maintained with it as Eligible
Deposit Accounts.

            SECTION 2.3.  Deposits to the Collection Account and Special
Payments Account.  (a)  The Subordination Agent shall, upon receipt thereof,
deposit in the Collection Account all Scheduled Payments received by it.

            (b) The Subordination Agent shall, on each date when one or more
Special Payments are made to the Subordination Agent as holder of the Equipment
Notes, deposit in the Special Payments Account the aggregate amount of such
Special Payments.

            SECTION 2.4. Distributions of Special Payments. (a) Notice of
Special Payment. Except as provided in Section 2.4(e) below, upon receipt by the
Subordination Agent, as registered holder of the Equipment Notes, of any notice
of a Special Payment (or, in the absence of any such notice, upon receipt by the
Subordination Agent of a Special Payment), the Subordination Agent shall
promptly give notice thereof to each Trustee and the Liquidity Providers. The
Subordination Agent shall promptly calculate the amount of the redemption or
purchase of Equipment Notes or the amount of any Overdue Scheduled Payment, as
the case may be, comprising such Special Payment under the applicable Indenture
or Indentures and shall promptly send to each Trustee a Written Notice of such
amount and the amount allocable to each


                                       22
<PAGE>   26
Trust. Such Written Notice shall also set the distribution date for such Special
Payment (a "Special Distribution Date"), which shall be the Business Day which
immediately follows the later to occur of (x) the 15th day after the date of
such Written Notice or (y) the date the Subordination Agent has received or
expects to receive such Special Payment. Amounts on deposit in the Special
Payments Account shall be distributed in accordance with Sections 2.4(b) and
2.4(c) hereof, as applicable.

            (b) Redemptions and Purchases of Equipment Notes. (i) So long as no
Triggering Event shall have occurred (whether or not continuing), the
Subordination Agent shall make distributions pursuant to this Section 2.4(b) of
amounts on deposit in the Special Payments Account on account of the redemption,
purchase (including, without limitation, a purchase resulting from a sale of the
Equipment Notes permitted by Article IV hereof) or prepayment of all of the
Equipment Notes issued pursuant to an Indenture on the Special Distribution Date
for such Special Payment in the following order of priority:

            first, such amount as shall be required to pay (A) all accrued and
      unpaid Liquidity Expenses then in arrears plus (B) the product of (x) the
      aggregate amount of all accrued and unpaid Liquidity Expenses not in
      arrears to such Special Payment Date multiplied by (y) a fraction, the
      numerator of which is the aggregate outstanding principal amount of
      Equipment Notes being redeemed, purchased or prepaid on such Special
      Payment Date and the denominator of which is the aggregate outstanding
      principal amount of all Equipment Notes, shall be distributed to the
      Liquidity Providers pari passu on the basis of the amount of Liquidity
      Expenses owed to each Liquidity Provider;

            second, such amount as shall be required to pay (A) all accrued and
      unpaid interest then in arrears on all Liquidity Obligations (including
      interest accrued and unpaid on any Interest Drawing or any Applied
      Provider Advance (as defined in any Liquidity Facility)) plus (B) the
      product of (x) the aggregate amount of all accrued and unpaid interest on
      all Liquidity Obligations not in arrears to such Special Payment Date (at
      the rate provided in the applicable Liquidity Facility) multiplied by (y)
      a fraction, the numerator of which is the aggregate outstanding principal
      amount of Equipment Notes being redeemed, purchased or prepaid on such
      Special Payment Date and the denominator of which is the aggregate
      outstanding principal amount of all Equipment Notes, shall be distributed
      to the Liquidity Providers pari passu on the basis of the amount of such
      Liquidity Obligations owed to each Liquidity Provider;

            third, such amount as shall be required (A) if any Cash Collateral
      Account had been previously funded as provided in Section 3.6(f), to fund
      such Cash Collateral Account up to its Required Amount shall be deposited
      in such Cash Collateral Account, (B) if any Liquidity Facility shall
      become a Downgraded Facility or a Non-Extended Facility at a time when
      unreimbursed Interest Drawings under such Liquidity Facility have reduced
      the Available Amount thereunder to zero, to deposit into the related Cash
      Collateral Account an amount equal to such Cash Collateral Account's
      Required Amount shall be deposited in such Cash Collateral Account, and
      (C) if, with respect to any particular Liquidity Facility, neither
      subclause (A) nor subclause (B) of this clause "third" are applicable, to
      pay or reimburse the Liquidity Provider in respect of such Liquidity
      Facility in an amount equal to the amount of any unreimbursed Interest
      Drawings under


                                       23
<PAGE>   27
      such Liquidity Facility shall be distributed to such Liquidity Provider,
      pari passu on the basis of the amounts of all such deficiencies and/or
      unreimbursed Interest Drawings;

            fourth, if, with respect to any particular Liquidity Facility, any
      amounts are to be distributed pursuant to either subclause (A) or (B) of
      clause "third" above, then the Liquidity Provider with respect to such
      Liquidity Facility shall be paid the excess of (x) the aggregate
      outstanding amount of unreimbursed Advances (whether or not then due)
      under such Liquidity Facility over (y) the Required Amount for the
      relevant Class, pari passu on the basis of such amounts in respect of each
      Liquidity Provider;

            fifth, such amount as shall be required to pay in full Expected
      Distributions to the holders of Class A Certificates on such Special
      Distribution Date shall be distributed to the Class A Trustee;

            sixth, such amount as shall be required to pay in full Expected
      Distributions to the holders of Class B Certificates on such Special
      Distribution Date shall be distributed to the Class B Trustee;

            seventh, such amount as shall be required to pay in full Expected
      Distributions to the holders of Class C Certificates on such Special
      Distribution Date shall be distributed to the Class C Trustee; and

            eighth, the balance, if any, of such Special Payment shall be
      transferred to the Collection Account for distribution in accordance with
      Section 3.2 hereof.

For the purposes of this Section 2.4(b)(i), clause (x) of the definition of
"Expected Distributions" shall be deemed to read as follows: "(x) accrued, due
and unpaid interest on such Certificates together with (without duplication)
accrued and unpaid interest on a portion of such Certificates equal to the
outstanding principal amount of Equipment Notes being redeemed, purchased or
prepaid (immediately prior to such redemption, purchase or prepayment)
(excluding interest, if any, payable with respect to the Deposits related to
such Trust)".

            (ii) Upon the occurrence of a Triggering Event (whether or not
continuing), the Subordination Agent shall make distributions pursuant to this
Section 2.4(b) of amounts on deposit in the Special Payments Account on account
of the redemption or purchase of all of the Equipment Notes issued pursuant to
an Indenture on the Special Distribution Date for such Special Payment in
accordance with Section 3.3 hereof.

            (c) Other Special Payments. Except as provided in clause (e) below,
any amounts on deposit in the Special Payments Account other than in respect of
amounts to be distributed pursuant to Section 2.4(b) shall be distributed on the
Special Distribution Date therefor in accordance with Article III hereof.

            (d) Investment of Amounts in Special Payments Account. Any amounts
on deposit in the Special Payments Account prior to the distribution thereof
pursuant to Section 2.4(b) or (c) shall be invested in accordance with Section
2.2(b). Investment Earnings on such investments shall be distributed in
accordance with Section 2.4(b) or (c), as the case may be.


                                       24
<PAGE>   28
            (e) Certain Payments. The Subordination Agent will distribute
promptly upon receipt thereof (i) any indemnity payment received by it from the
Owner Participant, the Owner Trustee or America West in respect of any Trustee,
any Liquidity Provider, any Paying Agent, any Depositary or any Escrow Agent
(collectively, the "Payees") and (ii) any compensation (including, without
limitation, any fees payable to any Liquidity Provider under Section 2.03 of any
Liquidity Facility) received by it from the Owner Participant, the Owner Trustee
or America West under any Operative Agreement in respect of any Payee, directly
to the Payee entitled thereto.

            SECTION 2.5. Designated Representatives. (a) With the delivery of
this Agreement, the Subordination Agent shall furnish to each Liquidity Provider
and each Trustee, and from time to time thereafter may furnish to each Liquidity
Provider and each Trustee, at the Subordination Agent's discretion, or upon any
Liquidity Provider's or Trustee's request (which request shall not be made more
than one time in any 12-month period), a certificate (a "Subordination Agent
Incumbency Certificate") of a Responsible Officer of the Subordination Agent
certifying as to the incumbency and specimen signatures of the officers of the
Subordination Agent and the attorney-in-fact and agents of the Subordination
Agent (the "Subordination Agent Representatives") authorized to give Written
Notices on behalf of the Subordination Agent hereunder. Until each Liquidity
Provider and Trustee receives a subsequent Subordination Agent Incumbency
Certificate, it shall be entitled to rely on the last Subordination Agent
Incumbency Certificate delivered to it hereunder.

            (b) With the delivery of this Agreement, each Trustee shall furnish
to the Subordination Agent, and from time to time thereafter may furnish to the
Subordination Agent, at such Trustee's discretion, or upon the Subordination
Agent's request (which request shall not be made more than one time in any
12-month period), a certificate (a "Trustee Incumbency Certificate") of a
Responsible Officer of such Trustee certifying as to the incumbency and specimen
signatures of the officers of such Trustee and the attorney-in-fact and agents
of such Trustee (the "Trustee Representatives") authorized to give Written
Notices on behalf of such Trustee hereunder. Until the Subordination Agent
receives a subsequent Trustee Incumbency Certificate, it shall be entitled to
rely on the last Trustee Incumbency Certificate delivered to it hereunder.

            (c) With the delivery of this Agreement, each Liquidity Provider
shall furnish to the Subordination Agent, and from time to time thereafter may
furnish to the Subordination Agent, at such Liquidity Provider's discretion, or
upon the Subordination Agent's request (which request shall not be made more
than one time in any 12-month period), a certificate (an "LP Incumbency
Certificate") of any Responsible Officer of such Liquidity Provider certifying
as to the incumbency and specimen signatures of any officer, attorney-in-fact,
agent or other designated representative of such Liquidity Provider (the "LP
Representatives" and, together with the Subordination Agent Representatives and
the Trustee Representatives, the "Designated Representatives") authorized to
give Written Notices on behalf of such Liquidity Provider hereunder. Until the
Subordination Agent receives a subsequent LP Incumbency Certificate, it shall be
entitled to rely on the last LP Incumbency Certificate delivered to it
hereunder.

            SECTION 2.6. Controlling Party. (a) The Trustees and the Liquidity
Provider hereby agree that, with respect to any Indenture at any given time, the
Loan Trustee thereunder will be directed (i) in taking, or refraining from
taking, any action under such Indenture or with


                                       25
<PAGE>   29
respect to the Equipment Notes issued thereunder, so long as no Indenture
Default has occurred and is continuing thereunder, by the holders of at least a
majority of the outstanding principal amount of such Equipment Notes (provided
that, for so long as the Subordination Agent is the registered holder of the
Equipment Notes, the Subordination Agent shall act with respect to this clause
(i) in accordance with the directions of the Trustees (in the case of each such
Trustee, with respect to the Equipment Notes issued under such Indenture and
held as Trust Property of such Trust) constituting, in the aggregate, directions
with respect to such principal amount of Equipment Notes), and (ii) after the
occurrence and during the continuance of an Indenture Default thereunder (which,
in the case of an Indenture pertaining to a Leased Aircraft, has not been cured
by the applicable Owner Trustee or the applicable Owner Participant, if
applicable, pursuant to Section 4.03 of such Indenture), in taking, or
refraining from taking, any action under such Indenture or with respect to such
Equipment Notes, including exercising remedies thereunder (including
Accelerating the Equipment Notes issued thereunder or foreclosing the Lien on
the Aircraft securing such Equipment Notes), by the Controlling Party.

            (b) The Person who shall be the "Controlling Party" with respect to
any Indenture shall be: (x) the Class A Trustee; (y) upon payment of Final
Distributions to the holders of Class A Certificates, the Class B Trustee; and
(z) upon payment of Final Distributions to the holders of Class B Certificates,
the Class C Trustee. For purposes of giving effect to the foregoing, the
Trustees (other than the Controlling Party) irrevocably agree (and the
Certificateholders (other than the Certificateholders represented by the
Controlling Party) shall be deemed to agree by virtue of their purchase of
Certificates) that the Subordination Agent, as record holder of the Equipment
Notes, shall exercise its voting rights in respect of the Equipment Notes as
directed by the Controlling Party and any vote so exercised shall be binding
upon the Trustees and all Certificateholders.

            The Subordination Agent shall give written notice to all of the
other parties to this Agreement promptly upon a change in the identity of the
Controlling Party. Each of the parties hereto agrees that it shall not exercise
any of the rights of the Controlling Party at such time as it is not the
Controlling Party hereunder; provided, however, that nothing herein contained
shall prevent or prohibit any Non-Controlling Party from exercising such rights
as shall be specifically granted to such Non-Controlling Party hereunder and
under the other Operative Agreements.

            (c) Notwithstanding the foregoing, at any time after 18 months from
the earliest to occur of (i) the date on which the entire Available Amount under
any Liquidity Facility shall have been drawn (for any reason other than a
Downgrade Drawing or a Non-Extension Drawing) and remain unreimbursed, (ii) the
date on which the entire amount of any Downgrade Drawing or Non-Extension
Drawing under any Liquidity Facility shall have become and remain "Applied
Downgrade Advances" or "Applied Non-Extension Advances", as the case may be,
under and as defined in such Liquidity Facility and (iii) the date on which all
Equipment Notes shall have been Accelerated (provided that, with respect to the
period prior to the Delivery Period Expiry Date, such Equipment Notes have an
aggregate outstanding principal balance of in excess of $125,000,000), the
Liquidity Provider with the highest outstanding amount of Liquidity Obligations
shall have the right to elect, by Written Notice to the Subordination Agent and
each of the Trustees, to become the Controlling Party hereunder with respect to
any Indenture at any time from and including the last day of such 18-month
period.


                                       26
<PAGE>   30
            (d) The exercise of remedies by the Controlling Party under this
Agreement shall be expressly limited by Section 4.1(a)(ii) hereof.

            (e) The Controlling Party shall not be entitled to require or
obligate any Non-Controlling Party to provide funds necessary to exercise any
right or remedy hereunder.


                                  ARTICLE III

                     RECEIPT, DISTRIBUTION AND APPLICATION
                              OF AMOUNTS RECEIVED

            SECTION 3.1. Written Notice of Distribution. (a) No later than 3:00
P.M. (New York City time) on the Business Day immediately preceding each Regular
Distribution Date (or Special Distribution Date for purposes of Section 2.4(b)
hereof, as the case may be), each of the following Persons shall deliver to the
Subordination Agent a Written Notice setting forth the following information as
at the close of business on such Business Day:

            (i) With respect to the Class A Certificates, the Class A Trustee
      shall separately set forth the amounts to be paid in accordance with
      clause "fifth" of Section 3.2 or 2.4(b), as the case may be, hereof;

            (ii) With respect to the Class B Certificates, the Class B Trustee
      shall separately set forth the amounts to be paid in accordance with
      clause "sixth" of Section 3.2 or 2.4(b), as the case may be, hereof;

            (iii) With respect to the Class C Certificates, the Class C Trustee
      shall separately set forth the amounts to be paid in accordance with
      clause "seventh" of Section 3.2 or 2.4(b), as the case may be, hereof;

            (iv) With respect to each Liquidity Facility, the Liquidity Provider
      thereunder shall separately set forth the amounts to be paid in accordance
      with clauses "first", "second", "third" and "fourth" of Section 3.2 or
      2.4(b), as the case may be, hereof; and

            (v) Each Trustee shall set forth the amounts to be paid in
      accordance with clause "eighth" of Section 3.2 hereof.

The notices required under this Section 3.1(a) may be in the form of a schedule
or similar document provided to the Subordination Agent by the parties
referenced therein or by any one of them, which schedule or similar document may
state that, unless there has been a prepayment of the Certificates, such
schedule or similar document is to remain in effect until any substitute notice
or amendment shall be given to the Subordination Agent by the party providing
such notice.

            (b) Following the occurrence of a Triggering Event, the
Subordination Agent shall request the following information from the following
Persons, and each of the following Persons shall, upon the request of the
Subordination Agent, deliver a Written Notice to the Subordination Agent setting
forth for such Person the following information:


                                       27
<PAGE>   31
            (i) With respect to the Class A Certificates, the Class A Trustee
      shall separately set forth the amounts to be paid in accordance with
      clauses "first" (to reimburse payments made by the Class A
      Certificateholders pursuant to subclause (iii) of clause "first" of
      Section 3.3 hereof) and "seventh" of Section 3.3 hereof;

            (ii) With respect to the Class B Certificates, the Class B Trustee
      shall separately set forth the amounts to be paid in accordance with
      clauses "first" (to reimburse payments made by the Class B
      Certificateholders pursuant to subclause (iii) of clause "first" of
      Section 3.3 hereof) and "eighth" of Section 3.3 hereof;

            (iii) With respect to the Class C Certificates, the Class C Trustee
      shall separately set forth the amounts to be paid in accordance with
      clauses "first" (to reimburse payments made by the Class C
      Certificateholders pursuant to subclause (iii) of clause "first" of
      Section 3.3 hereof) and "ninth" of Section 3.3 hereof;

            (iv) With respect to each Liquidity Facility, the Liquidity Provider
      thereunder shall separately set forth the amounts to be paid to it in
      accordance with subclause (iii) of clause "first" of Section 3.3 hereof
      and clauses "second", "third", "fourth" and "fifth" of Section 3.3 hereof;
      and

            (v) Each Trustee shall set forth the amounts to be paid in
      accordance with clause "sixth" of Section 3.3 hereof.

            (c) At such time as a Trustee or a Liquidity Provider shall have
received all amounts owing to it (and, in the case of a Trustee, the
Certificateholders for which it is acting) pursuant to Section 2.4, 3.2 or 3.3
hereof, as applicable, and, in the case of a Liquidity Provider, its commitment
under the related Liquidity Facility shall have terminated or expired, such
Person shall, by a Written Notice, so inform the Subordination Agent and each
other party to this Agreement.

            (d) As provided in Section 6.5 hereof, the Subordination Agent shall
be fully protected in relying on any of the information set forth in a Written
Notice provided by any Trustee or any Liquidity Provider pursuant to paragraphs
(a) through (c) above and shall have no independent obligation to verify,
calculate or recalculate any amount set forth in any Written Notice delivered in
accordance with such paragraphs.

            (e) Any Written Notice delivered by a Trustee or a Liquidity
Provider, as applicable, pursuant to Section 3.1(a), 3.1(b) or 3.1(c) hereof, if
made prior to 1:00 P.M. (New York City time) shall be effective on the date
delivered (or if delivered later shall be effective as of the next Business
Day). Subject to the terms of this Agreement, the Subordination Agent shall as
promptly as practicable comply with any such instructions; provided, however,
that any transfer of funds pursuant to any instruction received after 1:00 P.M.
(New York City time) on any Business Day may be made on the next succeeding
Business Day.

            (f) In the event the Subordination Agent shall not receive from any
Person any information set forth in paragraph (a) or (b) above which is required
to enable the Subordination Agent to make a distribution to such Person pursuant
to Section 3.2 or 3.3 hereof, the Subordination Agent shall request such
information and, failing to receive any such information, the Subordination
Agent shall not make such distribution(s) to such Person. In such


                                       28
<PAGE>   32
event, the Subordination Agent shall make distributions pursuant to clauses
"first" through "ninth" of Section 3.2 and clauses "first" through "ninth" of
Section 3.3 to the extent it shall have sufficient information to enable it to
make such distributions, and shall continue to hold any funds remaining, after
making such distributions, until the Subordination Agent shall receive all
necessary information to enable it to distribute any funds so withheld.

            (g) On such dates (but not more frequently than monthly) as any
Liquidity Provider or any Trustee shall request, but in any event automatically
at the end of each calendar quarter, the Subordination Agent shall send to such
party a written statement reflecting all amounts on deposit with the
Subordination Agent pursuant to Section 3.1(f) hereof.

            SECTION 3.2. Distribution of Amounts on Deposit in the Collection
Account. Except as otherwise provided in Sections 2.4, 3.1(f), 3.3, 3.4 and
3.6(b), amounts on deposit in the Collection Account (or, in the case of any
amount described in Section 2.4(c), on deposit in the Special Payments Account)
shall be promptly distributed on each Regular Distribution Date (or, in the case
of any amount described in Section 2.4(c), on the Special Distribution Date
thereof) in the following order of priority and in accordance with the
information provided to the Subordination Agent pursuant to Section 3.1(a)
hereof:

            first, such amount as shall be required to pay all accrued and
      unpaid Liquidity Expenses owed to each Liquidity Provider shall be
      distributed to the Liquidity Providers pari passu on the basis of the
      amount of Liquidity Expenses owed to each Liquidity Provider;

            second, such amount as shall be required to pay in full the
      aggregate amount of interest accrued on all Liquidity Obligations (at the
      rate, or in the amount, provided in the applicable Liquidity Facility) and
      unpaid shall be distributed to the Liquidity Providers pari passu on the
      basis of the amount of such Liquidity Obligations owed to each Liquidity
      Provider;

            third, such amount as shall be required (A) if any Cash Collateral
      Account had been previously funded as provided in Section 3.6(f), to fund
      such Cash Collateral Account up to its Required Amount shall be deposited
      in such Cash Collateral Account, (B) if any Liquidity Facility shall
      become a Downgraded Facility or a Non-Extended Facility at a time when
      unreimbursed Interest Drawings under such Liquidity Facility have reduced
      the Available Amount thereunder to zero, to deposit into the related Cash
      Collateral Account an amount equal to such Cash Collateral Account's
      Required Amount shall be deposited in such Cash Collateral Account, and
      (C) if, with respect to any particular Liquidity Facility, neither
      subclause (A) nor subclause (B) of this clause "third" is applicable, to
      pay or reimburse the Liquidity Provider in respect of such Liquidity
      Facility in an amount equal to the amount of all Liquidity Obligations
      then due under such Liquidity Facility (other than amounts payable
      pursuant to clause "first" or "second" of this Section 3.2) shall be
      distributed to such Liquidity Provider, pari passu on the basis of the
      amounts of all such deficiencies and/or unreimbursed Liquidity
      Obligations;

            fourth, if, with respect to any particular Liquidity Facility, any
      amounts are to be distributed pursuant to either subclause (A) or (B) of
      clause "third" above, then the Liquidity Provider with respect to such
      Liquidity Facility shall be paid the excess of (x)


                                       29
<PAGE>   33
      the aggregate outstanding amount of unreimbursed Advances (whether or not
      then due) under such Liquidity Facility over (y) the Required Amount for
      the relevant Class, pari passu on the basis of such amounts in respect of
      each Liquidity Provider;

            fifth, such amount as shall be required to pay in full Expected
      Distributions to the holders of the Class A Certificates on such
      Distribution Date shall be distributed to the Class A Trustee;

            sixth, such amount as shall be required to pay in full Expected
      Distributions to the holders of the Class B Certificates on such
      Distribution Date shall be distributed to the Class B Trustee;

            seventh, such amount as shall be required to pay in full Expected
      Distributions to the holders of the Class C Certificates on such
      Distribution Date shall be distributed to the Class C Trustee;

            eighth, such amount as shall be required to pay in full the
      aggregate unpaid amount of fees and expenses payable as of such
      Distribution Date to the Subordination Agent and each Trustee pursuant to
      the terms of this Agreement and the Trust Agreements, as the case may be,
      shall be distributed to the Subordination Agent and such Trustee; and

            ninth, the balance, if any, of any such amount remaining thereafter
      shall be held in the Collection Account for later distribution in
      accordance with this Article III.

            SECTION 3.3. Distribution of Amounts on Deposit Following a
Triggering Event. (a) Except as otherwise provided in Sections 3.1(f) and 3.6(b)
hereof, upon the occurrence of a Triggering Event and at all times thereafter,
all funds in the Collection Account or the Special Payments Account shall be
promptly distributed by the Subordination Agent in the following order of
priority:

            first, such amount as shall be required to reimburse (i) the
      Subordination Agent for any reasonable out-of-pocket costs and expenses
      actually incurred by it (to the extent not previously reimbursed) in the
      protection of, or the realization of the value of, the Equipment Notes or
      any Trust Indenture Estate, shall be applied by the Subordination Agent in
      reimbursement of such costs and expenses, (ii) each Trustee for any
      amounts of the nature described in clause (i) above actually incurred by
      it under the applicable Trust Agreement (to the extent not previously
      reimbursed), shall be distributed to such Trustee, and (iii) any Liquidity
      Provider or Certificateholder for payments, if any, made by it to the
      Subordination Agent or any Trustee in respect of amounts described in
      clause (i) above, shall be distributed to such Liquidity Provider or to
      the applicable Trustee for the account of such Certificateholder, in each
      such case, pari passu on the basis of all amounts described in clauses (i)
      through (iii) above;

            second, such amount remaining as shall be required to pay all
      accrued and unpaid Liquidity Expenses shall be distributed to each
      Liquidity Provider pro rata on the basis of the amount of Liquidity
      Expenses owed to each Liquidity Provider;


                                       30
<PAGE>   34
            third, such amount remaining as shall be required to pay accrued and
      unpaid interest on the Liquidity Obligations as provided in the Liquidity
      Facilities shall be distributed to each Liquidity Provider pro rata on the
      basis of the amount of such accrued and unpaid interest owed to each
      Liquidity Provider;

            fourth, such amount remaining as shall be required (A) if any Cash
      Collateral Account had been previously funded as provided in Section
      3.6(f), unless (i) a Performing Note Deficiency exists and a Liquidity
      Event of Default shall have occurred and be continuing with respect to the
      relevant Liquidity Facility or (ii) a Final Drawing shall have occurred
      with respect to such Liquidity Facility, to fund such Cash Collateral
      Account up to its Required Amount (less the amount of any repayments of
      Interest Drawings under such Liquidity Facility while subclause (A)(i)
      above is applicable) shall be deposited in such Cash Collateral Account,
      (B) if any Liquidity Facility shall become a Downgraded Facility or a
      Non-Extended Facility at a time when unreimbursed Interest Drawings under
      such Liquidity Facility have reduced the Available Amount thereunder to
      zero, unless (i) a Performing Note Deficiency exists and a Liquidity Event
      of Default shall have occurred and be continuing with respect to the
      relevant Liquidity Facility or (ii) a Final Drawing shall have occurred
      with respect to such Liquidity Facility, to deposit into the related Cash
      Collateral Account an amount equal to such Cash Collateral Account's
      Required Amount (less the amount of any repayments of Interest Drawings
      under such Liquidity Facility while subclause (B)(i) above is applicable)
      shall be deposited in such Cash Collateral Account, and (C) if, with
      respect to any particular Liquidity Facility, neither subclause (A) nor
      subclause (B) of this clause "fourth" are applicable, to pay in full the
      outstanding amount of all Liquidity Obligations then due under such
      Liquidity Facility (other than amounts payable pursuant to clause "second"
      or "third" of this Section 3.3) shall be distributed to such Liquidity
      Provider, pari passu on the basis of the amounts of all such deficiencies
      and/or unreimbursed Liquidity Obligations;

            fifth, if, with respect to any particular Liquidity Facility, any
      amounts are to be distributed pursuant to either subclause (A) or (B) of
      clause "fourth" above, then the Liquidity Provider with respect to such
      Liquidity Facility shall be paid the excess of (x) the aggregate
      outstanding amount of unreimbursed Advances (whether or not then due)
      under such Liquidity Facility over (y) the Required Amount for the
      relevant Class (less the amount of any repayments of Interest Drawings
      under such Liquidity Facility while subclause (A)(i) or (B)(i), as the
      case may be, of clause "fourth" above is applicable), pari passu on the
      basis of such amounts in respect of each Liquidity Provider;

            sixth, such amount as shall be required to reimburse or pay (i) the
      Subordination Agent for any Tax (other than Unindemnified Taxes), expense,
      fee, charge or other loss reasonably incurred by or any other amount
      payable to the Subordination Agent in connection with the transactions
      contemplated hereby (to the extent not previously reimbursed), shall be
      applied by the Subordination Agent in reimbursement of such amount, (ii)
      each Trustee for any Tax (other than Unindemnified Taxes), expense, fee,
      charge, loss or any other amount payable to such Trustee under the
      applicable Trust Agreements (to the extent not previously reimbursed),
      shall be distributed to such Trustee, and (iii) each Certificateholder for
      payments, if any, made by it pursuant to Section 5.2 hereof in respect of
      amounts described in clause (i) above, shall be distributed


                                       31
<PAGE>   35
      to the applicable Trustee for the account of such Certificateholder, in
      each such case, pari passu on the basis of all amounts described in
      clauses (i) through (iii) above;

            seventh, such amount remaining as shall be required to pay in full
      Adjusted Expected Distributions on the Class A Certificates shall be
      distributed to the Class A Trustee;

            eighth, such amount remaining as shall be required to pay in full
      Adjusted Expected Distributions on the Class B Certificates shall be
      distributed to the Class B Trustee; and

            ninth, such amount remaining as shall be required to pay in full
      Adjusted Expected Distributions on the Class C Certificates shall be
      distributed to the Class C Trustee.

            SECTION 3.4. Other Payments. (a) Any payments received by the
Subordination Agent for which no provision as to the application thereof is made
in this Agreement shall be distributed by the Subordination Agent (i) in the
order of priority specified in Section 3.3 hereof and (ii) to the extent
received or realized at any time after the Final Distributions for each Class of
Certificates have been made, in the manner provided in clause "first" of Section
3.3 hereof.

            (b) Except as otherwise provided in Section 3.3 hereof, if the
Subordination Agent receives any Scheduled Payment after the Scheduled Payment
Date relating thereto, but prior to such payment becoming an Overdue Scheduled
Payment, then the Subordination Agent shall deposit such Scheduled Payment in
the Collection Account and promptly distribute such Scheduled Payment in
accordance with the priority of distributions set forth in Section 3.2 hereof;
provided that, for the purposes of this Section 3.4(c) only, each reference in
clause "eighth" of Section 3.2 to "Distribution Date" shall be deemed to mean
the actual date of payment of such Scheduled Payment and each reference in
clause "fifth", "sixth" or "seventh" of Section 3.2 to "Distribution Date" shall
be deemed to refer to such Scheduled Payment Date.

            SECTION 3.5. Payments to the Trustees and the Liquidity Providers.
Any amounts distributed hereunder to any Liquidity Provider shall be paid to
such Liquidity Provider by wire transfer of funds to the address such Liquidity
Provider shall provide to the Subordination Agent. The Subordination Agent shall
provide a Written Notice of any such transfer to the applicable Liquidity
Provider, as the case may be, at the time of such transfer. Any amounts
distributed hereunder by the Subordination Agent to any Trustee which shall not
be the same institution as the Subordination Agent shall be paid to such Trustee
by wire transfer funds at the address such Trustee shall provide to the
Subordination Agent.

            SECTION 3.6. Liquidity Facilities. (a) Interest Drawings. If on any
Distribution Date, after giving effect to the subordination provisions of this
Agreement, the Subordination Agent shall not have sufficient funds for the
payment of any amounts due and owing in respect of accrued interest on the Class
A Certificates, the Class B Certificates or the Class C Certificates (at the
Stated Interest Rate for such Class of Certificates), then, prior to 1:00 P.M.
(New York City time) on such Distribution Date, the Subordination Agent shall
request a drawing (each such drawing, an "Interest Drawing") under the Liquidity
Facility with respect to


                                       32
<PAGE>   36
such Class of Certificates in an amount equal to the lesser of (i) an amount
sufficient to pay the amount of such accrued interest (at the Stated Interest
Rate for such Class of Certificates) and (ii) the Available Amount under such
Liquidity Facility, and shall pay such amount to the Trustee with respect to
such Class of Certificates in payment of such accrued interest.

            (b) Application of Interest Drawings. Notwithstanding anything to
the contrary contained in this Agreement, (i) all payments received by the
Subordination Agent in respect of an Interest Drawing under the Class A
Liquidity Facility and all amounts withdrawn by the Subordination Agent from the
Class A Cash Collateral Account, and payable in each case to the Class A
Certificateholders, shall be promptly distributed to the Class A Trustee, (ii)
all payments received by the Subordination Agent in respect of an Interest
Drawing under the Class B Liquidity Facility and all amounts withdrawn by the
Subordination Agent from the Class B Cash Collateral Account, and payable in
each case to the Class B Certificateholders, shall be promptly distributed to
the Class B Trustee and (iii) all payments received by the Subordination Agent
in respect of an Interest Drawing under the Class C Liquidity Facility and all
amounts withdrawn by the Subordination Agent from the Class C Cash Collateral
Account, and payable in each case to the Class C Certificateholders, shall be
promptly distributed to the Class C Trustee.

            (c) Downgrade Drawings. If at any time the short-term unsecured debt
rating of any Liquidity Provider issued by either Rating Agency is lower than
the applicable Threshold Rating, within 10 days after receiving notice of such
downgrading (but not later than the expiration date of the Liquidity Facility
issued by the downgraded Liquidity Provider (the "Downgraded Facility")), such
Liquidity Provider or America West may arrange for a Replacement Liquidity
Provider to issue and deliver a Replacement Liquidity Facility to the
Subordination Agent. If a Downgraded Facility has not been replaced in
accordance with the terms of this paragraph, the Subordination Agent shall, on
such 10th day (or if such 10th day is not a Business Day, on the next succeeding
Business Day) (or, if earlier, the expiration date of such Downgraded Facility),
request a drawing in accordance with and to the extent permitted by such
Downgraded Facility (such drawing, a "Downgrade Drawing") of all available and
undrawn amounts thereunder. Amounts drawn pursuant to a Downgrade Drawing shall
be maintained and invested as provided in Section 3.6(f) hereof. The Liquidity
Provider of a Downgraded Facility may also arrange for a Replacement Liquidity
Provider to issue and deliver a Replacement Liquidity Facility at any time after
such Downgrade Drawing so long as such Downgrade Drawing has not been reimbursed
in full to the Liquidity Provider.

            (d) Non-Extension Drawings. If any Liquidity Facility with respect
to any Class of Certificates is scheduled to expire on a date (the "Stated
Expiration Date") prior to the date that is 15 days after the Final Legal
Distribution Date for such Class of Certificates, then, no earlier than the 60th
day and no later than the 40th day prior to the then Stated Expiration Date, the
Subordination Agent shall request that such Liquidity Provider extend the Stated
Expiration Date for a period of 364 days after the Stated Expiration Date
(unless the obligations of such Liquidity Provider thereunder are earlier
terminated in accordance with such Liquidity Facility). The Liquidity Provider
shall advise the Borrower, no earlier than 40 days and no later than 25 days
prior to such Stated Expiration Date, whether, in its sole discretion, it agrees
to so extend the Stated Expiration Date. If, on or before such 25th day, such
Liquidity Facility shall not have been so extended or replaced in accordance
with Section 3.6(e), or if the Liquidity Provider fails irrevocably and
unconditionally to advise the Borrower on or before the 25th day prior to the


                                       33
<PAGE>   37
Stated Expiration Date then in effect that such Stated Expiration Date shall be
so extended, the Subordination Agent shall, on such 25th day (or as soon as
possible thereafter), in accordance with and to the extent permitted by the
terms of the expiring Liquidity Facility (a "Non-Extended Facility"), request a
drawing under such expiring Liquidity Facility (such drawing, a "Non-Extension
Drawing") of all available and undrawn amounts thereunder. Amounts drawn
pursuant to a Non-Extension Drawing shall be maintained and invested in
accordance with Section 3.6(f) hereof.

            (e) Issuance of Replacement Liquidity Facility. (i) At any time,
America West may, at its option, arrange for a Replacement Liquidity Facility to
replace any Liquidity Facility for any Class of Certificates (including any
Replacement Liquidity Facility provided pursuant to Section 3.6(e)(ii) hereof);
provided, however, that the initial Liquidity Provider shall not be replaced by
America West as a Liquidity Provider with respect to any Class of Certificates
prior to the fifth anniversary of the Closing Date unless (A) there shall have
become due to the initial Liquidity Provider, or the initial Liquidity Provider
shall have demanded, amounts pursuant to Section 3.01, 3.02 or 3.03 of any
Liquidity Facility and the replacement of the initial Liquidity Provider would
reduce or eliminate the obligation to pay such amounts or America West
determines in good faith that there is a substantial likelihood that the initial
Liquidity Provider will have the right to claim any such amounts (unless the
initial Liquidity Provider waives, in writing, any right it may have to claim
such amounts), which determination shall be set forth in a certificate delivered
by America West to the initial Liquidity Provider setting forth the basis for
such determination and accompanied by an opinion of outside counsel selected by
America West and reasonably acceptable to the initial Liquidity Provider
verifying the legal conclusions, if any, of such certificate relating to such
basis, provided that, in the case of any likely claim for such amounts based
upon any proposed, or proposed change in, law, rule, regulation, interpretation,
directive, requirement, request or administrative practice, such opinion may
assume the adoption or promulgation of such proposed matter, (B) it shall become
unlawful or impossible for the initial Liquidity Provider (or its Lending
Office) to maintain or fund its LIBOR Advances as described in Section 3.10 of
any Liquidity Facility, (c) the short-term unsecured debt rating of the initial
Liquidity Provider is downgraded by Standard & Poor's from A-1+ to A-1 and there
is a resulting downgrade in the rating by any Rating Agency of any Class of
Certificates, (D) any Liquidity Facility of the initial Liquidity Provider shall
become a Downgraded Facility or a Non-Extended Facility or a Downgrade Drawing
or a Non-Extension Drawing shall have occurred under any Liquidity Facility of
the initial Liquidity Provider or (E) the initial Liquidity Provider shall have
breached any of its payment (including, without limitation, funding) obligations
under any Liquidity Facility. If such Replacement Liquidity Facility is provided
at any time after a Downgrade Drawing or Non-Extension Drawing has been made,
all funds on deposit in the relevant Cash Collateral Account will be returned to
the Liquidity Provider being replaced.

            (ii) If any Liquidity Provider shall determine not to extend any of
      its Liquidity Facility in accordance with Section 3.6(d), then such
      Liquidity Provider may, at its option, arrange for a Replacement Liquidity
      Facility to replace such Liquidity Facility during the period no earlier
      than 40 days and no later than 25 days prior to the then effective Stated
      Expiration Date of such Liquidity Facility.

            (iii) No Replacement Liquidity Facility arranged by America West or
      a Liquidity Provider in accordance with clause (i) or (ii) above or
      pursuant to Section


                                       34
<PAGE>   38
      3.6(c), respectively, shall become effective and no such Replacement
      Liquidity Facility shall be deemed a "Liquidity Facility" under the
      Operative Agreements, unless and until (A) each of the conditions referred
      to in sub-clauses (iv)(x) and (z) below shall have been satisfied and (B)
      in the case of a Replacement Liquidity Facility arranged by a Liquidity
      Provider under Section 3.6(e)(ii) or pursuant to Section 3.6(c), such
      Replacement Liquidity Facility is acceptable to America West.

            (iv) In connection with the issuance of each Replacement Liquidity
      Facility, the Subordination Agent shall (x) prior to the issuance of such
      Replacement Liquidity Facility, obtain written confirmation from each
      Rating Agency that such Replacement Liquidity Facility will not cause a
      reduction of any rating then in effect for any Class of Certificates by
      such Rating Agency (without regard to any downgrading of any rating of any
      Liquidity Provider being replaced pursuant to Section 3.6(c) hereof), (y)
      pay all Liquidity Obligations then owing to the replaced Liquidity
      Provider (which payment shall be made first from available funds in the
      Cash Collateral Account as described in clause (vii) of Section 3.6(f)
      hereof, and thereafter from any other available source, including, without
      limitation, a drawing under the Replacement Liquidity Facility) and (z)
      cause the issuer of the Replacement Liquidity Facility to deliver the
      Replacement Liquidity Facility to the Subordination Agent, together with a
      legal opinion opining that such Replacement Liquidity Facility is an
      enforceable obligation of such Replacement Liquidity Provider.

            (v) Upon satisfaction of the conditions set forth in clauses (iii)
      and (iv) of this Section 3.6(e), (w) the replaced Liquidity Facility shall
      terminate, (x) the Subordination Agent shall, if and to the extent so
      requested by America West or the Liquidity Provider being replaced,
      execute and deliver any certificate or other instrument required in order
      to terminate the replaced Liquidity Facility, shall surrender the replaced
      Liquidity Facility to the Liquidity Provider being replaced and shall
      execute and deliver the Replacement Liquidity Facility and any associated
      Fee Letter, (y) each of the parties hereto shall enter into any amendments
      to this Agreement necessary to give effect to (1) the replacement of the
      applicable Liquidity Provider with the applicable Replacement Liquidity
      Provider and (2) the replacement of the applicable Liquidity Facility with
      the applicable Replacement Liquidity Facility and (z) the applicable
      Replacement Liquidity Provider shall be deemed to be a Liquidity Provider
      with the rights and obligations of a Liquidity Provider hereunder and
      under the other Operative Agreements and such Replacement Liquidity
      Facility shall be deemed to be a Liquidity Facility hereunder and under
      the other Operative Agreements.

            (f) Cash Collateral Accounts; Withdrawals; Investments. In the event
the Subordination Agent shall draw all available amounts under the Class A
Liquidity Facility, the Class B Liquidity Facility or the Class C Liquidity
Facility pursuant to Section 3.6(c), 3.6(d) or 3.6(i) hereof, or in the event
amounts are to be deposited in the Cash Collateral Account pursuant to subclause
(B) of clause "third" of Section 2.4(b), subclause (B) of clause "third" of
Section 3.2 or subclause (B) of clause "fourth" of Section 3.3, amounts so drawn
or to be deposited, as the case may be, shall be deposited by the Subordination
Agent in the Class A Cash Collateral Account, the Class B Cash Collateral
Account or the Class C Cash Collateral Account, respectively. All amounts on
deposit in each Cash Collateral Account shall be invested and reinvested in
Eligible Investments in accordance with Section 2.2(b) hereof. Investment


                                       35
<PAGE>   39
Earnings on amounts on deposit in the Cash Collateral Account with respect to
each Liquidity Facility shall be deposited in the Collection Account on each
Interest Payment Date under such Liquidity Facility and applied on such Interest
Payment Date in accordance with Section 3.2, 3.3 or 3.4 (as applicable). The
Subordination Agent shall deliver a written statement to America West and the
Liquidity Provider one day prior to each Interest Payment Date setting forth the
aggregate amount of Investment Earnings held in the Cash Collateral Accounts as
of such date. In addition, from and after the date funds are so deposited, the
Subordination Agent shall make withdrawals from such account as follows:

            (i) on each Distribution Date, the Subordination Agent shall, to the
      extent it shall not have received funds to pay accrued and unpaid interest
      due and owing on the Class A Certificates (at the Stated Interest Rate for
      the Class A Certificates) from any other source, withdraw from the Class A
      Cash Collateral Account, and pay to the Class A Trustee, an amount equal
      to the lesser of (x) an amount necessary to pay accrued and unpaid
      interest (at the Stated Interest Rate for the Class A Certificates) on
      such Class A Certificates and (y) the amount on deposit in the Class A
      Cash Collateral Account;

            (ii) on each Distribution Date, the Subordination Agent shall, to
      the extent it shall not have received funds to pay accrued and unpaid
      interest due and owing on the Class B Certificates (at the Stated Interest
      Rate for the Class B Certificates) from any other source, withdraw from
      the Class B Cash Collateral Account, and pay to the Class B Trustee, an
      amount equal to the lesser of (x) an amount necessary to pay accrued and
      unpaid interest (at the Stated Interest Rate for the Class B Certificates)
      on such Class B Certificates and (y) the amount on deposit in the Class B
      Cash Collateral Account;

            (iii) on each Distribution Date, the Subordination Agent shall, to
      the extent it shall not have received funds to pay accrued and unpaid
      interest due and owing on the Class C Certificates (at the Stated Interest
      Rate for the Class C Certificates) from any other source, withdraw from
      the Class C Cash Collateral Account, and pay to the Class C Trustee, an
      amount equal to the lesser of (x) an amount necessary to pay accrued and
      unpaid interest (at the Stated Interest Rate for the Class C Certificates)
      on such Class C Certificates and (y) the amount on deposit in the Class C
      Cash Collateral Account;

            (iv) on each date on which the Pool Balance of the Class A Trust
      shall have been reduced by payments made to the Class A Certificateholders
      pursuant to Section 2.4, 3.2 or 3.3 hereof or pursuant to Section 2.03 of
      the Escrow and Paying Agent Agreement for such Class, the Subordination
      Agent shall withdraw from the Class A Cash Collateral Account an amount
      equal to the excess, if any, of the amount on deposit in such Account over
      the Required Amount for such Account and shall first, pay such amount to
      the relevant Class A Liquidity Provider until the Liquidity Obligations
      (with respect to the Class A Certificates) owing to such Liquidity
      Provider shall have been paid in full, and second, deposit any remaining
      amount in the Collection Account;

            (v) on each date on which the Pool Balance of the Class B Trust
      shall have been reduced by payments made to the Class B Certificateholders
      pursuant to Section 2.4, 3.2 or 3.3 hereof or pursuant to Section 2.03 of
      the Escrow and Paying Agent Agreement of such Class, the Subordination
      Agent shall withdraw from the Class B Cash Collateral Account an amount
      equal to the excess, if any, of the amount on deposit in


                                       36
<PAGE>   40
      such Account over the Required Amount for such Account and shall first,
      pay such amount to the relevant Class B Liquidity Provider until the
      Liquidity Obligations (with respect to the Class B Certificates) owing to
      such Liquidity Provider shall have been paid in full, and second, deposit
      any remaining amount in the Collection Account;

            (vi) on each date on which the Pool Balance of the Class C Trust
      shall have been reduced by payments made to the Class C Certificateholders
      pursuant to Section 2.4, 3.2 or 3.3 hereof or pursuant to Section 2.03 of
      the Escrow and Paying Agent Agreement for such Class, the Subordination
      Agent shall withdraw from the Class C Cash Collateral Account an amount
      equal to the excess, if any, of the amount on deposit in such Account over
      the Required Amount for such Account and shall first, pay such amount to
      the relevant Class C Liquidity Provider until the Liquidity Obligations
      (with respect to the Class C Certificates) owing to such Liquidity
      Provider shall have been paid in full, and second, deposit any remaining
      amount in the Collection Account;

            (vii) if a Replacement Liquidity Facility for any Class of
      Certificates shall be delivered to the Subordination Agent following the
      date on which funds have been deposited into the Cash Collateral Account
      for such Class of Certificates, the Subordination Agent shall withdraw all
      amounts on deposit in such Cash Collateral Account and shall pay such
      amounts to the replaced Liquidity Provider until all Liquidity Obligations
      owed to such Person shall have been paid in full, and shall deposit any
      remaining amount in the Collection Account; and

            (viii) following the payment of Final Distributions with respect to
      any Class of Certificates, on the date on which the Subordination Agent
      shall have been notified by the Liquidity Provider for such Class of
      Certificates that the Liquidity Obligations owed to such Liquidity
      Provider have been paid in full, the Subordination Agent shall withdraw
      all amounts on deposit in the Cash Collateral Account in respect of such
      Class of Certificates and shall deposit such amount in the Collection
      Account.

            (g) Reinstatement. With respect to any Interest Drawing under the
Liquidity Facility for any Trust, upon the reimbursement of the applicable
Liquidity Provider for all or any part of the amount of such Interest Drawing,
together with any accrued interest thereon, the Available Amount of such
Liquidity Facility shall be reinstated by an amount equal to the amount of such
Interest Drawing so reimbursed to the applicable Liquidity Provider but not to
exceed the Stated Amount for such Liquidity Facility; provided, however, that
such Liquidity Facility shall not be so reinstated in part or in full at any
time if (x) both a Performing Note Deficiency exists and a Liquidity Event of
Default shall have occurred and be continuing with respect to the relevant
Liquidity Facility or (y) a Final Drawing shall have occurred with respect to
such Liquidity Facility. In the event that, with respect to any particular
Liquidity Facility, (i) funds are withdrawn from any Cash Collateral Account
pursuant to clause (i), (ii) or (iii) of Section 3.6(f) hereof or (ii) such
Liquidity Facility shall become a Downgraded Facility or a Non-Extended Facility
at a time when unreimbursed Interest Drawings under such Liquidity Facility have
reduced the Available Amount thereunder to zero, then funds received by the
Subordination Agent at any time other than (x) any time when a Liquidity Event
of Default shall have occurred and be continuing with respect to such Liquidity
Facility and a Performing Note Deficiency exists or (y) any time after a Final
Drawing shall have occurred with respect to such Liquidity Facility shall be
deposited in such Cash Collateral Account as and to the extent


                                       37
<PAGE>   41
provided in clause "third" of Section 2.4(b), clause "third" of Section 3.2 or
clause "fourth" of Section 3.3, as applicable, and applied in accordance with
Section 3.6(f) hereof.

            (h) Reimbursement. The amount of each drawing under the Liquidity
Facilities shall be due and payable, together with interest thereon, on the
dates and at the rates, respectively, provided in the Liquidity Facilities.

            (i) Final Drawing. Upon receipt from a Liquidity Provider of a
Termination Notice with respect to any Liquidity Facility, the Subordination
Agent shall, not later than the date specified in such Termination Notice, in
accordance with and to the extent permitted by the terms of such Liquidity
Facility, request a drawing under such Liquidity Facility of all available and
undrawn amounts thereunder (a "Final Drawing"). Amounts drawn pursuant to a
Final Drawing shall be maintained and invested in accordance with Section 3.6(f)
hereof.

            (j) Reduction of Stated Amount. Promptly following each date on
which the Required Amount of the Liquidity Facility for a Class of Certificates
is reduced as a result of a reduction in the Pool Balance with respect to such
Certificates, the Subordination Agent shall, if any such Liquidity Facility
provides for reductions of the Stated Amount of such Liquidity Facility and if
such reductions are not automatic, request such Liquidity Provider for such
Class of Certificates to reduce such Stated Amount to an amount equal to the
Required Amount with respect to such Liquidity Facility (as calculated by the
Subordination Agent after giving effect to such payment). Each such request
shall be made in accordance with the provisions of the applicable Liquidity
Facility.

            (k) Relation to Subordination Provisions. Interest Drawings under
the Liquidity Facilities and withdrawals from the Cash Collateral Accounts, in
each case, in respect of interest on the Certificates of any Class, will be
distributed to the Trustee for such Class of Certificates, notwithstanding
Sections 3.2, 3.3 and 3.6(h) hereof.

            (l) Assignment of Liquidity Facility. The Subordination Agent agrees
not to consent to the assignment by any Liquidity Provider of any of its rights
or obligations under any Liquidity Facility or any interest therein, unless (i)
America West shall have consented to such assignment, such consent to be within
America West's sole discretion, and (ii) each Rating Agency shall have provided
a Ratings Confirmation in respect of such assignment and, upon the satisfaction
of (i) and (ii), the Subordination Agent shall give such consent.


                                   ARTICLE IV

                              EXERCISE OF REMEDIES

            SECTION 4.1. Directions from the Controlling Party. (a) (i)
Following the occurrence and during the continuation of an Indenture Default
under any Indenture, the Controlling Party shall direct the Subordination Agent,
which in turn shall direct the Loan Trustee under such Indenture, in the
exercise of remedies available to the holders of the Equipment Notes issued
pursuant to such Indenture, including, without limitation, the ability to vote
all such Equipment Notes in favor of Accelerating such Equipment Notes in
accordance with the provisions of such Indenture. Subject to the Owner Trustees'
and the Owner Participants' rights, if any, set forth in the Indentures with
respect to Leased Aircraft to purchase


                                       38
<PAGE>   42
the Equipment Notes and the provisions of the next paragraph, if the Equipment
Notes issued pursuant to any Indenture have been Accelerated following an
Indenture Default with respect thereto, the Controlling Party may sell, assign,
contract to sell or otherwise dispose of and deliver all (but not less than all)
of such Equipment Notes to any Person at public or private sale, at any location
at the option of the Controlling Party, all upon such terms and conditions as it
may reasonably deem advisable in accordance with applicable law.

           (ii) Subject to the Owner Trustees' and the Owner Participants'
      rights, if any, set forth in the Indentures with respect to Leased
      Aircraft to purchase the Equipment Notes, and notwithstanding the
      foregoing, so long as any Certificates remain Outstanding, during the
      period ending on the date which is nine months after the earlier of (x)
      the Acceleration of the Equipment Notes issued pursuant to any Indenture
      or (y) the occurrence of an America West Bankruptcy Event, without the
      consent of each Trustee, (A) no Aircraft subject to the Lien of such
      Indenture or such Equipment Notes may be sold if the net proceeds from
      such sale would be less than the Minimum Sale Price for such Aircraft or
      such Equipment Notes, and (B) with respect to any Leased Aircraft, the
      amount and payment dates of rentals payable by America West under the
      Lease for such Aircraft may not be adjusted, if, as a result of such
      adjustment, the discounted present value of all such rentals would be less
      than 75% of the discounted present value of the rentals payable by America
      West under such Lease before giving effect to such adjustment, in each
      case, using the weighted average interest rate of the Equipment Notes
      issued pursuant to such Indenture as the discount rate.

          (iii) At the request of the Controlling Party, the Subordination Agent
      may from time to time during the continuance of an Indenture Default (and
      before the occurrence of a Triggering Event) commission LTV Appraisals
      with respect to the Aircraft subject to such Indenture.

           (iv) After a Triggering Event occurs and any Equipment Note becomes a
      Non-Performing Equipment Note, the Subordination Agent shall obtain
      Appraisals with respect to all of the Aircraft (the "LTV Appraisals") as
      soon as practicable and additional LTV Appraisals on or prior to each
      anniversary of the date of such initial LTV Appraisals; provided that if
      the Controlling Party reasonably objects to the appraised value of the
      Aircraft shown in such LTV Appraisals, the Controlling Party shall have
      the right to obtain or cause to be obtained substitute LTV Appraisals
      (including any LTV Appraisals based upon physical inspection of the
      Aircraft).

            (b) The Controlling Party shall take such actions as it may
reasonably deem most effectual to complete the sale or other disposition of such
Aircraft or Equipment Notes. In addition, in lieu of any sale, assignment,
contract to sell or other disposition, the Controlling Party may maintain
possession of such Equipment Notes and continue to apply monies received in
respect of such Equipment Notes in accordance with Article III hereof. In
addition, in lieu of such sale, assignment, contract to sell or other
disposition, or in lieu of such maintenance of possession, the Controlling Party
may, subject to the terms and conditions of the related Indenture, instruct the
Loan Trustee under such Indenture to foreclose on the Lien on the related
Aircraft.


                                       39
<PAGE>   43
            SECTION 4.2. Remedies Cumulative. Each and every right, power and
remedy given to the Trustees, the Liquidity Providers, the Controlling Party or
the Subordination Agent specifically or otherwise in this Agreement shall be
cumulative and shall be in addition to every other right, power and remedy
herein specifically given or now or hereafter existing at law, in equity or by
statute, and each and every right, power and remedy whether specifically herein
given or otherwise existing may, subject always to the terms and conditions
hereof, be exercised from time to time and as often and in such order as may be
deemed expedient by any Trustee, any Liquidity Provider, the Controlling Party
or the Subordination Agent, as appropriate, and the exercise or the beginning of
the exercise of any power or remedy shall not be construed to be a waiver of the
right to exercise at the same time or thereafter any other right, power or
remedy. No delay or omission by any Trustee, any Liquidity Provider, the
Controlling Party or the Subordination Agent in the exercise of any right,
remedy or power or in the pursuit of any remedy shall impair any such right,
power or remedy or be construed to be a waiver of any default or to be an
acquiescence therein.

            SECTION 4.3. Discontinuance of Proceedings. In case any party to
this Agreement (including the Controlling Party in such capacity) shall have
instituted any Proceeding to enforce any right, power or remedy under this
Agreement by foreclosure, entry or otherwise, and such Proceeding shall have
been discontinued or abandoned for any reason or shall have been determined
adversely to the Person instituting such Proceedings, then and in every such
case each such party shall, subject to any determination in such Proceeding, be
restored to its former position and rights hereunder, and all rights, remedies
and powers of such party shall continue as if no such Proceeding had been
instituted.

            SECTION 4.4. Right of Certificateholders to Receive Payments Not to
Be Impaired. Anything in this Agreement to the contrary notwithstanding but
subject to each Trust Agreement, the right of any Certificateholder or any
Liquidity Provider, respectively, to receive payments hereunder (including
without limitation pursuant to Section 2.4, 3.2 or 3.3 hereof) when due, or to
institute suit for the enforcement of any such payment on or after the
applicable Distribution Date, shall not be impaired or affected without the
consent of such Certificateholder or such Liquidity Provider, respectively.

            SECTION 4.5. Undertaking for Costs. In any Proceeding for the
enforcement of any right or remedy under this Agreement or in any Proceeding
against any Controlling Party or the Subordination Agent for any action taken or
omitted by it as Controlling Party or Subordination Agent, as the case may be, a
court in its discretion may require the filing by any party litigant in the suit
of an undertaking to pay the costs of the suit, and the court in its discretion
may assess reasonable costs, including reasonable attorneys' fees and expenses,
against any party litigant in the suit, having due regard to the merits and good
faith of the claims or defenses made by the party litigant. The provisions of
this Section do not apply to a suit instituted by the Subordination Agent, a
Liquidity Provider or a Trustee or a suit by Certificateholders holding more
than 10% of the original principal amount of any Class of Certificates.


                                    ARTICLE V

                       DUTIES OF THE SUBORDINATION AGENT;
                          AGREEMENTS OF TRUSTEES, ETC.


                                       40
<PAGE>   44
            SECTION 5.1. Notice of Indenture Default or Triggering Event. (a) In
the event the Corporate Trust Office of the Subordination Agent shall have
actual knowledge of the occurrence of an Indenture Default or a Triggering
Event, as promptly as practicable, and in any event within 10 days after
obtaining knowledge thereof, the Subordination Agent shall transmit by mail or
courier to the Rating Agencies, the Liquidity Providers and the Trustees notice
of such Indenture Default or Triggering Event, unless such Indenture Default or
Triggering Event shall have been cured or waived. For all purposes of this
Agreement, in the absence of actual knowledge on the part of a Responsible
Officer, the Subordination Agent shall not be deemed to have knowledge of any
Indenture Default or Triggering Event unless notified in writing by one or more
Trustees, one or more Liquidity Providers or one or more Certificateholders.

            (b) Other Notices. The Subordination Agent will furnish to each
Liquidity Provider and Trustee, promptly upon receipt thereof by its Corporate
Trust Office, duplicates or copies of all reports, notices, requests, demands,
certificates, financial statements and other instruments furnished to the
Subordination Agent as registered holder of the Equipment Notes or otherwise in
its capacity as Subordination Agent to the extent the same shall not have been
otherwise directly distributed to such Liquidity Provider or Trustee, as
applicable, pursuant to the express provision of any other Operative Agreement.

            SECTION 5.2. Indemnification. The Subordination Agent shall not be
required to take any action or refrain from taking any action under Article IV
hereof unless the Subordination Agent and WTC shall have been indemnified (to
the extent and in the manner reasonably satisfactory to the Subordination Agent)
against any liability, cost or expense (including counsel fees and expenses)
which may be incurred in connection therewith. The Subordination Agent shall not
be under any obligation to take any action under this Agreement and nothing
contained in this Agreement shall require the Subordination Agent to expend or
risk its own funds or otherwise incur any financial liability in the performance
of any of its duties hereunder or in the exercise of any of its rights or powers
if it shall have reasonable grounds for believing that repayment of such funds
or adequate indemnity against such risk or liability is not reasonably assured
to it. The Subordination Agent shall not be required to take any action under
Article IV hereof, nor shall any other provision of this Agreement be deemed to
impose a duty on the Subordination Agent to take any action, if the
Subordination Agent shall have been advised by counsel that such action is
contrary to the terms hereof or is otherwise contrary to law.

            SECTION 5.3. No Duties Except as Specified in Intercreditor
Agreement. The Subordination Agent shall not have any duty or obligation to take
or refrain from taking any action under, or in connection with, this Agreement,
except as expressly provided by the terms of this Agreement; and no implied
duties or obligations shall be read into this Agreement against the
Subordination Agent. The Subordination Agent agrees that it will, in its
individual capacity and at its own cost and expense (but without any right of
indemnity in respect of any such cost or expense under Section 7.1 hereof),
promptly take such action as may be necessary to duly discharge all Liens on any
of the Trust Accounts or any monies deposited therein which result from claims
against it in its individual capacity not related to its activities hereunder or
any other Operative Agreement.

            SECTION 5.4. Notice from the Liquidity Providers and Trustees. If
the Corporate Trust Office of any Liquidity Provider or Trustee has notice of an
Indenture Default or


                                       41
<PAGE>   45
a Triggering Event, such Person shall promptly give notice thereof to all other
Liquidity Providers and Trustees and to the Subordination Agent, provided,
however, that no such Person shall have any liability hereunder as a result of
its failure to deliver any such notice.


                                   ARTICLE VI

                             THE SUBORDINATION AGENT

            SECTION 6.1. Authorization; Acceptance of Trusts and Duties. Each of
the Class A Trustee, the Class B Trustee and the Class C Trustee hereby
designates and appoints the Subordination Agent as the agent and trustee of such
Trustee under the applicable Liquidity Facility and authorizes the Subordination
Agent to enter into the applicable Liquidity Facility as agent and trustee for
such Trustee. Each of the Liquidity Providers and the Trustees hereby designates
and appoints the Subordination Agent as the Subordination Agent under this
Agreement. WTC hereby accepts the duties hereby created and applicable to it as
the Subordination Agent and agrees to perform the same but only upon the terms
of this Agreement and agrees to receive and disburse all monies received by it
in accordance with the terms hereof. The Subordination Agent shall not be
answerable or accountable under any circumstances, except (a) for its own
willful misconduct or gross negligence (or ordinary negligence in the handling
of funds), (b) as provided in Sections 2.2 and 5.3 hereof and (c) for
liabilities that may result from the inaccuracy of any representation or
warranty of the Subordination Agent made in its individual capacity in any
Operative Agreement. The Subordination Agent shall not be liable for any error
of judgment made in good faith by a Responsible Officer of the Subordination
Agent, unless it is proved that the Subordination Agent was negligent in
ascertaining the pertinent facts.

            SECTION 6.2. Absence of Duties. The Subordination Agent shall have
no duty to see to any recording or filing of this Agreement or any other
document, or to see to the maintenance of any such recording or filing.

            SECTION 6.3. No Representations or Warranties as to Documents. The
Subordination Agent in its individual capacity does not make nor shall be deemed
to have made any representation or warranty as to the validity, legality or
enforceability of this Agreement or any other Operative Agreement or as to the
correctness of any statement contained in any thereof, except for the
representations and warranties of the Subordination Agent, made in its
individual capacity, under any Operative Agreement to which it is a party. The
Certificateholders, the Trustees and the Liquidity Providers make no
representation or warranty hereunder whatsoever.

            SECTION 6.4. No Segregation of Monies; No Interest. Any monies paid
to or retained by the Subordination Agent pursuant to any provision hereof and
not then required to be distributed to any Trustee or any Liquidity Provider as
provided in Articles II and III hereof or deposited into one or more Trust
Accounts need not be segregated in any manner except to the extent required by
such Articles II and III and by law, and the Subordination Agent shall not
(except as otherwise provided in Section 2.2 hereof) be liable for any interest
thereon; provided, however, that any payments received or applied hereunder by
the Subordination Agent shall be accounted for by the Subordination Agent so
that any portion thereof paid or applied pursuant hereto shall be identifiable
as to the source thereof.


                                       42
<PAGE>   46
            SECTION 6.5. Reliance; Agents; Advice of Counsel. The Subordination
Agent shall not incur liability to anyone in acting upon any signature,
instrument, notice, resolution, request, consent, order, certificate, report,
opinion, bond or other document or paper believed by it to be genuine and
believed by it to be signed by the proper party or parties. As to the Pool
Balance of any Trust as of any date, the Subordination Agent may for all
purposes hereof rely on a certificate signed by any Responsible Officer of the
applicable Trustee, and such certificate shall constitute full protection to the
Subordination Agent for any action taken or omitted to be taken by it in good
faith in reliance thereon. As to any fact or matter relating to the Liquidity
Providers or the Trustees the manner of ascertainment of which is not
specifically described herein, the Subordination Agent may for all purposes
hereof rely on a certificate, signed by any Responsible Officer of the
applicable Liquidity Provider or Trustee, as the case may be, as to such fact or
matter, and such certificate shall constitute full protection to the
Subordination Agent for any action taken or omitted to be taken by it in good
faith in reliance thereon. The Subordination Agent shall assume, and shall be
fully protected in assuming, that each of the Liquidity Providers and each of
the Trustees are authorized to enter into this Agreement and to take all action
to be taken by them pursuant to the provisions hereof, and shall not inquire
into the authorization of each of the Liquidity Providers and each of the
Trustees with respect thereto. In the administration of the trusts hereunder,
the Subordination Agent may execute any of the trusts or powers hereof and
perform its powers and duties hereunder directly or through agents or attorneys
and may consult with counsel, accountants and other skilled persons to be
selected and retained by it, and the Subordination Agent shall not be liable for
the acts or omissions of any agent appointed with due care or for anything done,
suffered or omitted in good faith by it in accordance with the advice or written
opinion of any such counsel, accountants or other skilled persons.

            SECTION 6.6. Capacity in Which Acting. The Subordination Agent acts
hereunder solely as agent and trustee herein and not in its individual capacity,
except as otherwise expressly provided in the Operative Agreements.

            SECTION 6.7. Compensation. The Subordination Agent shall be entitled
to reasonable compensation, including reimbursement for reasonable expenses and
disbursements, except with respect to any Unindemnified Taxes incurred by the
Subordination Agent in connection with the transactions contemplated by this
Agreement, for all services rendered hereunder and shall have a priority claim
to the extent set forth in Article III hereof on all monies collected hereunder
for the payment of such compensation (other than any Unindemnified Taxes), to
the extent that such compensation shall not be paid by others. The Subordination
Agent agrees that it shall have no right against any Trustee or Liquidity
Provider for any fee as compensation for its services as agent under this
Agreement. The provisions of this Section 6.7 shall survive the termination of
this Agreement.

            SECTION 6.8. May Become Certificateholder. The institution acting as
Subordination Agent hereunder may become a Certificateholder and have all rights
and benefits of a Certificateholder to the same extent as if it were not the
institution acting as the Subordination Agent.

            SECTION 6.9. Subordination Agent Required; Eligibility. There shall
at all times be a Subordination Agent hereunder which shall be a corporation
organized and doing business under the laws of the United States of America or
of any State or the District of


                                       43
<PAGE>   47
Columbia having a combined capital and surplus of at least $100,000,000 (or the
obligations of which, whether now in existence or hereafter incurred, are fully
and unconditionally guaranteed by a corporation organized and doing business
under the laws of the United States of America, any State thereof or of the
District of Columbia and having a combined capital and surplus of at least
$100,000,000), if there is such an institution willing and able to perform the
duties of the Subordination Agent hereunder upon reasonable or customary terms.
Such corporation shall be a citizen of the United States and shall be authorized
under the laws of the United States or any State thereof or of the District of
Columbia to exercise corporate trust powers and shall be subject to supervision
or examination by federal, state or District of Columbia authorities. If such
corporation publishes reports of condition at least annually, pursuant to law or
to the requirements of any of the aforesaid supervising or examining
authorities, then, for the purposes of this Section 6.9, the combined capital
and surplus of such corporation shall be deemed to be its combined capital and
surplus as set forth in its most recent report of condition so published.

            In case at any time the Subordination Agent shall cease to be
eligible in accordance with the provisions of this Section, the Subordination
Agent shall resign immediately in the manner and with the effect specified in
Section 8.1.

            SECTION 6.10. Money to Be Held in Trust. All Equipment Notes, monies
and other property deposited with or held by the Subordination Agent pursuant to
this Agreement shall be held in trust for the benefit of the parties entitled to
such Equipment Notes, monies and other property. All such Equipment Notes,
monies or other property shall be held in the Trust Department of the
institution acting as Subordination Agent hereunder.


                                   ARTICLE VII

                     INDEMNIFICATION OF SUBORDINATION AGENT

            SECTION 7.1. Scope of Indemnification. The Subordination Agent shall
be indemnified hereunder to the extent and in the manner described in Section
9.1 of the Participation Agreements and Section 6 of the Note Purchase
Agreement. The indemnities contained in such Sections of such agreements shall
survive the resignation or removal of the Subordination Agent and the
termination of this Agreement.


                                  ARTICLE VIII

                          SUCCESSOR SUBORDINATION AGENT

            SECTION 8.1. Replacement of Subordination Agent; Appointment of
Successor. The Subordination Agent may resign at any time by so notifying the
Trustees and the Liquidity Providers. The Controlling Party may remove the
Subordination Agent for cause by so notifying the Subordination Agent and may
appoint a successor Subordination Agent. The Controlling Party shall remove the
Subordination Agent if:

            (1) the Subordination Agent fails to comply with Section 6.9 hereof;

            (2) the Subordination Agent is adjudged bankrupt or insolvent;


                                       44
<PAGE>   48
            (3) a receiver or other public officer takes charge of the
      Subordination Agent or its property; or

            (4) the Subordination Agent otherwise becomes incapable of acting.

            If the Subordination Agent resigns or is removed or if a vacancy
exists in the office of Subordination Agent for any reason (the Subordination
Agent in such event being referred to herein as the retiring Subordination
Agent), the Controlling Party shall promptly appoint a successor Subordination
Agent.

            A successor Subordination Agent shall deliver (x) a written
acceptance of its appointment as Subordination Agent hereunder to the retiring
Subordination Agent and (y) a written assumption of its obligations hereunder
and under each Liquidity Facility to each party hereto, upon which the
resignation or removal of the retiring Subordination Agent shall become
effective, and the successor Subordination Agent shall have all the rights,
powers and duties of the Subordination Agent under this Agreement. The successor
Subordination Agent shall mail a notice of its succession to the Liquidity
Providers and the Trustees. The retiring Subordination Agent shall promptly
transfer its rights under each of the Liquidity Facilities and all of the
property held by it as Subordination Agent to the successor Subordination Agent.

            If a successor Subordination Agent does not take office within 60
days after the retiring Subordination Agent resigns or is removed, the retiring
Subordination Agent or one or more of the Trustees may petition any court of
competent jurisdiction for the appointment of a successor Subordination Agent.

            If the Subordination Agent fails to comply with Section 6.9 hereof
(to the extent applicable), one or more of the Trustees or one or more of the
Liquidity Providers may petition any court of competent jurisdiction for the
removal of the Subordination Agent and the appointment of a successor
Subordination Agent.

            Notwithstanding the foregoing, no resignation or removal of the
Subordination Agent shall be effective unless and until a successor has been
appointed. No appointment of a successor Subordination Agent shall be effective
unless and until the Rating Agencies shall have delivered a Ratings
Confirmation.


                                   ARTICLE IX

                           SUPPLEMENTS AND AMENDMENTS

            SECTION 9.1. Amendments, Waivers, etc. (a) This Agreement may not be
supplemented, amended or modified without the consent of each Trustee (acting,
except in the case of any amendment pursuant to Section 3.6(e)(v)(y) hereof,
with the consent of holders of Certificates of the related Class evidencing
interests in the related Trust aggregating not less than a majority in interest
in such Trust or as otherwise authorized pursuant to the relevant Trust
Agreement), the Subordination Agent and each Liquidity Provider; provided,
however, that this Agreement may be supplemented, amended or modified without
the consent of (x) any Trustee if such supplement, amendment or modification (i)
is in accordance with Section 9.1(c) hereof or (ii) cures an ambiguity or
inconsistency or does not materially adversely affect such Trustee or


                                       45
<PAGE>   49
the holders of the related Class of Certificates and (y) any Liquidity Provider
if such supplement, amendment or modification is in accordance with Section
9.1(c) hereof; provided further, however, that, if such supplement, amendment or
modification (A) would (x) directly or indirectly modify or supersede, or
otherwise conflict with, Section 2.2(b), Section 3.6(e), Section 3.6(f), Section
3.6(l), Section 9.1(c), the second sentence of Section 10.6 or this proviso
(collectively, the "America West Provisions") or (y) otherwise adversely affect
the interests of a potential Replacement Liquidity Provider or of America West
with respect to its ability to replace any Liquidity Facility or with respect to
its payment obligations under any Operative Agreement or (B) is made pursuant to
Section 9.1(c), then such supplement, amendment or modification shall not be
effective without the additional written consent of America West.
Notwithstanding the foregoing, without the consent of each Certificateholder and
each Liquidity Provider, no supplement, amendment or modification of this
Agreement may (i) reduce the percentage of the interest in any Trust evidenced
by the Certificates issued by such Trust necessary to consent to modify or amend
any provision of this Agreement or to waive compliance therewith or (ii), except
as provided in Section 9.1(c), modify Section 2.4, 3.2 or 3.3 hereof, relating
to the distribution of monies received by the Subordination Agent hereunder from
the Equipment Notes or pursuant to the Liquidity Facilities. Nothing contained
in this Section shall require the consent of a Trustee at any time following the
payment of Final Distributions with respect to the related Class of
Certificates. If the Replacement Liquidity Facility for any Liquidity Facility
in accordance with Section 3.6(e) hereof is to be comprised of more than one
instrument as contemplated by the definition of the term "Replacement Liquidity
Facility", then each of the parties hereto agrees to amend this Agreement to
incorporate appropriate mechanics for multiple Liquidity Facilities for an
individual Trust.

            (b) In the event that the Subordination Agent, as the registered
holder of any Equipment Notes, receives a request for its consent to any
amendment, modification, consent or waiver under such Equipment Notes, the
Indenture pursuant to which such Equipment Notes were issued, or the related
Lease, Participation Agreement or other related document, (i) if no Indenture
Default shall have occurred and be continuing with respect to such Indenture,
the Subordination Agent shall request directions with respect to each Series of
such Equipment Notes from the Trustee of the Trust which holds such Equipment
Notes and shall vote or consent in accordance with the directions of such
Trustee and (ii) if any Indenture Default (which, in the case of any Indenture
pertaining to a Leased Aircraft, has not been cured by the applicable Owner
Trustee or the applicable Owner Participant, if applicable, pursuant to Section
4.03 of such Indenture) shall have occurred and be continuing with respect to
such Indenture, the Subordination Agent will exercise its voting rights as
directed by the Controlling Party, subject to Sections 4.1 and 4.4 hereof;
provided that no such amendment, modification or waiver shall, without the
consent of each Liquidity Provider, reduce the amount of rent, supplemental rent
or stipulated loss values payable by America West under any Lease or reduce the
amount of principal or interest payable by America West under any Equipment Note
issued under any Indenture in respect of an Owned Aircraft.

            (c) If with respect to any Aircraft America West issues Class D
Certificates, this Agreement shall be amended by written agreement of America
West and the Subordination Agent to provide for the subordination of such Class
D Certificates to the Class A Certificates, the Class B Certificates and the
Class C Certificates substantially in the same manner as the Class C
Certificates are subordinated hereunder to the Class B and Class A Certificates.
No such amendment shall materially adversely affect the interests of the holders
of the Equipment Notes


                                       46
<PAGE>   50
(evidence of which shall be a certificate to such effect from an officer of
America West). The amendment to this Agreement to give effect to the issuance of
any Class D Certificates shall include, without limitation:

            (i) the trustee of the Class D Trust shall be added as a party to
      this Agreement;

            (ii) the definitions of "Cash Collateral Account," "Certificate,"
      "Class," "Equipment Notes," "Final Legal Distribution Date," "Liquidity
      Facilities," "Liquidity Provider," "LTV Ratio," "Stated Interest Rate,"
      "Trust," "Trust Agreement," "Controlling Party" shall be revised, as
      appropriate, to reflect the issuance of the Class D Certificates (and the
      subordination thereof); and

            (iii) provisions of this Agreement governing payments with respect
      to Certificates and related notices, including, without limitation,
      Sections 2.4, 3.1, 3.2, 3.3 and 3.6(e), shall be revised to provide for
      distributions on the Class D Certificates after payment of all relevant
      distributions on Class C Certificates.

            SECTION 9.2. Subordination Agent Protected. Except as provided
herein, if, in the reasonable opinion of the Subordination Agent, any document
required to be executed pursuant to the terms of Section 9.1 adversely affects
any right, duty, immunity or indemnity with respect to it under this Agreement
or any Liquidity Facility, the Subordination Agent may in its discretion decline
to execute such document.

            SECTION 9.3. Effect of Supplemental Agreements. Upon the execution
of any amendment, consent or supplement hereto pursuant to the provisions
hereof, this Agreement shall be and be deemed to be and shall be modified and
amended in accordance therewith and the respective rights, limitations of
rights, obligations, duties and immunities under this Agreement of the parties
hereto and beneficiaries hereof shall thereafter be determined, exercised and
enforced hereunder subject in all respects to such modifications and amendments,
and all the terms and conditions of any such supplemental agreement shall be and
be deemed to be and shall be part of the terms and conditions of this Agreement
for any and all purposes. In executing or accepting any supplemental agreement
permitted by this Article IX, the Subordination Agent shall be entitled to
receive at its cost, and shall be fully protected in relying upon, an opinion of
counsel stating that the execution of such supplemental agreement is authorized
or permitted by this Agreement.

            SECTION 9.4. Notice to Rating Agencies. Promptly following its
receipt of each amendment, consent, modification, supplement or waiver
contemplated by this Article IX, the Subordination Agent shall send a copy
thereof to each Rating Agency.


                                       47
<PAGE>   51
                                    ARTICLE X

                                  MISCELLANEOUS

            SECTION 10.1. Termination of Intercreditor Agreement. Following
payment of Final Distributions with respect to each Class of Certificates and
the payment in full of all Liquidity Obligations to the Liquidity Providers and
provided that there shall then be no other amounts due to the
Certificateholders, the Trustees, the Liquidity Providers and the Subordination
Agent hereunder or under the Trust Agreements, and that the commitment of the
Liquidity Providers under the Liquidity Facilities shall have expired or been
terminated, this Agreement and the trusts created hereby shall terminate and
this Agreement shall be of no further force or effect. Except as aforesaid or
otherwise provided, this Agreement and the trusts created hereby shall continue
in full force and effect in accordance with the terms hereof.

            SECTION 10.2. Intercreditor Agreement for Benefit of Trustees,
Liquidity Providers and Subordination Agent. Subject to the second sentence of
Section 10.6 and the provisions of Sections 4.4 and 9.1, nothing in this
Agreement, whether express or implied, shall be construed to give to any Person
other than the Trustees, the Liquidity Providers and the Subordination Agent any
legal or equitable right, remedy or claim under or in respect of this Agreement.

            SECTION 10.3. Notices. Unless otherwise expressly specified or
permitted by the terms hereof, all notices, requests, demands, authorizations,
directions, consents, waivers or documents provided or permitted by this
Agreement to be made, given, furnished or filed shall be in writing, mailed by
certified mail, postage prepaid, or by confirmed telecopy and

            (i)   if to the Subordination Agent, addressed to at its office at:

                  WILMINGTON TRUST COMPANY
                  Rodney Square North
                  1100 N. Market Street
                  Wilmington, DE  19890-0001
                  Attention:  Corporate Trust
                  Administration
                  Telecopy:  (302) 651-8882

            (ii)  if to any Trustee, addressed to it at its office at:

                  WILMINGTON TRUST COMPANY
                  Rodney Square North
                  1100 N. Market Street
                  Wilmington, DE  19890-0001
                  Attention:  Corporate Trust
                  Administration
                  Telecopy:  (302) 651-8882

            (iii) if to the initial Liquidity Provider, addressed to it at its
                  office at:


                                       48
<PAGE>   52
                  ABN AMRO BANK N.V.
                  135 South LaSalle Street - Suite 660
                  Chicago, Illinois  60603
                  Attention:  Vice President - Aerospace
                  Telephone:  312-904-2900
                  Telecopy:   312-606-8428

                  with a copy to:

                  ABN AMRO BANK N.V.
                  135 South LaSalle Street - Suite 625
                  Chicago, Illinois  60603
                  Attention:  Loan Administration
                  Telephone:  312-904-2961
                  Telecopy:   312-904-1288

Whenever any notice in writing is required to be given by any Trustee or
Liquidity Provider or the Subordination Agent to any of the other of them, such
notice shall be deemed given and such requirement satisfied when such notice is
received unless received outside of business hours, in which case on the next
open of business on a Business Day. Any party hereto may change the address to
which notices to such party will be sent by giving notice of such change to the
other parties to this Agreement.

            SECTION 10.4. Severability. Any provision of this Agreement which is
prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction,
be ineffective to the extent of such prohibition or unenforceability without
invalidating the remaining provisions hereof, and any such prohibition or
unenforceability in any jurisdiction shall not invalidate or render
unenforceable such provision in any other jurisdiction.

            SECTION 10.5. No Oral Modifications or Continuing Waivers. No terms
or provisions of this Agreement may be changed, waived, discharged or terminated
orally, but only by an instrument in writing signed by the party or other Person
against whom enforcement of the change, waiver, discharge or termination is
sought and any other party or other Person whose consent is required pursuant to
this Agreement and any waiver of the terms hereof shall be effective only in the
specific instance and for the specific purpose given.

            SECTION 10.6. Successors and Assigns. All covenants and agreements
contained herein shall be binding upon, and inure to the benefit of, each of the
parties hereto and the successors and assigns of each, all as herein provided.
In addition, the America West Provisions shall inure to the benefit of America
West and its successors and assigns, and (without limitation of the foregoing)
America West is hereby constituted, and agreed to be, an express third party
beneficiary of the America West Provisions. Upon the occurrence of the Transfers
contemplated by the Assignment and Assumption Agreements, the Trustee of each
Class shall (without any further act) be deemed to have transferred all of its
rights, title and interest in and to this Agreement to the trustee of the
Successor Trust of the same Class and, thereafter, the trustee of each Successor
Trust shall be deemed to be the "Trustee" of such Successor Trust with the
rights and obligations of a "Trustee" hereunder and under the other


                                       49
<PAGE>   53
Operative Agreements and each reference to a Trust of any Class herein shall be
deemed a reference to the Successor Trust of such Class.

            SECTION 10.7. Headings. The headings of the various Articles and
Sections herein and in the table of contents hereto are for convenience of
reference only and shall not define or limit any of the terms or provisions
hereof.

            SECTION 10.8. Counterpart Form. This Agreement may be executed by
the parties hereto in separate counterparts, each of which when so executed and
delivered shall be an original, but all such counterparts shall together
constitute but one and the same agreement.

            SECTION 10.9. Subordination. (a) As between the Liquidity Providers,
on the one hand, and the Trustees and the Certificateholders, on the other hand,
this Agreement shall be a subordination agreement for purposes of Section 510 of
the United States Bankruptcy Code, as amended from time to time.

            (b) Notwithstanding the provisions of this Agreement, if prior to
the payment in full to the Liquidity Providers of all Liquidity Obligations then
due and payable, any party hereto shall have received any payment or
distribution in respect of Equipment Notes or any other amount under the
Indentures or other Operative Agreements which, had the subordination provisions
of this Agreement been properly applied to such payment, distribution or other
amount, would not have been distributed to such Person, then such payment,
distribution or other amount shall be received and held in trust by such Person
and paid over or delivered to the Subordination Agent for application as
provided herein.

            (c) If any Trustee, any Liquidity Provider or the Subordination
Agent receives any payment in respect of any obligations owing hereunder (or, in
the case of the Liquidity Providers, in respect of the Liquidity Obligations),
which is subsequently invalidated, declared preferential, set aside and/or
required to be repaid to a trustee, receiver or other party, then, to the extent
of such payment, such obligations (or, in the case of the Liquidity Providers,
such Liquidity Obligations) intended to be satisfied shall be revived and
continue in full force and effect as if such payment had not been received.

            (d) The Trustees (on behalf of themselves and the holders of
Certificates), the Liquidity Providers and the Subordination Agent confirm that
the payment priorities specified in Sections 2.4, 3.2 and 3.3 shall apply in all
circumstances, notwithstanding the fact that the obligations owed to the
Trustees and the holders of Certificates are secured by certain assets and the
Liquidity Obligations may not be so secured. The Trustees expressly agree (on
behalf of themselves and the holders of Certificates) not to assert priority
over the holders of Liquidity Obligations due to their status as secured
creditors in any bankruptcy, insolvency or other legal proceeding.

            (e) Each of the Trustees (on behalf of themselves and the holders of
Certificates), the Liquidity Providers and the Subordination Agent may take any
of the following actions without impairing its rights under this Agreement:

            (i) obtain a Lien on any property to secure any amounts owing to it
      hereunder, including, in the case of the Liquidity Providers, the
      Liquidity Obligations,


                                       50
<PAGE>   54
            (ii) obtain the primary or secondary obligation of any other obligor
      with respect to any amounts owing to it hereunder, including, in the case
      of the Liquidity Providers, any of the Liquidity Obligations,

            (iii) renew, extend, increase, alter or exchange any amounts owing
      to it hereunder, including, in the case of the Liquidity Providers, any of
      the Liquidity Obligations, or release or compromise any obligation of any
      obligor with respect thereto,

            (iv) refrain from exercising any right or remedy, or delay in
      exercising such right or remedy, which it may have, or

            (v) take any other action which might discharge a subordinated party
      or a surety under applicable law;

provided, however, that the taking of any such actions by any of the Trustees,
the Liquidity Providers or the Subordination Agent shall not prejudice the
rights or adversely affect the obligations of any other party under this
Agreement.

            SECTION 10.10. Governing Law. THIS AGREEMENT SHALL IN ALL RESPECTS
BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW
YORK, INCLUDING ALL MATTERS OF CONSTRUCTION, VALIDITY AND PERFORMANCE.

            SECTION 10.11.  Submission to Jurisdiction; Waiver of Jury Trial;
Waiver of Immunity.  (a)  Each of the parties hereto hereby irrevocably and
unconditionally:

            (i) submits for itself and its property in any legal action or
      proceeding relating to this Agreement or any other Operative Agreement, or
      for recognition and enforcement of any judgment in respect hereof or
      thereof, to the nonexclusive general jurisdiction of the courts of the
      State of New York, the courts of the United States of America for the
      Southern District of New York, and the appellate courts from any thereof;

            (ii) consents that any such action or proceeding may be brought in
      such courts, and waives any objection that it may now or hereafter have to
      the venue of any such action or proceeding in any such court or that such
      action or proceeding was brought in an inconvenient court and agrees not
      to plead or claim the same;

            (iii) agrees that service of process in any such action or
      proceeding may be effected by mailing a copy thereof by registered or
      certified mail (or any substantially similar form and mail), postage
      prepaid, to each party hereto at its address set forth in Section 10.3
      hereof, or at such other address of which the other parties shall have
      been notified pursuant thereto; and

            (iv) agrees that nothing herein shall affect the right to effect
      service of process in any other manner permitted by law or shall limit the
      right to sue in any other jurisdiction.

            (b) EACH OF THE PARTIES HERETO HEREBY AGREES TO WAIVE ITS RESPECTIVE
RIGHTS TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION


                                       51
<PAGE>   55
BASED UPON OR ARISING OUT OF THIS AGREEMENT OR ANY DEALINGS BETWEEN THEM
RELATING TO THE SUBJECT MATTER OF THIS AGREEMENT AND THE RELATIONSHIP THAT IS
BEING ESTABLISHED, including, without limitation, contract claims, tort claims,
breach of duty claims and all other common law and statutory claims. Each of the
parties warrants and represents that it has reviewed this waiver with its legal
counsel, and that it knowingly and voluntarily waives its jury trial rights
following consultation with such legal counsel. THIS WAIVER IS IRREVOCABLE, AND
CANNOT BE MODIFIED EITHER ORALLY OR IN WRITING, AND THIS WAIVER SHALL APPLY TO
ANY SUBSEQUENT AMENDMENTS, RENEWALS, SUPPLEMENTS OR MODIFICATIONS TO THIS
AGREEMENT.

            (c) The Liquidity Provider hereby waives any immunity it may have
from the jurisdiction of the courts of the United States of America or of any
State and waives any immunity any of its properties located in the United States
of America may have from attachment or execution upon a judgment entered by any
such court under the United States Foreign Sovereign Immunities Act of 1976 or
any similar successor legislation.


                                       52
<PAGE>   56
            IN WITNESS WHEREOF, the parties hereto have caused this Agreement to
be duly executed by their respective officers thereunto duly authorized, as of
the day and year first above written, and acknowledge that this Agreement has
been made and delivered in the City of New York, and this Agreement has become
effective only upon such execution and delivery.

                                    WILMINGTON TRUST COMPANY,
                                       not in its individual capacity but
                                       solely as Trustee for each of the
                                       Trusts



                                    By /s/ Jill K. Morrison
                                       ----------------------------------------
                                          Name:  Jill K. Morrison
                                          Title: Administrative Account Manager

                                    ABN AMRO BANK N.V.,
                                      Chicago Branch
                                       as Class A Liquidity Provider, Class B
                                       Liquidity Provider and Class C
                                       Liquidity Provider



                                    By /s/ Claudia C. Heldring
                                       ----------------------------------------
                                          Name:  Claudia C. Heldring
                                          Title: Vice President



                                    By /s/ Carla S. Waggoner
                                       ----------------------------------------
                                          Name:  Carla S. Waggoner
                                          Title: Assistant Vice President



                                    WILMINGTON TRUST COMPANY, not in its
                                       individual capacity except as expressly
                                       set forth herein but solely as
                                       Subordination Agent and trustee



                                    By /s/ Jill K. Morrison
                                       ----------------------------------------
                                          Name:  Jill K. Morrison
                                          Title: Administrative Account Manager



                                       53

<PAGE>   1


                                                                    Exhibit 4.14




                   Exchange and Registration Rights Agreement

                           Dated as of October 6, 1998

                                      among

                          America West Airlines, Inc.,

                            Wilmington Trust Company,

                    not in its individual capacity but solely
                                as Trustee under

                              America West Airlines
                      Pass Through Trust, Series 1998-1A-O

                              America West Airlines
                      Pass Through Trust, Series 1998-1B-O

                              America West Airlines
                      Pass Through Trust, Series 1998-1C-O

                                       and

                       Morgan Stanley & Co. Incorporated,

                          Donaldson, Lufkin & Jenrette
                             Securities Corporation,

                      Merrill Lynch, Pierce, Fenner & Smith
                                  Incorporated,

                                       and

                            Salomon Smith Barney Inc.




<PAGE>   2



                   EXCHANGE AND REGISTRATION RIGHTS AGREEMENT


                  THIS EXCHANGE AND REGISTRATION RIGHTS AGREEMENT (the
"Agreement") is made and entered into as of October 6, 1998, among America West
Airlines, Inc., a Delaware corporation (the "Company"), Wilmington Trust
Company, not in its individual capacity but solely as trustee under each of the
Original Trusts (as defined below), Morgan Stanley & Co. Incorporated,
Donaldson, Lufkin & Jenrette Securities Corporation, Merrill Lynch, Pierce,
Fenner & Smith Incorporated, and Salomon Smith Barney Inc. (collectively, the
"Initial Purchasers").

                  This Agreement is made pursuant to the Purchase Agreement
dated September 24, 1998 among the Company and the Initial Purchasers (the
"Purchase Agreement"), which provides that the Trustee will issue and sell
$131,670,000 principal amount of the pass through certificates of the Class A
Trust (as defined below), $41,154,000 principal amount of the pass through
certificates of the Class B Trust (as defined below) and $17,705,000 principal
amount of the pass through certificates of the Class C Trust (as defined below)
(the Class A Trust, Class B Trust and Class C Trust together, the "Original
Trusts" and such pass through certificates of the Original Trusts, together, the
"Initial Certificates"), in each case with Escrow Receipts (as defined below)
attached thereto. On the Transfer Date (as defined below), and after
satisfaction of the conditions set forth in the Pass Through Trust Agreements
(as defined below), each of the Original Trusts will transfer and assign all of
its assets and rights to a newly-created successor trust with substantially
identical terms (together, the "Successor Trusts") and the Initial Certificates
will be deemed for all purposes of the Original Trusts and the Successor Trusts
to be certificates representing fractional undivided interests in the Successor
Trusts and their respective trust properties. In order to induce the Initial
Purchasers to enter into the Purchase Agreement, the Company has agreed to
provide to the Initial Purchasers and their direct and indirect transferees the
exchange and registration rights set forth in this Agreement. The execution and
delivery of this Agreement is a condition to the closing under the Purchase
Agreement.

                  In consideration of the foregoing, the parties hereto agree as
follows:

                  1. Definitions. The definitions set forth in this Agreement
shall apply equally to both singular and plural forms of the terms defined. As
used in this Agreement, the following capitalized defined terms shall have the
following meanings:

                  "1933 Act" shall mean the Securities Act of 1933, as amended
         from time to time.

                  "1934 Act" shall mean the Securities Exchange Act of 1934, as
         amended from time to time.

                  "Agreement" shall have the meaning set forth in the preamble
         of this Agreement.

                  "Business Day" shall mean any day on which the New York Stock
         Exchange, Inc. is open for trading and banks in The City of New York
         are open for business; references to "day" shall mean a calendar day.


<PAGE>   3

                                       2

                  "Class A Trust" shall mean the America West Airlines Pass
         Through Trust, Series 1998-1A-O.

                  "Class B Trust" shall mean the America West Airlines Pass
         Through Trust, Series 1998-1B-O.

                  "Class C Trust" shall mean the America West Airlines Pass
         Through Trust, Series 1998-1C-O.

                  "Closing Date" shall mean the Closing Date as defined in the
         Purchase Agreement.

                  "Company" shall have the meaning set forth in the preamble of
         this Agreement and shall include the Company's successors.

                  "Depositary Agreement" shall have the meaning set forth in the
         Purchase Agreement.

                  "DTC" shall mean the Depository Trust Company or any other
         depositary appointed by the Company; provided, however, that any such
         depositary must have an address in the Borough of Manhattan, in The
         City of New York.

                  "Equipment Notes" shall mean the equipment notes that are the
         property of the Trusts.

                  "Escrow Receipts" shall have the meaning set forth in the
         Purchase Agreement.

                  "Exchange Certificates" shall mean the pass through
         certificates issued under the Pass Through Trust Agreements or the
         Successor Pass Through Trust Agreements, as the case may be, and
         otherwise containing terms identical in all material respects to the
         Initial Certificates (except that, with respect to the Exchange
         Certificates of each Trust, (i) interest thereon shall accrue as set
         forth in Section 2(a) hereof, (ii) the transfer restrictions thereon
         shall be eliminated, (iii) certain provisions relating to an increase
         in the stated rate of interest thereon shall be eliminated and (iv)
         such Exchange Certificates shall initially be available only in
         book-entry form) to be offered to Holders of Initial Certificates in
         exchange for Initial Certificates pursuant to the Exchange Offer.

                  "Exchange Offer" shall mean the exchange offer by the Company
         of Exchange Certificates for Registrable Certificates pursuant to
         Section 2(a) hereof.

                  "Exchange Offer Registration" shall mean a registration under
         the 1933 Act effected pursuant to Section 2(a) hereof.

                  "Exchange Offer Registration Statement" shall mean a
         Registration Statement on Form S-4 (or, if applicable, on another
         appropriate form) filed with the SEC pursuant to 


<PAGE>   4
                                       3


         Section 2(a) of this Agreement, and all amendments and supplements to
         such Registration Statement, in each case including the Prospectus
         contained therein, all exhibits thereto and all material incorporated
         by reference therein.

                  "Holders" shall mean each of the Initial Purchasers, for so
         long as they own any Registrable Certificates, and each of their
         successors, assigns and direct and indirect transferees who become
         registered owners of Registrable Certificates.

                  "Initial Certificates" has the meaning set forth in the
         preamble of this Agreement.

                  "Initial Purchasers" shall have the meaning set forth in the
         preamble of this Agreement.

                  "Majority Holders" shall mean the Holders of a majority of the
         aggregate principal amount of outstanding Registrable Certificates;
         provided that whenever the consent or approval of Holders of a
         specified percentage of Registrable Certificates is required hereunder,
         Registrable Certificates held by the Company or any of its "affiliates"
         (as such term is defined in Rule 405 under the 1933 Act) (other than
         the Initial Purchasers or subsequent holders of Registrable
         Certificates if such subsequent holders are deemed to be affiliates
         solely by reason of their holding of such Registrable Certificates)
         shall be disregarded in determining whether such consent or approval
         was given by the Holders of such required percentage or amount.

                  "NASD" shall mean the National Association of Securities
         Dealers, Inc.

                  "Original Trusts" shall have the meaning set forth in the
         preamble of this Agreement.

                  "Participating Broker-Dealer" shall have the meaning set forth
         in Section 3(f) of this Agreement.

                  "Pass Through Trust Agreements" shall mean each of the Pass
         Through Trust Agreements relating to the Initial Certificates between
         the Company and each Trustee, as may be amended from time to time in
         accordance with the terms thereof.

                  "Person" shall mean an individual, partnership, corporation,
         trust or unincorporated organization, or a government or agency or
         political subdivision thereof.

                  "Prospectus" shall mean the prospectus included in a
         Registration Statement, including any preliminary prospectus, and any
         such prospectus as amended or supplemented by any prospectus
         supplement, including a prospectus supplement with respect to the terms
         of the offering of any portion of the Registrable Certificates covered
         by a Shelf Registration Statement, and by all other amendments and
         supplements to a prospectus, including post-effective amendments, and
         in each case including all material incorporated by reference therein.


<PAGE>   5
                                       4


                  "Purchase Agreement" shall have the meaning set forth in the
         preamble of this Agreement.

                  "Registrable Certificates" shall mean the Initial
         Certificates; provided, however, that the Initial Certificates shall
         cease to be Registrable Certificates when (i) a Shelf Registration
         Statement with respect to such Initial Certificates shall have been
         declared effective under the 1933 Act and such Initial Certificates
         shall have been disposed of pursuant to such Shelf Registration
         Statement, (ii) such Initial Certificates shall have been sold to the
         public pursuant to Rule 144 (or any similar provision then in force,
         but not Rule 144A) under the 1933 Act or may then be sold to the public
         pursuant to paragraph (k) of said Rule 144 (or any similar provision
         then in force) by Holders other than "affiliates" or former
         "affiliates" (as such term is defined in paragraph (a) of Rule 144) of
         the Company, (iii) such Initial Certificates shall have ceased to be
         outstanding or (iv) such Initial Certificates have been exchanged for
         Exchange Certificates upon consummation of the Exchange Offer.

                  "Registration Default" shall have the meaning set forth in
         Section 2(b) of this Agreement.

                  "Registration Event" shall mean the declaration of the
         effectiveness by the SEC of an Exchange Offer Registration Statement or
         a Shelf Registration Statement.

                  "Registration Expenses" shall mean any and all reasonable
         expenses incident to performance of or compliance by the Company and
         the Trustees with this Agreement, including without limitation: (i) all
         SEC, stock exchange or NASD registration and filing fees, (ii) all fees
         and expenses incurred in connection with compliance with state or other
         securities or blue sky laws and compliance with the rules of the NASD
         (including reasonable fees and disbursements of counsel for any
         underwriters or Holders in connection with state or other securities or
         blue sky qualification of any of the Exchange Certificates or
         Registrable Certificates), (iii) all expenses incurred by the Company
         in preparing or assisting in preparing, word processing, printing and
         distributing any Registration Statement, any Prospectus, any amendments
         or supplements thereto, any underwriting agreements, securities sales
         agreements and other documents relating to the performance of and
         compliance with this Agreement, (iv) all rating agency fees, (v) all
         fees and expenses incurred in connection with the listing, if any, of
         any of the Registrable Certificates on any securities exchange or
         exchanges, (vi) all fees and disbursements relating to the
         qualification of the Pass Through Trust Agreements and the Successor
         Pass Through Trust Agreements under applicable securities laws, (vii)
         the fees and disbursements of counsel for the Company and of the
         independent public accountants of the Company, including the expenses
         of any special audits or "cold comfort" letters required by or incident
         to such performance and compliance, (viii) the reasonable fees and
         expenses of the Trustees, including their counsel, and any escrow agent
         or custodian, (ix) in the case of a Shelf Registration Statement, the
         fees and disbursements of one counsel for the Holders (which counsel
         shall be selected by the Majority Holders and 


<PAGE>   6
                                       5


         which counsel may also be counsel for the Initial Purchasers) and (x)
         any reasonable fees and disbursements of the underwriters, if any, in
         connection with any Shelf Registration Statement, and the reasonable
         fees and expenses of any special experts retained by the Company in
         connection with any Registration Statement, in each case as are
         customarily required to be paid by issuers, but excluding (with respect
         to clauses (iii) through (x) above) fees of counsel to the underwriters
         (other than fees and expenses set forth in clause (ii) above) or the
         Holders and underwriting discounts and commissions and transfer taxes,
         if any relating to the sale or disposition of Registrable Certificates
         by a Holder.

                  "Registration Statement" shall mean any registration statement
         of the Company which covers any of the Exchange Certificates or
         Registrable Certificates pursuant to the provisions of this Agreement,
         and all amendments and supplements to any such Registration Statement,
         including post-effective amendments, in each case including the
         Prospectus contained therein, all exhibits thereto and all material
         incorporated by reference therein.

                  "SEC" shall mean the Securities and Exchange Commission, as
         from time to time constituted or created under the United States
         Securities Exchange Act of 1934, as amended, or, if at any time after
         the execution of this instrument such Commission is not existing and
         performing the duties now assigned to it under the TIA, then the body
         performing such duties on such date.

                  "Shelf Registration" shall mean a registration under the 1933
         Act effected pursuant to Section 2(b) hereof.

                  "Shelf Registration Statement" shall mean a "shelf"
         registration statement of the Company pursuant to the provisions of
         Section 2(b) of this Agreement which covers some or all of the
         Registrable Certificates (but no other securities unless approved by
         the Holders whose Registrable Certificates are covered by such Shelf
         Registration Statement) on an appropriate form under Rule 415 under the
         1933 Act, or any similar rule that may be adopted by the SEC, and all
         amendments and supplements to such registration statement, including
         post-effective amendments, in each case including the Prospectus
         contained therein, all exhibits thereto and all material incorporated
         by reference therein.

                  "Staff" shall mean the Staff of the Division of Corporation
         Finance of the SEC.

                  "Successor Pass Through Trust Agreements" shall mean each of
         the Successor Pass Through Trust Agreements entered into on the date
         hereof between the Company and each Trustee forming the Successor
         Trusts, as may be amended from time to time in accordance with the
         terms thereof.

                  "Successor Trusts" shall have the meaning set forth in the
         preamble of this Agreement.


<PAGE>   7
                                       6


                  "TIA" shall have the meaning set forth in Section 3(l) of this
         Agreement.

                  "Transfer Date" shall have the meaning set forth in the
         Purchase Agreement.

                  "Trustees" shall mean the trustees under the Pass Through
         Trust Agreements or the Successor Pass Through Trust Agreements, as the
         case may be.

                  "Trusts" shall mean the Class A Trust, the Class B Trust, the
         Class C Trust and the Class D Trust, or the Successor Trusts, as the
         case may be.

                  2. Registration under the 1933 Act. (a) Exchange Offer
Registration. To the extent not prohibited by any applicable law or applicable
interpretation of the Staff, the Company shall use its best efforts (A) to file
with the SEC within 120 days after the Closing Date an Exchange Offer
Registration Statement covering the offer by the Company to the Holders to
exchange all of the Registrable Certificates for Exchange Certificates, (B) to
cause such Exchange Offer Registration Statement to be declared effective by the
SEC within 180 days after the Closing Date, (C) to cause such Registration
Statement to remain effective until the closing of the Exchange Offer and (D) to
consummate the Exchange Offer within 210 days after the Closing Date. Upon the
effectiveness of the Exchange Offer Registration Statement, the Company shall
promptly commence the Exchange Offer, it being the objective of such Exchange
Offer to enable each Holder (other than Participating Broker-Dealers) eligible
and electing to exchange Registrable Certificates for Exchange Certificates
(assuming that such Holder is not an affiliate of the Company within the meaning
of Rule 405 under the 1933 Act, acquires the Exchange Certificates in the
ordinary course of such Holder's business and has no arrangements or
understandings with any person to participate in the Exchange Offer for the
purpose of distributing the Exchange Certificates) to trade such Exchange
Certificates from and after their receipt without any limitations or
restrictions under the 1933 Act and without material restrictions under the
securities laws of a substantial proportion of the several states of the United
States.

                  In connection with the Exchange Offer, the Company shall or
shall direct the Trustees to and the Trustee shall:

                  (i) mail to each Holder a copy of the Prospectus forming part
         of the Exchange Offer Registration Statement, together with an
         appropriate letter of transmittal and related documents;

                  (ii) keep the Exchange Offer open for not less than 30 days
         after the date notice thereof is mailed to the Holders (or longer if
         required by applicable law);

                  (iii) use the services of DTC for the Exchange Offer with
         respect to Initial Certificates evidenced by global certificates;

                  (iv) permit Holders to withdraw tendered Registrable
         Certificates at any time prior to the close of business, New York City
         time, on the last Business Day on which the 


<PAGE>   8
                                       7


         Exchange Offer shall remain open, by delivering to the institution
         specified in the notice, a telegram, telex, facsimile transmission or
         letter setting forth the name of such Holder, the principal amount of
         Registrable Certificates delivered for exchange, and a statement that
         such Holder is withdrawing its election to have such Registrable
         Certificates exchanged;

                  (v) use its best efforts to ensure that (i) any Exchange Offer
         Registration Statement and any amendment thereto and any Prospectus
         forming part thereof and any supplement thereto complies in all
         material respects with the 1933 Act and the rules and regulations
         thereunder, (ii) any Exchange Offer Registration Statement and any
         amendment thereto does not, when it becomes effective, contain an
         untrue statement of a material fact or omit to state a material fact
         required to be stated therein or necessary to make the statements
         therein not misleading and (iii) any Prospectus forming part of any
         Exchange Offer Registration Statement, and any supplement to such
         Prospectus (as amended or supplemented from time to time), does not,
         prior to the consummation of the Exchange Offer, include an untrue
         statement of a material fact or omit to state a material fact necessary
         in order to make the statements, in light of the circumstances under
         which they were made, not misleading; and

                  (vi) otherwise comply in all respects with all applicable laws
         relating to the Exchange Offer.

                  As soon as practicable after the close of the Exchange Offer,
the Company shall or shall direct the Trustees to and the Trustees shall:

                  (i) accept for exchange Registrable Certificates duly tendered
         and not validly withdrawn pursuant to the Exchange Offer in accordance
         with the terms of the Exchange Offer Registration Statement and the
         letter of transmittal which is an exhibit thereto;

                  (ii) cancel or cause to be canceled all Registrable
         Certificates so accepted for exchange by the Company; and

                  (iii) promptly cause to be authenticated and delivered
         Exchange Certificates to each Holder of Registrable Certificates equal
         in amount to the Registrable Certificates of such Holder so accepted
         for exchange.

                  Interest on each Exchange Certificate will accrue from the
last date on which interest was paid on the Registrable Certificates surrendered
in exchange therefor or, if no interest has been paid on the Registrable
Certificates, from the Closing Date. The Exchange Offer shall not be subject to
any conditions, other than that the Exchange Offer, or the making of any
exchange by a Holder, does not violate applicable law or any applicable
interpretation of the Staff. Each Holder of Registrable Certificates (other than
Participating Broker-Dealers) who wishes to exchange such Registrable
Certificates for Exchange Certificates in the Exchange Offer shall represent
that (i) it is not an "affiliate" of the Company or the Trustee within the
meaning of Rule 405 under the 1933 Act, (ii) any Exchange Certificates to be
received by it were 


<PAGE>   9
                                       8


acquired in the ordinary course of business and (iii) it has no arrangement with
any Person to participate in the distribution (within the meaning of the 1933
Act) of the Exchange Certificates.

                  (b) Shelf Registration. (i) If, because of any change in law
or applicable interpretations thereof by the Staff, the Company is not permitted
to effect the Exchange Offer as contemplated by Section 2(a) hereof, or (ii) if
for any other reason the Exchange Offer is not consummated within 210 days after
the Closing Date (a "Registration Default"), or (iii) if any Holder (other than
a Purchaser) is not eligible to participate in the Exchange Offer or (iv) upon
the request of any Purchaser (with respect to any Registrable Certificates which
it acquired directly from the Company) following the consummation of the
Exchange Offer if such Purchaser shall hold Registrable Certificates which it
acquired directly from the Company and if such Purchaser is not permitted, in
the opinion of counsel to such Purchaser, pursuant to applicable law or
applicable interpretation of the Staff to participate in the Exchange Offer, the
Company shall, at its cost:

                  (A) as promptly as practicable, file with the SEC a Shelf
         Registration Statement relating to the offer and sale of the
         Registrable Certificates by the Holders from time to time in accordance
         with the methods of distribution elected by the Majority Holders of
         such Registrable Certificates and set forth in such Shelf Registration
         Statement, and use its best efforts to cause such Shelf Registration
         Statement to be declared effective by the SEC by the 180th day after
         the Closing Date in the event that the Company is not permitted to
         effect the Exchange Offer as contemplated by Section 2(a) hereof (or
         promptly if the Exchange Offer is not consummated within 210 days after
         the Closing Date or in the event of a request by any Holder pursuant to
         clause (iii) above or any Purchaser pursuant to clause (iv) above). In
         the event that the Company is required to file a Shelf Registration
         Statement upon the request of any Holder (other than a Purchaser) not
         eligible to participate in the Exchange Offer pursuant to clause (iii)
         above or upon the request of any Purchaser pursuant to clause (iv)
         above, the Company shall file and use its best efforts to have declared
         effective by the SEC both an Exchange Offer Registration Statement
         pursuant to Section 2(a) with respect to all Registrable Certificates
         and a Shelf Registration Statement (which may be a combined
         Registration Statement with the Exchange Offer Registration Statement)
         with respect to offers and sales of Registrable Certificates held by
         such Holder or such Purchaser after completion of the Exchange Offer.
         If the Company files a Shelf Registration Statement pursuant to Section
         2(b)(i) or (ii) hereof, the Company will no longer be required to
         effect the Exchange Offer;

                  (B) use its best efforts to keep the Shelf Registration
         Statement continuously effective, in order to permit the Prospectus
         forming part thereof to be usable by Holders, until the end of the
         period referred to in Rule 144(k) or any successor provision thereof
         (or one year from the Closing Date if such Shelf Registration Statement
         is filed upon the request of any Purchaser pursuant to clause (iv)
         above) or such shorter period as shall end when all of the Registrable
         Certificates covered by the Shelf Registration Statement have been sold
         pursuant to the Shelf Registration Statement or cease to be
         outstanding; and
<PAGE>   10
                                       9


                  (C) notwithstanding any other provisions hereof, use its best
         efforts to ensure that (i) any Shelf Registration Statement and any
         amendment thereto and any Prospectus forming part thereof and any
         supplement thereto complies in all material respects with the 1933 Act
         and the rules and regulations thereunder, (ii) any Shelf Registration
         Statement and any amendment thereto (in either case, other than with
         respect to information included therein in reliance upon or in
         conformity with information furnished to the Company by or on behalf of
         a Holder specifically for use therein (the "Holders' Information"))
         does not, when it becomes effective, contain an untrue statement of a
         material fact or omit to state a material fact required to be stated
         therein or necessary to make the statements therein not misleading and
         (iii) during the period in which the Shelf Registration Statement is
         effective any Prospectus forming part of any Shelf Registration
         Statement, and any supplement to such Prospectus (as amended or
         supplemented from time to time) (in any case, other than with respect
         to Holders' Information), does not include an untrue statement of a
         material fact or omit to state a material fact necessary in order to
         make the statements, in light of the circumstances under which they
         were made, not misleading.

                  The Company further agrees, if necessary, to supplement or
amend the Shelf Registration Statement if reasonably requested by the Majority
Holders with respect to Holders' Information and otherwise as required by
Section 3(b) below, to use all reasonable efforts to cause any such amendment to
become effective and such Shelf Registration Statement to become usable as soon
as practicable thereafter and to furnish to the Holders of Registrable
Certificates included in the Shelf Registration Statement copies of any such
supplement or amendment promptly after its being used or filed with the SEC.

                  The Company shall be allowed a period of five days, beginning
on the first day a Registration Default occurs, to cure such Registration
Default before the Company will be required to comply with the requirements of
Section 2(b).

                  (c) Expenses. The Company shall pay all Registration Expenses
in connection with the registration pursuant to Section 2(a) or 2(b) and, in the
case of any Shelf Registration Statement, will reimburse the Holders or Initial
Purchasers for the reasonable fees and disbursements of one firm or counsel
designated in writing by the Majority Holders to act as counsel for the Holders
of the Registrable Certificates in connection therewith. Each Holder shall pay
all expenses of its counsel, other than as set forth in the preceding sentence,
underwriting discounts and commissions and transfer taxes, if any, relating to
the sale or disposition of such Holder's Registrable Certificates pursuant to
the Shelf Registration Statement.

                  (d) Effective Registration Statement. (i) The Company will be
deemed not to have used its best efforts to cause the Exchange Offer
Registration Statement or the Shelf Registration Statement, as the case may be,
to become, or to remain, effective during the requisite period if the Company
voluntarily takes any action that would result in any such Registration
Statement not being declared effective or in the Holders of Registrable
Certificates covered thereby not being able to exchange or offer and sell such
Registrable Certificates during 


<PAGE>   11
                                       10


that period unless (A) such action is required by applicable law or (B) such
action is taken by the Company in good faith and for valid business reasons (not
including avoidance of the Company's obligations hereunder), including, without
limitation, the acquisition or divestiture of assets, so long as the Company
promptly complies with the requirements of Section 3(j) hereof, if applicable.

                  (ii) An Exchange Offer Registration Statement pursuant to
Section 2(a) hereof or a Shelf Registration Statement pursuant to Section 2(b)
hereof will not be deemed to have become effective unless it has been declared
effective by the SEC; provided, however, that if, after it has been declared
effective, the offering of Registrable Certificates pursuant to a Registration
Statement is interfered with by any stop order, injunction or other order or
requirement of the SEC or any other governmental agency or court, such
Registration Statement will be deemed not to have been effective during the
period of such interference, until the offering of Registrable Certificates
pursuant to such Registration Statement may legally resume.

                  (e) Increase in Interest Rate. In the event that no
Registration Event has occurred on or prior to the 210th day after the Closing
Date, the interest rate per annum payable in respect of the Initial Certificates
shall be increased by 0.50%, effective from and including such 210th day, to but
excluding the earlier of (i) the date on which a Registration Event occurs and
(ii) the date on which there cease to be any Registrable Certificates, which
additional interest shall be paid through a combination of an increase in the
interest rate per annum borne by the Equipment Notes of 0.50% and, if
applicable, an increase in the interest rate per annum payable on the Deposits
of 0.50% pursuant to the Depositary Agreements. In the event that the Shelf
Registration Statement ceases to be effective at any time during the period
specified by Section 2(b)(B) hereof for more than 60 days, whether or not
consecutive, during any 12-month period, the interest rate payable in respect of
the Initial Certificates shall be increased by 0.50% per annum from the 61st day
of the applicable 12-month period such Shelf Registration Statement ceases to be
effective until such time as the Shelf Registration Statement again becomes
effective (or, if earlier, the end of the period specified by Section 2(b)(B)
hereof), which additional interest shall be paid through a combination of an
increase in the interest rate per annum borne by the Equipment Notes of 0.50%
and, if applicable, an increase in the interest rate per annum payable on the
Deposits of 0.50% pursuant to the Depositary Agreements.

                  (f) Specific Performance. Without limiting the remedies
available to the Initial Purchasers and the Holders, the Company acknowledges
that any failure by the Company to comply with its obligations under Section
2(a) and Section 2(b) hereof may result in material irreparable injury to the
Initial Purchasers or the Holders for which there is no adequate remedy at law,
that it will not be possible to measure damages for such injuries precisely and
that, in the event of any such failure, each Initial Purchaser or any Holder may
obtain such relief as may be required to specifically enforce the Company's
obligations under Section 2(a) and Section 2(b) hereof.

                  3. Registration Procedures. In connection with the obligations
of the Company with respect to the Registration Statements pursuant to Sections
2(a) and 2(b) hereof, the Company shall:


<PAGE>   12
                                       11


                  (a) prepare and file with the SEC a Registration Statement,
         within the time period specified in Section 2, on the appropriate form
         under the 1933 Act, which form (i) shall be selected by the Company,
         (ii) shall, in the case of a Shelf Registration, be available for the
         sale of the Registrable Certificates by the selling Holders thereof and
         (iii) shall comply as to form in all material respects with the
         requirements of the applicable form;

                  (b) prepare and file with the SEC such amendments and
         post-effective amendments to each Registration Statement as may be
         necessary under applicable law to keep such Registration Statement
         effective for the applicable period; cause each Prospectus to be
         supplemented by any required prospectus supplement, and as so
         supplemented to be filed pursuant to Rule 424 under the 1933 Act;

                  (c) in the case of a Shelf Registration, (i) notify each
         Holder of Registrable Certificates when a Shelf Registration Statement
         with respect to the Registrable Certificates has been filed and advise
         such Holders that the distribution of Registrable Certificates will be
         made in accordance with the method elected by the Majority Holders;
         (ii) furnish to each Holder of Registrable Certificates included within
         the coverage of the Shelf Registration Statement at least one copy of
         such Shelf Registration Statement and any post-effective amendment
         thereto, including financial statements and schedules, and, if the
         Holder so requests in writing, all reports, other documents and
         exhibits filed with the SEC (including those incorporated by reference)
         at the expense of the Company, (iii) furnish to each Holder of
         Registrable Certificates included within the coverage of the Shelf
         Registration Statement, to counsel for the Holders and to each
         underwriter of an underwritten offering of Registrable Certificates, if
         any, without charge, as many copies of each Prospectus, including each
         preliminary Prospectus, and any amendment or supplement thereto as such
         Holder or underwriter may reasonably request in order to facilitate the
         public sale or other disposition of the Registrable Certificates; and
         (iv) subject to the last paragraph of Section 3, consent to the use of
         the Prospectus or any amendment or supplement thereto by each of the
         selling Holders of Registrable Certificates included in the Shelf
         Registration Statement in connection with the offering and sale of the
         Registrable Certificates covered by the Prospectus or any amendment or
         supplement thereto;

                  (d) use its best efforts to register or qualify the
         Registrable Certificates or cooperate with the Holders of Registrable
         Certificates and their counsel in the registration or qualification of
         such Registrable Certificates under all applicable state securities or
         "blue sky" laws of such jurisdictions as any Holder of Registrable
         Certificates covered by a Registration Statement and each underwriter
         of an underwritten offering of Registrable Certificates shall
         reasonably request in writing, to cooperate with the Holders in
         connection with any filings required to be made with the NASD, and do
         any and all other acts and things which may be reasonably necessary or
         advisable to enable such Holders to consummate the disposition in each
         such jurisdiction of such Registrable Certificates owned by such
         Holders; provided, however, that in no event shall the Company be


<PAGE>   13
                                       12


         required to (i) qualify as a foreign corporation or as a dealer in
         securities in any jurisdiction where it would not otherwise be required
         to qualify but for this Section 3(d) or (ii) take any action which
         would subject it to general service of process or taxation in any such
         jurisdiction if it is not then so subject;

                  (e) in the case of a Shelf Registration or in the case of an
         Exchange Registration if the Company has received from a Participating
         Broker-Dealer the notice specified in Section 3(f)(ii), notify each
         Holder of Registrable Certificates included in such Shelf Registration
         and such Participating Broker-Dealer promptly and, if requested by such
         Holder, Participating Broker-Dealer or their counsel, confirm such
         advice in writing promptly (i) when a Registration Statement has become
         effective and when any post-effective amendments and supplements
         thereto become effective, (ii) of any request by the SEC or any state
         securities authority for post-effective amendments and supplements to a
         Registration Statement and Prospectus or for additional information
         after the Registration Statement has become effective, (iii) of the
         issuance by the SEC or any state securities authority of any stop order
         suspending the effectiveness of a Registration Statement or the
         initiation of any proceedings for that purpose, (iv) in the case of a
         Shelf Registration at the closing of any sale of Registrable
         Certificates if, between the effective date of a Shelf Registration
         Statement and such closing, the representations and warranties of the
         Company contained in any underwriting agreement, securities sales
         agreement or other similar agreement, if any, relating to such offering
         cease to be true and correct in all material respects, (v) of the
         receipt by the Company of any notification with respect to the
         suspension of the qualification of the Registrable Certificates for
         sale in any jurisdiction or the initiation or threatening of any
         proceeding for such purpose, (vi) of the happening of any material
         event or the discovery of any material facts during the period a
         Registration Statement is effective which makes any statement made in
         such Registration Statement or the related Prospectus untrue or which
         requires the making of any changes in such Registration Statement or
         Prospectus in order to make the statements therein (in the case of the
         Prospectus in light of the circumstances under which they were made)
         not misleading and (vii) of any determination by the Company that a
         post-effective amendment to a Registration Statement would be
         appropriate;

                  (f) (A) in the case of the Exchange Offer, (i) include in the
                  Exchange Offer Registration Statement a "Plan of Distribution"
                  section covering the use of the Prospectus included in the
                  Exchange Offer Registration Statement by broker-dealers who
                  have exchanged their Registrable Certificates for Exchange
                  Certificates for the resale of such Exchange Certificates,
                  (ii) furnish to each broker-dealer who has delivered to the
                  Company a notice that they will be utilizing the Prospectus
                  contained in the Exchange Offer Registration Statement to sell
                  Exchange Certificates and is required to deliver a Prospectus
                  and who agrees to be bound by the applicable terms of this
                  Agreement, without charge, as many copies of each Prospectus
                  included in the Exchange Offer Registration Statement,
                  including any preliminary prospectus, and any amendment or
                  supplement thereto, as such broker-dealer may reasonably
                  request, (iii) include in 


<PAGE>   14
                                       13


                  the Exchange Offer Registration Statement a statement that any
                  broker-dealer who holds Registrable Certificates acquired for
                  its own account as a result of market-making activities or
                  other trading activities (a "Participating Broker-Dealer"),
                  and who receives Exchange Certificates for Registrable
                  Certificates pursuant to the Exchange Offer, may be a
                  statutory underwriter and must deliver a prospectus meeting
                  the requirements of the 1933 Act in connection with any resale
                  of such Exchange Certificates, (iv) subject to the last
                  paragraph of Section 3, hereby consent to the use of the
                  Prospectus forming part of the Exchange Offer Registration
                  Statement or any amendment or supplement thereto, by any
                  broker-dealer who has delivered the notice specified in clause
                  (ii) above in connection with the sale or transfer of the
                  Exchange Certificates covered by the Prospectus or any
                  amendment or supplement thereto, and (v) include in the
                  transmittal letter or similar documentation to be executed by
                  an exchange offeree in order to participate in the Exchange
                  Offer the following provision:

                           "If the undersigned is not a broker-dealer, the
                           undersigned represents that it is not engaged in, and
                           does not intend to engage in, a distribution of
                           Exchange Certificates. If the undersigned is a
                           broker-dealer that will receive Exchange Certificates
                           for its own account in exchange for Registrable
                           Certificates, it represents that the Registrable
                           Certificates to be exchanged for Exchange
                           Certificates were acquired by it as a result of
                           market-making activities or other trading activities
                           and acknowledges that it will deliver a prospectus
                           meeting the requirements of the 1933 Act in
                           connection with any resale of such Exchange
                           Certificates pursuant to the Exchange Offer; however,
                           by so acknowledging and by delivering a prospectus,
                           the undersigned will not be deemed to admit that it
                           is an "underwriter" within the meaning of the 1933
                           Act";

                           (B) to the extent any Participating Broker-Dealer
                  participates in the Exchange Offer, use its best efforts to
                  cause to be delivered at the request of an entity representing
                  the Participating Broker-Dealers (which entity shall be Morgan
                  Stanley & Co. Incorporated, unless it elects not to act as
                  such representative) only one, if any, "cold comfort" letter
                  with respect to the Prospectus in the form existing on the
                  last date for which exchanges are accepted pursuant to the
                  Exchange Offer and with respect to each subsequent amendment
                  or supplement, if any, effected during the period specified in
                  clause (C) below;

                           (C) to the extent any Participating Broker-Dealer
                  participates in the Exchange Offer, use its best efforts to
                  maintain the effectiveness of the Exchange Offer Registration
                  Statement for such period of time as any Participating
                  Broker-Dealer must comply with the prospectus delivery
                  requirements of the 1933 Act; provided, however, that such
                  period shall not exceed the 180-day period specified in clause
                  (D) below; and


<PAGE>   15
                                       14


                           (D) not be required to amend or supplement the
                  Prospectus contained in the Exchange Offer Registration
                  Statement as would otherwise be contemplated by Section 3(b),
                  or take any other action as a result of this Section 3(f), for
                  a period exceeding 180 days after the last date for which
                  exchanges are accepted pursuant to the Exchange Offer (as such
                  period may be extended by the Company) and Participating
                  Broker-Dealers shall not be authorized by the Company to, and
                  shall not, deliver such Prospectus after such period in
                  connection with resales contemplated by this Section 3;

                  (g) (A) in the case of an Exchange Offer, furnish counsel for
         the Initial Purchasers and (B) in the case of a Shelf Registration,
         furnish counsel for the Holders of Registrable Certificates copies of
         any request by the SEC or any state securities authority for amendments
         or supplements to a Registration Statement and Prospectus or for
         additional information;

                  (h) make every reasonable effort to obtain the withdrawal of
         any order suspending the effectiveness of a Registration Statement as
         soon as practicable;

                  (i) unless any Registrable Certificates are in book entry form
         only, in the case of a Shelf Registration, cause the Trustees to
         cooperate with the selling Holders of Registrable Certificates to
         facilitate the timely preparation and delivery of certificates
         representing Registrable Certificates to be sold free from any
         restrictive legends; and cause such Registrable Certificates to be in
         such denominations (consistent with the provisions of the Pass Through
         Trust Agreements or the Successor Pass Through Trust Agreements, as the
         case may be) and registered in such names as the selling Holders or the
         underwriters, if any, may reasonably request at least two Business Days
         prior to the closing of any sale of Registrable Certificates;

                  (j) in the case of a Shelf Registration, upon the occurrence
         of any event or the discovery of any facts, each as contemplated by
         Sections 2(d)(i)(B) or 3(e)(ii)-(vi) hereof, use its best efforts to
         prepare a post-effective amendment to a Registration Statement or an
         amendment or supplement to the related Prospectus or file any other
         required document so that, as thereafter delivered to the Initial
         Purchasers of the Registrable Certificates, such Prospectus will not
         contain at the time of such delivery any untrue statement of a material
         fact or omit to state a material fact necessary to make the statements
         therein, in light of the circumstances under which they were made, not
         misleading. The Company agrees to notify each Holder to suspend use of
         the Prospectus as promptly as practicable after the occurrence of such
         an event, and each Holder hereby agrees to suspend use of the
         Prospectus as promptly as practicable upon receipt of such notice until
         the Company has amended or supplemented the Prospectus to correct such
         misstatement or omission or until notified that use of the Prospectus
         may be resumed, provided that the Company shall use all reasonable
         efforts to cause such suspension not to last more than 30 days per
         occurrence or more than 60 days in aggregate in a calendar year. At
         such time as such public disclosure is otherwise made or the Company


<PAGE>   16
                                       15


         determines that such disclosure is not necessary, in each case to
         correct any misstatement of a material fact or to include any omitted
         material fact, the Company agrees promptly to notify each Holder of
         such determination and to furnish each Holder such numbers of copies of
         the Prospectus, as amended or supplemented, as such Holder may
         reasonably request;

                  (k) obtain a CUSIP number for all Exchange Certificates, or
         Registrable Certificates, as the case may be, of each Trust not later
         than the effective date of an Exchange Offer Registration Statement or
         Shelf Registration Statement, as the case may be, and provide the
         Trustees with certificates evidencing the Exchange Certificates or the
         Registrable Certificates, as the case may be, held in book entry form,
         in a form eligible for deposit with DTC;

                  (l) (i) cause the Pass Through Trust Agreements or Successor
         Pass Through Trust Agreements, as the case may be, to be qualified
         under the Trust Indenture Act of 1939, as amended (the "TIA"), in
         connection with the registration of the Exchange Certificates, or
         Registrable Certificates, as the case may be, (ii) cooperate with the
         Trustees and the Holders to effect such changes to the Pass Through
         Trust Agreements or Successor Pass Through Trust Agreements as may be
         required for the Pass Through Trust Agreements or Successor Pass
         Through Trust Agreements, as the case may be, to be so qualified in
         accordance with the terms of the TIA and (iii) execute, and use its
         best efforts to cause the Trustees to execute, all documents as may be
         required to effect such changes, and all other forms and documents
         required to be filed with the SEC to enable the Pass Through Trust
         Agreements or Successor Pass Through Trust Agreements, as the case may
         be, to be so qualified in a timely manner;

                  (m) in the case of a Shelf Registration, enter into such
         customary agreements (including underwriting agreements in customary
         form) and take all other customary and appropriate actions (including
         those reasonably requested by the Holders of a majority in principal
         amount of Registrable Certificates being sold) in order to expedite or
         facilitate the disposition of such Registrable Certificates and in such
         connection whether or not an underwriting agreement is entered into and
         whether or not the registration is an underwritten registration:

                           (i) make such representations and warranties to the
                  Holders of such Registrable Certificates and the underwriters,
                  if any, in form, substance and scope as are customarily made
                  by the Company to underwriters in similar underwritten
                  offerings as may be reasonably requested by them;

                           (ii) obtain opinions of counsel to the Company (who
                  may be the general counsel of the Company) and updates thereof
                  (which counsel and opinions (in form, scope and substance)
                  shall be reasonably satisfactory to the managing underwriters,
                  if any, or if there are no such managing underwriters, to the
                  Holders of a majority in principal amount of the Registrable
                  Certificates being sold) addressed to each selling Holder and
                  the underwriters, if any, covering the matters 


<PAGE>   17
                                       16


                  customarily covered in opinions requested in sales of
                  securities or underwritten offerings;

                           (iii) obtain a "cold comfort" letter and updates
                  thereof from the Company's independent certified public
                  accountants addressed to the underwriters, if any, such letter
                  to be in customary form and covering such matters of the type
                  customarily covered in "cold comfort" letters in connection
                  with similar underwritten offerings as the managing
                  underwriters shall reasonably request;

                           (iv) enter into a securities sales agreement with the
                  Holders and an agent of the Holders providing for, among other
                  things, the appointment of such agent for the selling Holders
                  for the purpose of soliciting purchases of Registrable
                  Certificates, which agreement shall be in form, substance and
                  scope customary for similar offerings;

                           (v) if an underwriting agreement is entered into,
                  cause the same to set forth indemnification provisions and
                  procedures substantially equivalent to the indemnification
                  provisions and procedures set forth in Section 5 hereof (or
                  such other provisions and procedures acceptable to Holders of
                  a majority in principal amount of Registrable Certificates
                  being sold and the managing underwriters) with respect to all
                  parties to be indemnified pursuant to said Section; and

                           (vi) deliver such other documents and certificates as
                  may be reasonably requested by Holders of a majority in
                  principal amount of Registrable Certificates being sold, and
                  as are customarily delivered in similar offerings.

         The above shall be done at (i) the effectiveness of such Registration
         Statement (and, if appropriate, each post-effective amendment thereto)
         if appropriate in connection with any particular disposition of
         Registrable Certificates and (ii) each closing under any underwriting
         or similar agreement as and to the extent required thereunder. In the
         case of any underwritten offering, the Company shall provide written
         notice to the Holders of all Registrable Certificates of such
         underwritten offering at least 30 days prior to the filing of the
         prospectus supplement in connection with such underwritten offering.
         Such notice shall (x) offer each such Holder the right to participate
         in such underwritten offering, (y) specify a date, which shall be no
         earlier than 10 days following the date of such notice, by which such
         Holder must inform the Company of its intent to participate in such
         underwritten offering and (z) include the instructions such Holder must
         follow in order to participate in such underwritten offering;

                  (n) in the case of a Shelf Registration, make available for
         inspection by representatives of the Holders of the Registrable
         Certificates and any underwriters participating in any disposition
         pursuant to a Shelf Registration Statement and any counsel or
         accountant retained by such Holders or underwriters, all financial and
         other records, pertinent corporate documents and properties of the
         Company reasonably 


<PAGE>   18
                                       17


         requested by it, and cause the respective officers, directors,
         employees, and any other agents of the Company to make reasonably
         available all relevant information reasonably requested by any such
         representative, underwriter, counsel or accountant in connection with a
         Registration Statement, in each case as is customary for similar due
         diligence examinations; provided, however, that any information that is
         designated in writing by the Company, in good faith, as confidential at
         the time of delivery of such information shall be kept confidential by
         such representatives, underwriters, counsel or accountant, unless such
         disclosure is made in connection with a court proceeding or required by
         law, or such information becomes available to the public generally or
         through a third party without an accompanying obligation of
         confidentiality; and provided further that the foregoing inspection and
         information gathering shall, to the extent reasonably possible, be
         coordinated on behalf of the Holders and the other parties entitled
         thereto by one counsel designated by and on behalf of such Holders and
         other parties; and provided further that each person performing such
         inspection and information gathering will be required to execute a
         confidentiality agreement containing customary terms and provisions and
         to agree that upon learning that disclosure of such information is
         sought in connection with a court proceeding or required by law, it
         will give notice to the Company and allow the Company at its expense to
         undertake appropriate action to prevent disclosure of such confidential
         information;

                  (o) (i) a reasonable time prior to the filing of any Exchange
         Offer Registration Statement, any Prospectus forming a part thereof,
         any amendment to an Exchange Offer Registration Statement or amendment
         or supplement to a Prospectus, provide copies of such document to the
         Initial Purchasers, and use its best efforts to reflect in any such
         document when filed such comments as any of the Initial Purchasers or
         their counsel may reasonably request; (ii) in the case of a Shelf
         Registration, a reasonable time prior to filing any Shelf Registration
         Statement, any Prospectus forming a part thereof, any amendment to such
         Shelf Registration Statement or amendment or supplement to such
         Prospectus (unless such supplement is being filed in response to a
         request by a Holder to amend any Holder's Information with respect to
         such Holder), provide copies of such document to the Holders of
         Registrable Certificates participating in a disposition thereunder, to
         the Initial Purchasers, to counsel on behalf of the Holders and to the
         underwriter or underwriters of an underwritten offering of Registrable
         Certificates, if any, and use its best efforts to reflect such comments
         in any such document when filed as such Holders of Registrable
         Certificates, their counsel and any underwriter may reasonably request;
         and (iii) cause the representatives of the Company to be available for
         discussion of such document as shall be reasonably requested by such
         Holders of Registrable Certificates, the Initial Purchasers on behalf
         of such Holders or any underwriter and shall not at any time make any
         filing of any such document of which such Holders, the Initial
         Purchasers on behalf of such Holders, their counsel or any underwriter
         shall not have previously been advised and furnished a copy or to which
         such Holders, the Initial Purchasers on behalf of such Holders, their
         counsel or any underwriter shall reasonably object;


<PAGE>   19
                                       18


                  (p) use its best efforts to cause the Exchange Certificates or
         Registrable Certificates, as the case may be, to be rated with two
         nationally recognized statistical rating organizations (as such term is
         defined in Rule 436(g)(12) under the 1933 Act);

                  (q) in the case of a Shelf Registration, use its best efforts
         to cause all Registrable Certificates to be listed on any securities
         exchange or any automated quotation system on which similar securities
         issued by the Company are then listed if requested by the Majority
         Holders, to the extent such Registrable Certificates satisfy applicable
         listing requirements; and

                  (r) otherwise use its best efforts to comply with all
         applicable rules and regulations of the SEC and make generally
         available to its security holders, as soon as reasonably practicable
         after the effective date of a Registration Statement, an earnings
         statement which shall satisfy the provisions of Section 11(a) of the
         1933 Act and Rule 158 thereunder.

                  In the case of a Shelf Registration Statement, the Company may
(as a condition to such Holder's participation in the Shelf Registration)
require each Holder of Registrable Certificates to agree to be bound by the
applicable terms of this Agreement and to furnish to the Company such
information regarding such Holder and the proposed distribution by such Holder
of such Registrable Certificates as the Company may from time to time reasonably
request and the Company may exclude from such registration the Registrable
Certificates of any Holder that fails to furnish such information within a
reasonable time after receiving such request. Each Holder as to which any Shelf
Registration is being effected hereby agrees to furnish to the Company all
information with respect to such Holder necessary to make the information
previously furnished to the Company by such Holder not materially misleading.

                  Each Holder agrees that, upon receipt of any notice from the
Company of the happening of any event or the discovery of any facts, each of the
kind described in Sections 2(d)(i)(B) or 3(e)(ii)-(vi) hereof, such Holder will
forthwith discontinue disposition of Registrable Certificates pursuant to such
Registration Statement until such Holder's receipt of the copies of the
supplemented or amended Prospectus contemplated by Section 3(j) hereof or it is
advised in writing by the Company that the use of the applicable Prospectus may
be resumed, and, if so directed by the Company, such Holder will deliver to the
Company (at the Company's expense) all copies in its possession other than
permanent file copies then in such Holder's possession, of the Prospectus
covering such Registrable Certificates current at the time of receipt of such
notice. If the Company shall give any such notice to suspend the disposition of
Registrable Certificates pursuant to a Registration Statement as a result of the
happening of any event or the discovery of any facts, each of the kind described
in Sections 2(d)(i)(B) or 3(e)(ii)-(vi) hereof, the Company shall be deemed to
have used its best efforts to keep the Registration Statement effective during
such period of suspension provided that the Company shall use its best efforts
to file and have declared effective (if an amendment) as soon as practicable an
amendment or supplement to the Registration Statement and shall extend the
period during which the Registration Statement shall be maintained effective
pursuant to this Agreement by the number of days during the period from and
including the date of the giving of such notice to and 



<PAGE>   20
                                       19


including the date when the Holders shall have received copies of the
supplemented or amended Prospectus necessary to resume such dispositions or it
is advised in writing by the Company that the use of the applicable Prospectus
may be resumed.

                  4. Underwritten Offering. The Holders of Registrable
Certificates covered by a Shelf Registration Statement who desire to do so may
sell such Registrable Certificates in an underwritten offering. In any such
underwritten offering, the investment banker or bankers and manager or managers
that will administer the offering will be selected by, and the underwriting
arrangements with respect thereto will be approved by, the Holders of a majority
of the Registrable Securities to be included in such offering; provided,
however, that (i) such investment bankers and managers and underwriting
arrangements must be reasonably satisfactory to the Company and (ii) the Company
shall not be obligated to arrange for more than one underwritten offering during
the period such Shelf Registration Statement is required to be effective
pursuant to Section 2(b)(B) hereof. No Holder may participate in any
underwritten offering contemplated hereby unless such Holder (a) agrees to sell
such Holder's Registrable Certificates in accordance with any approved
underwriting arrangements, (b) completes and executes all reasonable
questionnaires, powers of attorney, indemnities, underwriting agreements,
lock-up letters and other documents required under the terms of such approved
underwriting arrangements and (c) at least 20% of the outstanding Registrable
Certificates are included in such underwritten offering. The Holders
participating in any underwritten offering shall be responsible for any expenses
customarily borne by selling securityholders, including underwriting discounts
and commissions and fees and expenses of counsel to the selling securityholders.

                  5. Indemnification and Contribution. (a) The Company agrees to
indemnify and hold harmless, each Initial Purchaser, each Holder and each
person, if any, who controls any Initial Purchaser or any Holder within the
meaning of either Section 15 of the 1933 Act or Section 20 of the 1934 Act, from
and against all losses, claims, damages and liabilities (including, without
limitation, any legal or other expenses reasonably incurred by any Initial
Purchaser, any Holder or any such controlling person in connection with
defending or investigating any such action or claim) caused by any untrue
statement or alleged untrue statement of a material fact contained in any
Registration Statement (or any amendment thereto) pursuant to which Exchange
Certificates or Registrable Certificates were registered under the 1933 Act,
including all documents incorporated therein by reference, or caused by any
omission or alleged omission to state therein a material fact required to be
stated therein or necessary to make the statements therein not misleading, or
caused by any untrue statement or alleged untrue statement of a material fact
contained in any Prospectus (as amended or supplemented if the Company shall
have furnished any amendments or supplements thereto), or caused by any omission
or alleged omission to state therein a material fact necessary to make the
statements therein in light of the circumstances under which they were made not
misleading, except insofar as such losses, claims, damages or liabilities are
caused by any such untrue statement or omission or alleged untrue statement or
omission based upon information relating to the Initial Purchasers or any Holder
furnished to the Company in writing by the Initial Purchasers or any selling
Holder expressly for use therein; provided, however, that the foregoing
indemnity agreement with respect to any preliminary Prospectus shall not inure
to the benefit of any Person 


<PAGE>   21
                                       20


from whom the Person asserting any such losses, claims, damages or liabilities
purchased Registrable Certificates, or any person controlling such seller, if a
copy of the final Prospectus (as then amended or supplemented if the Company
shall have furnished any amendments or supplements thereto) was not sent or
given by or on behalf of such seller to such purchaser with or prior to the
written confirmation of the sale of the Registrable Certificates to such Person,
and if the final Prospectus (as so amended or supplemented) would have cured the
defect giving rise to such losses, claims, damages or liabilities. In connection
with any underwritten offering permitted by Section 4, the Company will also
indemnify the underwriters participating in the distribution, their officers and
directors and each Person who controls such Persons (within the meaning of the
1933 Act and the 1934 Act) to the same extent as provided above with respect to
the indemnification of the Holders, if requested in connection with any
Registration Statement.

                  (b) Each Holder agrees, severally and not jointly, to
indemnify and hold harmless the Company, each Initial Purchaser, the other
selling Holders, and each of their respective directors, officers who sign the
Registration Statement and each Person, if any, who controls the Company, any
Initial Purchaser and any other selling Holder within the meaning of either
Section 15 of the 1933 Act or Section 20 of the 1934 Act to the same extent as
the foregoing indemnity from the Company to the Initial Purchasers and the
Holders, but only with reference to information relating to such Holder
furnished to the Company in writing by such Holder expressly for use in any
Registration Statement (or any amendment thereto) or any Prospectus (or any
amendment or supplement thereto).

                  (c) In case any proceeding (including any governmental
investigation) shall be instituted involving any person in respect of which
indemnity may be sought pursuant to either paragraph (a) or paragraph (b) above,
such person (the "indemnified party") shall promptly notify the person against
whom such indemnity may be sought (the "indemnifying party") in writing and the
indemnifying party, may elect to or upon request of the indemnified party, shall
retain counsel reasonably satisfactory to the indemnified party to represent the
indemnified party and any others the indemnifying party may designate in such
proceeding and shall pay the fees and disbursements of such counsel related to
such proceeding. In any such proceeding, any indemnified party shall have the
right to retain its own counsel, but the fees and expenses of such counsel shall
be at the expense of such indemnified party unless (i) the indemnifying party
and the indemnified party shall have mutually agreed to the retention of such
counsel or (ii) the named parties to any such proceeding (including any
impleaded parties) include both the indemnifying party and the indemnified party
and representation of both parties by the same counsel would be inappropriate
due to actual or potential differing interests between them. It is understood
that the indemnifying party shall not, in connection with any proceeding or
related proceedings in the same jurisdiction, be liable for the fees and
expenses of more than one separate firm (in addition to any local counsel) for
all such indemnified parties and that such fees and expenses shall be reimbursed
as they are incurred. Such firm shall be designated in writing (i) by the
Initial Purchasers in the case of the Initial Purchasers and related parties
indemnified pursuant to paragraph (a) above, (ii) by the Majority Holders in the
case of the Holders and related parties indemnified pursuant to paragraph (a)
above, and (iii) by the Company in the case of parties indemnified pursuant to
paragraph (b) above. The indemnifying party shall not be liable for any
settlement of any proceeding effected without its written consent but, if
settled 


<PAGE>   22
                                       21


with such consent or if there be a final judgment for the plaintiff, the
indemnifying party agrees to indemnify the indemnified party from and against
any loss or liability by reason of such settlement or judgment. No indemnifying
party shall, without the prior written consent of the indemnified party, effect
any settlement of any pending or threatened proceeding in respect of which such
indemnified party is or could have been a party and indemnity could have been
sought hereunder by such indemnified party, unless such settlement includes an
unconditional release of such indemnified party from all liability on claims
that are the subject matter of such proceeding.

                  (d) If the indemnification provided for in paragraph (a) or
paragraph (b) of this Section 5 is unavailable to an indemnified party or
insufficient in respect of any losses, claims, damages or liabilities, then each
indemnifying party under such paragraph, in lieu of indemnifying such
indemnified party thereunder, shall contribute to the amount paid or payable by
such indemnified party as a result of such losses, claims, damages or
liabilities in such proportion as is appropriate to reflect the relative fault
of the indemnifying party or parties on the one hand and of the indemnified
party or parties on the other hand in connection with the statements or
omissions that resulted in such losses, claims, damages or liabilities, as well
as any other relevant equitable considerations. The relative fault of the
Company and the Holders shall be determined by reference to, among other things,
whether the untrue or alleged untrue statement of a material fact or the
omission or alleged omission to state a material fact relates to information
supplied by the Company or by the Holders and the parties' relative intent,
knowledge, access to information and opportunity to correct or prevent such
statement or omission. The Holders' respective obligations to contribute
pursuant to this Section 5(d) are several in proportion to the respective
aggregate principal amount of Registrable Certificates of such Holder that were
registered pursuant to a Registration Statement.

                  (e) The Company and each Holder agree that it would not be
just or equitable if contribution pursuant to this Section 5 were determined by
pro rata allocation or by any other method of allocation that does not take
account of the equitable considerations referred to in paragraph (d) above. The
amount paid or payable by an indemnified party as a result of the losses,
claims, damages and liabilities referred to in paragraph (d) above shall be
deemed to include, subject to the limitations set forth above, any legal or
other expenses reasonably incurred by such indemnified party in connection with
investigating or defending any such action or claim. Notwithstanding the
provisions of this Section 5, no Holder shall be required to indemnify or
contribute any amount in excess of the amount by which the total price at which
Registrable Certificates were sold by such Holder exceeds the amount of any
damages that such Holder has otherwise been required to pay by reason of such
untrue or alleged untrue statement or omission or alleged omission. No person
guilty of fraudulent misrepresentation (within the meaning of Section 11(f) of
the 1933 Act) shall be entitled to contribution from any person who was not
guilty of such fraudulent misrepresentation. The remedies provided for in this
Section 5 are not exclusive and shall not limit any rights or remedies which may
otherwise be available to any indemnified party at law or in equity.

                  The indemnity and contribution provisions contained in this
Section 5 shall remain operative and in full force and effect regardless of (i)
any termination of this Agreement, 


<PAGE>   23
                                       22


(ii) any investigation made by or on behalf of the Initial Purchasers, any
Holder or any person controlling any Initial Purchaser or any Holder, or by or
on behalf of the Company, its officers or directors or any person controlling
the Company, (iii) acceptance of any of the Exchange Certificates and (iv) any
sale of Registrable Certificates pursuant to a Shelf Registration Statement.

                  6. Miscellaneous. (a) Rule 144 and Rule 144A. For so long as
the Company is subject to the reporting requirements of Section 13 or 15 of the
1934 Act, the Company covenants that it will file the reports required to be
filed by it under Section 13(a) or 15(d) of the 1934 Act and the rules and
regulations adopted by the SEC thereunder, that if it ceases to be so required
to file such reports, it will upon the request of any Holder of Registrable
Certificates (i) make publicly available such information as is necessary to
permit sales pursuant to Rule 144 under the 1933 Act, (ii) deliver such
information to a prospective purchaser as is necessary to permit sales pursuant
to Rule 144A under the 1933 Act, and (iii) take such further action that is
reasonable in the circumstances, in each case, to the extent required from time
to time to enable such Holder to sell its Registrable Certificates without
registration under the 1933 Act within the limitation of the exemptions provided
by (x) Rule 144 under the 1933 Act, as such Rule may be amended from time to
time, (y) Rule 144A under the 1933 Act, as such Rule may be amended from time to
time, or (z) any similar rules or regulations hereafter adopted by the SEC. Upon
the reasonable request of any Holder of Registrable Certificates, the Company
will deliver to such Holder a written statement as to whether it has complied
with such requirements.

                  (b) Purchase and Sale of Certificates. The Company shall not,
and the Company shall use its best efforts to cause its affiliates (as defined
in Rule 405 under the 1933 Act) not to, purchase and then resell or otherwise
transfer any Initial Certificates.

                  (c) Trustees. The Trustees shall take such action as may be
reasonably requested by the Company in connection with the Company satisfying
its obligations arising under this Agreement; provided that the Company shall
provide to the Trustee (as Trustee and in its individual capacity) such
indemnity in connection therewith as the Trustee may reasonably request, subject
to any separate fee arrangement between the Company and the Trustee.

                  (d) No Inconsistent Agreements. The Company has not entered
into nor will the Company on or after the date of this Agreement enter into any
agreement which is inconsistent with the rights granted to the Holders of
Registrable Certificates in this Agreement or otherwise conflicts with the
provisions hereof.

                  (e) Amendments and Waivers. Except as otherwise expressly
permitted in the Pass Through Trust Agreements or the Successor Pass Through
Trust Agreements, the provisions of this Agreement, including the provisions of
this sentence, may not be amended, modified or supplemented, and waivers or
consents to departures from the provisions hereof may not be given unless the
Company has obtained the written consent of Holders of at least a majority in
aggregate principal amount of the outstanding Registrable Certificates affected
by such amendment, modification, supplement, waiver or departure; provided,
however, that no amendment, modification, supplement or waiver or consent to any
departure from the provisions 


<PAGE>   24
                                       23


of Section 5 hereof shall be effective as against any Holder of Registrable
Certificates unless consented to in writing by such Holder.

                  (f) Notices. All notices and other communications provided for
or permitted hereunder shall be made in writing by hand-delivery, registered
first-class mail, telex, telecopier, or any courier guaranteeing overnight
delivery (i) if to a Holder, at the most current address given by such Holder to
the Company by means of a notice given in accordance with the provisions of this
Section 6(f), which address initially is, with respect to the Initial
Purchasers, the address set forth in the Purchase Agreement; and (ii) if to the
Company, initially at the Company's address set forth in the Purchase Agreement
and thereafter at such other address, notice of which is given in accordance
with the provisions of this Section 6(f).

                  All such notices and communications shall be deemed to have
been duly given when received or, if made by facsimile or telecommunication
transmission, when received unless received outside of business hours, in which
case on the next open of business on a Business Day.

                  Copies of all such notices, demands, or other communications
shall be concurrently delivered by the person giving the same to the Trustees,
at the address specified in the Pass Through Trust Agreements or the Successor
Pass Through Trust Agreements, as the case may be.

                  (g) Successors and Assigns. This Agreement shall inure to the
benefit of and be binding upon the successors, assigns and transferees of each
of the parties, including, without limitation and without the need for an
express assignment, subsequent Holders; provided that nothing herein shall be
deemed to permit any assignment, transfer or other disposition of Registrable
Certificates in violation of the terms hereof or of the Purchase Agreement or
the Pass Through Trust Agreements or Successor Pass Through Trust Agreements. If
any transferee of any Holder shall acquire Registrable Certificates, in any
manner, whether by operation of law or otherwise, such Registrable Certificates
shall be held subject to all of the terms of this Agreement, and by taking and
holding such Registrable Certificates, such Person shall be conclusively deemed
to have agreed to be bound by and to perform all of the terms and provisions of
this Agreement, including the restrictions on resale set forth in this Agreement
and, if applicable, the Purchase Agreement, and such Person shall be entitled to
receive the benefits hereof. Upon the occurrence of the transfers contemplated
by the Assignment and Assumption Agreements (as defined in the Pass Through
Trust Agreements), the trustee of each Original Trust shall (without any further
act) be deemed to have transferred all of its rights, title and interest in and
to this Agreement to the trustee of the corresponding Successor Trust and,
thereafter, the trustee of each Successor Trust shall be deemed to be the
"Trustee" of such Successor Trust with the rights and obligations of a "Trustee"
hereunder. The Initial Purchasers (in their capacity as Initial Purchasers)
shall have no liability or obligation to the Company with respect to any failure
by any other Holder to comply with, or any breach by any other Holder of, any of
the obligations of such other Holder under this Registration Rights Agreement.
<PAGE>   25
                                       24


                  (h) Third Party Beneficiaries. The Holders shall be third
party beneficiaries to the agreements made hereunder and to the obligations of
the Company hereunder and shall have the right to enforce such agreements and
obligations directly to the extent any such Holder deems such enforcement
necessary or advisable to protect the rights expressed to be for its benefit
hereunder.

                  (i) Counterparts. This Agreement may be executed in any number
of counterparts and by the parties hereto in separate counterparts, each of
which when so executed shall be deemed to be an original and all of which taken
together shall constitute one and the same agreement.

                  (j) Headings. The headings in this Agreement are for
convenience of reference only and shall not limit or otherwise affect the
meaning hereof.

                  (k) GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

                  (l) Severability. In the event that any one or more of the
provisions contained herein, or the application thereof in any circumstance, is
held invalid, illegal or unenforceable, the validity, legality and
enforceability of any such provision in every other respect and of the remaining
provisions contained herein shall not be affected or impaired thereby.



<PAGE>   26
                                       25




                  IN WITNESS WHEREOF, the parties have executed this Agreement
as of the date first written above.

                                   AMERICA WEST AIRLINES, INC.


                                   By:   /s/ W. Douglas Parker
                                      ------------------------------------
                                         Name:  W. Douglas Parker
                                         Title: Sr. Vice President & CFO


                                   WILMINGTON TRUST COMPANY,
                                     not in its individual capacity
                                     but solely as Trustee under
                                     each of the Original Trusts



                                   By:   /s/ Jill K. Morrison
                                      ------------------------------------
                                         Name:  Jill K. Morrison
                                         Title: Administrative Account Manager


Confirmed and accepted as of 
the date first above written:

MORGAN STANLEY & CO. INCORPORATED
DONALDSON, LUFKIN & JENRETTE SECURITIES CORPORATION
MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED
SALOMON SMITH BARNEY INC.

By:      MORGAN STANLEY & CO. INCORPORATED



         By:    /s/ Tom Cahill                              
            ------------------------------
                Name:  Tom Cahill
                Title:





<PAGE>   1
                                                                    Exhibit 4.15










                                DEPOSIT AGREEMENT
                                    (Class A)

                           Dated as of October 6, 1998


                                     between


                            WILMINGTON TRUST COMPANY

                                 as Escrow Agent


                                       and


                               ABN AMRO BANK N.V.,
                                 Chicago Branch

                                  as Depositary
<PAGE>   2
         DEPOSIT AGREEMENT (Class A) dated as of October 6, 1998 (as amended,
modified or supplemented from time to time, this "Agreement") between WILMINGTON
TRUST COMPANY, a Delaware banking corporation, as Escrow Agent under the Escrow
and Paying Agent Agreement referred to below (in such capacity, together with
its successors in such capacity, the "Escrow Agent"), and ABN AMRO BANK N.V., a
bank organized under the laws of the Netherlands, acting through its Chicago
branch, as depositary bank (the "Depositary").

                               W I T N E S S E T H

         WHEREAS, America West Airlines, Inc. ("America West") and Wilmington
Trust Company, not in its individual capacity except as otherwise expressly
provided therein, but solely as trustee (in such capacity, together with its
successors in such capacity, the "Pass Through Trustee") have entered into a
Pass Through Trust Agreement dated as of October 6, 1998 (as amended, modified
or supplemented from time to time in accordance with the terms thereof, the
"Pass Through Trust Agreement") relating to America West Airlines Pass Through
Trust 1998-1A-O pursuant to which the America West Airlines Pass Through Trust,
Series 1998-1A-O Certificates referred to therein (the "Certificates") are being
issued;

         WHEREAS, America West and Morgan Stanley & Co. Incorporated, Donaldson,
Lufkin & Jenrette Securities Corporation, Merrill Lynch, Pierce, Fenner & Smith
Incorporated and Salomon Smith Barney Inc. (collectively, the "Initial
Purchasers" and, together with their respective transferees and assigns as
registered owners of the Certificates, the "Investors") have entered into a
Purchase Agreement dated as of October 6, 1998 pursuant to which the Pass
Through Trustee will issue and sell the Certificates to the Initial Purchasers
(the net proceeds of such sale being herein referred to as the "Net Proceeds");

         WHEREAS, America West, the Pass Through Trustee, certain other pass
through trustees and certain other persons concurrently herewith are entering
into the Note Purchase Agreement, dated as of the date hereof (the "Note
Purchase Agreement"), pursuant to which the Pass Through Trustee has agreed to
acquire from time to time on or prior to the Delivery Period Termination Date
(as defined in the Note Purchase Agreement) equipment notes (the "Equipment
Notes") issued to finance or refinance the acquisition of aircraft by America
West, as lessee or as owner, utilizing a portion of the Net Proceeds;

         WHEREAS, the Escrow Agent, the Initial Purchasers, the Pass Through
Trustee and Wilmington Trust Company, as paying agent for the Escrow Agent (in
such capacity, together with its successors in such capacity, the "Paying
Agent") concurrently herewith are entering into an Escrow and Paying Agent
Agreement, dated as of the date hereof (as amended, modified or supplemented
from time to time in accordance with the terms thereof, the "Escrow and Paying
Agent Agreement"); and
<PAGE>   3
                                                   [Deposit Agreement (Class A)]

         WHEREAS, the Initial Purchasers and the Pass Through Trustee intend
that the Net Proceeds be held in escrow by the Escrow Agent on behalf of the
Investors pursuant to the Escrow and Paying Agent Agreement, subject to
withdrawal upon request of and proper certification by the Pass Through Trustee
for the purpose of purchasing Equipment Notes, and that pending such withdrawal
the Net Proceeds be deposited by the Escrow Agent with the Depositary pursuant
to this Agreement, which provides for the Depositary to pay interest for
distribution to the Investors and to establish accounts from which the Escrow
Agent shall make withdrawals upon request of and proper certification by the
Pass Through Trustee.

         NOW, THEREFORE, in consideration of the obligations contained herein,
and for other good and valuable consideration, the receipt and sufficiency of
which is hereby acknowledged, the parties hereto hereby agree as follows:

         SECTION 1.1 Acceptance of Depositary. The Depositary hereby agrees to
act as depositary bank as provided herein and in connection therewith to accept
all amounts to be delivered to or held by the Depositary pursuant to the terms
of this Agreement. The Depositary further agrees to hold, maintain and safeguard
the Deposits and the Accounts (as defined below) during the term of this
Agreement in accordance with the provisions of this Agreement. The Escrow Agent
shall not have any right to withdraw, assign or otherwise transfer moneys held
in the Accounts except as permitted by this Agreement.

         SECTION 1.2 Establishment of Accounts. The Escrow Agent hereby
instructs the Depositary, and the Depositary agrees, to establish the separate
deposit accounts listed on Schedule I hereto and to establish such additional
separate deposit accounts as may be required in connection with the deposits
contemplated by Section 2.4 hereof (each, an "Account" and collectively, the
"Accounts"), each in the name of the Escrow Agent and all on the terms and
conditions set forth in this Agreement.

         SECTION 1.3 Deposits. The Escrow Agent shall direct the Initial
Purchasers to deposit with the Depositary on the date of this Agreement (the
"Deposit Date") in Federal (same day) funds by wire transfer to: Federal Reserve
Bank, New York, ABN NY ABA #026009580, Account: Chicago Treasury, Reference:
America West Deposit, and the Depositary shall accept from the Initial
Purchasers, on behalf of the Escrow Agent, the sum of US$131,670,000.00. Upon
acceptance of such sum, the Depositary shall (i) establish each of the deposits
specified in Schedule I hereto maturing on the respective dates set forth
therein (including any deposit made pursuant to Section 2.4 hereof,
individually, a "Deposit" and, collectively, the "Deposits") and (ii) credit
each Deposit to the related Account as set forth therein. No amount shall be
deposited in any Account other than the related Deposit.

                                       2
<PAGE>   4
                                                   [Deposit Agreement (Class A)]

         SECTION 1.4 Interest. (a) Each Deposit shall bear interest from and
including the date of deposit to but excluding the date of withdrawal at the
rate of 6.87% per annum (computed on the basis of a year of twelve 30-day
months) payable to the Paying Agent on behalf of the Escrow Agent semi-annually
in arrears on each January 2 and July 2 commencing on January 2, 1999 (each, an
"Interest Payment Date") and, as provided in Section 2.3(b) hereof, on the date
of the Final Withdrawal (as defined below), all in accordance with the terms of
this Agreement (whether or not any such Deposit is withdrawn on an Interest
Payment Date). Interest accrued on any Deposit that is withdrawn pursuant to a
Notice of Purchase Withdrawal (as defined below) shall be paid on the next
Interest Payment Date, notwithstanding any intervening Final Withdrawal (as
defined below) of all of the remaining Deposits (any such Deposits consisting of
unpaid interest only and remaining after a Final Withdrawal may be referred to
as the "Carryover Deposits").

                  (b) The parties hereto further acknowledge and agree that upon
any increase in the rate of interest on the Certificates (such increase referred
to as a "Rate Increase") pursuant to the terms of the Registration Rights
Agreement, the rate of interest borne by each Deposit in accordance with Section
2.2(a) above shall increase by the amount of such Rate Increase, and upon any
subsequent decrease in the rate of interest on the Equipment Notes (such
decrease referred to as a "Rate Decrease") pursuant to the terms of the
Registration Rights Agreement, the rate of interest borne by such Deposit shall
decrease by the amount of such Rate Decrease. For the purposes of this Section
2.2(b), "Registration Rights Agreement" means the Exchange and Registration
Rights Agreement dated the date hereof among America West, the Pass Through
Trustee, certain other pass through trustees and the Initial Purchasers.

         SECTION 1.5 Withdrawals. (a) On and after the date seven days after the
establishment of any Deposit, the Escrow Agent may, by providing at least one
Business Day's prior notice of withdrawal to the Depositary in the form of
Exhibit A hereto (a "Notice of Purchase Withdrawal"), withdraw not less than the
entire principal balance of such Deposit, except that at any time prior to the
actual withdrawal of such Deposit, the Escrow Agent or the Pass Through Trustee
may, by notice to the Depositary, cancel such withdrawal (including on the
scheduled date therefor), and thereafter such Deposit shall continue to be
maintained by the Depositary in accordance with the original terms thereof.
Following such withdrawal the balance in the related Account shall be zero and
the Depositary shall, subject to the Depositary's payment obligation pursuant to
the last sentence of Section 2.2(a) hereof, close such Account. As used herein,
"Business Day" means any day, other than a Saturday, Sunday or other day on
which commercial banks are authorized or required by law to close in New York,
New York, Chicago, Illinois, Phoenix, Arizona, Hartford, Connecticut or
Wilmington, Delaware.

                  (b) The Escrow Agent may, subject to Section 1.02(d) of the
Escrow and Paying Agent Agreement, by providing at least 15 days' prior notice
of withdrawal to the

                                       3
<PAGE>   5
                                                   [Deposit Agreement (Class A)]

Depositary in the form of Exhibit B hereto (a "Notice of Final Withdrawal"),
withdraw the entire amount of all of the remaining Deposits together with the
payment by the Depositary of all accrued and unpaid interest on such Deposits to
but excluding the specified date of withdrawal (a "Final Withdrawal"), on such
date as shall be specified in such Notice of Final Withdrawal. If a Notice of
Final Withdrawal has not been given to the Depositary on or before February 7,
2000 and there are unwithdrawn Deposits on such date, the Depositary shall pay
the amount of the Final Withdrawal to the Paying Agent on February 28, 2000.

                  (c) If the Depositary receives a duly completed Notice of
Purchase Withdrawal or Notice of Final Withdrawal (each, a "Withdrawal Notice")
complying with the provisions of this Agreement, it shall make the payments
specified therein in accordance with the provisions of this Agreement. If such
complying Withdrawal Notice is received by the Depositary no later than 3:00
p.m. on a Business Day, the Depositary shall make the payments requested in such
Withdrawal Notice no later than 11:00 a.m. on the next succeeding Business Day
or such later day specified in such Withdrawal Notice, and if such complying
Withdrawal Notice is received by the Depositary after 3:00 p.m. on a Business
Day, the Depositary shall make the payments requested in such Withdrawal Notice
no later than 11:00 a.m. on the second Business Day next following such Business
Day.

         SECTION 1.6 Other Accounts. On the date of withdrawal of any Deposit,
the Escrow Agent, or the Pass Through Trustee on behalf of the Escrow Agent,
shall be entitled to re-deposit with the Depositary any portion thereof and the
Depositary shall accept the same for deposit hereunder. Any sums so received for
deposit shall be established as a new Deposit and credited to a new Account, all
as more fully provided in Section 2.1 hereof, and thereafter the provisions of
this Agreement shall apply thereto as fully and with the same force and effect
as if such Deposit had been established on the Deposit Date except that (i) such
Deposit may not be withdrawn prior to the date seven days after the
establishment thereof and (ii) such Deposit shall mature on February 28, 2000
and bear interest as provided in Section 2.2. The Depositary shall promptly give
notice to the Escrow Agent of receipt of each such re-deposit and the account
number assigned thereto.

         SECTION 2. Termination. This Agreement shall terminate on the fifth
Business Day after the later of the date on which (i) all of the Deposits shall
have been withdrawn and paid as provided herein without any re-deposit and (ii)
all accrued and unpaid interest on the Deposits shall have been paid as provided
herein, but in no event prior to the date on which the Depositary shall have
performed in full its obligations hereunder.

         SECTION 3. Payments. All payments (including, without limitation, those
payments made in respect of Taxes (as defined and provided for below)) made by
the Depositary hereunder shall be paid in United States Dollars and immediately
available funds by wire transfer (i) in the

                                       4
<PAGE>   6
                                                   [Deposit Agreement (Class A)]

case of accrued interest on the Deposits payable under Section 2.2 hereof or any
Final Withdrawal, directly to the Paying Agent at Wilmington Trust Company,
Wilmington, Delaware, ABA# 031-100-092, for credit to the account of America
West 1998-1 (Subordination Account), Account No. 46427-1, Attention: Rosemary
Pantano, Telephone No. (302) 427-4805, Reference: America West 1998-1A, or to
such other account as the Paying Agent may direct from time to time in writing
to the Depositary and the Escrow Agent and (ii) in the case of any withdrawal of
one or more Deposits pursuant to a Notice of Purchase Withdrawal, directly to or
as directed by the Pass Through Trustee as specified and in the manner provided
in such Notice of Purchase Withdrawal. The Depositary hereby waives any and all
rights of set-off, combination of accounts, right of retention or similar right
(whether arising under applicable law, contract or otherwise) it may have
against the Deposits howsoever arising. All payments on or in respect of each
Deposit shall be made free and clear of and without reduction for or on account
of any and all taxes, levies or other impositions or charges (collectively,
"Taxes"). However, if the Depositary or the Paying Agent (pursuant to Section
2.04 of the Escrow and Paying Agent Agreement) shall be required by law to
deduct or withhold any Taxes from or in respect of any sum payable hereunder,
the Depositary shall (i) make such deductions or withholding, (ii) pay the full
amount deducted or withheld (including in respect of such additional amounts) to
the competent taxation authority and (iii) if the Taxes required to be deducted
or withheld are imposed by the Netherlands or any political subdivision thereof,
pay such additional amounts as may be necessary in order that the actual amount
received by the designated recipient of such sum under this Agreement or the
Escrow and Paying Agent Agreement after such deduction or withholding equals the
sum it would have received had no such deduction or withholding been required.
If the date on which any payment due on any Deposit would otherwise fall on a
day which is not a Business Day, such payment shall be made on the next
succeeding Business Day, and no additional interest shall accrue in respect of
such extension.

         SECTION 4. Representation and Warranties. The Depositary hereby
represents and warrants to America West, the Escrow Agent, the Pass Through
Trustee, the Initial Purchasers and the Paying Agent that:

                  (1) it is a bank duly organized and validly existing in good
standing under the laws of its jurisdiction of organization and is duly
qualified to conduct banking business in the State of Illinois through its
Chicago branch;

                  (2) it has full power, authority and legal right to conduct
its business and operations as currently conducted and to enter into and perform
its obligations under this Agreement;

                  (3) the execution, delivery and performance of this Agreement
have been duly authorized by all necessary corporate action on the part of it
and do not require any stockholder

                                       5
<PAGE>   7
                                                   [Deposit Agreement (Class A)]

approval, or approval or consent of any trustee or holder of any indebtedness or
obligations of it, and such document has been duly executed and delivered by it
and constitutes its legal, valid and binding obligations enforceable against it
in accordance with the terms hereof;

                  (4) no authorization, consent or approval of or other action
by, and no notice to or filing with, any United States federal or state
governmental authority or regulatory body is required for the execution,
delivery or performance by it of this Agreement;

                  (5) neither the execution, delivery or performance by it of
this Agreement, nor compliance with the terms and provisions hereof, conflicts
or will conflict with or results or will result in a breach or violation of any
of the terms, conditions or provisions of, or will require any consent or
approval under, any law, governmental rule or regulation or the charter
documents, as amended, or bylaws, as amended, of it or any similar instrument
binding on it or any order, writ, injunction or decree of any court or
governmental authority against it or by which it or any of its properties is
bound or any indenture, mortgage or contract or other agreement or instrument to
which it is a party or by which it or any of its properties is bound, or
constitutes or will constitute a default thereunder or results or will result in
the imposition of any lien upon any of its properties; and

                  (6) there are no pending or, to its knowledge, threatened
actions, suits, investigations or proceedings (whether or not purportedly on
behalf of it) against or affecting it or any of its property before or by any
court or administrative agency which, if adversely determined, (i) would
adversely affect the ability of it to perform its obligations under this
Agreement or (ii) would call into question or challenge the validity of this
Agreement or the enforceability hereof in accordance with the terms hereof, nor
is the Depositary in default with respect to any order of any court,
governmental authority, arbitration board or administrative agency so as to
adversely affect its ability to perform its obligations under this Agreement.

         SECTION 5. Transfer. Neither party hereto shall be entitled to assign
or otherwise transfer this Agreement (or any interest herein) other than (in the
case of the Escrow Agent) to a successor escrow agent under the Escrow and
Paying Agent Agreement, and any purported assignment in violation thereof shall
be void. This Agreement shall be binding upon the parties hereto and their
respective successors and (in the case of the Escrow Agent) permitted assigns.
Upon the occurrence of the Transfer (as defined below) contemplated by the
Assignment and Assumption Agreement (as defined below), the Pass Through Trustee
shall (without further act) be deemed to have transferred all of its right,
title and interest in and to this Agreement to the trustee of the Successor
Trust (as defined below) and, thereafter, the trustee of the Successor Trust
shall be deemed to be the "Pass Through Trustee" hereunder with the rights of
the "Pass Through Trustee" hereunder, and each reference herein to "America West
Airlines Pass Through Trust 1998-1A-O" shall be deemed to be a reference to
"America West Airlines Pass Through

                                       6
<PAGE>   8
                                                   [Deposit Agreement (Class A)]

Trust 1998-1A-S". The Escrow Agent and the Depositary hereby acknowledge and
consent to the Transfer contemplated by the Assignment and Assumption Agreement.
For the purposes of this Section 6, "Transfer" means the transfer contemplated
by the Assignment and Assumption Agreement; "Assignment and Assumption
Agreement" means the Assignment and Assumption Agreement to be entered into
between the Pass Through Trustee and the trustee of the Successor Trust,
substantially in the form of Exhibit D to the Pass Through Trust Agreement; and
"Successor Trust" means the America West Airlines Pass Through Trust 1998-1A-S.

         SECTION 6. Amendment, Etc. This Agreement may not be amended, waived or
otherwise modified except by an instrument in writing signed by the party
against whom the amendment, waiver or other modification is sought to be
enforced and by the Pass Through Trustee.

         SECTION 7. Notices. Unless otherwise expressly provided herein, any
notice or other communication under this Agreement shall be in writing
(including by facsimile) and shall be deemed to be given and effective upon
receipt thereof (or, if received after normal business hours, the next open of
business on a Business Day). All notices shall be sent to (x) in the case of the
Depositary, ABN AMRO BANK N.V., 135 South LaSalle Street, Chicago, Illinois
60603, Attention: Vice President - Aerospace (Telecopier: 312-606-8428), with a
copy to ABN AMRO Bank N.V., Chicago Branch, 181 W. Madison Street, Chicago,
Illinois 60602, Attention: Money Market Desk (Telecopier: 312-904-9106) or (y)
in the case of the Escrow Agent, Wilmington Trust Company, 1100 North Market
Street, Wilmington, Delaware 19890, Attention: Corporate Trust Administration
(Telecopier: (302) 651-8882), in each case, with a copy to the Pass Through
Trustee, Wilmington Trust Company, 1100 North Market Street, Wilmington,
Delaware 19890, Attention: Corporate Trust Administration (Telecopier: (302)
651-8882) and to America West, America West Airlines, Inc., 4000 East Sky Harbor
Boulevard, Phoenix, Arizona 95043, Attention: Senior Vice President-Legal
Affairs (Telecopier: (602) 693-5904) (or at such other address as any such party
may specify from time to time in a written notice to the parties hereto). On or
prior to the execution of this Agreement, the Escrow Agent has delivered to the
Depositary a certificate containing specimen signatures of the representatives
of the Escrow Agent who are authorized to give notices and instructions with
respect to this Agreement. The Depositary may conclusively rely on such
certificate until the Depositary receives written notice from the Escrow Agent
to the contrary.

         SECTION 8. Obligations Unconditional. The Depositary hereby
acknowledges and agrees that its obligation to repay each Deposit together with
interest thereon as provided herein is absolute, irrevocable and unconditional
and constitutes a full recourse obligation of the Depositary enforceable against
it to the full extent of all of its assets and properties.

                                       7
<PAGE>   9
                                                   [Deposit Agreement (Class A)]

         SECTION 9. Entire Agreement. This Agreement (including all attachments
hereto) sets forth all of the promises, covenants, agreements, conditions and
understandings between the Depositary and the Escrow Agent with respect to the
subject matter hereof and supersedes all prior and contemporaneous agreements
and undertakings, inducements or conditions, express or implied, oral or
written.

         SECTION 10. Governing Law. This Agreement, and the rights and
obligations of the Depositary and the Escrow Agent with respect to the Deposits,
shall be governed by, and construed in accordance with, the law of the State of
New York.

         SECTION 11. Waiver of Jury Trial Right. EACH OF THE DEPOSITARY AND THE
ESCROW AGENT ACKNOWLEDGES AND ACCEPTS THAT IN ANY SUIT, ACTION OR PROCEEDING
ARISING OUT OF OR RELATING TO THIS AGREEMENT SUCH PARTY IRREVOCABLY WAIVES ITS
RIGHT TO A TRIAL BY JURY.

         SECTION 12. Counterparts. This Agreement may be executed in one or more
counterparts, all of which taken together shall constitute one instrument.

         SECTION 13. Head Office Obligation. ABN AMRO Bank N.V. hereby agrees
that the obligations of the Depositary hereunder are also the obligations of ABN
AMRO Bank N.V.'s Head Office in the Netherlands. Accordingly, any beneficiary of
this Agreement will be able to proceed directly against ABN AMRO Bank N.V.'s
Head Office in the Netherlands if ABN AMRO Bank N.V.'s Chicago branch defaults
in its obligation to such beneficiary under this Agreement.


                                      * * *

                                       8
<PAGE>   10
                                                   [Deposit Agreement (Class A)]

                  IN WITNESS WHEREOF, the Escrow Agent and the Depositary have
caused this Deposit Agreement to be duly executed as of the day and year first
above written.



                                       WILMINGTON TRUST COMPANY,
                                          as Escrow Agent


                                       By:       /s/ Jill K. Morrison
                                          -------------------------------------
                                          Name:  Jill K. Morrison
                                          Title: Administrative Account Manager



                                       ABN AMRO BANK N.V., CHICAGO BRANCH,
                                       as Depositary



                                       By:       /s/ Claudia C. Heldring
                                          -------------------------------------
                                          Name:  Claudia C. Heldring
                                          Title: Vice President



                                       By:       /s/ Carla S. Waggoner
                                          -------------------------------------
                                          Name:  Carla S. Waggoner
                                          Title: Assistant Vice President

                                       9
<PAGE>   11
                                                   [Deposit Agreement (Class A)]


                                   Schedule I

                              Schedule of Deposits
                                    (Class A)


<TABLE>
<CAPTION>
Date              Deposit Amount            Account No.             Maturity Date
- ----              --------------            -----------             -------------
<S>               <C>                       <C>                     <C>
11/1/98             15,299,974                D157563                  2/28/00
12/1/98             15,401,413                D157556                  2/28/00
12/1/98             15,401,413                D157559                  2/28/00
 2/1/99             18,520,740                D157551                  2/28/00
 5/1/99             18,736,533                D157548                  2/28/00
 7/1/99             16,117,000                D157543                  2/28/00
 7/1/99             16,117,000                D157544                  2/28/00
 8/1/99             16,075,927                D157537                  2/28/00
                    ----------
                   131,670,000
</TABLE>
<PAGE>   12
                                                   [Deposit Agreement (Class A)]

                                    EXHIBIT A

                          NOTICE OF PURCHASE WITHDRAWAL



ABN AMRO BANK N.V.
135 South LaSalle Street
Chicago, Illinois  60603
Attention: Lukas van der Hoef
Telecopier: (312) 606-8428

Gentlemen:

         Reference is made to the Deposit Agreement (Class A) dated as of
____________, 1998 (the "Deposit Agreement") between Wilmington Trust Company,
as Escrow Agent, and ABN AMRO Bank N.V., Chicago Branch, as Depositary (the
"Depositary").

         In accordance with Section 2.3(a) of the Deposit Agreement, the
undersigned hereby requests the withdrawal of the entire amount of the Deposit,
$_______, Account No. ____________.

         The undersigned hereby directs the Depositary to pay the proceeds of
the Deposit to [________________, Account No. _____, Reference: _________] on
_________ __, 199_, upon the telephonic request of a representative of the Pass
Through Trustee.


                                       WILMINGTON TRUST COMPANY,
                                       as Escrow Agent



                                       By:
                                          -------------------------------------
                                          Name:
                                               --------------------------------
                                          Title:
                                                -------------------------------


Dated:            , 199
      ------------     ----
<PAGE>   13
                                                   [Deposit Agreement (Class A)]

                                    EXHIBIT B

                           NOTICE OF FINAL WITHDRAWAL



ABN AMRO BANK N.V.
135 South LaSalle Street
Chicago, Illinois  60603
Attention: Lukas van der Hoef
Telecopier: (312) 606-8428

Gentlemen:

         Reference is made to the Deposit Agreement (Class A) dated as of
______________, 1998 (the "Deposit Agreement") between Wilmington Trust Company,
as Escrow Agent, and ABN AMRO Bank N.V., Chicago Branch, as Depositary (the
"Depositary").

         In accordance with Section 2.3(b) of the Deposit Agreement, the
undersigned hereby requests the withdrawal of the entire amount of all Deposits
for payment on _______________, 199__.

         The undersigned hereby directs the Depositary to pay the proceeds of
the Deposits and accrued interest thereon to the Paying Agent at
__________________________, ABA# _____________, Account No. _____________,
Reference: America West 1998-1.


                                       WILMINGTON TRUST COMPANY,
                                       as Escrow Agent



                                       By:
                                          -------------------------------------
                                          Name:
                                               --------------------------------
                                          Title:
                                                -------------------------------

Dated:           , 199
      -----------     ----
<PAGE>   14


                                                   [Deposit Agreement (Class A)]



<PAGE>   1
                                                                    Exhibit 4.16










                                DEPOSIT AGREEMENT
                                    (Class B)

                           Dated as of October 6, 1998


                                     between


                            WILMINGTON TRUST COMPANY

                                 as Escrow Agent


                                       and


                               ABN AMRO BANK N.V.,
                                 Chicago Branch

                                  as Depositary
<PAGE>   2
         DEPOSIT AGREEMENT (Class B) dated as of October 6, 1998 (as amended,
modified or supplemented from time to time, this "Agreement") between WILMINGTON
TRUST COMPANY, a Delaware banking corporation, as Escrow Agent under the Escrow
and Paying Agent Agreement referred to below (in such capacity, together with
its successors in such capacity, the "Escrow Agent"), and ABN AMRO BANK N.V., a
bank organized under the laws of the Netherlands, acting through its Chicago
branch, as depositary bank (the "Depositary").

                               W I T N E S S E T H

         WHEREAS, America West Airlines, Inc. ("America West") and Wilmington
Trust Company, not in its individual capacity except as otherwise expressly
provided therein, but solely as trustee (in such capacity, together with its
successors in such capacity, the "Pass Through Trustee") have entered into a
Pass Through Trust Agreement dated as of October 6, 1998 (as amended, modified
or supplemented from time to time in accordance with the terms thereof, the
"Pass Through Trust Agreement") relating to America West Airlines Pass Through
Trust 1998-1B-O pursuant to which the America West Airlines Pass Through Trust,
Series 1998-1B-O Certificates referred to therein (the "Certificates") are being
issued;

         WHEREAS, America West and Morgan Stanley & Co. Incorporated, Donaldson,
Lufkin & Jenrette Securities Corporation, Merrill Lynch, Pierce, Fenner & Smith
Incorporated and Salomon Smith Barney Inc. (collectively, the "Initial
Purchasers" and, together with their respective transferees and assigns as
registered owners of the Certificates, the "Investors") have entered into a
Purchase Agreement dated as of October 6, 1998 pursuant to which the Pass
Through Trustee will issue and sell the Certificates to the Initial Purchasers
(the net proceeds of such sale being herein referred to as the "Net Proceeds");

         WHEREAS, America West, the Pass Through Trustee, certain other pass
through trustees and certain other persons concurrently herewith are entering
into the Note Purchase Agreement, dated as of the date hereof (the "Note
Purchase Agreement"), pursuant to which the Pass Through Trustee has agreed to
acquire from time to time on or prior to the Delivery Period Termination Date
(as defined in the Note Purchase Agreement) equipment notes (the "Equipment
Notes") issued to finance or refinance the acquisition of aircraft by America
West, as lessee or as owner, utilizing a portion of the Net Proceeds;

         WHEREAS, the Escrow Agent, the Initial Purchasers, the Pass Through
Trustee and Wilmington Trust Company, as paying agent for the Escrow Agent (in
such capacity, together with its successors in such capacity, the "Paying
Agent") concurrently herewith are entering into an Escrow and Paying Agent
Agreement, dated as of the date hereof (as amended, modified or supplemented
from time to time in accordance with the terms thereof, the "Escrow and Paying
Agent Agreement"); and
<PAGE>   3
                                                   [Deposit Agreement (Class B)]

         WHEREAS, the Initial Purchasers and the Pass Through Trustee intend
that the Net Proceeds be held in escrow by the Escrow Agent on behalf of the
Investors pursuant to the Escrow and Paying Agent Agreement, subject to
withdrawal upon request of and proper certification by the Pass Through Trustee
for the purpose of purchasing Equipment Notes, and that pending such withdrawal
the Net Proceeds be deposited by the Escrow Agent with the Depositary pursuant
to this Agreement, which provides for the Depositary to pay interest for
distribution to the Investors and to establish accounts from which the Escrow
Agent shall make withdrawals upon request of and proper certification by the
Pass Through Trustee.

         NOW, THEREFORE, in consideration of the obligations contained herein,
and for other good and valuable consideration, the receipt and sufficiency of
which is hereby acknowledged, the parties hereto hereby agree as follows:

         SECTION 1.1 Acceptance of Depositary. The Depositary hereby agrees to
act as depositary bank as provided herein and in connection therewith to accept
all amounts to be delivered to or held by the Depositary pursuant to the terms
of this Agreement. The Depositary further agrees to hold, maintain and safeguard
the Deposits and the Accounts (as defined below) during the term of this
Agreement in accordance with the provisions of this Agreement. The Escrow Agent
shall not have any right to withdraw, assign or otherwise transfer moneys held
in the Accounts except as permitted by this Agreement.

         SECTION 1.2 Establishment of Accounts. The Escrow Agent hereby
instructs the Depositary, and the Depositary agrees, to establish the separate
deposit accounts listed on Schedule I hereto and to establish such additional
separate deposit accounts as may be required in connection with the deposits
contemplated by Section 2.4 hereof (each, an "Account" and collectively, the
"Accounts"), each in the name of the Escrow Agent and all on the terms and
conditions set forth in this Agreement.

         SECTION 1.3 Deposits. The Escrow Agent shall direct the Initial
Purchasers to deposit with the Depositary on the date of this Agreement (the
"Deposit Date") in Federal (same day) funds by wire transfer to: Federal Reserve
Bank, New York, ABN NY ABA #026009580, Account: Chicago Treasury, Reference:
America West Deposit, and the Depositary shall accept from the Initial
Purchasers, on behalf of the Escrow Agent, the sum of US$41,154,000.00. Upon
acceptance of such sum, the Depositary shall (i) establish each of the deposits
specified in Schedule I hereto maturing on the respective dates set forth
therein (including any deposit made pursuant to Section 2.4 hereof,
individually, a "Deposit" and, collectively, the "Deposits") and (ii) credit
each Deposit to the related Account as set forth therein. No amount shall be
deposited in any Account other than the related Deposit.

                                       2
<PAGE>   4
                                                   [Deposit Agreement (Class B)]

         SECTION 1.4 Interest. (a) Each Deposit shall bear interest from and
including the date of deposit to but excluding the date of withdrawal at the
rate of 7.12% per annum (computed on the basis of a year of twelve 30-day
months) payable to the Paying Agent on behalf of the Escrow Agent semi-annually
in arrears on each January 2 and July 2 commencing on January 2, 1999 (each, an
"Interest Payment Date") and, as provided in Section 2.3(b) hereof, on the date
of the Final Withdrawal (as defined below), all in accordance with the terms of
this Agreement (whether or not any such Deposit is withdrawn on an Interest
Payment Date). Interest accrued on any Deposit that is withdrawn pursuant to a
Notice of Purchase Withdrawal (as defined below) shall be paid on the next
Interest Payment Date, notwithstanding any intervening Final Withdrawal (as
defined below) of all of the remaining Deposits (any such Deposits consisting of
unpaid interest only and remaining after a Final Withdrawal may be referred to
as the "Carryover Deposits").

                  (b) The parties hereto further acknowledge and agree that upon
any increase in the rate of interest on the Certificates (such increase referred
to as a "Rate Increase") pursuant to the terms of the Registration Rights
Agreement, the rate of interest borne by each Deposit in accordance with Section
2.2(a) above shall increase by the amount of such Rate Increase, and upon any
subsequent decrease in the rate of interest on the Equipment Notes (such
decrease referred to as a "Rate Decrease") pursuant to the terms of the
Registration Rights Agreement, the rate of interest borne by such Deposit shall
decrease by the amount of such Rate Decrease. For the purposes of this Section
2.2(b), "Registration Rights Agreement" means the Exchange and Registration
Rights Agreement dated the date hereof among America West, the Pass Through
Trustee, certain other pass through trustees and the Initial Purchasers.

         SECTION 1.5 Withdrawals. (a) On and after the date seven days after the
establishment of any Deposit, the Escrow Agent may, by providing at least one
Business Day's prior notice of withdrawal to the Depositary in the form of
Exhibit A hereto (a "Notice of Purchase Withdrawal"), withdraw not less than the
entire principal balance of such Deposit, except that at any time prior to the
actual withdrawal of such Deposit, the Escrow Agent or the Pass Through Trustee
may, by notice to the Depositary, cancel such withdrawal (including on the
scheduled date therefor), and thereafter such Deposit shall continue to be
maintained by the Depositary in accordance with the original terms thereof.
Following such withdrawal the balance in the related Account shall be zero and
the Depositary shall, subject to the Depositary's payment obligation pursuant to
the last sentence of Section 2.2(a) hereof, close such Account. As used herein,
"Business Day" means any day, other than a Saturday, Sunday or other day on
which commercial banks are authorized or required by law to close in New York,
New York, Chicago, Illinois, Phoenix, Arizona, Hartford, Connecticut or
Wilmington, Delaware.

                  (b) The Escrow Agent may, subject to Section 1.02(d) of the
Escrow and Paying Agent Agreement, by providing at least 15 days' prior notice
of withdrawal to the

                                       3
<PAGE>   5
                                                   [Deposit Agreement (Class B)]

Depositary in the form of Exhibit B hereto (a "Notice of Final Withdrawal"),
withdraw the entire amount of all of the remaining Deposits together with the
payment by the Depositary of all accrued and unpaid interest on such Deposits to
but excluding the specified date of withdrawal (a "Final Withdrawal"), on such
date as shall be specified in such Notice of Final Withdrawal. If a Notice of
Final Withdrawal has not been given to the Depositary on or before February 7,
2000 and there are unwithdrawn Deposits on such date, the Depositary shall pay
the amount of the Final Withdrawal to the Paying Agent on February 28, 2000.

                  (c) If the Depositary receives a duly completed Notice of
Purchase Withdrawal or Notice of Final Withdrawal (each, a "Withdrawal Notice")
complying with the provisions of this Agreement, it shall make the payments
specified therein in accordance with the provisions of this Agreement. If such
complying Withdrawal Notice is received by the Depositary no later than 3:00
p.m. on a Business Day, the Depositary shall make the payments requested in such
Withdrawal Notice no later than 11:00 a.m. on the next succeeding Business Day
or such later day specified in such Withdrawal Notice, and if such complying
Withdrawal Notice is received by the Depositary after 3:00 p.m. on a Business
Day, the Depositary shall make the payments requested in such Withdrawal Notice
no later than 11:00 a.m. on the second Business Day next following such Business
Day.

         SECTION 1.6 Other Accounts. On the date of withdrawal of any Deposit,
the Escrow Agent, or the Pass Through Trustee on behalf of the Escrow Agent,
shall be entitled to re-deposit with the Depositary any portion thereof and the
Depositary shall accept the same for deposit hereunder. Any sums so received for
deposit shall be established as a new Deposit and credited to a new Account, all
as more fully provided in Section 2.1 hereof, and thereafter the provisions of
this Agreement shall apply thereto as fully and with the same force and effect
as if such Deposit had been established on the Deposit Date except that (i) such
Deposit may not be withdrawn prior to the date seven days after the
establishment thereof and (ii) such Deposit shall mature on February 28, 2000
and bear interest as provided in Section 2.2. The Depositary shall promptly give
notice to the Escrow Agent of receipt of each such re-deposit and the account
number assigned thereto.

         SECTION 2. Termination. This Agreement shall terminate on the fifth
Business Day after the later of the date on which (i) all of the Deposits shall
have been withdrawn and paid as provided herein without any re-deposit and (ii)
all accrued and unpaid interest on the Deposits shall have been paid as provided
herein, but in no event prior to the date on which the Depositary shall have
performed in full its obligations hereunder.

         SECTION 3. Payments. All payments (including, without limitation, those
payments made in respect of Taxes (as defined and provided for below)) made by
the Depositary hereunder shall be paid in United States Dollars and immediately
available funds by wire transfer (i) in the

                                       4
<PAGE>   6
                                                   [Deposit Agreement (Class b)]

case of accrued interest on the Deposits payable under Section 2.2 hereof or any
Final Withdrawal, directly to the Paying Agent at Wilmington Trust Company,
Wilmington, Delaware, ABA# 031-100-092, for credit to the account of America
West 1998-1 (Subordination Account), Account No. 46427-1, Attention: Rosemary
Pantano, Telephone No. (302) 427-4805, Reference: America West 1998-1B, or to
such other account as the Paying Agent may direct from time to time in writing
to the Depositary and the Escrow Agent and (ii) in the case of any withdrawal of
one or more Deposits pursuant to a Notice of Purchase Withdrawal, directly to or
as directed by the Pass Through Trustee as specified and in the manner provided
in such Notice of Purchase Withdrawal. The Depositary hereby waives any and all
rights of set-off, combination of accounts, right of retention or similar right
(whether arising under applicable law, contract or otherwise) it may have
against the Deposits howsoever arising. All payments on or in respect of each
Deposit shall be made free and clear of and without reduction for or on account
of any and all taxes, levies or other impositions or charges (collectively,
"Taxes"). However, if the Depositary or the Paying Agent (pursuant to Section
2.04 of the Escrow and Paying Agent Agreement) shall be required by law to
deduct or withhold any Taxes from or in respect of any sum payable hereunder,
the Depositary shall (i) make such deductions or withholding, (ii) pay the full
amount deducted or withheld (including in respect of such additional amounts) to
the competent taxation authority and (iii) if the Taxes required to be deducted
or withheld are imposed by the Netherlands or any political subdivision thereof,
pay such additional amounts as may be necessary in order that the actual amount
received by the designated recipient of such sum under this Agreement or the
Escrow and Paying Agent Agreement after such deduction or withholding equals the
sum it would have received had no such deduction or withholding been required.
If the date on which any payment due on any Deposit would otherwise fall on a
day which is not a Business Day, such payment shall be made on the next
succeeding Business Day, and no additional interest shall accrue in respect of
such extension.

         SECTION 4. Representation and Warranties. The Depositary hereby
represents and warrants to America West, the Escrow Agent, the Pass Through
Trustee, the Initial Purchasers and the Paying Agent that:

                  (1) it is a bank duly organized and validly existing in good
standing under the laws of its jurisdiction of organization and is duly
qualified to conduct banking business in the State of Illinois through its
Chicago branch;

                  (2) it has full power, authority and legal right to conduct
its business and operations as currently conducted and to enter into and perform
its obligations under this Agreement;

                  (3) the execution, delivery and performance of this Agreement
have been duly authorized by all necessary corporate action on the part of it
and do not require any stockholder

                                       5
<PAGE>   7
                                                   [Deposit Agreement (Class B)]

approval, or approval or consent of any trustee or holder of any indebtedness or
obligations of it, and such document has been duly executed and delivered by it
and constitutes its legal, valid and binding obligations enforceable against it
in accordance with the terms hereof;

                  (4) no authorization, consent or approval of or other action
by, and no notice to or filing with, any United States federal or state
governmental authority or regulatory body is required for the execution,
delivery or performance by it of this Agreement;

                  (5) neither the execution, delivery or performance by it of
this Agreement, nor compliance with the terms and provisions hereof, conflicts
or will conflict with or results or will result in a breach or violation of any
of the terms, conditions or provisions of, or will require any consent or
approval under, any law, governmental rule or regulation or the charter
documents, as amended, or bylaws, as amended, of it or any similar instrument
binding on it or any order, writ, injunction or decree of any court or
governmental authority against it or by which it or any of its properties is
bound or any indenture, mortgage or contract or other agreement or instrument to
which it is a party or by which it or any of its properties is bound, or
constitutes or will constitute a default thereunder or results or will result in
the imposition of any lien upon any of its properties; and

                  (6) there are no pending or, to its knowledge, threatened
actions, suits, investigations or proceedings (whether or not purportedly on
behalf of it) against or affecting it or any of its property before or by any
court or administrative agency which, if adversely determined, (i) would
adversely affect the ability of it to perform its obligations under this
Agreement or (ii) would call into question or challenge the validity of this
Agreement or the enforceability hereof in accordance with the terms hereof, nor
is the Depositary in default with respect to any order of any court,
governmental authority, arbitration board or administrative agency so as to
adversely affect its ability to perform its obligations under this Agreement.

         SECTION 5. Transfer. Neither party hereto shall be entitled to assign
or otherwise transfer this Agreement (or any interest herein) other than (in the
case of the Escrow Agent) to a successor escrow agent under the Escrow and
Paying Agent Agreement, and any purported assignment in violation thereof shall
be void. This Agreement shall be binding upon the parties hereto and their
respective successors and (in the case of the Escrow Agent) permitted assigns.
Upon the occurrence of the Transfer (as defined below) contemplated by the
Assignment and Assumption Agreement (as defined below), the Pass Through Trustee
shall (without further act) be deemed to have transferred all of its right,
title and interest in and to this Agreement to the trustee of the Successor
Trust (as defined below) and, thereafter, the trustee of the Successor Trust
shall be deemed to be the "Pass Through Trustee" hereunder with the rights of
the "Pass Through Trustee" hereunder, and each reference herein to "America West
Airlines Pass Through Trust 1998-1B-O" shall be deemed to be a reference to
"America West Airlines Pass Through 

                                       6
<PAGE>   8
                                                   [Deposit Agreement (Class B)]

Trust 1998-1B-S". The Escrow Agent and the Depositary hereby acknowledge and
consent to the Transfer contemplated by the Assignment and Assumption Agreement.
For the purposes of this Section 6, "Transfer" means the transfer contemplated
by the Assignment and Assumption Agreement; "Assignment and Assumption
Agreement" means the Assignment and Assumption Agreement to be entered into
between the Pass Through Trustee and the trustee of the Successor Trust,
substantially in the form of Exhibit D to the Pass Through Trust Agreement; and
"Successor Trust" means the America West Airlines Pass Through Trust 1998-1B-S.

         SECTION 6. Amendment, Etc. This Agreement may not be amended, waived or
otherwise modified except by an instrument in writing signed by the party
against whom the amendment, waiver or other modification is sought to be
enforced and by the Pass Through Trustee.

         SECTION 7. Notices. Unless otherwise expressly provided herein, any
notice or other communication under this Agreement shall be in writing
(including by facsimile) and shall be deemed to be given and effective upon
receipt thereof (or, if received after normal business hours, the next open of
business on a Business Day). All notices shall be sent to (x) in the case of the
Depositary, ABN AMRO BANK N.V., 135 South LaSalle Street, Chicago, Illinois
60603, Attention: Vice President - Aerospace (Telecopier: 312-606-8428), with a
copy to ABN AMRO Bank N.V., Chicago Branch, 181 W. Madison Street, Chicago,
Illinois 60602, Attention: Money Market Desk (Telecopier: 312-904-9106) or (y)
in the case of the Escrow Agent, Wilmington Trust Company, 1100 North Market
Street, Wilmington, Delaware 19890, Attention: Corporate Trust Administration
(Telecopier: (302) 651-8882), in each case, with a copy to the Pass Through
Trustee, Wilmington Trust Company, 1100 North Market Street, Wilmington,
Delaware 19890, Attention: Corporate Trust Administration (Telecopier: (302)
651-8882) and to America West, America West Airlines, Inc., 4000 East Sky Harbor
Boulevard, Phoenix, Arizona 95043, Attention: Senior Vice President-Legal
Affairs (Telecopier: (602) 693-5904) (or at such other address as any such party
may specify from time to time in a written notice to the parties hereto). On or
prior to the execution of this Agreement, the Escrow Agent has delivered to the
Depositary a certificate containing specimen signatures of the representatives
of the Escrow Agent who are authorized to give notices and instructions with
respect to this Agreement. The Depositary may conclusively rely on such
certificate until the Depositary receives written notice from the Escrow Agent
to the contrary.

         SECTION 8. Obligations Unconditional. The Depositary hereby
acknowledges and agrees that its obligation to repay each Deposit together with
interest thereon as provided herein is absolute, irrevocable and unconditional
and constitutes a full recourse obligation of the Depositary enforceable against
it to the full extent of all of its assets and properties.

                                       7
<PAGE>   9
                                                   [Deposit Agreement (Class B)]

         SECTION 9. Entire Agreement. This Agreement (including all attachments
hereto) sets forth all of the promises, covenants, agreements, conditions and
understandings between the Depositary and the Escrow Agent with respect to the
subject matter hereof and supersedes all prior and contemporaneous agreements
and undertakings, inducements or conditions, express or implied, oral or
written.

         SECTION 10. Governing Law. This Agreement, and the rights and
obligations of the Depositary and the Escrow Agent with respect to the Deposits,
shall be governed by, and construed in accordance with, the law of the State of
New York.

         SECTION 11. Waiver of Jury Trial Right. EACH OF THE DEPOSITARY AND THE
ESCROW AGENT ACKNOWLEDGES AND ACCEPTS THAT IN ANY SUIT, ACTION OR PROCEEDING
ARISING OUT OF OR RELATING TO THIS AGREEMENT SUCH PARTY IRREVOCABLY WAIVES ITS
RIGHT TO A TRIAL BY JURY.

         SECTION 12. Counterparts. This Agreement may be executed in one or more
counterparts, all of which taken together shall constitute one instrument.

         SECTION 13. Head Office Obligation. ABN AMRO Bank N.V. hereby agrees
that the obligations of the Depositary hereunder are also the obligations of ABN
AMRO Bank N.V.'s Head Office in the Netherlands. Accordingly, any beneficiary of
this Agreement will be able to proceed directly against ABN AMRO Bank N.V.'s
Head Office in the Netherlands if ABN AMRO Bank N.V.'s Chicago branch defaults
in its obligation to such beneficiary under this Agreement.


                                      * * *

                                       8
<PAGE>   10
                                                   [Deposit Agreement (Class B)]

                  IN WITNESS WHEREOF, the Escrow Agent and the Depositary have
caused this Deposit Agreement to be duly executed as of the day and year first
above written.



                                       WILMINGTON TRUST COMPANY,
                                          as Escrow Agent


                                       By:       /s/ Norma P. Closs
                                          -------------------------------------
                                          Name:  Norma P. Closs
                                          Title: Vice President



                                       ABN AMRO BANK N.V., CHICAGO BRANCH, 
                                       as Depositary



                                       By:       /s/ Claudia C. Heldring
                                          -------------------------------------
                                          Name:  Claudia C. Heldring
                                          Title: Vice President



                                       By:       /s/ Carla S. Waggoner
                                          -------------------------------------
                                          Name:  Carla S. Waggoner
                                          Title: Assistant Vice President

                                       9
<PAGE>   11
                                                   [Deposit Agreement (Class B)]

                                   Schedule I

                              Schedule of Deposits
                                    (Class B)


<TABLE>
<CAPTION>
Date              Deposit Amount            Account No.             Maturity Date
- ----              --------------            -----------             -------------
<S>               <C>                       <C>                     <C>
11/1/98              4,880,363                D157562                  2/28/00
12/1/98              4,920,373                D157554                  2/28/00
12/1/98              4,920,373                D157555                  2/28/00
 2/1/98              6,098,551                D157556                  2/28/00
 5/1/99              6,100,267                D157546                  2/28/00
 7/1/99              4,731,000                D157541                  2/28/00
 7/1/99              4,731,000                D157542                  2/28/00
 8/1/99              4,772,073                D157536                  2/28/00
                     ---------
                    41,154,000
</TABLE>
<PAGE>   12
                                                   [Deposit Agreement (Class B)]

                                    EXHIBIT A

                          NOTICE OF PURCHASE WITHDRAWAL



ABN AMRO BANK N.V.
135 South LaSalle Street
Chicago, Illinois  60603
Attention: Lukas van der Hoef
Telecopier: (312) 606-8428

Gentlemen:

         Reference is made to the Deposit Agreement (Class B) dated as of
____________, 1998 (the "Deposit Agreement") between Wilmington Trust Company,
as Escrow Agent, and ABN AMRO Bank N.V., Chicago Branch, as Depositary (the
"Depositary").

         In accordance with Section 2.3(a) of the Deposit Agreement, the
undersigned hereby requests the withdrawal of the entire amount of the Deposit,
$_______, Account No. ____________.

         The undersigned hereby directs the Depositary to pay the proceeds of
the Deposit to [________________, Account No. _____, Reference: _________] on
_________ __, 199_, upon the telephonic request of a representative of the Pass
Through Trustee.


                                       WILMINGTON TRUST COMPANY,
                                       as Escrow Agent



                                       By:
                                          -------------------------------------
                                          Name:
                                               --------------------------------
                                          Title:
                                                -------------------------------


Dated:          , 199
      ----------     ----
<PAGE>   13
                                                   [Deposit Agreement (Class B)]

                                    EXHIBIT B

                           NOTICE OF FINAL WITHDRAWAL



ABN AMRO BANK N.V.
135 South LaSalle Street
Chicago, Illinois  60603
Attention: Lukas van der Hoef
Telecopier: (312) 606-8428

Gentlemen:

         Reference is made to the Deposit Agreement (Class B) dated as of
______________, 1998 (the "Deposit Agreement") between Wilmington Trust Company,
as Escrow Agent, and ABN AMRO Bank N.V., Chicago Branch, as Depositary (the
"Depositary").

         In accordance with Section 2.3(b) of the Deposit Agreement, the
undersigned hereby requests the withdrawal of the entire amount of all Deposits
for payment on _______________, 199__.

         The undersigned hereby directs the Depositary to pay the proceeds of
the Deposits and accrued interest thereon to the Paying Agent at
__________________________, ABA# _____________, Account No. _____________,
Reference: America West 1998-1.


                                       WILMINGTON TRUST COMPANY,
                                       as Escrow Agent



                                       By:
                                          -------------------------------------
                                          Name:
                                               --------------------------------
                                          Title:
                                                -------------------------------

Dated:          , 199
      ----------     ----
<PAGE>   14
                                                   [Deposit Agreement (Class B)]




<TABLE>
<CAPTION>
  Date                         Deposit Amount                       Account No.                    Maturity Date
  ----                         --------------                       -----------                    -------------
<S>                            <C>                                  <C>                            <C>
11/1/98                           4,880,363                                                           3/01/00
12/1/98                           4,920,373                                                           3/01/00
12/1/98                           4,920,373                                                           3/01/00
 2/1/99                           6,098,551                                                           3/01/00
 5/1/99                           6,100,267                                                           3/01/00
 7/1/99                           4,731,000                                                           3/01/00
 7/1/99                           4,731,000                                                           3/01/00
 8/1/99                           4,772,073                                                           3/01/00
                                  ---------
                                 41,154,000
                                 ==========
</TABLE>

<PAGE>   1
                                                                    EXHIBIT 4.17


                                DEPOSIT AGREEMENT
                                    (Class C)

                           Dated as of October 6, 1998

                                     between

                            WILMINGTON TRUST COMPANY

                                 as Escrow Agent

                                       and

                               ABN AMRO BANK N.V.,
                                 Chicago Branch

                                  as Depositary

<PAGE>   2

         DEPOSIT AGREEMENT (Class C) dated as of October 6, 1998 (as amended,
modified or supplemented from time to time, this "Agreement") between WILMINGTON
TRUST COMPANY, a Delaware banking corporation, as Escrow Agent under the Escrow
and Paying Agent Agreement referred to below (in such capacity, together with
its successors in such capacity, the "Escrow Agent"), and ABN AMRO BANK N.V., a
bank organized under the laws of the Netherlands, acting through its Chicago
branch, as depositary bank (the "Depositary").

                               W I T N E S S E T H

         WHEREAS, America West Airlines, Inc. ("America West") and Wilmington
Trust Company, not in its individual capacity except as otherwise expressly
provided therein, but solely as trustee (in such capacity, together with its
successors in such capacity, the "Pass Through Trustee") have entered into a
Pass Through Trust Agreement dated as of October 6, 1998 (as amended, modified
or supplemented from time to time in accordance with the terms thereof, the
"Pass Through Trust Agreement") relating to America West Airlines Pass Through
Trust 1998-1C-O pursuant to which the America West Airlines Pass Through Trust,
Series 1998-1C-O Certificates referred to therein (the "Certificates") are being
issued;

         WHEREAS, America West and Morgan Stanley & Co. Incorporated, Donaldson,
Lufkin & Jenrette Securities Corporation, Merrill Lynch, Pierce, Fenner & Smith
Incorporated and Salomon Smith Barney Inc. (collectively, the "Initial
Purchasers" and, together with their respective transferees and assigns as
registered owners of the Certificates, the "Investors") have entered into a
Purchase Agreement dated as of October 6, 1998 pursuant to which the Pass
Through Trustee will issue and sell the Certificates to the Initial Purchasers
(the net proceeds of such sale being herein referred to as the "Net Proceeds");

         WHEREAS, America West, the Pass Through Trustee, certain other pass
through trustees and certain other persons concurrently herewith are entering
into the Note Purchase Agreement, dated as of the date hereof (the "Note
Purchase Agreement"), pursuant to which the Pass Through Trustee has agreed to
acquire from time to time on or prior to the Delivery Period Termination Date
(as defined in the Note Purchase Agreement) equipment notes (the "Equipment
Notes") issued to finance or refinance the acquisition of aircraft by America
West, as lessee or as owner, utilizing a portion of the Net Proceeds;

         WHEREAS, the Escrow Agent, the Initial Purchasers, the Pass Through
Trustee and Wilmington Trust Company, as paying agent for the Escrow Agent (in
such capacity, together with its successors in such capacity, the "Paying
Agent") concurrently herewith are entering into an Escrow and Paying Agent
Agreement, dated as of the date hereof (as amended, modified or supplemented
from time to time in accordance with the terms thereof, the "Escrow and Paying
Agent Agreement"); and

<PAGE>   3

                                                   [Deposit Agreement (Class C)]

         WHEREAS, the Initial Purchasers and the Pass Through Trustee intend
that the Net Proceeds be held in escrow by the Escrow Agent on behalf of the
Investors pursuant to the Escrow and Paying Agent Agreement, subject to
withdrawal upon request of and proper certification by the Pass Through Trustee
for the purpose of purchasing Equipment Notes, and that pending such withdrawal
the Net Proceeds be deposited by the Escrow Agent with the Depositary pursuant
to this Agreement, which provides for the Depositary to pay interest for
distribution to the Investors and to establish accounts from which the Escrow
Agent shall make withdrawals upon request of and proper certification by the
Pass Through Trustee.

         NOW, THEREFORE, in consideration of the obligations contained herein,
and for other good and valuable consideration, the receipt and sufficiency of
which is hereby acknowledged, the parties hereto hereby agree as follows:

         SECTION 1.1 Acceptance of Depositary. The Depositary hereby agrees to
act as depositary bank as provided herein and in connection therewith to accept
all amounts to be delivered to or held by the Depositary pursuant to the terms
of this Agreement. The Depositary further agrees to hold, maintain and safeguard
the Deposits and the Accounts (as defined below) during the term of this
Agreement in accordance with the provisions of this Agreement. The Escrow Agent
shall not have any right to withdraw, assign or otherwise transfer moneys held
in the Accounts except as permitted by this Agreement.

         SECTION 1.2 Establishment of Accounts. The Escrow Agent hereby
instructs the Depositary, and the Depositary agrees, to establish the separate
deposit accounts listed on Schedule I hereto and to establish such additional
separate deposit accounts as may be required in connection with the deposits
contemplated by Section 2.4 hereof (each, an "Account" and collectively, the
"Accounts"), each in the name of the Escrow Agent and all on the terms and
conditions set forth in this Agreement.

         SECTION 1.3 Deposits. The Escrow Agent shall direct the Initial
Purchasers to deposit with the Depositary on the date of this Agreement (the
"Deposit Date") in Federal (same day) funds by wire transfer to: Federal Reserve
Bank, New York, ABN NY ABA #026009580, Account: Chicago Treasury, Reference:
America West Deposit, and the Depositary shall accept from the Initial
Purchasers, on behalf of the Escrow Agent, the sum of US$17,705,000.00. Upon
acceptance of such sum, the Depositary shall (i) establish each of the deposits
specified in Schedule I hereto maturing on the respective dates set forth
therein (including any deposit made pursuant to Section 2.4 hereof,
individually, a "Deposit" and, collectively, the "Deposits") and (ii) credit
each Deposit to the related Account as set forth therein. No amount shall be
deposited in any Account other than the related Deposit.


                                       2
<PAGE>   4

                                                   [Deposit Agreement (Class C)]

         SECTION 1.4 Interest. (a) Each Deposit shall bear interest from and
including the date of deposit to but excluding the date of withdrawal at the
rate of 7.84% per annum (computed on the basis of a year of twelve 30-day
months) payable to the Paying Agent on behalf of the Escrow Agent semi-annually
in arrears on each January 2 and July 2 commencing on January 2, 1999 (each, an
"Interest Payment Date") and, as provided in Section 2.3(b) hereof, on the date
of the Final Withdrawal (as defined below), all in accordance with the terms of
this Agreement (whether or not any such Deposit is withdrawn on an Interest
Payment Date). Interest accrued on any Deposit that is withdrawn pursuant to a
Notice of Purchase Withdrawal (as defined below) shall be paid on the next
Interest Payment Date, notwithstanding any intervening Final Withdrawal (as
defined below) of all of the remaining Deposits (any such Deposits consisting of
unpaid interest only and remaining after a Final Withdrawal may be referred to
as the "Carryover Deposits").

                  (b) The parties hereto further acknowledge and agree that upon
any increase in the rate of interest on the Certificates (such increase referred
to as a "Rate Increase") pursuant to the terms of the Registration Rights
Agreement, the rate of interest borne by each Deposit in accordance with Section
2.2(a) above shall increase by the amount of such Rate Increase, and upon any
subsequent decrease in the rate of interest on the Equipment Notes (such
decrease referred to as a "Rate Decrease") pursuant to the terms of the
Registration Rights Agreement, the rate of interest borne by such Deposit shall
decrease by the amount of such Rate Decrease. For the purposes of this Section
2.2(b), "Registration Rights Agreement" means the Exchange and Registration
Rights Agreement dated the date hereof among America West, the Pass Through
Trustee, certain other pass through trustees and the Initial Purchasers.

         SECTION 1.5 Withdrawals. (a) On and after the date seven days after the
establishment of any Deposit, the Escrow Agent may, by providing at least one
Business Day's prior notice of withdrawal to the Depositary in the form of
Exhibit A hereto (a "Notice of Purchase Withdrawal"), withdraw not less than the
entire principal balance of such Deposit, except that at any time prior to the
actual withdrawal of such Deposit, the Escrow Agent or the Pass Through Trustee
may, by notice to the Depositary, cancel such withdrawal (including on the
scheduled date therefor), and thereafter such Deposit shall continue to be
maintained by the Depositary in accordance with the original terms thereof.
Following such withdrawal the balance in the related Account shall be zero and
the Depositary shall, subject to the Depositary's payment obligation pursuant to
the last sentence of Section 2.2(a) hereof, close such Account. As used herein,
"Business Day" means any day, other than a Saturday, Sunday or other day on
which commercial banks are authorized or required by law to close in New York,
New York, Chicago, Illinois, Phoenix, Arizona, Hartford, Connecticut or
Wilmington, Delaware.

                  (b) The Escrow Agent may, subject to Section 1.02(d) of the
Escrow and Paying Agent Agreement, by providing at least 15 days' prior notice
of withdrawal to the


                                       3
<PAGE>   5

                                                   [Deposit Agreement (Class C)]

Depositary in the form of Exhibit B hereto (a "Notice of Final Withdrawal"),
withdraw the entire amount of all of the remaining Deposits together with the
payment by the Depositary of all accrued and unpaid interest on such Deposits to
but excluding the specified date of withdrawal (a "Final Withdrawal"), on such
date as shall be specified in such Notice of Final Withdrawal. If a Notice of
Final Withdrawal has not been given to the Depositary on or before February 7,
2000 and there are unwithdrawn Deposits on such date, the Depositary shall pay
the amount of the Final Withdrawal to the Paying Agent on February 28, 2000.

                  (c) If the Depositary receives a duly completed Notice of
Purchase Withdrawal or Notice of Final Withdrawal (each, a "Withdrawal Notice")
complying with the provisions of this Agreement, it shall make the payments
specified therein in accordance with the provisions of this Agreement. If such
complying Withdrawal Notice is received by the Depositary no later than 3:00
p.m. on a Business Day, the Depositary shall make the payments requested in such
Withdrawal Notice no later than 11:00 a.m. on the next succeeding Business Day
or such later day specified in such Withdrawal Notice, and if such complying
Withdrawal Notice is received by the Depositary after 3:00 p.m. on a Business
Day, the Depositary shall make the payments requested in such Withdrawal Notice
no later than 11:00 a.m. on the second Business Day next following such Business
Day.

         SECTION 1.6 Other Accounts. On the date of withdrawal of any Deposit,
the Escrow Agent, or the Pass Through Trustee on behalf of the Escrow Agent,
shall be entitled to re-deposit with the Depositary any portion thereof and the
Depositary shall accept the same for deposit hereunder. Any sums so received for
deposit shall be established as a new Deposit and credited to a new Account, all
as more fully provided in Section 2.1 hereof, and thereafter the provisions of
this Agreement shall apply thereto as fully and with the same force and effect
as if such Deposit had been established on the Deposit Date except that (i) such
Deposit may not be withdrawn prior to the date seven days after the
establishment thereof and (ii) such Deposit shall mature on February 28, 2000
and bear interest as provided in Section 2.2. The Depositary shall promptly give
notice to the Escrow Agent of receipt of each such re-deposit and the account
number assigned thereto.

         SECTION 2. Termination. This Agreement shall terminate on the fifth
Business Day after the later of the date on which (i) all of the Deposits shall
have been withdrawn and paid as provided herein without any re-deposit and (ii)
all accrued and unpaid interest on the Deposits shall have been paid as provided
herein, but in no event prior to the date on which the Depositary shall have
performed in full its obligations hereunder.

         SECTION 3. Payments. All payments (including, without limitation, those
payments made in respect of Taxes (as defined and provided for below)) made by
the Depositary hereunder shall be paid in United States Dollars and immediately
available funds by wire transfer (i) in the


                                       4
<PAGE>   6

                                                   [Deposit Agreement (Class C)]

case of accrued interest on the Deposits payable under Section 2.2 hereof or any
Final Withdrawal, directly to the Paying Agent at Wilmington Trust Company,
Wilmington, Delaware, ABA# 031-100-092, for credit to the account of America
West 1998-1 (Subordination Account), Account No. 46427-1, Attention: Rosemary
Pantano, Telephone No. (302) 427-4805, Reference: America West 1998-1C, or to
such other account as the Paying Agent may direct from time to time in writing
to the Depositary and the Escrow Agent and (ii) in the case of any withdrawal of
one or more Deposits pursuant to a Notice of Purchase Withdrawal, directly to or
as directed by the Pass Through Trustee as specified and in the manner provided
in such Notice of Purchase Withdrawal. The Depositary hereby waives any and all
rights of set-off, combination of accounts, right of retention or similar right
(whether arising under applicable law, contract or otherwise) it may have
against the Deposits howsoever arising. All payments on or in respect of each
Deposit shall be made free and clear of and without reduction for or on account
of any and all taxes, levies or other impositions or charges (collectively,
"Taxes"). However, if the Depositary or the Paying Agent (pursuant to Section
2.04 of the Escrow and Paying Agent Agreement) shall be required by law to
deduct or withhold any Taxes from or in respect of any sum payable hereunder,
the Depositary shall (i) make such deductions or withholding, (ii) pay the full
amount deducted or withheld (including in respect of such additional amounts) to
the competent taxation authority and (iii) if the Taxes required to be deducted
or withheld are imposed by the Netherlands or any political subdivision thereof,
pay such additional amounts as may be necessary in order that the actual amount
received by the designated recipient of such sum under this Agreement or the
Escrow and Paying Agent Agreement after such deduction or withholding equals the
sum it would have received had no such deduction or withholding been required.
If the date on which any payment due on any Deposit would otherwise fall on a
day which is not a Business Day, such payment shall be made on the next
succeeding Business Day, and no additional interest shall accrue in respect of
such extension.

         SECTION 4. Representation and Warranties. The Depositary hereby
represents and warrants to America West, the Escrow Agent, the Pass Through
Trustee, the Initial Purchasers and the Paying Agent that:

                  (1) it is a bank duly organized and validly existing in good
standing under the laws of its jurisdiction of organization and is duly
qualified to conduct banking business in the State of Illinois through its
Chicago branch;

                  (2) it has full power, authority and legal right to conduct
its business and operations as currently conducted and to enter into and perform
its obligations under this Agreement;

                  (3) the execution, delivery and performance of this Agreement
have been duly authorized by all necessary corporate action on the part of it
and do not require any stockholder


                                       5
<PAGE>   7

                                                   [Deposit Agreement (Class C)]

approval, or approval or consent of any trustee or holder of any indebtedness or
obligations of it, and such document has been duly executed and delivered by it
and constitutes its legal, valid and binding obligations enforceable against it
in accordance with the terms hereof;

                  (4) no authorization, consent or approval of or other action
by, and no notice to or filing with, any United States federal or state
governmental authority or regulatory body is required for the execution,
delivery or performance by it of this Agreement;

                  (5) neither the execution, delivery or performance by it of
this Agreement, nor compliance with the terms and provisions hereof, conflicts
or will conflict with or results or will result in a breach or violation of any
of the terms, conditions or provisions of, or will require any consent or
approval under, any law, governmental rule or regulation or the charter
documents, as amended, or bylaws, as amended, of it or any similar instrument
binding on it or any order, writ, injunction or decree of any court or
governmental authority against it or by which it or any of its properties is
bound or any indenture, mortgage or contract or other agreement or instrument to
which it is a party or by which it or any of its properties is bound, or
constitutes or will constitute a default thereunder or results or will result in
the imposition of any lien upon any of its properties; and

                  (6) there are no pending or, to its knowledge, threatened
actions, suits, investigations or proceedings (whether or not purportedly on
behalf of it) against or affecting it or any of its property before or by any
court or administrative agency which, if adversely determined, (i) would
adversely affect the ability of it to perform its obligations under this
Agreement or (ii) would call into question or challenge the validity of this
Agreement or the enforceability hereof in accordance with the terms hereof, nor
is the Depositary in default with respect to any order of any court,
governmental authority, arbitration board or administrative agency so as to
adversely affect its ability to perform its obligations under this Agreement.

         SECTION 5. Transfer. Neither party hereto shall be entitled to assign
or otherwise transfer this Agreement (or any interest herein) other than (in the
case of the Escrow Agent) to a successor escrow agent under the Escrow and
Paying Agent Agreement, and any purported assignment in violation thereof shall
be void. This Agreement shall be binding upon the parties hereto and their
respective successors and (in the case of the Escrow Agent) permitted assigns.
Upon the occurrence of the Transfer (as defined below) contemplated by the
Assignment and Assumption Agreement (as defined below), the Pass Through Trustee
shall (without further act) be deemed to have transferred all of its right,
title and interest in and to this Agreement to the trustee of the Successor
Trust (as defined below) and, thereafter, the trustee of the Successor Trust
shall be deemed to be the "Pass Through Trustee" hereunder with the rights of
the "Pass Through Trustee" hereunder, and each reference herein to "America West
Airlines Pass Through Trust 1998-1C-O" shall be deemed to be a reference to
"America West Airlines Pass Through


                                       6
<PAGE>   8

                                                   [Deposit Agreement (Class C)]

Trust 1998-1C-S". The Escrow Agent and the Depositary hereby acknowledge and
consent to the Transfer contemplated by the Assignment and Assumption Agreement.
For the purposes of this Section 6, "Transfer" means the transfer contemplated
by the Assignment and Assumption Agreement; "Assignment and Assumption
Agreement" means the Assignment and Assumption Agreement to be entered into
between the Pass Through Trustee and the trustee of the Successor Trust,
substantially in the form of Exhibit D to the Pass Through Trust Agreement; and
"Successor Trust" means the America West Airlines Pass Through Trust 1998-1C-S.

         SECTION 6. Amendment, Etc. This Agreement may not be amended, waived or
otherwise modified except by an instrument in writing signed by the party
against whom the amendment, waiver or other modification is sought to be
enforced and by the Pass Through Trustee.

         SECTION 7. Notices. Unless otherwise expressly provided herein, any
notice or other communication under this Agreement shall be in writing
(including by facsimile) and shall be deemed to be given and effective upon
receipt thereof (or, if received after normal business hours, the next open of
business on a Business Day). All notices shall be sent to (x) in the case of the
Depositary, ABN AMRO BANK N.V., 135 South LaSalle Street, Chicago, Illinois
60603, Attention: Vice President - Aerospace (Telecopier: 312-606-8428), with a
copy to ABN AMRO Bank N.V., Chicago Branch, 181 W. Madison Street, Chicago,
Illinois 60602, Attention: Money Market Desk (Telecopier: 312-904-9106) or (y)
in the case of the Escrow Agent, Wilmington Trust Company, 1100 North Market
Street, Wilmington, Delaware 19890, Attention: Corporate Trust Administration
(Telecopier: (302) 651-8882), in each case, with a copy to the Pass Through
Trustee, Wilmington Trust Company, 1100 North Market Street, Wilmington,
Delaware 19890, Attention: Corporate Trust Administration (Telecopier: (302)
651-8882) and to America West, America West Airlines, Inc., 4000 East Sky Harbor
Boulevard, Phoenix, Arizona 95043, Attention: Senior Vice President-Legal
Affairs (Telecopier: (602) 693-5904) (or at such other address as any such party
may specify from time to time in a written notice to the parties hereto). On or
prior to the execution of this Agreement, the Escrow Agent has delivered to the
Depositary a certificate containing specimen signatures of the representatives
of the Escrow Agent who are authorized to give notices and instructions with
respect to this Agreement. The Depositary may conclusively rely on such
certificate until the Depositary receives written notice from the Escrow Agent
to the contrary.

         SECTION 8. Obligations Unconditional. The Depositary hereby
acknowledges and agrees that its obligation to repay each Deposit together with
interest thereon as provided herein is absolute, irrevocable and unconditional
and constitutes a full recourse obligation of the Depositary enforceable against
it to the full extent of all of its assets and properties.


                                       7
<PAGE>   9

                                                   [Deposit Agreement (Class C)]

         SECTION 9. Entire Agreement. This Agreement (including all attachments
hereto) sets forth all of the promises, covenants, agreements, conditions and
understandings between the Depositary and the Escrow Agent with respect to the
subject matter hereof and supersedes all prior and contemporaneous agreements
and undertakings, inducements or conditions, express or implied, oral or
written.

         SECTION 10. Governing Law. This Agreement, and the rights and
obligations of the Depositary and the Escrow Agent with respect to the Deposits,
shall be governed by, and construed in accordance with, the law of the State of
New York.

         SECTION 11. Waiver of Jury Trial Right. EACH OF THE DEPOSITARY AND THE
ESCROW AGENT ACKNOWLEDGES AND ACCEPTS THAT IN ANY SUIT, ACTION OR PROCEEDING
ARISING OUT OF OR RELATING TO THIS AGREEMENT SUCH PARTY IRREVOCABLY WAIVES ITS
RIGHT TO A TRIAL BY JURY.

         SECTION 12. Counterparts. This Agreement may be executed in one or more
counterparts, all of which taken together shall constitute one instrument.

         SECTION 13. Head Office Obligation. ABN AMRO Bank N.V. hereby agrees
that the obligations of the Depositary hereunder are also the obligations of ABN
AMRO Bank N.V.'s Head Office in the Netherlands. Accordingly, any beneficiary of
this Agreement will be able to proceed directly against ABN AMRO Bank N.V.'s
Head Office in the Netherlands if ABN AMRO Bank N.V.'s Chicago branch defaults
in its obligation to such beneficiary under this Agreement.

                                      * * *


                                       8
<PAGE>   10

                                                   [Deposit Agreement (Class C)]

         IN WITNESS WHEREOF, the Escrow Agent and the Depositary have caused
this Deposit Agreement to be duly executed as of the day and year first above
written.

                         WILMINGTON TRUST COMPANY,
                            as Escrow Agent

                         By:       /s/ Norma P. Closs
                            -------------------------------------------------
                            Name:  Norma P. Closs
                            Title: Vice President



                         ABN AMRO BANK N.V., CHICAGO BRANCH, as Depositary

                         By:       /s/ Claudia C. Heldring
                            -------------------------------------------------
                            Name:  Claudia C. Heldring
                            Title: Vice President


                         By:       /s/ Carla S. Waggoner
                            -------------------------------------------------
                            Name:  Carla S. Waggoner
                            Title: Assistant Vice President


                                       9
<PAGE>   11

                                                   [Deposit Agreement (Class C)]

                                   Schedule I

                              Schedule of Deposits
                                    (Class C)

<TABLE>
<CAPTION>
Date              Deposit Amount            Account No.           Maturity Date
- ----              --------------            -----------           -------------
<S>               <C>                       <C>                   <C>
11/1/98              1,883,662               D157561               2/28/00
12/1/98              1,742,215               D157552               2/28/00
12/1/98              1,742,215               D157553               2/28/00
 2/1/99              4,098,508               D157549               2/28/00
 5/1/99              4,590,400               D157545               2/28/00
 7/1/99              1,216,000               D157538               2/28/00
 7/1/99              1,216,000               D157539               2/28/00
 8/1/99              1,216,000               D157564               2/28/00
                     ---------
                   17,705,000
</TABLE>

<PAGE>   12

                                                   [Deposit Agreement (Class C)]

                                    EXHIBIT A

                          NOTICE OF PURCHASE WITHDRAWAL

ABN AMRO BANK N.V.
135 South LaSalle Street
Chicago, Illinois  60603
Attention: Lukas van der Hoef
Telecopier: (312) 606-8428

Gentlemen:

         Reference is made to the Deposit Agreement (Class C) dated as of
____________, 1998 (the "Deposit Agreement") between Wilmington Trust Company,
as Escrow Agent, and ABN AMRO Bank N.V., Chicago Branch, as Depositary (the
"Depositary").

         In accordance with Section 2.3(a) of the Deposit Agreement, the
undersigned hereby requests the withdrawal of the entire amount of the Deposit,
$_______, Account No. ____________.

         The undersigned hereby directs the Depositary to pay the proceeds of
the Deposit to [________________, Account No. _____, Reference: _________] on
_________ __, 199_, upon the telephonic request of a representative of the Pass
Through Trustee.

                         WILMINGTON TRUST COMPANY,
                         as Escrow Agent

                         By:__________________________________________________
                            Name:_____________________________________________
                            Title:____________________________________________

Dated: _________, 199_

<PAGE>   13

                                                   [Deposit Agreement (Class C)]

                                    EXHIBIT B

                           NOTICE OF FINAL WITHDRAWAL

ABN AMRO BANK N.V.
135 South LaSalle Street
Chicago, Illinois  60603
Attention: Lukas van der Hoef
Telecopier: (312) 606-8428

Gentlemen:

         Reference is made to the Deposit Agreement (Class C) dated as of
______________, 1998 (the "Deposit Agreement") between Wilmington Trust Company,
as Escrow Agent, and ABN AMRO Bank N.V., Chicago Branch, as Depositary (the
"Depositary").

         In accordance with Section 2.3(b) of the Deposit Agreement, the
undersigned hereby requests the withdrawal of the entire amount of all Deposits
for payment on _______________, 199__.

         The undersigned hereby directs the Depositary to pay the proceeds of
the Deposits and accrued interest thereon to the Paying Agent at
__________________________, ABA# _____________, Account No. _____________,
Reference: America West 1998-1.

                         WILMINGTON TRUST COMPANY,
                         as Escrow Agent

                         By:__________________________________________________
                            Name:_____________________________________________
                            Title:____________________________________________

Dated: _________, 199_

<PAGE>   14

                                                   [Deposit Agreement (Class C)]

<TABLE>
<CAPTION>
             Date                     Deposit Amount                 Account No.                 Maturity Date
             ----                     --------------                 -----------                 -------------
<S>                                   <C>                            <C>                         <C>
           11/1/98                       1,883,662                                                  2/28/00
           12/1/98                       1,742,215                                                  2/28/00
           12/1/98                       1,742,215                                                  2/28/00
            2/1/99                       4,098,508                                                  2/28/00
            5/1/99                       4,590,400                                                  2/28/00
            7/1/99                       1,216,000                                                  2/28/00
            7/1/99                       1,216,000                                                  2/28/00
            8/1/99                       1,216,000                                                  2/28/00
                                        ----------
                                        17,705,000                                                  2/28/00
                                        ==========
</TABLE>

<PAGE>   1
                                                                    Exhibit 4.18


                                                                       EXECUTION



                        ESCROW AND PAYING AGENT AGREEMENT
                                    (Class A)

                           Dated as of October 6, 1998

                                      among

                            WILMINGTON TRUST COMPANY
                                 as Escrow Agent

                       MORGAN STANLEY & CO. INCORPORATED,
               DONALDSON, LUFKIN & JENRETTE SECURITIES CORPORATION
               MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED
                                       and
                            SALOMON SMITH BARNEY INC.

                              as Initial Purchasers

                            WILMINGTON TRUST COMPANY,
                         not in its individual capacity,
                       but solely as Pass Through Trustee
                              for and on behalf of
               America West Airlines Pass Through Trust 1998-1A-O

                             as Pass Through Trustee

                                       and

                            WILMINGTON TRUST COMPANY

                                 as Paying Agent
<PAGE>   2
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                          Page
                                                                          ----
<S>                                                                       <C>
SECTION 1.    Escrow Agent............................................      2


Section 1.01. Appointment of Escrow Agent.............................      2


Section 1.02. Instruction; Etc........................................      3


Section 1.03. Initial Escrow Amount; Issuance of Escrow
              Receipts................................................      4


Section 1.04. Payments to Receiptholders..............................      5


Section 1.05. Mutilated, Destroyed, Lost or Stolen Escrow Receipt.....      5


Section 1.06. Additional Escrow Amounts...............................      6


Section 1.07. Resignation or Removal of Escrow Agent..................      6


Section 1.08. Persons Deemed Owners...................................      7


Section 1.09. Further Assurances......................................      7


SECTION 2.    Paying Agent............................................      7


Section 2.01. Appointment of Paying Agent.............................      7


Section 2.02. Establishment of Paying Agent Account...................      8


Section 2.03. Payments from Paying Agent Account......................      8


Section 2.04. Withholding Taxes.......................................      9


Section 2.05. Resignation or Removal of Paying Agent..................     11
</TABLE>


                                       i
<PAGE>   3
<TABLE>
<CAPTION>
                                                                          Page
                                                                          ----
<S>                                                                       <C>
Section 2.06. Notice of Final Withdrawal..............................     11


SECTION 3.    Payments................................................     12


SECTION 4.    Other Actions...........................................     12


SECTION 5.    Representations and Warranties of the
              Escrow Agent............................................     12


SECTION 6.    Representations and Warranties of the
              Paying Agent............................................     14


SECTION 7.    Indemnification.........................................     15


SECTION 8.    Amendment, Etc..........................................     16


SECTION 9.    Notices.................................................     16


SECTION 10.   Transfer................................................     17


SECTION 11.   Entire Agreement........................................     18


SECTION 12.   Governing Law...........................................     18


SECTION 13.   Waiver of Jury Trial Right..............................     18


SECTION 14.   Counterparts............................................     18
</TABLE>


Exhibit A     Escrow Receipt

Exhibit B     Withdrawal Certificate


                                       ii
<PAGE>   4
            ESCROW AND PAYING AGENT AGREEMENT (Class A) dated as of October 6,
1998 (as amended, modified or supplemented from time to time, this "Agreement")
among WILMINGTON TRUST COMPANY, a Delaware banking corporation, as Escrow Agent
(in such capacity, together with its successors in such capacity, the "Escrow
Agent"); MORGAN STANLEY & CO. INCORPORATED, DONALDSON, LUFKIN & JENRETTE
SECURITIES CORPORATION, MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED and
SALOMON SMITH BARNEY INC., as Initial Purchasers of the Certificates referred to
below (the "Initial Purchasers" and together with their respective transferees
and assigns as registered owners of the Certificates, the "Investors") under the
Purchase Agreement referred to below; Wilmington Trust Company, a Delaware
banking corporation, not in its individual capacity except as otherwise
expressly provided herein, but solely as trustee (in such capacity, together
with its successors in such capacity, the "Pass Through Trustee") under the Pass
Through Trust Agreement referred to below; and WILMINGTON TRUST COMPANY, a
Delaware banking corporation, as paying agent hereunder (in such capacity,
together with its successors in such capacity, the "Paying Agent").

                               W I T N E S S E T H

            WHEREAS, America West Airlines, Inc. ("America West") and the Pass
Through Trustee have entered into a Pass Through Trust Agreement, dated as of
October 6, 1998 (together, as amended, modified or supplemented from time to
time in accordance with the terms thereof, the "Pass Through Trust Agreement")
relating to America West Airlines Pass Through Trust 1998-1A-O (the "Pass
Through Trust") pursuant to which the America West Airlines Pass Through Trust,
Series 1998-1A-O Certificates referred to therein (the "Certificates") are being
issued;

            WHEREAS, America West and the Initial Purchasers have entered into a
Purchase Agreement dated as of September 24, 1998 (as amended, modified or
supplemented from time to time in accordance with the terms thereof, the
"Purchase Agreement") pursuant to which the Pass Through Trustee will issue and
sell the Certificates to the Initial Purchasers (the net proceeds of such sale
being herein referred to as the "Net Proceeds");

            WHEREAS, America West, the Pass Through Trustee, certain other pass
through trustees and certain other persons concurrently herewith are entering
into the Note Purchase Agreement, dated as of the date hereof (the "Note
Purchase
<PAGE>   5
                                                                               2


Agreement"), pursuant to which the Pass Through Trustee has agreed to acquire
from time to time on or prior to the Delivery Period Termination Date (as
defined in the Note Purchase Agreement) equipment notes (the "Equipment Notes")
issued to finance or refinance the acquisition of aircraft by America West, as
lessee or as owner, utilizing a portion of the Net Proceeds;

            WHEREAS, the Initial Purchasers and the Pass Through Trustee intend
that the Net Proceeds be held in escrow by the Escrow Agent on behalf of the
Investors, subject to withdrawal upon request by the Pass Through Trustee and
satisfaction of the conditions set forth in the Note Purchase Agreement for the
purpose of purchasing Equipment Notes, and that pending such withdrawal the Net
Proceeds be deposited on behalf of the Escrow Agent with ABN AMRO Bank N.V.,
acting through its Chicago branch, as Depositary (the "Depositary") under the
Deposit Agreement, dated as of the date hereof between the Depositary and the
Escrow Agent relating to the Pass Through Trust (as amended, modified or
supplemented from time to time in accordance with the terms thereof, the
"Deposit Agreement") pursuant to which, among other things, the Depositary will
pay interest for distribution to the Investors and establish accounts from which
the Escrow Agent shall make withdrawals upon request of and proper certification
by the Pass Through Trustee;

            WHEREAS, the Escrow Agent wishes to appoint the Paying Agent to pay
amounts required to be distributed to the Investors in accordance with this
Agreement; and

            WHEREAS, capitalized terms used but not defined herein shall have
the meanings ascribed to such terms in the Pass Through Trust Agreement.

            NOW, THEREFORE, in consideration of the obligations contained
herein, and for other good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the parties hereto hereby agree as
follows:

            SECTION 1.  Escrow Agent.

            Section 1.01. Appointment of Escrow Agent. Each of the Initial
Purchasers, for and on behalf of each of the Investors, hereby irrevocably
appoints, authorizes and directs the Escrow Agent to act as escrow agent and
fiduciary hereunder and under the Deposit Agreement for such specific purposes
and
<PAGE>   6
                                                                               3


with such powers as are specifically delegated to the Escrow Agent by the terms
of this Agreement, together with such other powers as are reasonably incidental
thereto. Any and all money received and held by the Escrow Agent under this
Agreement or the Deposit Agreement shall be held in escrow by the Escrow Agent
in accordance with the terms of this Agreement. This Agreement is irrevocable
and the Investors' rights with respect to any monies received and held in escrow
by the Escrow Agent under this Agreement or the Deposit Agreement shall only be
as provided under the terms and conditions of this Agreement and the Deposit
Agreement. The Escrow Agent (which term as used in this sentence shall include
reference to its affiliates and its own and its affiliates' officers, directors,
employees and agents): (a) shall have no duties or responsibilities except those
expressly set forth in this Agreement; (b) shall not be responsible to the Pass
Through Trustee or the Investors for any recitals, statements, representations
or warranties of any person other then itself contained in this Agreement or the
Deposit Agreement or for the failure by the Pass Through Trustee, the Investors
or any other person or entity (other than the Escrow Agent) to perform any of
its obligations hereunder (whether or not the Escrow Agent shall have any
knowledge thereof); and (c) shall not be responsible for any action taken or
omitted to be taken by it hereunder or provided for herein or in connection
herewith, except for its own willful misconduct or gross negligence (or simple
negligence in connection with the handling of funds) or breach of its
obligations hereunder.

            Section 1.02. Instruction; Etc. The Initial Purchasers, for and on
behalf of each of the Investors, hereby irrevocably instruct the Escrow Agent,
and the Escrow Agent agrees, (a) to enter into the Deposit Agreement, (b) to
appoint the Paying Agent as provided in this Agreement, (c) upon receipt at any
time and from time to time prior to the Termination Date (as defined below) of a
certificate substantially in the form of Exhibit B hereto (a "Withdrawal
Certificate") executed by the Pass Through Trustee, together with an attached
Notice of Purchase Withdrawal in substantially the form of Exhibit A to the
Deposit Agreement duly completed by the Pass Through Trustee (the "Applicable
Notice of Purchase Withdrawal" and the withdrawal to which it relates, a
"Purchase Withdrawal"), immediately to execute the Applicable Notice of Purchase
Withdrawal as Escrow Agent and transmit it to the Depositary by facsimile
transmission in accordance with the Deposit Agreement; provided that, upon the
request of the Pass Through Trustee after such transmission, the Escrow Agent
shall cancel such
<PAGE>   7
                                                                               4


Applicable Notice of Purchase Withdrawal, and (d) if there are any undrawn
Deposits (as defined in the Deposit Agreement) on the "Termination Date", which
shall mean the earlier of (i) February 1, 2000 and (ii) the day on which the
Escrow Agent receives notice from the Pass Through Trustee that the Pass Through
Trustee's obligation to purchase Equipment Notes under the Note Purchase
Agreement has terminated, to give notice to the Depositary (with a copy to the
Paying Agent) substantially in the form of Exhibit B to the Deposit Agreement
requesting a withdrawal of all of the remaining Deposits, together with accrued
and unpaid interest on such Deposits to the date of withdrawal, on the 35th day
after the date that such notice of withdrawal is given to the Depositary (or, if
not a Business Day, on the next succeeding Business Day) (a "Final Withdrawal"),
provided that if the day scheduled for the Final Withdrawal in accordance with
the foregoing is within 10 days before or after a Regular Distribution Date,
then the Escrow Agent shall request that such requested Final Withdrawal be made
on such Regular Distribution Date (the date of such requested withdrawal, the
"Final Withdrawal Date"). If for any reason the Escrow Agent shall have failed
to give the Final Withdrawal Notice to the Depositary on or before February 7,
2000, and there are unwithdrawn Deposits on such date, the Final Withdrawal Date
shall be deemed to be February 28, 2000.

            Section 1.03. Initial Escrow Amount; Issuance of Escrow Receipts.
The Escrow Agent hereby directs the Initial Purchasers to, and the Initial
Purchasers hereby acknowledge that on the date hereof they shall, irrevocably
deliver to the Depositary on behalf of the Escrow Agent, an amount in U.S.
dollars ("Dollars") and immediately available funds equal to $131,670,000 for
deposit on behalf of the Escrow Agent with the Depositary in accordance with
Section 2.1 of the Deposit Agreement. The Initial Purchasers hereby instruct the
Escrow Agent, upon receipt of such sum from the Initial Purchasers, to confirm
such receipt by executing and delivering to the Pass Through Trustee an Escrow
Receipt in the form of Exhibit A hereto (an "Escrow Receipt"), (a) to be affixed
by the Pass Through Trustee to each Certificate and (b) to evidence the same
percentage interest (the "Escrow Interest") in the Account Amounts (as defined
below) as the Fractional Undivided Interest in the Pass Through Trust evidenced
by the Certificate to which it is to be affixed. The Escrow Agent shall provide
to the Pass Through Trustee for attachment to each Certificate newly issued
under and in accordance with the Pass Through Trust Agreement an executed Escrow
Receipt as the Pass Through Trustee may from
<PAGE>   8
                                                                               5


time to time request of the Escrow Agent. Each Escrow Receipt shall be
registered by the Escrow Agent in a register (the "Register") maintained by the
Escrow Agent in the same name and same manner as the Certificate to which it is
attached and may not thereafter be detached from such Certificate to which it is
to be affixed prior to the distribution of the Final Withdrawal (the "Final
Distribution"). After the Final Distribution, no additional Escrow Receipts
shall be issued and the Pass Through Trustee shall request the return to the
Escrow Agent for cancellation of all outstanding Escrow Receipts.

            Section 1.04. Payments to Receiptholders. All payments and
distributions made to holders of an Escrow Receipt (collectively
"Receiptholders") in respect of the Escrow Receipt shall be made only from
amounts deposited in the Paying Agent Account (as defined below) ("Account
Amounts"). Each Receiptholder, by its acceptance of an Escrow Receipt, agrees
that (a) it will look solely to the Account Amounts for any payment or
distribution due to such Receiptholder pursuant to the terms of the Escrow
Receipt and this Agreement and (b) it will have no recourse to America West, the
Pass Through Trustee, the Paying Agent, the Escrow Agent or Wilmington Trust
Company, except as expressly provided herein or in the Pass Through Trust
Agreement. No Receiptholder shall have any right to vote or in any manner
otherwise control the operation and management of the Paying Agent Account or
the obligations of the parties hereto, nor shall anything set forth herein, or
contained in the terms of the Escrow Receipt, be construed so as to constitute
the Receiptholders from time to time as partners or members of an association.

            Section 1.05. Mutilated, Destroyed, Lost or Stolen Escrow Receipt.
If (a) any mutilated Escrow Receipt is surrendered to the Escrow Agent or the
Escrow Agent receives evidence to its satisfaction of the destruction, loss or
theft of any Escrow Receipt and (b) there is delivered to the Escrow Agent and
the Pass Through Trustee such security, indemnity or bond, as may be required by
them to hold each of them harmless, then, absent notice to the Escrow Agent or
the Pass Through Trustee that such destroyed, lost or stolen Escrow Receipt has
been acquired by a bona fide purchaser, and provided that the requirements of
Section 8-405 of the Uniform Commercial Code in effect in any applicable
jurisdiction are met, the Escrow Agent shall execute, authenticate and deliver,
in exchange for or in lieu of any such mutilated, destroyed, lost or stolen
Escrow Receipt, a new Escrow Receipt or Escrow Receipts and of like
<PAGE>   9
                                                                               6


Escrow Interest in the Account Amounts and bearing a number not
contemporaneously outstanding.

            In connection with the issuance of any new Escrow Receipt under this
Section 1.05, the Escrow Agent may require the payment of a sum sufficient to
cover any tax or other governmental charge that may be imposed in relation
thereto and any other expenses (including the fees and expenses of the Pass
Through Trustee and the Escrow Agent) connected therewith.

            Any duplicate Escrow Receipt issued pursuant to this Section 1.05
shall constitute conclusive evidence of the appropriate Escrow Interest in the
Account Amounts, as if originally issued, whether or not the lost, stolen or
destroyed Escrow Receipt shall be found at any time.

            The provisions of this Section are exclusive and shall preclude (to
the extent lawful) all other rights and remedies with respect to the replacement
or payment of mutilated, destroyed, lost or stolen Escrow Receipts.

            Section 1.06. Additional Escrow Amounts. On the date of any Purchase
Withdrawal, the Pass Through Trustee may re-deposit with the Depositary some or
all of the amounts so withdrawn in accordance with Section 2.4 of the Deposit
Agreement.

            Section 1.07. Resignation or Removal of Escrow Agent. Subject to the
appointment and acceptance of a successor Escrow Agent as provided below, the
Escrow Agent may resign at any time by giving 30 days' prior written notice
thereof to the Investors, but may not otherwise be removed except for cause by
the written consent of the Investors with respect to Investors representing
Escrow Interests aggregating not less than a majority in interest in the Account
Amounts (an "Action of Investors"). Upon any such resignation or removal, the
Investors, by an Action of Investors, shall have the right to appoint a
successor Escrow Agent. If no successor Escrow Agent shall have been so
appointed and shall have accepted such appointment within 30 days after the
retiring Escrow Agent's giving of notice of resignation or the removal of the
retiring Escrow Agent, then the retiring Escrow Agent may appoint a successor
Escrow Agent. Any successor Escrow Agent shall be a bank which has an office in
the United States with a combined capital and surplus of at least $100,000,000.
Upon the acceptance of any appointment as Escrow Agent hereunder by a
<PAGE>   10
                                                                               7


successor Escrow Agent, such successor Escrow Agent shall enter into such
documents as the Pass Through Trustee shall require and shall thereupon succeed
to and become vested with all the rights, powers, privileges and duties of the
retiring Escrow Agent, and the retiring Escrow Agent shall be discharged from
its duties and obligations hereunder. No resignation or removal of the Escrow
Agent shall be effective unless a written confirmation shall have been obtained
from each of Moody's Investors Service, Inc. and Standard & Poor's Rating
Services, a division of The McGraw-Hill Companies, Inc., that the replacement of
the Escrow Agent with the successor Escrow Agent will not result in (a) a
reduction of the rating for the Certificates below the then current rating for
the Certificates or (b) a withdrawal or suspension of the rating of the
Certificates.

            Section 1.08. Persons Deemed Owners. Prior to due presentment of a
Certificate for registration of transfer, the Escrow Agent and the Paying Agent
may treat the Person in whose name any Escrow Receipt is registered (as of the
day of determination) as the owner of such Escrow Receipt for the purpose of
receiving distributions pursuant to this Agreement and for all other purposes
whatsoever, and neither the Escrow Agent nor the Paying Agent shall be affected
by any notice to the contrary.

            Section 1.09. Further Assurances. The Escrow Agent agrees to take
such actions, and execute such other documents, as may be reasonably requested
by the Pass Through Trustee in order to effectuate the purposes of this
Agreement and the performance by the Escrow Agent of its obligations hereunder.

            SECTION 2. Paying Agent.

            Section 2.01. Appointment of Paying Agent. The Escrow Agent hereby
irrevocably appoints and authorizes the Paying Agent to act as its paying agent
hereunder, for the benefit of the Investors, for such specific purposes and
with such powers as are specifically delegated to the Paying Agent by the terms
of this Agreement, together with such other powers as are reasonably incidental
thereto. Any and all money received and held by the Paying Agent under this
Agreement or the Deposit Agreement shall be held in the Paying Agent Account for
the benefit of the Investors. The Paying Agent (which term as used in this
sentence shall include reference to its affiliates and its own and its
affiliates' officers, directors, employees and
<PAGE>   11
                                                                               8


agents): (a) shall have no duties or responsibilities except those expressly set
forth in this Agreement, and shall not by reason of this Agreement be a trustee
for the Escrow Agent; (b) shall not be responsible to the Escrow Agent for any
recitals, statements, representations or warranties of any person other then
itself contained in this Agreement or for the failure by the Escrow Agent or any
other person or entity (other than the Paying Agent) to perform any of its
obligations hereunder (whether or not the Paying Agent shall have any knowledge
thereof); and (c) except in respect of its express obligations hereunder, shall
not be responsible for any action taken or omitted to be taken by it hereunder
or provided for herein or in connection herewith, except for its own willful
misconduct or gross negligence (or simple negligence in connection with the
handling of funds).

            Section 2.02. Establishment of Paying Agent Account. The Paying
Agent shall establish a deposit account (the "Paying Agent Account") at
Wilmington Trust Company in the name of the Escrow Agent. It is expressly
understood by the parties hereto that the Paying Agent is acting as the paying
agent of the Escrow Agent hereunder and that no amounts on deposit in the Paying
Agent Account constitute part of the Trust Property.

            Section 2.03. Payments from Paying Agent Account. The Escrow Agent
hereby irrevocably instructs the Paying Agent, and the Paying Agent agrees to
act, as follows:

            (a) On each Interest Payment Date (as defined in the Deposit
      Agreement) or as soon thereafter as the Paying Agent has confirmed receipt
      in the Paying Agent Account from the Depositary of any amount in respect
      of accrued interest on the Deposits, the Paying Agent shall distribute out
      of the Paying Agent Account the entire amount deposited therein by the
      Depositary. There shall be so distributed to each Receiptholder of record
      on the 15th day (whether or not a Business Day) preceding such Interest
      Payment Date by check mailed to such Receiptholder, at the address
      appearing in the Register, such Receiptholder's pro rata share (based on
      the Escrow Interest in the Account Amounts held by such Receiptholder) of
      the total amount of interest deposited by the Depositary in the Paying
      Agent Account on such date, except that, with respect to Escrow Receipts
      registered on the Record Date in the name of DTC, such distribution shall
      be made by wire transfer in immediately available funds to the account
      designated by DTC.
<PAGE>   12
                                                                               9


            (b) Upon the confirmation by the Paying Agent of receipt in the
      Paying Agent Account from the Depositary of any amount in respect of the
      Final Withdrawal, the Paying Agent shall forthwith distribute the entire
      amount of the Final Withdrawal deposited therein by the Depositary. There
      shall be so distributed to each Receiptholder of record on the 15th day
      (whether or not a Business Day) preceding the Final Withdrawal Date by
      check mailed to such Receiptholder, at the address appearing in the
      Register, such Receiptholder's pro rata share (based on the Escrow
      Interest in the Account Amounts held by such Receiptholder) of the total
      amount in the Paying Agent Account on account of such Final Withdrawal,
      except that, with respect to Escrow Receipts registered on the Record Date
      in the name of DTC, such distribution shall be made by wire transfer in
      immediately available funds to the account designated by DTC.

            (c) If any payment of interest or principal in respect of the Final
      Withdrawal is not received by the Paying Agent within five days of the
      applicable date when due, then it shall be distributed to Receiptholders
      after actual receipt by the Paying Agent on the same basis as a Special
      Payment is distributed under the Pass Through Trust Agreement.

            (d) The Paying Agent shall include with any check mailed pursuant to
      this Section any notice required to be distributed under the Pass Through
      Trust Agreement that is furnished to the Paying Agent by the Pass Through
      Trustee.

            Section 2.04. Withholding Taxes. The Paying Agent shall exclude and
withhold from each distribution of accrued interest on the Deposits (as defined
in the Deposit Agreement) and any amount in respect of the Final Withdrawal any
and all withholding taxes applicable thereto as required by law. In addition,
the Paying Agent shall remit or cause to be remitted such amounts as would be
required by Section 1446 of the Internal Revenue Code of 1986, as amended, as if
the agreements of the Initial Purchasers set forth in this Agreement were
characterized as a partnership engaged in a U.S. trade or business for U.S.
federal income tax purposes and shall withhold or cause to be withheld such
amounts from amounts distributable to or for the benefit of Receiptholders or
beneficial owners of interests in Escrow Receipts that are not United States
persons
<PAGE>   13
                                                                              10


within the meaning of section 7701(a)(30) of the Internal Revenue Code of 1986,
as amended ("Non-U.S. Persons"). In this regard, the Paying Agent shall cause
the appropriate withholding agent to withhold with respect to such distributions
in the manner contemplated by Section 10.04 of Revenue Procedure 89-31 and
Treasury Regulation 1.1445-8(b)(3)) by filing a notice with the National
Association of Securities Dealers, Inc. substantially in the form of Exhibits C
and D on or before the date 10 days prior to the Record Date. The Paying Agent
shall mail such notice to the National Association of Securities Dealers no
later than the date 15 days prior to the Record Date. Investors that are not
United States Persons agree to furnish a taxpayer identification number ("TIN")
to the Paying Agent and the Paying Agent shall provide such TINs to the
appropriate U.S. withholding agent. The Paying Agent agrees to act as such
withholding agent (except to the extent contemplated above with respect to
withholding amounts as if the agreements of the Initial Purchasers as set forth
in this Agreement were characterized as a business engaged in a U.S. trade or
business for U.S. federal income tax purposes) and, in connection therewith,
whenever any present or future taxes or similar charges are required to be
withheld with respect to any amounts payable in respect of the Deposits (as
defined in the Deposit Agreement) or the escrow amounts, to withhold such
amounts and timely pay the same to the appropriate authority in the name of and
on behalf of the Receiptholders, that it will file any necessary withholding tax
returns or statements when due, and that, as promptly as possible after the
payment thereof, it will deliver to each such Receiptholder appropriate
documentation showing the payment thereof, together with such additional
documentary evidence as such Receiptholder may reasonably request from time to
time. The Paying Agent agrees to file any other information reports as it may be
required to file under United States law.

            Each Receiptholder or beneficial owner of an interest in an Escrow
Receipt that is a Non-U.S. Person, by its acceptance of an Escrow Receipt or a
beneficial interest therein, agrees to indemnify and hold harmless the Escrow
Agent and the Paying Agent from and against any improper failure to withhold
Taxes from amounts payable to it or for its benefit other than an improper
failure attributable to the gross negligence or willful misconduct of the Escrow
Agent or the Paying Agent, as the case may be.
<PAGE>   14
                                                                              11


            Section 2.05. Resignation or Removal of Paying Agent. Subject to the
appointment and acceptance of a successor Paying Agent as provided below, the
Paying Agent may resign at any time by giving 30 days' prior written notice
thereof to the Escrow Agent, but may not otherwise be removed except for cause
by the Escrow Agent. Upon any such resignation or removal, the Escrow Agent
shall have the right to appoint a successor Paying Agent. If no successor Paying
Agent shall have been so appointed and shall have accepted such appointment
within 30 days after the retiring Paying Agent's giving of notice of resignation
or the removal of the retiring Paying Agent, then the retiring Paying Agent may
appoint a successor Paying Agent. Any Successor Paying Agent shall be a bank
which has an office in the United States with a combined capital and surplus of
at least $100,000,000. Upon the acceptance of any appointment as Paying Agent
hereunder by a successor Paying Agent, such successor Paying Agent shall enter
into such documents as the Escrow Agent shall require and shall thereupon
succeed to and become vested with all the rights, powers, privileges and duties
of the retiring Paying Agent, and the retiring Paying Agent shall be discharged
from its duties and obligations hereunder.

            Section 2.06. Notice of Final Withdrawal. Promptly after receipt by
the Paying Agent of notice that the Escrow Agent has requested a Final
Withdrawal or that a Final Withdrawal will be made, the Paying Agent shall cause
notice of the distribution of the Final Withdrawal to be mailed to each of the
Receiptholders at its address as it appears in the Register. Such notice shall
be mailed not less than 15 days prior to the Final Withdrawal Date. Such notice
shall set forth:

            (i) the Final Withdrawal Date and the date for determining
      Receiptholders of record who shall be entitled to receive distributions in
      respect of the Final Withdrawal,

            (ii) the amount of the payment in respect of the Final Withdrawal
      for each $1,000 face amount Certificate (based on information provided by
      the Pass Through Trustee) and the amount thereof constituting unused
      Deposits (as defined in the Deposit Agreement) and interest thereon, and

            (iii) if the Final Withdrawal Date is the same date as a Regular
      Distribution Date, the total amount to be received on such date for each
      $1,000
<PAGE>   15
                                                                              12


      face amount Certificate (based on information provided by the Pass Through
      Trustee).

            Such mailing may include any notice required to be given to
Certificateholders in connection with such distribution pursuant to the Pass
Through Trust Agreement.

            SECTION 3. Payments. If, notwithstanding the instructions in Section
4 of the Deposit Agreement that all amounts payable to the Escrow Agent under
the Deposit Agreement be paid by the Depositary directly to the Paying Agent or
the Pass Through Trustee (depending on the circumstances), the Escrow Agent
receives any payment thereunder, then the Escrow Agent shall forthwith pay such
amount in Dollars and in immediately available funds by wire transfer to (a) in
the case of a payment of accrued interest on the Deposits (as defined in the
Deposit Agreement) or any Final Withdrawal, directly to the Paying Agent Account
and (b) in the case of any Purchase Withdrawal, directly to the Pass Through
Trustee or its designee as specified and in the manner provided in the
Applicable Notice of Purchase Withdrawal. The Escrow Agent hereby waives any and
all rights of set-off, combination of accounts, right of retention or similar
right (whether arising under applicable law, contract or otherwise) it may have
against amounts payable to the Paying Agent howsoever arising.

            SECTION 4. Other Actions. The Escrow Agent shall take such other
actions under or in respect of the Deposit Agreement (including, without
limitation, the enforcement of the obligations of the Depositary thereunder) as
the Investors, by an Action of Investors, may from time to time request.

            SECTION 5.  Representations and Warranties of the Escrow Agent.
The Escrow Agent represents and warrants to America West, the Investors, the
Paying Agent and the Pass Through Trustee as follows:

            (i) it is a banking corporation duly organized and validly existing
      in good standing under the laws of the State of Delaware;

            (ii) it has full power, authority and legal right to conduct its
      business and operations as currently conducted and to enter into and
      perform its obligations under this Agreement and the Deposit Agreement;
<PAGE>   16
                                                                              13


            (iii) the execution, delivery and performance of each of this
      Agreement and the Deposit Agreement have been duly authorized by all
      necessary corporate action on the part of it and do not require any
      stockholder approval, or approval or consent of any trustee or holder of
      any indebtedness or obligations of it, and each such document has been
      duly executed and delivered by it and constitutes its legal, valid and
      binding obligations enforceable against it in accordance with the terms
      hereof or thereof except as such enforceability may be limited by
      bankruptcy, insolvency, moratorium, reorganization or other similar laws
      or equitable principles of general application to or affecting the
      enforcement of creditors' rights generally (regardless of whether such
      enforceability is considered in a proceeding in equity or at law);

            (iv) no authorization, consent or approval of or other action by,
      and no notice to or filing with, any United States federal or state
      governmental authority or regulatory body is required for the execution,
      delivery or performance by it of this Agreement or the Deposit Agreement;

            (v) neither the execution, delivery or performance by it of this
      Agreement or the Deposit Agreement, nor compliance with the terms and
      provisions hereof or thereof, conflicts or will conflict with or results
      or will result in a breach or violation of any of the terms, conditions or
      provisions of, or will require any consent or approval under, any law,
      governmental rule or regulation or the charter documents, as amended, or
      bylaws, as amended, of it or any similar instrument binding on it or any
      order, writ, injunction or decree of any court or governmental authority
      against it or by which it or any of its properties is bound or any
      indenture, mortgage or contract or other agreement or instrument to which
      it is a party or by which it or any of its properties is bound, or
      constitutes or will constitute a default thereunder or results or will
      result in the imposition of any lien upon any of its properties; and
<PAGE>   17
                                                                              14


            (vi) there are no pending or, to its knowledge, threatened actions,
      suits, investigations or proceedings (whether or not purportedly on behalf
      of it) against or affecting it or any of its property before or by any
      court or administrative agency which, if adversely determined, (A) would
      adversely affect the ability of it to perform its obligations under this
      Agreement or the Deposit Agreement or (B) would call into question or
      challenge the validity of this Agreement or the Deposit Agreement or the
      enforceability hereof or thereof in accordance with the terms hereof or
      thereof, nor is the Escrow Agent in default with respect to any order of
      any court, governmental authority, arbitration board or administrative
      agency so as to adversely affect its ability to perform its obligations
      under this Agreement or the Deposit Agreement.

            SECTION 6. Representations and Warranties of the Paying Agent. The
Paying Agent represents and warrants to America West, the Investors, the Escrow
Agent and the Pass Through Trustee as follows:

            (i) it is a banking corporation duly organized and validly existing
      in good standing under the laws of the State of Delaware;

            (ii) it has full power, authority and legal right to conduct its
      business and operations as currently conducted and to enter into and
      perform its obligations under this Agreement;

            (iii) the execution, delivery and performance of this Agreement has
      been duly authorized by all necessary corporate action on the part of it
      and does not require any stockholder approval, or approval or consent of
      any trustee or holder of any indebtedness or obligations of it, and such
      document has been duly executed and delivered by it and constitutes its
      legal, valid and binding obligations enforceable against it in accordance
      with the terms hereof except as such enforceability may be limited by
      bankruptcy, insolvency, moratorium, reorganization or other similar laws
      or equitable principles of general application to or affecting the
      enforcement of creditors' rights generally (regardless of whether
<PAGE>   18
                                                                              15


      such enforceability is considered in a proceeding in equity or at law);

            (iv) no authorization, consent or approval of or other action by,
      and no notice to or filing with, any United States federal or state
      governmental authority or regulatory body is required for the execution,
      delivery or performance by it of this Agreement;

            (v) neither the execution, delivery or performance by it of this
      Agreement, nor compliance with the terms and provisions hereof, conflicts
      or will conflict with or results or will result in a breach or violation
      of any of the terms, conditions or provisions of, or will require any
      consent or approval under, any law, governmental rule or regulation or the
      charter documents, as amended, or bylaws, as amended, of it or any similar
      instrument binding on it or any order, writ, injunction or decree of any
      court or governmental authority against it or by which it or any of its
      properties is bound or any indenture, mortgage or contract or other
      agreement or instrument to which it is a party or by which it or any of
      its properties is bound, or constitutes or will constitute a default
      thereunder or results or will result in the imposition of any lien upon
      any of its properties; and

            (vi) there are no pending or, to its knowledge, threatened actions,
      suits, investigations or proceedings (whether or not purportedly on behalf
      of it) against or affecting it or any of its property before or by any
      court or administrative agency which, if adversely determined, (A) would
      adversely affect the ability of it to perform its obligations under this
      Agreement or (B) would call into question or challenge the validity of
      this Agreement or the enforceability hereof in accordance with the terms
      hereof, nor is the Paying Agent in default with respect to any order of
      any court, governmental authority, arbitration board or administrative
      agency so as to adversely affect its ability to perform its obligations
      under this Agreement.

            SECTION 7. Indemnification. Except for actions expressly required of
the Escrow Agent or the Paying Agent hereunder, each of the Escrow Agent and the
Paying Agent shall
<PAGE>   19
                                                                              16


in all cases be fully justified in failing or refusing to act hereunder unless
it shall have been indemnified (both in such capacities and individually) by the
party requesting such action in a manner reasonably satisfactory to it against
any and all liability and expense which may be incurred by it by reason of
taking or continuing to take any such action. In the event America West requests
any amendment to any Operative Agreement (as defined in the Note Purchase
Agreement), the Pass Through Trustee agrees to pay all reasonable fees and
expenses (including, without limitation, fees and disbursements of counsel) of
the Escrow Agent and the Paying Agent in connection therewith.

            SECTION 8. Amendment, Etc. Upon request of the Pass Through Trustee
and approval by an Action of Investors, the Escrow Agent shall enter into an
amendment to this Agreement, so long as such amendment does not adversely affect
the rights or obligations of the Escrow Agent or the Paying Agent, provided that
upon request of the Pass Through Trustee and without any consent of the
Investors, the Escrow Agent shall enter into an amendment to this Agreement for
any of the following purposes:

            (1) to correct or supplement any provision in this Agreement which
      may be defective or inconsistent with any other provision herein or to
      cure any ambiguity or correct any mistake or to modify any other provision
      with respect to matters or questions arising under this Agreement,
      provided that any such action shall not materially adversely affect the
      interests of the Investors; or

            (2) to comply with any requirement of the SEC, applicable law, rules
      or regulations of any exchange or quotation system on which the
      Certificates are listed or any regulatory body or the Registration Rights
      Agreement to effectuate the Exchange Offer; or

            (3) to evidence and provide for the acceptance of appointment under
      this Agreement of a successor Escrow Agent, successor Paying Agent or
      successor Pass Through Trustee.

            SECTION 9. Notices. Unless otherwise expressly provided herein, any
notice or other communication under this Agreement shall be in writing
(including by facsimile) and shall be deemed to be given and effective upon
receipt thereof (or, if received outside of business hours, on the next open of
business
<PAGE>   20
                                                                              17


on a Business Day). All notices shall be sent to (a) in the case of the
Investors, as their respective addresses shall appear in the Register, (b) in
the case of the Escrow Agent, Wilmington Trust Company, 1100 North Market
Street, Wilmington, Delaware 19890, Attention: Corporate Trust Administration
(Telecopier: 302-651-8882), (c) in the case of the Pass Through Trustee,
Wilmington Trust Company, 1100 North Market Street, Wilmington, Delaware 19890,
Attention: Corporate Trust Administration (Telecopier: 302-651-8882), or (d) in
the case of the Paying Agent, Wilmington Trust Company, 1100 North Market
Street, Wilmington, Delaware 19890, Attention: Corporate Trust Administration
(Telecopier: 302-651-8882), in each case with a copy to America West, America
West Airlines, Inc., 4000 East Sky Harbor Boulevard, Phoenix, Arizona 95043,
Attention: Vice President - Treasurer (Telecopier: (602) 693-5886) (or at such
other address as any such party may specify from time to time in a written
notice to the other parties). On or prior to the execution of this Agreement,
the Pass Through Trustee has delivered to the Escrow Agent a certificate
containing specimen signatures of the representatives of the Pass Through
Trustee who are authorized to give notices and instructions with respect to this
Agreement. The Escrow Agent may conclusively rely on such certificate until the
Escrow Agent receives written notice from the Pass Through Trustee to the
contrary.

            SECTION 10. Transfer. No party hereto shall be entitled to assign or
otherwise transfer this Agreement (or any interest herein) other than (in the
case of the Escrow Agent) to a successor escrow agent under Section 1.06 hereof
or (in the case of the Paying Agent) to a successor paying agent under Section
2.04 hereof, and any purported assignment in violation thereof shall be void.
This Agreement shall be binding upon the parties hereto and their respective
successors and (in the case of the Escrow Agent and the Paying Agent) their
respective permitted assigns. Upon the occurrence of the Transfer (as defined
below) contemplated by the Assignment and Assumption Agreement (as defined
below), the Pass Through Trustee shall (without further act) be deemed to have
transferred all of its right, title and interest in and to this Agreement to the
trustee of the Successor Trust (as defined below) and, thereafter, the trustee
of the Successor Trust shall be deemed to be the "Pass Through Trustee"
hereunder with the rights and obligations of the "Pass Through Trustee"
hereunder and each reference herein to "America West Airlines Pass Through Trust
"1998-1A-O" shall be deemed to be a reference to "America West Airlines Pass
Through Trust 1998-1A-S". The parties hereto
<PAGE>   21
                                       18


hereby acknowledge and consent to the Transfer contemplated by the Assignment
and Assumption Agreement. As used herein, "Transfer" means the transfers of the
assets to the Successor Trust contemplated by the Assignment and Assumption
Agreement; "Assignment and Assumption Agreement" means the Assignment and
Assumption Agreement to be entered into between the Pass Through Trustee and the
trustee of the Successor Trust, substantially in the form of Exhibit D to the
Pass Through Trust Agreement; "Successor Trust" means the America West Airlines
Pass Through Trust 1998-1A-S.

            SECTION 11. Entire Agreement. This Agreement sets forth all of the
promises, covenants, agreements, conditions and understandings among the Escrow
Agent, the Paying Agent, the Initial Purchasers and the Pass Through Trustee
with respect to the subject matter hereof, and supersedes all prior and
contemporaneous agreements and undertakings, inducements or conditions, express
or implied, oral or written.

            SECTION 12. Governing Law.  This Agreement shall be governed by,
and construed in accordance with, the law of the State of New York.

            SECTION 13. Waiver of Jury Trial Right. EACH OF THE ESCROW AGENT,
THE PAYING AGENT, THE INVESTORS AND THE PASS THROUGH TRUSTEE ACKNOWLEDGES AND
ACCEPTS THAT IN ANY SUIT, ACTION OR PROCEEDING ARISING OUT OF OR RELATING TO
THIS AGREEMENT SUCH PARTY IRREVOCABLY WAIVES ITS RIGHT TO A TRIAL BY JURY.

            SECTION 14. Counterparts.  This Agreement may be executed in one
or more counterparts, all of which taken together shall constitute one
instrument.
<PAGE>   22
                                       19


            IN WITNESS WHEREOF, the Escrow Agent, the Paying Agent, the Initial
Purchasers and the Pass Through Trustee have caused this Escrow and Paying Agent
Agreement (Class A) to be duly executed as of the day and year first above
written.

                                    WILMINGTON TRUST COMPANY, as Escrow Agent

                                   
                                    By /s/ Norma P. Closs
                                       --------------------------------
                                     Name: Norma P. Closs
                                       Title: Vice President


                                    MORGAN STANLEY & CO. INCORPORATED,
                                    DONALDSON, LUFKIN & JENRETTE SECURITIES
                                    CORPORATION,
                                    MERRILL LYNCH, PIERCE, FENNER & SMITH
                                    INCORPORATED and
                                    SALOMON SMITH BARNEY INC.,
                                       as Initial Purchasers


                                    By: MORGAN STANLEY & CO.
                                         INCORPORATED


                                    By /s/ Tom Cahill
                                       --------------------------------
                                       Name: Tom Cahill
                                       Title:

                                    WILMINGTON TRUST COMPANY, not in its
                                    individual capacity, but solely as Pass
                                    Through Trustee for and on behalf of America
                                    West Airlines Pass Through Trust
                                    1998-1A-O


                                    By /s/ James P. Lawler
                                       ----------------------------------
                                       Name: James P. Lawler
                                       Title: Vice President
<PAGE>   23
                                                                              20


                                    WILMINGTON TRUST COMPANY,
                                    as Paying Agent


                                    By /s/ Norma P. Closs
                                       ------------------------
                                       Name: Norma P. Closs
                                       Title: Vice President
<PAGE>   24
                                                                              


                                                                       EXHIBIT A

                  AMERICA WEST AIRLINES 1998-1A ESCROW RECEIPT

                                     No. __

            This Escrow Receipt evidences a fractional undivided interest in
amounts ("Account Amounts") from time to time deposited into a certain paying
agent account (the "Paying Agent Account") described in the Escrow and Paying
Agent Agreement (Class A) dated as of October 6, 1998 (as amended, modified or
supplemented from time to time, the "Escrow and Paying Agent Agreement") among
Wilmington Trust Company, as Escrow Agent (in such capacity, together with its
successors in such capacity, the "Escrow Agent"), Morgan Stanley & Co.
Incorporated, Donaldson, Lufkin & Jenrette Securities Corporation , Merrill
Lynch, Pierce, Fenner & Smith Incorporated and Salomon Smith Barney Inc., as
Initial Purchasers, Wilmington Trust Company, as Pass Through Trustee (in such
capacity, together with its successors in such capacity, the "Pass Through
Trustee") and Wilmington Trust Company, as paying agent (in such capacity,
together with its successors in such capacity, the "Paying Agent"). Capitalized
terms not defined herein shall have the meanings assigned to them in the Escrow
and Paying Agent Agreement.

            This Escrow Receipt is issued under and is subject to the terms,
provisions and conditions of the Escrow and Paying Agent Agreement. By virtue of
its acceptance hereof the holder of this Escrow Receipt assents and agrees to be
bound by the provisions of the Escrow and Paying Agent Agreement and this Escrow
Receipt.

            This Escrow Receipt represents a fractional undivided interest in
amounts deposited from time to time in the Paying Agent Account, and grants or
represents no rights, benefits or interests of any kind in respect of any assets
or property other than such amounts. This Escrow Receipt evidences the same
percentage interest in the Account Amounts as the Fractional Undivided Interest
in the Pass Through Trust evidenced by the Certificate to which this Escrow
Receipt is affixed.

            All payments and distributions made to Receiptholders in respect of
the Escrow Receipt shall be made only from Account Amounts deposited in the
Paying Agent Account. The holder of this Escrow Receipt, by its acceptance of
this Escrow Receipt, agrees that it will look solely to the Account Amounts for
any payment or distribution due to it pursuant to this Escrow
<PAGE>   25
                                                                               2


Receipt and that it will not have any recourse to America West, the Pass Through
Trustee, the Paying Agent or the Escrow Agent, except as expressly provided
herein or in the Pass Through Trust Agreement. No Receiptholder of this Escrow
Receipt shall have any right to vote or in any manner otherwise control the
operation and management of the Paying Agent Account, nor shall anything set
forth herein, or contained in the terms of this Escrow Receipt, be construed so
as to constitute the Receiptholders from time to time as partners or members of
an association.

            This Escrow Receipt may not be assigned or transferred except in
connection with the assignment or transfer of the Certificate to which this
Escrow Receipt is affixed. After payment to the holder hereof of its Escrow
Interest in the Final Distribution, upon the request of the Pass Through
Trustee, the holder hereof will return this Escrow Receipt to the Pass Through
Trustee.

            The Paying Agent may treat the person in whose name the Certificate
to which this Escrow Receipt is attached as the owner hereof for all purposes,
and the Paying Agent shall not be affected by any notice to the contrary.

            THIS ESCROW RECEIPT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE
WITH THE LAW OF THE STATE OF NEW YORK.

            IN WITNESS WHEREOF, the Escrow Agent has caused this Escrow Receipt
to be duly executed.

Dated: ______________, 199_

                                    WILMINGTON TRUST COMPANY,
                                    as Escrow Agent

                                    By __________________________
                                       Name:
                                       Title:
<PAGE>   26
                                                                       EXHIBIT B

                             WITHDRAWAL CERTIFICATE
                                    (Class A)

                            WILMINGTON TRUST COMPANY,
                                 as Escrow Agent

Dear Sirs:

            Reference is made to the Escrow and Paying Agent Agreement, dated as
of October 6, 1998 (the "Agreement"). We hereby certify to you that the
conditions to the obligations of the undersigned to execute a Participation
Agreement pursuant to the Note Purchase Agreement have been satisfied. Pursuant
to Section 1.02(c) of the Agreement, please execute the attached Notice of
Withdrawal and immediately transmit by facsimile to the Depositary, at (312)
606-8428, Attention: Vice President - Aerospace.


                                    Very truly yours,

                                    WILMINGTON TRUST COMPANY,
                                    not in its individual capacity but
                                    solely as Pass Through Trustee


                                    By __________________________
                                       Name:
                                       Title:



Dated:  ____________, 199_



<PAGE>   1
                                                                    Exhibit 4.19



                                                                       EXECUTION





                        ESCROW AND PAYING AGENT AGREEMENT
                                    (Class B)

                           Dated as of October 6, 1998

                                      among

                            WILMINGTON TRUST COMPANY
                                 as Escrow Agent

                       MORGAN STANLEY & CO. INCORPORATED,
               DONALDSON, LUFKIN & JENRETTE SECURITIES CORPORATION
               MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED
                                       and
                            SALOMON SMITH BARNEY INC.

                              as Initial Purchasers

                            WILMINGTON TRUST COMPANY,
                         not in its individual capacity,
                       but solely as Pass Through Trustee
                              for and on behalf of
               America West Airlines Pass Through Trust 1998-1B-O

                             as Pass Through Trustee

                                       and

                            WILMINGTON TRUST COMPANY

                                 as Paying Agent
<PAGE>   2
                               TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                             Page
                                                                                                             ----
<S>                        <C>                                                                               <C>
SECTION 1.                 Escrow Agent.......................................................................2


Section 1.01.              Appointment of Escrow Agent........................................................2


Section 1.02.              Instruction; Etc...................................................................3


Section 1.03.              Initial Escrow Amount; Issuance of Escrow
                           Receipts...........................................................................4


Section 1.04.              Payments to Receiptholders.........................................................5


Section 1.05.              Mutilated, Destroyed, Lost or Stolen Escrow Receipt................................5


Section 1.06.              Additional Escrow Amounts..........................................................6


Section 1.07.              Resignation or Removal of Escrow Agent.............................................6


Section 1.08.              Persons Deemed Owners..............................................................7


Section 1.09.              Further Assurances.................................................................7


SECTION 2.                 Paying Agent.......................................................................7


Section 2.01.              Appointment of Paying Agent........................................................7


Section 2.02.              Establishment of Paying Agent Account..............................................8


Section 2.03.              Payments from Paying Agent Account.................................................8


Section 2.04.              Withholding Taxes..................................................................9


Section 2.05.              Resignation or Removal of Paying Agent............................................11
</TABLE>

                                       i
<PAGE>   3
<TABLE>
<CAPTION>
                                                                                                             Page
                                                                                                             ----
<S>                        <C>                                                                               <C>
Section 2.06.              Notice of Final Withdrawal........................................................11


SECTION 3.                 Payments..........................................................................12


SECTION 4.                 Other Actions.....................................................................12


SECTION 5.                 Representations and Warranties of the
                           Escrow Agent......................................................................12


SECTION 6.                 Representations and Warranties of the
                           Paying Agent......................................................................14


SECTION 7.                 Indemnification...................................................................15


SECTION 8.                 Amendment, Etc....................................................................16


SECTION 9.                 Notices. .........................................................................16


SECTION 10.                Transfer..........................................................................17


SECTION 11.                Entire Agreement..................................................................18


SECTION 12.                Governing Law.....................................................................18


SECTION 13.                Waiver of Jury Trial Right........................................................18


SECTION 14.                Counterparts......................................................................18
</TABLE>




Exhibit A                  Escrow Receipt

Exhibit B                  Withdrawal Certificate

                                       ii
<PAGE>   4
                  ESCROW AND PAYING AGENT AGREEMENT (Class B) dated as of
October 6, 1998 (as amended, modified or supplemented from time to time, this
"Agreement") among WILMINGTON TRUST COMPANY, a Delaware banking corporation, as
Escrow Agent (in such capacity, together with its successors in such capacity,
the "Escrow Agent"); MORGAN STANLEY & CO. INCORPORATED, DONALDSON, LUFKIN &
JENRETTE SECURITIES CORPORATION, MERRILL LYNCH, PIERCE, FENNER & SMITH
INCORPORATED and SALOMON SMITH BARNEY INC., as Initial Purchasers of the
Certificates referred to below (the "Initial Purchasers" and together with their
respective transferees and assigns as registered owners of the Certificates, the
"Investors") under the Purchase Agreement referred to below; Wilmington Trust
Company, a Delaware banking corporation, not in its individual capacity except
as otherwise expressly provided herein, but solely as trustee (in such capacity,
together with its successors in such capacity, the "Pass Through Trustee") under
the Pass Through Trust Agreement referred to below; and WILMINGTON TRUST
COMPANY, a Delaware banking corporation, as paying agent hereunder (in such
capacity, together with its successors in such capacity, the "Paying Agent").

                               W I T N E S S E T H

                  WHEREAS, America West Airlines, Inc. ("America West") and the
Pass Through Trustee have entered into a Pass Through Trust Agreement, dated as
of October 6, 1998 (together, as amended, modified or supplemented from time to
time in accordance with the terms thereof, the "Pass Through Trust Agreement")
relating to America West Airlines Pass Through Trust 1998-1B-O (the "Pass
Through Trust") pursuant to which the America West Airlines Pass Through Trust,
Series 1998-1B-O Certificates referred to therein (the "Certificates") are being
issued;

                  WHEREAS, America West and the Initial Purchasers have entered
into a Purchase Agreement dated as of September 24, 1998 (as amended, modified
or supplemented from time to time in accordance with the terms thereof, the
"Purchase Agreement") pursuant to which the Pass Through Trustee will issue and
sell the Certificates to the Initial Purchasers (the net proceeds of such sale
being herein referred to as the "Net Proceeds");

                  WHEREAS, America West, the Pass Through Trustee, certain other
pass through trustees and certain other persons concurrently herewith are
entering into the Note Purchase Agreement, dated as of the date hereof (the
"Note Purchase 
<PAGE>   5
                                                                               2
Agreement"), pursuant to which the Pass Through Trustee has agreed to acquire
from time to time on or prior to the Delivery Period Termination Date (as
defined in the Note Purchase Agreement) equipment notes (the "Equipment Notes")
issued to finance or refinance the acquisition of aircraft by America West, as
lessee or as owner, utilizing a portion of the Net Proceeds;

                  WHEREAS, the Initial Purchasers and the Pass Through Trustee
intend that the Net Proceeds be held in escrow by the Escrow Agent on behalf of
the Investors, subject to withdrawal upon request by the Pass Through Trustee
and satisfaction of the conditions set forth in the Note Purchase Agreement for
the purpose of purchasing Equipment Notes, and that pending such withdrawal the
Net Proceeds be deposited on behalf of the Escrow Agent with ABN AMRO Bank N.V.,
acting through its Chicago branch, as Depositary (the "Depositary") under the
Deposit Agreement, dated as of the date hereof between the Depositary and the
Escrow Agent relating to the Pass Through Trust (as amended, modified or
supplemented from time to time in accordance with the terms thereof, the
"Deposit Agreement") pursuant to which, among other things, the Depositary will
pay interest for distribution to the Investors and establish accounts from which
the Escrow Agent shall make withdrawals upon request of and proper certification
by the Pass Through Trustee;

                  WHEREAS, the Escrow Agent wishes to appoint the Paying Agent
to pay amounts required to be distributed to the Investors in accordance with
this Agreement; and

                  WHEREAS, capitalized terms used but not defined herein shall
have the meanings ascribed to such terms in the Pass Through Trust Agreement.

                  NOW, THEREFORE, in consideration of the obligations contained
herein, and for other good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the parties hereto hereby agree as
follows:

                  SECTION 1. Escrow Agent.

                  Section 1.01. Appointment of Escrow Agent. Each of the Initial
Purchasers, for and on behalf of each of the Investors, hereby irrevocably
appoints, authorizes and directs the Escrow Agent to act as escrow agent and
fiduciary hereunder and under the Deposit Agreement for such specific purposes
and
<PAGE>   6
                                                                               3

with such powers as are specifically delegated to the Escrow Agent by the terms
of this Agreement, together with such other powers as are reasonably incidental
thereto. Any and all money received and held by the Escrow Agent under this
Agreement or the Deposit Agreement shall be held in escrow by the Escrow Agent
in accordance with the terms of this Agreement. This Agreement is irrevocable
and the Investors' rights with respect to any monies received and held in escrow
by the Escrow Agent under this Agreement or the Deposit Agreement shall only be
as provided under the terms and conditions of this Agreement and the Deposit
Agreement. The Escrow Agent (which term as used in this sentence shall include
reference to its affiliates and its own and its affiliates' officers, directors,
employees and agents): (a) shall have no duties or responsibilities except those
expressly set forth in this Agreement; (b) shall not be responsible to the Pass
Through Trustee or the Investors for any recitals, statements, representations
or warranties of any person other then itself contained in this Agreement or the
Deposit Agreement or for the failure by the Pass Through Trustee, the Investors
or any other person or entity (other than the Escrow Agent) to perform any of
its obligations hereunder (whether or not the Escrow Agent shall have any
knowledge thereof); and (c) shall not be responsible for any action taken or
omitted to be taken by it hereunder or provided for herein or in connection
herewith, except for its own willful misconduct or gross negligence (or simple
negligence in connection with the handling of funds) or breach of its
obligations hereunder.

                  Section 1.02. Instruction; Etc. The Initial Purchasers, for
and on behalf of each of the Investors, hereby irrevocably instruct the Escrow
Agent, and the Escrow Agent agrees, (a) to enter into the Deposit Agreement, (b)
to appoint the Paying Agent as provided in this Agreement, (c) upon receipt at
any time and from time to time prior to the Termination Date (as defined below)
of a certificate substantially in the form of Exhibit B hereto (a "Withdrawal
Certificate") executed by the Pass Through Trustee, together with an attached
Notice of Purchase Withdrawal in substantially the form of Exhibit A to the
Deposit Agreement duly completed by the Pass Through Trustee (the "Applicable
Notice of Purchase Withdrawal" and the withdrawal to which it relates, a
"Purchase Withdrawal"), immediately to execute the Applicable Notice of Purchase
Withdrawal as Escrow Agent and transmit it to the Depositary by facsimile
transmission in accordance with the Deposit Agreement; provided that, upon the
request of the Pass Through Trustee after such transmission, the Escrow Agent
shall cancel such
<PAGE>   7
                                                                               4

Applicable Notice of Purchase Withdrawal, and (d) if there are any undrawn
Deposits (as defined in the Deposit Agreement) on the "Termination Date", which
shall mean the earlier of (i) February 1, 2000 and (ii) the day on which the
Escrow Agent receives notice from the Pass Through Trustee that the Pass Through
Trustee's obligation to purchase Equipment Notes under the Note Purchase
Agreement has terminated, to give notice to the Depositary (with a copy to the
Paying Agent) substantially in the form of Exhibit B to the Deposit Agreement
requesting a withdrawal of all of the remaining Deposits, together with accrued
and unpaid interest on such Deposits to the date of withdrawal, on the 35th day
after the date that such notice of withdrawal is given to the Depositary (or, if
not a Business Day, on the next succeeding Business Day) (a "Final Withdrawal"),
provided that if the day scheduled for the Final Withdrawal in accordance with
the foregoing is within 10 days before or after a Regular Distribution Date,
then the Escrow Agent shall request that such requested Final Withdrawal be made
on such Regular Distribution Date (the date of such requested withdrawal, the
"Final Withdrawal Date"). If for any reason the Escrow Agent shall have failed
to give the Final Withdrawal Notice to the Depositary on or before February 7,
2000, and there are unwithdrawn Deposits on such date, the Final Withdrawal Date
shall be deemed to be February 28, 2000.

                  Section 1.03. Initial Escrow Amount; Issuance of Escrow
Receipts. The Escrow Agent hereby directs the Initial Purchasers to, and the
Initial Purchasers hereby acknowledge that on the date hereof they shall,
irrevocably deliver to the Depositary on behalf of the Escrow Agent, an amount
in U.S. dollars ("Dollars") and immediately available funds equal to $41,154,000
for deposit on behalf of the Escrow Agent with the Depositary in accordance with
Section 2.1 of the Deposit Agreement. The Initial Purchasers hereby instruct the
Escrow Agent, upon receipt of such sum from the Initial Purchasers, to confirm
such receipt by executing and delivering to the Pass Through Trustee an Escrow
Receipt in the form of Exhibit A hereto (an "Escrow Receipt"), (a) to be affixed
by the Pass Through Trustee to each Certificate and (b) to evidence the same
percentage interest (the "Escrow Interest") in the Account Amounts (as defined
below) as the Fractional Undivided Interest in the Pass Through Trust evidenced
by the Certificate to which it is to be affixed. The Escrow Agent shall provide
to the Pass Through Trustee for attachment to each Certificate newly issued
under and in accordance with the Pass Through Trust Agreement an executed Escrow
Receipt as the Pass Through Trustee may from 
<PAGE>   8
                                                                               5

time to time request of the Escrow Agent. Each Escrow Receipt shall be
registered by the Escrow Agent in a register (the "Register") maintained by the
Escrow Agent in the same name and same manner as the Certificate to which it is
attached and may not thereafter be detached from such Certificate to which it is
to be affixed prior to the distribution of the Final Withdrawal (the "Final
Distribution"). After the Final Distribution, no additional Escrow Receipts
shall be issued and the Pass Through Trustee shall request the return to the
Escrow Agent for cancellation of all outstanding Escrow Receipts.

                  Section 1.04. Payments to Receiptholders. All payments and
distributions made to holders of an Escrow Receipt (collectively
"Receiptholders") in respect of the Escrow Receipt shall be made only from
amounts deposited in the Paying Agent Account (as defined below) ("Account
Amounts"). Each Receiptholder, by its acceptance of an Escrow Receipt, agrees
that (a) it will look solely to the Account Amounts for any payment or
distribution due to such Receiptholder pursuant to the terms of the Escrow
Receipt and this Agreement and (b) it will have no recourse to America West, the
Pass Through Trustee, the Paying Agent, the Escrow Agent or Wilmington Trust
Company, except as expressly provided herein or in the Pass Through Trust
Agreement. No Receiptholder shall have any right to vote or in any manner
otherwise control the operation and management of the Paying Agent Account or
the obligations of the parties hereto, nor shall anything set forth herein, or
contained in the terms of the Escrow Receipt, be construed so as to constitute
the Receiptholders from time to time as partners or members of an association.

                  Section 1.05. Mutilated, Destroyed, Lost or Stolen Escrow
Receipt. If (a) any mutilated Escrow Receipt is surrendered to the Escrow Agent
or the Escrow Agent receives evidence to its satisfaction of the destruction,
loss or theft of any Escrow Receipt and (b) there is delivered to the Escrow
Agent and the Pass Through Trustee such security, indemnity or bond, as may be
required by them to hold each of them harmless, then, absent notice to the
Escrow Agent or the Pass Through Trustee that such destroyed, lost or stolen
Escrow Receipt has been acquired by a bona fide purchaser, and provided that the
requirements of Section 8-405 of the Uniform Commercial Code in effect in any
applicable jurisdiction are met, the Escrow Agent shall execute, authenticate
and deliver, in exchange for or in lieu of any such mutilated, destroyed, lost
or stolen Escrow Receipt, a new Escrow Receipt or Escrow Receipts and of like
<PAGE>   9
                                                                               6

Escrow Interest in the Account Amounts and bearing a number not
contemporaneously outstanding.

                  In connection with the issuance of any new Escrow Receipt
under this Section 1.05, the Escrow Agent may require the payment of a sum
sufficient to cover any tax or other governmental charge that may be imposed in
relation thereto and any other expenses (including the fees and expenses of the
Pass Through Trustee and the Escrow Agent) connected therewith.

                  Any duplicate Escrow Receipt issued pursuant to this Section
1.05 shall constitute conclusive evidence of the appropriate Escrow Interest in
the Account Amounts, as if originally issued, whether or not the lost, stolen or
destroyed Escrow Receipt shall be found at any time.

                  The provisions of this Section are exclusive and shall
preclude (to the extent lawful) all other rights and remedies with respect to
the replacement or payment of mutilated, destroyed, lost or stolen Escrow
Receipts.

                  Section 1.06. Additional Escrow Amounts. On the date of any
Purchase Withdrawal, the Pass Through Trustee may re-deposit with the Depositary
some or all of the amounts so withdrawn in accordance with Section 2.4 of the
Deposit Agreement.

                  Section 1.07. Resignation or Removal of Escrow Agent. Subject
to the appointment and acceptance of a successor Escrow Agent as provided below,
the Escrow Agent may resign at any time by giving 30 days' prior written notice
thereof to the Investors, but may not otherwise be removed except for cause by
the written consent of the Investors with respect to Investors representing
Escrow Interests aggregating not less than a majority in interest in the Account
Amounts (an "Action of Investors"). Upon any such resignation or removal, the
Investors, by an Action of Investors, shall have the right to appoint a
successor Escrow Agent. If no successor Escrow Agent shall have been so
appointed and shall have accepted such appointment within 30 days after the
retiring Escrow Agent's giving of notice of resignation or the removal of the
retiring Escrow Agent, then the retiring Escrow Agent may appoint a successor
Escrow Agent. Any successor Escrow Agent shall be a bank which has an office in
the United States with a combined capital and surplus of at least $100,000,000.
Upon the acceptance of any appointment as Escrow Agent hereunder by a
<PAGE>   10
                                                                               7

successor Escrow Agent, such successor Escrow Agent shall enter into such
documents as the Pass Through Trustee shall require and shall thereupon succeed
to and become vested with all the rights, powers, privileges and duties of the
retiring Escrow Agent, and the retiring Escrow Agent shall be discharged from
its duties and obligations hereunder. No resignation or removal of the Escrow
Agent shall be effective unless a written confirmation shall have been obtained
from each of Moody's Investors Service, Inc. and Standard & Poor's Rating
Services, a division of The McGraw-Hill Companies, Inc., that the replacement of
the Escrow Agent with the successor Escrow Agent will not result in (a) a
reduction of the rating for the Certificates below the then current rating for
the Certificates or (b) a withdrawal or suspension of the rating of the
Certificates.

                  Section 1.08. Persons Deemed Owners. Prior to due presentment
of a Certificate for registration of transfer, the Escrow Agent and the Paying
Agent may treat the Person in whose name any Escrow Receipt is registered (as of
the day of determination) as the owner of such Escrow Receipt for the purpose of
receiving distributions pursuant to this Agreement and for all other purposes
whatsoever, and neither the Escrow Agent nor the Paying Agent shall be affected
by any notice to the contrary.

                  Section 1.09. Further Assurances. The Escrow Agent agrees to
take such actions, and execute such other documents, as may be reasonably
requested by the Pass Through Trustee in order to effectuate the purposes of
this Agreement and the performance by the Escrow Agent of its obligations
hereunder.

                  SECTION 2. Paying Agent.

                  Section 2.01. Appointment of Paying Agent. The Escrow Agent
hereby irrevocably appoints and authorizes the Paying Agent to act as its paying
agent hereunder, for the benefit of the Investors, for such specific purposes
and with such powers as are specifically delegated to the Paying Agent by the
terms of this Agreement, together with such other powers as are reasonably
incidental thereto. Any and all money received and held by the Paying Agent
under this Agreement or the Deposit Agreement shall be held in the Paying Agent
Account for the benefit of the Investors. The Paying Agent (which term as used
in this sentence shall include reference to its affiliates and its own and its
affiliates' officers, directors, employees and
<PAGE>   11
                                                                               8

agents): (a) shall have no duties or responsibilities except those expressly set
forth in this Agreement, and shall not by reason of this Agreement be a trustee
for the Escrow Agent; (b) shall not be responsible to the Escrow Agent for any
recitals, statements, representations or warranties of any person other then
itself contained in this Agreement or for the failure by the Escrow Agent or any
other person or entity (other than the Paying Agent) to perform any of its
obligations hereunder (whether or not the Paying Agent shall have any knowledge
thereof); and (c) except in respect of its express obligations hereunder, shall
not be responsible for any action taken or omitted to be taken by it hereunder
or provided for herein or in connection herewith, except for its own willful
misconduct or gross negligence (or simple negligence in connection with the
handling of funds).

                  Section 2.02. Establishment of Paying Agent Account. The
Paying Agent shall establish a deposit account (the "Paying Agent Account") at
Wilmington Trust Company in the name of the Escrow Agent. It is expressly
understood by the parties hereto that the Paying Agent is acting as the paying
agent of the Escrow Agent hereunder and that no amounts on deposit in the Paying
Agent Account constitute part of the Trust Property.

                  Section 2.03. Payments from Paying Agent Account. The Escrow
Agent hereby irrevocably instructs the Paying Agent, and the Paying Agent agrees
to act, as follows:

                  (a) On each Interest Payment Date (as defined in the Deposit
         Agreement) or as soon thereafter as the Paying Agent has confirmed
         receipt in the Paying Agent Account from the Depositary of any amount
         in respect of accrued interest on the Deposits, the Paying Agent shall
         distribute out of the Paying Agent Account the entire amount deposited
         therein by the Depositary. There shall be so distributed to each
         Receiptholder of record on the 15th day (whether or not a Business Day)
         preceding such Interest Payment Date by check mailed to such
         Receiptholder, at the address appearing in the Register, such
         Receiptholder's pro rata share (based on the Escrow Interest in the
         Account Amounts held by such Receiptholder) of the total amount of
         interest deposited by the Depositary in the Paying Agent Account on
         such date, except that, with respect to Escrow Receipts registered on
         the Record Date in the name of DTC, such distribution shall be made by
         wire transfer in immediately available funds to the account designated
         by DTC.
<PAGE>   12
                                                                               9

                  (b) Upon the confirmation by the Paying Agent of receipt in
         the Paying Agent Account from the Depositary of any amount in respect
         of the Final Withdrawal, the Paying Agent shall forthwith distribute
         the entire amount of the Final Withdrawal deposited therein by the
         Depositary. There shall be so distributed to each Receiptholder of
         record on the 15th day (whether or not a Business Day) preceding the
         Final Withdrawal Date by check mailed to such Receiptholder, at the
         address appearing in the Register, such Receiptholder's pro rata share
         (based on the Escrow Interest in the Account Amounts held by such
         Receiptholder) of the total amount in the Paying Agent Account on
         account of such Final Withdrawal, except that, with respect to Escrow
         Receipts registered on the Record Date in the name of DTC, such
         distribution shall be made by wire transfer in immediately available
         funds to the account designated by DTC.

                  (c) If any payment of interest or principal in respect of the
         Final Withdrawal is not received by the Paying Agent within five days
         of the applicable date when due, then it shall be distributed to
         Receiptholders after actual receipt by the Paying Agent on the same
         basis as a Special Payment is distributed under the Pass Through Trust
         Agreement.

                  (d) The Paying Agent shall include with any check mailed
         pursuant to this Section any notice required to be distributed under
         the Pass Through Trust Agreement that is furnished to the Paying Agent
         by the Pass Through Trustee.

                  Section 2.04. Withholding Taxes. The Paying Agent shall
exclude and withhold from each distribution of accrued interest on the Deposits
(as defined in the Deposit Agreement) and any amount in respect of the Final
Withdrawal any and all withholding taxes applicable thereto as required by law.
In addition, the Paying Agent shall remit or cause to be remitted such amounts
as would be required by Section 1446 of the Internal Revenue Code of 1986, as
amended, as if the agreements of the Initial Purchasers set forth in this
Agreement were characterized as a partnership engaged in a U.S. trade or
business for U.S. federal income tax purposes and shall withhold or cause to be
withheld such amounts from amounts distributable to or for the benefit of
Receiptholders or beneficial owners of interests in Escrow Receipts that are not
United States persons
<PAGE>   13
                                                                              10

within the meaning of section 7701(a)(30) of the Internal Revenue Code of 1986,
as amended ("Non-U.S. Persons"). In this regard, the Paying Agent shall cause
the appropriate withholding agent to withhold with respect to such distributions
in the manner contemplated by Section 10.04 of Revenue Procedure 89-31 and
Treasury Regulation 1.1445-8(b)(3)) by filing a notice with the National
Association of Securities Dealers, Inc. substantially in the form of Exhibits C
and D on or before the date 10 days prior to the Record Date. The Paying Agent
shall mail such notice to the National Association of Securities Dealers no
later than the date 15 days prior to the Record Date. Investors that are not
United States Persons agree to furnish a taxpayer identification number ("TIN")
to the Paying Agent and the Paying Agent shall provide such TINs to the
appropriate U.S. withholding agent. The Paying Agent agrees to act as such
withholding agent (except to the extent contemplated above with respect to
withholding amounts as if the agreements of the Initial Purchasers as set forth
in this Agreement were characterized as a business engaged in a U.S. trade or
business for U.S. federal income tax purposes) and, in connection therewith,
whenever any present or future taxes or similar charges are required to be
withheld with respect to any amounts payable in respect of the Deposits (as
defined in the Deposit Agreement) or the escrow amounts, to withhold such
amounts and timely pay the same to the appropriate authority in the name of and
on behalf of the Receiptholders, that it will file any necessary withholding tax
returns or statements when due, and that, as promptly as possible after the
payment thereof, it will deliver to each such Receiptholder appropriate
documentation showing the payment thereof, together with such additional
documentary evidence as such Receiptholder may reasonably request from time to
time. The Paying Agent agrees to file any other information reports as it may be
required to file under United States law.

                  Each Receiptholder or beneficial owner of an interest in an
Escrow Receipt that is a Non-U.S. Person, by its acceptance of an Escrow Receipt
or a beneficial interest therein, agrees to indemnify and hold harmless the
Escrow Agent and the Paying Agent from and against any improper failure to
withhold Taxes from amounts payable to it or for its benefit other than an
improper failure attributable to the gross negligence or willful misconduct of
the Escrow Agent or the Paying Agent, as the case may be.
<PAGE>   14
                                                                              11

                  Section 2.05. Resignation or Removal of Paying Agent. Subject
to the appointment and acceptance of a successor Paying Agent as provided below,
the Paying Agent may resign at any time by giving 30 days' prior written notice
thereof to the Escrow Agent, but may not otherwise be removed except for cause
by the Escrow Agent. Upon any such resignation or removal, the Escrow Agent
shall have the right to appoint a successor Paying Agent. If no successor Paying
Agent shall have been so appointed and shall have accepted such appointment
within 30 days after the retiring Paying Agent's giving of notice of resignation
or the removal of the retiring Paying Agent, then the retiring Paying Agent may
appoint a successor Paying Agent. Any Successor Paying Agent shall be a bank
which has an office in the United States with a combined capital and surplus of
at least $100,000,000. Upon the acceptance of any appointment as Paying Agent
hereunder by a successor Paying Agent, such successor Paying Agent shall enter
into such documents as the Escrow Agent shall require and shall thereupon
succeed to and become vested with all the rights, powers, privileges and duties
of the retiring Paying Agent, and the retiring Paying Agent shall be discharged
from its duties and obligations hereunder.

                  Section 2.06. Notice of Final Withdrawal. Promptly after
receipt by the Paying Agent of notice that the Escrow Agent has requested a
Final Withdrawal or that a Final Withdrawal will be made, the Paying Agent shall
cause notice of the distribution of the Final Withdrawal to be mailed to each of
the Receiptholders at its address as it appears in the Register. Such notice
shall be mailed not less than 15 days prior to the Final Withdrawal Date. Such
notice shall set forth:

                  (i) the Final Withdrawal Date and the date for determining
         Receiptholders of record who shall be entitled to receive distributions
         in respect of the Final Withdrawal,

                  (ii) the amount of the payment in respect of the Final
         Withdrawal for each $1,000 face amount Certificate (based on
         information provided by the Pass Through Trustee) and the amount
         thereof constituting unused Deposits (as defined in the Deposit
         Agreement) and interest thereon, and

                  (iii) if the Final Withdrawal Date is the same date as a
         Regular Distribution Date, the total amount to be received on such date
         for each $1,000
<PAGE>   15
                                                                              12

         face amount Certificate (based on information provided by the Pass
         Through Trustee).

                  Such mailing may include any notice required to be given to
Certificateholders in connection with such distribution pursuant to the Pass
Through Trust Agreement.

                  SECTION 3. Payments. If, notwithstanding the instructions in
Section 4 of the Deposit Agreement that all amounts payable to the Escrow Agent
under the Deposit Agreement be paid by the Depositary directly to the Paying
Agent or the Pass Through Trustee (depending on the circumstances), the Escrow
Agent receives any payment thereunder, then the Escrow Agent shall forthwith pay
such amount in Dollars and in immediately available funds by wire transfer to
(a) in the case of a payment of accrued interest on the Deposits (as defined in
the Deposit Agreement) or any Final Withdrawal, directly to the Paying Agent
Account and (b) in the case of any Purchase Withdrawal, directly to the Pass
Through Trustee or its designee as specified and in the manner provided in the
Applicable Notice of Purchase Withdrawal. The Escrow Agent hereby waives any and
all rights of set-off, combination of accounts, right of retention or similar
right (whether arising under applicable law, contract or otherwise) it may have
against amounts payable to the Paying Agent howsoever arising.

                  SECTION 4. Other Actions. The Escrow Agent shall take such
other actions under or in respect of the Deposit Agreement (including, without
limitation, the enforcement of the obligations of the Depositary thereunder) as
the Investors, by an Action of Investors, may from time to time request.

                  SECTION 5. Representations and Warranties of the Escrow Agent.
The Escrow Agent represents and warrants to America West, the Investors, the
Paying Agent and the Pass Through Trustee as follows:

                  (i) it is a banking corporation duly organized and validly
         existing in good standing under the laws of the State of Delaware;

                  (ii) it has full power, authority and legal right to conduct
         its business and operations as currently conducted and to enter into
         and perform its obligations under this Agreement and the Deposit
         Agreement;
<PAGE>   16
                                                                              13

                  (iii) the execution, delivery and performance of each of this
         Agreement and the Deposit Agreement have been duly authorized by all
         necessary corporate action on the part of it and do not require any
         stockholder approval, or approval or consent of any trustee or holder
         of any indebtedness or obligations of it, and each such document has
         been duly executed and delivered by it and constitutes its legal, valid
         and binding obligations enforceable against it in accordance with the
         terms hereof or thereof except as such enforceability may be limited by
         bankruptcy, insolvency, moratorium, reorganization or other similar
         laws or equitable principles of general application to or affecting the
         enforcement of creditors' rights generally (regardless of whether such
         enforceability is considered in a proceeding in equity or at law);

                  (iv) no authorization, consent or approval of or other action
         by, and no notice to or filing with, any United States federal or state
         governmental authority or regulatory body is required for the
         execution, delivery or performance by it of this Agreement or the
         Deposit Agreement;

                  (v) neither the execution, delivery or performance by it of
         this Agreement or the Deposit Agreement, nor compliance with the terms
         and provisions hereof or thereof, conflicts or will conflict with or
         results or will result in a breach or violation of any of the terms,
         conditions or provisions of, or will require any consent or approval
         under, any law, governmental rule or regulation or the charter
         documents, as amended, or bylaws, as amended, of it or any similar
         instrument binding on it or any order, writ, injunction or decree of
         any court or governmental authority against it or by which it or any of
         its properties is bound or any indenture, mortgage or contract or other
         agreement or instrument to which it is a party or by which it or any of
         its properties is bound, or constitutes or will constitute a default
         thereunder or results or will result in the imposition of any lien upon
         any of its properties; and
<PAGE>   17
                                                                              14

                  (vi) there are no pending or, to its knowledge, threatened
         actions, suits, investigations or proceedings (whether or not
         purportedly on behalf of it) against or affecting it or any of its
         property before or by any court or administrative agency which, if
         adversely determined, (A) would adversely affect the ability of it to
         perform its obligations under this Agreement or the Deposit Agreement
         or (B) would call into question or challenge the validity of this
         Agreement or the Deposit Agreement or the enforceability hereof or
         thereof in accordance with the terms hereof or thereof, nor is the
         Escrow Agent in default with respect to any order of any court,
         governmental authority, arbitration board or administrative agency so
         as to adversely affect its ability to perform its obligations under
         this Agreement or the Deposit Agreement.

                  SECTION 6. Representations and Warranties of the Paying Agent.
The Paying Agent represents and warrants to America West, the Investors, the
Escrow Agent and the Pass Through Trustee as follows:

                  (i) it is a banking corporation duly organized and validly
         existing in good standing under the laws of the State of Delaware;

                  (ii) it has full power, authority and legal right to conduct
         its business and operations as currently conducted and to enter into
         and perform its obligations under this Agreement;

                  (iii) the execution, delivery and performance of this
         Agreement has been duly authorized by all necessary corporate action on
         the part of it and does not require any stockholder approval, or
         approval or consent of any trustee or holder of any indebtedness or
         obligations of it, and such document has been duly executed and
         delivered by it and constitutes its legal, valid and binding
         obligations enforceable against it in accordance with the terms hereof
         except as such enforceability may be limited by bankruptcy, insolvency,
         moratorium, reorganization or other similar laws or equitable
         principles of general application to or affecting the enforcement of
         creditors' rights generally (regardless of whether
<PAGE>   18
                                                                              15

         such enforceability is considered in a proceeding in equity or at law);

                  (iv) no authorization, consent or approval of or other action
         by, and no notice to or filing with, any United States federal or state
         governmental authority or regulatory body is required for the
         execution, delivery or performance by it of this Agreement;

                  (v) neither the execution, delivery or performance by it of
         this Agreement, nor compliance with the terms and provisions hereof,
         conflicts or will conflict with or results or will result in a breach
         or violation of any of the terms, conditions or provisions of, or will
         require any consent or approval under, any law, governmental rule or
         regulation or the charter documents, as amended, or bylaws, as amended,
         of it or any similar instrument binding on it or any order, writ,
         injunction or decree of any court or governmental authority against it
         or by which it or any of its properties is bound or any indenture,
         mortgage or contract or other agreement or instrument to which it is a
         party or by which it or any of its properties is bound, or constitutes
         or will constitute a default thereunder or results or will result in
         the imposition of any lien upon any of its properties; and

                  (vi) there are no pending or, to its knowledge, threatened
         actions, suits, investigations or proceedings (whether or not
         purportedly on behalf of it) against or affecting it or any of its
         property before or by any court or administrative agency which, if
         adversely determined, (A) would adversely affect the ability of it to
         perform its obligations under this Agreement or (B) would call into
         question or challenge the validity of this Agreement or the
         enforceability hereof in accordance with the terms hereof, nor is the
         Paying Agent in default with respect to any order of any court,
         governmental authority, arbitration board or administrative agency so
         as to adversely affect its ability to perform its obligations under
         this Agreement.

                  SECTION 7. Indemnification. Except for actions expressly
required of the Escrow Agent or the Paying Agent hereunder, each of the Escrow
Agent and the Paying Agent shall
<PAGE>   19
                                                                              16

in all cases be fully justified in failing or refusing to act hereunder unless
it shall have been indemnified (both in such capacities and individually) by the
party requesting such action in a manner reasonably satisfactory to it against
any and all liability and expense which may be incurred by it by reason of
taking or continuing to take any such action. In the event America West requests
any amendment to any Operative Agreement (as defined in the Note Purchase
Agreement), the Pass Through Trustee agrees to pay all reasonable fees and
expenses (including, without limitation, fees and disbursements of counsel) of
the Escrow Agent and the Paying Agent in connection therewith.

                  SECTION 8. Amendment, Etc. Upon request of the Pass Through
Trustee and approval by an Action of Investors, the Escrow Agent shall enter
into an amendment to this Agreement, so long as such amendment does not
adversely affect the rights or obligations of the Escrow Agent or the Paying
Agent, provided that upon request of the Pass Through Trustee and without any
consent of the Investors, the Escrow Agent shall enter into an amendment to this
Agreement for any of the following purposes:

                  (1) to correct or supplement any provision in this Agreement
         which may be defective or inconsistent with any other provision herein
         or to cure any ambiguity or correct any mistake or to modify any other
         provision with respect to matters or questions arising under this
         Agreement, provided that any such action shall not materially adversely
         affect the interests of the Investors; or

                  (2) to comply with any requirement of the SEC, applicable law,
         rules or regulations of any exchange or quotation system on which the
         Certificates are listed or any regulatory body or the Registration
         Rights Agreement to effectuate the Exchange Offer; or

                  (3) to evidence and provide for the acceptance of appointment
         under this Agreement of a successor Escrow Agent, successor Paying
         Agent or successor Pass Through Trustee.

                  SECTION 9. Notices. Unless otherwise expressly provided
herein, any notice or other communication under this Agreement shall be in
writing (including by facsimile) and shall be deemed to be given and effective
upon receipt thereof (or, if received outside of business hours, on the next
open of business
<PAGE>   20
                                                                              17

on a Business Day). All notices shall be sent to (a) in the case of the
Investors, as their respective addresses shall appear in the Register, (b) in
the case of the Escrow Agent, Wilmington Trust Company, 1100 North Market
Street, Wilmington, Delaware 19890, Attention: Corporate Trust Administration
(Telecopier: 302-651-8882), (c) in the case of the Pass Through Trustee,
Wilmington Trust Company, 1100 North Market Street, Wilmington, Delaware 19890,
Attention: Corporate Trust Administration (Telecopier: 302-651-8882), or (d) in
the case of the Paying Agent, Wilmington Trust Company, 1100 North Market
Street, Wilmington, Delaware 19890, Attention: Corporate Trust Administration
(Telecopier: 302-651-8882), in each case with a copy to America West, America
West Airlines, Inc., 4000 East Sky Harbor Boulevard, Phoenix, Arizona 95043,
Attention: Vice President - Treasurer (Telecopier: (602) 693-5886) (or at such
other address as any such party may specify from time to time in a written
notice to the other parties). On or prior to the execution of this Agreement,
the Pass Through Trustee has delivered to the Escrow Agent a certificate
containing specimen signatures of the representatives of the Pass Through
Trustee who are authorized to give notices and instructions with respect to this
Agreement. The Escrow Agent may conclusively rely on such certificate until the
Escrow Agent receives written notice from the Pass Through Trustee to the
contrary.

                  SECTION 10. Transfer. No party hereto shall be entitled to
assign or otherwise transfer this Agreement (or any interest herein) other than
(in the case of the Escrow Agent) to a successor escrow agent under Section 1.06
hereof or (in the case of the Paying Agent) to a successor paying agent under
Section 2.04 hereof, and any purported assignment in violation thereof shall be
void. This Agreement shall be binding upon the parties hereto and their
respective successors and (in the case of the Escrow Agent and the Paying Agent)
their respective permitted assigns. Upon the occurrence of the Transfer (as
defined below) contemplated by the Assignment and Assumption Agreement (as
defined below), the Pass Through Trustee shall (without further act) be deemed
to have transferred all of its right, title and interest in and to this
Agreement to the trustee of the Successor Trust (as defined below) and,
thereafter, the trustee of the Successor Trust shall be deemed to be the "Pass
Through Trustee" hereunder with the rights and obligations of the "Pass Through
Trustee" hereunder and each reference herein to "America West Airlines Pass
Through Trust "1998-1B-O" shall be deemed to be a reference to "America West
Airlines Pass Through Trust 1998-1B-S". The parties hereto
<PAGE>   21
                                                                              18

hereby acknowledge and consent to the Transfer contemplated by the Assignment
and Assumption Agreement. As used herein, "Transfer" means the transfers of the
assets to the Successor Trust contemplated by the Assignment and Assumption
Agreement; "Assignment and Assumption Agreement" means the Assignment and
Assumption Agreement to be entered into between the Pass Through Trustee and the
trustee of the Successor Trust, substantially in the form of Exhibit D to the
Pass Through Trust Agreement; "Successor Trust" means the America West Airlines
Pass Through Trust 1998-1B-S.

                  SECTION 11. Entire Agreement. This Agreement sets forth all of
the promises, covenants, agreements, conditions and understandings among the
Escrow Agent, the Paying Agent, the Initial Purchasers and the Pass Through
Trustee with respect to the subject matter hereof, and supersedes all prior and
contemporaneous agreements and undertakings, inducements or conditions, express
or implied, oral or written.

                  SECTION 12. Governing Law. This Agreement shall be governed
by, and construed in accordance with, the law of the State of New York.

                  SECTION 13. Waiver of Jury Trial Right. EACH OF THE ESCROW
AGENT, THE PAYING AGENT, THE INVESTORS AND THE PASS THROUGH TRUSTEE ACKNOWLEDGES
AND ACCEPTS THAT IN ANY SUIT, ACTION OR PROCEEDING ARISING OUT OF OR RELATING TO
THIS AGREEMENT SUCH PARTY IRREVOCABLY WAIVES ITS RIGHT TO A TRIAL BY JURY.

                  SECTION 14. Counterparts. This Agreement may be executed in
one or more counterparts, all of which taken together shall constitute one
instrument.
<PAGE>   22
                                                                              19

                  IN WITNESS WHEREOF, the Escrow Agent, the Paying Agent, the
Initial Purchasers and the Pass Through Trustee have caused this Escrow and
Paying Agent Agreement (Class B) to be duly executed as of the day and year
first above written.

                                  WILMINGTON TRUST COMPANY, as Escrow Agent


                                  By   /s/ Norma P. Closs
                                      ---------------------------------------
                                       Name: Norma P. Closs
                                       Title: Vice President


                                  MORGAN STANLEY & CO. INCORPORATED,
                                  DONALDSON, LUFKIN & JENRETTE SECURITIES 
                                  CORPORATION, MERRILL LYNCH, PIERCE, FENNER &
                                  SMITH INCORPORATED and SALOMON SMITH BARNEY 
                                  INC.,
                                       as Initial Purchasers


                                  By: MORGAN STANLEY & CO.
                                         INCORPORATED


                                  By   /s/ Tom Cahill
                                       ----------------------------------------
                                       Name: Tom Cahill
                                       Title:

                                  WILMINGTON TRUST COMPANY,
                                  not in its individual
                                  capacity, but solely as
                                  Pass Through Trustee for
                                  and on behalf of America
                                  West Airlines Pass Through
                                  Trust 1998-1B-O


                                  By   /s/ James P. Lawler
                                       -----------------------------------------
                                       Name: James P. Lawler
                                       Title: Vice President
<PAGE>   23
                                                                              20

                                  WILMINGTON TRUST COMPANY,
                                  as Paying Agent


                                  By   /s/ Norma P. Closs
                                     ----------------------------
                                       Name:  Norma P. Closs
                                       Title: Vice President


<PAGE>   24
                                                                       EXHIBIT A

                  AMERICA WEST AIRLINES 1998-1B ESCROW RECEIPT

                                     No. __

                  This Escrow Receipt evidences a fractional undivided interest
in amounts ("Account Amounts") from time to time deposited into a certain paying
agent account (the "Paying Agent Account") described in the Escrow and Paying
Agent Agreement (Class B) dated as of October 6, 1998 (as amended, modified or
supplemented from time to time, the "Escrow and Paying Agent Agreement") among
Wilmington Trust Company, as Escrow Agent (in such capacity, together with its
successors in such capacity, the "Escrow Agent"), Morgan Stanley & Co.
Incorporated, Donaldson, Lufkin & Jenrette Securities Corporation , Merrill
Lynch, Pierce, Fenner & Smith Incorporated and Salomon Smith Barney Inc., as
Initial Purchasers, Wilmington Trust Company, as Pass Through Trustee (in such
capacity, together with its successors in such capacity, the "Pass Through
Trustee") and Wilmington Trust Company, as paying agent (in such capacity,
together with its successors in such capacity, the "Paying Agent"). Capitalized
terms not defined herein shall have the meanings assigned to them in the Escrow
and Paying Agent Agreement.

                  This Escrow Receipt is issued under and is subject to the
terms, provisions and conditions of the Escrow and Paying Agent Agreement. By
virtue of its acceptance hereof the holder of this Escrow Receipt assents and
agrees to be bound by the provisions of the Escrow and Paying Agent Agreement
and this Escrow Receipt.

                  This Escrow Receipt represents a fractional undivided interest
in amounts deposited from time to time in the Paying Agent Account, and grants
or represents no rights, benefits or interests of any kind in respect of any
assets or property other than such amounts. This Escrow Receipt evidences the
same percentage interest in the Account Amounts as the Fractional Undivided
Interest in the Pass Through Trust evidenced by the Certificate to which this
Escrow Receipt is affixed.

                  All payments and distributions made to Receiptholders in
respect of the Escrow Receipt shall be made only from Account Amounts deposited
in the Paying Agent Account. The holder of this Escrow Receipt, by its
acceptance of this Escrow Receipt, agrees that it will look solely to the
Account Amounts for any payment or distribution due to it pursuant to this
Escrow
<PAGE>   25
                                                                               2

Receipt and that it will not have any recourse to America West, the Pass Through
Trustee, the Paying Agent or the Escrow Agent, except as expressly provided
herein or in the Pass Through Trust Agreement. No Receiptholder of this Escrow
Receipt shall have any right to vote or in any manner otherwise control the
operation and management of the Paying Agent Account, nor shall anything set
forth herein, or contained in the terms of this Escrow Receipt, be construed so
as to constitute the Receiptholders from time to time as partners or members of
an association.

                  This Escrow Receipt may not be assigned or transferred except
in connection with the assignment or transfer of the Certificate to which this
Escrow Receipt is affixed. After payment to the holder hereof of its Escrow
Interest in the Final Distribution, upon the request of the Pass Through
Trustee, the holder hereof will return this Escrow Receipt to the Pass Through
Trustee.

                  The Paying Agent may treat the person in whose name the
Certificate to which this Escrow Receipt is attached as the owner hereof for all
purposes, and the Paying Agent shall not be affected by any notice to the
contrary.

                  THIS ESCROW RECEIPT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAW OF THE STATE OF NEW YORK.

                  IN WITNESS WHEREOF, the Escrow Agent has caused this Escrow
Receipt to be duly executed.

Dated: ______________, 199_

                                           WILMINGTON TRUST COMPANY,
                                           as Escrow Agent

                                           By   _______________________________
                                                Name:
                                                Title:
<PAGE>   26
                                                                       EXHIBIT B

                             WITHDRAWAL CERTIFICATE
                                    (Class B)

                            WILMINGTON TRUST COMPANY,
                                 as Escrow Agent

Dear Sirs:

                  Reference is made to the Escrow and Paying Agent Agreement,
dated as of October 6, 1998 (the "Agreement"). We hereby certify to you that the
conditions to the obligations of the undersigned to execute a Participation
Agreement pursuant to the Note Purchase Agreement have been satisfied. Pursuant
to Section 1.02(c) of the Agreement, please execute the attached Notice of
Withdrawal and immediately transmit by facsimile to the Depositary, at (312)
606-8428, Attention: Vice President - Aerospace.

                                       Very truly yours,

                                       WILMINGTON TRUST COMPANY,
                                       not in its individual capacity but
                                       solely as Pass Through Trustee


                                       By   ___________________________________
                                            Name:
                                            Title:



Dated:  ____________, 199_

<PAGE>   1
                                                                    EXHIBIT 4.20


                                                                       EXECUTION




                        ESCROW AND PAYING AGENT AGREEMENT
                                    (Class C)

                           Dated as of October 6, 1998

                                      among

                            WILMINGTON TRUST COMPANY
                                 as Escrow Agent

                       MORGAN STANLEY & CO. INCORPORATED,
               DONALDSON, LUFKIN & JENRETTE SECURITIES CORPORATION
               MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED
                                       and
                            SALOMON SMITH BARNEY INC.

                              as Initial Purchasers

                            WILMINGTON TRUST COMPANY,
                         not in its individual capacity,
                       but solely as Pass Through Trustee
                              for and on behalf of
               America West Airlines Pass Through Trust 1998-1C-O

                             as Pass Through Trustee

                                       and

                            WILMINGTON TRUST COMPANY

                                 as Paying Agent
<PAGE>   2
                                TABLE OF CONTENTS

                                                                            Page

SECTION 1.        Escrow Agent.................................................2


Section 1.01.     Appointment of Escrow Agent..................................2


Section 1.02.     Instruction; Etc.............................................3


Section 1.03.     Initial Escrow Amount; Issuance of Escrow
                  Receipts.....................................................4


Section 1.04.     Payments to Receiptholders...................................5


Section 1.05.     Mutilated, Destroyed, Lost or Stolen Escrow Receipt..........5


Section 1.06.     Additional Escrow Amounts....................................6


Section 1.07.     Resignation or Removal of Escrow Agent.......................6


Section 1.08.     Persons Deemed Owners........................................7


Section 1.09.     Further Assurances...........................................7


SECTION 2.        Paying Agent.................................................7


Section 2.01.     Appointment of Paying Agent..................................7


Section 2.02.     Establishment of Paying Agent Account........................8


Section 2.03.     Payments from Paying Agent Account...........................8


Section 2.04.     Withholding Taxes............................................9


Section 2.05.     Resignation or Removal of Paying Agent......................11


                                        i
<PAGE>   3
                                                                            Page

Section 2.06.     Notice of Final Withdrawal..................................11


SECTION 3.        Payments....................................................12


SECTION 4.        Other Actions...............................................12


SECTION 5.        Representations and Warranties of the
                  Escrow Agent................................................12


SECTION 6.        Representations and Warranties of the
                  Paying Agent................................................14


SECTION 7.        Indemnification.............................................15


SECTION 8.        Amendment, Etc..............................................16


SECTION 9.        Notices.....................................................16


SECTION 10.       Transfer....................................................17


SECTION 11.       Entire Agreement............................................18


SECTION 12.       Governing Law...............................................18


SECTION 13.       Waiver of Jury Trial Right..................................18


SECTION 14.       Counterparts................................................18



Exhibit A         Escrow Receipt

Exhibit B         Withdrawal Certificate


                                       ii
<PAGE>   4
            ESCROW AND PAYING AGENT AGREEMENT (Class C) dated as of October 6,
1998 (as amended, modified or supplemented from time to time, this "Agreement")
among WILMINGTON TRUST COMPANY, a Delaware banking corporation, as Escrow Agent
(in such capacity, together with its successors in such capacity, the "Escrow
Agent"); MORGAN STANLEY & CO. INCORPORATED, DONALDSON, LUFKIN & JENRETTE
SECURITIES CORPORATION, MERRILL LYNCH, PIERCE, FENNER & SMITH INCORPORATED and
SALOMON SMITH BARNEY INC., as Initial Purchasers of the Certificates referred to
below (the "Initial Purchasers" and together with their respective transferees
and assigns as registered owners of the Certificates, the "Investors") under the
Purchase Agreement referred to below; Wilmington Trust Company, a Delaware
banking corporation, not in its individual capacity except as otherwise
expressly provided herein, but solely as trustee (in such capacity, together
with its successors in such capacity, the "Pass Through Trustee") under the Pass
Through Trust Agreement referred to below; and WILMINGTON TRUST COMPANY, a
Delaware banking corporation, as paying agent hereunder (in such capacity,
together with its successors in such capacity, the "Paying Agent").

                               W I T N E S S E T H

            WHEREAS, America West Airlines, Inc. ("America West") and the Pass
Through Trustee have entered into a Pass Through Trust Agreement, dated as of
October 6, 1998 (together, as amended, modified or supplemented from time to
time in accordance with the terms thereof, the "Pass Through Trust Agreement")
relating to America West Airlines Pass Through Trust 1998-1C-O (the "Pass
Through Trust") pursuant to which the America West Airlines Pass Through Trust,
Series 1998-1C-O Certificates referred to therein (the "Certificates") are being
issued;

            WHEREAS, America West and the Initial Purchasers have entered into a
Purchase Agreement dated as of September 24, 1998 (as amended, modified or
supplemented from time to time in accordance with the terms thereof, the
"Purchase Agreement") pursuant to which the Pass Through Trustee will issue and
sell the Certificates to the Initial Purchasers (the net proceeds of such sale
being herein referred to as the "Net Proceeds");

            WHEREAS, America West, the Pass Through Trustee, certain other pass
through trustees and certain other persons concurrently herewith are entering
into the Note Purchase Agreement, dated as of the date hereof (the "Note
Purchase 
<PAGE>   5
                                                                               2


Agreement"), pursuant to which the Pass Through Trustee has agreed to acquire
from time to time on or prior to the Delivery Period Termination Date (as
defined in the Note Purchase Agreement) equipment notes (the "Equipment Notes")
issued to finance or refinance the acquisition of aircraft by America West, as
lessee or as owner, utilizing a portion of the Net Proceeds;

            WHEREAS, the Initial Purchasers and the Pass Through Trustee intend
that the Net Proceeds be held in escrow by the Escrow Agent on behalf of the
Investors, subject to withdrawal upon request by the Pass Through Trustee and
satisfaction of the conditions set forth in the Note Purchase Agreement for the
purpose of purchasing Equipment Notes, and that pending such withdrawal the Net
Proceeds be deposited on behalf of the Escrow Agent with ABN AMRO Bank N.V.,
acting through its Chicago branch, as Depositary (the "Depositary") under the
Deposit Agreement, dated as of the date hereof between the Depositary and the
Escrow Agent relating to the Pass Through Trust (as amended, modified or
supplemented from time to time in accordance with the terms thereof, the
"Deposit Agreement") pursuant to which, among other things, the Depositary will
pay interest for distribution to the Investors and establish accounts from which
the Escrow Agent shall make withdrawals upon request of and proper certification
by the Pass Through Trustee;

            WHEREAS, the Escrow Agent wishes to appoint the Paying Agent to pay
amounts required to be distributed to the Investors in accordance with this
Agreement; and

            WHEREAS, capitalized terms used but not defined herein shall have
the meanings ascribed to such terms in the Pass Through Trust Agreement.

            NOW, THEREFORE, in consideration of the obligations contained
herein, and for other good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the parties hereto hereby agree as
follows:

            SECTION 1. Escrow Agent.


            Section 1.01. Appointment of Escrow Agent. Each of the Initial
Purchasers, for and on behalf of each of the Investors, hereby irrevocably
appoints, authorizes and directs the Escrow Agent to act as escrow agent and
fiduciary hereunder and under the Deposit Agreement for such specific purposes
and 
<PAGE>   6
                                                                               3


with such powers as are specifically delegated to the Escrow Agent by the terms
of this Agreement, together with such other powers as are reasonably incidental
thereto. Any and all money received and held by the Escrow Agent under this
Agreement or the Deposit Agreement shall be held in escrow by the Escrow Agent
in accordance with the terms of this Agreement. This Agreement is irrevocable
and the Investors' rights with respect to any monies received and held in escrow
by the Escrow Agent under this Agreement or the Deposit Agreement shall only be
as provided under the terms and conditions of this Agreement and the Deposit
Agreement. The Escrow Agent (which term as used in this sentence shall include
reference to its affiliates and its own and its affiliates' officers, directors,
employees and agents): (a) shall have no duties or responsibilities except those
expressly set forth in this Agreement; (b) shall not be responsible to the Pass
Through Trustee or the Investors for any recitals, statements, representations
or warranties of any person other then itself contained in this Agreement or the
Deposit Agreement or for the failure by the Pass Through Trustee, the Investors
or any other person or entity (other than the Escrow Agent) to perform any of
its obligations hereunder (whether or not the Escrow Agent shall have any
knowledge thereof); and (c) shall not be responsible for any action taken or
omitted to be taken by it hereunder or provided for herein or in connection
herewith, except for its own willful misconduct or gross negligence (or simple
negligence in connection with the handling of funds) or breach of its
obligations hereunder.

            Section 1.02. Instruction; Etc. The Initial Purchasers, for and on
behalf of each of the Investors, hereby irrevocably instruct the Escrow Agent,
and the Escrow Agent agrees, (a) to enter into the Deposit Agreement, (b) to
appoint the Paying Agent as provided in this Agreement, (c) upon receipt at any
time and from time to time prior to the Termination Date (as defined below) of a
certificate substantially in the form of Exhibit B hereto (a "Withdrawal
Certificate") executed by the Pass Through Trustee, together with an attached
Notice of Purchase Withdrawal in substantially the form of Exhibit A to the
Deposit Agreement duly completed by the Pass Through Trustee (the "Applicable
Notice of Purchase Withdrawal" and the withdrawal to which it relates, a
"Purchase Withdrawal"), immediately to execute the Applicable Notice of Purchase
Withdrawal as Escrow Agent and transmit it to the Depositary by facsimile
transmission in accordance with the Deposit Agreement; provided that, upon the
request of the Pass Through Trustee after such transmission, the Escrow Agent
shall cancel such 
<PAGE>   7
                                                                               4


Applicable Notice of Purchase Withdrawal, and (d) if there are any undrawn
Deposits (as defined in the Deposit Agreement) on the "Termination Date", which
shall mean the earlier of (i) February 1, 2000 and (ii) the day on which the
Escrow Agent receives notice from the Pass Through Trustee that the Pass Through
Trustee's obligation to purchase Equipment Notes under the Note Purchase
Agreement has terminated, to give notice to the Depositary (with a copy to the
Paying Agent) substantially in the form of Exhibit B to the Deposit Agreement
requesting a withdrawal of all of the remaining Deposits, together with accrued
and unpaid interest on such Deposits to the date of withdrawal, on the 35th day
after the date that such notice of withdrawal is given to the Depositary (or, if
not a Business Day, on the next succeeding Business Day) (a "Final Withdrawal"),
provided that if the day scheduled for the Final Withdrawal in accordance with
the foregoing is within 10 days before or after a Regular Distribution Date,
then the Escrow Agent shall request that such requested Final Withdrawal be made
on such Regular Distribution Date (the date of such requested withdrawal, the
"Final Withdrawal Date"). If for any reason the Escrow Agent shall have failed
to give the Final Withdrawal Notice to the Depositary on or before February 7,
2000, and there are unwithdrawn Deposits on such date, the Final Withdrawal Date
shall be deemed to be February 28, 2000.

            Section 1.03. Initial Escrow Amount; Issuance of Escrow Receipts.
The Escrow Agent hereby directs the Initial Purchasers to, and the Initial
Purchasers hereby acknowledge that on the date hereof they shall, irrevocably
deliver to the Depositary on behalf of the Escrow Agent, an amount in U.S.
dollars ("Dollars") and immediately available funds equal to $17,705,000 for
deposit on behalf of the Escrow Agent with the Depositary in accordance with
Section 2.1 of the Deposit Agreement. The Initial Purchasers hereby instruct the
Escrow Agent, upon receipt of such sum from the Initial Purchasers, to confirm
such receipt by executing and delivering to the Pass Through Trustee an Escrow
Receipt in the form of Exhibit A hereto (an "Escrow Receipt"), (a) to be affixed
by the Pass Through Trustee to each Certificate and (b) to evidence the same
percentage interest (the "Escrow Interest") in the Account Amounts (as defined
below) as the Fractional Undivided Interest in the Pass Through Trust evidenced
by the Certificate to which it is to be affixed. The Escrow Agent shall provide
to the Pass Through Trustee for attachment to each Certificate newly issued
under and in accordance with the Pass Through Trust Agreement an executed Escrow
Receipt as the Pass Through Trustee may from 
<PAGE>   8
                                                                               5


time to time request of the Escrow Agent. Each Escrow Receipt shall be
registered by the Escrow Agent in a register (the "Register") maintained by the
Escrow Agent in the same name and same manner as the Certificate to which it is
attached and may not thereafter be detached from such Certificate to which it is
to be affixed prior to the distribution of the Final Withdrawal (the "Final
Distribution"). After the Final Distribution, no additional Escrow Receipts
shall be issued and the Pass Through Trustee shall request the return to the
Escrow Agent for cancellation of all outstanding Escrow Receipts.

            Section 1.04. Payments to Receiptholders. All payments and
distributions made to holders of an Escrow Receipt (collectively
"Receiptholders") in respect of the Escrow Receipt shall be made only from
amounts deposited in the Paying Agent Account (as defined below) ("Account
Amounts"). Each Receiptholder, by its acceptance of an Escrow Receipt, agrees
that (a) it will look solely to the Account Amounts for any payment or
distribution due to such Receiptholder pursuant to the terms of the Escrow
Receipt and this Agreement and (b) it will have no recourse to America West, the
Pass Through Trustee, the Paying Agent, the Escrow Agent or Wilmington Trust
Company, except as expressly provided herein or in the Pass Through Trust
Agreement. No Receiptholder shall have any right to vote or in any manner
otherwise control the operation and management of the Paying Agent Account or
the obligations of the parties hereto, nor shall anything set forth herein, or
contained in the terms of the Escrow Receipt, be construed so as to constitute
the Receiptholders from time to time as partners or members of an association.

            Section 1.05. Mutilated, Destroyed, Lost or Stolen Escrow Receipt.
If (a) any mutilated Escrow Receipt is surrendered to the Escrow Agent or the
Escrow Agent receives evidence to its satisfaction of the destruction, loss or
theft of any Escrow Receipt and (b) there is delivered to the Escrow Agent and
the Pass Through Trustee such security, indemnity or bond, as may be required by
them to hold each of them harmless, then, absent notice to the Escrow Agent or
the Pass Through Trustee that such destroyed, lost or stolen Escrow Receipt has
been acquired by a bona fide purchaser, and provided that the requirements of
Section 8-405 of the Uniform Commercial Code in effect in any applicable
jurisdiction are met, the Escrow Agent shall execute, authenticate and deliver,
in exchange for or in lieu of any such mutilated, destroyed, lost or stolen
Escrow Receipt, a new Escrow Receipt or Escrow Receipts and of like 
<PAGE>   9
                                                                               6


Escrow Interest in the Account Amounts and bearing a number not
contemporaneously outstanding.

            In connection with the issuance of any new Escrow Receipt under this
Section 1.05, the Escrow Agent may require the payment of a sum sufficient to
cover any tax or other governmental charge that may be imposed in relation
thereto and any other expenses (including the fees and expenses of the Pass
Through Trustee and the Escrow Agent) connected therewith.

            Any duplicate Escrow Receipt issued pursuant to this Section 1.05
shall constitute conclusive evidence of the appropriate Escrow Interest in the
Account Amounts, as if originally issued, whether or not the lost, stolen or
destroyed Escrow Receipt shall be found at any time.

            The provisions of this Section are exclusive and shall preclude (to
the extent lawful) all other rights and remedies with respect to the replacement
or payment of mutilated, destroyed, lost or stolen Escrow Receipts.

            Section 1.06. Additional Escrow Amounts. On the date of any Purchase
Withdrawal, the Pass Through Trustee may re-deposit with the Depositary some or
all of the amounts so withdrawn in accordance with Section 2.4 of the Deposit
Agreement.

            Section 1.07. Resignation or Removal of Escrow Agent. Subject to the
appointment and acceptance of a successor Escrow Agent as provided below, the
Escrow Agent may resign at any time by giving 30 days' prior written notice
thereof to the Investors, but may not otherwise be removed except for cause by
the written consent of the Investors with respect to Investors representing
Escrow Interests aggregating not less than a majority in interest in the Account
Amounts (an "Action of Investors"). Upon any such resignation or removal, the
Investors, by an Action of Investors, shall have the right to appoint a
successor Escrow Agent. If no successor Escrow Agent shall have been so
appointed and shall have accepted such appointment within 30 days after the
retiring Escrow Agent's giving of notice of resignation or the removal of the
retiring Escrow Agent, then the retiring Escrow Agent may appoint a successor
Escrow Agent. Any successor Escrow Agent shall be a bank which has an office in
the United States with a combined capital and surplus of at least $100,000,000.
Upon the acceptance of any appointment as Escrow Agent hereunder by a 
<PAGE>   10
                                                                               7


successor Escrow Agent, such successor Escrow Agent shall enter into such
documents as the Pass Through Trustee shall require and shall thereupon succeed
to and become vested with all the rights, powers, privileges and duties of the
retiring Escrow Agent, and the retiring Escrow Agent shall be discharged from
its duties and obligations hereunder. No resignation or removal of the Escrow
Agent shall be effective unless a written confirmation shall have been obtained
from each of Moody's Investors Service, Inc. and Standard & Poor's Rating
Services, a division of The McGraw-Hill Companies, Inc., that the replacement of
the Escrow Agent with the successor Escrow Agent will not result in (a) a
reduction of the rating for the Certificates below the then current rating for
the Certificates or (b) a withdrawal or suspension of the rating of the
Certificates.

            Section 1.08. Persons Deemed Owners. Prior to due presentment of a
Certificate for registration of transfer, the Escrow Agent and the Paying Agent
may treat the Person in whose name any Escrow Receipt is registered (as of the
day of determination) as the owner of such Escrow Receipt for the purpose of
receiving distributions pursuant to this Agreement and for all other purposes
whatsoever, and neither the Escrow Agent nor the Paying Agent shall be affected
by any notice to the contrary.

            Section 1.09. Further Assurances. The Escrow Agent agrees to take
such actions, and execute such other documents, as may be reasonably requested
by the Pass Through Trustee in order to effectuate the purposes of this
Agreement and the performance by the Escrow Agent of its obligations hereunder.

            SECTION 2. Paying Agent.


            Section 2.01. Appointment of Paying Agent. The Escrow Agent hereby
irrevocably appoints and authorizes the Paying Agent to act as its paying agent
hereunder, for the benefit of the Investors, for such specific purposes and with
such powers as are specifically delegated to the Paying Agent by the terms of
this Agreement, together with such other powers as are reasonably incidental
thereto. Any and all money received and held by the Paying Agent under this
Agreement or the Deposit Agreement shall be held in the Paying Agent Account for
the benefit of the Investors. The Paying Agent (which term as used in this
sentence shall include reference to its affiliates and its own and its
affiliates' officers, directors, employees and 
<PAGE>   11
                                                                               8


agents): (a) shall have no duties or responsibilities except those expressly set
forth in this Agreement, and shall not by reason of this Agreement be a trustee
for the Escrow Agent; (b) shall not be responsible to the Escrow Agent for any
recitals, statements, representations or warranties of any person other then
itself contained in this Agreement or for the failure by the Escrow Agent or any
other person or entity (other than the Paying Agent) to perform any of its
obligations hereunder (whether or not the Paying Agent shall have any knowledge
thereof); and (c) except in respect of its express obligations hereunder, shall
not be responsible for any action taken or omitted to be taken by it hereunder
or provided for herein or in connection herewith, except for its own willful
misconduct or gross negligence (or simple negligence in connection with the
handling of funds).

            Section 2.02. Establishment of Paying Agent Account. The Paying
Agent shall establish a deposit account (the "Paying Agent Account") at
Wilmington Trust Company in the name of the Escrow Agent. It is expressly
understood by the parties hereto that the Paying Agent is acting as the paying
agent of the Escrow Agent hereunder and that no amounts on deposit in the Paying
Agent Account constitute part of the Trust Property.

            Section 2.03. Payments from Paying Agent Account. The Escrow Agent
hereby irrevocably instructs the Paying Agent, and the Paying Agent agrees to
act, as follows:

            (a) On each Interest Payment Date (as defined in the Deposit
      Agreement) or as soon thereafter as the Paying Agent has confirmed receipt
      in the Paying Agent Account from the Depositary of any amount in respect
      of accrued interest on the Deposits, the Paying Agent shall distribute out
      of the Paying Agent Account the entire amount deposited therein by the
      Depositary. There shall be so distributed to each Receiptholder of record
      on the 15th day (whether or not a Business Day) preceding such Interest
      Payment Date by check mailed to such Receiptholder, at the address
      appearing in the Register, such Receiptholder's pro rata share (based on
      the Escrow Interest in the Account Amounts held by such Receiptholder) of
      the total amount of interest deposited by the Depositary in the Paying
      Agent Account on such date, except that, with respect to Escrow Receipts
      registered on the Record Date in the name of DTC, such distribution shall
      be made by wire transfer in immediately available funds to the account
      designated by DTC.
<PAGE>   12
                                                                               9


            (b) Upon the confirmation by the Paying Agent of receipt in the
      Paying Agent Account from the Depositary of any amount in respect of the
      Final Withdrawal, the Paying Agent shall forthwith distribute the entire
      amount of the Final Withdrawal deposited therein by the Depositary. There
      shall be so distributed to each Receiptholder of record on the 15th day
      (whether or not a Business Day) preceding the Final Withdrawal Date by
      check mailed to such Receiptholder, at the address appearing in the
      Register, such Receiptholder's pro rata share (based on the Escrow
      Interest in the Account Amounts held by such Receiptholder) of the total
      amount in the Paying Agent Account on account of such Final Withdrawal,
      except that, with respect to Escrow Receipts registered on the Record Date
      in the name of DTC, such distribution shall be made by wire transfer in
      immediately available funds to the account designated by DTC.

            (c) If any payment of interest or principal in respect of the Final
      Withdrawal is not received by the Paying Agent within five days of the
      applicable date when due, then it shall be distributed to Receiptholders
      after actual receipt by the Paying Agent on the same basis as a Special
      Payment is distributed under the Pass Through Trust Agreement.

            (d) The Paying Agent shall include with any check mailed pursuant to
      this Section any notice required to be distributed under the Pass Through
      Trust Agreement that is furnished to the Paying Agent by the Pass Through
      Trustee.

            Section 2.04. Withholding Taxes. The Paying Agent shall exclude and
withhold from each distribution of accrued interest on the Deposits (as defined
in the Deposit Agreement) and any amount in respect of the Final Withdrawal any
and all withholding taxes applicable thereto as required by law. In addition,
the Paying Agent shall remit or cause to be remitted such amounts as would be
required by Section 1446 of the Internal Revenue Code of 1986, as amended, as if
the agreements of the Initial Purchasers set forth in this Agreement were
characterized as a partnership engaged in a U.S. trade or business for U.S.
federal income tax purposes and shall withhold or cause to be withheld such
amounts from amounts distributable to or for the benefit of Receiptholders or
beneficial owners of interests in Escrow Receipts that are not United States
persons 
<PAGE>   13
                                                                              10


within the meaning of section 7701(a)(30) of the Internal Revenue Code of 1986,
as amended ("Non-U.S. Persons"). In this regard, the Paying Agent shall cause
the appropriate withholding agent to withhold with respect to such distributions
in the manner contemplated by Section 10.04 of Revenue Procedure 89-31 and
Treasury Regulation 1.1445-8(b)(3)) by filing a notice with the National
Association of Securities Dealers, Inc. substantially in the form of Exhibits C
and D on or before the date 10 days prior to the Record Date. The Paying Agent
shall mail such notice to the National Association of Securities Dealers no
later than the date 15 days prior to the Record Date. Investors that are not
United States Persons agree to furnish a taxpayer identification number ("TIN")
to the Paying Agent and the Paying Agent shall provide such TINs to the
appropriate U.S. withholding agent. The Paying Agent agrees to act as such
withholding agent (except to the extent contemplated above with respect to
withholding amounts as if the agreements of the Initial Purchasers as set forth
in this Agreement were characterized as a business engaged in a U.S. trade or
business for U.S. federal income tax purposes) and, in connection therewith,
whenever any present or future taxes or similar charges are required to be
withheld with respect to any amounts payable in respect of the Deposits (as
defined in the Deposit Agreement) or the escrow amounts, to withhold such
amounts and timely pay the same to the appropriate authority in the name of and
on behalf of the Receiptholders, that it will file any necessary withholding tax
returns or statements when due, and that, as promptly as possible after the
payment thereof, it will deliver to each such Receiptholder appropriate
documentation showing the payment thereof, together with such additional
documentary evidence as such Receiptholder may reasonably request from time to
time. The Paying Agent agrees to file any other information reports as it may be
required to file under United States law.

            Each Receiptholder or beneficial owner of an interest in an Escrow
Receipt that is a Non-U.S. Person, by its acceptance of an Escrow Receipt or a
beneficial interest therein, agrees to indemnify and hold harmless the Escrow
Agent and the Paying Agent from and against any improper failure to withhold
Taxes from amounts payable to it or for its benefit other than an improper
failure attributable to the gross negligence or willful misconduct of the Escrow
Agent or the Paying Agent, as the case may be.
<PAGE>   14
                                                                              11


            Section 2.05. Resignation or Removal of Paying Agent. Subject to the
appointment and acceptance of a successor Paying Agent as provided below, the
Paying Agent may resign at any time by giving 30 days' prior written notice
thereof to the Escrow Agent, but may not otherwise be removed except for cause
by the Escrow Agent. Upon any such resignation or removal, the Escrow Agent
shall have the right to appoint a successor Paying Agent. If no successor Paying
Agent shall have been so appointed and shall have accepted such appointment
within 30 days after the retiring Paying Agent's giving of notice of resignation
or the removal of the retiring Paying Agent, then the retiring Paying Agent may
appoint a successor Paying Agent. Any Successor Paying Agent shall be a bank
which has an office in the United States with a combined capital and surplus of
at least $100,000,000. Upon the acceptance of any appointment as Paying Agent
hereunder by a successor Paying Agent, such successor Paying Agent shall enter
into such documents as the Escrow Agent shall require and shall thereupon
succeed to and become vested with all the rights, powers, privileges and duties
of the retiring Paying Agent, and the retiring Paying Agent shall be discharged
from its duties and obligations hereunder.

            Section 2.06. Notice of Final Withdrawal. Promptly after receipt by
the Paying Agent of notice that the Escrow Agent has requested a Final
Withdrawal or that a Final Withdrawal will be made, the Paying Agent shall cause
notice of the distribution of the Final Withdrawal to be mailed to each of the
Receiptholders at its address as it appears in the Register. Such notice shall
be mailed not less than 15 days prior to the Final Withdrawal Date. Such notice
shall set forth:

            (i) the Final Withdrawal Date and the date for determining
      Receiptholders of record who shall be entitled to receive distributions in
      respect of the Final Withdrawal,

            (ii) the amount of the payment in respect of the Final Withdrawal
      for each $1,000 face amount Certificate (based on information provided by
      the Pass Through Trustee) and the amount thereof constituting unused
      Deposits (as defined in the Deposit Agreement) and interest thereon, and

            (iii) if the Final Withdrawal Date is the same date as a Regular
      Distribution Date, the total amount to be received on such date for each
      $1,000 
<PAGE>   15
                                                                              12


      face amount Certificate (based on information provided by the Pass Through
      Trustee).

            Such mailing may include any notice required to be given to
Certificateholders in connection with such distribution pursuant to the Pass
Through Trust Agreement.

            SECTION 3. Payments. If, notwithstanding the instructions in Section
4 of the Deposit Agreement that all amounts payable to the Escrow Agent under
the Deposit Agreement be paid by the Depositary directly to the Paying Agent or
the Pass Through Trustee (depending on the circumstances), the Escrow Agent
receives any payment thereunder, then the Escrow Agent shall forthwith pay such
amount in Dollars and in immediately available funds by wire transfer to (a) in
the case of a payment of accrued interest on the Deposits (as defined in the
Deposit Agreement) or any Final Withdrawal, directly to the Paying Agent Account
and (b) in the case of any Purchase Withdrawal, directly to the Pass Through
Trustee or its designee as specified and in the manner provided in the
Applicable Notice of Purchase Withdrawal. The Escrow Agent hereby waives any and
all rights of set-off, combination of accounts, right of retention or similar
right (whether arising under applicable law, contract or otherwise) it may have
against amounts payable to the Paying Agent howsoever arising.

            SECTION 4. Other Actions. The Escrow Agent shall take such other
actions under or in respect of the Deposit Agreement (including, without
limitation, the enforcement of the obligations of the Depositary thereunder) as
the Investors, by an Action of Investors, may from time to time request.

            SECTION 5. Representations and Warranties of the Escrow Agent. The
Escrow Agent represents and warrants to America West, the Investors, the Paying
Agent and the Pass Through Trustee as follows:

            (i) it is a banking corporation duly organized and validly existing
      in good standing under the laws of the State of Delaware;

            (ii) it has full power, authority and legal right to conduct its
      business and operations as currently conducted and to enter into and
      perform its obligations under this Agreement and the Deposit Agreement;
<PAGE>   16
                                                                              13


            (iii) the execution, delivery and performance of each of this
      Agreement and the Deposit Agreement have been duly authorized by all
      necessary corporate action on the part of it and do not require any
      stockholder approval, or approval or consent of any trustee or holder of
      any indebtedness or obligations of it, and each such document has been
      duly executed and delivered by it and constitutes its legal, valid and
      binding obligations enforceable against it in accordance with the terms
      hereof or thereof except as such enforceability may be limited by
      bankruptcy, insolvency, moratorium, reorganization or other similar laws
      or equitable principles of general application to or affecting the
      enforcement of creditors' rights generally (regardless of whether such
      enforceability is considered in a proceeding in equity or at law);

            (iv) no authorization, consent or approval of or other action by,
      and no notice to or filing with, any United States federal or state
      governmental authority or regulatory body is required for the execution,
      delivery or performance by it of this Agreement or the Deposit Agreement;

            (v) neither the execution, delivery or performance by it of this
      Agreement or the Deposit Agreement, nor compliance with the terms and
      provisions hereof or thereof, conflicts or will conflict with or results
      or will result in a breach or violation of any of the terms, conditions or
      provisions of, or will require any consent or approval under, any law,
      governmental rule or regulation or the charter documents, as amended, or
      bylaws, as amended, of it or any similar instrument binding on it or any
      order, writ, injunction or decree of any court or governmental authority
      against it or by which it or any of its properties is bound or any
      indenture, mortgage or contract or other agreement or instrument to which
      it is a party or by which it or any of its properties is bound, or
      constitutes or will constitute a default thereunder or results or will
      result in the imposition of any lien upon any of its properties; and
<PAGE>   17
                                                                              14


            (vi) there are no pending or, to its knowledge, threatened actions,
      suits, investigations or proceedings (whether or not purportedly on behalf
      of it) against or affecting it or any of its property before or by any
      court or administrative agency which, if adversely determined, (A) would
      adversely affect the ability of it to perform its obligations under this
      Agreement or the Deposit Agreement or (B) would call into question or
      challenge the validity of this Agreement or the Deposit Agreement or the
      enforceability hereof or thereof in accordance with the terms hereof or
      thereof, nor is the Escrow Agent in default with respect to any order of
      any court, governmental authority, arbitration board or administrative
      agency so as to adversely affect its ability to perform its obligations
      under this Agreement or the Deposit Agreement.

            SECTION 6. Representations and Warranties of the Paying Agent. The
Paying Agent represents and warrants to America West, the Investors, the Escrow
Agent and the Pass Through Trustee as follows:

            (i) it is a banking corporation duly organized and validly existing
      in good standing under the laws of the State of Delaware;

            (ii) it has full power, authority and legal right to conduct its
      business and operations as currently conducted and to enter into and
      perform its obligations under this Agreement;

            (iii) the execution, delivery and performance of this Agreement has
      been duly authorized by all necessary corporate action on the part of it
      and does not require any stockholder approval, or approval or consent of
      any trustee or holder of any indebtedness or obligations of it, and such
      document has been duly executed and delivered by it and constitutes its
      legal, valid and binding obligations enforceable against it in accordance
      with the terms hereof except as such enforceability may be limited by
      bankruptcy, insolvency, moratorium, reorganization or other similar laws
      or equitable principles of general application to or affecting the
      enforcement of creditors' rights generally (regardless of whether 
<PAGE>   18
                                                                              15


      such enforceability is considered in a proceeding in equity or at law);

            (iv) no authorization, consent or approval of or other action by,
      and no notice to or filing with, any United States federal or state
      governmental authority or regulatory body is required for the execution,
      delivery or performance by it of this Agreement;

            (v) neither the execution, delivery or performance by it of this
      Agreement, nor compliance with the terms and provisions hereof, conflicts
      or will conflict with or results or will result in a breach or violation
      of any of the terms, conditions or provisions of, or will require any
      consent or approval under, any law, governmental rule or regulation or the
      charter documents, as amended, or bylaws, as amended, of it or any similar
      instrument binding on it or any order, writ, injunction or decree of any
      court or governmental authority against it or by which it or any of its
      properties is bound or any indenture, mortgage or contract or other
      agreement or instrument to which it is a party or by which it or any of
      its properties is bound, or constitutes or will constitute a default
      thereunder or results or will result in the imposition of any lien upon
      any of its properties; and

            (vi) there are no pending or, to its knowledge, threatened actions,
      suits, investigations or proceedings (whether or not purportedly on behalf
      of it) against or affecting it or any of its property before or by any
      court or administrative agency which, if adversely determined, (A) would
      adversely affect the ability of it to perform its obligations under this
      Agreement or (B) would call into question or challenge the validity of
      this Agreement or the enforceability hereof in accordance with the terms
      hereof, nor is the Paying Agent in default with respect to any order of
      any court, governmental authority, arbitration board or administrative
      agency so as to adversely affect its ability to perform its obligations
      under this Agreement.

            SECTION 7. Indemnification. Except for actions expressly required of
the Escrow Agent or the Paying Agent hereunder, each of the Escrow Agent and the
Paying Agent shall 
<PAGE>   19
                                                                              16


in all cases be fully justified in failing or refusing to act hereunder unless
it shall have been indemnified (both in such capacities and individually) by the
party requesting such action in a manner reasonably satisfactory to it against
any and all liability and expense which may be incurred by it by reason of
taking or continuing to take any such action. In the event America West requests
any amendment to any Operative Agreement (as defined in the Note Purchase
Agreement), the Pass Through Trustee agrees to pay all reasonable fees and
expenses (including, without limitation, fees and disbursements of counsel) of
the Escrow Agent and the Paying Agent in connection therewith.

            SECTION 8. Amendment, Etc. Upon request of the Pass Through Trustee
and approval by an Action of Investors, the Escrow Agent shall enter into an
amendment to this Agreement, so long as such amendment does not adversely affect
the rights or obligations of the Escrow Agent or the Paying Agent, provided that
upon request of the Pass Through Trustee and without any consent of the
Investors, the Escrow Agent shall enter into an amendment to this Agreement for
any of the following purposes:

            (1) to correct or supplement any provision in this Agreement which
      may be defective or inconsistent with any other provision herein or to
      cure any ambiguity or correct any mistake or to modify any other provision
      with respect to matters or questions arising under this Agreement,
      provided that any such action shall not materially adversely affect the
      interests of the Investors; or

            (2) to comply with any requirement of the SEC, applicable law, rules
      or regulations of any exchange or quotation system on which the
      Certificates are listed or any regulatory body or the Registration Rights
      Agreement to effectuate the Exchange Offer; or

            (3) to evidence and provide for the acceptance of appointment under
      this Agreement of a successor Escrow Agent, successor Paying Agent or
      successor Pass Through Trustee.

            SECTION 9. Notices. Unless otherwise expressly provided herein, any
notice or other communication under this Agreement shall be in writing
(including by facsimile) and shall be deemed to be given and effective upon
receipt thereof (or, if received outside of business hours, on the next open of
business 
<PAGE>   20
                                                                              17


on a Business Day). All notices shall be sent to (a) in the case of the
Investors, as their respective addresses shall appear in the Register, (b) in
the case of the Escrow Agent, Wilmington Trust Company, 1100 North Market
Street, Wilmington, Delaware 19890, Attention: Corporate Trust Administration
(Telecopier: 302-651-8882), (c) in the case of the Pass Through Trustee,
Wilmington Trust Company, 1100 North Market Street, Wilmington, Delaware 19890,
Attention: Corporate Trust Administration (Telecopier: 302-651-8882), or (d) in
the case of the Paying Agent, Wilmington Trust Company, 1100 North Market
Street, Wilmington, Delaware 19890, Attention: Corporate Trust Administration
(Telecopier: 302-651-8882), in each case with a copy to America West, America
West Airlines, Inc., 4000 East Sky Harbor Boulevard, Phoenix, Arizona 95043,
Attention: Vice President - Treasurer (Telecopier: (602) 693-5886) (or at such
other address as any such party may specify from time to time in a written
notice to the other parties). On or prior to the execution of this Agreement,
the Pass Through Trustee has delivered to the Escrow Agent a certificate
containing specimen signatures of the representatives of the Pass Through
Trustee who are authorized to give notices and instructions with respect to this
Agreement. The Escrow Agent may conclusively rely on such certificate until the
Escrow Agent receives written notice from the Pass Through Trustee to the
contrary.

            SECTION 10. Transfer. No party hereto shall be entitled to assign or
otherwise transfer this Agreement (or any interest herein) other than (in the
case of the Escrow Agent) to a successor escrow agent under Section 1.06 hereof
or (in the case of the Paying Agent) to a successor paying agent under Section
2.04 hereof, and any purported assignment in violation thereof shall be void.
This Agreement shall be binding upon the parties hereto and their respective
successors and (in the case of the Escrow Agent and the Paying Agent) their
respective permitted assigns. Upon the occurrence of the Transfer (as defined
below) contemplated by the Assignment and Assumption Agreement (as defined
below), the Pass Through Trustee shall (without further act) be deemed to have
transferred all of its right, title and interest in and to this Agreement to the
trustee of the Successor Trust (as defined below) and, thereafter, the trustee
of the Successor Trust shall be deemed to be the "Pass Through Trustee"
hereunder with the rights and obligations of the "Pass Through Trustee"
hereunder and each reference herein to "America West Airlines Pass Through Trust
"1998-1C-O" shall be deemed to be a reference to "America West Airlines Pass
Through Trust 1998-1C-S". The parties hereto 
<PAGE>   21
                                                                              18


hereby acknowledge and consent to the Transfer contemplated by the Assignment
and Assumption Agreement. As used herein, "Transfer" means the transfers of the
assets to the Successor Trust contemplated by the Assignment and Assumption
Agreement; "Assignment and Assumption Agreement" means the Assignment and
Assumption Agreement to be entered into between the Pass Through Trustee and the
trustee of the Successor Trust, substantially in the form of Exhibit D to the
Pass Through Trust Agreement; "Successor Trust" means the America West Airlines
Pass Through Trust 1998-1C-S.

            SECTION 11. Entire Agreement. This Agreement sets forth all of the
promises, covenants, agreements, conditions and understandings among the Escrow
Agent, the Paying Agent, the Initial Purchasers and the Pass Through Trustee
with respect to the subject matter hereof, and supersedes all prior and
contemporaneous agreements and undertakings, inducements or conditions, express
or implied, oral or written.

            SECTION 12. Governing Law. This Agreement shall be governed by, and
construed in accordance with, the law of the State of New York.

            SECTION 13. Waiver of Jury Trial Right. EACH OF THE ESCROW AGENT,
THE PAYING AGENT, THE INVESTORS AND THE PASS THROUGH TRUSTEE ACKNOWLEDGES AND
ACCEPTS THAT IN ANY SUIT, ACTION OR PROCEEDING ARISING OUT OF OR RELATING TO
THIS AGREEMENT SUCH PARTY IRREVOCABLY WAIVES ITS RIGHT TO A TRIAL BY JURY.

            SECTION 14. Counterparts. This Agreement may be executed in one or
more counterparts, all of which taken together shall constitute one instrument.
<PAGE>   22
                                                                              19


            IN WITNESS WHEREOF, the Escrow Agent, the Paying Agent, the Initial
Purchasers and the Pass Through Trustee have caused this Escrow and Paying Agent
Agreement (Class C) to be duly executed as of the day and year first above
written.

                                    WILMINGTON TRUST COMPANY, as Escrow Agent

                                    By    /s/ Norma P. Closs
                                       ----------------------------
                                       Name:  Norma P. Closs
                                       Title: Vice President
 
                                    
                                    MORGAN STANLEY & CO. INCORPORATED, 
                                    DONALDSON, LUFKIN & JENRETTE SECURITIES
                                    CORPORATION, MERRILL LYNCH, PIERCE, FENNER &
                                    SMITH INCORPORATED and SALOMON SMITH BARNEY 
                                    INC., as Initial Purchasers


                                    By: MORGAN STANLEY & CO.
                                         INCORPORATED


                                    By    /s/ Tom Cahill
                                       ----------------------------
                                       Name:  Tom Cahill
                                       Title:

                                    WILMINGTON TRUST COMPANY, not in its
                                    individual capacity, but solely as Pass
                                    Through Trustee for and on behalf of America
                                    West Airlines Pass Through Trust
                                    1998-1C-O


                                    By   /s/ James P. Lawler
                                       ----------------------------
                                       Name:  James P. Lawler
                                       Title: Vice President
<PAGE>   23
                                                                              20


                                    WILMINGTON TRUST COMPANY,
                                    as Paying Agent


                                  By   /s/ Norma P. Closs
                                     ----------------------------
                                       Name:  Norma P. Closs
                                       Title: Vice President
<PAGE>   24
                                                                       EXHIBIT A

                  AMERICA WEST AIRLINES 1998-1C ESCROW RECEIPT

                                     No. __

            This Escrow Receipt evidences a fractional undivided interest in
amounts ("Account Amounts") from time to time deposited into a certain paying
agent account (the "Paying Agent Account") described in the Escrow and Paying
Agent Agreement (Class C) dated as of October 6, 1998 (as amended, modified or
supplemented from time to time, the "Escrow and Paying Agent Agreement") among
Wilmington Trust Company, as Escrow Agent (in such capacity, together with its
successors in such capacity, the "Escrow Agent"), Morgan Stanley & Co.
Incorporated, Donaldson, Lufkin & Jenrette Securities Corporation , Merrill
Lynch, Pierce, Fenner & Smith Incorporated and Salomon Smith Barney Inc., as
Initial Purchasers, Wilmington Trust Company, as Pass Through Trustee (in such
capacity, together with its successors in such capacity, the "Pass Through
Trustee") and Wilmington Trust Company, as paying agent (in such capacity,
together with its successors in such capacity, the "Paying Agent"). Capitalized
terms not defined herein shall have the meanings assigned to them in the Escrow
and Paying Agent Agreement.

            This Escrow Receipt is issued under and is subject to the terms,
provisions and conditions of the Escrow and Paying Agent Agreement. By virtue of
its acceptance hereof the holder of this Escrow Receipt assents and agrees to be
bound by the provisions of the Escrow and Paying Agent Agreement and this Escrow
Receipt.

            This Escrow Receipt represents a fractional undivided interest in
amounts deposited from time to time in the Paying Agent Account, and grants or
represents no rights, benefits or interests of any kind in respect of any assets
or property other than such amounts. This Escrow Receipt evidences the same
percentage interest in the Account Amounts as the Fractional Undivided Interest
in the Pass Through Trust evidenced by the Certificate to which this Escrow
Receipt is affixed.

            All payments and distributions made to Receiptholders in respect of
the Escrow Receipt shall be made only from Account Amounts deposited in the
Paying Agent Account. The holder of this Escrow Receipt, by its acceptance of
this Escrow Receipt, agrees that it will look solely to the Account Amounts for
any payment or distribution due to it pursuant to this Escrow 
<PAGE>   25
                                                                               2


Receipt and that it will not have any recourse to America West, the Pass Through
Trustee, the Paying Agent or the Escrow Agent, except as expressly provided
herein or in the Pass Through Trust Agreement. No Receiptholder of this Escrow
Receipt shall have any right to vote or in any manner otherwise control the
operation and management of the Paying Agent Account, nor shall anything set
forth herein, or contained in the terms of this Escrow Receipt, be construed so
as to constitute the Receiptholders from time to time as partners or members of
an association.

            This Escrow Receipt may not be assigned or transferred except in
connection with the assignment or transfer of the Certificate to which this
Escrow Receipt is affixed. After payment to the holder hereof of its Escrow
Interest in the Final Distribution, upon the request of the Pass Through
Trustee, the holder hereof will return this Escrow Receipt to the Pass Through
Trustee.

            The Paying Agent may treat the person in whose name the Certificate
to which this Escrow Receipt is attached as the owner hereof for all purposes,
and the Paying Agent shall not be affected by any notice to the contrary.

            THIS ESCROW RECEIPT SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE
WITH THE LAW OF THE STATE OF NEW YORK.

            IN WITNESS WHEREOF, the Escrow Agent has caused this Escrow Receipt
to be duly executed.

Dated: ______________, 199_

                                    WILMINGTON TRUST COMPANY,
                                    as Escrow Agent

                                    By __________________________
                                       Name:
                                       Title:
<PAGE>   26
                                                                       EXHIBIT B

                             WITHDRAWAL CERTIFICATE
                                    (Class C)

                            WILMINGTON TRUST COMPANY,
                                 as Escrow Agent

Dear Sirs:

            Reference is made to the Escrow and Paying Agent Agreement, dated as
of October 6, 1998 (the "Agreement"). We hereby certify to you that the
conditions to the obligations of the undersigned to execute a Participation
Agreement pursuant to the Note Purchase Agreement have been satisfied. Pursuant
to Section 1.02(c) of the Agreement, please execute the attached Notice of
Withdrawal and immediately transmit by facsimile to the Depositary, at (312)
606-8428, Attention: Vice President - Aerospace.

                                    Very truly yours,

                                    WILMINGTON TRUST COMPANY,
                                    not in its individual capacity but
                                    solely as Pass Through Trustee


                                    By __________________________
                                       Name:
                                       Title:



Dated: ____________, 199_


<PAGE>   1


                                                                       EXECUTION

                                                                    Exhibit 4.21







                             NOTE PURCHASE AGREEMENT

                           Dated as of October 6, 1998

                                      Among

                          AMERICA WEST AIRLINES, INC.,

                            WILMINGTON TRUST COMPANY,
                    as Pass Through Trustee under each of the
                          Pass Through Trust Agreements

                            WILMINGTON TRUST COMPANY,
                             as Subordination Agent

                            WILMINGTON TRUST COMPANY,
                                 as Escrow Agent

                                       and

                            WILMINGTON TRUST COMPANY,
                                 as Paying Agent







<PAGE>   2




                        INDEX TO NOTE PURCHASE AGREEMENT

                                                                            Page

SECTION 1.  Financing of Aircraft..............................................2
SECTION 2.  Conditions Precedent...............................................6
SECTION 3.  Representations and Warranties.....................................6
SECTION 4.  Covenants..........................................................9
SECTION 5.  Notices...........................................................11
SECTION 6.  Expenses..........................................................11
SECTION 7.  Further Assurances................................................12
SECTION 8.  Miscellaneous.....................................................12
SECTION 9.  Governing Law.....................................................13


                                    Schedules

Schedule I                 Aircraft and Scheduled Delivery Months
Schedule II                Pass Through Trust Agreements
Schedule III               Deposit Agreements
Schedule IV                Escrow and Paying Agent Agreements
Schedule V                 Mandatory Document Terms
Schedule VI                Mandatory Economic Terms
Schedule VII               Aggregate Amortization Schedule


                                      Annex

Annex A                    Definitions


                                    Exhibits

Exhibit A-1                Form of Leased Aircraft Participation Agreement
Exhibit A-2                Form of Lease
Exhibit A-3                Form of Leased Aircraft Indenture
Exhibit A-4                Form of Aircraft Purchase Agreement Assignment
Exhibit A-5                Form of Leased Aircraft Trust Agreement
Exhibit B                  Form of Delivery Notice
Exhibit C-1                Form of Owned Aircraft Participation Agreement
Exhibit C-2                Form of Owned Aircraft Indenture

                                       i

<PAGE>   3



                             NOTE PURCHASE AGREEMENT

                  This NOTE PURCHASE AGREEMENT, dated as of October 6, 1998,
among (i) AMERICA WEST AIRLINES, INC., a Delaware corporation (the "Company"),
(ii) WILMINGTON TRUST COMPANY ("WTC"), a Delaware banking corporation, not in
its individual capacity except as otherwise expressly provided herein, but
solely as trustee (in such capacity together with its successors in such
capacity, the "Pass Through Trustee") under each of the three separate Pass
Through Trust Agreements (as defined below), (iii) WILMINGTON TRUST COMPANY, a
Delaware banking corporation, as subordination agent and trustee (in such
capacity together with its successors in such capacity, the "Subordination
Agent") under the Intercreditor Agreement (as defined below), (iv) WILMINGTON
TRUST COMPANY, a Delaware banking corporation, as Escrow Agent (in such capacity
together with its successors in such capacity, the "Escrow Agent"), under each
of the Escrow and Paying Agent Agreements (as defined below) and (v) WILMINGTON
TRUST COMPANY, a Delaware banking corporation, as Paying Agent (in such capacity
together with its successors in such capacity, the "Paying Agent") under each of
the Escrow and Paying Agent Agreements.

                              W I T N E S S E T H:

                  WHEREAS, capitalized terms used but not defined herein shall
have the meanings ascribed to such terms in Annex A hereto;

                  WHEREAS, the Company has obtained commitments from the
Manufacturer pursuant to the Aircraft Purchase Agreement for the delivery of the
eight aircraft listed on Schedule I hereto (together with any aircraft
substituted therefor in accordance with the Aircraft Purchase Agreement prior to
the delivery thereof, the "Aircraft");

                  WHEREAS, pursuant to each of the Pass Through Trust Agreements
set forth in Schedule II hereto, and concurrently with the execution and
delivery of this Agreement, separate grantor trusts (collectively, the "Pass
Through Trusts" and, individually, a "Pass Through Trust") have been created to
facilitate certain of the transactions contemplated hereby, including, without
limitation, the issuance and sale of pass through certificates pursuant thereto
(collectively, the "Certificates") to provide for a portion of the financing of
the Aircraft;

                  WHEREAS, the Company has entered into the Purchase Agreement
dated as of September 24, 1998 (the "Purchase Agreement") with the several
initial purchasers (the "Initial Purchasers") named therein, which provides that
the Company will cause each Pass Through Trustee to issue and sell the
Certificates to the Initial Purchasers;

                  WHEREAS, concurrently with the execution and delivery of this
Agreement, (i) the Escrow Agents and the Depositary entered into the Deposit
Agreements set forth in Schedule III hereto (the "Deposit Agreements") whereby
the applicable Escrow Agent agreed to direct the Initial Purchasers to make
certain deposits referred to therein on the Issuance Date (the "Initial
Deposits") and to permit the applicable Pass Through Trustee to make additional
deposits from time to time thereafter (the Initial Deposits together with such
additional deposits are collectively referred to as the "Deposits") and (ii) the
Pass Through Trustees, the Initial Purchasers, the Paying Agents and the Escrow
Agents entered into the Escrow and Paying Agent Agreements set 


<PAGE>   4
                                                                               2


forth in Schedule IV hereto (the "Escrow and Paying Agent Agreements") whereby,
among other things, (a) the Initial Purchasers agreed to deliver an amount equal
to the amount of the Initial Deposits to the Depositary on behalf of the
applicable Escrow Agent and (b) the applicable Escrow Agent, upon the Depositary
receiving such amount, has agreed to deliver escrow receipts to be affixed to
each Certificate;

                  WHEREAS, prior to (or, in the case of the utilization of
bridge financing, after) the delivery of each Aircraft from the Manufacturer,
the Company will determine whether to enter into a leveraged lease transaction
as lessee with respect to such Aircraft (a "Leased Aircraft") or to purchase as
owner such Aircraft (an "Owned Aircraft") and will give to the Pass Through
Trustee a Delivery Notice (as defined below) specifying its election;

                  WHEREAS, upon receipt of a Delivery Notice with respect to an
Aircraft, subject to the terms and conditions of this Agreement, the applicable
Pass Through Trustees will enter into the applicable Financing Agreements
relating to such Aircraft;

                  WHEREAS, upon the delivery of each Aircraft, each Pass Through
Trustee will fund its purchase of Equipment Notes with the proceeds of one or
more Deposits withdrawn by the applicable Escrow Agent under the related Deposit
Agreement bearing the same interest rate as the Certificates issued by such Pass
Through Trust; and

                  WHEREAS, concurrently with the execution and delivery of this
Agreement, (i) ABN AMRO Bank N.V., a bank organized under the laws of the
Netherlands, acting through its Chicago branch (the "Liquidity Provider"), has
entered into three revolving credit agreements (each, a "Liquidity Facility"),
one each for the benefit of the Certificateholders of each Pass Through Trust,
with the Subordination Agent, as agent for the Pass Through Trustee on behalf of
each such Pass Through Trust and (ii) the Pass Through Trustee, the Liquidity
Provider and the Subordination Agent have entered into the Intercreditor
Agreement, dated as of the date hereof (the "Intercreditor Agreement");

                  NOW, THEREFORE, in consideration of the foregoing premises and
the mutual agreements herein contained and other good and valuable
consideration, the receipt and adequacy of which are hereby acknowledged, the
parties hereto agree as follows:

                  SECTION 1. Financing of Aircraft. (a) The Company confirms
that it has entered into the Aircraft Purchase Agreement with the Manufacturer
pursuant to which the Company has agreed to purchase, and the Manufacturer has
agreed to deliver, the Aircraft in the months specified in Schedule I hereto,
all on and subject to terms and conditions specified in the Aircraft Purchase
Agreement. The Company agrees to finance the Aircraft in the manner provided
herein, all on and subject to the terms and conditions hereof and of the
relevant Financing Agreements.

                  (b) In furtherance of the foregoing, the Company agrees to
give the parties hereto, the Depositary and each of the Rating Agencies not less
than two Business Days' prior notice (a "Delivery Notice") of the scheduled
delivery date (the "Scheduled Delivery Date") (or, in the case of a substitute
Delivery Notice under Section 1(e) or (f) hereof, one Business Day's prior
notice) in respect of each Aircraft under the Aircraft Purchase Agreement, or in
the case of 


<PAGE>   5

                                                                               3

the utilization of bridge financing as contemplated by Section 1(e) hereof in
respect of any Aircraft, one Business Day's prior notice of the date of the
financing of such Aircraft pursuant to the relevant Financing Agreements, which
notice shall:

                  (i) specify whether the Company has elected to treat such
         Aircraft as a Leased Aircraft or an Owned Aircraft;

                  (ii) specify the Scheduled Delivery Date of such Aircraft
         (which shall be a Business Day before the Cut-off Date and, except as
         provided in Section 1(f) hereof, the date (the "Funding Date") on which
         the financing therefor in the manner provided herein shall be
         consummated);

                  (iii) instruct the Pass Through Trustee to execute and deliver
         to the relevant Escrow Agent a withdrawal certificate in the form of
         Exhibit B to the Escrow Agent so as to provide a Notice of Purchase
         Withdrawal to the Depositary with respect to the Equipment Notes to be
         issued in connection with the financing of such Aircraft;

                  (iv) instruct the Pass Through Trustee to enter into the
         Participation Agreement included in the Financing Agreements with
         respect to such Aircraft in such form and at such a time on or before
         the Funding Date specified in such Delivery Notice and to perform its
         obligations thereunder;

                  (v) specify the aggregate principal amount of each series of
         Equipment Notes to be issued, and purchased by the Pass Through
         Trustees, in connection with the financing of such Aircraft scheduled
         to be delivered on such Funding Date (which shall in all respects
         comply with the Mandatory Economic Terms); and

                  (vi) if such Aircraft is to be a Leased Aircraft, certify that
         the related Owner Participant (A) is not an Affiliate of the Company
         and (B) based on the representations of such Owner Participant, is
         either (1) a Qualified Owner Participant or (2) any other person the
         obligations of which under the Owner Participant Agreements (as defined
         in the applicable Participation Agreement) are guaranteed by a
         Qualified Owner Participant.

Notwithstanding the foregoing, in the event the date of issuance of the
Certificates coincides with the Scheduled Delivery Date of the first Aircraft to
be financed pursuant to the terms hereof, the Delivery Notice therefor may be
delivered to the parties hereto on such Scheduled Delivery Date.

                  (c) Upon receipt of a Delivery Notice, the Pass Through
Trustees shall, and shall cause the Subordination Agent to, enter into and
perform their obligations under the Participation Agreement and other
instructions specified in such Delivery Notice, provided that such Participation
Agreement and the other Lease Financing Agreements or Owner Financing Agreements
to be entered into pursuant to such Participation Agreement shall be in the
forms thereof annexed hereto in all material respects with such changes therein
as shall have been requested by the related Owner Participant (in the case of
Lease Financing Agreements) or by the initial purchasers of the Series D
Equipment Notes or Class D Pass Through Certificates, agreed to by the Company
and, if modified in any material respect, as to which Rating Agency Confirmation
shall have been obtained from each Rating Agency by the Company (to be delivered
by the 


<PAGE>   6
                                                                               4

Company to the applicable Pass Through Trustee on or before the relevant
Delivery Date, it being understood that if Rating Agency Confirmation shall have
been received with respect to any Financing Agreements and such Financing
Agreements are utilized for subsequent Aircraft (or Substitute Aircraft) without
material modifications, no additional Rating Agency Confirmation shall be
required); provided, however, that the relevant Financing Agreements as executed
and delivered shall not vary the Mandatory Economic Terms and shall contain the
Mandatory Document Terms. With respect to each Aircraft, WTC (or such other
person that meets the eligibility requirements to act as mortgagee under the
Leased Aircraft Indenture or Owned Aircraft Indenture) shall execute as Loan
Trustee the Financing Agreements relating to such Aircraft to which such Loan
Trustee is intended to be a party, and the Company shall concurrently therewith
execute such Financing Agreements to which the Company is intended to be a party
and perform its respective obligations thereunder. Upon the request of either
Rating Agency, the Company shall deliver or cause to be delivered to such Rating
Agency a true and complete copy of each Financing Agreement relating to the
financing of each Aircraft together with a true and complete set of the closing
documentation (including legal opinions) delivered to the related Loan Trustee,
Subordination Agent and Pass Through Trustee under the related Participation
Agreement.

                  (d) If after giving any Delivery Notice, there shall be a
delay in the delivery of an Aircraft, or if on the Scheduled Delivery Date of an
Aircraft the financing thereof in the manner contemplated hereby shall not be
consummated for whatever reason, the Company shall give the parties hereto
prompt notice thereof. Concurrently with the giving of such notice of
postponement or subsequently, the Company shall give the parties hereto a
substitute Delivery Notice specifying the date to which such delivery and
related financing shall have been re-scheduled (which shall be a Business Day
before the Cut-off Date on which the Escrow Agents shall be entitled to withdraw
one or more Deposits under each of the applicable Deposit Agreements to enable
each applicable Pass Through Trustee to fund its purchase of the related
Equipment Notes). Upon receipt of any such notice of postponement, each
applicable Pass Through Trustee shall comply with its obligations under Section
7.01 of each of the Pass Through Trust Agreements and thereafter the financing
of the relevant Aircraft shall take place on the re-scheduled Delivery Date
therefor (all on and subject to the terms and conditions of the relevant
Financing Agreements) unless further postponed as provided herein.

                  (e) Anything in this Section 1 to the contrary
notwithstanding, the Company shall have the right at any time on or before the
Scheduled Delivery Date of any Aircraft, and subsequent to its giving a Delivery
Notice therefor, to postpone the Scheduled Delivery Date of such Aircraft so as
to enable the Company to change its election to treat such Aircraft as a Leased
Aircraft or an Owned Aircraft by written notice of such postponement to the
other parties hereto. The Company shall subsequently give the parties hereto a
substitute Delivery Notice complying with the provisions of Section 1(b) hereof
and specifying the new Funding Date for such postponed Aircraft (which shall be
a Business Day occurring before the Cut-off Date and on which the Escrow Agents
shall be entitled to withdraw Deposits under each of the applicable Deposit
Agreements sufficient to enable each applicable Pass Through Trustee to fund its
purchase of the related Equipment Notes). In addition, the Company shall have
the further right, anything in this Section 1 to the contrary notwithstanding,
to accept delivery of an Aircraft under the Aircraft Purchase Agreement on the
Delivery Date thereof by utilization of bridge financing of such Aircraft and
promptly thereafter give the parties hereto a Delivery Notice specifying a



<PAGE>   7

                                                                               5

Funding Date not later than 90 days after the Delivery Date of such Aircraft and
no later than the Cut-off Date and otherwise complying with the provisions of
Section 1(b) hereof. All other terms and conditions of this Note Purchase
Agreement shall apply to the financing of any such Aircraft on the re-scheduled
Funding Date therefor except (i) the re-scheduled Funding Date shall be deemed
the Delivery Date of such Aircraft for all purposes of this Section 1, (ii) the
related Financing Agreements shall be amended to reflect the original delivery
of such Aircraft to the Company and (iii) the related Financing Agreements shall
be amended to reflect the seller of such Aircraft, and the recipient of payment
of the purchase price therefor, as the Company and (iv) in the case of a Leased
Aircraft, the Aircraft Purchase Agreement Assignment shall be modified to cover
only an assignment of the relevant warranties.

                  (f) If the Scheduled Delivery Date for any Aircraft is delayed
for any reason (including the casualty loss thereof) more than 30 days beyond
the last day of the month set forth opposite such Aircraft under the heading
"Scheduled Delivery Months" in Schedule I hereto, the Company may identify for
delivery a substitute aircraft therefor meeting the following conditions (a
"Substitute Aircraft"): (i) a Substitute Aircraft must be an Airbus A319-100 or
A320-200 aircraft manufactured after the date of this Agreement, (ii) one or
more Substitute Aircraft of the same or different types may be substituted for
one or more Aircraft of the same or different types so long as after giving
effect thereto such substitution does not vary the Mandatory Economic Terms and
(iii) the Company shall be obligated to obtain Rating Agency Confirmation in
respect of the replacement of any Aircraft by Substitute Aircraft. Upon the
satisfaction of the conditions set forth above with respect to a Substitute
Aircraft, the Aircraft to be replaced shall cease to be subject to this
Agreement and all rights and obligations of the parties hereto concerning such
Aircraft shall cease, and such Substitute Aircraft shall become and thereafter
be subject to the terms and conditions of this Agreement to the same extent as
such Aircraft.

                  (g) The Company shall have no liability for the failure of the
Pass Through Trustees to purchase Equipment Notes with respect to any Aircraft
or Substitute Aircraft, other than the Company's obligation, if any, to pay the
Deposit Make-Whole Premium pursuant to Section 4(a)(i) of this Agreement.

                  (h) The parties agree that if, in connection with the delivery
of an Aircraft or Substitute Aircraft, any Owner Participant who is to be a
party to any Lease Financing Agreement shall not be a "Citizen of the United
States" within the meaning of Section 40102(a)(15) of the Act, then the
applicable Lease Financing Agreements shall be modified, consistent with the
Mandatory Document Terms, (x) to require such Owner Participant to enter into a
voting trust, voting powers or similar arrangement satisfactory to the Company
that (A) enables such Aircraft or Substitute Aircraft to be registered in the
United States and (B) complies with the FAA regulations issued under the Act
applicable thereto and (y) to be otherwise consistent with such state of
affairs.

                  (i) Anything herein to the contrary notwithstanding, the
Company shall not have the right, and shall not be entitled, at any time to
request the issuance of Equipment Notes of any series to any Pass Through
Trustee in an aggregate principal amount in excess of the amount of the Deposits
then available for withdrawal by the Escrow Agent under and in accordance with
the provisions of the related Deposit Agreement.


<PAGE>   8

                                                                               6

                  SECTION 2. Conditions Precedent. The obligation of the Pass
Through Trustees to enter into, and to cause the Subordination Agent to enter
into, any Participation Agreement as directed pursuant to a Delivery Notice and
to perform its obligations under such Participation Agreement is subject to
satisfaction of the following conditions:

                  (a) no Triggering Event shall have occurred; and

                  (b) the Company shall have delivered a certificate to each
         such Pass Through Trustee and each Liquidity Provider stating that (i)
         such Participation Agreement and the other Financing Agreements to be
         entered into pursuant to such Participation Agreement do not vary the
         Mandatory Economic Terms and contain the Mandatory Document Terms and
         (ii) any substantive modification of such Financing Agreements from the
         forms thereof attached to this Agreement, subject to the modifications
         permitted by Sections 1(e) and 1(h) hereof, do not materially and
         adversely affect the Certificateholders, and such certification shall
         be true and correct.

                  Anything herein to the contrary notwithstanding, the
obligation of each Pass Through Trustee to purchase Equipment Notes shall
terminate on the Cut-off Date.

                  SECTION 3. Representations and Warranties. (a) The Company
represents and warrants that:

                           (i) the Company is duly incorporated, validly
                  existing and in good standing under the laws of the State of
                  Delaware and is a "citizen of the United States" as defined in
                  49 U.S.C. Section 40102, and has the full corporate power,
                  authority and legal right under the laws of the State of
                  Delaware to execute and deliver this Agreement and each
                  Financing Agreement to which it will be a party and to carry
                  out the obligations of the Company under this Agreement and
                  each Financing Agreement to which it will be a party;

                           (ii) the execution and delivery by the Company of
                  this Agreement and the performance by the Company of its
                  obligations under this Agreement have been duly authorized by
                  the Company and will not violate its Certificate of
                  Incorporation or by-laws or (other than any violation that
                  would not result in a Material Adverse Change to the Company)
                  the provisions of any indenture, mortgage, contract or other
                  agreement to which it is a party or by which it is bound; and

                           (iii) assuming the due authorization, execution and
                  delivery hereof by the other parties hereto this Agreement
                  constitutes the legal, valid and binding obligation of the
                  Company, enforceable against it in accordance with its terms,
                  except as the same may be limited by applicable bankruptcy,
                  insolvency, reorganization, moratorium or similar laws
                  affecting the rights of creditors generally and by general
                  principles of equity, whether considered in a proceeding at
                  law or in equity.

                  (b)      WTC represents and warrants that:


<PAGE>   9

                                                                               7

                           (i) WTC is duly incorporated, validly existing and in
                  good standing under the laws of the State of Delaware and is a
                  "citizen of the United States" as defined in 49 U.S.C. Section
                  40102, and has the full corporate power, authority and legal
                  right under the laws of the State of Delaware and the United
                  States pertaining to its banking, trust and fiduciary powers
                  to execute and deliver this Agreement and each Financing
                  Agreement to which it will be a party and to carry out the
                  obligations of WTC, in its capacity as Subordination Agent,
                  Pass Through Trustee or Paying Agent, as the case may be,
                  under this Agreement and each Financing Agreement to which it
                  will be a party;

                           (ii) the execution and delivery by WTC, in its
                  capacity as Subordination Agent, Pass Through Trustee or
                  Paying Agent, as the case may be, of this Agreement and the
                  performance by WTC, in its capacity as Subordination Agent,
                  Pass Through Trustee or Paying Agent, as the case may be, of
                  its obligations under this Agreement have been duly authorized
                  by WTC, in its capacity as Subordination Agent, Pass Through
                  Trustee or Paying Agent, as the case may be, and will not
                  violate its articles of association or by-laws or the
                  provisions of any indenture, mortgage, contract or other
                  agreement to which it is a party or by which it is bound; and

                           (iii) this Agreement constitutes the legal, valid and
                  binding obligations of WTC, in its capacity as Subordination
                  Agent, Pass Through Trustee or Paying Agent, as the case may
                  be, enforceable against it in accordance with its terms,
                  except as the same may be limited by applicable bankruptcy,
                  insolvency, reorganization, moratorium or similar laws
                  affecting the rights of creditors generally and by general
                  principles of equity, whether considered in a proceeding at
                  law or in equity.

                  (c) The Pass Through Trustee hereby confirms to each of the
other parties hereto that its representations and warranties set forth in
Section 7.15 of each Pass Through Trust Agreement are true and correct as of the
date hereof.

                  (d) The Subordination Agent represents and warrants that:

                           (i) the Subordination Agent is duly incorporated,
                  validly existing and in good standing under the laws of the
                  State of Delaware, and has the full corporate power, authority
                  and legal right under the laws of the State of Delaware and
                  the United States pertaining to its banking, trust and
                  fiduciary powers to execute and deliver this Agreement and
                  each Financing Agreement to which it is or will be a party and
                  to perform its obligations under this Agreement and each
                  Financing Agreement to which it is or will be a party;

                           (ii) this Agreement has been duly authorized,
                  executed and delivered by the Subordination Agent; this
                  Agreement constitutes the legal, valid and binding obligations
                  of the Subordination Agent enforceable against it in
                  accordance with its terms, except as the same may be limited
                  by applicable bankruptcy, insolvency, reorganization,
                  moratorium or similar laws affecting the 


<PAGE>   10
                                                                               8


                  rights of creditors generally and by general principles of
                  equity, whether considered in a proceeding at law or in
                  equity;

                           (iii) none of the execution, delivery and performance
                  by the Subordination Agent of this Agreement contravenes any
                  law, rule or regulation of the State of Delaware or any United
                  States governmental authority or agency regulating the
                  Subordination Agent's banking, trust or fiduciary powers or
                  any judgment or order applicable to or binding on the
                  Subordination Agent and do not contravene the Subordination
                  Agent's articles of association or by-laws or result in any
                  breach of, or constitute a default under, any agreement or
                  instrument to which the Subordination Agent is a party or by
                  which it or any of its properties may be bound;

                           (iv) neither the execution and delivery by the
                  Subordination Agent of this Agreement nor the consummation by
                  the Subordination Agent of any of the transactions
                  contemplated hereby requires the consent or approval of, the
                  giving of notice to, the registration with, or the taking of
                  any other action with respect to, any Delaware governmental
                  authority or agency or any federal governmental authority or
                  agency regulating the Subordination Agent's banking, trust or
                  fiduciary powers;

                           (v) there are no Taxes payable by the Subordination
                  Agent imposed by the State of Delaware or any political
                  subdivision or taxing authority thereof in connection with the
                  execution, delivery and performance by the Subordination Agent
                  of this Agreement (other than franchise or other taxes based
                  on or measured by any fees or compensation received by the
                  Subordination Agent for services rendered in connection with
                  the transactions contemplated by the Intercreditor Agreement
                  or any of the Liquidity Facilities), and there are no Taxes
                  payable by the Subordination Agent imposed by the State of
                  Delaware or any political subdivision thereof in connection
                  with the acquisition, possession or ownership by the
                  Subordination Agent of any of the Equipment Notes (other than
                  franchise or other taxes based on or measured by any fees or
                  compensation received by the Subordination Agent for services
                  rendered in connection with the transactions contemplated by
                  the Intercreditor Agreement or any of the Liquidity
                  Facilities); and

                           (vi) there are no pending or threatened actions or
                  proceedings against the Subordination Agent before any court
                  or administrative agency which individually or in the
                  aggregate, if determined adversely to it, would materially
                  adversely affect the ability of the Subordination Agent to
                  perform its obligations under this Agreement.

                  (e) The Escrow Agent represents and warrants that:

                           (i) the Escrow Agent is duly incorporated, validly
                  existing and in good standing under the laws of the State of
                  Delaware and has the full corporate power, authority and legal
                  right under the laws of the State of Delaware pertaining 


<PAGE>   11
                                                                               9


                  to its banking, trust and fiduciary powers to execute and
                  deliver this Agreement, each Deposit Agreement and each Escrow
                  and Paying Agent Agreement (collectively, the "Escrow Agent
                  Agreements") and to carry out the obligations of the Escrow
                  Agent under each of the Escrow Agent Agreements;

                           (ii) the execution and delivery by the Escrow Agent
                  of each of the Escrow Agent Agreements and the performance by
                  the Escrow Agent of its obligations hereunder and thereunder
                  have been duly authorized by the Escrow Agent and will not
                  violate its articles of association or by-laws or the
                  provisions of any indenture, mortgage, contract or other
                  agreement to which it is a party or by which it is bound; and

                           (iii) each of the Escrow Agent Agreements constitutes
                  the legal, valid and binding obligations of the Escrow Agent
                  enforceable against it in accordance with its terms, except as
                  the same may be limited by applicable bankruptcy, insolvency,
                  reorganization, moratorium or similar laws affecting the
                  rights of creditors generally and by general principles of
                  equity, whether considered in a proceeding at law or in
                  equity.

                  (f) The Paying Agent represents and warrants that:

                           (i) the Paying Agent is duly incorporated, validly
                  existing and in good standing under the laws of the State of
                  Delaware and has the full corporate power, authority and legal
                  right under the laws of the State of Delaware and the United
                  States pertaining to its banking, trust and fiduciary powers
                  to execute and deliver this Agreement and the Escrow and
                  Paying Agent Agreement (collectively, the "Paying Agent
                  Agreements") and to carry out the obligations of the Paying
                  Agent under each of the Paying Agent Agreements;

                           (ii) the execution and delivery by the Paying Agent
                  of each of the Paying Agent Agreements and the performance by
                  the Paying Agent of its obligations hereunder and thereunder
                  have been duly authorized by the Paying Agent and will not
                  violate its articles of association or by-laws or the
                  provisions of any indenture, mortgage, contract or other
                  agreement to which it is a party or by which it is bound; and

                           (iii) each of the Paying Agent Agreements constitutes
                  the legal, valid and binding obligations of the Paying Agent
                  enforceable against it in accordance with its terms, except as
                  the same may be limited by applicable bankruptcy, insolvency,
                  reorganization, moratorium or similar laws affecting the
                  rights of creditors generally and by general principles of
                  equity, whether considered in a proceeding at law or in
                  equity.

                  SECTION 4. Covenants. (a) The Company covenants with each of
         the other parties hereto that:

                  (i) on the date that the Depositary is obligated to pay the
         amount of the Final Withdrawal to the Paying Agent pursuant to a
         Deposit Agreement relating to any Trust, 


<PAGE>   12
                                                                              10


         the Company shall pay to the Pass Through Trustee of such Trust no
         later than 12:30 p.m. (New York time) an amount equal to the Deposit
         Make-Whole Premium, if any, required to be paid in respect of such
         Final Withdrawal amount;

                  (ii) subject to Section 4(a)(iv) of this Agreement, the
         Company shall at all times maintain its corporate existence;

                  (iii) the Company shall at all times remain a U.S. Air Carrier
         (as defined in the Financing Agreements);

                  (iv) Section 13.2.1 of each Lease is hereby incorporated by
         reference herein;

                  (v) the Company agrees to provide written notice to each of
         the parties hereto of the occurrence of the Cut-off Date no later than
         one Business Day after the date thereof; such notice to refer
         specifically to the Pass Through Trustee's obligation to assign,
         transfer and deliver all of its right, title and interest to the Trust
         Property (as defined in each Pass Through Trust Agreement) to the
         trustee of the Related Trust (as defined in each Pass Through Trust
         Agreement) in accordance with Section 11.01 of each of the Pass Through
         Trust Agreements; and

                  (vi) the Company shall not issue Series D Equipment Notes
         pursuant to any Owned Aircraft Indenture or Leased Aircraft Indenture
         unless it shall have obtained written confirmation from each Rating
         Agency that the issuance of such Series D Equipment Notes will not
         result in (i) a reduction of the rating for any Class of Certificates
         below the then current rating for such Class of Certificates or (ii) a
         withdrawal or suspension of the rating of any Class of Certificates; if
         such conditions to the issuance of Series D Equipment Notes are
         satisfied, the parties hereto agree to enter into such amendments and
         modifications to the Intercreditor Agreement, each Pass Through Trust
         Agreement and the other Financing Agreements as shall be requested by
         the Company to facilitate the issuance of the same and any Series D
         Pass Through Certificates.

                  (b) WTC, in its individual capacity, covenants with each of
the other parties to this Agreement that it will, immediately upon obtaining
knowledge of any facts that would cast doubt upon its continuing status as a
"citizen of the United States" as defined in 49 U.S.C. Section 40102 and
promptly upon public disclosure of negotiations in respect of any transaction
which would or might adversely affect such status, notify in writing all parties
hereto of all relevant matters in connection therewith. Upon WTC giving any such
notice, WTC shall, subject to Section 8.02 of any Indenture then entered into,
resign as Loan Trustee in respect of such Indenture.

                  (c) the Subordination Agent covenants with each of the other
parties hereto that it will not agree or consent to any amendment or
modification to any Liquidity Facility or the Intercreditor Agreement without
the Company's consent, if such amendment or modification would adversely affect
the interests of the Company.

                  (d) The Escrow Agent covenants with each of the other parties
hereto that it will not agree or consent to any amendment or modification to any
Deposit Agreement or 


<PAGE>   13
                                                                              11


Escrow and Paying Agent Agreement without the Company's consent, if such
amendment or modification would adversely affect the interests of the Company.

                  SECTION 5. Notices. Unless otherwise expressly permitted by
the terms hereof, all notices, requests, demands, authorizations, directions,
consents, waivers and other communications required or permitted to be made,
given, furnished or filed hereunder shall be in writing (it being understood
that the specification of a writing in certain instances and not in others does
not imply an intention that a writing is not required as to the latter), shall
refer specifically to this Agreement, and shall be personally delivered, sent by
facsimile or telecommunication transmission (which in either case provides
written confirmation to the sender of its delivery), sent by registered mail or
certified mail, return receipt requested, postage prepaid, or sent by overnight
courier service, in each case to the respective address or facsimile number set
forth for such party below the signature of such party at the foot of this
Agreement, or to such other address, facsimile or other number as each party
hereto may hereafter specify by notice to the other parties hereto. Each such
notice, request, demand, authorization, direction, consent, waiver or other
communication shall be effective when received or, if made, given, furnished or
filed by facsimile or telecommunication transmission, when received unless
received outside of business hours, in which case on the next open of business
on a Business day.

                  SECTION 6. Expenses. (a) The Company agrees to pay to the
Subordination Agent when due an amount or amounts equal to the fees payable to
the Liquidity Provider under Section 2.03 of each Liquidity Facility and the
related Fee Letter (as defined in the Intercreditor Agreement) multiplied by a
fraction the numerator of which shall be the then outstanding aggregate amount
of the Deposits under the Deposit Agreements and the denominator of which shall
be the sum of (x) the then outstanding aggregate principal amount of the Series
A Equipment Notes, Series B Equipment Notes and Series C Equipment Notes issued
under all of the Indentures and (y) the then outstanding aggregate amount of the
Deposits under the Deposit Agreements.

                  (b) So long as no Equipment Notes have been issued in respect
of any Aircraft, the Company agrees to pay (i) to the Subordination Agent when
due (A) the amount equal to interest on any Downgrade Advance (other than any
Applied Downgrade Advance) payable under Section 3.07 of each Liquidity Facility
minus Investment Earnings while such Downgrade Advance shall be outstanding, (B)
the amount equal to interest on any Non-Extension Advance (other than any
Applied Non-Extension Advance) payable under Section 3.07 of each Liquidity
Facility minus Investment Earnings while such Non-Extension Advance shall be
outstanding and (C) any other amounts owed to the Liquidity Provider by the
Subordination Agent as borrower under each Liquidity Facility (other than
amounts due as repayment of advances thereunder or as interest on such advances,
except to the extent payable pursuant to clause (A) or (B)), (ii) all
compensation and reimbursement of expenses, disbursements and advances payable
by the Company under the Pass Through Trust Agreements, (iii) all compensation
and reimbursement of expenses and disbursements payable to the Subordination
Agent under the Intercreditor Agreement (as may be modified by any separate
letter agreement) except with respect to any Unindemnified Taxes incurred by the
Subordination Agent in connection with the transactions contemplated by the
Intercreditor Agreement and (iv) in the event the Company requests any amendment
to any Operative Agreement, all reasonable fees and expenses (including, without
limitation, fees and disbursements of counsel) of the 


<PAGE>   14
                                                                              12


Escrow Agent and/or the Paying Agent in connection therewith. For purposes of
this Section 6(b), the terms "Applied Downgrade Advance", "Applied Non-Extension
Advance", "Downgrade Advance", "Investment Earnings" and "Non-Extension Advance"
shall have the meanings specified in each Liquidity Facility.

                  SECTION 7. Further Assurances. Each party hereto shall duly
execute, acknowledge and deliver, or shall cause to be executed, acknowledged
and delivered, all such further agreements, instruments, certificates or
documents, and shall do and cause to be done such further acts and things, in
any case, as any other party hereto shall reasonably request in connection with
its administration of, or to carry out more effectually the purposes of, or to
assure better and confirm unto it the rights and benefits to be provided under,
this Agreement.

                  SECTION 8. Miscellaneous. (a) Provided that the transactions
contemplated hereby have been consummated, and except as otherwise provided for
herein, the representations, warranties and agreements herein of the Company,
the Subordination Agent, the Escrow Agent and the Pass Through Trustee, and the
Company's, the Subordination Agent's, the Escrow Agent's and the Pass Through
Trustee's obligations under any and all thereof, shall survive the financing of
each Aircraft hereunder but shall terminate on the expiration or other
termination of this Agreement.

                  (b) This Agreement may be executed in any number of
counterparts (and each of the parties hereto shall not be required to execute
the same counterpart). Each counterpart of this Agreement, including a signature
page executed by each of the parties hereto, shall be an original counterpart of
this Agreement, but all of such counterparts together shall constitute one
instrument. Neither this Agreement nor any of the terms hereof may be
terminated, amended, supplemented, waived or modified orally, but only by an
instrument in writing signed by the party against which the enforcement of the
termination, amendment, supplement, waiver or modification is sought. The index
preceding this Agreement and the headings of the various Sections of this
Agreement are for convenience of reference only and shall not modify, define,
expand or limit any of the terms or provisions hereof. The terms of this
Agreement shall be binding upon, and shall inure to the benefit of, the Company
and its successors and permitted assigns, the Pass Through Trustee and its
successors as Pass Through Trustee (and any additional trustee appointed) under
any of the Pass Through Trust Agreements, the Escrow Agent and its successors as
Escrow Agent under the Escrow and Paying Agent Agreements, the Paying Agent and
its successors as Paying Agent under the Escrow and Paying Agent Agreement and
the Subordination Agent and its successors as Subordination Agent under the
Intercreditor Agreement.

                  (c) This Agreement is not intended to, and shall not, provide
any person not a party hereto (other than the Initial Purchasers and each of the
beneficiaries of Section 6 hereof) with any rights of any nature whatsoever
against any of the parties hereto, and no person not a party hereto (other than
the Initial Purchasers and each of the beneficiaries of Section 6 hereof) shall
have any right, power or privilege in respect of, or have any benefit or
interest arising out of, this Agreement.


<PAGE>   15
                                                                              13


                  SECTION 9. Governing Law. THIS AGREEMENT SHALL BE GOVERNED BY,
AND CONSTRUED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK. THIS
AGREEMENT IS BEING DELIVERED IN THE STATE OF NEW YORK.



<PAGE>   16
                                                                              14



                  IN WITNESS WHEREOF, the parties hereto have caused this
Agreement to be duly executed by their respective officers thereunto duly
authorized as of the day and year first above written.

                                        AMERICA WEST AIRLINES, INC.


                                        By /s/ W. Douglas Parker
                                          --------------------------------------
                                           Name: W. Douglas Parker
                                           Title: Sr. Vice President & CFO

                                        Address:  4000 East Sky Harbor Boulevard
                                                  Phoenix, Arizona 85034
                                                  Attention: Vice President
                                                    - Treasurer
                                                  Facsimile:  (602) 693-5886


                                        WILMINGTON TRUST COMPANY,
                                        not in its individual capacity, except 
                                        as otherwise provided herein, but solely
                                        as Pass Through Trustee


                                        By /s/ Jill K. Morrison
                                          --------------------------------------
                                           Name: Jill K. Morrison
                                           Title: Administrative Account Manager

                                        Address:  Rodney Square North
                                                  1100 North Market Street
                                                  Wilmington, Delaware 19890
                                                  Attention:  Corporate Trust
                                                    Administration
                                                  Facsimile:  (302) 651-8882




<PAGE>   17
                                                                              15



                                        WILMINGTON TRUST COMPANY,
                                        not in its individual capacity, except
                                        as otherwise provided herein, but 
                                        solely as Subordination Agent


                                        By /s/ Donald G. Mackelcan
                                          --------------------------------------
                                              Name: Donald G. Mackelcan
                                              Title: Assistant Vice President

                                        Address: Rodney Square North
                                                 1100 North Market Street
                                                 Wilmington, Delaware 19890
                                                 Attention:  Corporate Trust
                                                              Administration
                                                 Facsimile:  (302) 651-8882


                                        WILMINGTON TRUST COMPANY,
                                        as Escrow Agent


                                        By /s/ Donald G. Mackelcan
                                          --------------------------------------
                                              Name: Donald G. Mackelcan
                                              Title: Assistant Vice President

                                        Address: Rodney Square North
                                                 1100 North Market Street
                                                 Wilmington, Delaware 19890
                                                 Attention:  Corporate Trust
                                                              Administration
                                                 Facsimile:  (302) 651-8882


                                        WILMINGTON TRUST COMPANY,
                                        as Paying Agent

                                        By /s/ Donald G. Mackelcan
                                          --------------------------------------
                                              Name: Donald G. Mackelcan
                                              Title: Assistant Vice President

                                        Address: Rodney Square North
                                                 1100 North Market Street
                                                 Wilmington, Delaware 19890
                                                 Attention:  Corporate Trust
                                                              Administration
                                                 Facsimile:  (302) 651-8882




<PAGE>   18


                                  SCHEDULE I to
                             Note Purchase Agreement

                     AIRCRAFT AND SCHEDULED DELIVERY MONTHS

<TABLE>
<CAPTION>
                                         Expected                     Expected                  
                                       Registration                 Manufacturer's                Scheduled    
 Aircraft Type                            Number                   Serial Number                Delivery Month 
 -------------                            ------                   -------------                -------------- 
<S>                                    <C>                         <C>                          <C> 
Airbus A319-132                           N801AW                         889                     October 1998
Airbus A319-132                           N802AW                         924                     December 1998
Airbus A319-132                           N803AW                         931                     December 1998
Airbus A319-132                           N804AW                        1049                       July 1999
Airbus A319-132                           N805AW                        1056                       July 1999
Airbus A319-132                           N806AW                        1071                      August 1999
Airbus A320-232                           N652AW                         953                     February 1999
Airbus A320-232                           N653AW                        1003                       May 1999
</TABLE>


















<PAGE>   19


                                 SCHEDULE II to
                             Note Purchase Agreement

                          PASS THROUGH TRUST AGREEMENTS

Pass Through Trust Agreement dated as of the Issuance Date between the Company
and the Pass Through Trustee in respect of America West Airlines Pass Through
Trust, Series 1998-1A-O.

Pass Through Trust Agreement dated as of the Issuance Date between the Company
and the Pass Through Trustee in respect of America West Airlines Pass Through
Trust, Series 1998-1B-O.

Pass Through Trust Agreement dated as of the Issuance Date between the Company
and the Pass Through Trustee in respect of America West Airlines Pass Through
Trust, Series 1998-1C-O.



<PAGE>   20


                                 SCHEDULE III to
                             Note Purchase Agreement

                               DEPOSIT AGREEMENTS

Deposit Agreement (Class A) dated as of the Issuance Date between the Depositary
and the Escrow Agent.

Deposit Agreement (Class B) dated as of the Issuance Date between the Depositary
and the Escrow Agent.

Deposit Agreement (Class C) dated as of the Issuance Date between the Depositary
and the Escrow Agent.



<PAGE>   21


                                 SCHEDULE IV to
                             Note Purchase Agreement

                       ESCROW AND PAYING AGENT AGREEMENTS

Escrow and Paying Agent Agreement (Class A) dated as of the Issuance Date among
the Escrow Agent, the Initial Purchasers, the Pass Through Trustee and the
Paying Agent.

Escrow and Paying Agent Agreement (Class B) dated as of the Issuance Date among
the Escrow Agent, the Initial Purchasers, the Pass Through Trustee and the
Paying Agent.

Escrow and Paying Agent Agreement (Class C) dated as of the Issuance Date among
the Escrow Agent, the Initial Purchasers, the Pass Through Trustee and the
Paying Agent.



<PAGE>   22



                                  SCHEDULE V to
                             Note Purchase Agreement

                            MANDATORY DOCUMENT TERMS

1.       May not modify in any material adverse respect the Granting Clause of
         the Trust Indenture Form so as to deprive the Note Holders of a
         security interest in and mortgage lien on the Aircraft and the Lease or
         to eliminate any of the "Secured Obligations" as defined therein or
         otherwise modify in any material adverse respect as regards the
         interests of the Note Holders, the Subordination Agent, the Liquidity
         Provider or the Mortgagee the provisions of Article II or III or
         Section 4.02, 4.03, 4.04, 5.02, 5.06, 9.01(b), 10.04 or 10.12 of the
         Trust Indenture Form.

2.       May not modify in any material adverse respect as regards the interests
         of the Note Holders, the Subordination Agent, the Liquidity Provider or
         the Mortgagee the provisions of Section 3.2.1(e), 3.3(c), 4.7, the
         final sentence of 7.1.1, 10.3.1(d)(ii), 13.3, 16, 17.3, 18.3 or 18.6(a)
         of the Lease Form or otherwise modify the terms of the Lease Form so as
         to deprive the Mortgagee of rights expressly granted to the "Mortgagee"
         therein.

3.       May not modify in any material adverse respect as regards the interests
         of the Note Holders, the Subordination Agent, the Liquidity Provider or
         the Mortgagee the provisions of Section 5.1.9, 5.1.10, 5.1.11, 5.1.12,
         7.5, 12, 15.7(a) or 15.9 of the Participation Agreement Form or of the
         provisions of Section 5.1.2(xxiii) or 10.1.1(a)(iv) of the
         Participation Agreement Form so as to eliminate the requirement to
         deliver to the Loan Participant or the Mortgagee, as the case may be,
         the legal opinions to be provided to such Persons thereunder
         (recognizing that the lawyers rendering such opinions may be changed)
         or of the provisions of Section 7.6.11(a)(ii) of the Participation
         Agreement Form as regards the rights of the Mortgagee thereunder or of
         the provisions of Section 5.1.16 of the Participation Agreement Form so
         as to deprive the Note Holders of a first priority security interest as
         provided therein in and mortgage lien on the Aircraft and the Lease or
         otherwise modify the terms of the Participation Agreement Form to
         deprive the Trustees, the Subordination Agent, the Liquidity Providers
         or the Mortgagee of any indemnity or right of reimbursement in its
         favor for Expenses or Taxes.

4.       May not modify, in any material adverse respect as regards the
         interests of the Note Holders, the Subordination Agent, the Liquidity
         Providers or the Mortgagee, the definition of "Make Whole Amount" in
         Annex A to the Note Purchase Agreement.

         Notwithstanding the foregoing, any such Mandatory Document Term may be
modified to correct or supplement any such provision which may be defective or
to cure any ambiguity or correct any mistake, provided that any such action
shall not materially adversely affect the interests of the Note Holders, the
Subordination Agent, the Liquidity Providers, the Mortgagee or the
Certificateholders.



<PAGE>   23


                                 SCHEDULE VI to
                             Note Purchase Agreement

                            MANDATORY ECONOMIC TERMS

Equipment Notes

Obligor:                            America West Airlines, Inc. or an Owner 
                                    Trust

Maximum Principal Amount:           the maximum principal amount of all the
                                    Equipment Notes issued with respect to an
                                    Aircraft may not exceed the maximum
                                    principal amount of Equipment Notes
                                    indicated for each such Aircraft as set
                                    forth in "Offering Memorandum Summary --
                                    Equipment Notes and the Aircraft" under the
                                    column "Maximum Principal Amount of
                                    Equipment Notes";

Initial Average Life:               the average life per aircraft of the Series
                                    A Equipment Notes shall not be less than 9.0
                                    years or extend beyond 13.5 years, of the
                                    Series B Equipment Notes shall not be less
                                    than 8.0 years or extend beyond 12.7 years,
                                    and of the Series C Equipment Notes shall
                                    not be less than 4.0 years or extend beyond
                                    8.5 years, in each case from the Issuance
                                    Date;

Average Life (in years):            as of the first Regular Distribution Date
                                    following the delivery of the last Aircraft
                                    to be delivered, the average life of the
                                    Class A Certificates, the Class B
                                    Certificates and the Class C Certificates
                                    shall not be less than, respectively, 11.0
                                    years, 10.0 years and 6.0 years or shall
                                    extend beyond, respectively, 12.9 years,
                                    11.4 years and 7.5 years from the Issuance
                                    Date;

Loan to Aircraft Value:             the loan to aircraft value ratio at the time
                                    of issuance of the Equipment Notes and on
                                    any Regular Distribution Date thereafter
                                    shall not exceed 43% in the case of the
                                    Series A Equipment Notes, 57% in the case of
                                    the Series B Equipment Notes and 71% in the
                                    case of the Series C Equipment Notes (in
                                    each case computed on the basis of an
                                    assumed value of such Aircraft no greater
                                    than the value for such Aircraft set forth
                                    under "Offering Memorandum Summary--
                                    Equipment Notes and the Aircraft" under the
                                    column "Appraised Value" and the
                                    Depreciation Assumption defined under
                                    "Offering Memorandum Summary-- Loan to
                                    Aircraft Value Ratios");

Final Maturity Date:                the final maturity date of (a) the Series A
                                    Equipment Notes may not be extended beyond
                                    January 2, 2017, (b) the Series B Equipment
                                    Notes may not be extended beyond January 2,
                                    2017 and (c) the Series C Equipment Notes
                                    may not be 


<PAGE>   24
                                                                               2

                                    extended beyond July 2, 2010;

Principal Amount:                   the original aggregate principal amount of
                                    all of the Equipment Notes of each Series
                                    shall not exceed the original aggregate face
                                    amount of the Certificates issued by the
                                    corresponding Trust;

Debt Rate:                          the interest rate applicable to each Series
                                    of Equipment Notes must be equal to the rate
                                    applicable to the Certificates issued by the
                                    corresponding Pass Through Trust;

Payment Due Rate:                   Debt Rate plus 1% per annum

Payment Dates:                      January 2 and July 2

Make-Whole Premiums:                as provided in Article II of the form of
                                    Trust Indenture marked as Exhibit A-3 of the
                                    Note Purchase Agreement (the "Trust
                                    Indenture Form")

Redemption and Purchase:            as provided in Article II of the Trust
                                    Indenture Form


Lease

Term:                               The Base Lease Term shall expire by its
                                    terms on or after final maturity date of the
                                    related Series A Equipment Notes

Lease Payment Dates:                January 2 and July 2 

Minimum Rent:                       Basic Rent due and payable on each Payment
                                    Date shall be at least sufficient to pay in
                                    full, as of such Payment Date (assuming
                                    timely payment of the related Equipment
                                    Notes prior to such Date), the aggregate
                                    principal amount of scheduled installments
                                    due on the related Equipment Notes
                                    outstanding on such Payment Date

Supplemental Rent:                  Sufficient to cover the sums described in
                                    clauses (a) through (d) of such term as
                                    defined in Annex A to the form of Lease (the
                                    "Lease Form") marked as Exhibit A-2 of the
                                    Note Purchase Agreement

EBO Amount (if any):                At all times equal to or greater than the
                                    then outstanding principal amount of the
                                    related Equipment Notes together with
                                    accrued interest thereon

Stipulated Loss Value:              At all times equal to or greater than the
                                    then outstanding principal amount of the
                                    related Equipment Notes together 


<PAGE>   25
                                                                               3


                                    with accrued interest thereon

Termination Value:                  At all times equal to or greater than the
                                    then outstanding principal amount of the
                                    related Equipment Notes together with
                                    accrued interest thereon

All-risk hull insurance:            not less than Stipulated Loss Value, subject
                                    to Lessee's right to self-insure on terms no
                                    more favorable to Lessee in any material
                                    respect than those set forth in Annex D of
                                    the form of Lease marked as Exhibit A-2.

Minimum Liability Insurance Amount: as set forth in Schedule 1 to the form of
                                    Lease marked as Exhibit A-2.

Payment Due Rate:                   as set forth in Annex A to the form of Lease
                                    marked as Exhibit A-2.

SLV Rate:                           as set forth in Schedule 1 to the form of 
                                    Lease marked as Exhibit A-2.


Participation Agreement

Mortgagee, Subordination Agent, Liquidity Providers, Pass Through Trustees, and
Escrow Agents indemnified against Expenses and Taxes to the extent set forth in
Section 9 of the form of the Participation Agreement (the "Participation Form")
marked as Exhibit A-1 to the Note Purchase Agreement



<PAGE>   26


                                 SCHEDULE VII to
                             Note Purchase Agreement

                         AGGREGATE AMORTIZATION SCHEDULE
<TABLE>
<CAPTION>
                               1998-1A Trust Scheduled      1998-1B Trust Scheduled      1998-1C Trust Scheduled
           Date                   Principal Payment            Principal Payment            Principal Payment
           ----                   -----------------            -----------------            -----------------
<S>                            <C>                          <C>                          <C>    
                               $                            $                            $
</TABLE>




<PAGE>   27

                                   ANNEX A to
                             Note Purchase Agreement

                                   DEFINITIONS

"Act" means 49 U.S.C. Sections 40101-46507.

"Adjusted Treasury Yield" means the Treasury Yield plus, in the case of a
distribution to holders of Class A Certificates, 225 basis points, in the case
of a distribution to holders of Class B Certificates, 250 basis points and, in
the case of a distribution to holders of Class C Certificates, 325 basis points.

"Affiliate" means, with respect to any person, any other person directly or
indirectly controlling, controlled by or under common control with such person.
For purposes of this definition, "control" means the power, directly or
indirectly, to direct or cause the direction of the management and policies of
such person, whether through the ownership of voting securities or by contract
or otherwise and "controlling," "controlled by" and "under common control with"
have correlative meanings.

"Aircraft" has the meaning set forth in the second recital to the Note Purchase
Agreement.

"Aircraft Purchase Agreement" means the Airbus A319/A320 Purchase Agreement,
dated as of September 12, 1997, between the Company and the Manufacturer
(including all exhibits thereto, together with all letter agreements entered
into that by their terms constitute part of any such Purchase Agreement).

"Aircraft Purchase Agreement Assignment" means an Assignment and Delegation
Agreement substantially in the form of Exhibit A-4 to the Note Purchase
Agreement.

"Assumed Amortization Schedule" means Schedule VII to the Note Purchase 
Agreement.

"Average Life Date" means, for any Equipment Note, the date which follows the
time of determination by a period equal to the Remaining Weighted Average Life
of such Equipment Note.

"Bankruptcy Code" means the United States Bankruptcy Code, 11 U.S.C.
Sections 102 et seq.

"Business Day" means any day, other than a Saturday, Sunday or other day on
which commercial banks are authorized or required by law to close in New York,
New York, Phoenix, Arizona, Hartford, Connecticut or Wilmington, Delaware.

"Certificate" has the meaning set forth in the third recital to the Note
Purchase Agreement.

"Certificateholder" means the Person in whose name a Certificate is registered
in the Register.

"Class" means the class of Certificates issued by each Pass Through Trust.

"Company" means America West Airlines, Inc., a Delaware corporation.


<PAGE>   28
                                                                               2

"Corporate Trust Office" with respect to any Pass Through Trustee or any Loan
Trustee, means the office of such trustee in the city at which at any particular
time its corporate trust business shall be principally administered.

"Cut-off Date" means the earlier of (a) the day after the Delivery Period
Termination Date and (b) the date on which a Triggering Event occurs.

"Delivery Period Termination Date" means the earlier of (a) November 30, 1999,
or, if the Equipment Notes relating to all of the Aircraft (or Substitute
Aircraft in lieu thereof) have not been purchased by the Pass Through Trustees
on or prior to such date due to any reason beyond the control of the Company and
not occasioned by the Company's fault or negligence, January 31, 2000 and (b)
the date on which Equipment Notes issued with respect to all of the Aircraft (or
Substitute Aircraft in lieu thereof) have been purchased by the Pass Through
Trustees in accordance with the Note Purchase Agreement.

"Delivery Date" means the Business Day on which an Aircraft is delivered to and
accepted by the Company or otherwise becomes subject to any Financing Agreement.

"Deposit" has the meaning set forth in the fifth recital to the Note Purchase
Agreement.

"Deposit Agreement" has the meaning set forth in the fifth recital to the Note
Purchase Agreement.

"Deposit Make-Whole Premium" means, with respect to the distribution of unused
Deposits to holders of any Class of Certificates, as of any date of
determination, an amount equal to the excess, if any, of (a) the present value
of the excess of (i) the scheduled payment of principal and interest to maturity
of the Equipment Notes, assuming the maximum principal amount thereof (the
"Maximum Amount") minus any Non-Premium Amount and, in the case of Class C
Certificates only, the Par Redemption Amount were issued, on each remaining
Regular Distribution Date for such Class under the Assumed Amortization Schedule
over (ii) the scheduled payment of principal and interest to maturity of the
Equipment Notes actually acquired by the Pass Through Trustee for such Class on
each such Regular Distribution Date, such present value computed by discounting
such excess on a semiannual basis on each Regular Distribution Date (assuming a
360-day year of twelve 30-day months) using a discount rate equal to the
Adjusted Treasury Yield over (b) the amount of such unused Deposits to be
distributed to the holders of such Certificates minus any Non-Premium Amount
and, in the case of Class C Certificates only, the Par Redemption Amount (the
remainder of such subtraction, the "Net Deposits") plus accrued and unpaid
interest on the Net Deposits to but excluding such date of determination from
and including the preceding Regular Distribution Date (or if such date of
determination precedes the first Regular Distribution Date, the Issuance Date).

"Depositary" means ABN AMRO Bank N.V., a banking institution organized under the
laws of the Netherlands, acting through its Chicago branch.

"Equipment Notes" means and includes any equipment notes issued under any
Indenture in the form specified in Section 2.01 thereof (as such form may be
varied pursuant to the terms of such Indenture) and any Equipment Note issued
under any Indenture in exchange for or replacement of any other Equipment Note.


<PAGE>   29
                                                                               3


"Escrow Agent" has the meaning set forth in the first paragraph of the Note
Purchase Agreement.

"Escrow and Paying Agent Agreement" has the meaning set forth in the fifth
recital to the Note Purchase Agreement.

"FAA" means the Federal Aviation Administration of the United States.

"Final Withdrawal" with respect to each Escrow and Paying Agent Agreement, has
the meaning set forth in Section 1.02 thereof.

"Financing Agreements" means, collectively, the Lease Financing Agreements and
the Owner Financing Agreements.

"Government Entity" means (a) any federal, state, provincial or similar
government, and any body, board, department, commission, court, tribunal,
authority, agency or other instrumentality of any such government or otherwise
exercising any executive, legislative, judicial, administrative or regulatory
functions of such government or (b) any other government entity having
jurisdiction over any matter contemplated by the Operative Agreements or
relating to the observance or performance of the obligations of any of the
parties to the Operative Agreements.

"H.15(519)" means the weekly statistical release designated as such, or any
successor publication, published by the Board of Governors of the Federal
Reserve System.

"Indentures" means, collectively, the Leased Aircraft Indentures and the Owned
Aircraft Indentures.

"Initial Purchasers" has the meaning set forth in the fourth recital to the Note
Purchase Agreement.

"Intercreditor Agreement" has the meaning set forth in the ninth recital to the
Note Purchase Agreement.

"Issuance Date" means the date of the original issuance of the Certificates.

"Law" means (a) any constitution, treaty, statute, law, decree, regulation,
order, rule or directive of any Government Entity, and (b) any judicial or
administrative interpretation or application of, or decision under, any of the
foregoing.

"Lease" means a Lease Agreement substantially in the form of Exhibit A-2 to the
Note Purchase Agreement.

"Lease Financing Agreements" means, collectively, the Aircraft Purchase
Agreement Assignment, the Leased Aircraft Participation Agreement, the Lease,
the Leased Aircraft Indenture, the Equipment Notes issued thereunder and the
Trust Agreement relating to the financing of a Leased Aircraft.

"Leased Aircraft" means an Aircraft subject to a Lease.


<PAGE>   30
                                                                               4


"Leased Aircraft Indenture" means a Trust Indenture and Mortgage substantially
in the form of Exhibit A-3 to the Note Purchase Agreement.

"Leased Aircraft Participation Agreement" means a Participation Agreement
substantially in the form of Exhibit A-1 to the Note Purchase Agreement.

"Liquidity Facility" has the meaning set forth in the ninth recital to the Note
Purchase Agreement.

"Liquidity Provider" has the meaning set forth in the ninth recital to the Note
Purchase Agreement.

"Loan Trustee" means the "Mortgagee" as defined in the Financing Agreements.

"Mandatory Document Terms" means the terms set forth on Schedule V to the Note
Purchase Agreement.

"Mandatory Economic Terms" means the terms set forth on Schedule VI to the Note
Purchase Agreement.

"Manufacturer" means AVSA, S.A.R.L., solely in its capacity as manufacturer or
seller of Aircraft.

"Material Adverse Change" means, with respect to any Person, any event,
condition or circumstance that materially and adversely affect such Person 's
business or consolidated financial condition or its ability to observe or
perform its obligations, liabilities and agreements under the Operative
Agreements.

"Non-Premium Amount" means, with respect to any Class of Certificates, if any
Aircraft has not been delivered by the Manufacturer on or prior to the Delivery
Period Termination Date due to any reason not occasioned by the Company's fault
or negligence and no Substitute Aircraft has been provided in lieu of such
Aircraft, an amount equal to the maximum principal amount of Equipment Notes
with respect to such Aircraft that could have been issued and acquired by the
Pass Through Trust that issued such Class of Certificates in accordance with the
Mandatory Economic Terms.

"Note Purchase Agreement" means the Note Purchase Agreement to which this Annex
A is attached.

"Notice of Purchase Withdrawal" with respect to each Deposit Agreement, has the
meaning set forth in Section 2.3 thereof.

"Operative Agreements" means, collectively, the Pass Through Trust Agreements,
the Escrow and Paying Agent Agreements, the Deposit Agreements, the Liquidity
Facilities, the Intercreditor Agreement, the Registration Rights Agreements, the
Trust Agreements, the Equipment Notes, the Certificates and the Financing
Agreements.


<PAGE>   31
                                                                               5


"Owned Aircraft Indenture" means a Trust Indenture and Mortgage substantially in
the form of Exhibit C-2 to the Note Purchase Agreement.

"Owned Aircraft Participation Agreement" means a Participation Agreement
substantially in the form of Exhibit C-1 to the Note Purchase Agreement.

"Owner Financing Agreements" means, collectively, the Owned Aircraft
Participation Agreement, the Owned Aircraft Indenture and the Equipment Notes
issued thereunder.

"Owner Participant" means, with respect to any Leased Aircraft, the Person named
as the Owner Participant in the Participation Agreement with respect to such
Leased Aircraft.

"Owner Trust" means with respect to any Leased Aircraft, the trust created by
the "Trust Agreement" referred to in the Leased Aircraft Indenture related
thereto.

"Owner Trustee" means with respect to any Leased Aircraft, the "Owner Trustee"
party to the "Trust Agreement" referred to in the Leased Aircraft Indenture
related thereto.

"Par Redemption Amount" means $5,000,000.

"Participation Agreements" means, collectively, the Leased Aircraft
Participation Agreements and the Owned Aircraft Participation Agreements.

"Pass Through Trust" has the meaning set forth in the third recital to the Note
Purchase Agreement.

"Pass Through Trust Agreement" has the meaning set forth in the third recital to
the Note Purchase Agreement.

"Pass Through Trustee" has the meaning set forth in the first paragraph of the
Note Purchase Agreement.

"Paying Agent" has the meaning set forth in the first paragraph of the Note
Purchase Agreement.

"Person" means any individual, firm, partnership, joint venture, trust, trustee,
Government Entity, organization, association, corporation, government agency,
committee, department, authority and other body, corporate or incorporate,
whether having distinct legal status or not, or any member of any of the same.

"Qualified Owner Participant" means any bank, trust company, insurance company,
financial institution, limited liability company, partnership or corporation, in
each case with a combined capital and surplus or net worth of at least
$50,000,000.

"Rating Agencies" means, collectively, at any time, each nationally recognized
rating agency which shall have been requested to rate the Certificates and which
shall then be rating the Certificates. The initial Rating Agencies will be
Moody's Investors Service, Inc. and Standard & Poor's Rating Group, a division
of McGraw-Hill Inc.


<PAGE>   32
                                                                               6


"Rating Agency Confirmation" means, with respect to any Financing Agreement that
has been modified in any material respect from the forms thereof attached to the
Note Purchase Agreement or with respect to Substitute Aircraft, a written
confirmation from each of the Rating Agencies that the use of such Financing
Agreement with such modifications or the substituting of such Substitute
Aircraft for an Aircraft, whichever of the foregoing shall in a particular case
require Rating Agency Confirmation, would not result in (i) a reduction of the
rating for any Class of Certificates below the then current rating for such
Class of Certificates or (ii) a withdrawal or suspension of the rating of any
Class of Certificates.

"Register" means the register maintained pursuant to Sections 3.04 and 7.12 of
each Pass Through Trust Agreement.

"Registration Rights Agreement" means the Exchange and Registration Rights
Agreement dated as of the Issuance Date, among the Initial Purchasers, the Pass
Through Trustees and the Company, as amended, supplemented or otherwise modified
from time to time in accordance with its terms.

"Regular Distribution Dates" shall mean January 2 and July 2 of each year,
commencing January 2, 1999.

"Remaining Weighted Average Life" means, on a given date with respect to any
Equipment Note, the number of days equal to the quotient obtained by dividing
(a) the sum of each of the products obtained by multiplying (i) the amount of
each then remaining scheduled payment of principal of such Equipment Note by
(ii) the number of days from and including such determination date to but
excluding the date on which such payment of principal is scheduled to be made,
by (b) the then outstanding principal amount of such Equipment Note.

"Scheduled Delivery Date" has the meaning set forth in Section 1(b) hereof.

"Section 1110" means 11 U.S.C. Section 1110 of the Bankruptcy Code or any
successor or analogous Section of the federal bankruptcy Law in effect from time
to time.

"Series A Equipment Notes" means Equipment Notes issued under an Indenture and
designated as "Series A" thereunder.

"Series B Equipment Notes" means Equipment Notes issued under an Indenture and
designated as "Series B" thereunder.

"Series C Equipment Notes" means Equipment Notes issued under an Indenture and
designated as "Series C" thereunder.

"Subordination Agent" has the meaning set forth in the first paragraph of the
Note Purchase Agreement.

"Substitute Aircraft" has the meaning set forth in Section 1(f) of the Note
Purchase Agreement.

"Taxes" means all license, recording, documentary, registration and other
similar fees and all taxes, levies, imposts, duties, charges, assessments or
withholdings of any nature whatsoever 


<PAGE>   33
                                                                               7


imposed by any Taxing Authority, together with any penalties, additions to tax,
fines or interest thereon or additions thereto.

"Taxing Authority" means any federal, state or local government or other taxing
authority in the United States, any foreign government or any political
subdivision or taxing authority thereof, any international taxing authority or
any territory or possession of the United States or any taxing authority
thereof.

"Treasury Yield" means, as of any date of determination, with respect to any
Equipment Note (utilizing the Assumed Amortization Schedule applicable thereto),
the interest rate (expressed as a decimal and, in the case of United States
Treasury bills, converted to a bond equivalent yield) determined to be the per
annum rate equal to the semi-annual yield to maturity for United States Treasury
securities maturing on the Average Life Date (of such Equipment Note) and
trading in the public securities markets either as determined by interpolation
between the most recent weekly average yield to maturity for two series of
United States Treasury securities, trading in the public securities markets, (A)
one maturing as close as possible to, but earlier than, the Average Life Date
(of such Equipment Note) and (B) the other maturing as close as possible to, but
later than, the Average Life Date (of such Equipment Note), in each case as
published in the most recent H.15(519) or, if a weekly average yield to maturity
for United States Treasury securities maturing on the Average Life Date (of such
Equipment Note) is reported on the most recent H.15(519), such weekly average
yield to maturity as published in such H.15(519).

"Triggering Event" has the meaning assigned to such term in the Intercreditor
Agreement.

"Trust Agreement" means a Trust Agreement substantially in the form of Exhibit
A-5 to the Note Purchase Agreement.

"Unindemnified Taxes" has the meaning assigned to such term in the Intercreditor
Agreement.

"WTC" has the meaning set forth in the first paragraph of the Note Purchase
Agreement.



<PAGE>   34



                                 EXHIBIT A-1 to
                             Note Purchase Agreement

                 FORM OF LEASED AIRCRAFT PARTICIPATION AGREEMENT



<PAGE>   35





                                 EXHIBIT A-2 to
                             Note Purchase Agreement

                                  FORM OF LEASE



<PAGE>   36


                                 EXHIBIT A-3 to
                             Note Purchase Agreement

                        FORM OF LEASED AIRCRAFT INDENTURE



<PAGE>   37




                                 EXHIBIT A-4 to
                             Note Purchase Agreement

                 FORM OF AIRCRAFT PURCHASE AGREEMENT ASSIGNMENT



<PAGE>   38

                                 EXHIBIT A-5 to
                             Note Purchase Agreement

                     FORM OF LEASED AIRCRAFT TRUST AGREEMENT



<PAGE>   39


                                  EXHIBIT B to
                             Note Purchase Agreement

                             FORM OF DELIVERY NOTICE

                         Dated as of __________ __, 199_

To each of the addressees listed

         in Schedule A hereto

                  Re:      Delivery Notice in accordance with Note Purchase
                           Agreement referred to below

Gentlemen:

         Reference is made to the Note Purchase Agreement dated as of October 6,
1998 among America West Airlines, Inc. (the "Company"), Wilmington Trust
Company, as Pass Through Trustee under each of the Pass Through Trust Agreements
(as defined therein) (the "Pass Through Trustee"), Wilmington Trust Company, as
Subordination Agent (the "Subordination Agent"), Wilmington Trust Company, as
Escrow Agent (the "Escrow Agent") and Wilmington Trust Company, as Paying Agent
(the "Paying Agent") (as in effect from time to time, the "Note Purchase
Agreement"). Unless otherwise defined herein, capitalized terms used herein
shall have the meanings set forth in the Note Purchase Agreement or, to the
extent not defined therein, the Intercreditor Agreement.

         Pursuant to Section 1(b) of the Note Purchase Agreement, the
undersigned hereby notifies you, in respect of the Airbus ___ aircraft with
manufacturer's serial number _______ (the "Aircraft"), of the following:

(1)      The Company has elected to treat the Aircraft as a
         [Leased](1)/[Owned](2) Aircraft;

(2)      The Scheduled Delivery Date of the Aircraft is __________ __, 199_; and

(3)      The aggregate amount of each series of Equipment Notes to be issued,
         and purchased by the respective Pass Through Trustees, on the Scheduled
         Delivery Date, in connection with the financing of such Aircraft is as
         follows:

         (a)      the Class A Trustee shall purchase Series A Equipment Notes in
                  the amount of $__________;
__________________

1        To be inserted in the case of a Leased Aircraft.

2        To be inserted in the case of an Owned Aircraft.


<PAGE>   40

                                                                               2


         (b)      the Class B Trustee shall purchase Series B Equipment Notes in
                  the amount of $__________; and

         (c)      the Class C Trustee shall purchase Series C Equipment Notes in
                  the amount of $__________.

         The Company hereby instructs the Class A Trustee to (i) execute a
Withdrawal Certificate in the form of Annex A hereto dated _____ __, 199_ [a
date which is no later than one Business Day prior to the Scheduled Delivery
Date] and attach thereto a Notice of Purchase Withdrawal dated such date
completed as set forth on Exhibit A hereto and (ii) deliver such Withdrawal
Certificate and Notice of Purchase Withdrawal to the applicable Escrow Agent.

         The Company hereby instructs the Class B Trustee to (i) execute a
Withdrawal Certificate in the form of Annex A hereto dated _____ __, 199_ [a
date which is no later than one Business Day prior to the Scheduled Delivery
Date] and attach thereto a Notice of Purchase Withdrawal dated such date
completed as set forth on Exhibit B hereto and (ii) deliver such Withdrawal
Certificate and Notice of Purchase Withdrawal to the applicable Escrow Agent.

         The Company hereby instructs the Class C Trustee to (i) execute a
Withdrawal Certificate in the form of Annex A hereto dated _____ __, 199_ [a
date which is no later than one Business Day prior to the Scheduled Delivery
Date] and attach thereto a Notice of Purchase Withdrawal dated such date
completed as set forth on Exhibit C hereto and (ii) deliver such Withdrawal
Certificate and Notice of Purchase Withdrawal to the applicable Escrow Agent.

         The Company hereby instructs each Pass Through Trustee to (i) purchase
Equipment Notes of a series and in an amount set forth opposite such Pass
Through Trustee in clause (3) above with a portion of the proceeds of the
withdrawals of Deposits referred to in the applicable Notice of Purchase
Withdrawal referred to above and (ii) re-deposit with the Depositary the excess,
if any, of the amount so withdrawn over the purchase price of such Equipment
Notes.

         The Company hereby instructs each Pass Through Trustee to (a) enter
into the Participation Agreement dated as of _____ __, 199_ among the Company,
as [Lessee](3)/[Owner](4), the Subordination Agent, the Pass Through Trustee,
___________________, as Mortgagee [and Loan Participant, _____________________,
as Owner Trustee and _________, as Owner Participant](5), (b) perform its
obligations thereunder and (c) deliver such certificates, documents and legal
opinions relating to such Pass Through Trustee as required thereby.

         [The Company hereby certifies that the Owner Participant with respect
to the Aircraft is (a) not an Affiliate of the Company and (b) a [Qualified
Owner Participant/person whose 
________________________

3 To be inserted in the case of a Leased Aircraft.

4 To be inserted in the case of an Owned Aircraft.

5 To be inserted in the case of a Leased Aircraft.


<PAGE>   41
                                                                               3


obligations under the Owner Participant Agreements (as defined in the
Participation Agreement) are guaranteed by a Qualified Owner Participant].](6)

Yours faithfully,

America West Airlines, Inc.

By:                                                  
   ----------------------------------
      Name:
      Title:
_______________________

6        To be inserted in the case of a Leased Aircraft.


<PAGE>   42

                                   SCHEDULE A



Wilmington Trust Company, as
   Pass Through Trustee, Subordination
   Agent, Escrow Agent and Paying Agent
Rodney Square North
1100 North Market Street
Wilmington, Delaware 19890
Attention: Corporate Trust
           Administration
Facsimile: (302) 651-8882

Standard & Poor's Ratings Service
25 Broadway, 16th Floor
New York, New York  10004
Attention:  Michael K. Vernier
Facsimile:  (212) 208-0300

Moody's Investors Service, Inc.
99 Church Street
New York, New York  10007
Attention:  Martine Nowicki
Facsimile:  (212) 553-4600



<PAGE>   43

                                                                         ANNEX A

                             WITHDRAWAL CERTIFICATE

                                 (Class __)(7)

Wilmington Trust Company,
as Escrow Agent

Dear Sirs:

                  Reference is made to the Escrow and Paying Agent Agreement,
dated as of October 6, 1998 (the "Agreement"). We hereby certify to you that the
conditions to the obligations of the undersigned to execute a Participation
Agreement pursuant to the Note Purchase Agreement have been satisfied. Pursuant
to Section 1.02(c) of the Agreement, please execute the attached Notice of
Withdrawal and immediately transmit by facsimile to the Depositary, at (312)
606-8428.

                                        Very truly yours,

                                        WILMINGTON TRUST COMPANY, not in its 
                                        individual capacity by solely as Pass 
                                        Through Trustee



                                        By:_____________________________________
                                           Name:
                                           Title:

Dated: _______ __, 199_

_________________________

7        Insert letter of appropriate class of Certificates.


<PAGE>   44


                                                                       EXHIBIT A

                          NOTICE OF PURCHASE WITHDRAWAL

ABN AMRO BANK N.V.,
  Chicago Branch
135 South LaSalle Street
Chicago, Illinois  60603
Attention:  Vice President - Aerospace
Telecopier: (312) 606-8428

Gentlemen:

                  Reference is made to (i) the Deposit Agreement (Class A) dated
as of October 6, 1998 (the "Deposit Agreement") between Wilmington Trust
Company, as Escrow Agent, and ABN AMRO Bank N.V., Chicago Branch, as Depositary
(the "Depositary").

                  In accordance with Section 2.3(a) of the Deposit Agreement,
the undersigned hereby requests the withdrawal of the entire amount of the
Deposit, $_______, Account No. ____________.

                  The undersigned hereby directs the Depositary to pay the
proceeds of the Deposit to [________________, Account No. _____, Reference:
_________] on _________ __, 199_, upon the telephonic request of a
representative of the Pass Through Trustee.

                                        WILMINGTON TRUST COMPANY,
                                        as Escrow Agent



                                        By:_____________________________________
                                           Name:
                                           Title:

Dated: _______ __, 199_



<PAGE>   45


                                                                       EXHIBIT B

                          NOTICE OF PURCHASE WITHDRAWAL

ABN AMRO BANK N.V.,
  Chicago Branch
135 South LaSalle Street
Chicago, Illinois  60603
Attention:  Vice President - Aerospace
Telecopier: (312) 606-8428

Gentlemen:

                  Reference is made to (i) the Deposit Agreement (Class B) dated
as of October 6, 1998 (the "Deposit Agreement") between Wilmington Trust
Company, as Escrow Agent, and ABN AMRO Bank N.V., Chicago Branch, as Depositary
(the "Depositary").

                  In accordance with Section 2.3(a) of the Deposit Agreement,
the undersigned hereby requests the withdrawal of the entire amount of the
Deposit, $_______, Account No. ____________.

                  The undersigned hereby directs the Depositary to pay the
proceeds of the Deposit to [________________, Account No. _____, Reference:
_________] on _________ __, 199_, upon the telephonic request of a
representative of the Pass Through Trustee.

                                        WILMINGTON TRUST COMPANY,
                                        as Escrow Agent



                                        By:_____________________________________
                                           Name:
                                           Title:

Dated: _______ __, 199_



<PAGE>   46



                                                                       EXHIBIT C

                          NOTICE OF PURCHASE WITHDRAWAL

ABN AMRO BANK N.V.,
  Chicago Branch
135 South LaSalle Street
Chicago, Illinois  60603
Attention:  Vice President - Aerospace
Telecopier: (312) 606-8428

Gentlemen:

                  Reference is made to (i) the Deposit Agreement (Class C) dated
as of October 6, 1998 (the "Deposit Agreement") between Wilmington Trust
Company, as Escrow Agent, and ABN AMRO Bank N.V., Chicago Branch, as Depositary
(the "Depositary").

                  In accordance with Section 2.3(a) of the Deposit Agreement,
the undersigned hereby requests the withdrawal of the entire amount of the
Deposit, $_______, Account No. ____________.

                  The undersigned hereby directs the Depositary to pay the
proceeds of the Deposit to [________________, Account No. _____, Reference:
_________] on _________ __, 199_, upon the telephonic request of a
representative of the Pass Through Trustee.

                                        WILMINGTON TRUST COMPANY,
                                        as Escrow Agent



                                        By:_____________________________________
                                           Name:
                                           Title:

Dated: _______ __, 199_



<PAGE>   47



                                 EXHIBIT C-1 to
                             Note Purchase Agreement

                 FORM OF OWNED AIRCRAFT PARTICIPATION AGREEMENT



<PAGE>   48





                                 EXHIBIT C-2 to
                             Note Purchase Agreement

                        FORM OF OWNED AIRCRAFT INDENTURE






<PAGE>   1
                [MORRIS, JAMES, HITCHENS & WILLIAMS LETTERHEAD]

                                                                     Exhibit 5.1

December 16, 1998

America West Airlines, Inc.
51 W. Third Street
Tempe, Arizona 85281

RE: AMERICA WEST AIRLINES PASS THROUGH CERTIFICATES, SERIES 1998-1

Ladies and Gentlemen:

         You have asked us to provide you with an opinion in connection with the
filing of a registration statement on Form S-4 (the "Registration Statement")
with the Securities and Exchange Commission pursuant to the Securities Act of
1933, as amended (the "Securities Act"), in respect of the registration under
the Securities Act of the Pass Through Certificates, Series 1998-1A (the "New
Class A Certificates"), the Pass Through Certificates, Series 1998-1B (the "New
Class B Certificates") and the Pass Through Certificates, Series 1998-1C (the
"New Class C Certificates" and, together with the New Class A Certificates and
the New Class B Certificates, the "New Certificates"), to be offered in exchange
for all outstanding Pass Through Certificates, Series 1998-1A, Series 1998-1B
and Series 1998-1C (collectively, the "Old Certificates"). Each of the New Class
A Certificates, the New Class B Certificates and the New Class C Certificates
represents or will represent a fractional undivided interest in on of the
following corresponding pass through trusts: the America West Airlines Pass
Through Trust, Series 1998-1A-O, the America West Airlines Pass Through Trust,
Series 1998-1A-S, the America West Airlines Pass Through Trust, Series
1998-1B-O, the America West Airlines Pass Through Trust, Series 1998-1B-S, the
America West Airlines Pass Through Trust, Series 1998-1C-O and the America West
Airlines Pass Through Trust, Series 1998-1C-S (collectively, the "Trusts"). The
Trusts were formed pursuant to three separate pass through trust agreements,
dated as of October 6, 1998 (the "Pass Through Trust Agreements"), between
America West Airlines, Inc. ("America West" or the "Company") and Wilmington
Trust Company, as pass through trustee under each Trust (the "Trustee"). In its
individual capacity, Wilmington Trust Company is herein referred to as
"Wilmington Trust").

         In connection with this opinion letter, we have examined the
Registration Statement, including the Prospectus that forms a part of the
Registration Statement. We have also examined executed counterparts, forms or
copies otherwise identified to our satisfaction of the following documents: the
Pass Through Trust Agreements, the Exchange and Registration Rights Agreement,
dated October 6, 1998 (the "Registration Rights Agreement"), and the forms of
Old Certificates and New Certificates, each filed as an exhibit to the
Registration Statement (collectively, the "Documents"). We have also examined
and relied on originals or copies of such other documents, such corporate
records, certificates and other statements of governmental officials and
corporate officers and other representatives of the corporations or entities
referred to herein and such other instruments as we have deemed necessary or
appropriate for the


<PAGE>   2

America West Airlines, Inc.
December 16, 1998
Page Two

purposes of this opinion. Moreover, as to certain facts material to the opinions
expressed herein, we have relied upon the representations and warranties
contained in the Documents.

         Based on the foregoing and upon an examination of such questions of law
as we have considered necessary or appropriate, and subject to the assumptions,
exceptions and qualifications set forth herein, we advise you that, in our
opinion:

         1. When issued in exchange for the Old Certificates pursuant to the
Registration Rights Agreement and authenticated pursuant to the Pass Through
Trust Agreements, the New Certificates will be duly authorized, legal, valid and
binding obligations of the Trusts, enforceable against the Trusts in accordance
with their terms and the terms of the Pass Through Trust Agreements and will be
entitled to the benefits of the Pass Through Trust Agreements.

         The foregoing opinion is subject to the following assumptions,
exceptions and qualifications:

         A. The foregoing opinion is limited to the laws of the State of
Delaware and the federal laws of the United States of America governing the
banking and trust powers of Wilmington Trust. In addition, we express no opinion
with respect to (i) federal securities laws, including without limitation the
Securities Act, the Securities Exchange Act of 1934, as amended, the Investment
Company Act of 1940, as amended, and the Trust Indenture Act of 1939, as
amended, (ii) Part A of Subtitle VII of Title 49 of the United States Code, as
amended, (iii) the Federal Communications Act of 1934, as amended, (iv) state
securities or blue sky laws, or (v) laws, rules and regulations applicable for
the particular nature of the equipment acquired by the Company. Insofar as the
foregoing opinions relate to the validity and enforceability of the Documents
which are expressed to be governed by the laws of any state other than the State
of Delaware, we have assumed that each such document is legal, valid, binding
and enforceable in accordance with its terms under such laws (as to which we
express no opinion).

         B. The foregoing opinion regarding enforceability of any document are
subject to (i) applicable bankruptcy, insolvency, moratorium, reorganization,
fraudulent conveyance, receivership and similar laws relating to or affecting
the rights and remedies of creditors generally, and (ii) general principles of
equity (regardless of whether such enforceability is considered and applied in a
proceeding in equity or at law).

         C. We have assumed the due authorization, execution and delivery by
each of the parties thereto (other than Wilmington Trust in its individual
capacity, or as Trustee, as the case may be) of the Documents to which each is a
party and that each of such parties has the full power, authority and legal
right to execute, delivery and perform each such document.

         D. We have assumed that all signatures (other than those of Wilmington
Trust in its individual capacity, or as Trustee, as the case may be) on
documents and instruments examined 


<PAGE>   3

America West Airlines, Inc.
December 16, 1998
Page Three

by us are genuine, that all documents and instruments submitted to us as
originals are authentic, and that all documents and instruments submitted to us
as copies or specimens conform with the originals, which facts we have not
independently verified.

         E. We have not participated in the preparation of the Registration
Statement or the Prospectus that forms a part of the Registration Statement and
assume no responsibility for their contents.

         This opinion may be relied upon by you in connection with the matters
set forth herein. Without our prior written consent, this opinion may not be
furnished or quoted to, or relied upon by, any other person or entity for any
purpose. Notwithstanding the foregoing, we hereby consent to the filing of this
opinion as an exhibit to the Registration Statement and to the reference to this
Firm under the headings "Legal Matters" in the Prospectus included in the
Registration Statement. In giving such consent, we do not thereby admit that we
are "experts" within the meaning of the Securities Act or the rules and
regulations of the Securities and Exchange Commission issued thereunder with
respect to any part of the Registration Statement, including this exhibit.


                                       Very truly yours,


                                       /s/ Morris, James, Hitchens & Williams


<PAGE>   1
                                                                    EXHIBIT 12.1

                           AMERICA WEST AIRLINES, INC.

                COMPUTATION OF RATIO OF EARNINGS TO FIXED CHARGES
            (IN THOUSANDS EXCEPT RATIO OF EARNINGS TO FIXED CHARGES)

<TABLE>
<CAPTION>
                                                                           REORGANIZED COMPANY                                    
                                           -----------------------------------------------------------------------------------    
                                              NINE MONTHS ENDED                                              
                                                SEPTEMBER 30,               YEAR ENDED DECEMBER 31,             PERIOD FROM       
                                           ----------------------    ------------------------------------       AUGUST 26 TO      
                                              1998         1997         1997         1996          1995      DECEMBER 31, 1994    
                                              ----         ----         ----         ----          ----      -----------------    
<S>                                        <C>          <C>          <C>          <C>           <C>          <C>                  
Computation of Earnings:
Income (loss) before income taxes
  and extraordinary item                   $ 153,873    $ 104,286    $ 140,673    $  34,493     $ 108,378        $  19,736        

Add:
   Interest expense including
     amortization of debt expense             26,826       30,184       39,620       49,678        59,418           22,827        
   Interest portion of rent expense           81,383       76,570      102,805       93,539        83,680           26,879        
                                           ---------    ---------    ---------    ---------     ---------        ---------        
Income (loss), as adjusted                 $ 262,082    $ 211,040    $ 283,098    $ 177,710     $ 251,476        $  69,442        
                                           =========    =========    =========    =========     =========        =========        


Computation of Fixed Charges:
Interest expense including amortization
  of debt expense                          $  26,826    $  30,184    $  39,620    $  49,678     $  59,418        $  22,827        
Interest portion of rent expense              81,383       76,570      102,805       93,539        83,680           26,879        
Capitalized interest                           3,324           40          553           --         2,666              621        
                                           ---------    ---------    ---------    ---------     ---------        ---------        
Fixed charges                              $ 111,533    $ 106,794    $ 142,978    $ 143,217     $ 145,764        $  50,327        
                                           =========    =========    =========    =========     =========        =========        


Ratio of earnings to fixed charges              2.35         1.98         1.98         1.24          1.73             1.38        
</TABLE>

<TABLE>
<CAPTION>
                                                 PREDECESSOR COMPANY     
                                           -------------------------------
                                           
                                            PERIOD FROM        YEAR ENDED
                                            JANUARY 1 TO      DECEMBER 31,
                                           AUGUST 25, 1994        1993
                                           ---------------        ----
<S>                                        <C>                 <C>      
Computation of Earnings:
Income (loss) before income taxes
  and extraordinary item                      $(201,209)       $  37,924

Add:
   Interest expense including
     amortization of debt expense                34,038           54,252
   Interest portion of rent expense              51,538           81,795
                                              ---------        ---------
Income (loss), as adjusted                    $(115,633)       $ 173,971
                                              =========        =========


Computation of Fixed Charges:
Interest expense including amortization
  of debt expense                             $  34,038        $  54,252
Interest portion of rent expense                 51,538           81,795
Capitalized interest                                 --               --
                                              ---------        ---------
Fixed charges                                 $  85,576        $ 136,047
                                              =========        =========


Ratio of earnings to fixed charges                ( * )             1.28
</TABLE>


(*)  For the purpose of computing the ratio of earnings to fixed charges,
     "earnings" consist of income (loss) before income taxes and extraordinary
     item plus fixed charges less capitalized interest. "Fixed charges" consist
     of interest expense including amortization of debt expense, one-third of
     rent expense, which is deemed to be representative of an interest factor,
     and capitalized interest. For the period ended August 25, 1994 earnings
     were insufficient to cover fixed charges by $201.2 million.

<PAGE>   1
 
                                                                    EXHIBIT 23.2
 
The Board of Directors
America West Airlines, Inc.:
 
We consent to the use of our reports incorporated herein by reference and to the
references to our firm under the headings "Selected Financial Data" and
"Experts" in the prospectus.
 
KPMG LLP
 
Phoenix, AZ
February 1, 1999

<PAGE>   1
                                  [Letterhead of AVITAS]

                                                                    Exhibit 23.3

December 16, 1998


America West Airlines, Inc.
51 West Third Street
Tempe, AZ  85281


Re:      America West Airlines, Inc.
         Pass Through Certificates, Series 1998-1


Ladies and Gentlemen:

         We consent to the reference to our name in the text under the headings
"Risk Factors - Risk Factors Relating to the Certificates and the Exchange Offer
- - Possible Effects if Aircraft Appraisals do not Correspond to the Realizable
Value of Aircraft," "Description of the Aircraft and the Appraisals - The
Appraisals", "Experts" and "Appendix II - Appraisal Letters" in the Registration
Statement on Form S-4 being filed with the Securities and Exchange Commission.
We also consent to the inclusion in the Registration Statement of the report
prepared by us with respect to the Aircraft referred to therein.


Sincerely,

/s/ Noel Petrie
- --------------------------
Noel Petrie
Manager -- Asset Valuation

<PAGE>   1
                       [Letterhead of AvSOLUTIONS, Inc.]

                                                                    Exhibit 23.4


December 16, 1998


America West Airlines, Inc.
51 West Third Street
Tempe, AZ  85281


Re:      America West Airlines, Inc.
         Pass Through Certificates, Series 1998-1


Ladies and Gentlemen:

         We consent to the reference to our name in the text under the headings
"Risk Factors - Risk Factors Relating to the Certificates and the Exchange Offer
- - Possible Effects if Aircraft Appraisals do not Correspond to the Realizable
Value of Aircraft," "Description of the Aircraft and the Appraisals - The
Appraisals", "Experts" and "Appendix II - Appraisal Letters" in the Registration
Statement on Form S-4 being filed with the Securities and Exchange Commission.
We also consent to the inclusion in the Registration Statement of the report
prepared by us with respect to the Aircraft referred to therein.


Sincerely,

/s/ Bryant E. Lynch
- ------------------------------
Bryant E. Lynch
Manager, Commercial Appraisals


<PAGE>   1
                      [Letterhead of BK Associates, Inc.]

                                                                    Exhibit 23.5

December 16, 1998


America West Airlines, Inc.
51 West Third Street
Tempe, AZ  85281


Re:      America West Airlines, Inc.
         Pass Through Certificates, Series 1998-1


Ladies & Gentlemen:

         We consent to the reference to our name in the text under the headings
"Risk Factors - Risk Factors Relating to the Certificates and the Exchange Offer
- - Possible Effects if Aircraft Appraisals do not Correspond to the Realizable
Value of Aircraft," "Description of the Aircraft and the Appraisals - The
Appraisals", "Experts" and "Appendix II - Appraisal Letters" in the Registration
Statement on Form S-4 being filed with the Securities and Exchange Commission.
We also consent to the inclusion in the Registration Statement of the report
prepared by us with respect to the Aircraft referred to therein.


                                        Sincerely,


                                        BK ASSOCIATES, INC.
                                        /s/ John F. Keitz
                                        John F. Keitz
                                        President
                                        ISTAT Senior Certified Appraiser

JFK/kf

<PAGE>   1
                                                                    EXHIBIT 25.1




                                                                Registration No.



                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM T-1

         STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939
                  OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE

   CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO
                               SECTION 305(b)(2)

                            WILMINGTON TRUST COMPANY
               (Exact name of trustee as specified in its charter)


        Delaware                                        51-0055023
(State of incorporation)                    (I.R.S. employer identification no.)

                               Rodney Square North
                            1100 North Market Street
                           Wilmington, Delaware 19890
                    (Address of principal executive offices)

                               Cynthia L. Corliss
                        Vice President and Trust Counsel
                            Wilmington Trust Company
                               Rodney Square North
                           Wilmington, Delaware 19890
                                 (302) 651-8516
            (Name, address and telephone number of agent for service)

                           AMERICA WEST AIRLINES, INC.

               (Exact name of obligor as specified in its charter)

        Delaware                                        86-0418245
(State of incorporation)                    (I.R.S. employer identification no.)

4000 E. Sky Harbor Boulevard
     Phoenix, Arizona                                   85034-3899
(Address of principal executive offices)                (Zip Code)


                    Pass Through Certificates, Series 1998-1A
<PAGE>   2
                                                                          Page 2


                       (Title of the indenture securities)
<PAGE>   3
                                                                          Page 3


ITEM 1.     GENERAL INFORMATION.

                    Furnish the following information as to the trustee:

            (a)     Name and address of each examining or supervising authority
                    to which it is subject.

                    Federal Deposit Insurance Co.        State Bank Commissioner
                    Five Penn Center                        Dover, Delaware
                    Suite #2901
                    Philadelphia, PA

            (b)     Whether it is authorized to exercise corporate trust powers.

                    The trustee is authorized to exercise corporate trust
                    powers.

ITEM 2.     AFFILIATIONS WITH THE OBLIGOR.

                    If the obligor is an affiliate of the trustee, describe each
            affiliation:

                    Based upon an examination of the books and records of the
            trustee and upon information furnished by the obligor, the obligor
            is not an affiliate of the trustee.

ITEM 3.  LIST OF EXHIBITS.

                 List below all exhibits filed as part of this Statement of
Eligibility and Qualification.

            A.      Copy of the Charter of Wilmington Trust Company, which
                    includes the certificate of authority of Wilmington Trust
                    Company to commence business and the authorization of
                    Wilmington Trust Company to exercise corporate trust powers.

            B.      Copy of By-Laws of Wilmington Trust Company.

            C.      Consent of Wilmington Trust Company required by Section
                    321(b) of Trust Indenture Act.

            D.      Copy of most recent Report of Condition of Wilmington Trust
                    Company.

            Pursuant to the requirements of the Trust Indenture Act of 1939, as
amended, the trustee, Wilmington Trust Company, a corporation organized and
existing under the laws of Delaware, has duly caused this Statement of
Eligibility to be signed on its behalf by the undersigned, thereunto duly
authorized, all in the City of Wilmington and State of Delaware on the 10th day
of December, 1998.


                                             WILMINGTON TRUST COMPANY
[SEAL]

Attest:/s/ Christopher L. Kaiser             By:/s/ James P. Lawler            
       -------------------------                -------------------
       Assistant Secretary                   Name:  James P. Lawler
                                             Title:  Vice President
<PAGE>   4
                                                                          Page 4


                                    EXHIBIT A

                                 AMENDED CHARTER

                            WILMINGTON TRUST COMPANY

                              WILMINGTON, DELAWARE

                           AS EXISTING ON MAY 9, 1987
<PAGE>   5
                                                                          Page 5


                                 AMENDED CHARTER

                                       OR

                              ACT OF INCORPORATION

                                       OF

                            WILMINGTON TRUST COMPANY

            WILMINGTON TRUST COMPANY, originally incorporated by an Act of the
General Assembly of the State of Delaware, entitled "An Act to Incorporate the
Delaware Guarantee and Trust Company", approved March 2, A.D. 1901, and the name
of which company was changed to "WILMINGTON TRUST COMPANY" by an amendment filed
in the Office of the Secretary of State on March 18, A.D. 1903, and the Charter
or Act of Incorporation of which company has been from time to time amended and
changed by merger agreements pursuant to the corporation law for state banks and
trust companies of the State of Delaware, does hereby alter and amend its
Charter or Act of Incorporation so that the same as so altered and amended shall
in its entirety read as follows:

            FIRST: - The name of this corporation is WILMINGTON TRUST COMPANY.

            SECOND: - The location of its principal office in the State of
            Delaware is at Rodney Square North, in the City of Wilmington,
            County of New Castle; the name of its resident agent is WILMINGTON
            TRUST COMPANY whose address is Rodney Square North, in said City. In
            addition to such principal office, the said corporation maintains
            and operates branch offices in the City of Newark, New Castle
            County, Delaware, the Town of Newport, New Castle County, Delaware,
            at Claymont, New Castle County, Delaware, at Greenville, New Castle
            County Delaware, and at Milford Cross Roads, New Castle County,
            Delaware, and shall be empowered to open, maintain and operate
            branch offices at Ninth and Shipley Streets, 418 Delaware Avenue,
            2120 Market Street, and 3605 Market Street, all in the City of
            Wilmington, New Castle County, Delaware, and such other branch
            offices or places of business as may be authorized from time to time
            by the agency or agencies of the government of the State of Delaware
            empowered to confer such authority.

            THIRD: - (a) The nature of the business and the objects and purposes
            proposed to be transacted, promoted or carried on by this
            Corporation are to do any or all of the things herein mentioned as
            fully and to the same extent as natural persons might or could do
            and in any part of the world, viz.:

                    (1) To sue and be sued, complain and defend in any Court of
                    law or equity and to make and use a common seal, and alter
                    the seal at pleasure, to hold, purchase, convey, mortgage or
                    otherwise deal in real 
<PAGE>   6
                                                                          Page 6


                    and personal estate and property, and to appoint such
                    officers and agents as the business of the Corporation shall
                    require, to make by-laws not inconsistent with the
                    Constitution or laws of the United States or of this State,
                    to discount bills, notes or other evidences of debt, to
                    receive deposits of money, or securities for money, to buy
                    gold and silver bullion and foreign coins, to buy and sell
                    bills of exchange, and generally to use, exercise and enjoy
                    all the powers, rights, privileges and franchises incident
                    to a corporation which are proper or necessary for the
                    transaction of the business of the Corporation hereby
                    created.

                    (2) To insure titles to real and personal property, or any
                    estate or interests therein, and to guarantee the holder of
                    such property, real or personal, against any claim or
                    claims, adverse to his interest therein, and to prepare and
                    give certificates of title for any lands or premises in the
                    State of Delaware, or elsewhere.

                    (3) To act as factor, agent, broker or attorney in the
                    receipt, collection, custody, investment and management of
                    funds, and the purchase, sale, management and disposal of
                    property of all descriptions, and to prepare and execute all
                    papers which may be necessary or proper in such business.

                    (4) To prepare and draw agreements, contracts, deeds,
                    leases, conveyances, mortgages, bonds and legal papers of
                    every description, and to carry on the business of
                    conveyancing in all its branches.

                    (5) To receive upon deposit for safekeeping money, jewelry,
                    plate, deeds, bonds and any and all other personal property
                    of every sort and kind, from executors, administrators,
                    guardians, public officers, courts, receivers, assignees,
                    trustees, and from all fiduciaries, and from all other
                    persons and individuals, and from all corporations whether
                    state, municipal, corporate or private, and to rent boxes,
                    safes, vaults and other receptacles for such property.

                    (6) To act as agent or otherwise for the purpose of
                    registering, issuing, certificating, countersigning,
                    transferring or underwriting the stock, bonds or other
                    obligations of any corporation, association, state or
                    municipality, and may receive and manage any sinking fund
                    therefor on such terms as may be agreed upon between the two
                    parties, and in like manner may act as Treasurer of any
                    corporation or municipality.

                    (7) To act as Trustee under any deed of trust, mortgage,
                    bond or other instrument issued by any state, municipality,
                    body politic, corporation, association or person, either
                    alone or in conjunction with any other person or persons,
                    corporation or corporations.
<PAGE>   7
                                                                          Page 7


                    (8) To guarantee the validity, performance or effect of any
                    contract or agreement, and the fidelity of persons holding
                    places of responsibility or trust; to become surety for any
                    person, or persons, for the faithful performance of any
                    trust, office, duty, contract or agreement, either by itself
                    or in conjunction with any other person, or persons,
                    corporation, or corporations, or in like manner become
                    surety upon any bond, recognizance, obligation, judgment,
                    suit, order, or decree to be entered in any court of record
                    within the State of Delaware or elsewhere, or which may now
                    or hereafter be required by any law, judge, officer or court
                    in the State of Delaware or elsewhere.

                    (9) To act by any and every method of appointment as
                    trustee, trustee in bankruptcy, receiver, assignee, assignee
                    in bankruptcy, executor, administrator, guardian, bailee, or
                    in any other trust capacity in the receiving, holding,
                    managing, and disposing of any and all estates and property,
                    real, personal or mixed, and to be appointed as such
                    trustee, trustee in bankruptcy, receiver, assignee, assignee
                    in bankruptcy, executor, administrator, guardian or bailee
                    by any persons, corporations, court, officer, or authority,
                    in the State of Delaware or elsewhere; and whenever this
                    Corporation is so appointed by any person, corporation,
                    court, officer or authority such trustee, trustee in
                    bankruptcy, receiver, assignee, assignee in bankruptcy,
                    executor, administrator, guardian, bailee, or in any other
                    trust capacity, it shall not be required to give bond with
                    surety, but its capital stock shall be taken and held as
                    security for the performance of the duties devolving upon it
                    by such appointment.

                    (10) And for its care, management and trouble, and the
                    exercise of any of its powers hereby given, or for the
                    performance of any of the duties which it may undertake or
                    be called upon to perform, or for the assumption of any
                    responsibility the said Corporation may be entitled to
                    receive a proper compensation.

                    (11) To purchase, receive, hold and own bonds, mortgages,
                    debentures, shares of capital stock, and other securities,
                    obligations, contracts and evidences of indebtedness, of any
                    private, public or municipal corporation within and without
                    the State of Delaware, or of the Government of the United
                    States, or of any state, territory, colony, or possession
                    thereof, or of any foreign government or country; to
                    receive, collect, receipt for, and dispose of interest,
                    dividends and income upon and from any of the bonds,
                    mortgages, debentures, notes, shares of capital stock,
                    securities, obligations, contracts, evidences of
                    indebtedness and other property held and owned by it, and to
                    exercise in respect of all such bonds, mortgages,
                    debentures, notes, shares of capital stock, securities,
                    obligations, contracts, evidences of indebtedness and other
                    property, any and all the rights, powers and privileges of
                    individual owners thereof, including the right to vote
                    thereon; 
<PAGE>   8
                                                                          Page 8


                    to invest and deal in and with any of the moneys of the
                    Corporation upon such securities and in such manner as it
                    may think fit and proper, and from time to time to vary or
                    realize such investments; to issue bonds and secure the same
                    by pledges or deeds of trust or mortgages of or upon the
                    whole or any part of the property held or owned by the
                    Corporation, and to sell and pledge such bonds, as and when
                    the Board of Directors shall determine, and in the promotion
                    of its said corporate business of investment and to the
                    extent authorized by law, to lease, purchase, hold, sell,
                    assign, transfer, pledge, mortgage and convey real and
                    personal property of any name and nature and any estate or
                    interest therein.

            (b) In furtherance of, and not in limitation, of the powers
            conferred by the laws of the State of Delaware, it is hereby
            expressly provided that the said Corporation shall also have the
            following powers:

                    (1) To do any or all of the things herein set forth, to the
                    same extent as natural persons might or could do, and in any
                    part of the world.

                    (2) To acquire the good will, rights, property and
                    franchises and to undertake the whole or any part of the
                    assets and liabilities of any person, firm, association or
                    corporation, and to pay for the same in cash, stock of this
                    Corporation, bonds or otherwise; to hold or in any manner to
                    dispose of the whole or any part of the property so
                    purchased; to conduct in any lawful manner the whole or any
                    part of any business so acquired, and to exercise all the
                    powers necessary or convenient in and about the conduct and
                    management of such business.

                    (3) To take, hold, own, deal in, mortgage or otherwise lien,
                    and to lease, sell, exchange, transfer, or in any manner
                    whatever dispose of property, real, personal or mixed,
                    wherever situated.

                    (4) To enter into, make, perform and carry out contracts of
                    every kind with any person, firm, association or
                    corporation, and, without limit as to amount, to draw, make,
                    accept, endorse, discount, execute and issue promissory
                    notes, drafts, bills of exchange, warrants, bonds,
                    debentures, and other negotiable or transferable
                    instruments.

                    (5) To have one or more offices, to carry on all or any of
                    its operations and businesses, without restriction to the
                    same extent as natural persons might or could do, to
                    purchase or otherwise acquire, to hold, own, to mortgage,
                    sell, convey or otherwise dispose of, real and personal
                    property, of every class and description, in any State,
                    District, Territory or Colony of the United States, and in
                    any foreign country or place.

                    (6) It is the intention that the objects, purposes and
                    powers specified and clauses contained in this paragraph
                    shall (except where otherwise 
<PAGE>   9
                                                                          Page 9


                    expressed in said paragraph) be nowise limited or restricted
                    by reference to or inference from the terms of any other
                    clause of this or any other paragraph in this charter, but
                    that the objects, purposes and powers specified in each of
                    the clauses of this paragraph shall be regarded as
                    independent objects, purposes and powers.

            FOURTH: - (a) The total number of shares of all classes of stock
            which the Corporation shall have authority to issue is forty-one
            million (41,000,000) shares, consisting of:

                    (1) One million (1,000,000) shares of Preferred stock, par
                    value $10.00 per share (hereinafter referred to as
                    "Preferred Stock"); and

                    (2) Forty million (40,000,000) shares of Common Stock, par
                    value $1.00 per share (hereinafter referred to as "Common
                    Stock").

            (b) Shares of Preferred Stock may be issued from time to time in one
            or more series as may from time to time be determined by the Board
            of Directors each of said series to be distinctly designated. All
            shares of any one series of Preferred Stock shall be alike in every
            particular, except that there may be different dates from which
            dividends, if any, thereon shall be cumulative, if made cumulative.
            The voting powers and the preferences and relative, participating,
            optional and other special rights of each such series, and the
            qualifications, limitations or restrictions thereof, if any, may
            differ from those of any and all other series at any time
            outstanding; and, subject to the provisions of subparagraph 1 of
            Paragraph (c) of this Article FOURTH, the Board of Directors of the
            Corporation is hereby expressly granted authority to fix by
            resolution or resolutions adopted prior to the issuance of any
            shares of a particular series of Preferred Stock, the voting powers
            and the designations, preferences and relative, optional and other
            special rights, and the qualifications, limitations and restrictions
            of such series, including, but without limiting the generality of
            the foregoing, the following:

                    (1) The distinctive designation of, and the number of shares
                    of Preferred Stock which shall constitute such series, which
                    number may be increased (except where otherwise provided by
                    the Board of Directors) or decreased (but not below the
                    number of shares thereof then outstanding) from time to time
                    by like action of the Board of Directors;

                    (2) The rate and times at which, and the terms and
                    conditions on which, dividends, if any, on Preferred Stock
                    of such series shall be paid, the extent of the preference
                    or relation, if any, of such dividends to the dividends
                    payable on any other class or classes, or series of the same
                    or other class of stock and whether such dividends shall be
                    cumulative or non-cumulative;
<PAGE>   10
                                                                         Page 10


                    (3) The right, if any, of the holders of Preferred Stock of
                    such series to convert the same into or exchange the same
                    for, shares of any other class or classes or of any series
                    of the same or any other class or classes of stock of the
                    Corporation and the terms and conditions of such conversion
                    or exchange;

                    (4) Whether or not Preferred Stock of such series shall be
                    subject to redemption, and the redemption price or prices
                    and the time or times at which, and the terms and conditions
                    on which, Preferred Stock of such series may be redeemed.

                    (5) The rights, if any, of the holders of Preferred Stock of
                    such series upon the voluntary or involuntary liquidation,
                    merger, consolidation, distribution or sale of assets,
                    dissolution or winding-up, of the Corporation.

                    (6) The terms of the sinking fund or redemption or purchase
                    account, if any, to be provided for the Preferred Stock of
                    such series; and

                    (7) The voting powers, if any, of the holders of such series
                    of Preferred Stock which may, without limiting the
                    generality of the foregoing include the right, voting as a
                    series or by itself or together with other series of
                    Preferred Stock or all series of Preferred Stock as a class,
                    to elect one or more directors of the Corporation if there
                    shall have been a default in the payment of dividends on any
                    one or more series of Preferred Stock or under such
                    circumstances and on such conditions as the Board of
                    Directors may determine.

            (c) (1) After the requirements with respect to preferential
            dividends on the Preferred Stock (fixed in accordance with the
            provisions of section (b) of this Article FOURTH), if any, shall
            have been met and after the Corporation shall have complied with all
            the requirements, if any, with respect to the setting aside of sums
            as sinking funds or redemption or purchase accounts (fixed in
            accordance with the provisions of section (b) of this Article
            FOURTH), and subject further to any conditions which may be fixed in
            accordance with the provisions of section (b) of this Article
            FOURTH, then and not otherwise the holders of Common Stock shall be
            entitled to receive such dividends as may be declared from time to
            time by the Board of Directors.

                    (2) After distribution in full of the preferential amount,
                    if any, (fixed in accordance with the provisions of section
                    (b) of this Article FOURTH), to be distributed to the
                    holders of Preferred Stock in the event of voluntary or
                    involuntary liquidation, distribution or sale of assets,
                    dissolution or winding-up, of the Corporation, the holders
                    of the Common Stock shall be entitled to receive all of the
                    remaining assets of the Corporation, tangible and
                    intangible, of whatever kind available for distribution to
<PAGE>   11
                                                                         Page 11


                    stockholders ratably in proportion to the number of shares
                    of Common Stock held by them respectively.

                    (3) Except as may otherwise be required by law or by the
                    provisions of such resolution or resolutions as may be
                    adopted by the Board of Directors pursuant to section (b) of
                    this Article FOURTH, each holder of Common Stock shall have
                    one vote in respect of each share of Common Stock held on
                    all matters voted upon by the stockholders.

            (d) No holder of any of the shares of any class or series of stock
            or of options, warrants or other rights to purchase shares of any
            class or series of stock or of other securities of the Corporation
            shall have any preemptive right to purchase or subscribe for any
            unissued stock of any class or series or any additional shares of
            any class or series to be issued by reason of any increase of the
            authorized capital stock of the Corporation of any class or series,
            or bonds, certificates of indebtedness, debentures or other
            securities convertible into or exchangeable for stock of the
            Corporation of any class or series, or carrying any right to
            purchase stock of any class or series, but any such unissued stock,
            additional authorized issue of shares of any class or series of
            stock or securities convertible into or exchangeable for stock, or
            carrying any right to purchase stock, may be issued and disposed of
            pursuant to resolution of the Board of Directors to such persons,
            firms, corporations or associations, whether such holders or others,
            and upon such terms as may be deemed advisable by the Board of
            Directors in the exercise of its sole discretion.

            (e) The relative powers, preferences and rights of each series of
            Preferred Stock in relation to the relative powers, preferences and
            rights of each other series of Preferred Stock shall, in each case,
            be as fixed from time to time by the Board of Directors in the
            resolution or resolutions adopted pursuant to authority granted in
            section (b) of this Article FOURTH and the consent, by class or
            series vote or otherwise, of the holders of such of the series of
            Preferred Stock as are from time to time outstanding shall not be
            required for the issuance by the Board of Directors of any other
            series of Preferred Stock whether or not the powers, preferences and
            rights of such other series shall be fixed by the Board of Directors
            as senior to, or on a parity with, the powers, preferences and
            rights of such outstanding series, or any of them; provided,
            however, that the Board of Directors may provide in the resolution
            or resolutions as to any series of Preferred Stock adopted pursuant
            to section (b) of this Article FOURTH that the consent of the
            holders of a majority (or such greater proportion as shall be
            therein fixed) of the outstanding shares of such series voting
            thereon shall be required for the issuance of any or all other
            series of Preferred Stock.

            (f) Subject to the provisions of section (e), shares of any series
            of Preferred Stock may be issued from time to time as the Board of
            Directors of the Corporation shall determine and on such terms and
            for such consideration as 
<PAGE>   12
                                                                         Page 12


            shall be fixed by the Board of Directors.

            (g) Shares of Common Stock may be issued from time to time as the
            Board of Directors of the Corporation shall determine and on such
            terms and for such consideration as shall be fixed by the Board of
            Directors.

            (h) The authorized amount of shares of Common Stock and of Preferred
            Stock may, without a class or series vote, be increased or decreased
            from time to time by the affirmative vote of the holders of a
            majority of the stock of the Corporation entitled to vote thereon.

            FIFTH: - (a) The business and affairs of the Corporation shall be
            conducted and managed by a Board of Directors. The number of
            directors constituting the entire Board shall be not less than five
            nor more than twenty-five as fixed from time to time by vote of a
            majority of the whole Board, provided, however, that the number of
            directors shall not be reduced so as to shorten the term of any
            director at the time in office, and provided further, that the
            number of directors constituting the whole Board shall be
            twenty-four until otherwise fixed by a majority of the whole Board.

            (b) The Board of Directors shall be divided into three classes, as
            nearly equal in number as the then total number of directors
            constituting the whole Board permits, with the term of office of one
            class expiring each year. At the annual meeting of stockholders in
            1982, directors of the first class shall be elected to hold office
            for a term expiring at the next succeeding annual meeting, directors
            of the second class shall be elected to hold office for a term
            expiring at the second succeeding annual meeting and directors of
            the third class shall be elected to hold office for a term expiring
            at the third succeeding annual meeting. Any vacancies in the Board
            of Directors for any reason, and any newly created directorships
            resulting from any increase in the directors, may be filled by the
            Board of Directors, acting by a majority of the directors then in
            office, although less than a quorum, and any directors so chosen
            shall hold office until the next annual election of directors. At
            such election, the stockholders shall elect a successor to such
            director to hold office until the next election of the class for
            which such director shall have been chosen and until his successor
            shall be elected and qualified. No decrease in the number of
            directors shall shorten the term of any incumbent director.

            (c) Notwithstanding any other provisions of this Charter or Act of
            Incorporation or the By-Laws of the Corporation (and notwithstanding
            the fact that some lesser percentage may be specified by law, this
            Charter or Act of Incorporation or the ByLaws of the Corporation),
            any director or the entire Board of Directors of the Corporation may
            be removed at any time without cause, but only by the affirmative
            vote of the holders of two-thirds or more of the outstanding shares
            of capital stock of the Corporation entitled to vote generally in
            the election of directors (considered for this purpose as one class)
            cast at a 
<PAGE>   13
                                                                         Page 13


            meeting of the stockholders called for that purpose.

            (d) Nominations for the election of directors may be made by the
            Board of Directors or by any stockholder entitled to vote for the
            election of directors. Such nominations shall be made by notice in
            writing, delivered or mailed by first class United States mail,
            postage prepaid, to the Secretary of the Corporation not less than
            14 days nor more than 50 days prior to any meeting of the
            stockholders called for the election of directors; provided,
            however, that if less than 21 days' notice of the meeting is given
            to stockholders, such written notice shall be delivered or mailed,
            as prescribed, to the Secretary of the Corporation not later than
            the close of the seventh day following the day on which notice of
            the meeting was mailed to stockholders. Notice of nominations which
            are proposed by the Board of Directors shall be given by the
            Chairman on behalf of the Board.

            (e) Each notice under subsection (d) shall set forth (i) the name,
            age, business address and, if known, residence address of each
            nominee proposed in such notice, (ii) the principal occupation or
            employment of such nominee and (iii) the number of shares of stock
            of the Corporation which are beneficially owned by each such
            nominee.

            (f) The Chairman of the meeting may, if the facts warrant, determine
            and declare to the meeting that a nomination was not made in
            accordance with the foregoing procedure, and if he should so
            determine, he shall so declare to the meeting and the defective
            nomination shall be disregarded.

            (g) No action required to be taken or which may be taken at any
            annual or special meeting of stockholders of the Corporation may be
            taken without a meeting, and the power of stockholders to consent in
            writing, without a meeting, to the taking of any action is
            specifically denied.

            SIXTH: - The Directors shall choose such officers, agent and
            servants as may be provided in the By-Laws as they may from time to
            time find necessary or proper.

            SEVENTH: - The Corporation hereby created is hereby given the same
            powers, rights and privileges as may be conferred upon corporations
            organized under the Act entitled "An Act Providing a General
            Corporation Law", approved March 10, 1899, as from time to time
            amended.

            EIGHTH: - This Act shall be deemed and taken to be a private Act.

            NINTH: - This Corporation is to have perpetual existence.

            TENTH: - The Board of Directors, by resolution passed by a majority
            of the whole Board, may designate any of their number to constitute
            an Executive 
<PAGE>   14
                                                                         Page 14


            Committee, which Committee, to the extent provided in said
            resolution, or in the By-Laws of the Company, shall have and may
            exercise all of the powers of the Board of Directors in the
            management of the business and affairs of the Corporation, and shall
            have power to authorize the seal of the Corporation to be affixed to
            all papers which may require it.

            ELEVENTH: - The private property of the stockholders shall not be
            liable for the payment of corporate debts to any extent whatever.

            TWELFTH: - The Corporation may transact business in any part of the
            world.

            THIRTEENTH: - The Board of Directors of the Corporation is expressly
            authorized to make, alter or repeal the By-Laws of the Corporation
            by a vote of the majority of the entire Board. The stockholders may
            make, alter or repeal any By-Law whether or not adopted by them,
            provided however, that any such additional By-Laws, alterations or
            repeal may be adopted only by the affirmative vote of the holders of
            two-thirds or more of the outstanding shares of capital stock of the
            Corporation entitled to vote generally in the election of directors
            (considered for this purpose as one class).

            FOURTEENTH: - Meetings of the Directors may be held outside
            of the State of Delaware at such places as may be from time to time
            designated by the Board, and the Directors may keep the books of the
            Company outside of the State of Delaware at such places as may be
            from time to time designated by them.

            FIFTEENTH: - (a) In addition to any affirmative vote required by
            law, and except as otherwise expressly provided in sections (b) and
            (c) of this Article FIFTEENTH:

                    (A) any merger or consolidation of the Corporation or any
                    Subsidiary (as hereinafter defined) with or into (i) any
                    Interested Stockholder (as hereinafter defined) or (ii) any
                    other corporation (whether or not itself an Interested
                    Stockholder), which, after such merger or consolidation,
                    would be an Affiliate (as hereinafter defined) of an
                    Interested Stockholder, or

                    (B) any sale, lease, exchange, mortgage, pledge, transfer or
                    other disposition (in one transaction or a series of related
                    transactions) to or with any Interested Stockholder or any
                    Affiliate of any Interested Stockholder of any assets of the
                    Corporation or any Subsidiary having an aggregate fair
                    market value of $1,000,000 or more, or

                    (C) the issuance or transfer by the Corporation or any
                    Subsidiary (in one transaction or a series of related
                    transactions) of any securities of the Corporation or any
                    Subsidiary to any Interested Stockholder or any Affiliate of
                    any Interested Stockholder in exchange for cash, securities
                    or 
<PAGE>   15
                                                                         Page 15


                    other property (or a combination thereof) having an
                    aggregate fair market value of $1,000,000 or more, or

                    (D) the adoption of any plan or proposal for the liquidation
                    or dissolution of the Corporation, or

                    (E) any reclassification of securities (including any
                    reverse stock split), or recapitalization of the
                    Corporation, or any merger or consolidation of the
                    Corporation with any of its Subsidiaries or any similar
                    transaction (whether or not with or into or otherwise
                    involving an Interested Stockholder) which has the effect,
                    directly or indirectly, of increasing the proportionate
                    share of the outstanding shares of any class of equity or
                    convertible securities of the Corporation or any Subsidiary
                    which is directly or indirectly owned by any Interested
                    Stockholder, or any Affiliate of any Interested Stockholder,

shall require the affirmative vote of the holders of at least two-thirds of the
outstanding shares of capital stock of the Corporation entitled to vote
generally in the election of directors, considered for the purpose of this
Article FIFTEENTH as one class ("Voting Shares"). Such affirmative vote shall be
required notwithstanding the fact that no vote may be required, or that some
lesser percentage may be specified, by law or in any agreement with any national
securities exchange or otherwise.

                      (2) The term "business combination" as used in this
                      Article FIFTEENTH shall mean any transaction which is
                      referred to any one or more of clauses (A) through (E) of
                      paragraph 1 of the section (a).

                    (b) The provisions of section (a) of this Article FIFTEENTH
                    shall not be applicable to any particular business
                    combination and such business combination shall require only
                    such affirmative vote as is required by law and any other
                    provisions of the Charter or Act of Incorporation of By-Laws
                    if such business combination has been approved by a majority
                    of the whole Board.

                    (c) For the purposes of this Article FIFTEENTH:

            (1) A "person" shall mean any individual firm, corporation or other
            entity.

            (2) "Interested Stockholder" shall mean, in respect of any business
            combination, any person (other than the Corporation or any
            Subsidiary) who or which as of the record date for the determination
            of stockholders entitled to notice of and to vote on such business
            combination, or immediately prior to the consummation of any such
            transaction:

                    (A) is the beneficial owner, directly or indirectly, of more
                    than 10% of the Voting Shares, or
<PAGE>   16
                                                                         Page 16


                    (B) is an Affiliate of the Corporation and at any time
                    within two years prior thereto was the beneficial owner,
                    directly or indirectly, of not less than 10% of the then
                    outstanding voting Shares, or

                    (C) is an assignee of or has otherwise succeeded in any
                    share of capital stock of the Corporation which were at any
                    time within two years prior thereto beneficially owned by
                    any Interested Stockholder, and such assignment or
                    succession shall have occurred in the course of a
                    transaction or series of transactions not involving a public
                    offering within the meaning of the Securities Act of 1933.

            (3) A person shall be the "beneficial owner" of any Voting Shares:

                    (A) which such person or any of its Affiliates and
                    Associates (as hereafter defined) beneficially own, directly
                    or indirectly, or

                    (B) which such person or any of its Affiliates or Associates
                    has (i) the right to acquire (whether such right is
                    exercisable immediately or only after the passage of time),
                    pursuant to any agreement, arrangement or understanding or
                    upon the exercise of conversion rights, exchange rights,
                    warrants or options, or otherwise, or (ii) the right to vote
                    pursuant to any agreement, arrangement or understanding, or

                    (C) which are beneficially owned, directly or indirectly, by
                    any other person with which such first mentioned person or
                    any of its Affiliates or Associates has any agreement,
                    arrangement or understanding for the purpose of acquiring,
                    holding, voting or disposing of any shares of capital stock
                    of the Corporation.

            (4) The outstanding Voting Shares shall include shares deemed owned
            through application of paragraph (3) above but shall not include any
            other Voting Shares which may be issuable pursuant to any agreement,
            or upon exercise of conversion rights, warrants or options or
            otherwise.

            (5) "Affiliate" and "Associate" shall have the respective meanings
            given those terms in Rule 12b-2 of the General Rules and Regulations
            under the Securities Exchange Act of 1934, as in effect on December
            31, 1981.

            (6) "Subsidiary" shall mean any corporation of which a majority of
            any class of equity security (as defined in Rule 3a11-1 of the
            General Rules and Regulations under the Securities Exchange Act of
            1934, as in effect in December 31, 1981) is owned, directly or
            indirectly, by the Corporation; provided, however, that for the
            purposes of the definition of Investment Stockholder set forth in
            paragraph (2) of this section (c), the term "Subsidiary" shall mean
            only a corporation of which a majority of each class of equity
<PAGE>   17
                                                                         Page 17


            security is owned, directly or indirectly, by the Corporation.

                    (d) majority of the directors shall have the power and duty
                    to determine for the purposes of this Article FIFTEENTH on
                    the basis of information known to them, (1) the number of
                    Voting Shares beneficially owned by any person (2) whether a
                    person is an Affiliate or Associate of another, (3) whether
                    a person has an agreement, arrangement or understanding with
                    another as to the matters referred to in paragraph (3) of
                    section (c), or (4) whether the assets subject to any
                    business combination or the consideration received for the
                    issuance or transfer of securities by the Corporation, or
                    any Subsidiary has an aggregate fair market value of
                    $1,000,000 or more.

                    (e) Nothing contained in this Article FIFTEENTH shall be
                    construed to relieve any Interested Stockholder from any
                    fiduciary obligation imposed by law.

            SIXTEENTH: Notwithstanding any other provision of this Charter or
            Act of Incorporation or the By-Laws of the Corporation (and in
            addition to any other vote that may be required by law, this Charter
            or Act of Incorporation by the By-Laws), the affirmative vote of the
            holders of at least two-thirds of the outstanding shares of the
            capital stock of the Corporation entitled to vote generally in the
            election of directors (considered for this purpose as one class)
            shall be required to amend, alter or repeal any provision of
            Articles FIFTH, THIRTEENTH, FIFTEENTH or SIXTEENTH of this Charter
            or Act of Incorporation.

            SEVENTEENTH: (a) a Director of this Corporation shall not be liable
            to the Corporation or its stockholders for monetary damages for
            breach of fiduciary duty as a Director, except to the extent such
            exemption from liability or limitation thereof is not permitted
            under the Delaware General Corporation Laws as the same exists or
            may hereafter be amended.

                    (b) Any repeal or modification of the foregoing paragraph
                    shall not adversely affect any right or protection of a
                    Director of the Corporation existing hereunder with respect
                    to any act or omission occurring prior to the time of such
                    repeal or modification."
<PAGE>   18
                                                                         Page 18


                                    EXHIBIT B

                                     BY-LAWS


                            WILMINGTON TRUST COMPANY

                              WILMINGTON, DELAWARE

                         AS EXISTING ON JANUARY 16, 1997
<PAGE>   19
                                                                         Page 19


                       BY-LAWS OF WILMINGTON TRUST COMPANY


                                    ARTICLE I
                             STOCKHOLDERS' MEETINGS

            Section 1. The Annual Meeting of Stockholders shall be held on the
third Thursday in April each year at the principal office at the Company or at
such other date, time, or place as may be designated by resolution by the Board
of Directors.

            Section 2. Special meetings of all stockholders may be called at any
time by the Board of Directors, the Chairman of the Board or the President.

            Section 3. Notice of all meetings of the stockholders shall be given
by mailing to each stockholder at least ten (10) days before said meeting, at
his last known address, a written or printed notice fixing the time and place of
such meeting.

            Section 4. A majority in the amount of the capital stock of the
Company issued and outstanding on the record date, as herein determined, shall
constitute a quorum at all meetings of stockholders for the transaction of any
business, but the holders of a small number of shares may adjourn, from time to
time, without further notice, until a quorum is secured. At each annual or
special meeting of stockholders, each stockholder shall be entitled to one vote,
either in person or by proxy, for each shares of stock registered in the
stockholder's name on the books of the Company on the record date for any such
meeting as determined herein.


                                   ARTICLE II
                                    DIRECTORS

            Section 1. The number and classification of the Board of Directors
shall be as set forth in the Charter of the Bank.

            Section 2. No person who has attained the age of seventy-two (72)
years shall be nominated for election to the Board of Directors of the Company,
provided, however, that this limitation shall not apply to any person who was
serving as director of the Company on September 16, 1971.

            Section 3. The class of Directors so elected shall hold office for
three years or until their successors are elected and qualified.

            Section 4. The affairs and business of the Company shall be managed
and conducted by the Board of Directors.

            Section 5. The Board of Directors shall meet at the principal office
of the Company or elsewhere in its discretion at such times to be determined by
a majority of 
<PAGE>   20
                                                                         Page 20


its members, or at the call of the Chairman of the Board of Directors or the
President.

            Section 6. Special meetings of the Board of Directors may be called
at any time by the Chairman of the Board of Directors or by the President, and
shall be called upon the written request of a majority of the directors.

            Section 7. A majority of the directors elected and qualified shall
be necessary to constitute a quorum for the transaction of business at any
meeting of the Board of Directors.

            Section 8. Written notice shall be sent by mail to each director of
any special meeting of the Board of Directors, and of any change in the time or
place of any regular meeting, stating the time and place of such meeting, which
shall be mailed not less than two days before the time of holding such meeting.

            Section 9. In the event of the death, resignation, removal,
inability to act, or disqualification of any director, the Board of Directors,
although less than a quorum, shall have the right to elect the successor who
shall hold office for the remainder of the full term of the class of directors
in which the vacancy occurred, and until such director's successor shall have
been duly elected and qualified.

            Section 10. The Board of Directors at its first meeting after its
election by the stockholders shall appoint an Executive Committee, a Trust
Committee, an Audit Committee and a Compensation Committee, and shall elect from
its own members a Chairman of the Board of Directors and a President who may be
the same person. The Board of Directors shall also elect at such meeting a
Secretary and a Treasurer, who may be the same person, may appoint at any time
such other committees and elect or appoint such other officers as it may deem
advisable. The Board of Directors may also elect at such meeting one or more
Associate Directors.

            Section 11. The Board of Directors may at any time remove, with or
without cause, any member of any Committee appointed by it or any associate
director or officer elected by it and may appoint or elect his successor.

            Section 12. The Board of Directors may designate an officer to be in
charge of such of the departments or division of the Company as it may deem
advisable.
<PAGE>   21
                                                                         Page 21


                                   ARTICLE III
                                   COMMITTEES

            Section 1.  Executive Committee

                        (A) The Executive Committee shall be composed of not
more than nine members who shall be selected by the Board of Directors from its
own members and who shall hold office during the pleasure of the Board.

                        (B) The Executive Committee shall have all the powers of
the Board of Directors when it is not in session to transact all business for
and in behalf of the Company that may be brought before it.

                        (C) The Executive Committee shall meet at the principal
office of the Company or elsewhere in its discretion at such times to be
determined by a majority of its members, or at the call of the Chairman of the
Executive Committee or at the call of the Chairman of the Board of Directors.
The majority of its members shall be necessary to constitute a quorum for the
transaction of business. Special meetings of the Executive Committee may be held
at any time when a quorum is present.

                        (D) Minutes of each meeting of the Executive Committee
shall be kept and submitted to the Board of Directors at its next meeting.

                        (E) The Executive Committee shall advise and superintend
all investments that may be made of the funds of the Company, and shall direct
the disposal of the same, in accordance with such rules and regulations as the
Board of Directors from time to time make.

                        (F) In the event of a state of disaster of sufficient
severity to prevent the conduct and management of the affairs and business of
the Company by its directors and officers as contemplated by these By-Laws any
two available members of the Executive Committee as constituted immediately
prior to such disaster shall constitute a quorum of that Committee for the full
conduct and management of the affairs and business of the Company in accordance
with the provisions of Article III of these By-Laws; and if less than three
members of the Trust Committee is constituted immediately prior to such disaster
shall be available for the transaction of its business, such Executive Committee
shall also be empowered to exercise all of the powers reserved to the Trust
Committee under Article III Section 2 hereof. In the event of the
unavailability, at such time, of a minimum of two members of such Executive
Committee, any three available directors shall constitute the Executive
Committee for the full conduct and management of the affairs and business of the
Company in accordance with the foregoing provisions of this Section. This By-Law
shall be subject to implementation by Resolutions of the Board of Directors
presently existing or hereafter passed from time to time for that purpose, and
any provisions of these By-Laws (other than this Section) and any resolutions
which are contrary to the provisions of this Section or to the provisions of any
such implementary Resolutions 
<PAGE>   22
                                                                         Page 22


shall be suspended during such a disaster period until it shall be determined by
any interim Executive Committee acting under this section that it shall be to
the advantage of the Company to resume the conduct and management of its affairs
and business under all of the other provisions of these By-Laws.

            Section 2.  Trust Committee

                        (A) The Trust Committee shall be composed of not more
than thirteen members who shall be selected by the Board of Directors, a
majority of whom shall be members of the Board of Directors and who shall hold
office during the pleasure of the Board.

                        (B) The Trust Committee shall have general supervision
over the Trust Department and the investment of trust funds, in all matters,
however, being subject to the approval of the Board of Directors.

                        (C) The Trust Committee shall meet at the principal
office of the Company or elsewhere in its discretion at such times to be
determined by a majority of its members or at the call of its chairman. A
majority of its members shall be necessary to constitute a quorum for the
transaction of business.

                        (D) Minutes of each meeting of the Trust Committee shall
be kept and promptly submitted to the Board of Directors.

                        (E) The Trust Committee shall have the power to appoint
Committees and/or designate officers or employees of the Company to whom
supervision over the investment of trust funds may be delegated when the Trust
Committee is not in session.

            Section 3.  Audit Committee

                        (A) The Audit Committee shall be composed of five
members who shall be selected by the Board of Directors from its own members,
none of whom shall be an officer of the Company, and shall hold office at the
pleasure of the Board.

                        (B) The Audit Committee shall have general supervision
over the Audit Division in all matters however subject to the approval of the
Board of Directors; it shall consider all matters brought to its attention by
the officer in charge of the Audit Division, review all reports of examination
of the Company made by any governmental agency or such independent auditor
employed for that purpose, and make such recommendations to the Board of
Directors with respect thereto or with respect to any other matters pertaining
to auditing the Company as it shall deem desirable.

                        (C) The Audit Committee shall meet whenever and wherever
the majority of its members shall deem it to be proper for the transaction of
its business, and a majority of its Committee shall constitute a quorum.
<PAGE>   23
                                                                         Page 23


            Section 4.  Compensation Committee

                        (A) The Compensation Committee shall be composed of not
more than five (5) members who shall be selected by the Board of Directors from
its own members who are not officers of the Company and who shall hold office
during the pleasure of the Board.

                        (B) The Compensation Committee shall in general advise
upon all matters of policy concerning the Company brought to its attention by
the management and from time to time review the management of the Company, major
organizational matters, including salaries and employee benefits and
specifically shall administer the Executive Incentive Compensation Plan.

                        (C) Meetings of the Compensation Committee may be called
at any time by the Chairman of the Compensation Committee, the Chairman of the
Board of Directors, or the President of the Company.

            Section 5.  Associate Directors

                        (A) Any person who has served as a director may be
elected by the Board of Directors as an associate director, to serve during the
pleasure of the Board.

                        (B) An associate director shall be entitled to attend
all directors meetings and participate in the discussion of all matters brought
to the Board, with the exception that he would have no right to vote. An
associate director will be eligible for appointment to Committees of the
Company, with the exception of the Executive Committee, Audit Committee and
Compensation Committee, which must be comprised solely of active directors.

            Section 6.  Absence or Disqualification of Any Member of a Committee

                        (A) In the absence or disqualification of any member of
any Committee created under Article III of the By-Laws of this Company, the
member or members thereof present at any meeting and not disqualified from
voting, whether or not he or they constitute a quorum, may unanimously appoint
another member of the Board of Directors to act at the meeting in the place of
any such absence or disqualified member.


                                   ARTICLE IV
                                    OFFICERS

            Section 1. The Chairman of the Board of Directors shall preside at
all meetings of the Board and shall have such further authority and powers and
shall perform such duties as the Board of Directors may from time to time confer
and direct. 
<PAGE>   24
                                                                         Page 24


He shall also exercise such powers and perform such duties as may from time to
time be agreed upon between himself and the President of the Company.

            Section 2. The Vice Chairman of the Board. The Vice Chairman of the
Board of Directors shall preside at all meetings of the Board of Directors at
which the Chairman of the Board shall not be present and shall have such further
authority and powers and shall perform such duties as the Board of Directors or
the Chairman of the Board may from time to time confer and direct.

            Section 3. The President shall have the powers and duties pertaining
to the office of the President conferred or imposed upon him by statute or
assigned to him by the Board of Directors in the absence of the Chairman of the
Board the President shall have the powers and duties of the Chairman of the
Board.

            Section 4. The Chairman of the Board of Directors or the President
as designated by the Board of Directors, shall carry into effect all legal
directions of the Executive Committee and of the Board of Directors, and shall
at all times exercise general supervision over the interest, affairs and
operations of the Company and perform all duties incident to his office.

            Section 5. There may be one or more Vice Presidents, however
denominated by the Board of Directors, who may at any time perform all the
duties of the Chairman of the Board of Directors and/or the President and such
other powers and duties as may from time to time be assigned to them by the
Board of Directors, the Executive Committee, the Chairman of the Board or the
President and by the officer in charge of the department or division to which
they are assigned.

            Section 6. The Secretary shall attend to the giving of notice of
meetings of the stockholders and the Board of Directors, as well as the
Committees thereof, to the keeping of accurate minutes of all such meetings and
to recording the same in the minute books of the Company. In addition to the
other notice requirements of these By-Laws and as may be practicable under the
circumstances, all such notices shall be in writing and mailed well in advance
of the scheduled date of any other meeting. He shall have custody of the
corporate seal and shall affix the same to any documents requiring such
corporate seal and to attest the same.

            Section 7. The Treasurer shall have general supervision over all
assets and liabilities of the Company. He shall be custodian of and responsible
for all monies, funds and valuables of the Company and for the keeping of proper
records of the evidence of property or indebtedness and of all the transactions
of the Company. He shall have general supervision of the expenditures of the
Company and shall report to the Board of Directors at each regular meeting of
the condition of the Company, and perform such other duties as may be assigned
to him from time to time by the Board of Directors of the Executive Committee.

            Section 8. There may be a Controller who shall exercise general
supervision 
<PAGE>   25
                                                                         Page 25


over the internal operations of the Company, including accounting, and shall
render to the Board of Directors at appropriate times a report relating to the
general condition and internal operations of the Company.

            There may be one or more subordinate accounting or controller
officers however denominated, who may perform the duties of the Controller and
such duties as may be prescribed by the Controller.

            Section 9. The officer designated by the Board of Directors to be in
charge of the Audit Division of the Company with such title as the Board of
Directors shall prescribe, shall report to and be directly responsible only to
the Board of Directors.

            There shall be an Auditor and there may be one or more Audit
Officers, however denominated, who may perform all the duties of the Auditor and
such duties as may be prescribed by the officer in charge of the Audit Division.

            Section 10. There may be one or more officers, subordinate in rank
to all Vice Presidents with such functional titles as shall be determined from
time to time by the Board of Directors, who shall ex officio hold the office
Assistant Secretary of this Company and who may perform such duties as may be
prescribed by the officer in charge of the department or division to whom they
are assigned.

            Section 11. The powers and duties of all other officers of the
Company shall be those usually pertaining to their respective offices, subject
to the direction of the Board of Directors, the Executive Committee, Chairman of
the Board of Directors or the President and the officer in charge of the
department or division to which they are assigned.


                                    ARTICLE V
                          STOCK AND STOCK CERTIFICATES

            Section 1. Shares of stock shall be transferrable on the books of
the Company and a transfer book shall be kept in which all transfers of stock
shall be recorded.

            Section 2. Certificate of stock shall bear the signature of the
President or any Vice President, however denominated by the Board of Directors
and countersigned by the Secretary or Treasurer or an Assistant Secretary, and
the seal of the corporation shall be engraved thereon. Each certificate shall
recite that the stock represented thereby is transferrable only upon the books
of the Company by the holder thereof or his attorney, upon surrender of the
certificate properly endorsed. Any certificate of stock surrendered to the
Company shall be cancelled at the time of transfer, and before a new certificate
or certificates shall be issued in lieu thereof. Duplicate certificates of stock
shall be issued only upon giving such security as may be satisfactory to the
Board of Directors or the Executive Committee.
<PAGE>   26
                                                                         Page 26


            Section 3. The Board of Directors of the Company is authorized to
fix in advance a record date for the determination of the stockholders entitled
to notice of, and to vote at, any meeting of stockholders and any adjournment
thereof, or entitled to receive payment of any dividend, or to any allotment or
rights, or to exercise any rights in respect of any change, conversion or
exchange of capital stock, or in connection with obtaining the consent of
stockholders for any purpose, which record date shall not be more than 60 nor
less than 10 days proceeding the date of any meeting of stockholders or the date
for the payment of any dividend, or the date for the allotment of rights, or the
date when any change or conversion or exchange of capital stock shall go into
effect, or a date in connection with obtaining such consent.


                                   ARTICLE VI
                                      SEAL

            Section 1. The corporate seal of the Company shall be in the
following form:

                        Between two concentric circles the words "Wilmington
                        Trust Company" within the inner circle the words
                        "Wilmington, Delaware."


                                   ARTICLE VII
                                   FISCAL YEAR

            Section 1. The fiscal year of the Company shall be the calendar
year.
<PAGE>   27
                                                                         Page 27


                                  ARTICLE VIII
                     EXECUTION OF INSTRUMENTS OF THE COMPANY

            Section 1. The Chairman of the Board, the President or any Vice
President, however denominated by the Board of Directors, shall have full power
and authority to enter into, make, sign, execute, acknowledge and/or deliver and
the Secretary or any Assistant Secretary shall have full power and authority to
attest and affix the corporate seal of the Company to any and all deeds,
conveyances, assignments, releases, contracts, agreements, bonds, notes,
mortgages and all other instruments incident to the business of this Company or
in acting as executor, administrator, guardian, trustee, agent or in any other
fiduciary or representative capacity by any and every method of appointment or
by whatever person, corporation, court officer or authority in the State of
Delaware, or elsewhere, without any specific authority, ratification, approval
or confirmation by the Board of Directors or the Executive Committee, and any
and all such instruments shall have the same force and validity as though
expressly authorized by the Board of Directors and/or the Executive Committee.


                                   ARTICLE IX
               COMPENSATION OF DIRECTORS AND MEMBERS OF COMMITTEES

            Section 1. Directors and associate directors of the Company, other
than salaried officers of the Company, shall be paid such reasonable honoraria
or fees for attending meetings of the Board of Directors as the Board of
Directors may from time to time determine. Directors and associate directors who
serve as members of committees, other than salaried employees of the Company,
shall be paid such reasonable honoraria or fees for services as members of
committees as the Board of Directors shall from time to time determine and
directors and associate directors may be employed by the Company for such
special services as the Board of Directors may from time to time determine and
shall be paid for such special services so performed reasonable compensation as
may be determined by the Board of Directors.


                                    ARTICLE X
                                 INDEMNIFICATION

            Section 1. (A) The Corporation shall indemnify and hold harmless, to
the fullest extent permitted by applicable law as it presently exists or may
hereafter be amended, any person who was or is made or is threatened to be made
a party or is otherwise involved in any action, suit or proceeding, whether
civil, criminal, administrative or investigative (a "proceeding") by reason of
the fact that he, or a person for whom he is the legal representative, is or was
a director, officer, employee or agent of the Corporation or is or was serving
at the request of the Corporation as a director, officer, employee, fiduciary or
agent of another corporation or of a partnership, joint venture, trust,
enterprise or non-profit entity, including service with respect to employee
<PAGE>   28
                                                                         Page 28


benefit plans, against all liability and loss suffered and expenses reasonably
incurred by such person. The Corporation shall indemnify a person in connection
with a proceeding initiated by such person only if the proceeding was authorized
by the Board of Directors of the Corporation.

                        (B) The Corporation shall pay the expenses incurred in
defending any proceeding in advance of its final disposition, provided, however,
that the payment of expenses incurred by a Director officer in his capacity as a
Director or officer in advance of the final disposition of the proceeding shall
be made only upon receipt of an undertaking by the Director or officer to repay
all amounts advanced if it should be ultimately determined that the Director or
officer is not entitled to be indemnified under this Article or otherwise.

                        (C) If a claim for indemnification or payment of
expenses, under this Article X is not paid in full within ninety days after a
written claim therefor has been received by the Corporation the claimant may
file suit to recover the unpaid amount of such claim and, if successful in whole
or in part, shall be entitled to be paid the expense of prosecuting such claim.
In any such action the Corporation shall have the burden of proving that the
claimant was not entitled to the requested indemnification of payment of
expenses under applicable law.

                        (D) The rights conferred on any person by this Article X
shall not be exclusive of any other rights which such person may have or
hereafter acquire under any statute, provision of the Charter or Act of
Incorporation, these By-Laws, agreement, vote of stockholders or disinterested
Directors or otherwise.

                        (E) Any repeal or modification of the foregoing
provisions of this Article X shall not adversely affect any right or protection
hereunder of any person in respect of any act or omission occurring prior to the
time of such repeal or modification.


                                   ARTICLE XI
                            AMENDMENTS TO THE BY-LAWS

            Section 1. These By-Laws may be altered, amended or repealed, in
whole or in part, and any new By-Law or By-Laws adopted at any regular or
special meeting of the Board of Directors by a vote of the majority of all the
members of the Board of Directors then in office.
<PAGE>   29
                                                                         Page 29


                                    EXHIBIT C




                             SECTION 321(b) CONSENT


            Pursuant to Section 321(b) of the Trust Indenture Act of 1939, as
amended, Wilmington Trust Company hereby consents that reports of examinations
by Federal, State, Territorial or District authorities may be furnished by such
authorities to the Securities and Exchange Commission upon requests therefor.



                                             WILMINGTON TRUST COMPANY


Dated: December 10, 1998                     By:/s/ James P. Lawler           
                                                ------------------
                                             Name: James P. Lawler
                                             Title: Vice President
<PAGE>   30
                                                                         Page 30


                                    EXHIBIT D



                                     NOTICE


            This form is intended to assist state nonmember banks and savings
            banks with state publication requirements. It has not been approved
            by any state banking authorities. Refer to your appropriate state
            banking authorities for your state publication requirements.



R E P O R T   O F   C O N D I T I O N

Consolidating domestic subsidiaries of the

           WILMINGTON TRUST COMPANY       of     WILMINGTON    
                 Name of Bank                       City

in the State of   DELAWARE  , at the close of business on September 30, 1998.



<TABLE>
<CAPTION>
ASSETS
                                                                                Thousands of dollars
<S>                                                                             <C>      
Cash and balances due from depository institutions:
Noninterest-bearing balances and currency and coins ......................             180,755
Interest-bearing balances ................................................                   0
Held-to-maturity securities ..............................................             148,529
Available-for-sale securities ............................................           1,216,482
Federal funds sold and securities purchased under agreements to resell ...             203,500
Loans and lease financing receivables:
Loans and leases, net of unearned income .................................           3,951,771
LESS:  Allowance for loan and lease losses ...............................              64,835
LESS:  Allocated transfer risk reserve ...................................                   0
Loans and leases, net of unearned income, allowance, and reserve .........           3,886,936
Assets held in trading accounts ..........................................                   0
Premises and fixed assets (including capitalized leases) .................             137,819
Other real estate owned ..................................................               1,847
Investments in unconsolidated subsidiaries and associated companies ......                 997
Customers' liability to this bank on acceptances outstanding .............                   0
Intangible assets ........................................................               3,105
Other assets .............................................................              82,400
Total assets .............................................................           5,862,370
</TABLE>



CONTINUED ON NEXT PAGE
<PAGE>   31
                                                                        Page 31 

<TABLE>
<S>                                                                                  <C>      
LIABILITIES

Deposits:
In domestic offices ..........................................................       4,338,785
     Noninterest-bearing .....................................................         792,528
     Interest-bearing ........................................................       3,546,257
Federal funds purchased and Securities sold under agreements to repurchase ...         249,670
Demand notes issued to the U.S. Treasury .....................................          74,347
Trading liabilities (from Schedule RC-D) .....................................               0
Other borrowed money: ........................................................         ///////
     With original maturity of one year or less ..............................         576,507
     With original maturity of more than one year ............................          43,000
Bank's liability on acceptances executed and outstanding .....................               0
Subordinated notes and debentures ............................................               0
Other liabilities (from Schedule RC-G) .......................................         104,687
Total liabilities ............................................................       5,386,996


EQUITY CAPITAL

Perpetual preferred stock and related surplus ................................               0
Common Stock .................................................................             500
Surplus (exclude all surplus related to preferred stock) .....................          62,118
Undivided profits and capital reserves .......................................         399,222
Net unrealized holding gains (losses) on available-for-sale securities .......          13,534
Total equity capital .........................................................         475,374
Total liabilities, limited-life preferred stock, and equity capital ..........       5,862,370
</TABLE>


<PAGE>   1
                                                                    EXHIBIT 25.2




                                                                Registration No.



                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM T-1

         STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939
                  OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE

   CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO
                             SECTION 305(b)(2) ____

                            WILMINGTON TRUST COMPANY
               (Exact name of trustee as specified in its charter)


        Delaware                                        51-0055023
(State of incorporation)                    (I.R.S. employer identification no.)

                               Rodney Square North
                            1100 North Market Street
                           Wilmington, Delaware 19890
                    (Address of principal executive offices)

                               Cynthia L. Corliss
                        Vice President and Trust Counsel
                            Wilmington Trust Company
                               Rodney Square North
                           Wilmington, Delaware 19890
                                 (302) 651-8516
            (Name, address and telephone number of agent for service)

                           AMERICA WEST AIRLINES, INC.

               (Exact name of obligor as specified in its charter)

        Delaware                                        86-0418245
(State of incorporation)                    (I.R.S. employer identification no.)

4000 E. Sky Harbor Boulevard
      Phoenix, Arizona                                  85034-3899
(Address of principal executive offices)                (Zip Code)


                    Pass Through Certificates, Series 1998-1B
<PAGE>   2
                                                                          Page 2


                       (Title of the indenture securities)
<PAGE>   3
                                                                          Page 3


ITEM 1.     GENERAL INFORMATION.

                    Furnish the following information as to the trustee:

            (a)     Name and address of each examining or supervising authority
                    to which it is subject.

                    Federal Deposit Insurance Co.        State Bank Commissioner
                    Five Penn Center                     Dover, Delaware
                    Suite #2901
                    Philadelphia, PA

            (b)     Whether it is authorized to exercise corporate trust powers.

                    The trustee is authorized to exercise corporate trust
                    powers.

ITEM 2.     AFFILIATIONS WITH THE OBLIGOR.

                    If the obligor is an affiliate of the trustee, describe each
            affiliation:

                    Based upon an examination of the books and records of the
            trustee and upon information furnished by the obligor, the obligor
            is not an affiliate of the trustee.

ITEM 3.     LIST OF EXHIBITS.

                    List below all exhibits filed as part of this Statement of
            Eligibility and Qualification.

            A.      Copy of the Charter of Wilmington Trust Company, which
                    includes the certificate of authority of Wilmington Trust
                    Company to commence business and the authorization of
                    Wilmington Trust Company to exercise corporate trust powers.

            B.      Copy of By-Laws of Wilmington Trust Company.

            C.      Consent of Wilmington Trust Company required by Section
                    321(b) of Trust Indenture Act.

            D.      Copy of most recent Report of Condition of Wilmington Trust
                    Company.

            Pursuant to the requirements of the Trust Indenture Act of 1939, as
amended, the trustee, Wilmington Trust Company, a corporation organized and
existing under the laws of Delaware, has duly caused this Statement of
Eligibility to be signed on its behalf by the undersigned, thereunto duly
authorized, all in the City of Wilmington and State of Delaware on the 10th day
of December, 1998.


                                             WILMINGTON TRUST COMPANY
[SEAL]

Attest:/s/ Christopher L. Kaiser             By:/s/ James P. Lawler            
       -------------------------                -------------------
       Assistant Secretary                   Name:  James P. Lawler
                                             Title:  Vice President
<PAGE>   4
                                                                          Page 4


                                    EXHIBIT A

                                 AMENDED CHARTER

                            WILMINGTON TRUST COMPANY

                              WILMINGTON, DELAWARE

                           AS EXISTING ON MAY 9, 1987
<PAGE>   5
                                                                          Page 5


                                 AMENDED CHARTER

                                       OR

                              ACT OF INCORPORATION

                                       OF

                            WILMINGTON TRUST COMPANY

            WILMINGTON TRUST COMPANY, originally incorporated by an Act of the
General Assembly of the State of Delaware, entitled "An Act to Incorporate the
Delaware Guarantee and Trust Company", approved March 2, A.D. 1901, and the name
of which company was changed to "WILMINGTON TRUST COMPANY" by an amendment filed
in the Office of the Secretary of State on March 18, A.D. 1903, and the Charter
or Act of Incorporation of which company has been from time to time amended and
changed by merger agreements pursuant to the corporation law for state banks and
trust companies of the State of Delaware, does hereby alter and amend its
Charter or Act of Incorporation so that the same as so altered and amended shall
in its entirety read as follows:

            FIRST: - The name of this corporation is WILMINGTON TRUST COMPANY.

            SECOND: - The location of its principal office in the State of
            Delaware is at Rodney Square North, in the City of Wilmington,
            County of New Castle; the name of its resident agent is WILMINGTON
            TRUST COMPANY whose address is Rodney Square North, in said City. In
            addition to such principal office, the said corporation maintains
            and operates branch offices in the City of Newark, New Castle
            County, Delaware, the Town of Newport, New Castle County, Delaware,
            at Claymont, New Castle County, Delaware, at Greenville, New Castle
            County Delaware, and at Milford Cross Roads, New Castle County,
            Delaware, and shall be empowered to open, maintain and operate
            branch offices at Ninth and Shipley Streets, 418 Delaware Avenue,
            2120 Market Street, and 3605 Market Street, all in the City of
            Wilmington, New Castle County, Delaware, and such other branch
            offices or places of business as may be authorized from time to time
            by the agency or agencies of the government of the State of Delaware
            empowered to confer such authority.

            THIRD: - (a) The nature of the business and the objects and purposes
            proposed to be transacted, promoted or carried on by this
            Corporation are to do any or all of the things herein mentioned as
            fully and to the same extent as natural persons might or could do
            and in any part of the world, viz.:

                    (1) To sue and be sued, complain and defend in any Court of
                    law or equity and to make and use a common seal, and alter
                    the seal at pleasure, to hold, purchase, convey, mortgage or
                    otherwise deal in real 
<PAGE>   6
                                                                          Page 6


                    and personal estate and property, and to appoint such
                    officers and agents as the business of the Corporation shall
                    require, to make by-laws not inconsistent with the
                    Constitution or laws of the United States or of this State,
                    to discount bills, notes or other evidences of debt, to
                    receive deposits of money, or securities for money, to buy
                    gold and silver bullion and foreign coins, to buy and sell
                    bills of exchange, and generally to use, exercise and enjoy
                    all the powers, rights, privileges and franchises incident
                    to a corporation which are proper or necessary for the
                    transaction of the business of the Corporation hereby
                    created.

                    (2) To insure titles to real and personal property, or any
                    estate or interests therein, and to guarantee the holder of
                    such property, real or personal, against any claim or
                    claims, adverse to his interest therein, and to prepare and
                    give certificates of title for any lands or premises in the
                    State of Delaware, or elsewhere.

                    (3) To act as factor, agent, broker or attorney in the
                    receipt, collection, custody, investment and management of
                    funds, and the purchase, sale, management and disposal of
                    property of all descriptions, and to prepare and execute all
                    papers which may be necessary or proper in such business.

                    (4) To prepare and draw agreements, contracts, deeds,
                    leases, conveyances, mortgages, bonds and legal papers of
                    every description, and to carry on the business of
                    conveyancing in all its branches.

                    (5) To receive upon deposit for safekeeping money, jewelry,
                    plate, deeds, bonds and any and all other personal property
                    of every sort and kind, from executors, administrators,
                    guardians, public officers, courts, receivers, assignees,
                    trustees, and from all fiduciaries, and from all other
                    persons and individuals, and from all corporations whether
                    state, municipal, corporate or private, and to rent boxes,
                    safes, vaults and other receptacles for such property.

                    (6) To act as agent or otherwise for the purpose of
                    registering, issuing, certificating, countersigning,
                    transferring or underwriting the stock, bonds or other
                    obligations of any corporation, association, state or
                    municipality, and may receive and manage any sinking fund
                    therefor on such terms as may be agreed upon between the two
                    parties, and in like manner may act as Treasurer of any
                    corporation or municipality.

                    (7) To act as Trustee under any deed of trust, mortgage,
                    bond or other instrument issued by any state, municipality,
                    body politic, corporation, association or person, either
                    alone or in conjunction with any other person or persons,
                    corporation or corporations.
<PAGE>   7
                                                                          Page 7


                    (8) To guarantee the validity, performance or effect of any
                    contract or agreement, and the fidelity of persons holding
                    places of responsibility or trust; to become surety for any
                    person, or persons, for the faithful performance of any
                    trust, office, duty, contract or agreement, either by itself
                    or in conjunction with any other person, or persons,
                    corporation, or corporations, or in like manner become
                    surety upon any bond, recognizance, obligation, judgment,
                    suit, order, or decree to be entered in any court of record
                    within the State of Delaware or elsewhere, or which may now
                    or hereafter be required by any law, judge, officer or court
                    in the State of Delaware or elsewhere.

                    (9) To act by any and every method of appointment as
                    trustee, trustee in bankruptcy, receiver, assignee, assignee
                    in bankruptcy, executor, administrator, guardian, bailee, or
                    in any other trust capacity in the receiving, holding,
                    managing, and disposing of any and all estates and property,
                    real, personal or mixed, and to be appointed as such
                    trustee, trustee in bankruptcy, receiver, assignee, assignee
                    in bankruptcy, executor, administrator, guardian or bailee
                    by any persons, corporations, court, officer, or authority,
                    in the State of Delaware or elsewhere; and whenever this
                    Corporation is so appointed by any person, corporation,
                    court, officer or authority such trustee, trustee in
                    bankruptcy, receiver, assignee, assignee in bankruptcy,
                    executor, administrator, guardian, bailee, or in any other
                    trust capacity, it shall not be required to give bond with
                    surety, but its capital stock shall be taken and held as
                    security for the performance of the duties devolving upon it
                    by such appointment.

                    (10) And for its care, management and trouble, and the
                    exercise of any of its powers hereby given, or for the
                    performance of any of the duties which it may undertake or
                    be called upon to perform, or for the assumption of any
                    responsibility the said Corporation may be entitled to
                    receive a proper compensation.

                    (11) To purchase, receive, hold and own bonds, mortgages,
                    debentures, shares of capital stock, and other securities,
                    obligations, contracts and evidences of indebtedness, of any
                    private, public or municipal corporation within and without
                    the State of Delaware, or of the Government of the United
                    States, or of any state, territory, colony, or possession
                    thereof, or of any foreign government or country; to
                    receive, collect, receipt for, and dispose of interest,
                    dividends and income upon and from any of the bonds,
                    mortgages, debentures, notes, shares of capital stock,
                    securities, obligations, contracts, evidences of
                    indebtedness and other property held and owned by it, and to
                    exercise in respect of all such bonds, mortgages,
                    debentures, notes, shares of capital stock, securities,
                    obligations, contracts, evidences of indebtedness and other
                    property, any and all the rights, powers and privileges of
                    individual owners thereof, including the right to vote
                    thereon;
<PAGE>   8
                                                                          Page 8


                    to invest and deal in and with any of the moneys of the
                    Corporation upon such securities and in such manner as it
                    may think fit and proper, and from time to time to vary or
                    realize such investments; to issue bonds and secure the same
                    by pledges or deeds of trust or mortgages of or upon the
                    whole or any part of the property held or owned by the
                    Corporation, and to sell and pledge such bonds, as and when
                    the Board of Directors shall determine, and in the promotion
                    of its said corporate business of investment and to the
                    extent authorized by law, to lease, purchase, hold, sell,
                    assign, transfer, pledge, mortgage and convey real and
                    personal property of any name and nature and any estate or
                    interest therein.

            (b) In furtherance of, and not in limitation, of the powers
            conferred by the laws of the State of Delaware, it is hereby
            expressly provided that the said Corporation shall also have the
            following powers:

                    (1) To do any or all of the things herein set forth, to the
                    same extent as natural persons might or could do, and in any
                    part of the world.

                    (2) To acquire the good will, rights, property and
                    franchises and to undertake the whole or any part of the
                    assets and liabilities of any person, firm, association or
                    corporation, and to pay for the same in cash, stock of this
                    Corporation, bonds or otherwise; to hold or in any manner to
                    dispose of the whole or any part of the property so
                    purchased; to conduct in any lawful manner the whole or any
                    part of any business so acquired, and to exercise all the
                    powers necessary or convenient in and about the conduct and
                    management of such business.

                    (3) To take, hold, own, deal in, mortgage or otherwise lien,
                    and to lease, sell, exchange, transfer, or in any manner
                    whatever dispose of property, real, personal or mixed,
                    wherever situated.

                    (4) To enter into, make, perform and carry out contracts of
                    every kind with any person, firm, association or
                    corporation, and, without limit as to amount, to draw, make,
                    accept, endorse, discount, execute and issue promissory
                    notes, drafts, bills of exchange, warrants, bonds,
                    debentures, and other negotiable or transferable
                    instruments.

                    (5) To have one or more offices, to carry on all or any of
                    its operations and businesses, without restriction to the
                    same extent as natural persons might or could do, to
                    purchase or otherwise acquire, to hold, own, to mortgage,
                    sell, convey or otherwise dispose of, real and personal
                    property, of every class and description, in any State,
                    District, Territory or Colony of the United States, and in
                    any foreign country or place.

                    (6) It is the intention that the objects, purposes and
                    powers specified and clauses contained in this paragraph
                    shall (except where otherwise 
<PAGE>   9
                                                                          Page 9


                    expressed in said paragraph) be nowise limited or restricted
                    by reference to or inference from the terms of any other
                    clause of this or any other paragraph in this charter, but
                    that the objects, purposes and powers specified in each of
                    the clauses of this paragraph shall be regarded as
                    independent objects, purposes and powers.

            FOURTH: - (a) The total number of shares of all classes of stock
            which the Corporation shall have authority to issue is forty-one
            million (41,000,000) shares, consisting of:

                    (1) One million (1,000,000) shares of Preferred stock, par
                    value $10.00 per share (hereinafter referred to as
                    "Preferred Stock"); and

                    (2) Forty million (40,000,000) shares of Common Stock, par
                    value $1.00 per share (hereinafter referred to as "Common
                    Stock").

            (b) Shares of Preferred Stock may be issued from time to time in one
            or more series as may from time to time be determined by the Board
            of Directors each of said series to be distinctly designated. All
            shares of any one series of Preferred Stock shall be alike in every
            particular, except that there may be different dates from which
            dividends, if any, thereon shall be cumulative, if made cumulative.
            The voting powers and the preferences and relative, participating,
            optional and other special rights of each such series, and the
            qualifications, limitations or restrictions thereof, if any, may
            differ from those of any and all other series at any time
            outstanding; and, subject to the provisions of subparagraph 1 of
            Paragraph (c) of this Article FOURTH, the Board of Directors of the
            Corporation is hereby expressly granted authority to fix by
            resolution or resolutions adopted prior to the issuance of any
            shares of a particular series of Preferred Stock, the voting powers
            and the designations, preferences and relative, optional and other
            special rights, and the qualifications, limitations and restrictions
            of such series, including, but without limiting the generality of
            the foregoing, the following:

                    (1) The distinctive designation of, and the number of shares
                    of Preferred Stock which shall constitute such series, which
                    number may be increased (except where otherwise provided by
                    the Board of Directors) or decreased (but not below the
                    number of shares thereof then outstanding) from time to time
                    by like action of the Board of Directors;

                    (2) The rate and times at which, and the terms and
                    conditions on which, dividends, if any, on Preferred Stock
                    of such series shall be paid, the extent of the preference
                    or relation, if any, of such dividends to the dividends
                    payable on any other class or classes, or series of the same
                    or other class of stock and whether such dividends shall be
                    cumulative or non-cumulative;
<PAGE>   10
                                                                         Page 10


                    (3) The right, if any, of the holders of Preferred Stock of
                    such series to convert the same into or exchange the same
                    for, shares of any other class or classes or of any series
                    of the same or any other class or classes of stock of the
                    Corporation and the terms and conditions of such conversion
                    or exchange;

                    (4) Whether or not Preferred Stock of such series shall be
                    subject to redemption, and the redemption price or prices
                    and the time or times at which, and the terms and conditions
                    on which, Preferred Stock of such series may be redeemed.

                    (5) The rights, if any, of the holders of Preferred Stock of
                    such series upon the voluntary or involuntary liquidation,
                    merger, consolidation, distribution or sale of assets,
                    dissolution or winding-up, of the Corporation.

                    (6) The terms of the sinking fund or redemption or purchase
                    account, if any, to be provided for the Preferred Stock of
                    such series; and

                    (7) The voting powers, if any, of the holders of such series
                    of Preferred Stock which may, without limiting the
                    generality of the foregoing include the right, voting as a
                    series or by itself or together with other series of
                    Preferred Stock or all series of Preferred Stock as a class,
                    to elect one or more directors of the Corporation if there
                    shall have been a default in the payment of dividends on any
                    one or more series of Preferred Stock or under such
                    circumstances and on such conditions as the Board of
                    Directors may determine.

            (c) (1) After the requirements with respect to preferential
            dividends on the Preferred Stock (fixed in accordance with the
            provisions of section (b) of this Article FOURTH), if any, shall
            have been met and after the Corporation shall have complied with all
            the requirements, if any, with respect to the setting aside of sums
            as sinking funds or redemption or purchase accounts (fixed in
            accordance with the provisions of section (b) of this Article
            FOURTH), and subject further to any conditions which may be fixed in
            accordance with the provisions of section (b) of this Article
            FOURTH, then and not otherwise the holders of Common Stock shall be
            entitled to receive such dividends as may be declared from time to
            time by the Board of Directors.

                    (2) After distribution in full of the preferential amount,
                    if any, (fixed in accordance with the provisions of section
                    (b) of this Article FOURTH), to be distributed to the
                    holders of Preferred Stock in the event of voluntary or
                    involuntary liquidation, distribution or sale of assets,
                    dissolution or winding-up, of the Corporation, the holders
                    of the Common Stock shall be entitled to receive all of the
                    remaining assets of the Corporation, tangible and
                    intangible, of whatever kind available for distribution to
<PAGE>   11
                                                                         Page 11


                    stockholders ratably in proportion to the number of shares
                    of Common Stock held by them respectively.

                    (3) Except as may otherwise be required by law or by the
                    provisions of such resolution or resolutions as may be
                    adopted by the Board of Directors pursuant to section (b) of
                    this Article FOURTH, each holder of Common Stock shall have
                    one vote in respect of each share of Common Stock held on
                    all matters voted upon by the stockholders.

            (d) No holder of any of the shares of any class or series of stock
            or of options, warrants or other rights to purchase shares of any
            class or series of stock or of other securities of the Corporation
            shall have any preemptive right to purchase or subscribe for any
            unissued stock of any class or series or any additional shares of
            any class or series to be issued by reason of any increase of the
            authorized capital stock of the Corporation of any class or series,
            or bonds, certificates of indebtedness, debentures or other
            securities convertible into or exchangeable for stock of the
            Corporation of any class or series, or carrying any right to
            purchase stock of any class or series, but any such unissued stock,
            additional authorized issue of shares of any class or series of
            stock or securities convertible into or exchangeable for stock, or
            carrying any right to purchase stock, may be issued and disposed of
            pursuant to resolution of the Board of Directors to such persons,
            firms, corporations or associations, whether such holders or others,
            and upon such terms as may be deemed advisable by the Board of
            Directors in the exercise of its sole discretion.

            (e) The relative powers, preferences and rights of each series of
            Preferred Stock in relation to the relative powers, preferences and
            rights of each other series of Preferred Stock shall, in each case,
            be as fixed from time to time by the Board of Directors in the
            resolution or resolutions adopted pursuant to authority granted in
            section (b) of this Article FOURTH and the consent, by class or
            series vote or otherwise, of the holders of such of the series of
            Preferred Stock as are from time to time outstanding shall not be
            required for the issuance by the Board of Directors of any other
            series of Preferred Stock whether or not the powers, preferences and
            rights of such other series shall be fixed by the Board of Directors
            as senior to, or on a parity with, the powers, preferences and
            rights of such outstanding series, or any of them; provided,
            however, that the Board of Directors may provide in the resolution
            or resolutions as to any series of Preferred Stock adopted pursuant
            to section (b) of this Article FOURTH that the consent of the
            holders of a majority (or such greater proportion as shall be
            therein fixed) of the outstanding shares of such series voting
            thereon shall be required for the issuance of any or all other
            series of Preferred Stock.

            (f) Subject to the provisions of section (e), shares of any series
            of Preferred Stock may be issued from time to time as the Board of
            Directors of the Corporation shall determine and on such terms and
            for such consideration as
<PAGE>   12
                                                                         Page 12


            shall be fixed by the Board of Directors.

            (g) Shares of Common Stock may be issued from time to time as the
            Board of Directors of the Corporation shall determine and on such
            terms and for such consideration as shall be fixed by the Board of
            Directors.

            (h) The authorized amount of shares of Common Stock and of Preferred
            Stock may, without a class or series vote, be increased or decreased
            from time to time by the affirmative vote of the holders of a
            majority of the stock of the Corporation entitled to vote thereon.

            FIFTH: - (a) The business and affairs of the Corporation shall be
            conducted and managed by a Board of Directors. The number of
            directors constituting the entire Board shall be not less than five
            nor more than twenty-five as fixed from time to time by vote of a
            majority of the whole Board, provided, however, that the number of
            directors shall not be reduced so as to shorten the term of any
            director at the time in office, and provided further, that the
            number of directors constituting the whole Board shall be
            twenty-four until otherwise fixed by a majority of the whole Board.

            (b) The Board of Directors shall be divided into three classes, as
            nearly equal in number as the then total number of directors
            constituting the whole Board permits, with the term of office of one
            class expiring each year. At the annual meeting of stockholders in
            1982, directors of the first class shall be elected to hold office
            for a term expiring at the next succeeding annual meeting, directors
            of the second class shall be elected to hold office for a term
            expiring at the second succeeding annual meeting and directors of
            the third class shall be elected to hold office for a term expiring
            at the third succeeding annual meeting. Any vacancies in the Board
            of Directors for any reason, and any newly created directorships
            resulting from any increase in the directors, may be filled by the
            Board of Directors, acting by a majority of the directors then in
            office, although less than a quorum, and any directors so chosen
            shall hold office until the next annual election of directors. At
            such election, the stockholders shall elect a successor to such
            director to hold office until the next election of the class for
            which such director shall have been chosen and until his successor
            shall be elected and qualified. No decrease in the number of
            directors shall shorten the term of any incumbent director.

            (c) Notwithstanding any other provisions of this Charter or Act of
            Incorporation or the By-Laws of the Corporation (and notwithstanding
            the fact that some lesser percentage may be specified by law, this
            Charter or Act of Incorporation or the By-Laws of the Corporation),
            any director or the entire Board of Directors of the Corporation may
            be removed at any time without cause, but only by the affirmative
            vote of the holders of two-thirds or more of the outstanding shares
            of capital stock of the Corporation entitled to vote generally in
            the election of directors (considered for this purpose as one class)
            cast at a 
<PAGE>   13
                                                                         Page 13


            meeting of the stockholders called for that purpose.

            (d) Nominations for the election of directors may be made by the
            Board of Directors or by any stockholder entitled to vote for the
            election of directors. Such nominations shall be made by notice in
            writing, delivered or mailed by first class United States mail,
            postage prepaid, to the Secretary of the Corporation not less than
            14 days nor more than 50 days prior to any meeting of the
            stockholders called for the election of directors; provided,
            however, that if less than 21 days' notice of the meeting is given
            to stockholders, such written notice shall be delivered or mailed,
            as prescribed, to the Secretary of the Corporation not later than
            the close of the seventh day following the day on which notice of
            the meeting was mailed to stockholders. Notice of nominations which
            are proposed by the Board of Directors shall be given by the
            Chairman on behalf of the Board.

            (e) Each notice under subsection (d) shall set forth (i) the name,
            age, business address and, if known, residence address of each
            nominee proposed in such notice, (ii) the principal occupation or
            employment of such nominee and (iii) the number of shares of stock
            of the Corporation which are beneficially owned by each such
            nominee.

            (f) The Chairman of the meeting may, if the facts warrant, determine
            and declare to the meeting that a nomination was not made in
            accordance with the foregoing procedure, and if he should so
            determine, he shall so declare to the meeting and the defective
            nomination shall be disregarded.

            (g) No action required to be taken or which may be taken at any
            annual or special meeting of stockholders of the Corporation may be
            taken without a meeting, and the power of stockholders to consent in
            writing, without a meeting, to the taking of any action is
            specifically denied.

            SIXTH: - The Directors shall choose such officers, agent and
            servants as may be provided in the By-Laws as they may from time to
            time find necessary or proper.

            SEVENTH: - The Corporation hereby created is hereby given the same
            powers, rights and privileges as may be conferred upon corporations
            organized under the Act entitled "An Act Providing a General
            Corporation Law", approved March 10, 1899, as from time to time
            amended.

            EIGHTH: - This Act shall be deemed and taken to be a private Act.

            NINTH: - This Corporation is to have perpetual existence.

            TENTH: - The Board of Directors, by resolution passed by a majority
            of the whole Board, may designate any of their number to constitute
            an Executive 
<PAGE>   14
                                                                         Page 14


            Committee, which Committee, to the extent provided in said
            resolution, or in the By-Laws of the Company, shall have and may
            exercise all of the powers of the Board of Directors in the
            management of the business and affairs of the Corporation, and shall
            have power to authorize the seal of the Corporation to be affixed to
            all papers which may require it.

            ELEVENTH: - The private property of the stockholders shall not be
            liable for the payment of corporate debts to any extent whatever.

            TWELFTH: - The Corporation may transact business in any part of the
            world.

            THIRTEENTH: - The Board of Directors of the Corporation is expressly
            authorized to make, alter or repeal the By-Laws of the Corporation
            by a vote of the majority of the entire Board. The stockholders may
            make, alter or repeal any By-Law whether or not adopted by them,
            provided however, that any such additional By-Laws, alterations or
            repeal may be adopted only by the affirmative vote of the holders of
            two-thirds or more of the outstanding shares of capital stock of the
            Corporation entitled to vote generally in the election of directors
            (considered for this purpose as one class).

            FOURTEENTH: - Meetings of the Directors may be held outside
            of the State of Delaware at such places as may be from time to time
            designated by the Board, and the Directors may keep the books of the
            Company outside of the State of Delaware at such places as may be
            from time to time designated by them.

            FIFTEENTH: - (a) In addition to any affirmative vote required by
            law, and except as otherwise expressly provided in sections (b) and
            (c) of this Article FIFTEENTH:

                    (A) any merger or consolidation of the Corporation or any
                    Subsidiary (as hereinafter defined) with or into (i) any
                    Interested Stockholder (as hereinafter defined) or (ii) any
                    other corporation (whether or not itself an Interested
                    Stockholder), which, after such merger or consolidation,
                    would be an Affiliate (as hereinafter defined) of an
                    Interested Stockholder, or

                    (B) any sale, lease, exchange, mortgage, pledge, transfer or
                    other disposition (in one transaction or a series of related
                    transactions) to or with any Interested Stockholder or any
                    Affiliate of any Interested Stockholder of any assets of the
                    Corporation or any Subsidiary having an aggregate fair
                    market value of $1,000,000 or more, or

                    (C) the issuance or transfer by the Corporation or any
                    Subsidiary (in one transaction or a series of related
                    transactions) of any securities of the Corporation or any
                    Subsidiary to any Interested Stockholder or any Affiliate of
                    any Interested Stockholder in exchange for cash, securities
                    or 
<PAGE>   15
                                                                         Page 15


                    other property (or a combination thereof) having an
                    aggregate fair market value of $1,000,000 or more, or

                    (D) the adoption of any plan or proposal for the liquidation
                    or dissolution of the Corporation, or

                    (E) any reclassification of securities (including any
                    reverse stock split), or recapitalization of the
                    Corporation, or any merger or consolidation of the
                    Corporation with any of its Subsidiaries or any similar
                    transaction (whether or not with or into or otherwise
                    involving an Interested Stockholder) which has the effect,
                    directly or indirectly, of increasing the proportionate
                    share of the outstanding shares of any class of equity or
                    convertible securities of the Corporation or any Subsidiary
                    which is directly or indirectly owned by any Interested
                    Stockholder, or any Affiliate of any Interested Stockholder,

shall require the affirmative vote of the holders of at least two-thirds of the
outstanding shares of capital stock of the Corporation entitled to vote
generally in the election of directors, considered for the purpose of this
Article FIFTEENTH as one class ("Voting Shares"). Such affirmative vote shall be
required notwithstanding the fact that no vote may be required, or that some
lesser percentage may be specified, by law or in any agreement with any national
securities exchange or otherwise.

                      (2) The term "business combination" as used in this
                      Article FIFTEENTH shall mean any transaction which is
                      referred to any one or more of clauses (A) through (E) of
                      paragraph 1 of the section (a).

                    (b) The provisions of section (a) of this Article FIFTEENTH
                    shall not be applicable to any particular business
                    combination and such business combination shall require only
                    such affirmative vote as is required by law and any other
                    provisions of the Charter or Act of Incorporation of By-Laws
                    if such business combination has been approved by a majority
                    of the whole Board.

                    (c) For the purposes of this Article FIFTEENTH:

            (1) A "person" shall mean any individual firm, corporation or other
            entity.

            (2) "Interested Stockholder" shall mean, in respect of any business
            combination, any person (other than the Corporation or any
            Subsidiary) who or which as of the record date for the determination
            of stockholders entitled to notice of and to vote on such business
            combination, or immediately prior to the consummation of any such
            transaction:

                    (A) is the beneficial owner, directly or indirectly, of more
                    than 10% of the Voting Shares, or
<PAGE>   16
                                                                         Page 16


                    (B) is an Affiliate of the Corporation and at any time
                    within two years prior thereto was the beneficial owner,
                    directly or indirectly, of not less than 10% of the then
                    outstanding voting Shares, or

                    (C) is an assignee of or has otherwise succeeded in any
                    share of capital stock of the Corporation which were at any
                    time within two years prior thereto beneficially owned by
                    any Interested Stockholder, and such assignment or
                    succession shall have occurred in the course of a
                    transaction or series of transactions not involving a public
                    offering within the meaning of the Securities Act of 1933.

            (3) A person shall be the "beneficial owner" of any Voting Shares:

                    (A) which such person or any of its Affiliates and
                    Associates (as hereafter defined) beneficially own, directly
                    or indirectly, or

                    (B) which such person or any of its Affiliates or Associates
                    has (i) the right to acquire (whether such right is
                    exercisable immediately or only after the passage of time),
                    pursuant to any agreement, arrangement or understanding or
                    upon the exercise of conversion rights, exchange rights,
                    warrants or options, or otherwise, or (ii) the right to vote
                    pursuant to any agreement, arrangement or understanding, or

                    (C) which are beneficially owned, directly or indirectly, by
                    any other person with which such first mentioned person or
                    any of its Affiliates or Associates has any agreement,
                    arrangement or understanding for the purpose of acquiring,
                    holding, voting or disposing of any shares of capital stock
                    of the Corporation.

            (4) The outstanding Voting Shares shall include shares deemed owned
            through application of paragraph (3) above but shall not include any
            other Voting Shares which may be issuable pursuant to any agreement,
            or upon exercise of conversion rights, warrants or options or
            otherwise.

            (5) "Affiliate" and "Associate" shall have the respective meanings
            given those terms in Rule 12b-2 of the General Rules and Regulations
            under the Securities Exchange Act of 1934, as in effect on December
            31, 1981.

            (6) "Subsidiary" shall mean any corporation of which a majority of
            any class of equity security (as defined in Rule 3a11-1 of the
            General Rules and Regulations under the Securities Exchange Act of
            1934, as in effect in December 31, 1981) is owned, directly or
            indirectly, by the Corporation; provided, however, that for the
            purposes of the definition of Investment Stockholder set forth in
            paragraph (2) of this section (c), the term "Subsidiary" shall mean
            only a corporation of which a majority of each class of equity
<PAGE>   17
                                                                         Page 17


            security is owned, directly or indirectly, by the Corporation.

                    (d) majority of the directors shall have the power and duty
                    to determine for the purposes of this Article FIFTEENTH on
                    the basis of information known to them, (1) the number of
                    Voting Shares beneficially owned by any person (2) whether a
                    person is an Affiliate or Associate of another, (3) whether
                    a person has an agreement, arrangement or understanding with
                    another as to the matters referred to in paragraph (3) of
                    section (c), or (4) whether the assets subject to any
                    business combination or the consideration received for the
                    issuance or transfer of securities by the Corporation, or
                    any Subsidiary has an aggregate fair market value of
                    $1,000,000 or more.

                    (e) Nothing contained in this Article FIFTEENTH shall be
                    construed to relieve any Interested Stockholder from any
                    fiduciary obligation imposed by law.

            SIXTEENTH: Notwithstanding any other provision of this Charter or
            Act of Incorporation or the By-Laws of the Corporation (and in
            addition to any other vote that may be required by law, this Charter
            or Act of Incorporation by the By-Laws), the affirmative vote of the
            holders of at least two-thirds of the outstanding shares of the
            capital stock of the Corporation entitled to vote generally in the
            election of directors (considered for this purpose as one class)
            shall be required to amend, alter or repeal any provision of
            Articles FIFTH, THIRTEENTH, FIFTEENTH or SIXTEENTH of this Charter
            or Act of Incorporation.

            SEVENTEENTH: (a) a Director of this Corporation shall not be liable
            to the Corporation or its stockholders for monetary damages for
            breach of fiduciary duty as a Director, except to the extent such
            exemption from liability or limitation thereof is not permitted
            under the Delaware General Corporation Laws as the same exists or
            may hereafter be amended.

                    (b) Any repeal or modification of the foregoing paragraph
                    shall not adversely affect any right or protection of a
                    Director of the Corporation existing hereunder with respect
                    to any act or omission occurring prior to the time of such
                    repeal or modification."
<PAGE>   18
                                                                         Page 18


                                    EXHIBIT B

                                     BY-LAWS


                            WILMINGTON TRUST COMPANY

                              WILMINGTON, DELAWARE

                         AS EXISTING ON JANUARY 16, 1997
<PAGE>   19
                                                                         Page 19






                       BY-LAWS OF WILMINGTON TRUST COMPANY


                                    ARTICLE I
                             STOCKHOLDERS' MEETINGS

            Section 1. The Annual Meeting of Stockholders shall be held on the
third Thursday in April each year at the principal office at the Company or at
such other date, time, or place as may be designated by resolution by the Board
of Directors.

            Section 2. Special meetings of all stockholders may be called at any
time by the Board of Directors, the Chairman of the Board or the President.

            Section 3. Notice of all meetings of the stockholders shall be given
by mailing to each stockholder at least ten (10) days before said meeting, at
his last known address, a written or printed notice fixing the time and place of
such meeting.

            Section 4. A majority in the amount of the capital stock of the
Company issued and outstanding on the record date, as herein determined, shall
constitute a quorum at all meetings of stockholders for the transaction of any
business, but the holders of a small number of shares may adjourn, from time to
time, without further notice, until a quorum is secured. At each annual or
special meeting of stockholders, each stockholder shall be entitled to one vote,
either in person or by proxy, for each shares of stock registered in the
stockholder's name on the books of the Company on the record date for any such
meeting as determined herein.


                                   ARTICLE II
                                    DIRECTORS

            Section 1. The number and classification of the Board of Directors
shall be as set forth in the Charter of the Bank.

            Section 2. No person who has attained the age of seventy-two (72)
years shall be nominated for election to the Board of Directors of the Company,
provided, however, that this limitation shall not apply to any person who was
serving as director of the Company on September 16, 1971.

            Section 3. The class of Directors so elected shall hold office for
three years or until their successors are elected and qualified.

            Section 4. The affairs and business of the Company shall be managed
and conducted by the Board of Directors.

            Section 5. The Board of Directors shall meet at the principal office
of the Company or elsewhere in its discretion at such times to be determined by
a majority of 
<PAGE>   20
                                                                         Page 20


its members, or at the call of the Chairman of the Board of Directors or the
President.

            Section 6. Special meetings of the Board of Directors may be called
at any time by the Chairman of the Board of Directors or by the President, and
shall be called upon the written request of a majority of the directors.

            Section 7. A majority of the directors elected and qualified shall
be necessary to constitute a quorum for the transaction of business at any
meeting of the Board of Directors.

            Section 8. Written notice shall be sent by mail to each director of
any special meeting of the Board of Directors, and of any change in the time or
place of any regular meeting, stating the time and place of such meeting, which
shall be mailed not less than two days before the time of holding such meeting.

            Section 9. In the event of the death, resignation, removal,
inability to act, or disqualification of any director, the Board of Directors,
although less than a quorum, shall have the right to elect the successor who
shall hold office for the remainder of the full term of the class of directors
in which the vacancy occurred, and until such director's successor shall have
been duly elected and qualified.

            Section 10. The Board of Directors at its first meeting after its
election by the stockholders shall appoint an Executive Committee, a Trust
Committee, an Audit Committee and a Compensation Committee, and shall elect from
its own members a Chairman of the Board of Directors and a President who may be
the same person. The Board of Directors shall also elect at such meeting a
Secretary and a Treasurer, who may be the same person, may appoint at any time
such other committees and elect or appoint such other officers as it may deem
advisable. The Board of Directors may also elect at such meeting one or more
Associate Directors.

            Section 11. The Board of Directors may at any time remove, with or
without cause, any member of any Committee appointed by it or any associate
director or officer elected by it and may appoint or elect his successor.

            Section 12. The Board of Directors may designate an officer to be in
charge of such of the departments or division of the Company as it may deem
advisable.
<PAGE>   21
                                                                         Page 21


                                   ARTICLE III
                                   COMMITTEES

            Section 1.  Executive Committee

                        (A) The Executive Committee shall be composed of not
more than nine members who shall be selected by the Board of Directors from its
own members and who shall hold office during the pleasure of the Board.

                        (B) The Executive Committee shall have all the powers of
the Board of Directors when it is not in session to transact all business for
and in behalf of the Company that may be brought before it.

                        (C) The Executive Committee shall meet at the principal
office of the Company or elsewhere in its discretion at such times to be
determined by a majority of its members, or at the call of the Chairman of the
Executive Committee or at the call of the Chairman of the Board of Directors.
The majority of its members shall be necessary to constitute a quorum for the
transaction of business. Special meetings of the Executive Committee may be held
at any time when a quorum is present.

                        (D) Minutes of each meeting of the Executive Committee
shall be kept and submitted to the Board of Directors at its next meeting.

                        (E) The Executive Committee shall advise and superintend
all investments that may be made of the funds of the Company, and shall direct
the disposal of the same, in accordance with such rules and regulations as the
Board of Directors from time to time make.

                        (F) In the event of a state of disaster of sufficient
severity to prevent the conduct and management of the affairs and business of
the Company by its directors and officers as contemplated by these By-Laws any
two available members of the Executive Committee as constituted immediately
prior to such disaster shall constitute a quorum of that Committee for the full
conduct and management of the affairs and business of the Company in accordance
with the provisions of Article III of these By-Laws; and if less than three
members of the Trust Committee is constituted immediately prior to such disaster
shall be available for the transaction of its business, such Executive Committee
shall also be empowered to exercise all of the powers reserved to the Trust
Committee under Article III Section 2 hereof. In the event of the
unavailability, at such time, of a minimum of two members of such Executive
Committee, any three available directors shall constitute the Executive
Committee for the full conduct and management of the affairs and business of the
Company in accordance with the foregoing provisions of this Section. This By-Law
shall be subject to implementation by Resolutions of the Board of Directors
presently existing or hereafter passed from time to time for that purpose, and
any provisions of these By-Laws (other than this Section) and any resolutions
which are contrary to the provisions of this Section or to the provisions of any
such implementary Resolutions 
<PAGE>   22
                                                                         Page 22


shall be suspended during such a disaster period until it shall be determined by
any interim Executive Committee acting under this section that it shall be to
the advantage of the Company to resume the conduct and management of its affairs
and business under all of the other provisions of these By-Laws.

            Section 2.  Trust Committee

                        (A) The Trust Committee shall be composed of not more
than thirteen members who shall be selected by the Board of Directors, a
majority of whom shall be members of the Board of Directors and who shall hold
office during the pleasure of the Board.

                        (B) The Trust Committee shall have general supervision
over the Trust Department and the investment of trust funds, in all matters,
however, being subject to the approval of the Board of Directors.

                        (C) The Trust Committee shall meet at the principal
office of the Company or elsewhere in its discretion at such times to be
determined by a majority of its members or at the call of its chairman. A
majority of its members shall be necessary to constitute a quorum for the
transaction of business.

                        (D) Minutes of each meeting of the Trust Committee shall
be kept and promptly submitted to the Board of Directors.

                        (E) The Trust Committee shall have the power to appoint
Committees and/or designate officers or employees of the Company to whom
supervision over the investment of trust funds may be delegated when the Trust
Committee is not in session.

            Section 3.  Audit Committee

                        (A) The Audit Committee shall be composed of five
members who shall be selected by the Board of Directors from its own members,
none of whom shall be an officer of the Company, and shall hold office at the
pleasure of the Board.

                        (B) The Audit Committee shall have general supervision
over the Audit Division in all matters however subject to the approval of the
Board of Directors; it shall consider all matters brought to its attention by
the officer in charge of the Audit Division, review all reports of examination
of the Company made by any governmental agency or such independent auditor
employed for that purpose, and make such recommendations to the Board of
Directors with respect thereto or with respect to any other matters pertaining
to auditing the Company as it shall deem desirable.

                        (C) The Audit Committee shall meet whenever and wherever
the majority of its members shall deem it to be proper for the transaction of
its business, and a majority of its Committee shall constitute a quorum.
<PAGE>   23
                                                                         Page 23


            Section 4.  Compensation Committee

                        (A) The Compensation Committee shall be composed of not
more than five (5) members who shall be selected by the Board of Directors from
its own members who are not officers of the Company and who shall hold office
during the pleasure of the Board.

                        (B) The Compensation Committee shall in general advise
upon all matters of policy concerning the Company brought to its attention by
the management and from time to time review the management of the Company, major
organizational matters, including salaries and employee benefits and
specifically shall administer the Executive Incentive Compensation Plan.

                        (C) Meetings of the Compensation Committee may be called
at any time by the Chairman of the Compensation Committee, the Chairman of the
Board of Directors, or the President of the Company.

            Section 5.  Associate Directors

                        (A) Any person who has served as a director may be
elected by the Board of Directors as an associate director, to serve during the
pleasure of the Board.

                        (B) An associate director shall be entitled to attend
all directors meetings and participate in the discussion of all matters brought
to the Board, with the exception that he would have no right to vote. An
associate director will be eligible for appointment to Committees of the
Company, with the exception of the Executive Committee, Audit Committee and
Compensation Committee, which must be comprised solely of active directors.

            Section 6.  Absence or Disqualification of Any Member of a Committee

                        (A) In the absence or disqualification of any member of
any Committee created under Article III of the By-Laws of this Company, the
member or members thereof present at any meeting and not disqualified from
voting, whether or not he or they constitute a quorum, may unanimously appoint
another member of the Board of Directors to act at the meeting in the place of
any such absence or disqualified member.


                                   ARTICLE IV
                                    OFFICERS

            Section 1. The Chairman of the Board of Directors shall preside at
all meetings of the Board and shall have such further authority and powers and
shall perform such duties as the Board of Directors may from time to time confer
and direct. 
<PAGE>   24
                                                                         Page 24


He shall also exercise such powers and perform such duties as may from time to
time be agreed upon between himself and the President of the Company.

            Section 2. The Vice Chairman of the Board. The Vice Chairman of the
Board of Directors shall preside at all meetings of the Board of Directors at
which the Chairman of the Board shall not be present and shall have such further
authority and powers and shall perform such duties as the Board of Directors or
the Chairman of the Board may from time to time confer and direct.

            Section 3. The President shall have the powers and duties pertaining
to the office of the President conferred or imposed upon him by statute or
assigned to him by the Board of Directors in the absence of the Chairman of the
Board the President shall have the powers and duties of the Chairman of the
Board.

            Section 4. The Chairman of the Board of Directors or the President
as designated by the Board of Directors, shall carry into effect all legal
directions of the Executive Committee and of the Board of Directors, and shall
at all times exercise general supervision over the interest, affairs and
operations of the Company and perform all duties incident to his office.

            Section 5. There may be one or more Vice Presidents, however
denominated by the Board of Directors, who may at any time perform all the
duties of the Chairman of the Board of Directors and/or the President and such
other powers and duties as may from time to time be assigned to them by the
Board of Directors, the Executive Committee, the Chairman of the Board or the
President and by the officer in charge of the department or division to which
they are assigned.

            Section 6. The Secretary shall attend to the giving of notice of
meetings of the stockholders and the Board of Directors, as well as the
Committees thereof, to the keeping of accurate minutes of all such meetings and
to recording the same in the minute books of the Company. In addition to the
other notice requirements of these By-Laws and as may be practicable under the
circumstances, all such notices shall be in writing and mailed well in advance
of the scheduled date of any other meeting. He shall have custody of the
corporate seal and shall affix the same to any documents requiring such
corporate seal and to attest the same.

            Section 7. The Treasurer shall have general supervision over all
assets and liabilities of the Company. He shall be custodian of and responsible
for all monies, funds and valuables of the Company and for the keeping of proper
records of the evidence of property or indebtedness and of all the transactions
of the Company. He shall have general supervision of the expenditures of the
Company and shall report to the Board of Directors at each regular meeting of
the condition of the Company, and perform such other duties as may be assigned
to him from time to time by the Board of Directors of the Executive Committee.

            Section 8. There may be a Controller who shall exercise general
supervision 
<PAGE>   25
                                                                         Page 25


over the internal operations of the Company, including accounting, and shall
render to the Board of Directors at appropriate times a report relating to the
general condition and internal operations of the Company.

            There may be one or more subordinate accounting or controller
officers however denominated, who may perform the duties of the Controller and
such duties as may be prescribed by the Controller.

            Section 9. The officer designated by the Board of Directors to be in
charge of the Audit Division of the Company with such title as the Board of
Directors shall prescribe, shall report to and be directly responsible only to
the Board of Directors.

            There shall be an Auditor and there may be one or more Audit
Officers, however denominated, who may perform all the duties of the Auditor and
such duties as may be prescribed by the officer in charge of the Audit Division.

            Section 10. There may be one or more officers, subordinate in rank
to all Vice Presidents with such functional titles as shall be determined from
time to time by the Board of Directors, who shall ex officio hold the office
Assistant Secretary of this Company and who may perform such duties as may be
prescribed by the officer in charge of the department or division to whom they
are assigned.

            Section 11. The powers and duties of all other officers of the
Company shall be those usually pertaining to their respective offices, subject
to the direction of the Board of Directors, the Executive Committee, Chairman of
the Board of Directors or the President and the officer in charge of the
department or division to which they are assigned.


                                    ARTICLE V
                          STOCK AND STOCK CERTIFICATES

            Section 1. Shares of stock shall be transferrable on the books of
the Company and a transfer book shall be kept in which all transfers of stock
shall be recorded.

            Section 2. Certificate of stock shall bear the signature of the
President or any Vice President, however denominated by the Board of Directors
and countersigned by the Secretary or Treasurer or an Assistant Secretary, and
the seal of the corporation shall be engraved thereon. Each certificate shall
recite that the stock represented thereby is transferrable only upon the books
of the Company by the holder thereof or his attorney, upon surrender of the
certificate properly endorsed. Any certificate of stock surrendered to the
Company shall be cancelled at the time of transfer, and before a new certificate
or certificates shall be issued in lieu thereof. Duplicate certificates of stock
shall be issued only upon giving such security as may be satisfactory to the
Board of Directors or the Executive Committee.
<PAGE>   26
                                                                         Page 26


            Section 3. The Board of Directors of the Company is authorized to
fix in advance a record date for the determination of the stockholders entitled
to notice of, and to vote at, any meeting of stockholders and any adjournment
thereof, or entitled to receive payment of any dividend, or to any allotment or
rights, or to exercise any rights in respect of any change, conversion or
exchange of capital stock, or in connection with obtaining the consent of
stockholders for any purpose, which record date shall not be more than 60 nor
less than 10 days proceeding the date of any meeting of stockholders or the date
for the payment of any dividend, or the date for the allotment of rights, or the
date when any change or conversion or exchange of capital stock shall go into
effect, or a date in connection with obtaining such consent.


                                   ARTICLE VI
                                      SEAL

            Section 1. The corporate seal of the Company shall be in the
following form:

                        Between two concentric circles the words "Wilmington
                        Trust Company" within the inner circle the words
                        "Wilmington, Delaware."


                                   ARTICLE VII
                                   FISCAL YEAR

            Section 1. The fiscal year of the Company shall be the calendar
year.
<PAGE>   27
                                                                         Page 27


                                  ARTICLE VIII
                     EXECUTION OF INSTRUMENTS OF THE COMPANY

            Section 1. The Chairman of the Board, the President or any Vice
President, however denominated by the Board of Directors, shall have full power
and authority to enter into, make, sign, execute, acknowledge and/or deliver and
the Secretary or any Assistant Secretary shall have full power and authority to
attest and affix the corporate seal of the Company to any and all deeds,
conveyances, assignments, releases, contracts, agreements, bonds, notes,
mortgages and all other instruments incident to the business of this Company or
in acting as executor, administrator, guardian, trustee, agent or in any other
fiduciary or representative capacity by any and every method of appointment or
by whatever person, corporation, court officer or authority in the State of
Delaware, or elsewhere, without any specific authority, ratification, approval
or confirmation by the Board of Directors or the Executive Committee, and any
and all such instruments shall have the same force and validity as though
expressly authorized by the Board of Directors and/or the Executive Committee.


                                   ARTICLE IX
               COMPENSATION OF DIRECTORS AND MEMBERS OF COMMITTEES

            Section 1. Directors and associate directors of the Company, other
than salaried officers of the Company, shall be paid such reasonable honoraria
or fees for attending meetings of the Board of Directors as the Board of
Directors may from time to time determine. Directors and associate directors who
serve as members of committees, other than salaried employees of the Company,
shall be paid such reasonable honoraria or fees for services as members of
committees as the Board of Directors shall from time to time determine and
directors and associate directors may be employed by the Company for such
special services as the Board of Directors may from time to time determine and
shall be paid for such special services so performed reasonable compensation as
may be determined by the Board of Directors.


                                    ARTICLE X
                                 INDEMNIFICATION

            Section 1. (A) The Corporation shall indemnify and hold harmless, to
the fullest extent permitted by applicable law as it presently exists or may
hereafter be amended, any person who was or is made or is threatened to be made
a party or is otherwise involved in any action, suit or proceeding, whether
civil, criminal, administrative or investigative (a "proceeding") by reason of
the fact that he, or a person for whom he is the legal representative, is or was
a director, officer, employee or agent of the Corporation or is or was serving
at the request of the Corporation as a director, officer, employee, fiduciary or
agent of another corporation or of a partnership, joint venture, trust,
enterprise or non-profit entity, including service with respect to employee
<PAGE>   28
                                                                         Page 28


benefit plans, against all liability and loss suffered and expenses reasonably
incurred by such person. The Corporation shall indemnify a person in connection
with a proceeding initiated by such person only if the proceeding was authorized
by the Board of Directors of the Corporation.

                        (B) The Corporation shall pay the expenses incurred in
defending any proceeding in advance of its final disposition, provided, however,
that the payment of expenses incurred by a Director officer in his capacity as a
Director or officer in advance of the final disposition of the proceeding shall
be made only upon receipt of an undertaking by the Director or officer to repay
all amounts advanced if it should be ultimately determined that the Director or
officer is not entitled to be indemnified under this Article or otherwise.

                        (C) If a claim for indemnification or payment of
expenses, under this Article X is not paid in full within ninety days after a
written claim therefor has been received by the Corporation the claimant may
file suit to recover the unpaid amount of such claim and, if successful in whole
or in part, shall be entitled to be paid the expense of prosecuting such claim.
In any such action the Corporation shall have the burden of proving that the
claimant was not entitled to the requested indemnification of payment of
expenses under applicable law.

                        (D) The rights conferred on any person by this Article X
shall not be exclusive of any other rights which such person may have or
hereafter acquire under any statute, provision of the Charter or Act of
Incorporation, these By-Laws, agreement, vote of stockholders or disinterested
Directors or otherwise.

                        (E) Any repeal or modification of the foregoing
provisions of this Article X shall not adversely affect any right or protection
hereunder of any person in respect of any act or omission occurring prior to the
time of such repeal or modification.


                                   ARTICLE XI
                            AMENDMENTS TO THE BY-LAWS

            Section 1. These By-Laws may be altered, amended or repealed, in
whole or in part, and any new By-Law or By-Laws adopted at any regular or
special meeting of the Board of Directors by a vote of the majority of all the
members of the Board of Directors then in office.
<PAGE>   29
                                                                         Page 29


                                    EXHIBIT C




                             SECTION 321(b) CONSENT


            Pursuant to Section 321(b) of the Trust Indenture Act of 1939, as
amended, Wilmington Trust Company hereby consents that reports of examinations
by Federal, State, Territorial or District authorities may be furnished by such
authorities to the Securities and Exchange Commission upon requests therefor.



                                             WILMINGTON TRUST COMPANY


Dated: December 10, 1998                     By:/s/ James P. Lawler           
                                                -------------------
                                             Name:  James P. Lawler
                                             Title: Vice President
<PAGE>   30
                                                                         Page 30


                                    EXHIBIT D



                                     NOTICE


            This form is intended to assist state nonmember banks and savings
            banks with state publication requirements. It has not been approved
            by any state banking authorities. Refer to your appropriate state
            banking authorities for your state publication requirements.



R E P O R T   O F   C O N D I T I O N

Consolidating domestic subsidiaries of the

           WILMINGTON TRUST COMPANY        of     WILMINGTON    
                 Name of Bank                        City

in the State of DELAWARE, at the close of business on September 30, 1998.



<TABLE>
<CAPTION>
ASSETS
                                                                                 Thousands of dollars
<S>                                                                              <C>    
Cash and balances due from depository institutions:
Noninterest-bearing balances and currency and coins ......................              180,755
Interest-bearing balances ................................................                    0
Held-to-maturity securities ..............................................              148,529
Available-for-sale securities ............................................            1,216,482
Federal funds sold and securities purchased under agreements to resell ...              203,500
Loans and lease financing receivables:                                              
Loans and leases, net of unearned income .................................            3,951,771
LESS:  Allowance for loan and lease losses ...............................               64,835
LESS:  Allocated transfer risk reserve ...................................                    0
Loans and leases, net of unearned income, allowance, and reserve .........            3,886,936
Assets held in trading accounts ..........................................                    0
Premises and fixed assets (including capitalized leases) .................              137,819
Other real estate owned ..................................................                1,847
Investments in unconsolidated subsidiaries and associated companies ......                  997
Customers' liability to this bank on acceptances outstanding .............                    0
Intangible assets ........................................................                3,105
Other assets .............................................................               82,400
Total assets .............................................................            5,862,370
</TABLE>


CONTINUED ON NEXT PAGE
<PAGE>   31
                                                                         Page 31


<TABLE>
<S>                                                                                  <C>      
LIABILITIES

Deposits:
In domestic offices ..........................................................       4,338,785
     Noninterest-bearing .....................................................         792,528
     Interest-bearing ........................................................       3,546,257
Federal funds purchased and Securities sold under agreements to repurchase ...         249,670
Demand notes issued to the U.S. Treasury .....................................          74,347
Trading liabilities (from Schedule RC-D) .....................................               0
Other borrowed money: ........................................................         ///////
     With original maturity of one year or less ..............................         576,507
     With original maturity of more than one year ............................          43,000
Bank's liability on acceptances executed and outstanding .....................               0
Subordinated notes and debentures ............................................               0
Other liabilities (from Schedule RC-G) .......................................         104,687
Total liabilities ............................................................       5,386,996


EQUITY CAPITAL

Perpetual preferred stock and related surplus ................................               0
Common Stock .................................................................             500
Surplus (exclude all surplus related to preferred stock) .....................          62,118
Undivided profits and capital reserves .......................................         399,222
Net unrealized holding gains (losses) on available-for-sale securities .......          13,534
Total equity capital .........................................................         475,374
Total liabilities, limited-life preferred stock, and equity capital ..........       5,862,370
</TABLE>

<PAGE>   1
                                                                    EXHIBIT 25.3




                                                                Registration No.



                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                    FORM T-1

         STATEMENT OF ELIGIBILITY UNDER THE TRUST INDENTURE ACT OF 1939
                  OF A CORPORATION DESIGNATED TO ACT AS TRUSTEE

CHECK IF AN APPLICATION TO DETERMINE ELIGIBILITY OF A TRUSTEE PURSUANT TO
SECTION 305(b)(2) _____      

                            WILMINGTON TRUST COMPANY
               (Exact name of trustee as specified in its charter)


        Delaware                                         51-0055023
(State of incorporation)                    (I.R.S. employer identification no.)

                               Rodney Square North
                            1100 North Market Street
                           Wilmington, Delaware 19890
                    (Address of principal executive offices)

                               Cynthia L. Corliss
                        Vice President and Trust Counsel
                            Wilmington Trust Company
                               Rodney Square North
                           Wilmington, Delaware 19890
                                 (302) 651-8516
            (Name, address and telephone number of agent for service)

                           AMERICA WEST AIRLINES, INC.

               (Exact name of obligor as specified in its charter)

        Delaware                                         86-0418245
(State of incorporation)                    (I.R.S. employer identification no.)

4000 E. Sky Harbor Boulevard
      Phoenix, Arizona                                   85034-3899
(Address of principal executive offices)                 (Zip Code)


                    Pass Through Certificates, Series 1998-1C
<PAGE>   2
                                                                          Page 2


                       (Title of the indenture securities)
<PAGE>   3
                                                                          Page 3


ITEM 1.     GENERAL INFORMATION.

                    Furnish the following information as to the trustee:

            (a)     Name and address of each examining or supervising authority
                    to which it is subject.

                    Federal Deposit Insurance Co.        State Bank Commissioner
                    Five Penn Center                        Dover, Delaware
                    Suite #2901
                    Philadelphia, PA

            (b)     Whether it is authorized to exercise corporate trust powers.

                    The trustee is authorized to exercise corporate trust
                    powers.

ITEM 2.     AFFILIATIONS WITH THE OBLIGOR.

                    If the obligor is an affiliate of the trustee, describe each
            affiliation:

                    Based upon an examination of the books and records of the
            trustee and upon information furnished by the obligor, the obligor
            is not an affiliate of the trustee.

ITEM 3.  LIST OF EXHIBITS.

                 List below all exhibits filed as part of this Statement of
Eligibility and Qualification.

            A.      Copy of the Charter of Wilmington Trust Company, which
                    includes the certificate of authority of Wilmington Trust
                    Company to commence business and the authorization of
                    Wilmington Trust Company to exercise corporate trust powers.

            B.      Copy of By-Laws of Wilmington Trust Company.

            C.      Consent of Wilmington Trust Company required by Section
                    321(b) of Trust Indenture Act.

            D.      Copy of most recent Report of Condition of Wilmington Trust
                    Company.

            Pursuant to the requirements of the Trust Indenture Act of 1939, as
amended, the trustee, Wilmington Trust Company, a corporation organized and
existing under the laws of Delaware, has duly caused this Statement of
Eligibility to be signed on its behalf by the undersigned, thereunto duly
authorized, all in the City of Wilmington and State of Delaware on the 10th day
of December, 1998.


                                        WILMINGTON TRUST COMPANY
[SEAL]

Attest:/s/ Christopher L. Kaiser        By:/s/ James P. Lawler            
       -------------------------           -------------------
       Assistant Secretary              Name:  James P. Lawler
                                        Title:  Vice President
<PAGE>   4
                                                                          Page 4


                                    EXHIBIT A

                                 AMENDED CHARTER

                            WILMINGTON TRUST COMPANY

                              WILMINGTON, DELAWARE

                           AS EXISTING ON MAY 9, 1987
<PAGE>   5
                                                                          Page 5


                                 AMENDED CHARTER

                                       OR

                              ACT OF INCORPORATION

                                       OF

                            WILMINGTON TRUST COMPANY

            WILMINGTON TRUST COMPANY, originally incorporated by an Act of the
General Assembly of the State of Delaware, entitled "An Act to Incorporate the
Delaware Guarantee and Trust Company", approved March 2, A.D. 1901, and the name
of which company was changed to "WILMINGTON TRUST COMPANY" by an amendment filed
in the Office of the Secretary of State on March 18, A.D. 1903, and the Charter
or Act of Incorporation of which company has been from time to time amended and
changed by merger agreements pursuant to the corporation law for state banks and
trust companies of the State of Delaware, does hereby alter and amend its
Charter or Act of Incorporation so that the same as so altered and amended shall
in its entirety read as follows:

            FIRST: - The name of this corporation is WILMINGTON TRUST COMPANY.

            SECOND: - The location of its principal office in the State of
            Delaware is at Rodney Square North, in the City of Wilmington,
            County of New Castle; the name of its resident agent is WILMINGTON
            TRUST COMPANY whose address is Rodney Square North, in said City. In
            addition to such principal office, the said corporation maintains
            and operates branch offices in the City of Newark, New Castle
            County, Delaware, the Town of Newport, New Castle County, Delaware,
            at Claymont, New Castle County, Delaware, at Greenville, New Castle
            County Delaware, and at Milford Cross Roads, New Castle County,
            Delaware, and shall be empowered to open, maintain and operate
            branch offices at Ninth and Shipley Streets, 418 Delaware Avenue,
            2120 Market Street, and 3605 Market Street, all in the City of
            Wilmington, New Castle County, Delaware, and such other branch
            offices or places of business as may be authorized from time to time
            by the agency or agencies of the government of the State of Delaware
            empowered to confer such authority.

            THIRD: - (a) The nature of the business and the objects and purposes
            proposed to be transacted, promoted or carried on by this
            Corporation are to do any or all of the things herein mentioned as
            fully and to the same extent as natural persons might or could do
            and in any part of the world, viz.:

                    (1) To sue and be sued, complain and defend in any Court of
                    law or equity and to make and use a common seal, and alter
                    the seal at pleasure, to hold, purchase, convey, mortgage or
                    otherwise deal in real
<PAGE>   6
                                                                          Page 6


                    and personal estate and property, and to appoint such
                    officers and agents as the business of the Corporation shall
                    require, to make by-laws not inconsistent with the
                    Constitution or laws of the United States or of this State,
                    to discount bills, notes or other evidences of debt, to
                    receive deposits of money, or securities for money, to buy
                    gold and silver bullion and foreign coins, to buy and sell
                    bills of exchange, and generally to use, exercise and enjoy
                    all the powers, rights, privileges and franchises incident
                    to a corporation which are proper or necessary for the
                    transaction of the business of the Corporation hereby
                    created.

                    (2) To insure titles to real and personal property, or any
                    estate or interests therein, and to guarantee the holder of
                    such property, real or personal, against any claim or
                    claims, adverse to his interest therein, and to prepare and
                    give certificates of title for any lands or premises in the
                    State of Delaware, or elsewhere.

                    (3) To act as factor, agent, broker or attorney in the
                    receipt, collection, custody, investment and management of
                    funds, and the purchase, sale, management and disposal of
                    property of all descriptions, and to prepare and execute all
                    papers which may be necessary or proper in such business.

                    (4) To prepare and draw agreements, contracts, deeds,
                    leases, conveyances, mortgages, bonds and legal papers of
                    every description, and to carry on the business of
                    conveyancing in all its branches.

                    (5) To receive upon deposit for safekeeping money, jewelry,
                    plate, deeds, bonds and any and all other personal property
                    of every sort and kind, from executors, administrators,
                    guardians, public officers, courts, receivers, assignees,
                    trustees, and from all fiduciaries, and from all other
                    persons and individuals, and from all corporations whether
                    state, municipal, corporate or private, and to rent boxes,
                    safes, vaults and other receptacles for such property.

                    (6) To act as agent or otherwise for the purpose of
                    registering, issuing, certificating, countersigning,
                    transferring or underwriting the stock, bonds or other
                    obligations of any corporation, association, state or
                    municipality, and may receive and manage any sinking fund
                    therefor on such terms as may be agreed upon between the two
                    parties, and in like manner may act as Treasurer of any
                    corporation or municipality.

                    (7) To act as Trustee under any deed of trust, mortgage,
                    bond or other instrument issued by any state, municipality,
                    body politic, corporation, association or person, either
                    alone or in conjunction with any other person or persons,
                    corporation or corporations.
<PAGE>   7
                                                                          Page 7


                    (8) To guarantee the validity, performance or effect of any
                    contract or agreement, and the fidelity of persons holding
                    places of responsibility or trust; to become surety for any
                    person, or persons, for the faithful performance of any
                    trust, office, duty, contract or agreement, either by itself
                    or in conjunction with any other person, or persons,
                    corporation, or corporations, or in like manner become
                    surety upon any bond, recognizance, obligation, judgment,
                    suit, order, or decree to be entered in any court of record
                    within the State of Delaware or elsewhere, or which may now
                    or hereafter be required by any law, judge, officer or court
                    in the State of Delaware or elsewhere.

                    (9) To act by any and every method of appointment as
                    trustee, trustee in bankruptcy, receiver, assignee, assignee
                    in bankruptcy, executor, administrator, guardian, bailee, or
                    in any other trust capacity in the receiving, holding,
                    managing, and disposing of any and all estates and property,
                    real, personal or mixed, and to be appointed as such
                    trustee, trustee in bankruptcy, receiver, assignee, assignee
                    in bankruptcy, executor, administrator, guardian or bailee
                    by any persons, corporations, court, officer, or authority,
                    in the State of Delaware or elsewhere; and whenever this
                    Corporation is so appointed by any person, corporation,
                    court, officer or authority such trustee, trustee in
                    bankruptcy, receiver, assignee, assignee in bankruptcy,
                    executor, administrator, guardian, bailee, or in any other
                    trust capacity, it shall not be required to give bond with
                    surety, but its capital stock shall be taken and held as
                    security for the performance of the duties devolving upon it
                    by such appointment.

                    (10) And for its care, management and trouble, and the
                    exercise of any of its powers hereby given, or for the
                    performance of any of the duties which it may undertake or
                    be called upon to perform, or for the assumption of any
                    responsibility the said Corporation may be entitled to
                    receive a proper compensation.

                    (11) To purchase, receive, hold and own bonds, mortgages,
                    debentures, shares of capital stock, and other securities,
                    obligations, contracts and evidences of indebtedness, of any
                    private, public or municipal corporation within and without
                    the State of Delaware, or of the Government of the United
                    States, or of any state, territory, colony, or possession
                    thereof, or of any foreign government or country; to
                    receive, collect, receipt for, and dispose of interest,
                    dividends and income upon and from any of the bonds,
                    mortgages, debentures, notes, shares of capital stock,
                    securities, obligations, contracts, evidences of
                    indebtedness and other property held and owned by it, and to
                    exercise in respect of all such bonds, mortgages,
                    debentures, notes, shares of capital stock, securities,
                    obligations, contracts, evidences of indebtedness and other
                    property, any and all the rights, powers and privileges of
                    individual owners thereof, including the right to vote
                    thereon; 
<PAGE>   8
                                                                          Page 8


                    to invest and deal in and with any of the moneys of the
                    Corporation upon such securities and in such manner as it
                    may think fit and proper, and from time to time to vary or
                    realize such investments; to issue bonds and secure the same
                    by pledges or deeds of trust or mortgages of or upon the
                    whole or any part of the property held or owned by the
                    Corporation, and to sell and pledge such bonds, as and when
                    the Board of Directors shall determine, and in the promotion
                    of its said corporate business of investment and to the
                    extent authorized by law, to lease, purchase, hold, sell,
                    assign, transfer, pledge, mortgage and convey real and
                    personal property of any name and nature and any estate or
                    interest therein.

            (b) In furtherance of, and not in limitation, of the powers
            conferred by the laws of the State of Delaware, it is hereby
            expressly provided that the said Corporation shall also have the
            following powers:

                    (1) To do any or all of the things herein set forth, to the
                    same extent as natural persons might or could do, and in any
                    part of the world.

                    (2) To acquire the good will, rights, property and
                    franchises and to undertake the whole or any part of the
                    assets and liabilities of any person, firm, association or
                    corporation, and to pay for the same in cash, stock of this
                    Corporation, bonds or otherwise; to hold or in any manner to
                    dispose of the whole or any part of the property so
                    purchased; to conduct in any lawful manner the whole or any
                    part of any business so acquired, and to exercise all the
                    powers necessary or convenient in and about the conduct and
                    management of such business.

                    (3) To take, hold, own, deal in, mortgage or otherwise lien,
                    and to lease, sell, exchange, transfer, or in any manner
                    whatever dispose of property, real, personal or mixed,
                    wherever situated.

                    (4) To enter into, make, perform and carry out contracts of
                    every kind with any person, firm, association or
                    corporation, and, without limit as to amount, to draw, make,
                    accept, endorse, discount, execute and issue promissory
                    notes, drafts, bills of exchange, warrants, bonds,
                    debentures, and other negotiable or transferable
                    instruments.

                    (5) To have one or more offices, to carry on all or any of
                    its operations and businesses, without restriction to the
                    same extent as natural persons might or could do, to
                    purchase or otherwise acquire, to hold, own, to mortgage,
                    sell, convey or otherwise dispose of, real and personal
                    property, of every class and description, in any State,
                    District, Territory or Colony of the United States, and in
                    any foreign country or place.

                    (6) It is the intention that the objects, purposes and
                    powers specified and clauses contained in this paragraph
                    shall (except where otherwise 
<PAGE>   9
                                                                          Page 9


                    expressed in said paragraph) be nowise limited or restricted
                    by reference to or inference from the terms of any other
                    clause of this or any other paragraph in this charter, but
                    that the objects, purposes and powers specified in each of
                    the clauses of this paragraph shall be regarded as
                    independent objects, purposes and powers.

            FOURTH: - (a) The total number of shares of all classes of stock
            which the Corporation shall have authority to issue is forty-one
            million (41,000,000) shares, consisting of:

                    (1) One million (1,000,000) shares of Preferred stock, par
                    value $10.00 per share (hereinafter referred to as
                    "Preferred Stock"); and

                    (2) Forty million (40,000,000) shares of Common Stock, par
                    value $1.00 per share (hereinafter referred to as "Common
                    Stock").

            (b) Shares of Preferred Stock may be issued from time to time in one
            or more series as may from time to time be determined by the Board
            of Directors each of said series to be distinctly designated. All
            shares of any one series of Preferred Stock shall be alike in every
            particular, except that there may be different dates from which
            dividends, if any, thereon shall be cumulative, if made cumulative.
            The voting powers and the preferences and relative, participating,
            optional and other special rights of each such series, and the
            qualifications, limitations or restrictions thereof, if any, may
            differ from those of any and all other series at any time
            outstanding; and, subject to the provisions of subparagraph 1 of
            Paragraph (c) of this Article FOURTH, the Board of Directors of the
            Corporation is hereby expressly granted authority to fix by
            resolution or resolutions adopted prior to the issuance of any
            shares of a particular series of Preferred Stock, the voting powers
            and the designations, preferences and relative, optional and other
            special rights, and the qualifications, limitations and restrictions
            of such series, including, but without limiting the generality of
            the foregoing, the following:

                    (1) The distinctive designation of, and the number of shares
                    of Preferred Stock which shall constitute such series, which
                    number may be increased (except where otherwise provided by
                    the Board of Directors) or decreased (but not below the
                    number of shares thereof then outstanding) from time to time
                    by like action of the Board of Directors;

                    (2) The rate and times at which, and the terms and
                    conditions on which, dividends, if any, on Preferred Stock
                    of such series shall be paid, the extent of the preference
                    or relation, if any, of such dividends to the dividends
                    payable on any other class or classes, or series of the same
                    or other class of stock and whether such dividends shall be
                    cumulative or non-cumulative;
<PAGE>   10
                                                                         Page 10


                    (3) The right, if any, of the holders of Preferred Stock of
                    such series to convert the same into or exchange the same
                    for, shares of any other class or classes or of any series
                    of the same or any other class or classes of stock of the
                    Corporation and the terms and conditions of such conversion
                    or exchange;

                    (4) Whether or not Preferred Stock of such series shall be
                    subject to redemption, and the redemption price or prices
                    and the time or times at which, and the terms and conditions
                    on which, Preferred Stock of such series may be redeemed.

                    (5) The rights, if any, of the holders of Preferred Stock of
                    such series upon the voluntary or involuntary liquidation,
                    merger, consolidation, distribution or sale of assets,
                    dissolution or winding-up, of the Corporation.

                    (6) The terms of the sinking fund or redemption or purchase
                    account, if any, to be provided for the Preferred Stock of
                    such series; and

                    (7) The voting powers, if any, of the holders of such series
                    of Preferred Stock which may, without limiting the
                    generality of the foregoing include the right, voting as a
                    series or by itself or together with other series of
                    Preferred Stock or all series of Preferred Stock as a class,
                    to elect one or more directors of the Corporation if there
                    shall have been a default in the payment of dividends on any
                    one or more series of Preferred Stock or under such
                    circumstances and on such conditions as the Board of
                    Directors may determine.

            (c) (1) After the requirements with respect to preferential
            dividends on the Preferred Stock (fixed in accordance with the
            provisions of section (b) of this Article FOURTH), if any, shall
            have been met and after the Corporation shall have complied with all
            the requirements, if any, with respect to the setting aside of sums
            as sinking funds or redemption or purchase accounts (fixed in
            accordance with the provisions of section (b) of this Article
            FOURTH), and subject further to any conditions which may be fixed in
            accordance with the provisions of section (b) of this Article
            FOURTH, then and not otherwise the holders of Common Stock shall be
            entitled to receive such dividends as may be declared from time to
            time by the Board of Directors.

                    (2) After distribution in full of the preferential amount,
                    if any, (fixed in accordance with the provisions of section
                    (b) of this Article FOURTH), to be distributed to the
                    holders of Preferred Stock in the event of voluntary or
                    involuntary liquidation, distribution or sale of assets,
                    dissolution or winding-up, of the Corporation, the holders
                    of the Common Stock shall be entitled to receive all of the
                    remaining assets of the Corporation, tangible and
                    intangible, of whatever kind available for distribution to
<PAGE>   11
                                                                         Page 11


                    stockholders ratably in proportion to the number of shares
                    of Common Stock held by them respectively.

                    (3) Except as may otherwise be required by law or by the
                    provisions of such resolution or resolutions as may be
                    adopted by the Board of Directors pursuant to section (b) of
                    this Article FOURTH, each holder of Common Stock shall have
                    one vote in respect of each share of Common Stock held on
                    all matters voted upon by the stockholders.

            (d) No holder of any of the shares of any class or series of stock
            or of options, warrants or other rights to purchase shares of any
            class or series of stock or of other securities of the Corporation
            shall have any preemptive right to purchase or subscribe for any
            unissued stock of any class or series or any additional shares of
            any class or series to be issued by reason of any increase of the
            authorized capital stock of the Corporation of any class or series,
            or bonds, certificates of indebtedness, debentures or other
            securities convertible into or exchangeable for stock of the
            Corporation of any class or series, or carrying any right to
            purchase stock of any class or series, but any such unissued stock,
            additional authorized issue of shares of any class or series of
            stock or securities convertible into or exchangeable for stock, or
            carrying any right to purchase stock, may be issued and disposed of
            pursuant to resolution of the Board of Directors to such persons,
            firms, corporations or associations, whether such holders or others,
            and upon such terms as may be deemed advisable by the Board of
            Directors in the exercise of its sole discretion.

            (e) The relative powers, preferences and rights of each series of
            Preferred Stock in relation to the relative powers, preferences and
            rights of each other series of Preferred Stock shall, in each case,
            be as fixed from time to time by the Board of Directors in the
            resolution or resolutions adopted pursuant to authority granted in
            section (b) of this Article FOURTH and the consent, by class or
            series vote or otherwise, of the holders of such of the series of
            Preferred Stock as are from time to time outstanding shall not be
            required for the issuance by the Board of Directors of any other
            series of Preferred Stock whether or not the powers, preferences and
            rights of such other series shall be fixed by the Board of Directors
            as senior to, or on a parity with, the powers, preferences and
            rights of such outstanding series, or any of them; provided,
            however, that the Board of Directors may provide in the resolution
            or resolutions as to any series of Preferred Stock adopted pursuant
            to section (b) of this Article FOURTH that the consent of the
            holders of a majority (or such greater proportion as shall be
            therein fixed) of the outstanding shares of such series voting
            thereon shall be required for the issuance of any or all other
            series of Preferred Stock.

            (f) Subject to the provisions of section (e), shares of any series
            of Preferred Stock may be issued from time to time as the Board of
            Directors of the Corporation shall determine and on such terms and
            for such consideration as 
<PAGE>   12
                                                                         Page 12


            shall be fixed by the Board of Directors.

            (g) Shares of Common Stock may be issued from time to time as the
            Board of Directors of the Corporation shall determine and on such
            terms and for such consideration as shall be fixed by the Board of
            Directors.

            (h) The authorized amount of shares of Common Stock and of Preferred
            Stock may, without a class or series vote, be increased or decreased
            from time to time by the affirmative vote of the holders of a
            majority of the stock of the Corporation entitled to vote thereon.

            FIFTH: - (a) The business and affairs of the Corporation shall be
            conducted and managed by a Board of Directors. The number of
            directors constituting the entire Board shall be not less than five
            nor more than twenty-five as fixed from time to time by vote of a
            majority of the whole Board, provided, however, that the number of
            directors shall not be reduced so as to shorten the term of any
            director at the time in office, and provided further, that the
            number of directors constituting the whole Board shall be
            twenty-four until otherwise fixed by a majority of the whole Board.

            (b) The Board of Directors shall be divided into three classes, as
            nearly equal in number as the then total number of directors
            constituting the whole Board permits, with the term of office of one
            class expiring each year. At the annual meeting of stockholders in
            1982, directors of the first class shall be elected to hold office
            for a term expiring at the next succeeding annual meeting, directors
            of the second class shall be elected to hold office for a term
            expiring at the second succeeding annual meeting and directors of
            the third class shall be elected to hold office for a term expiring
            at the third succeeding annual meeting. Any vacancies in the Board
            of Directors for any reason, and any newly created directorships
            resulting from any increase in the directors, may be filled by the
            Board of Directors, acting by a majority of the directors then in
            office, although less than a quorum, and any directors so chosen
            shall hold office until the next annual election of directors. At
            such election, the stockholders shall elect a successor to such
            director to hold office until the next election of the class for
            which such director shall have been chosen and until his successor
            shall be elected and qualified. No decrease in the number of
            directors shall shorten the term of any incumbent director.

            (c) Notwithstanding any other provisions of this Charter or Act of
            Incorporation or the By-Laws of the Corporation (and notwithstanding
            the fact that some lesser percentage may be specified by law, this
            Charter or Act of Incorporation or the By-Laws of the Corporation),
            any director or the entire Board of Directors of the Corporation may
            be removed at any time without cause, but only by the affirmative
            vote of the holders of two-thirds or more of the outstanding shares
            of capital stock of the Corporation entitled to vote generally in
            the election of directors (considered for this purpose as one class)
            cast at a 
<PAGE>   13
                                                                         Page 13


            meeting of the stockholders called for that purpose.

            (d) Nominations for the election of directors may be made by the
            Board of Directors or by any stockholder entitled to vote for the
            election of directors. Such nominations shall be made by notice in
            writing, delivered or mailed by first class United States mail,
            postage prepaid, to the Secretary of the Corporation not less than
            14 days nor more than 50 days prior to any meeting of the
            stockholders called for the election of directors; provided,
            however, that if less than 21 days' notice of the meeting is given
            to stockholders, such written notice shall be delivered or mailed,
            as prescribed, to the Secretary of the Corporation not later than
            the close of the seventh day following the day on which notice of
            the meeting was mailed to stockholders. Notice of nominations which
            are proposed by the Board of Directors shall be given by the
            Chairman on behalf of the Board.

            (e) Each notice under subsection (d) shall set forth (i) the name,
            age, business address and, if known, residence address of each
            nominee proposed in such notice, (ii) the principal occupation or
            employment of such nominee and (iii) the number of shares of stock
            of the Corporation which are beneficially owned by each such
            nominee.

            (f) The Chairman of the meeting may, if the facts warrant, determine
            and declare to the meeting that a nomination was not made in
            accordance with the foregoing procedure, and if he should so
            determine, he shall so declare to the meeting and the defective
            nomination shall be disregarded.

            (g) No action required to be taken or which may be taken at any
            annual or special meeting of stockholders of the Corporation may be
            taken without a meeting, and the power of stockholders to consent in
            writing, without a meeting, to the taking of any action is
            specifically denied.

            SIXTH: - The Directors shall choose such officers, agent and
            servants as may be provided in the By-Laws as they may from time to
            time find necessary or proper.

            SEVENTH: - The Corporation hereby created is hereby given the same
            powers, rights and privileges as may be conferred upon corporations
            organized under the Act entitled "An Act Providing a General
            Corporation Law", approved March 10, 1899, as from time to time
            amended.

            EIGHTH: - This Act shall be deemed and taken to be a private Act.

            NINTH: - This Corporation is to have perpetual existence.

            TENTH: - The Board of Directors, by resolution passed by a majority
            of the whole Board, may designate any of their number to constitute
            an Executive 
<PAGE>   14
                                    Page 14


            Committee, which Committee, to the extent provided in said
            resolution, or in the By-Laws of the Company, shall have and may
            exercise all of the powers of the Board of Directors in the
            management of the business and affairs of the Corporation, and shall
            have power to authorize the seal of the Corporation to be affixed to
            all papers which may require it.

            ELEVENTH: - The private property of the stockholders shall not be
            liable for the payment of corporate debts to any extent whatever.

            TWELFTH: - The Corporation may transact business in any part of the
            world.

            THIRTEENTH: - The Board of Directors of the Corporation is expressly
            authorized to make, alter or repeal the By-Laws of the Corporation
            by a vote of the majority of the entire Board. The stockholders may
            make, alter or repeal any By-Law whether or not adopted by them,
            provided however, that any such additional By-Laws, alterations or
            repeal may be adopted only by the affirmative vote of the holders of
            two-thirds or more of the outstanding shares of capital stock of the
            Corporation entitled to vote generally in the election of directors
            (considered for this purpose as one class).

            FOURTEENTH: - Meetings of the Directors may be held outside
            of the State of Delaware at such places as may be from time to time
            designated by the Board, and the Directors may keep the books of the
            Company outside of the State of Delaware at such places as may be
            from time to time designated by them.

            FIFTEENTH: - (a) In addition to any affirmative vote required by
            law, and except as otherwise expressly provided in sections (b) and
            (c) of this Article FIFTEENTH:

                    (A) any merger or consolidation of the Corporation or any
                    Subsidiary (as hereinafter defined) with or into (i) any
                    Interested Stockholder (as hereinafter defined) or (ii) any
                    other corporation (whether or not itself an Interested
                    Stockholder), which, after such merger or consolidation,
                    would be an Affiliate (as hereinafter defined) of an
                    Interested Stockholder, or

                    (B) any sale, lease, exchange, mortgage, pledge, transfer or
                    other disposition (in one transaction or a series of related
                    transactions) to or with any Interested Stockholder or any
                    Affiliate of any Interested Stockholder of any assets of the
                    Corporation or any Subsidiary having an aggregate fair
                    market value of $1,000,000 or more, or

                    (C) the issuance or transfer by the Corporation or any
                    Subsidiary (in one transaction or a series of related
                    transactions) of any securities of the Corporation or any
                    Subsidiary to any Interested Stockholder or any Affiliate of
                    any Interested Stockholder in exchange for cash, securities
                    or 
<PAGE>   15
                                                                         Page 15


                    other property (or a combination thereof) having an
                    aggregate fair market value of $1,000,000 or more, or

                    (D) the adoption of any plan or proposal for the liquidation
                    or dissolution of the Corporation, or

                    (E) any reclassification of securities (including any
                    reverse stock split), or recapitalization of the
                    Corporation, or any merger or consolidation of the
                    Corporation with any of its Subsidiaries or any similar
                    transaction (whether or not with or into or otherwise
                    involving an Interested Stockholder) which has the effect,
                    directly or indirectly, of increasing the proportionate
                    share of the outstanding shares of any class of equity or
                    convertible securities of the Corporation or any Subsidiary
                    which is directly or indirectly owned by any Interested
                    Stockholder, or any Affiliate of any Interested Stockholder,

shall require the affirmative vote of the holders of at least two-thirds of the
outstanding shares of capital stock of the Corporation entitled to vote
generally in the election of directors, considered for the purpose of this
Article FIFTEENTH as one class ("Voting Shares"). Such affirmative vote shall be
required notwithstanding the fact that no vote may be required, or that some
lesser percentage may be specified, by law or in any agreement with any national
securities exchange or otherwise.

                      (2) The term "business combination" as used in this
                      Article FIFTEENTH shall mean any transaction which is
                      referred to any one or more of clauses (A) through (E) of
                      paragraph 1 of the section (a).

                    (b) The provisions of section (a) of this Article FIFTEENTH
                    shall not be applicable to any particular business
                    combination and such business combination shall require only
                    such affirmative vote as is required by law and any other
                    provisions of the Charter or Act of Incorporation of By-Laws
                    if such business combination has been approved by a majority
                    of the whole Board.

                    (c) For the purposes of this Article FIFTEENTH:

            (1) A "person" shall mean any individual firm, corporation or other
            entity.

            (2) "Interested Stockholder" shall mean, in respect of any business
            combination, any person (other than the Corporation or any
            Subsidiary) who or which as of the record date for the determination
            of stockholders entitled to notice of and to vote on such business
            combination, or immediately prior to the consummation of any such
            transaction:

                    (A) is the beneficial owner, directly or indirectly, of more
                    than 10% of the Voting Shares, or
<PAGE>   16
                                                                         Page 16


                    (B) is an Affiliate of the Corporation and at any time
                    within two years prior thereto was the beneficial owner,
                    directly or indirectly, of not less than 10% of the then
                    outstanding voting Shares, or

                    (C) is an assignee of or has otherwise succeeded in any
                    share of capital stock of the Corporation which were at any
                    time within two years prior thereto beneficially owned by
                    any Interested Stockholder, and such assignment or
                    succession shall have occurred in the course of a
                    transaction or series of transactions not involving a public
                    offering within the meaning of the Securities Act of 1933.

            (3) A person shall be the "beneficial owner" of any Voting Shares:

                    (A) which such person or any of its Affiliates and
                    Associates (as hereafter defined) beneficially own, directly
                    or indirectly, or

                    (B) which such person or any of its Affiliates or Associates
                    has (i) the right to acquire (whether such right is
                    exercisable immediately or only after the passage of time),
                    pursuant to any agreement, arrangement or understanding or
                    upon the exercise of conversion rights, exchange rights,
                    warrants or options, or otherwise, or (ii) the right to vote
                    pursuant to any agreement, arrangement or understanding, or

                    (C) which are beneficially owned, directly or indirectly, by
                    any other person with which such first mentioned person or
                    any of its Affiliates or Associates has any agreement,
                    arrangement or understanding for the purpose of acquiring,
                    holding, voting or disposing of any shares of capital stock
                    of the Corporation.

            (4) The outstanding Voting Shares shall include shares deemed owned
            through application of paragraph (3) above but shall not include any
            other Voting Shares which may be issuable pursuant to any agreement,
            or upon exercise of conversion rights, warrants or options or
            otherwise.

            (5) "Affiliate" and "Associate" shall have the respective meanings
            given those terms in Rule 12b-2 of the General Rules and Regulations
            under the Securities Exchange Act of 1934, as in effect on December
            31, 1981.

            (6) "Subsidiary" shall mean any corporation of which a majority of
            any class of equity security (as defined in Rule 3a11-1 of the
            General Rules and Regulations under the Securities Exchange Act of
            1934, as in effect in December 31, 1981) is owned, directly or
            indirectly, by the Corporation; provided, however, that for the
            purposes of the definition of Investment Stockholder set forth in
            paragraph (2) of this section (c), the term "Subsidiary" shall mean
            only a corporation of which a majority of each class of equity
<PAGE>   17
                                                                         Page 17


            security is owned, directly or indirectly, by the Corporation.

                    (d) majority of the directors shall have the power and duty
                    to determine for the purposes of this Article FIFTEENTH on
                    the basis of information known to them, (1) the number of
                    Voting Shares beneficially owned by any person (2) whether
                    a person is an Affiliate or Associate of another, (3)
                    whether a person has an agreement, arrangement or
                    understanding with another as to the matters referred to in
                    paragraph (3) of section (c), or (4) whether the assets
                    subject to any business combination or the consideration
                    received for the issuance or transfer of securities by the
                    Corporation, or any Subsidiary has an aggregate fair market
                    value of $1,000,000 or more.

                    (e) Nothing contained in this Article FIFTEENTH shall be
                    construed to relieve any Interested Stockholder from any
                    fiduciary obligation imposed by law.

            SIXTEENTH: Notwithstanding any other provision of this Charter or
            Act of Incorporation or the By-Laws of the Corporation (and in
            addition to any other vote that may be required by law, this Charter
            or Act of Incorporation by the By-Laws), the affirmative vote of the
            holders of at least two-thirds of the outstanding shares of the
            capital stock of the Corporation entitled to vote generally in the
            election of directors (considered for this purpose as one class)
            shall be required to amend, alter or repeal any provision of
            Articles FIFTH, THIRTEENTH, FIFTEENTH or SIXTEENTH of this Charter
            or Act of Incorporation.

            SEVENTEENTH: (a) a Director of this Corporation shall not be liable
            to the Corporation or its stockholders for monetary damages for
            breach of fiduciary duty as a Director, except to the extent such
            exemption from liability or limitation thereof is not permitted
            under the Delaware General Corporation Laws as the same exists or
            may hereafter be amended.

                    (b) Any repeal or modification of the foregoing paragraph
                    shall not adversely affect any right or protection of a
                    Director of the Corporation existing hereunder with respect
                    to any act or omission occurring prior to the time of such
                    repeal or modification."
<PAGE>   18
                                                                         Page 18


                                    EXHIBIT B

                                     BY-LAWS


                            WILMINGTON TRUST COMPANY

                              WILMINGTON, DELAWARE

                         AS EXISTING ON JANUARY 16, 1997
<PAGE>   19
                                                                         Page 19


                       BY-LAWS OF WILMINGTON TRUST COMPANY


                                    ARTICLE I
                             STOCKHOLDERS' MEETINGS

            Section 1. The Annual Meeting of Stockholders shall be held on the
third Thursday in April each year at the principal office at the Company or at
such other date, time, or place as may be designated by resolution by the Board
of Directors.

            Section 2. Special meetings of all stockholders may be called at any
time by the Board of Directors, the Chairman of the Board or the President.

            Section 3. Notice of all meetings of the stockholders shall be given
by mailing to each stockholder at least ten (10) days before said meeting, at
his last known address, a written or printed notice fixing the time and place of
such meeting.

            Section 4. A majority in the amount of the capital stock of the
Company issued and outstanding on the record date, as herein determined, shall
constitute a quorum at all meetings of stockholders for the transaction of any
business, but the holders of a small number of shares may adjourn, from time to
time, without further notice, until a quorum is secured. At each annual or
special meeting of stockholders, each stockholder shall be entitled to one vote,
either in person or by proxy, for each shares of stock registered in the
stockholder's name on the books of the Company on the record date for any such
meeting as determined herein.


                                   ARTICLE II
                                    DIRECTORS

            Section 1. The number and classification of the Board of Directors
shall be as set forth in the Charter of the Bank.

            Section 2. No person who has attained the age of seventy-two (72)
years shall be nominated for election to the Board of Directors of the Company,
provided, however, that this limitation shall not apply to any person who was
serving as director of the Company on September 16, 1971.

            Section 3. The class of Directors so elected shall hold office for
three years or until their successors are elected and qualified.

            Section 4. The affairs and business of the Company shall be managed
and conducted by the Board of Directors.

            Section 5. The Board of Directors shall meet at the principal office
of the Company or elsewhere in its discretion at such times to be determined by
a majority of 
<PAGE>   20
                                                                         Page 20


its members, or at the call of the Chairman of the Board of Directors or the
President.

            Section 6. Special meetings of the Board of Directors may be called
at any time by the Chairman of the Board of Directors or by the President, and
shall be called upon the written request of a majority of the directors.

            Section 7. A majority of the directors elected and qualified shall
be necessary to constitute a quorum for the transaction of business at any
meeting of the Board of Directors.

            Section 8. Written notice shall be sent by mail to each director of
any special meeting of the Board of Directors, and of any change in the time or
place of any regular meeting, stating the time and place of such meeting, which
shall be mailed not less than two days before the time of holding such meeting.

            Section 9. In the event of the death, resignation, removal,
inability to act, or disqualification of any director, the Board of Directors,
although less than a quorum, shall have the right to elect the successor who
shall hold office for the remainder of the full term of the class of directors
in which the vacancy occurred, and until such director's successor shall have
been duly elected and qualified.

            Section 10. The Board of Directors at its first meeting after its
election by the stockholders shall appoint an Executive Committee, a Trust
Committee, an Audit Committee and a Compensation Committee, and shall elect from
its own members a Chairman of the Board of Directors and a President who may be
the same person. The Board of Directors shall also elect at such meeting a
Secretary and a Treasurer, who may be the same person, may appoint at any time
such other committees and elect or appoint such other officers as it may deem
advisable. The Board of Directors may also elect at such meeting one or more
Associate Directors.

            Section 11. The Board of Directors may at any time remove, with or
without cause, any member of any Committee appointed by it or any associate
director or officer elected by it and may appoint or elect his successor.

            Section 12. The Board of Directors may designate an officer to be in
charge of such of the departments or division of the Company as it may deem
advisable.
<PAGE>   21
                                                                         Page 21


                                   ARTICLE III
                                   COMMITTEES

            Section 1.  Executive Committee

                        (A) The Executive Committee shall be composed of not
more than nine members who shall be selected by the Board of Directors from its
own members and who shall hold office during the pleasure of the Board.

                        (B) The Executive Committee shall have all the powers of
the Board of Directors when it is not in session to transact all business for
and in behalf of the Company that may be brought before it.

                        (C) The Executive Committee shall meet at the principal
office of the Company or elsewhere in its discretion at such times to be
determined by a majority of its members, or at the call of the Chairman of the
Executive Committee or at the call of the Chairman of the Board of Directors.
The majority of its members shall be necessary to constitute a quorum for the
transaction of business. Special meetings of the Executive Committee may be held
at any time when a quorum is present.

                        (D) Minutes of each meeting of the Executive Committee
shall be kept and submitted to the Board of Directors at its next meeting.

                        (E) The Executive Committee shall advise and superintend
all investments that may be made of the funds of the Company, and shall direct
the disposal of the same, in accordance with such rules and regulations as the
Board of Directors from time to time make.

                        (F) In the event of a state of disaster of sufficient
severity to prevent the conduct and management of the affairs and business of
the Company by its directors and officers as contemplated by these By-Laws any
two available members of the Executive Committee as constituted immediately
prior to such disaster shall constitute a quorum of that Committee for the full
conduct and management of the affairs and business of the Company in accordance
with the provisions of Article III of these By-Laws; and if less than three
members of the Trust Committee is constituted immediately prior to such disaster
shall be available for the transaction of its business, such Executive Committee
shall also be empowered to exercise all of the powers reserved to the Trust
Committee under Article III Section 2 hereof. In the event of the
unavailability, at such time, of a minimum of two members of such Executive
Committee, any three available directors shall constitute the Executive
Committee for the full conduct and management of the affairs and business of the
Company in accordance with the foregoing provisions of this Section. This By-Law
shall be subject to implementation by Resolutions of the Board of Directors
presently existing or hereafter passed from time to time for that purpose, and
any provisions of these By-Laws (other than this Section) and any resolutions
which are contrary to the provisions of this Section or to the provisions of any
such implementary Resolutions 
<PAGE>   22
                                                                         Page 22


shall be suspended during such a disaster period until it shall be determined by
any interim Executive Committee acting under this section that it shall be to
the advantage of the Company to resume the conduct and management of its affairs
and business under all of the other provisions of these By-Laws.

            Section 2.  Trust Committee

                        (A) The Trust Committee shall be composed of not more
than thirteen members who shall be selected by the Board of Directors, a
majority of whom shall be members of the Board of Directors and who shall hold
office during the pleasure of the Board.

                        (B) The Trust Committee shall have general supervision
over the Trust Department and the investment of trust funds, in all matters,
however, being subject to the approval of the Board of Directors.

                        (C) The Trust Committee shall meet at the principal
office of the Company or elsewhere in its discretion at such times to be
determined by a majority of its members or at the call of its chairman. A
majority of its members shall be necessary to constitute a quorum for the
transaction of business.

                        (D) Minutes of each meeting of the Trust Committee shall
be kept and promptly submitted to the Board of Directors.

                        (E) The Trust Committee shall have the power to appoint
Committees and/or designate officers or employees of the Company to whom
supervision over the investment of trust funds may be delegated when the Trust
Committee is not in session.

            Section 3.  Audit Committee

                        (A) The Audit Committee shall be composed of five
members who shall be selected by the Board of Directors from its own members,
none of whom shall be an officer of the Company, and shall hold office at the
pleasure of the Board.

                        (B) The Audit Committee shall have general supervision
over the Audit Division in all matters however subject to the approval of the
Board of Directors; it shall consider all matters brought to its attention by
the officer in charge of the Audit Division, review all reports of examination
of the Company made by any governmental agency or such independent auditor
employed for that purpose, and make such recommendations to the Board of
Directors with respect thereto or with respect to any other matters pertaining
to auditing the Company as it shall deem desirable.

                        (C) The Audit Committee shall meet whenever and wherever
the majority of its members shall deem it to be proper for the transaction of
its business, and a majority of its Committee shall constitute a quorum.
<PAGE>   23
                                                                         Page 23


            Section 4.  Compensation Committee

                        (A) The Compensation Committee shall be composed of not
more than five (5) members who shall be selected by the Board of Directors from
its own members who are not officers of the Company and who shall hold office
during the pleasure of the Board.

                        (B) The Compensation Committee shall in general advise
upon all matters of policy concerning the Company brought to its attention by
the management and from time to time review the management of the Company, major
organizational matters, including salaries and employee benefits and
specifically shall administer the Executive Incentive Compensation Plan.

                        (C) Meetings of the Compensation Committee may be called
at any time by the Chairman of the Compensation Committee, the Chairman of the
Board of Directors, or the President of the Company.

            Section 5.  Associate Directors

                        (A) Any person who has served as a director may be
elected by the Board of Directors as an associate director, to serve during the
pleasure of the Board.

                        (B) An associate director shall be entitled to attend
all directors meetings and participate in the discussion of all matters brought
to the Board, with the exception that he would have no right to vote. An
associate director will be eligible for appointment to Committees of the
Company, with the exception of the Executive Committee, Audit Committee and
Compensation Committee, which must be comprised solely of active directors.

            Section 6.  Absence or Disqualification of Any Member of a Committee

                        (A) In the absence or disqualification of any member of
any Committee created under Article III of the By-Laws of this Company, the
member or members thereof present at any meeting and not disqualified from
voting, whether or not he or they constitute a quorum, may unanimously appoint
another member of the Board of Directors to act at the meeting in the place of
any such absence or disqualified member.


                                   ARTICLE IV
                                    OFFICERS

            Section 1. The Chairman of the Board of Directors shall preside at
all meetings of the Board and shall have such further authority and powers and
shall perform such duties as the Board of Directors may from time to time confer
and direct. 
<PAGE>   24
                                                                         Page 24


He shall also exercise such powers and perform such duties as may from time to
time be agreed upon between himself and the President of the Company.

            Section 2. The Vice Chairman of the Board. The Vice Chairman of the
Board of Directors shall preside at all meetings of the Board of Directors at
which the Chairman of the Board shall not be present and shall have such further
authority and powers and shall perform such duties as the Board of Directors or
the Chairman of the Board may from time to time confer and direct.

            Section 3. The President shall have the powers and duties pertaining
to the office of the President conferred or imposed upon him by statute or
assigned to him by the Board of Directors in the absence of the Chairman of the
Board the President shall have the powers and duties of the Chairman of the
Board.

            Section 4. The Chairman of the Board of Directors or the President
as designated by the Board of Directors, shall carry into effect all legal
directions of the Executive Committee and of the Board of Directors, and shall
at all times exercise general supervision over the interest, affairs and
operations of the Company and perform all duties incident to his office.

            Section 5. There may be one or more Vice Presidents, however
denominated by the Board of Directors, who may at any time perform all the
duties of the Chairman of the Board of Directors and/or the President and such
other powers and duties as may from time to time be assigned to them by the
Board of Directors, the Executive Committee, the Chairman of the Board or the
President and by the officer in charge of the department or division to which
they are assigned.

            Section 6. The Secretary shall attend to the giving of notice of
meetings of the stockholders and the Board of Directors, as well as the
Committees thereof, to the keeping of accurate minutes of all such meetings and
to recording the same in the minute books of the Company. In addition to the
other notice requirements of these By-Laws and as may be practicable under the
circumstances, all such notices shall be in writing and mailed well in advance
of the scheduled date of any other meeting. He shall have custody of the
corporate seal and shall affix the same to any documents requiring such
corporate seal and to attest the same.

            Section 7. The Treasurer shall have general supervision over all
assets and liabilities of the Company. He shall be custodian of and responsible
for all monies, funds and valuables of the Company and for the keeping of proper
records of the evidence of property or indebtedness and of all the transactions
of the Company. He shall have general supervision of the expenditures of the
Company and shall report to the Board of Directors at each regular meeting of
the condition of the Company, and perform such other duties as may be assigned
to him from time to time by the Board of Directors of the Executive Committee.

            Section 8. There may be a Controller who shall exercise general
supervision 
<PAGE>   25
                                                                         Page 25


over the internal operations of the Company, including accounting, and shall
render to the Board of Directors at appropriate times a report relating to the
general condition and internal operations of the Company.

            There may be one or more subordinate accounting or controller
officers however denominated, who may perform the duties of the Controller and
such duties as may be prescribed by the Controller.

            Section 9. The officer designated by the Board of Directors to be in
charge of the Audit Division of the Company with such title as the Board of
Directors shall prescribe, shall report to and be directly responsible only to
the Board of Directors.

            There shall be an Auditor and there may be one or more Audit
Officers, however denominated, who may perform all the duties of the Auditor and
such duties as may be prescribed by the officer in charge of the Audit Division.

            Section 10. There may be one or more officers, subordinate in rank
to all Vice Presidents with such functional titles as shall be determined from
time to time by the Board of Directors, who shall ex officio hold the office
Assistant Secretary of this Company and who may perform such duties as may be
prescribed by the officer in charge of the department or division to whom they
are assigned.

            Section 11. The powers and duties of all other officers of the
Company shall be those usually pertaining to their respective offices, subject
to the direction of the Board of Directors, the Executive Committee, Chairman of
the Board of Directors or the President and the officer in charge of the
department or division to which they are assigned.


                                    ARTICLE V
                          STOCK AND STOCK CERTIFICATES

            Section 1. Shares of stock shall be transferrable on the books of
the Company and a transfer book shall be kept in which all transfers of stock
shall be recorded.

            Section 2. Certificate of stock shall bear the signature of the
President or any Vice President, however denominated by the Board of Directors
and countersigned by the Secretary or Treasurer or an Assistant Secretary, and
the seal of the corporation shall be engraved thereon. Each certificate shall
recite that the stock represented thereby is transferrable only upon the books
of the Company by the holder thereof or his attorney, upon surrender of the
certificate properly endorsed. Any certificate of stock surrendered to the
Company shall be cancelled at the time of transfer, and before a new certificate
or certificates shall be issued in lieu thereof. Duplicate certificates of stock
shall be issued only upon giving such security as may be satisfactory to the
Board of Directors or the Executive Committee.
<PAGE>   26
                                                                         Page 26


            Section 3. The Board of Directors of the Company is authorized to
fix in advance a record date for the determination of the stockholders entitled
to notice of, and to vote at, any meeting of stockholders and any adjournment
thereof, or entitled to receive payment of any dividend, or to any allotment or
rights, or to exercise any rights in respect of any change, conversion or
exchange of capital stock, or in connection with obtaining the consent of
stockholders for any purpose, which record date shall not be more than 60 nor
less than 10 days proceeding the date of any meeting of stockholders or the date
for the payment of any dividend, or the date for the allotment of rights, or the
date when any change or conversion or exchange of capital stock shall go into
effect, or a date in connection with obtaining such consent.


                                   ARTICLE VI
                                      SEAL

            Section 1. The corporate seal of the Company shall be in the
following form:

                        Between two concentric circles the words "Wilmington
                        Trust Company" within the inner circle the words
                        "Wilmington, Delaware."


                                   ARTICLE VII
                                   FISCAL YEAR

            Section 1. The fiscal year of the Company shall be the calendar
year.
<PAGE>   27
                                                                         Page 27


                                  ARTICLE VIII
                     EXECUTION OF INSTRUMENTS OF THE COMPANY

            Section 1. The Chairman of the Board, the President or any Vice
President, however denominated by the Board of Directors, shall have full power
and authority to enter into, make, sign, execute, acknowledge and/or deliver and
the Secretary or any Assistant Secretary shall have full power and authority to
attest and affix the corporate seal of the Company to any and all deeds,
conveyances, assignments, releases, contracts, agreements, bonds, notes,
mortgages and all other instruments incident to the business of this Company or
in acting as executor, administrator, guardian, trustee, agent or in any other
fiduciary or representative capacity by any and every method of appointment or
by whatever person, corporation, court officer or authority in the State of
Delaware, or elsewhere, without any specific authority, ratification, approval
or confirmation by the Board of Directors or the Executive Committee, and any
and all such instruments shall have the same force and validity as though
expressly authorized by the Board of Directors and/or the Executive Committee.


                                   ARTICLE IX
               COMPENSATION OF DIRECTORS AND MEMBERS OF COMMITTEES

            Section 1. Directors and associate directors of the Company, other
than salaried officers of the Company, shall be paid such reasonable honoraria
or fees for attending meetings of the Board of Directors as the Board of
Directors may from time to time determine. Directors and associate directors who
serve as members of committees, other than salaried employees of the Company,
shall be paid such reasonable honoraria or fees for services as members of
committees as the Board of Directors shall from time to time determine and
directors and associate directors may be employed by the Company for such
special services as the Board of Directors may from time to time determine and
shall be paid for such special services so performed reasonable compensation as
may be determined by the Board of Directors.


                                    ARTICLE X
                                 INDEMNIFICATION

            Section 1. (A) The Corporation shall indemnify and hold harmless, to
the fullest extent permitted by applicable law as it presently exists or may
hereafter be amended, any person who was or is made or is threatened to be made
a party or is otherwise involved in any action, suit or proceeding, whether
civil, criminal, administrative or investigative (a "proceeding") by reason of
the fact that he, or a person for whom he is the legal representative, is or was
a director, officer, employee or agent of the Corporation or is or was serving
at the request of the Corporation as a director, officer, employee, fiduciary or
agent of another corporation or of a partnership, joint venture, trust,
enterprise or non-profit entity, including service with respect to employee
<PAGE>   28
                                                                         Page 28


benefit plans, against all liability and loss suffered and expenses reasonably
incurred by such person. The Corporation shall indemnify a person in connection
with a proceeding initiated by such person only if the proceeding was authorized
by the Board of Directors of the Corporation.

                        (B) The Corporation shall pay the expenses incurred in
defending any proceeding in advance of its final disposition, provided, however,
that the payment of expenses incurred by a Director officer in his capacity as a
Director or officer in advance of the final disposition of the proceeding shall
be made only upon receipt of an undertaking by the Director or officer to repay
all amounts advanced if it should be ultimately determined that the Director or
officer is not entitled to be indemnified under this Article or otherwise.

                        (C) If a claim for indemnification or payment of
expenses, under this Article X is not paid in full within ninety days after a
written claim therefor has been received by the Corporation the claimant may
file suit to recover the unpaid amount of such claim and, if successful in whole
or in part, shall be entitled to be paid the expense of prosecuting such claim.
In any such action the Corporation shall have the burden of proving that the
claimant was not entitled to the requested indemnification of payment of
expenses under applicable law.

                        (D) The rights conferred on any person by this Article X
shall not be exclusive of any other rights which such person may have or
hereafter acquire under any statute, provision of the Charter or Act of
Incorporation, these By-Laws, agreement, vote of stockholders or disinterested
Directors or otherwise.

                        (E) Any repeal or modification of the foregoing
provisions of this Article X shall not adversely affect any right or protection
hereunder of any person in respect of any act or omission occurring prior to the
time of such repeal or modification.


                                   ARTICLE XI
                            AMENDMENTS TO THE BY-LAWS

            Section 1. These By-Laws may be altered, amended or repealed, in
whole or in part, and any new By-Law or By-Laws adopted at any regular or
special meeting of the Board of Directors by a vote of the majority of all the
members of the Board of Directors then in office.
<PAGE>   29
                                                                         Page 29


                                    EXHIBIT C




                             SECTION 321(b) CONSENT


            Pursuant to Section 321(b) of the Trust Indenture Act of 1939, as
amended, Wilmington Trust Company hereby consents that reports of examinations
by Federal, State, Territorial or District authorities may be furnished by such
authorities to the Securities and Exchange Commission upon requests therefor.



                                             WILMINGTON TRUST COMPANY


Dated: December 10, 1998                     By:/s/ James P. Lawler           
                                                -------------------
                                             Name:  James P. Lawler
                                             Title: Vice President
<PAGE>   30
                                                                         Page 30


                                    EXHIBIT D



                                     NOTICE


            This form is intended to assist state nonmember banks and savings
            banks with state publication requirements. It has not been approved
            by any state banking authorities. Refer to your appropriate state
            banking authorities for your state publication requirements.



R E P O R T   O F   C O N D I T I O N

Consolidating domestic subsidiaries of the

           WILMINGTON TRUST COMPANY        of     WILMINGTON    
                 Name of Bank                        City

in the State of DELAWARE, at the close of business on September 30, 1998.



<TABLE>
<CAPTION>
ASSETS
                                                                              Thousands of dollars
<S>                                                                           <C>    
Cash and balances due from depository institutions:                           
Noninterest-bearing balances and currency and coins ......................           180,755
Interest-bearing balances ................................................                 0
Held-to-maturity securities ..............................................           148,529
Available-for-sale securities ............................................         1,216,482
Federal funds sold and securities purchased under agreements to resell ...           203,500
Loans and lease financing receivables:                                        
Loans and leases, net of unearned income .................................         3,951,771
LESS:  Allowance for loan and lease losses ...............................            64,835
LESS:  Allocated transfer risk reserve ...................................                 0
Loans and leases, net of unearned income, allowance, and reserve .........         3,886,936
Assets held in trading accounts ..........................................                 0
Premises and fixed assets (including capitalized leases) .................           137,819
Other real estate owned ..................................................             1,847
Investments in unconsolidated subsidiaries and associated companies ......               997
Customers' liability to this bank on acceptances outstanding .............                 0
Intangible assets ........................................................             3,105
Other assets .............................................................            82,400
Total assets .............................................................         5,862,370
</TABLE>



CONTINUED ON NEXT PAGE
<PAGE>   31
                                                                         Page 31


<TABLE>
<S>                                                                                  <C>      
LIABILITIES

Deposits:
In domestic offices ..........................................................       4,338,785
     Noninterest-bearing .....................................................         792,528
     Interest-bearing ........................................................       3,546,257
Federal funds purchased and Securities sold under agreements to repurchase ...         249,670
Demand notes issued to the U.S. Treasury .....................................          74,347
Trading liabilities (from Schedule RC-D) .....................................               0
Other borrowed money:                                                                  ///////
     With original maturity of one year or less ..............................         576,507
     With original maturity of more than one year ............................          43,000
Bank's liability on acceptances executed and outstanding .....................               0
Subordinated notes and debentures ............................................               0
Other liabilities (from Schedule RC-G) .......................................         104,687
Total liabilities ............................................................       5,386,996


EQUITY CAPITAL

Perpetual preferred stock and related surplus ................................               0
Common Stock .................................................................             500
Surplus (exclude all surplus related to preferred stock) .....................          62,118
Undivided profits and capital reserves .......................................         399,222
Net unrealized holding gains (losses) on available-for-sale securities .......          13,534
Total equity capital .........................................................         475,374
Total liabilities, limited-life preferred stock, and equity capital ..........       5,862,370
</TABLE>

<PAGE>   1
 
                                                                    EXHIBIT 99.1
 
                             LETTER OF TRANSMITTAL
 
                          AMERICA WEST AIRLINES, INC.
 
                               OFFER TO EXCHANGE
                   PASS THROUGH CERTIFICATES, SERIES 1998-1,
                           WHICH HAVE BEEN REGISTERED
                 UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
                          FOR ANY AND ALL OUTSTANDING
                    PASS THROUGH CERTIFICATES, SERIES 1998-1
 
            PURSUANT TO THE PROSPECTUS, DATED                , 1999.
 
THE EXCHANGE OFFER WILL EXPIRE AT 5:00 P.M. NEW YORK CITY TIME, ON
             , 1999, UNLESS EXTENDED (THE "EXPIRATION DATE"). TENDERS MAY BE
WITHDRAWN PRIOR TO 5:00 P.M., NEW YORK CITY TIME, ON              , 1999.
 
                            WILMINGTON TRUST COMPANY
                                 EXCHANGE AGENT
 
<TABLE>
<S>                                            <C>
        By Mail or Overnight Delivery:                            By Hand:
           Wilmington Trust Company                       Wilmington Trust Company
           1100 North Market Street                 1105 North Market Street, 1st Floor
       Wilmington, Delaware 19890-0001                   Wilmington, Delaware 19890
           Attention: Kristin Long                 Attention: Corporate Trust Operations
</TABLE>
 
                            Facsimile Transmission:
                                 (302) 651-1079
 
                             Confirm by Telephone:
                                 (302) 651-1562
                                  Kristin Long
 
  DELIVERY OF THIS INSTRUMENT TO AN ADDRESS OTHER THAN AS SET FORTH ABOVE, OR
 TRANSMISSION OF INSTRUCTIONS VIA FACSIMILE OTHER THAN AS SET FORTH ABOVE, WILL
                        NOT CONSTITUTE A VALID DELIVERY.
 
     The undersigned acknowledges receipt of the Prospectus, dated (the
"Prospectus"), of America West Airlines, Inc., a Delaware corporation (the
"Company" or "America West"), and this Letter of Transmittal (this "Letter"),
which together constitute the offer (the "Exchange Offer") to exchange an
aggregate principal amount of up to $190,529,000 of Pass Through Certificates,
Series 1998-1, which have been registered under the Securities Act of 1933, as
amended (the "New Certificates"), for an equal principal amount of the
outstanding Pass Through Certificates, Series 1998-1 (the "Old Certificates").
The Exchange Offer is being made in order to satisfy certain obligations of the
Company contained in the Exchange and Registration Rights Agreement, dated as of
October 6, 1998, between the Company and the Initial Purchasers named therein
(the "Registration Rights Agreement").
<PAGE>   2
 
     For each Old Certificate accepted for exchange, the holder of such Old
Certificate (the "Holder") will receive a New Certificate having a principal
amount equal to that of the surrendered Old Certificate. New Certificates will
accrue interest at the applicable per annum rate for such New Certificates as
set forth on the cover page of the Prospectus, from the date on which the Old
Certificates surrendered in exchange therefor were originally issued (the
"Issuance Date"). Interest on the New Certificates is payable on January 2 and
July 2 of each year, commencing January 2, 1999, subject to the terms of the
Intercreditor Agreement (as defined in the Prospectus).
 
     In the event that neither the consummation of the Exchange Offer nor the
declaration by the Securities and Exchange Commission of a Shelf Registration
Statement relating to the sale of the Old Certificates to be effective (each a
"Registration Event") occurs on or prior to the 210th calendar day after the
Issuance Date, the interest rate per annum passed through to holders of Old
Certificates shall be increased by 0.50% from and including such 210th day to
but excluding the earlier of (i) the date on which a Registration Event occurs
and (ii) the date on which all of the Old Certificates otherwise become
transferable by Certificateholders (other than affiliates or former affiliates
of America West) without further registration under the Securities Act. In the
event that such Shelf Registration Statement ceases to be effective at any time
during the period specified by the Registration Rights Agreement for more than
60 days, whether or not consecutive, during any 12-month period, the interest
rate per annum passed through to the holders of Old Certificates shall be
increased by 0.50% from the 61st day of the applicable 12-month period such
Shelf Registration Statement ceases to be effective until such time as such
Shelf Registration Statement again becomes effective (or, if earlier, the end of
such period specified by the Registration Rights Agreement).
 
     The Company reserves the right, at any time or from time to time, to extend
the Exchange Offer at its discretion, in which event the term "Expiration Date"
shall mean the latest time and date to which the Exchange Offer is extended. The
Company shall notify the holders of the Old Certificates of any extension by
means of a press release or other public announcement prior to 9:00 A.M., New
York City time, on the next business day after the previously scheduled
Expiration Date.
 
     This Letter is to be completed by a holder of Old Certificates if Old
Certificates are to be forwarded herewith or if a tender of Old Certificates is
to be made by book-entry transfer through the Automated Tender Offer Program
("ATOP") at The Depository Trust Company (the "DTC") pursuant to the procedure
set forth in "The Exchange Offer -- Book-Entry Transfer" section of the
Prospectus.
 
     Holders who are participants in DTC ("DTC Participants") tendering by
book-entry transfer must execute such tender through ATOP on or prior to the
Expiration Date. DTC will verify such acceptance, execute a book-entry transfer
of the tendered Old Certificates into the Exchange Agent's account at DTC and
then send to the Exchange Agent confirmation of such book-entry transfer
("Book-Entry Confirmation") including an agent's message ("Agent's Message")
confirming that DTC has received an express acknowledgment from such Holder that
such Holder has received and agrees to be bound by this Letter of Transmittal
and that the Trust and the Company may enforce this Letter of Transmittal
against such Holder. The book-entry confirmation must be received by the
Exchange Agent in order for the tender relating thereto to be effective.
Book-entry transfer to DTC in accordance with DTC's procedures does not
constitute delivery of the book-entry confirmation to the Exchange Agent.
 
     If the tender is not made through ATOP, Old Certificates, as well as this
Letter of Transmittal (or facsimile hereof), properly completed and duly
executed, with any required signature guarantees, and any other documents
required by this Letter of Transmittal, must be received by the Exchange Agent
at its address set forth herein on or prior to the Expiration Date in order for
such tender to be effective.
 
     Holders of Old Certificates whose certificates are not immediately
available, or who are unable to deliver their certificates or confirmation of
the book-entry tender of their Old Certificates and all other documents required
by this Letter to the Exchange Agent on or prior to the Expiration Date, must
tender their Old Certificates according to the guaranteed delivery procedures
set forth in "The Exchange Offer -- Guaranteed Delivery Procedures" section of
the Prospectus. See Instruction 1.
 
                                        2
<PAGE>   3
 
     THE METHOD OF DELIVERY OF THE BOOK-ENTRY CONFIRMATION OR OLD CERTIFICATES,
THIS TRANSMITTAL LETTER, AND ALL OTHER REQUIRED DOCUMENTS IS AT THE OPTION AND
SOLE RISK OF THE TENDERING HOLDER, AND THE DELIVERY WILL BE DEEMED MADE ONLY
WHEN ACTUALLY RECEIVED BY THE EXCHANGE AGENT. IF DELIVERY IS BY MAIL, REGISTERED
MAIL WITH RETURN RECEIPT REQUESTED, PROPERLY INSURED, OR OVERNIGHT DELIVERY
SERVICE IS RECOMMENDED. IN ALL CASES, SUFFICIENT TIME SHOULD BE ALLOWED TO
ENSURE TIMELY DELIVERY.
 
     The undersigned has completed the appropriate boxes below and signed this
Letter to indicate the action the undersigned desires to take with respect to
the Exchange Offer.
 
     List below the Old Certificates to which this Letter relates. If the space
provided below is inadequate, the certificate numbers and principal amount of
Old Certificates should be listed on a separate signed schedule affixed hereto.
 
<TABLE>
<CAPTION>
- --------------------------------------------------------------------------------------------------------------------------
                                             DESCRIPTION OF OLD CERTIFICATES
- --------------------------------------------------------------------------------------------------------------------------
                     (1)                                                         (2)                     (3)
           NAME(S) AND ADDRESS(ES)                                            AGGREGATE
           OF REGISTERED HOLDER(S)                   CERTIFICATE           PRINCIPAL AMOUNT           PRINCIPAL
          (PLEASE FILL IN, IF BLANK)                   NUMBERS*          OF OLD CERTIFICATES      AMOUNT TENDERED**
<S>                                             <C>                     <C>                     <C>                    <C>
- --------------------------------------------------------------------------------------------------------------------------
 
                                                   -------------------------------------------------------------------
 
                                                   -------------------------------------------------------------------
 
                                                   -------------------------------------------------------------------
 
                                                   -------------------------------------------------------------------
                                                        Total:
- --------------------------------------------------------------------------------------------------------------------------
</TABLE>
 
   * Need not be completed by Holders of Notes being tendered by book-entry
     transfer (see below).
 
  ** Unless otherwise indicated, it will be assumed that all Notes represented
     by certificates delivered to the Depositary are being tendered. See
     Instruction 1.
- --------------------------------------------------------------------------------
 
                                        3
<PAGE>   4
 
[ ]     CHECK HERE IF TENDERED OLD CERTIFICATES ARE BEING DELIVERED BY
        BOOK-ENTRY TRANSFER MADE TO THE ACCOUNT MAINTAINED BY THE EXCHANGE AGENT
        WITH THE BOOK-ENTRY TRANSFER FACILITY AND COMPLETE THE FOLLOWING:
 
        Name of Tendering Institution:
      ------------------------------------------------------------------------
 
        Account Number:
      --------------------------------------------------------------------------
 
        Transaction Code Number:
 
    ----------------------------------------------------------------------------
- --------------------------------------------------------------------------------
 
[ ]     CHECK HERE IF TENDERED OLD CERTIFICATES ARE BEING DELIVERED PURSUANT TO
        A NOTICE OF GUARANTEED DELIVERY PREVIOUSLY SENT TO THE EXCHANGE AGENT
        AND COMPLETE THE FOLLOWING:
 
        Name(s) of Registered Holder(s):
      -------------------------------------------------------------------
 
        Window Ticket Number (if any):
      ---------------------------------------------------------------------
 
        Date of Execution of Notice of Guaranteed Delivery:
      ------------------------------------------------
 
        Name of Institution which guaranteed delivery:
      ------------------------------------------------------
 
        If Delivered by Book-Entry Transfer, Complete the Following:
 
        Account Number:
      --------------------------------------------------------------------------
 
        Transaction Code Number:
 
    ----------------------------------------------------------------------------
- --------------------------------------------------------------------------------
 
[ ]     CHECK HERE IF YOU ARE A BROKER-DEALER AND WISH TO RECEIVE 10 ADDITIONAL
        COPIES OF THE PROSPECTUS AND 10 COPIES OF ANY AMENDMENTS OR SUPPLEMENTS
        THERETO.
 
        Name:
      --------------------------------------------------------------------------
 
        Address:
      --------------------------------------------------------------------------
 
      --------------------------------------------------------------------------
 
                                        4
<PAGE>   5
 
              PLEASE READ THE ACCOMPANYING INSTRUCTIONS CAREFULLY
 
Ladies and Gentlemen:
 
     Upon the terms and subject to the conditions of the Exchange Offer, the
undersigned hereby tenders to the Company the aggregate principal amount of Old
Certificates indicated above. Subject to, and effective upon, the acceptance for
exchange of the Old Certificates tendered hereby, the undersigned hereby sells,
assigns and transfers to, or upon the order of, the Company all right, title and
interest in and to such Old Certificates as are being tendered hereby.
 
     The undersigned hereby represents and warrants that the undersigned has
full power and authority to tender, sell, assign and transfer the Old
Certificates tendered hereby and that the Company will acquire good and
unencumbered title thereto, free and clear of all liens, restrictions, charges
and encumbrances and not subject to any adverse claim when the same are accepted
by the Company. The undersigned hereby further represents that any New
Certificates acquired in exchange for Old Certificates tendered hereby will have
been acquired in the ordinary course of business of the person receiving such
New Certificates, whether or not such person is the undersigned, that neither
the holder of such Old Certificates nor any such other person is engaged in, or
intends to engage in a distribution of such New Certificates, or has an
arrangement or understanding with any person to participate in the distribution
of such New Certificates, and that neither the holder of such Old Certificates
nor any such other person is an "affiliate," as defined in Rule 405 under the
Securities Act of 1933, as amended (the "Securities Act"), of the Company.
 
     The undersigned also acknowledges that this Exchange Offer is being made
based upon the Company's understanding of an interpretation by the staff of the
Securities and Exchange Commission (the "Commission") as set forth in no-action
letters issued to third parties, including Exxon Capital Holdings Corporation,
SEC No-Action Letter (available May 13, 1988) (the "Exxon Capital Letter"),
Morgan Stanley & Co. Incorporated, SEC No-Action Letter (available June 5, 1991)
(the "Morgan Stanley Letter") and Shearman & Sterling, SEC No-Action Letter
(available July 2, 1993) (the "Shearman & Sterling Letter"), that the New
Certificates issued in exchange for the Old Certificates pursuant to the
Exchange Offer may be offered for resale, resold and otherwise transferred by
holders thereof (other than a broker-dealer who acquires such New Certificates
directly from the Company for resale pursuant to Rule 144A under the Securities
Act or any other available exemption under the Securities Act or any such holder
that is an "affiliate" of the Company within the meaning of Rule 405 under the
Securities Act), without compliance with the registration and prospectus
delivery provisions of the Securities Act, provided that such New Certificates
are acquired in the ordinary course of such holders' business and such holders
are not engaged in, and do not intend to engage in, a distribution of such New
Certificates and have no arrangement with any person to participate in the
distribution of such New Certificates.
 
     If a holder of Old Certificates is engaged in or intends to engage in a
distribution of the New Certificates or has any arrangement or understanding
with respect to the distribution of the New Certificates to be acquired pursuant
to the Exchange Offer, such holder could not rely on the applicable
interpretations of the staff of the Commission and must comply with the
registration and prospectus delivery requirements of the Securities Act in
connection with any secondary resale transaction. If the undersigned is a
broker-dealer that will receive New Certificates for its own account in exchange
for Old Certificates, it represents that the Old Certificates to be exchanged
for the New Certificates were acquired by it as a result of market-making
activities or other trading activities and acknowledges that it will deliver a
prospectus in connection with any resale of such New Certificates; however, by
so acknowledging and by delivering a prospectus, the undersigned will not be
deemed to admit that it is an "underwriter" within the meaning of the Securities
Act.
 
     The undersigned will, upon request, execute and deliver any additional
documents deemed by the Company to be necessary or desirable to complete the
sale, assignment and transfer of the Old Certificates tendered hereby. All
authority conferred or agreed to be conferred in this Letter and every
obligation of
 
                                        5
<PAGE>   6
 
the undersigned hereunder shall be binding upon the successors, assigns, heirs,
executors, administrators, trustees in bankruptcy and legal representatives of
the undersigned and shall not be affected by, and shall survive, the death or
incapacity of the undersigned. This tender may be withdrawn only in accordance
with the procedures set forth in "The Exchange Offer -- Withdrawal of Tenders"
section of the Prospectus.
 
     Unless otherwise indicated herein in the box entitled "Special Issuance
Instructions" below, please deliver the New Certificates (and, if applicable,
substitute certificates representing Old Certificates for any Old Certificates
not exchanged) in the name of the undersigned or, in the case of a book-entry
delivery of Old Certificates, please credit the account indicated above
maintained at the Book-Entry Transfer Facility. Similarly, unless otherwise
indicated under the box entitled "Special Delivery Instructions" below, please
send the New Certificates (and, if applicable, substitute certificates
representing Old Certificates for any Old Certificates not exchanged) to the
undersigned at the address shown above in the box entitled "Description of Old
Certificates."
 
     THE UNDERSIGNED, BY COMPLETING THE BOX ENTITLED "DESCRIPTION OF OLD
CERTIFICATES" ABOVE AND SIGNING THIS LETTER, WILL BE DEEMED TO HAVE TENDERED THE
OLD CERTIFICATES AS SET FORTH IN SUCH BOX ABOVE.
 
                                        6
<PAGE>   7
 
- ------------------------------------------------------
                         SPECIAL ISSUANCE INSTRUCTIONS
                           (SEE INSTRUCTIONS 3 AND 4)
- ------------------------------------------------------
 
      To be completed ONLY if certificates for Old Certificates not exchanged
 and/or New Certificates are to be issued in the name of and sent to someone
 other than the person(s) whose signature(s) appear(s) on this Letter below, or
 if Old Certificates delivered by book-entry transfer which are not accepted
 for exchange are to be returned by credit to an account maintained at the
 Book-Entry Transfer Facility other than the account indicated above.
 
 Issue:  New Certificates and/or Old Certificates to:
 
 Name(s):
 -----------------------------------------
                             (PLEASE TYPE OR PRINT)
 
 -----------------------------------------------------
 Address(es):
 --------------------------------------
 -----------------------------------------------------
                              (INCLUDING ZIP CODE)
 
 -----------------------------------------------------
              (SOCIAL SECURITY OR EMPLOYER IDENTIFICATION NUMBER)
 
 [ ]  Credit unexchanged Old Certificates delivered by book-entry transfer to
      the Book-Entry Transfer Facility account set forth below.
 
 -----------------------------------------------------
                         (BOOK-ENTRY TRANSFER FACILITY
                         ACCOUNT NUMBER, IF APPLICABLE)
- ------------------------------------------------------
 
- ------------------------------------------------------
                         SPECIAL DELIVERY INSTRUCTIONS
                           (SEE INSTRUCTIONS 3 AND 4)
- ------------------------------------------------------
 
      To be completed ONLY if certificates for Old Certificates not exchanged
 and/or New Certificates are to be sent to someone other than the person(s)
 whose signature(s) appear(s) on this letter below, or to the undersigned at an
 address other than shown in the box entitled "Description of Old Certificates"
 on this Letter above.
 
 Mail:  New Certificates and/or Old Certificates to:
 
 Name(s):
 -----------------------------------------
                             (PLEASE TYPE OR PRINT)
 
 -----------------------------------------------------
 Address:
 -------------------------------------------
 -----------------------------------------------------
                              (INCLUDING ZIP CODE)
 
- ------------------------------------------------------
 
IMPORTANT:  THIS LETTER OR A FACSIMILE HEREOF (TOGETHER WITH THE CERTIFICATES
FOR OLD CERTIFICATES OR A BOOK-ENTRY CONFIRMATION AND ALL OTHER REQUIRED
DOCUMENTS OR THE NOTICE OF GUARANTEED DELIVERY) MUST BE RECEIVED BY THE EXCHANGE
AGENT PRIOR TO 5:00 P.M., NEW YORK CITY TIME, ON THE EXPIRATION DATE.
 
                PLEASE READ THIS LETTER OF TRANSMITTAL CAREFULLY
                        BEFORE COMPLETING ANY BOX ABOVE.
 
                                        7
<PAGE>   8
 
<TABLE>
<S>                                                       <C>
PLEASE SIGN HERE
(TO BE COMPLETED BY ALL TENDERING HOLDERS)
(COMPLETE ACCOMPANYING SUBSTITUTE FORM W-9)
 
- ---------------------------------------------------       ---------------------------------------------------
(SIGNATURE(S) OF OWNER(S))
 
Date: --------------------------------------------        Date: --------------------------------------------
Area Code and Telephone Number:
- -------------------------------------------------------------------------------------------------------------
</TABLE>
 
     If a holder is tendering any Old Certificates, this Letter must be signed
by the registered holder(s) as the name(s) appear(s) on the certificate(s) for
the Old Certificates or by any person(s) authorized to become registered
holder(s) by endorsements and documents transmitted herewith. If signature is by
a trustee, executor, administrator, guardian, officer or other person acting in
a fiduciary or representative capacity, please set forth full title. See
Instruction 3.
 
Name(s):
- --------------------------------------------------------------------------------
                             (PLEASE TYPE OR PRINT)
 
Capacity:
- --------------------------------------------------------------------------------
 
Address:
- --------------------------------------------------------------------------------
 
- --------------------------------------------------------------------------------
                              (INCLUDING ZIP CODE)
 
                              SIGNATURE GUARANTEE
                         (IF REQUIRED BY INSTRUCTION 3)
 
Authorized Signature:
- --------------------------------------------------------------------------------
Title:
- --------------------------------------------------------------------------------
Name and Firm:
- --------------------------------------------------------------------------------
Dated:
- --------------------------------------------------------------------------------
 
                                        8
<PAGE>   9
 
                                  INSTRUCTIONS
 
     Forming Part of the Terms and Conditions of the Offer to Exchange Pass
Through Certificates, Series 1998-1, which have been registered under the
Securities Act of 1933, as amended, for any and all outstanding Pass Through
Certificates, Series 1998-1.
 
1.  DELIVERY OF THIS LETTER AND OLD CERTIFICATES; GUARANTEED DELIVERY
    PROCEDURES.
 
     This Letter is to be completed by holders of Old Certificates if
certificates are to be forwarded herewith or if tenders are to be made pursuant
to the procedures for delivery by book-entry transfer set forth in "The Exchange
Offer -- Book-Entry Transfer" section of the Prospectus. Certificates for all
physically tendered Old Certificates, or Book-Entry Confirmation, as the case
may be, as well as a properly completed and duly executed Letter of Transmittal
(or facsimile thereof) and any other documents required by this Letter, must be
received by the Exchange Agent at the address set forth herein on or prior to
the Expiration Date, or the tendering holder must comply with the guaranteed
delivery procedures set forth below. Old Certificates tendered hereby must be in
denominations of $1,000 and any integral multiple thereof.
 
     Holders who are DTC Participants tendering by book-entry transfer must
execute such tender through DTC's ATOP system. A Holder using ATOP should
transmit its acceptance to DTC on or prior to the Expiration Date. DTC will
verify such acceptance, execute a book-entry transfer of the tendered Old
Certificates into the Exchange Agent's account at DTC and then send to the
Exchange Agent a Book-Entry Confirmation, including an Agent's Message
confirming that DTC has received an express acknowledgment from such Holder that
such Holder has received and agrees to be bound by this Letter of Transmittal
and that the Trust and the Company may enforce this Letter of Transmittal
against such Holder. The Book-Entry Confirmation must be received by the
Exchange Agent in order for the tender relating thereto to be effective.
Book-entry transfer to DTC in accordance with DTC's procedure does not
constitute delivery of the Book-Entry Confirmation to the Exchange Agent.
 
     Holders of Old Certificates whose certificates for Old Certificates are not
immediately available or who cannot deliver their certificates and all other
required documents to the Exchange Agent on or prior to the Expiration Date, or
who cannot complete the procedure for book-entry transfer on a timely basis, may
tender their Old Certificates pursuant to the guaranteed delivery procedures set
forth in "The Exchange Offer -- Guaranteed Delivery Procedures" section of the
Prospectus. Pursuant to such procedures, (i) such tender must be made through an
Eligible Institution (as defined below), (ii) prior to the Expiration Date, the
Exchange Agent must receive from such Eligible Institution a properly completed
and duly executed Letter of Transmittal (or facsimile thereof) and Notice of
Guaranteed Delivery, substantially in the form provided by the Company (by
facsimile transmission, mail or hand delivery), setting forth the name and
address of the holder of Old Certificates and the amount of Old Certificates
tendered, stating that the tender is being made thereby and guaranteeing that
within three New York Stock Exchange ("NYSE") trading days after the date of
execution of the Notice of Guaranteed Delivery, the certificates for all
physically tendered Old Certificates, or a Book-Entry Confirmation, as the case
may be, and any other documents required by this Letter will be deposited by the
Eligible Institution with the Exchange Agent, and (iii) the certificates for all
physically tendered Old Certificates, in proper form for transfer, or Book-Entry
Confirmation, as the case may be, and all other documents required by this
Letter, are received by the Exchange Agent within three NYSE trading days after
the date of execution of the Notice of Guaranteed Delivery.
 
     A Notice of Guaranteed Delivery may be delivered by hand or transmitted by
facsimile or mail to the Exchange Agent, and must include a guarantee by an
Eligible Institution in the form set forth in such Notice. For Old Certificates
to be properly tendered pursuant to the guaranteed delivery procedure, the
Exchange Agent must receive a Notice of Guaranteed Delivery on or prior to the
Expiration Date.
 
     As used herein and in the Prospectus, "Eligible Institution" means a firm
or other entity identified in Rule 17Ad-15 under the Exchange Act as "an
eligible guarantor institution," including (as such terms are
 
                                        9
<PAGE>   10
 
defined therein) (i) a bank, (ii) a broker, dealer, municipal securities broker
or dealer or government securities broker or dealer, (iii) a credit union, (iv)
a national securities exchange, registered securities association or clearing
agency, or (iv) a savings association that is a participant in a Securities
Transfer Association.
 
     THE METHOD OF DELIVERY OF THIS LETTER, THE OLD CERTIFICATES AND ALL OTHER
REQUIRED DOCUMENTS IS AT THE ELECTION AND RISK OF THE TENDERING HOLDERS, BUT THE
DELIVERY WILL BE DEEMED MADE ONLY WHEN ACTUALLY RECEIVED OR CONFIRMED BY THE
EXCHANGE AGENT. IF OLD CERTIFICATES ARE SENT BY MAIL, IT IS SUGGESTED THAT THE
MAILING BE MADE SUFFICIENTLY IN ADVANCE OF THE EXPIRATION DATE TO PERMIT
DELIVERY TO THE EXCHANGE AGENT PRIOR TO 5:00 P.M., NEW YORK CITY TIME, ON THE
EXPIRATION DATE.
 
     See "The Exchange Offer" section of the Prospectus.
 
2.  PARTIAL TENDERS (NOT APPLICABLE TO HOLDERS OF OLD CERTIFICATES WHO TENDER BY
    BOOK-ENTRY TRANSFER).
 
     If less than all of the Old Certificates evidenced by a submitted
certificate are to be tendered, the tendering holder(s) should fill in the
aggregate principal amount of Old Certificates to be tendered in the box above
entitled "Description of Old Certificates -- Principal Amount Tendered." A
reissued certificate representing the balance of nontendered Old Certificates
will be sent to such tendering holder, unless otherwise provided in the
appropriate box on this Letter, promptly after the Expiration Date. All of the
Old Certificates delivered to the Exchange Agent will be deemed to have been
tendered unless otherwise indicated.
 
3.  SIGNATURES OF THIS LETTER; BOND POWERS AND ENDORSEMENTS; GUARANTEE OF
    SIGNATURES.
 
     If this Letter is signed by the registered holder of the Old Certificates
tendered hereby, the signature must correspond exactly with the name as written
on the face of the certificates without any change whatsoever.
 
     If any tendered Old Certificates are owned of record by two or more joint
owners, all such owners must sign this Letter.
 
     If any tendered Old Certificates are registered in different names on
several certificates, it will be necessary to complete, sign and submit as many
separate copies of this Letter as there are different registrations of
certificates.
 
     When this Letter is signed by the registered holder of the Old Certificates
specified herein and tendered hereby, no endorsements of certificates or
separate bond powers are required. If, however, the New Certificates are to be
issued, or any untendered Old Certificates are to be reissued, to a person other
than the registered holder, then endorsements of any certificates transmitted
hereby or separate bond powers are required. Signatures on such certificates
must be guaranteed by an Eligible Institution.
 
     If this Letter is signed by a person other than the registered holder of
any certificates specified herein, such certificates must be endorsed or
accompanied by appropriate bond powers, in either case signed exactly as the
name of the registered holder appears on the certificates and the signatures on
such certificates must be guaranteed by an Eligible Institution.
 
     If this Letter or any certificates or bond powers are signed by trustees,
executors, administrators, guardians, attorneys-in-fact, officers of
corporations or others acting in a fiduciary or representative capacity, such
persons should so indicate when signing, and, unless waived by the Company,
proper evidence satisfactory to the Company of their authority to so act must be
submitted.
 
     Endorsements on certificates for Old Certificates or signatures on bond
powers required by this Instruction 3 must be guaranteed by an Eligible
Institution.
 
                                       10
<PAGE>   11
 
     Signatures on this Letter need not be guaranteed by an Eligible
Institution, provided the Old Certificates are tendered: (i) by a registered
holder of Old Certificates (which term, for purposes of the Exchange Offer,
includes any participant in the Book-Entry Transfer Facility system whose name
appears on a security position listing as the holder of such Old Certificates)
tendered who has not completed the box entitled "Special Issuance Instructions"
or "Special Delivery Instructions" on this Letter, or (ii) for the account of an
Eligible Institution.
 
4.  SPECIAL ISSUANCE AND DELIVERY INSTRUCTIONS.
 
     Tendering holders of Old Certificates should indicate in the applicable box
the name and address to which New Certificates issued pursuant to the Exchange
Offer and/or substitute certificates evidencing Old Certificates not exchanged
are to be issued or sent, if different from the name or address of the person
signing this Letter. In the case of issuance in a different name, the employer
identification or social security number of the person named must also be
indicated. A holder of Old Certificates tendering Old Certificates by book-entry
transfer may request that Old Certificates not exchanged be credited to such
account maintained at the Book-Entry Transfer Facility as such holder of Old
Certificates may designate hereon. If no such instructions are given, such Old
Certificates not exchanged will be returned to the name or address of the person
signing this Letter.
 
5.  TAX IDENTIFICATION NUMBER.
 
     Federal income tax law generally requires that a tendering holder whose Old
Certificates are accepted for exchange must provide the Exchange Agent with such
Holder's correct Taxpayer Identification Number ("TIN") on Substitute Form W-9
below, which, in the case of a tendering holder who is an individual, is his or
her social security number. If a tendering holder does not provide the Exchange
Agent with its current TIN or an adequate basis for an exemption, such tendering
holder may be subject to backup withholding in an amount equal to 31% of all
reportable payments made after the exchange. If withholding results in an
overpayment of taxes, a refund may be obtained.
 
     Exempt holders of Old Certificates (including, among others, all
corporations and certain foreign individuals) are not subject to these backup
withholding and reporting requirements. See the enclosed Guidelines of
Certification of Taxpayer Identification Number on Substitute Form W-9 (the "W-9
Guidelines") for additional instructions.
 
     To prevent backup withholding, each tendering holder of Old Certificates
must provide its correct TIN by completing the "Substitute Form W-9" set forth
below, certifying that the TIN provided is correct (or that such holder is
awaiting a TIN) and that (i) the holder is exempt from backup withholding, (ii)
the holder has not been notified by the Internal Revenue Service that such
holder is subject to a backup withholding as a result of a failure to report all
interest or dividends or (iii) the Internal Revenue Service has notified the
holder that such holder is no longer subject to backup withholding. If the
tendering holder of Old Certificates is a nonresident alien or foreign entity
not subject to backup withholding, such holder must give the Exchange Agent a
completed Form W-8, Certificate of Foreign Status. These forms may be obtained
from the Exchange Agent. If the Old Certificates are in more than one name or
are not in the name of the actual owner, such holder should consult the W-9
Guidelines for information on which TIN to report. If such holder does not have
a TIN, such holder should consult the W-9 Guidelines for instructions on
applying for a TIN, check the box in Part 2 of the Substitute Form W-9 and write
"applied for" in lieu of its TIN. Note: checking this box and writing "applied
for" on the form means that such holder has already applied for a TIN or that
such holder intends to apply for one in the near future. If such holder does not
provide its TIN to the Exchange Agent within 60 days, backup withholding will
begin and continue until such holder furnishes its TIN to the Exchange Agent.
 
6.  TRANSFER TAXES.
 
     The Company will pay all transfer taxes, if any, applicable to the transfer
of Old Certificates to it or its order pursuant to the Exchange Offer. If,
however, New Certificates and/or substitute Old Certificates
 
                                       11
<PAGE>   12
 
not exchanged are to be delivered to, or are to be registered or issued in the
name of, any person other than the registered holder of the Old Certificates
tendered hereby, or if tendered Old Certificates are registered in the name of
any person other than the person signing this Letter, or if a transfer tax is
imposed for any reason other than the transfer of Old Certificates to the
Company or its order pursuant to the Exchange Offer, the amount of any such
transfer taxes (whether imposed on the registered holder or any other persons)
will be payable by the tendering holder. If satisfactory evidence of payment of
such taxes or exemption therefrom is not submitted herewith, the amount of such
transfer taxes will be billed directly to such tendering holder.
 
     Except as provided in this Instruction 6, it is not necessary for transfer
tax stamps to be affixed to the Old Certificates specified in this Letter.
 
7.  WAIVER OF CONDITIONS.
 
     The Company reserves the absolute right to waive satisfaction of any or all
conditions enumerated in the Prospectus.
 
8.  NO CONDITIONAL TENDERS.
 
     No alternative, conditional, irregular or contingent tenders will be
accepted. All tendering holders of Old Certificates, by execution of this
Letter, shall waive any right to receive notice of the acceptance of their Old
Certificates for exchange. Neither the Company, the Exchange Agent nor any other
person is obligated to give notice of any defect or irregularity with respect to
any tender of Old Certificates nor shall any of them incur any liability for
failure to give any such notice.
 
9.  MUTILATED, LOST, STOLEN OR DESTROYED OLD CERTIFICATES.
 
     Any holder whose Old Certificates have been mutilated, lost, stolen or
destroyed should contact the Exchange Agent at the address indicated above for
further instructions.
 
10.  REQUESTS FOR ASSISTANCE OR ADDITIONAL COPIES.
 
     Questions relating to the procedure for tendering, as well as requests for
additional copies of the Prospectus and this Letter, may be directed to the
Exchange Agent, at the address and telephone number indicated above.
 
                                       12
<PAGE>   13
 
                    TO BE COMPLETED BY ALL TENDERING HOLDERS
 
                              (SEE INSTRUCTION 5)
 
               GIVE FORM TO THE REQUESTER. DO NOT SEND TO THE IRS
 
<TABLE>
<S>                                <C>                                  <C>
- -----------------------------------------------------------------------------------------------------------
 
 SUBSTITUTE                         PART I -- TAXPAYER IDENTIFICATION NUMBER (TIN)
 FORM W-9
 
                                    ----------------------------------  ----------------------------------
                                                                        LIST ACCOUNT NUMBERS HERE
                                                                        (OPTIONAL)
                                    ----------------------------------
 
                                    PART II -- FOR PAYEE EXEMPT FROM BACKUP WITHHOLDING
                                    (SEE THE W-9 GUIDELINES)
 
                                   Social Security Number
                                   ---------------------------------------------
 
                                   Or Employer Identification Number
                                   ---------------------------------------------
                                    Enter your TIN in the appropriate box. For individuals, this is your
                                    social security number (SSN). For sole proprietors or resident aliens,
                                    see the W-9 Guidelines. For other entities, it is your employer
                                    identification number (EIN). If you do not have a number, see the W-9
                                    Guidelines. NOTE: If the account is in more than one name, see the
                                    chart in the W-9 Guidelines for guidance on whose number to enter.
 Please Print or Type
                                   ------------------------------------------------------------------------
                                   NAME (IF A JOINT ACCOUNT OR YOU CHANGED YOUR NAME, SEE THE W-9
                                   GUIDELINES)
 
                                   ------------------------------------------------------------------------
                                      BUSINESS NAME, IF DIFFERENT FROM ABOVE. (SEE THE W-9 GUIDELINES.)
                                    Please check the appropriate box:   [ ] Individual/Sole Proprietor
                                                                        [ ] Corporation
                                                                        [ ] Partnership
                                                                        [ ] Other
 
                                    -----------------------------------------------------------------------
                                   -----------------------------------------------------------------------
                                    ADDRESS (NUMBER, STREET, APT. OR SUITE NO.).
                                    REQUESTER'S NAME AND ADDRESS (OPTIONAL)
 
                                   ------------------------------------------------------------------------
                                   CITY, STATE AND ZIP CODE
 ----------------------------------------------------------------------------------------------------------
                                    PART III -- CERTIFICATION
                                    Under penalties of perjury, I certify that;
                                    1.  The number shown on this form is my correct taxpayer identification
                                    (or I am waiting for a number to be issued to me), and
                                    2.  I am not subject to backup withholding because: (a) I am exempt
                                    from backup withholding, or (b) I have not been notified by the
                                    Internal Revenue Service that I am subject to backup withholding as a
                                    result of a failure to report all interest or dividends, or (c) the IRS
                                    has notified me that I am no longer subject to backup withholding.
                                   ------------------------------------------------------------------------
                                    CERTIFICATION INSTRUCTIONS. You must cross out item 2 above if you have
 (REV. DECEMBER 1996)               been notified by the IRS that you are currently subject to backup
 DEPARTMENT OF THE TREASURY         withholding because you have failed to report all interest or dividends
 INTERNAL REVENUE SERVICE           on your tax return. For real estate transactions, item 2 does not
 REQUEST FOR TAXPAYER               apply. For mortgage interest paid, the acquisition or abandonment of
 IDENTIFICATION NUMBER              secured property, cancellation of debt, contributions to an individual
 AND CERTIFICATION                  retirement arrangement (IRA), and generally payments other than
                                    interest and dividends, you are not required to sign the Certification,
                                    but you must provide your correct TIN. (Also, see the W-9 Guidelines.)
                                    SIGN HERE:
                                   ------------------------------------------------------------------------
                                    SIGNATURE                           DATE
 ----------------------------------------------------------------------------------------------------------
</TABLE>
 
                                       13

<PAGE>   1
 
                                                                    EXHIBIT 99.2
 
                         NOTICE OF GUARANTEED DELIVERY
                                      FOR
                          AMERICA WEST AIRLINES, INC.
                    PASS THROUGH CERTIFICATES, SERIES 1998-1
 
     This form or one substantially equivalent hereto must be used to accept the
Exchange Offer of America West Airlines, Inc. (the "Company") made pursuant to
the Prospectus, dated             , 1999 (the "Prospectus"), and the enclosed
Letter of Transmittal (the "Letter of Transmittal") if certificates for Old
Certificates are not immediately available or if the procedure for book-entry
transfer cannot be completed on a timely basis or time will not permit all
required documents to reach Wilmington Trust Company (the "Exchange Agent")
prior to 5:00 P.M., New York City time, on the Expiration Date of the Exchange
Offer. Such form may be delivered or transmitted by facsimile transmission, mail
or hand delivery to the Exchange Agent as set forth below. In addition, in order
to utilize the guaranteed delivery procedure to tender Old Certificates pursuant
to the Exchange Offer, a completed, signed and dated Letter of Transmittal (or
facsimile thereof) must also be received by the Exchange Agent prior to 5:00
P.M., New York City time, on the Expiration Date. Capitalized terms not defined
herein are defined in the Prospectus.
 
             DELIVERY TO: WILMINGTON TRUST COMPANY, EXCHANGE AGENT
 
<TABLE>
<S>                                            <C>
        By Mail or Overnight Delivery:                            By Hand:
           Wilmington Trust Company                       Wilmington Trust Company
           1100 North Market Street                 1105 North Market Street, 1st Floor
       Wilmington, Delaware 19890-0001                   Wilmington, Delaware 19890
           Attention: Kristin Long                 Attention: Corporate Trust Operations
</TABLE>
 
                            Facsimile Transmission:
                                 (302) 651-1079
 
                             Confirm by Telephone:
                                 (302) 651-1562
                                  Kristin Long
 
     Delivery of this instrument to an address other than as set forth above, or
transmission of instructions via facsimile other than as set forth above, will
not constitute a valid delivery.
<PAGE>   2
 
Ladies and Gentlemen:
 
     Upon the terms and conditions set forth in the Prospectus and the
accompanying Letter of Transmittal, the undersigned hereby tenders to the
Company the principal amount of Old Certificates set forth below, pursuant to
the guaranteed delivery procedure described in "The Exchange Offer -- Guaranteed
Delivery Procedures" section of the Prospectus.
 
             ------------------------------------------------------
 
   Principal Amount of Old Certificates Tendered:
 
   $
   ----------------------------------------------------
 
   Certificate Nos. (if available):
 
             ------------------------------------------------------
 
             ------------------------------------------------------
 
   If Old Certificates will be delivered by book-entry transfer to The
   Depository Trust Company, provide account number.
 
   The Depository Trust Company
   Account No.
- ------------------------------------------------------
             ------------------------------------------------------
 
   Name(s) of Record Holder(s):
 
   ------------------------------------------------------
 
   ------------------------------------------------------
                              PLEASE PRINT OR TYPE
 
   Address(es):
 
   ------------------------------------------------------
 
   ------------------------------------------------------
 
   Area Code and Telephone Number(s):
 
   ------------------------------------------------------
 
   Signature(s):
 
   ------------------------------------------------------
 
   ------------------------------------------------------
 
   Dated:
- ------------------------------------------------------
 
                 THE ACCOMPANYING GUARANTEE MUST BE COMPLETED.
 
                                        2
<PAGE>   3
 
                                   GUARANTEE
 
                    (NOT TO BE USED FOR SIGNATURE GUARANTEE)
 
     The undersigned, a firm that is a member firm of a registered national
securities exchange or of the National Association of Securities Dealers, Inc.,
a commercial bank or trust company having an office or correspondent in the
United States or any "eligible guarantor" institution within the meaning of Rule
17Ad-15 of the Securities Exchange Act of 1934, as amended, hereby guarantees to
deliver to the Exchange Agent, at one of its addresses set forth above, the
certificates representing all tendered Old Certificates, in proper form for
transfer, or a Book-Entry Confirmation, together with a properly completed and
duly executed Letter of Transmittal (or facsimile thereof), with any required
signature guarantees, and any other documents required by the Letter of
Transmittal within three New York Stock Exchange, Inc. trading days after the
date of execution of this Notice of Guaranteed Delivery.
 
     THE UNDERSIGNED ACKNOWLEDGES THAT IT MUST DELIVER THE LETTER OF TRANSMITTAL
TO THE EXCHANGE AGENT WITHIN THE TIME PERIOD SET FORTH THEREIN AND THAT FAILURE
TO DO SO COULD RESULT IN FINANCIAL LOSS TO THE UNDERSIGNED.
 
<TABLE>
<S>                                                       <C>
Name of Firm ----------------------------------
                                                          ---------------------------------------------------
                                                          AUTHORIZED SIGNATURE
Address: -----------------------------------------        Name: -------------------------------------------
                                                          (PLEASE TYPE OR PRINT)
                                                          Title: --------------------------------------------
- ---------------------------------------------------
Area Code and
Telephone Number: -----------------------------           Date: --------------------------------------------
</TABLE>
 
                                        3

<PAGE>   1
 
                                                                    EXHIBIT 99.3
 
                          AMERICA WEST AIRLINES, INC.
 
                               OFFER TO EXCHANGE
                   PASS THROUGH CERTIFICATES, SERIES 1998-1,
                           WHICH HAVE BEEN REGISTERED
                 UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
                          FOR ANY AND ALL OUTSTANDING
                    PASS THROUGH CERTIFICATES, SERIES 1998-1
 
To: Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees:
 
     Upon and subject to the terms and conditions set forth in the Prospectus,
dated             , 1999 (the "Prospectus"), and the enclosed Letter of
Transmittal (the "Letter of Transmittal"), an offer to exchange (the "Exchange
Offer") the registered Pass Through Certificates, Series 1998-1 (the "New
Certificates") for any and all outstanding Pass Through Certificates, Series
1998-1 (the "Old Certificates") is being made pursuant to such Prospectus. The
Exchange Offer is being made in order to satisfy certain obligations of America
West Airlines, Inc. (the "Company") contained in the Exchange and Registration
Rights Agreement dated as of October 6, 1998, between the Company and the
Initial Purchasers.
 
     The CUSIP numbers for the Old Certificates are as follows: Class A (023654
AK 2), Class B (023654 AL O), and Class C (023654 AM 8).
 
     We are requesting that you contact your clients for whom you hold Old
Certificates regarding the Exchange Offer. For your information and for
forwarding to your clients for whom you hold Old Certificates registered in your
name or in the name of your nominee, or who hold Old Certificates registered in
their own names, we are enclosing the following documents:
 
          1. Prospectus dated                , 1999;
 
          2. The Letter of Transmittal for your use and for the information of
     your clients;
 
          3. A Notice of Guaranteed Delivery to be used to accept the Exchange
     Offer if certificates for Old Certificates are not immediately available or
     time will not permit all required documents to reach the Exchange Agent
     prior to the Expiration Date (as defined below) or if the procedure for
     book-entry transfer cannot be completed on a timely basis; and
 
          4. A form of letter which may be sent to your clients for whose
     account you hold Old Certificates registered in your name or the name of
     your nominee, with space provided for obtaining such clients' instructions
     with regard to the Exchange Offer.
 
     Your prompt action is requested. The Exchange Offer will expire at 5:00
p.m., New York City time, on             , 1999 (the "Expiration Date") (30
calendar days following the commencement of the Exchange Offer), unless extended
by the Company. The Old Certificates tendered pursuant to the Exchange Offer may
be withdrawn at any time before the Expiration Date.
 
     To participate in the Exchange Offer, a duly executed and properly
completed Letter of Transmittal (or facsimile thereof), with any required
signature guarantees and any other required documents, should be sent to the
Exchange Agent and certificates representing the Old Certificates should be
delivered to the Exchange Agent, all in accordance with the instructions set
forth in the Letter of Transmittal and the Prospectus.
<PAGE>   2
 
     Please note that brokers, dealers, commercial banks, trust companies and
other nominees who hold Old Certificates through The Depository Trust Company
("DTC") must effect tenders by book-entry transfer through DTC's Automated
Tender Offer Program ("ATOP").
 
     If holders of Old Certificates wish to tender, but it is impracticable for
them to forward their certificates for Old Certificates prior to the expiration
of the Exchange Offer or to comply with the book-entry transfer procedures on a
timely basis, a tender may be effected by following the guaranteed delivery
procedures described in the Prospectus under "The Exchange Offer -- Guaranteed
Delivery Procedures".
 
     Additional copies of the enclosed material may be obtained from Wilmington
Trust Company, the Exchange Agent, at 1100 North Market Street, Wilmington,
Delaware 19890-0001, Attention: Kristin Long, phone (302) 651-1562 and facsimile
(302) 651-1079.
 
                                                         AMERICA WEST AIRLINES,
INC.
 
                                        2

<PAGE>   1
 
                                                                    EXHIBIT 99.4
 
                          AMERICA WEST AIRLINES, INC.
 
                               OFFER TO EXCHANGE
                   PASS THROUGH CERTIFICATES, SERIES 1998-1,
                           WHICH HAVE BEEN REGISTERED
                 UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
                          FOR ANY AND ALL OUTSTANDING
                    PASS THROUGH CERTIFICATES, SERIES 1998-1
 
To Our Clients:
 
     Enclosed for your consideration is a Prospectus of America West Airlines,
Inc., a Delaware corporation (the "Company" or "America West"), dated
            , 1999 (the "Prospectus"), and the enclosed Letter of Transmittal
(the "Letter of Transmittal") relating to the offer to exchange (the "Exchange
Offer") the registered Pass Through Certificates, Series 1998-1 (the "New
Certificates") for any and all outstanding Pass Through Certificates, Series
1998-1 (the "Old Certificates"), upon the terms and subject to the conditions
described in the Prospectus. The Exchange Offer is being made in order to
satisfy certain obligations of Continental contained in the Exchange and
Registration Rights Agreement dated as of October 6, 1998, between the Company
and the Initial Purchasers.
 
     The CUSIP numbers for the Old Certificates are as follows: Class A (023654
AK 2), Class B (023654 AL O), and Class C (023654 AM 8).
 
     This material is being forwarded to you as the beneficial owner of the Old
Certificates carried by us in your account but not registered in your name. A
tender of such Old Certificates may only be made by us as the holder of record
and pursuant to your instructions.
 
     Accordingly, we request instructions as to whether you wish us to tender on
your behalf the Old Certificates held by us for your account, pursuant to the
terms and conditions set forth in the enclosed Prospectus and Letter of
Transmittal.
 
     Your instructions should be forwarded to us as promptly as possible in
order to permit us to tender the Old Certificates on your behalf in accordance
with the provisions of the Exchange Offer. The Exchange Offer will expire at
5:00 p.m., New York City time, on             , 1999 (the "Expiration Date") (30
calendar days following the commencement of the Exchange Offer), unless extended
by the Company. Any Old Certificates tendered pursuant to the Exchange Offer may
be withdrawn at any time before 5:00 p.m., New York City time on the Expiration
Date.
 
     Your attention is directed to the following:
 
          1.  The Exchange Offer is for any and all Old Certificates.
 
          2.  The Exchange Offer is subject to certain conditions set forth in
     the Prospectus in the section captioned "The Exchange Offer -- Conditions".
 
          3.  Any transfer taxes incident to the transfer of Old Certificates
     from the holder to the Company will be paid by the Company, except as
     otherwise provided in the Instructions in the Letter of Transmittal.
 
          4.  The Exchange Offer expires at 5:00 p.m., New York City time, on
     the Expiration Date unless extended by the Company.
<PAGE>   2
 
     If you wish to have us tender your Old Certificates, please so instruct us
by executing and returning to us the instruction form set forth below. The
Letter of Transmittal is furnished to you for information only and may not be
used directly by you to tender Old Certificates.
 
                INSTRUCTIONS WITH RESPECT TO THE EXCHANGE OFFER
 
     The undersigned acknowledge(s) receipt of your letter enclosing the
Prospectus, dated             , 1998, of America West Airlines, Inc., a Delaware
corporation, and the related specimen Letter of Transmittal.
 
- --------------------------------------------------------------------------------
 
     This will instruct you to tender the number of Old Certificates indicated
below held by you for the account of the undersigned, pursuant to the terms and
conditions set forth in the Prospectus and the related Letter of Transmittal.
(Check one).
 
<TABLE>
<S>   <C>          <C>
Box 1     [ ]      Please tender my Old Certificates held by you for my
                   account. If I do not wish to tender all of the Old
                   Certificates held by you, I have identified on a signed
                   schedule attached hereto the number of Old Certificates I do
                   not wish tendered.
 
Box 2     [ ]      Please do not tender any Old Certificates held by you for my
                   account.
</TABLE>
 
- --------------------------------------------------------------------------------
 
<TABLE>
<S>                                          <C>
 
Date                , 199                    -----------------------------------------------------
                                                                 SIGNATURE(S)
                                             -----------------------------------------------------
                                             -----------------------------------------------------
                                                           PLEASE PRINT NAME(S) HERE
                                             -----------------------------------------------------
                                                          AREA CODE AND TELEPHONE NO.
</TABLE>
 
     UNLESS A SPECIFIC CONTRARY INSTRUCTION IS GIVEN IN THE SPACE PROVIDED, YOUR
                                  SIGNATURE(S)
  HEREON SHALL CONSTITUTE AN INSTRUCTION TO US TO TENDER ALL OLD CERTIFICATES.
 
                                        2


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