Document:

<PAGE>   1

                                   EXHIBIT 4.9

                                                                  EXECUTION COPY

                          PASS THROUGH TRUST AGREEMENT

                            Dated as of May 17, 2001

                                     between

                           AMERICA WEST AIRLINES, INC.

                                       and

                            WILMINGTON TRUST COMPANY,

                                   as Trustee

           America West Airlines Pass Through Trust, Series 2001-1D-S

               Initial Pass Through Certificates, Series 2001-1D-S
              Exchange Pass Through Certificates, Series 2001-1D-S
<PAGE>   2
Reconciliation and tie between America West Airlines Pass Through Trust
Agreement, Series 2001-1D-S dated as of May 17, 2001, 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.................................................    14
         Section 1.03.     Form of Documents Delivered to Trustee...............................................    14
         Section 1.04.     Directions of Certificateholders.....................................................    15

ARTICLE II  ACQUISITION OF TRUST PROPERTY.......................................................................    16
         Section 2.01.     Acquisition of Trust Property........................................................    16
         Section 2.02.     Acceptance by the Trustee............................................................    16
         Section 2.03.     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..........................................................    23
         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.................................................    27
         Section 3.12.     ERISA Restrictive Legend.............................................................    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.................................................    34
         Section 6.03.     Judicial Proceedings Instituted by Trustee; Trustee May Bring
                           Suit.................................................................................    35
         Section 6.04.     Control by Certificateholders........................................................    35
         Section 6.05.     Waiver of Past Defaults..............................................................    35
</TABLE>
<PAGE>   4
<TABLE>
<CAPTION>
SECTION                                                                                                            PAGE
<S>                                                                                                                <C>
         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.......................    45
         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

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

</TABLE>

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

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

                                      iii
<PAGE>   6
                          PASS THROUGH TRUST AGREEMENT

                  This PASS THROUGH TRUST AGREEMENT, dated as of May 17, 2001
(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 2001-1D-S and the
$45,000,000 America West Airlines Pass Through Trust, Series 2001-1D-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 of all or a portion 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, 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 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 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;

                  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
<PAGE>   7
                                       2

"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

                  (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".
<PAGE>   8
                                       3

                  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 Pass Through Trust Agreement 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 Industries.

                  Break Amount: Has the meaning specified in the Indentures.

                  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.

                  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 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).
<PAGE>   9
                                       4

                  Certificate Purchase Agreement: Means the Purchase Agreement
         dated May 10, 2001 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.

                  Clearstream: Means Clearstream Banking, societe anonyme,
         organized under Luxembourg law (formerly known as Cedelbank) or any
         successor thereto.

                  Class C Certificateholder: Has the meaning specified in the
         Intercreditor Agreement.

                  Class C Certificates: Has the meaning specified in the
         Intercreditor Agreement.

                  Class C Trust Agreement: Has the meaning specified in the
         Intercreditor Agreement.

                  Class C Trustee: Has the meaning specified in the
         Intercreditor Agreement.

                  Class G Certificateholder: Has the meaning specified in the
         Intercreditor Agreement.

                  Class G Certificates: Has the meaning specified in the
         Intercreditor Agreement.

                  Class G Trust Agreement: Has the meaning specified in the
         Intercreditor Agreement.

                  Class G Trustee: Has the meaning specified in the
         Intercreditor Agreement.

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

                  Delivery Period Termination Date: Has the meaning specified in
         the Related Pass Through Trust Agreement.
<PAGE>   10
                                       5

                  Deposits: Has the meaning specified in the Deposit Agreement.

                  Deposit Agreement: Means the Deposit Agreement dated as of May
         17, 2001 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 Citibank, N.A.

                  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, 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 May 17, 2001 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.
<PAGE>   11
                                       6

                  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 October 2, 2005.

                  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).

                  Interest Period: Means the period commencing on and including
         the Issuance Date and ending on but excluding the next succeeding
         Regular Distribution Date, and thereafter, each successive period
         commencing on and including the last day of the immediately preceding
         Regular Distribution Date and ending on but excluding the next
         succeeding Regular Distribution Date.

                  Initial Certificates: Means the "Initial Certificates" issued
         and authenticated under the Related Pass Through Trust Agreement, and
         any certificates issued and
<PAGE>   12
                                       7

         authenticated thereunder substantially in the form of Exhibit A thereto
         other than the Exchange Certificates.

                  Initial Purchasers: Means Salomon Smith Barney Inc., Deutsche
         Banc Alex. Brown Inc., Mizuho International plc, Banc One Capital
         Markets, Inc. and Tokyo-Mitsubishi International plc.

                  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 May 17, 2001 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) the Related Other Pass Through Trust Agreements, the Policy
         Provider 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 Provider: Means, initially, Westdeutsche Landesbank
         Girozentrale, 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 May 17, 2001 among the Related Trustee (and after the
         Transfer Date, the Trustee), the
<PAGE>   13
                                       8

         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 May 10,
         2000 relating to the offering of the Certificates and the other
         certificates issued 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 LLP, 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 the other America
         West Airlines 2001-1 Pass Through Trust Agreements relating to the
         America West Airlines Pass Through Trust, Series 2001-1G-S and the
         America West Airlines Pass Through Trust, Series 2001-1C-S, dated the
         date hereof.

                  Other Trustees: Means the trustee 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 2001-1G-S and the America West Airlines Pass Through
         Trust, Series 2001-1C-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
<PAGE>   14
                                       9

                           (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 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.

                  Payment Date: Means April 2 and October 2 commencing on or
         after October 2, 2001.

                  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.

                  Policy: Has the meaning specified in the Intercreditor
         Agreement.

                  Policy Provider: Has the meaning specified in the
         Intercreditor Agreement.

                  Policy Provider Agreement: Has the meaning specified in the
         Intercreditor Agreement.

                  Policy Provider Default: Has the meaning specified in the
         Intercreditor Agreement.
<PAGE>   15
                                       10

                  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, Break Amount or premium thereon or
         reimbursement of any costs or expenses incurred in connection
         therewith. 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.

                  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 May 17, 2001, 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
<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 Other Pass Through Trust Agreements: Means the "Other
         Pass Through Trust Agreements" as defined in the Related Pass Through
         Trust Agreement.

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

                  Related Other Trust: 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 the America West Airlines Pass Through
         Trust, Series 2001-1D-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.

                  Related Trust: Means the America West Pass Through Trust,
         Series 2001-1D-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.
<PAGE>   17
                                       12

                  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
         any payment of principal or interest on or in respect of 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, 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, interest or Break Amount, if any, 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.

                  Six-Month LIBOR: Has the meaning specified in the Deposit
         Agreement and the Indentures.

                  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 or other amounts
         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).
<PAGE>   18
                                       13

                  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 Trust, under the
         Intercreditor Agreement, the Escrow Agreement and the Note Purchase
         Agreement, 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, 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 in the Related Pass Through Trust 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, 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
<PAGE>   19
                                       14

         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

                  (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
<PAGE>   20
                                       15

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
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,
<PAGE>   21
                                       16

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. (a) 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 "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 the 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,
<PAGE>   22
                                       17

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 including
without limitation purchasing any Equipment Note issued in connection with the
redemption of outstanding Equipment Notes under any Indenture 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 "Initial Pass Through Certificates, Series 2001-1D-S" and the
Exchange Certificates constituting Certificates shall be known as the "Exchange
Pass Through Certificates, Series 2001-1D-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 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
<PAGE>   23
                                       18

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 $$45,000,000.

                  (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 a nominee 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 a nominee 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 Clearstream. 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 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"). 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
<PAGE>   24
                                       19

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 Pass Through Trust Agreement 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 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:

         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
<PAGE>   25
                                       20

         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 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.
<PAGE>   26
                                       21

         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 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
<PAGE>   27
                                       22

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, 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.
<PAGE>   28
                                       23

                  (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.

                  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:
<PAGE>   29
                                       24

                           (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 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
<PAGE>   30
                                       25

                  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 Clearstream.

                  (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 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
<PAGE>   31
                                       26

         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 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.
<PAGE>   32
                                       27

                  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.

                  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
<PAGE>   33
                                       28

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 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,
<PAGE>   34
                                       29

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.

                  (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
<PAGE>   35
                                       30

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, interest and Break Amount, if any,

                  (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, or Break Amount, 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 or Break Amount
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 Break Amount, if any;

                  (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;
<PAGE>   36
                                       31

                  (vi) the Pool Balance and the Pool Factor; and

                  (vii) the Six-Month LIBOR rate and the resulting interest
         rates payable on the Certificates for the current and immediately
         preceding Interest Periods.

                  With respect to the Certificates registered in the name of
DTC, on the Record Date prior to each Distribution Date, the Trustee will
request that DTC post on its internet bulletin board 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.

                  (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 56 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 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
<PAGE>   37
                                       32

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, 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
<PAGE>   38
                                       33

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, with ten days' written notice to the Trustee and each
Certificateholder, 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
         within 180 days after the occurrence and during the continuation of a
         Triggering Event, each Certificateholder shall have the right to
         purchase, for the purchase price set forth in the Class G Trust
         Agreement, all, but not less than all, of the Class G Certificates upon
         ten days' written notice to the Class G 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 G 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 G Certificates pursuant to this
         Section 6.01(b); and

                  (ii) at any time within 180 days after the occurrence and
         during the continuation of a Triggering Event, each Certificateholder
         shall have the right to purchase, for the purchase price set forth in
         the Class C Trust Agreement, all but not less than all, of the Class C
         Certificates upon ten days' written notice to the Class C 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 C 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, the such other Certificateholder shall lose its right to
         purchase the Class C Certificates pursuant to Section 6.01(b).

                  (iii) By acceptance of its Certificate, each Certificateholder
         agrees that at any time after 180 days have elapsed since the
         occurrence of a Triggering Event that is continuing, regardless of
         whether the Certificateholders exercise their right to purchase
<PAGE>   39
                                       34

         the Class G Certificates pursuant to clause (b)(i) above, the Policy
         Provider, if it is then the Controlling Party, shall have the right
         (except in the event of a Policy Provider Default) to purchase all, but
         not less than all, of the Class G Certificates upon ten days' written
         notice to the Class G Trustee and the Class G Certificateholders.

                  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 and the Class G
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). 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.

                  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 or Break Amount, if any, 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 or Break Amount, if any, 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 or Break Amount, if any, 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 continuation 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>   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, interest or Break
Amount, if any, 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;
<PAGE>   44
                                       39

                  (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 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:
<PAGE>   45
                                       40

                  (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
         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
<PAGE>   46
                                       41

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 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
<PAGE>   47
                                       42

                  (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.

                  (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
<PAGE>   48
                                       43

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 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
<PAGE>   49
                                       44

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.

                  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.
<PAGE>   50
                                       45

                  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, and (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
<PAGE>   51
                                       46

                  (e)      this 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,
interest, Break Amount, if any, 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.

                  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
<PAGE>   52
                                       47

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 or the Registration Rights Agreement 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 or the Registration Rights Agreement; 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 or the
         Registration Rights Agreement; or

                  (3) to correct or supplement any provision in this Agreement,
         the Intercreditor Agreement, the Escrow Agreement, the Deposit
         Agreement, the Note Purchase Agreement or the Registration Rights
         Agreement 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
<PAGE>   54
                                       49

         Agreement, the Escrow Agreement, the Deposit Agreement, the Note
         Purchase Agreement, the Intercreditor Agreement or the Registration
         Rights Agreement, 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, 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
<PAGE>   55
                                       50

Certificateholders under this Agreement, the Intercreditor Agreement, 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 or other Trust
         Property 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 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>   56
                                       51

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>   57
                                       52

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 on 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
<PAGE>   58
                                       53

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 Administration
                           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/ Thomas T. Weir
                                    --------------------------------------------
                                       Name:  Thomas T. Weir
                                       Title: Vice President and Treasurer

                                 WILMINGTON TRUST COMPANY,
                                       as Trustee

                                 By:    /s/ W. Chris Sponenberg
                                    --------------------------------------------
                                       Name:  W. Chris Sponenberg
                                       Title: Assistant Vice President
<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 (the "Trust"),
                  Series 2001-1D-S, America West Airlines Pass Through
                  Certificates, Series 2001-1D-S (the "Certificates")

Sirs:

                  In connection with our proposed sale of Certificates
representing a Fractional Undivided Interest, having a face amount of $ ______,
in the Trust, 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.
<PAGE>   63
                                      A-2

                  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 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 2001-1D-S (the "Trust")
                   Pass Through Certificates, Series 2001-1D-S
                              (the "Certificates")

Ladies and Gentlemen:

         In connection with our proposed purchase of Certificates representing a
Fractional Undivided Interest, having a face amount of $[_____], in the Trust,
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 May 17, 2001, 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>   65
                                       D-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 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 COPY

                      REVOLVING CREDIT AGREEMENT (2001-1G)

                            Dated as of May 17, 2001

                                     between

                            WILMINGTON TRUST COMPANY,

                             as Subordination Agent,
                          as agent and trustee for the
                America West Airlines Pass Through Trust 2001-1G,

                                   as Borrower

                      WESTDEUTSCHE LANDESBANK GIROZENTRALE,
                                New York Branch,

                              as Liquidity Provider

                                   Relating to

                America West Airlines Pass Through Trust 2001-1G
 7.10% America West Airlines Enhanced Pass Through Certificates, Series 2001-1G
<PAGE>   2
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                            PAGE
<S>                                                                                                         <C>
ARTICLE I             DEFINITIONS........................................................................    1

         Section 1.01      Certain Defined Terms.........................................................    1

ARTICLE II            AMOUNT AND TERMS OF THE COMMITMENT.................................................    7

         Section 2.01      Advances......................................................................    7

         Section 2.02      Making the Advances...........................................................    7

         Section 2.03      Fees..........................................................................    9

         Section 2.04      Automatic Adjustments and Termination of the Maximum Commitment...............    9

         Section 2.05      Repayments of Interest Advances or the Final Advance..........................   10

         Section 2.06      Repayments of Provider Advances...............................................   10

         Section 2.07      Payments to the Liquidity Provider Under the Intercreditor Agreement..........   11

         Section 2.08      Book Entries..................................................................   11

         Section 2.09      Payments from Available Funds Only............................................   12

         Section 2.10      Extension of Expiry Date......................................................   12

ARTICLE III           OBLIGATIONS OF THE BORROWER........................................................   12

         Section 3.01      Increased Costs...............................................................   12

         Section 3.02      Capital Adequacy..............................................................   13

         Section 3.03      Payments Free of Deductions...................................................   14

         Section 3.04      Payments......................................................................   15

         Section 3.05      Computations..................................................................   15

         Section 3.06      Payment on Non-Business Days..................................................   15

         Section 3.07      Interest......................................................................   16

         Section 3.08      Replacement of Borrower.......................................................   17

         Section 3.09      Funding Loss Indemnification..................................................   17

         Section 3.10      Illegality....................................................................   18

ARTICLE IV            CONDITIONS PRECEDENT...............................................................   18

         Section 4.01      Conditions Precedent to Effectiveness of Section 2.01.........................   18

         Section 4.02      Conditions Precedent to Borrowing.............................................   20
</TABLE>

                                        i
<PAGE>   3
                                TABLE OF CONTENTS
                                   (CONTINUED)

<TABLE>
<CAPTION>
                                                                                                            PAGE
<S>                                                                                                         <C>
ARTICLE V             COVENANTS..........................................................................   20

         Section 5.01      Affirmative Covenants of the Borrower.........................................   20

         Section 5.02      Negative Covenants of the Borrower............................................   20

ARTICLE VI            LIQUIDITY EVENTS OF DEFAULT........................................................   21

         Section 6.01      Liquidity Events of Default...................................................   21

ARTICLE VII           MISCELLANEOUS......................................................................   21

         Section 7.01      Amendments, Etc...............................................................   21

         Section 7.02      Notices, Etc..................................................................   21

         Section 7.03      No Waiver: Remedies...........................................................   22

         Section 7.04      Further Assurances............................................................   22

         Section 7.05      Indemnification: Survival of Certain Provisions...............................   23

         Section 7.06      Liability of the Liquidity Provider...........................................   23

         Section 7.07      Costs.........................................................................   24

         Section 7.08      Binding Effect; Participations................................................   24

         Section 7.09      Severability..................................................................   25

         Section 7.10      GOVERNING LAW.................................................................   26

         Section 7.11      Submission to Jurisdiction: Waiver of Jury Trial; Waiver of Immunity..........   26

         Section 7.12      Execution in Counterparts.....................................................   27

         Section 7.13      Entirety......................................................................   27

         Section 7.14      Headings......................................................................   27

         Section 7.15      LIQUIDITY PROVIDER'S OBLIGATION TO MAKE ADVANCES..............................   27

         Section 7.16      Transfer......................................................................   27
</TABLE>

                                       ii
<PAGE>   4
                     REVOLVING CREDIT AGREEMENT (2001-1G)

      This REVOLVING CREDIT AGREEMENT (2001-1G), dated as of May 17, 2001 (as it
may be amended, supplemented or otherwise modified from time to time in
accordance with the terms hereof, this "Agreement"), 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 G Trust (as defined below) (the
"Borrower"), and WESTDEUTSCHE LANDESBANK GIROZENTRALE, a German banking
institution organized under the laws of the State of North Rhine - Westphalia,
Germany, acting through its New York branch ("West LB" or the "Liquidity
Provider").

                               W I T N E S S E T H

            WHEREAS, pursuant to the Class G Trust Agreement (as defined below),
the Class G Trust is issuing the Class G Certificates; and

            WHEREAS, the Borrower, in order to support the timely payment of a
portion of the interest on the Class G 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 mutual promises contained
herein, 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 Certain Defined Terms. (a) For all purposes of this
Agreement, except as otherwise expressly provided or unless the context
otherwise requires:

                  (i) the terms used herein that are defined in this Article I
      have the meanings assigned to them in this Article I, and include the
      plural as well as the singular;

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

                  (iii) 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

                  (iv) the term "including" means "including without
      limitation".

                                       1.
<PAGE>   5
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

            "Additional Costs" has the meaning specified in Section 3.01.

            "Advance" means an Interest Advance, a Final Advance, a Provider
Advance or an Applied Provider Advance, as the case may be.

            "Applicable Liquidity Rate" has the meaning specified in Section
3.07(g).

            "Applicable Margin" means (x) with respect to any Unpaid Advance or
Applied Provider Advance, 2.25% and (y) with respect to any Unapplied Provider
Advance, 0.35%.

            "Applied Downgrade Advance" has the meaning specified 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 Agreement to be entered into between the Borrower and the trustee of
the Successor Trust, substantially in the form of Exhibit D to the Class G Trust
Agreement.

            "Base Rate" means the rate of interest announced publicly by WestLB
from time to time in New York, New York, as its base rate.

            "Base Rate Advance" means an Advance that bears interest at a rate
based upon the Base Rate.

            "Borrower" has the meaning specified in the recitals to this
Agreement.

            "Borrowing" means the making of Advances requested by delivery of a
Notice of Borrowing.

            "Business Day" means any day (x) other than a Saturday or Sunday or
a day on which commercial banks are authorized or required by law to close in
Phoenix, Arizona, New York, New York or, so long as any Class G Certificate is
outstanding, the city and state in which the Class G Trustee, the Borrower or
any Indenture Trustee maintains its corporate trust office or receives and
disburses funds, and (y) if the applicable Business Day relates to any Advance
or amount bearing interest based on LIBOR, on which dealings are carried on in
the London interbank market.

            "Consent Period" has the meaning specified in Section 2.10.

            "Deposits" has the meaning assigned to such term in the Deposit
Agreement.

                                       2.
<PAGE>   6
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

            "Depositary" means Citibank, N.A.

            "Deposit Agreement" means the Deposit Agreement (2001-1G) dated as
of the date hereof between Wilmington Trust Company, as Escrow Agent and
Citibank, N.A., as Depositary, pertaining to the Class G Certificates, 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) any Taxes imposed on, based on, or
measured by the overall net income, capital, franchises, or receipts (other than
Taxes which are or are in the nature of sales or use Taxes or value added Taxes)
of the Liquidity Provider or any of its Lending Offices, (ii) withholding Taxes
imposed under laws in effect on the date hereof by the United States on payments
to a recipient in the jurisdiction in which the Liquidity Provider's initial
Lending Office is located, (iii) withholding Taxes imposed by the United States
on payments to a recipient in any other jurisdiction to which such Lending
Office is moved if, under the laws in effect at the time of such move, such laws
would require greater withholding of Taxes on payments to such Liquidity
Provider acting from an office in such jurisdiction than would be required on
payments to such Liquidity Provider acting from an office in the jurisdiction
from which such Lending Office was moved, and (iv) 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 able and 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
Taxes.

            "Expiry Date" means May 15, 2002, 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
as of the date hereof among the Trustees, the Liquidity Provider, the liquidity
provider under each Liquidity Facility (other than this Agreement), the Policy
Provider and the Subordination Agent, as the same may be amended, supplemented
or otherwise modified from time to time in accordance with its terms.

                                       3.
<PAGE>   7
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

            "Interest Advance" means an Advance made pursuant to Section
2.02(a).

            "Interest Period" means, with respect to any LIBOR Advance, each of
the following periods:

            (1) 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 (y) the withdrawal of funds from the Class G Cash
      Collateral Account for the purpose of paying interest on the Class G
      Certificates as contemplated by Section 2.06(a) hereof and, in either
      case, ending on the next Regular Distribution Date; and

            (2) 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
Regular Distribution Date following such conversion (in the case of clause (y)
above).

            "Lending Office" means the lending office of the Liquidity Provider,
presently located at New York, New York, or such other lending office as the
Liquidity Provider from time to time shall notify the Borrower as its lending
office hereunder.

            "LIBOR" means, with respect to any Interest Period, the interest
rate per annum at which deposits in United States dollars are offered to prime
banks in the London interbank market as indicated on display page 3750 (British
Bankers Association-LIBOR) of the Dow Jones Markets Service (or such other page
as may replace such display page 3750 for the purpose of displaying London
interbank offered rates for United States dollar deposits) or, if not so
indicated, the average (rounded upwards to the nearest 1/16%), as determined by
the Liquidity Provider, of such rates as indicated on the Reuters Screen LIBO
Page (or such other page as may replace such Reuters Screen LIBO Page for the
purpose of displaying London interbank offered rates for United States dollar
deposits) or, if neither such alternative is indicated, the average (rounded
upwards to the nearest 1/16%), as determined by the Liquidity Provider, of such
rates offered by the London Reference Banks to prime banks in the London
interbank market, in each case at or about 11:00 a.m. (London time) on the day
two Business Days prior to the first day of such Interest Period for deposits of
a duration equal to such Interest Period (or such other period most nearly
corresponding to such period) in an amount substantially equal to the principal
amount of the applicable LIBOR Advance as of the first day of such Interest
Period. The Liquidity Provider will, if necessary, request that each of the
London Reference Banks provide a quotation of its rate. If at least two such
quotations are provided, the rate will be the average of the quotations (rounded
upwards to the nearest 1/100%). If no such quotation can be obtained, the rate
will be the Base Rate.

                                       4.
<PAGE>   8
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

            "LIBOR Advance" means an Advance bearing interest at a rate based
upon LIBOR.

            "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 $100,000,000) or (b) an
America West Bankruptcy Event.

            "Liquidity Indemnitee" means (i) the Liquidity Provider, (ii) the
directors, officers, employees, servants and agents of the Liquidity Provider,
and (iii) the successors and permitted assigns of the persons described in
clauses (i) through (ii), inclusive.

            "Liquidity Provider" has the meaning specified in the recital of
parties to this Agreement.

            "London Reference Banks" means the principal London offices of
Citicorp USA, Inc., The Fuji Bank, Limited, National Westminster Bank plc and
The Industrial Bank of Japan, Limited, or such other bank or banks as may from
time to time be agreed to by America West and the Liquidity Provider.

            "Maximum Available Commitment" shall mean, 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, however,
that following a Provider Advance or a Final Advance, the Maximum Available
Commitment shall be zero.

            "Maximum Commitment" means initially $34,627,729.50, as the same may
be reduced or increased from time to time in accordance with Section 2.04(a).

            "Non-Excluded Tax" has the meaning specified in Section 3.03.

            "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 May 10,
2001 relating to the Certificates, as such Offering Memorandum may be amended or
supplemented.

            "Participating Institution" has the meaning specified in Section
7.08(b).

            "Participation Agreement" means, with respect to each Indenture, the
"Participation Agreement" referred to therein.

                                       5.
<PAGE>   9
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

            "Performing Note Deficiency" means anytime 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 specified 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 G Certificates on the basis of a 360-day year
comprised of twelve 30-day months, that would be payable on the Class G
Certificates on each of the three successive semiannual Regular Distribution
Dates 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 G Certificates on such
day and without regard to expected future payments of principal on the Class G
Certificates. Notwithstanding the above, in the event of any Policy Provider
Election, for purposes of the definition of the Required Amount the Pool Balance
shall be deemed to be reduced by the amount (if positive) by which (a) the then
outstanding principal balance of each Series G Equipment Note in respect of
which such Policy Provider Election has been made shall exceed (b) the amount of
any Policy Drawings previously paid by the Policy Provider in respect of
principal on such Series G Equipment Note.

            "Successor Trust" means America West Airlines Pass Through Trust
2001-1G-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 G Certificates have been paid in full (or
provision has been made for such payment in accordance with the Intercreditor
Agreement and the Trust Agreement) 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 and
America West of a Termination Notice from the Liquidity Provider pursuant to
Section 6.01; 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.

            "Unapplied Provider Advance" means any Provider Advance other than
an Applied Provider Advance.

                                       6.
<PAGE>   10
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

            "Unpaid Advance" has the meaning specified 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," "Affiliate," "America West," "America West Bankruptcy
      Event," "Certificates," "Class G Cash Collateral Account," "Class G
      Certificates," "Class G Trust," "Class G Trust Agreement," "Class G
      Trustee," "Class C Certificates," "Class D Certificates," "Closing Date,"
      "Controlling Party," "Delivery Period Expiry Date," "Distribution Date,"
      "Downgraded Facility," "Equipment Notes," "Fee Letter," "Final Legal
      Distribution Date," "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," "Policy Drawings," "Policy Provider," "Policy Provider
      Election," "Pool Balance," "Purchase Agreement," "Rating Agency," "Regular
      Distribution Date," "Replacement Liquidity Facility," "Responsible
      Officer," "Scheduled Payment," "Special Payment," "Standard & Poor's,"
      "Stated Interest Rate," "Subordination Agent," "Taxes," "Threshold
      Rating," "Trust Agreement," "Trustee," and "Written Notice."

                                   ARTICLE II

                       AMOUNT AND TERMS OF THE COMMITMENT

      Section 2.01 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 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) Each "Interest Advance" shall be
made in a single Borrowing by delivery to the Liquidity Provider of a written
and completed Notice of Borrowing in substantially the form of Annex I, signed
by a Responsible Officer of the Borrower, such Interest Advance 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 G 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 and the amount available to be borrowed hereunder
by subsequent Advances by the amount of such Interest Advance (subject to
reinstatement as provided in the next sentence). Upon repayment to the Liquidity
Provider in full or in part 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

                                       7.
<PAGE>   11
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

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 G 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 shall have been 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, 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 G Cash Collateral
Account in accordance with said Section 3.6(c) and Section 3.6(f) of the
Intercreditor Agreement. Upon such downgrading, the Liquidity Provider shall
promptly deliver notice thereof to the Borrower, the Trustee and America West.

            (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, by delivery to the Liquidity Provider of a written and
completed Notice of Borrowing in substantially the form of Annex IV, 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 G Cash Collateral
Account (in accordance with Section 3.6(f) and Section 3.6(i) 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 12:00 noon (New York 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, before 4:00 p.m. (New
York time) on the date of such Borrowing or on such later Business Day specified
by the Borrower in such Notice of Borrowing, make available for the account of
its Lending Office, in U.S. dollars and in immediately available funds, the
amount of such Borrowing to be paid to the Borrower in accordance with its
payment instructions. If a Notice of Borrowing is delivered by the Borrower in
respect of any Borrowing after 12:00 noon (New York 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, before 11:00

                                       8.
<PAGE>   12
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

a.m. (New York time) on the first Business Day 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, make available to the Borrower, in accordance with
its payment instructions, in U.S. dollars and in immediately available funds,
the amount of such 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. Each Notice of Borrowing shall be
effective upon delivery of a copy thereof to the Liquidity Provider's New York
Branch at the address specified in Section 7.02.

            (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. If the Liquidity Provider
makes an Advance requested pursuant to a Notice of Borrowing before 11:00 a.m.
(New York time) on the second Business Day after the date of payment specified
in said Section 2.02(e), the Liquidity Provider shall have fully discharged its
obligations hereunder with respect to such Advance and an event of default shall
not have occurred hereunder. Following the making of any Advance pursuant to
Section 2.02(b), Section 2.02(c) or Section 2.02(d) to fund the Class G Cash
Collateral Account, the Liquidity Provider shall have no interest in or rights
to the Class G Cash Collateral Account, such Advance or any other amounts from
time to time on deposit in the Class G Cash Collateral Account; provided,
however, 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 and provided further, that the foregoing
shall not affect or impair the rights of the Liquidity Provider to provide
written instructions with respect to the investment and reinvestment of the Cash
Collateral Accounts to the extent provided in Section 2.2(b) 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 Automatic Adjustments and Termination of the Maximum
Commitment.

            (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 G Certificates or otherwise, (2) increased as a result of an increase
in the Stated Interest Rate or (3) subsequent to such 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

                                       9.
<PAGE>   13
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

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, 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; provided, however, 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, 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 G
Cash Collateral Account, invested and withdrawn from the Class G 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 G Cash Collateral Account
for the purpose of paying interest on the Class G 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 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; and provided,
further, that if, following the making of a Provider Advance, the Liquidity
Provider delivers a Termination Notice to the Borrower pursuant to Section 6.01,
such Provider Advance shall thereafter be treated as a Final Advance under this
Agreement for purposes of

                                      10.
<PAGE>   14
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

determining the Applicable Liquidity Rate for interest payable thereon and the
obligation for repayment thereof. Subject to Sections 2.07 and 2.09 hereof,
immediately upon the withdrawal of any amounts from the Class G 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 the amount of such reduction, plus interest on the
principal amount prepaid as provided in Section 3.07.

            (b) At any time when an Applied Provider Advance (or any portion
thereof) is outstanding, upon the deposit in the Class G 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 amount of 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 principal amount
of all outstanding 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 G 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 the order of priority required by the applicable provisions of
Articles II and III of 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 failure by the Liquidity
Provider to maintain such account or accounts shall not affect the obligations
of the Borrower in respect of Advances.

                                      11.
<PAGE>   15
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

      Section 2.09 Payments from Available Funds Only. All payments to be made
by the Borrower under this Agreement shall be made only from amounts received by
it that constitute Scheduled Payments or Special Payments or payments under
Section 7.1 or 9.1, as the case may be, of any Participation Agreement 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 shall 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 or
the Intercreditor Agreement. Amounts on deposit in the Class G 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 Expiry Date. No earlier than the 60' 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 G Certificates), the Borrower shall request that
the Liquidity Provider extend the Expiry Date to the earlier of (i) the date
that is 15 days after the Final Legal Distribution Date for the Class G
Certificates and (ii) the date that is the day immediately preceding the 364'
day occurring after the last day of the Consent Period (as hereinafter defined).
Whether or not the Borrower has made such request, the Liquidity Provider shall
advise the Borrower, no earlier than the 40' day (or, if earlier, the date of
the Liquidity Provider's receipt of such request, if any, from the Borrower) and
no later than the 25m day prior to the then effective Expiry Date (such period
the "Consent Period"), whether, in its sole discretion, it agrees to so extend
the Expiry Date. If the Liquidity Provider advises the Borrower on or before the
date on which the Consent Period ends that such Expiry Date shall not be so
extended, or fails to irrevocably and unconditionally advise the Borrower on or
before the date on which the Consent Period ends 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 the date on which the Consent Period
ends (but prior to the then effective Expiry Date) to request a Non-Extension
Advance in accordance with Section 2.02(b) and Section 3.6(d) of the
Intercreditor Agreement.

                                  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 costs incurred by the Liquidity Provider which are
attributable to its making or maintaining any 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

                                      12.
<PAGE>   16
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

herein called "Additional Costs"), resulting from any change after the date of
this Agreement in U.S. federal, state, or municipal, or any foreign laws or
regulations, or the adoption or making after such date of any interpretation,
regulation, directive, guideline, requirement or request whether or not having
the force of law, by any court or governmental or monetary authority charged
with the interpretation or administration thereof (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 or such obligation
(other than Taxes); or (2) imposes or modifies any reserve, special deposit,
compulsory loan or similar requirements relating to any extensions of credit or
other assets of, or any deposits with other liabilities of, the Liquidity
Provider (including any such Advances or such obligation or any deposits
referred to in the definition of LIBOR or related definitions). The Liquidity
Provider agrees to use reasonable efforts (consistent with its internal policy
and 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 3.01 that may thereafter accrue
and would not, in the reasonable judgment of the Liquidity Provider, be
otherwise disadvantageous to the Liquidity Provider.

      The Liquidity Provider shall notify the Borrower of any event occurring
after the date of this Agreement that shall 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 3.01; provided, that if the Liquidity Provider fails to give
such notice within 180 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 180 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 3.01.

      Notwithstanding the preceding two paragraphs, the Liquidity Provider and
the Subordination Agent agree that any permitted assignee or participant of the
initial Liquidity Provider that is not a bank shall not be entitled to the
benefits of the preceding two paragraphs (but without limiting the provisions of
Section 7.08 hereof).

      Section 3.02 Capital Adequacy. If (1) compliance with any judicial,
administrative or other governmental interpretation of any law or regulation or
(2) compliance by the Liquidity Provider or any corporation controlling the
Liquidity Provider with any guideline or request from any central bank or other
governmental authority (whether or not having the force of law) has the effect
of requiring an increase in the amount of capital required or expected 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 such additional amount as shall be reasonably allocable
to the Liquidity Provider's obligations to the Borrower hereunder. The Liquidity
Provider agrees to use reasonable efforts

                                      13.
<PAGE>   17
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

(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 3.02 that
may thereafter accrue and would not, in the reasonable judgment of the Liquidity
Provider, be otherwise disadvantageous to the Liquidity Provider.

      The Liquidity Provider shall notify the Borrower of any event occurring
after the date of this Agreement that shall 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 3.02; provided, that if the Liquidity Provider fails to give
such notice within 180 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 3.02 for costs incurred from and after
the date 180 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 3.02.

      Notwithstanding the preceding two paragraphs, the Liquidity Provider and
the Subordination Agent agree that any permitted assignee or participant of the
initial Liquidity Provider that is not a bank shall not be entitled to the
benefits of the preceding two paragraphs (but without limiting the provisions of
Section 7.08 hereof).

      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 Taxes, excluding Excluded Taxes (such
non-excluded taxes being referred to herein, collectively, as "Non-Excluded
Taxes"). If any Non-Excluded Taxes are required to be withheld or deducted from
any amounts payable to the Liquidity Provider under this Agreement, the Borrower
shall (i) within the time prescribed therefor by applicable law pay to the
appropriate governmental or taxing authority the full amount of any such
Non-Excluded Taxes (and any additional Non-Excluded Taxes in respect of the
payment required under clause (ii) below) and make such reports or returns in
connection therewith at the time or times and in the manner prescribed by
applicable law, and (ii) pay to the Liquidity Provider an additional amount
which (after deduction of all such Non-Excluded Taxes) shall be sufficient to
yield to the Liquidity Provider the full amount which would have been received
by it had no such withholding or deduction been made. Within 30 days after the
date of each payment hereunder, the Borrower shall furnish to the Liquidity
Provider the original or a certified copy of (or other documentary evidence of)
the payment of the Non-Excluded Taxes applicable to such payment. 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 such
additional amounts that may thereafter accrue and would not, in the reasonable
judgment of the Liquidity Provider, be otherwise materially disadvantageous (as
determined by the Liquidity Provider) to the Liquidity Provider or require the
Liquidity Provider to incur any cost or expenses for which it is not indemnified
by the Borrower. The Liquidity Provider

                                      14.
<PAGE>   18
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

shall deliver to the Borrower such certificates and documents as may be
reasonably requested by the Borrower and required by applicable law and as may
be legally delivered by the Liquidity Provider to establish that payments
hereunder are exempt from (or entitled to a reduced rate of) withholding Tax.

            (b) All payments (including, without limitation, Advances) made by
the Liquidity Provider under this Agreement shall be made free and clear of, and
without reduction for or on account of, any Taxes. If any Taxes are required to
be withheld or deducted from any amounts payable to the Borrower under this
Agreement, the Liquidity Provider shall (i) within the time prescribed therefor
by applicable law pay to the appropriate governmental or taxing authority the
full amount of any such Taxes (and any additional Taxes in respect of the
additional amounts payable under clause (ii) hereof) and make such reports or
returns in connection therewith at the time or times and in the manner
prescribed by applicable law, and (ii) pay to the Borrower an additional amount
which (after deduction of all such Taxes) shall be sufficient to yield to the
Borrower the full amount which would have been received by it had no such
withholding or deduction been made. Within 30 days after the date of each
payment hereunder, the Liquidity Provider shall furnish to the Borrower the
original or a certified copy of (or other documentary evidence of) the payment
of the Taxes applicable to such payment.

            (c) If any exemption from, or reduction in the rate of, any Taxes is
reasonably available to the Borrower to establish that payments under this
Agreement are exempt from (or entitled to a reduced rate of) tax, the Borrower
shall deliver to the Liquidity Provider such form or forms and such other
evidence of the eligibility of the Borrower for such exemption or reduction as
the Liquidity Provider may reasonably identify to the Borrower as being required
as a condition to exemption from, or reduction in the rate of, any Taxes.

      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 The Chase Manhattan Bank, New York, ABA No.
021000021, Account Name: Westdeutsche Landesbank Girozentrale, New York Branch,
Account No. 9201-06-0663, ref. GSF/Transportation, America West Airlines
2001-1G, Attention: Phil Green.

      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 shall be made on the
basis of a year of 360 days, in each 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

                                      15.
<PAGE>   19
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

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 shall 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 G Cash Collateral Account
to pay interest on the Class G 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 G 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 applicable 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 (as defined below)
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 shall 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. Nothing contained in this Section 3.07 shall require the Borrower to
pay any amount under this Section 3.07 other than to the extent the Borrower
shall have funds available therefor.

            (b) Each Advance shall be either a Base Rate Advance or a LIBOR
Advance as provided in this Section or Section 3.10. Each such Advance shall 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; provided, however, that the Borrower (at the direction of the
Controlling Party, so long as the Liquidity Provider is not the Controlling
Party) may (x) convert the Final Advance into a Base Rate Advance on the last
day of an Interest Period for such Advance by giving the Liquidity Provider no
less than four Business Days' prior written notice of such election or (y) elect
to maintain the Final Advance as a Base Rate Advance by not requesting a
conversion of the Final Advance to a LIBOR Advance under Clause (5) of the
applicable Notice of Borrowing (or, if such Final Advance is deemed to have been
made, without delivery of a Notice of Borrowing pursuant to Section 2.06, by
requesting, prior to 11:00 A.M. (New York time) on the first Business Day
following the Borrower's receipt of the applicable Termination Notice, that such
Final Advance not be converted from a Base Rate Advance to a LIBOR Advance).

                                      16.
<PAGE>   20
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

            (c) Each LIBOR Advance shall bear interest during each Interest
Period at a rate per annum equal to LIBOR 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 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 2.50% per annum.

            (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 Borrower. Subject to Section 5.02, from time
to time and subject to the successor Borrower'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 (a "Notice of Replacement Subordination Agent") delivered
to the Liquidity Provider by the then Borrower, the successor Borrower
designated therein shall be substituted for as the Borrower 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, cost, or expense incurred 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.

                                      17.
<PAGE>   21
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

      Section 3.10 Illegality. Notwithstanding any other provision in this
Agreement, if any change in any applicable law, rule or regulation, or any
change in the interpretation or administration thereof by any governmental
authority, central bank or comparable agency charged with the interpretation or
administration thereof, or compliance by the Liquidity Provider (or its Lending
Office) with any request or directive (whether or not having the force of law)
of any such authority, central bank or comparable agency shall make it unlawful
or impossible for the Liquidity Provider (or its Lending Office) to maintain or
fund its LIBOR Advances, 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 (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.

                                   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), 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 (other than the Liquidity Provider);

                  (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 G Certificates;

                  (v) An executed copy of each opinion, document, instrument and
      certificate delivered on or before the Closing Date pursuant to the Class
      G Trust Agreement, the Intercreditor Agreement, the Note Purchase
      Agreement and the other Operative Agreements entered into on or prior to
      the date hereof (together with, in the case of each such opinion, other
      than the opinion of counsel for the Underwriters, either addressed to the
      Liquidity Provider or accompanied by a letter from the counsel rendering
      such opinion to the

                                      18.
<PAGE>   22
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

      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
      may be reasonably necessary or, to the extent reasonably requested by the
      Liquidity Provider, reasonably advisable, in order to establish, perfect,
      protect and preserve the right, title and interest, remedies, powers,
      privileges, liens and security interests of, or for the benefit of, the
      Trustee and the Liquidity Provider created by the Operative Agreements
      executed and delivered on or before 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 lOQ
      and l OK), 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 to Section 4.08 of the Indentures (related
      to Owned Aircraft) to the parties thereto; and

                  (viii)Such other documents, instruments, opinions and
      approvals as the Liquidity Provider shall have reasonably requested.

            (b) The following statements shall be true on and as of the
Effective Date:

                  (i) The representations and warranties in the Note Purchase
      Agreement and each of the Participation Agreements entered into on or
      prior to the date hereof are true and correct on and as of the Effective
      Date as though made on-and as of the Effective Date;

                  (ii) 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; and

                  (iii) There has been no material adverse change in the
      financial condition or results of operations of America West and its
      subsidiaries taken as a whole since December 31, 2000.

            (c) The Liquidity Provider shall have received payment in full of
all fees and other sums required to be paid to or for the 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 Facility shall have been
satisfied or waived, and all conditions precedent to the

                                      19.
<PAGE>   23
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

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 shall, unless the Liquidity Provider
shall otherwise consent in writing:

            (a) Performance of 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.

            (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 any Operative Agreement entered into after the date
hereof.

      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 shall not appoint or permit or suffer
to be appointed any successor Borrower without the written consent of the
Liquidity Provider, which consent shall not be unreasonably withheld or delayed.

                                      20.
<PAGE>   24
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

                                   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)
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, 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, the Borrower, and then
such waiver or consent shall be effective only in the specific instance and for
the specific purpose for which given.

      Section 7.02 Notices, Etc. Except as otherwise expressly provided herein,
all notices and other communications provided for hereunder shall be in writing
(including sent by telecopier):

      Borrower:         Wilmington Trust Company
                        Rodney Square North
                        1100 North Market Street
                        Wilmington, DE 19890-0001
                        Attention: Corporate Trust Administration
                        Telephone: 302-651-1000
                        Telecopy: 302-651-8882

                                      21.
<PAGE>   25
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

      Liquidity
      Provider:         Westdeutsche Landesbank Girozentrale
                        New York Branch
                        1211 Avenue of the Americas
                        New York, New York 10036
                        Business/Credit Contact
                        Attention:  Transportation Finance
                        Global Structured Finance/Americas

                        Telephone: 212-852-6115
                        Telecopy: 212-869-7634

                        Operations Contact
                        Attention: Philip Green
                                   Loan Administration

                        Telephone: 212-852-6113
                        Telecopy: 212-302-7946

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 (i) if given by telecopier, when transmitted
to the telecopier number specified above with receipt confirmed, (ii) if given
by mail, when deposited in the mails addressed as specified above, and (iii) if
given by other means, when delivered at the address specified above, except that
Written Notices to the Liquidity Provider pursuant to the provisions of Articles
II and III shall not be effective until received by the Liquidity Provider,
subject to the last sentence of Section 2.02(e). 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.

      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.

                                      22.

<PAGE>   26
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

      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 any Participation
Agreement and Section 6(c) of the Note Purchase Agreement. In addition, the
Borrower agrees to indemnify, protect, defend and hold harmless the Liquidity
Provider from, against and in respect of, and shall pay on demand, all Expenses
of any kind or nature whatsoever (other than any Expenses of the nature
described in Section 3.01, 3.02 or 7.07 hereof or in the Fee Letter (regardless
of whether indemnified against pursuant to said Sections or in such Fee Letter))
that may be imposed, incurred by or asserted against any Liquidity Indemnitee,
in any way relating to, resulting from, or arising out of or in connection with
any action, suit or proceeding by any third party against such Liquidity
Indemnitee and relating to this Agreement, the Intercreditor Agreement, the Fee
Letter or any Participation Agreement; provided, however, that the Borrower
shall not be required to indemnify, protect, defend and hold harmless any
Liquidity Indemnitee in respect of any Expense of such Liquidity Indemnitee to
the extent such Expense is (i) attributable to the gross negligence or willful
misconduct of such Liquidity Indemnitee or any other Liquidity Indemnitee, (ii)
ordinary and usual operating overhead expense or (iii) attributable to the
failure by such Liquidity Indemnitee or any other Liquidity Indemnitee to
perform or observe any agreement, covenant or condition on its part to be
performed or observed in this Agreement, the Intercreditor Agreement, the Fee
Letter or any other Operative Agreement to which it is a party. The indemnities
contained in Section 6(c) of the Note Purchase Agreement and Section 7.1 or 9.1,
as the case may be, of any Participation Agreement and the provisions of
Sections 3.01, 302, 3.03, 3.09, 7.05 and 7.07 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, directors, employees 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; (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; or (iii) the making of Advances by the Liquidity Provider against
delivery of a Notice of Borrowing and other documents which do not comply with
the terms hereof; 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 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

                                      23.
<PAGE>   27
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

event the extent of the Liquidity Provider's potential liability to the Borrower
shall be limited as set forth in the 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 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, including, without limitation, the reasonable
fees and expenses of outside counsel for the Liquidity Provider and (B) on
demand, all reasonable costs and expenses of the Liquidity Provider (including
reasonable counsel fees and expenses) 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 Agreement
or such other documents which may be delivered in connection herewith or
therewith (whether or not the same shall become effective) 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 G Cash
Collateral Account. 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, 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 the Borrower
(except as contemplated by Section 3.08) 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 and under the other Operative Agreements to such Persons (other than
America West or any of its Affiliates) 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, shall 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. Accordingly,
references in this Agreement and the other Operative Agreements to
determinations, reserve and capital adequacy requirements, increased costs,
reduced receipts and the like as they pertain to the Liquidity Provider shall be
deemed also to include those of each of its participants that are banks
(subject, in each case, to the maximum amount that would have been incurred by
or attributable to the Liquidity Provider

                                      24.
<PAGE>   28
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

directly if the Liquidity Provider, rather than the participant, had held the
interest participated other than a result of a change in law following the date
of any participation).

            (b) If, pursuant to Section 7.08(a) above, the Liquidity Provider
sells any participation in this Agreement to any bank or other entity (each, a
"Participating Institution"), then, concurrently with the effectiveness of such
participation, the Participating Institution 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 shall be
required to be withheld by the Borrower or the Liquidity Provider with respect
to any payments to be made to such Participating Institution 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 state
thereof or (y) if it is not so incorporated, two copies of a properly completed
United States Internal Revenue Service Form W-8ECI or Form W-8BEN, as
appropriate, or other applicable form, certificate or document prescribed by the
Internal Revenue Service certifying, in each case, such Participating
Institution'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 W-8ECI or Form
W-8BEN, 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 W-8BEN or Form W-8ECI that such Participating Institution 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) from
the Participating Institution indicating that payments hereunder are not subject
to United States federal withholding tax, the Borrower shall withhold taxes as
required by law from such payments at the applicable statutory rate without any
obligation to make additional payments under Section 3.03.

            (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.

                                      25.
<PAGE>   29
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

      Section 7.10 GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK (WITHOUT REGARD
TO THE PRINCIPLES OF CONFLICTS OF LAWS THEREOF (OTHER THAN SECTION 5-1401 OF THE
NEW YORK GENERAL OBLIGATIONS LAW)) AND THE OBLIGATIONS, RIGHTS AND REMEDIES OF
THE PARTIES UNDER THIS AGREEMENT SHALL BE DETERMINED IN ACCORDANCE WITH SUCH
LAWS.

      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 non-exclusive 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 of mail), postage
      prepaid, to each party hereto at its address set forth in Section 7.02, 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

                                      26.
<PAGE>   30
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

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 counterpart, 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 and the other Operative Agreements
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.

      Section 7.15 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.

      Section 7.16 Transfer. The Liquidity Provider hereby acknowledges and
consents to the Transfer contemplated by the Assignment and Assumption
Agreement.

                                      27.
<PAGE>   31
      IN WITNESS WHEREOF, the parties hereto 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 and Trustee, as
                                       Borrower

                                       By:   /s/ Anita Dallago
                                           -------------------------------------
                                             Name: Anita Dallago
                                             Title: Financial Services Officer

                                       WESTDEUTSCHE LANDESBANK GIROZENTRALE, NEW
                                       YORK BRANCH
                                       as Liquidity Provider

                                       By:   /s/ Brigitte Thieme
                                           -------------------------------------
                                             Name: Brigitte Thieme
                                             Title: Managing Director

                                       By:   /s/ Alfred Heynen
                                           -------------------------------------
                                             Name: Alfred Heynen
                                             Title: Associate Director

                                      I-1
<PAGE>   32
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

                                                                      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 Westdeutsche Landesbank Girozentrale (the
"Liquidity Provider"), with reference to the Revolving Credit Agreement
(2001-1G), dated as of May-, 2001, 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 G
      Certificates which was payable on __________ (the "Distribution Date") in
      accordance with the terms and provisions of the Class G Trust Agreement
      and the Class G Certificates, which Advance is requested to be made on
      __________. The Interest Advance should be transferred to account
      __________.

            (3) The amount of the Interest Advance requested hereby (i) is
      $__________, to be applied in respect of the payment of interest which was
      due and payable on the Class G Certificates on such Distribution Date,
      (ii) does not include any amount with respect to the payment of principal
      of, or premium on, the Class G Certificate, the Class C Certificates or
      the Class D Certificates, or interest on the Class C Certificates or the
      Class D Certificates, (iii) was computed in accordance with the provisions
      of the Class G Certificates, the Class G 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 G 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 shall 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

                                      I-2
<PAGE>   33
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

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 requested to be made hereby as set forth in clause (i) of paragraph (3)
of this Notice of Borrowing 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-3
<PAGE>   34
                 SCHEDULE I TO INTEREST ADVANCE NOTICE OF BORROWING

     [Insert Copy of Computations in accordance with Interest Advance Notice of
                                     Borrowing]

                                      I-4
<PAGE>   35
                                                                     Annex II to
                                                      Revolving Credit Agreement

                     NON-EXTENSION ADVANCE NOTICE OF BORROWING

      The undersigned, a duly authorized signatory of the undersigned borrower
(the "Borrower"), hereby certifies to Westdeutsche Landesbank Girozentrale (the
"Liquidity Provider"), with reference to the Revolving Credit Agreement
(2001-1G), dated as of May-, 2001, 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 G Cash Collateral Account in accordance with
      Section 3.6(d) of the Intercreditor Agreement, which Advance is requested
      to be made on __________, ____. The Non-Extension Advance should be
      transferred to __________.

            (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 G 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 G Certificates, the Class C
      Certificates or the Class D Certificates, or interest on the Class C
      Certificates or the Class D Certificates, (iii) was computed in accordance
      with the provisions of the Class G Certificates, the Class G Trust
      Agreement and the Intercreditor Agreement (a copy of which computation is
      attached hereto as Schedule 1), 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 G
      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>   36
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

      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>   37
                       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>   38
                                                                    Annex III to
                                                      Revolving Credit Agreement

                      DOWNGRADE ADVANCE NOTICE OF BORROWING

      The undersigned, a duly authorized signatory of the undersigned borrower
(the "Borrower"), hereby certifies to Westdeutsche Landesbank Girozentrale (the
"Liquidity Provider"), with reference to the Revolving Credit Agreement
(2001-1G) dated as of May-, 2001, 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 G 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 __________. The Downgrade Advance should be
      transferred to __________.

            (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 G 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
      principal of, or premium on, the Class G Certificates, the Class C
      Certificates, or the Class D Certificates, or interest on the Class C
      Certificates or the Class D Certificates, (iii) was computed in accordance
      with the provisions of the Class G Certificates, the Class G Trust
      Agreement and the Intercreditor Agreement (a copy of which computation is
      attached hereto as Schedule 1), 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 shall deposit such amount in the Class
      G 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 Provider of the Downgrade

                                     III-1
<PAGE>   39
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

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:

                                     III-2
<PAGE>   40
                SCHEDULE I TO DOWNGRADE ADVANCE NOTICE OF BORROWING

                  [Insert Copy of Computations in accordance with
                       Downgrade Advance Notice of Borrowing]

                                     III-3
<PAGE>   41
                                                                     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 Westdeutsche Landesbank Girozentrale (the
"Liquidity Provider"), with reference to the Revolving Credit Agreement
(2001-1G), dated as of May __, 2001, 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 G 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 G 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 G Certificates, the Class C
      Certificates or the Class D Certificates, or interest on the Class C
      Certificates or the Class D Certificates, (iii) was computed in accordance
      with the provisions of the Class G Certificates, the Class G 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 shall deposit such amount in the Class
      G 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.

                                      IV-1
<PAGE>   42
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

            (5) The Borrower hereby requests that the Advance requested hereby
      be a Base Rate Advance [and that such Base Rate Advance be converted into
      a LIBOR Advance on the third Business Day following your receipt of this
      notice.](1)

            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.

            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:

--------

(1)    Bracketed language may be included at Borrower's option.

                                      IV-2
<PAGE>   43
                  SCHEDULE I TO FINAL ADVANCE NOTICE OF BORROWING

                  [Insert Copy of Computations in accordance with
                         Final Advance Notice of Borrowing]

                                      IV-3
<PAGE>   44
                                                                      Annex V to
                                                      Revolving Credit Agreement

                              NOTICE OF TERMINATION

                                     [Date]

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

Attention: Corporate Trust Administration

Re:   Revolving Credit Agreement (2001-1G), dated as of May-, 2001, between
      Wilmington Trust Company, as Subordination Agent, as agent and trustee for
      the America West Airlines 2001-1G Pass Through Trust, as Borrower, and
      Westdeutsche Landesbank Girozentrale, New York Branch (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.

      THIS NOTICE IS THE "NOTICE OF TERMINATION" PROVIDED FOR UNDER THE
LIQUIDITY AGREEMENT. OUR OBLIGATIONS TO MAKE ADVANCES UNDER THE LIQUIDITY
AGREEMENT SHALL TERMINATE ON THE FIFTH BUSINESS DAY AFTER THE DATE ON WHICH YOU
RECEIVE THIS NOTICE.

                                      V-1
<PAGE>   45
                                          [REVOLVING CREDIT AGREEMENT (2001-1G)]

                                     Very truly yours,

                                     WESTDEUTSCHE LANDESBANK GIROZENTRALE, NEW
                                     YORK BRANCH, as Liquidity Provider

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

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

cc:   Wilmington Trust Company,
      as Class G Trustee

                                      V-2
<PAGE>   46
                                                                     Annex VI to
                                                      Revolving Credit Agreement

                     NOTICE OF REPLACEMENT SUBORDINATION AGENT

                                     [Date]

Attention:

Re:   Revolving Credit Agreement (2001-1G), dated as of May-, 2001, between
      Wilmington Trust Company, as Subordination Agent, as agent and trustee for
      the America West Airlines 2001-1G Pass Through Trust, as Borrower, and
      Westdeutsche Landesbank Girozentrale (the "Liquidity Agreement")

Ladies and Gentlemen:

      For value received, the undersigned hereby irrevocably transfers to:

                                       _________________________________________
                                       [Name of Transferee]

                                       _________________________________________
                                       [Address of Transferee]

all rights and obligations of the undersigned as Borrower and Subordination
Agent under the Liquidity Agreement referred to above. The transferee has
succeeded the undersigned as Borrower and 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 and
Subordination Agent under the Liquidity Agreement are transferred to the
transferee and the transferee shall hereafter have the sole rights and
obligations as Borrower and Subordination Agent thereunder. The undersigned
shall pay any costs and expenses of such transfer, including, but not limited
to, transfer taxes or governmental charges.

      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-1

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