<PAGE>   1
                                   EXHIBIT 4.8

                                                                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-O

             Initial Pass Through Certificates, Series 2001-1D-O
             Exchange Pass Through Certificates, Series 2001-1D-O
<PAGE>   2
Reconciliation and tie between America West Airlines Pass Through Trust
Agreement, Series 2001-1D-O 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.

          Trust Indenture Act                      Pass Through Trust
             of 1939 Section                        Agreement Section
          ------------------                       -----------------
            310(a)(1)                                   7.08
                (a)(2)                                  7.08
            312(a)                                      3.05; 8.01; 8.02
            313(a)                                      7.06; 8.03
            314(a)                                      8.04(a),(c) & (d)
            (a)(4)                                      8.04(e)
            (c)(1)                                      1.02
            (c)(2)                                      1.02
            (d)(1)                                      7.13; 11.01
            (d)(2)                                      7.13; 11.01
            (d)(3)                                      2.01
            (e)                                         1.02
            315(b)                                      7.02
            316(a)(last sentence)                       1.04(c)
                (a)(1)(A)                               6.04
                (a)(1)(B)                               6.05
                (b)                                     6.06
                (c)                                     1.04(e)
            317(a)(1)                                   6.03
                (b)                                     7.13
            318(a)                                      12.06
<PAGE>   3
                                TABLE OF CONTENTS
<TABLE>
<CAPTION>
SECTION                                                                                                            PAGE
<S>                                                                                                               <C>
ARTICLE I  DEFINITIONS ..........................................................................................    2
         Section 1.01.     Definitions...........................................................................    2
         Section 1.02.     Compliance Certificates and Opinions..................................................   14
         Section 1.03.     Form of Documents Delivered to Trustee................................................   15
         Section 1.04.     Directions of Certificateholders......................................................   15

ARTICLE II  ORIGINAL ISSUANCE OF CERTIFICATES; ACQUISITION OF EQUIPMENT NOTES....................................   16
         Section 2.01.     Issuance of Certificates; Acquisition of Equipment Notes..............................   16
         Section 2.02.     Withdrawal of Deposits................................................................   17
         Section 2.03.     Acceptance by Trustee.................................................................   18
         Section 2.04.     Limitation of Powers..................................................................   18

ARTICLE III  THE CERTIFICATES....................................................................................   18
         Section 3.01.     Title, Form, Denomination and Execution of Certificates...............................   18
         Section 3.02.     Restrictive Legends...................................................................   20
         Section 3.03.     Authentication of Certificates........................................................   22
         Section 3.04.     Transfer and Exchange.................................................................   22
         Section 3.05.     Book-Entry Provisions for Restricted Global Certificates and Regulation S
                           Global Certificates...................................................................   23
         Section 3.06.     Special Transfer Provisions...........................................................   24
         Section 3.07.     Mutilated, Destroyed, Lost or Stolen Certificates.....................................   27
         Section 3.08.     Persons Deemed Owners.................................................................   28
         Section 3.09.     Cancellation..........................................................................   28
         Section 3.10.     Temporary Certificates................................................................   28
         Section 3.11.     Limitation of Liability for Payments..................................................   28
         Section 3.12      ERISA Restrictive Legend..............................................................   29

ARTICLE IV  DISTRIBUTIONS; STATEMENTS TO CERTIFICATEHOLDERS......................................................   29
         Section 4.01.     Certificate Account and Special Payments Account......................................   29
         Section 4.02.     Distributions from Certificate Account and Special Payments Account...................   30
         Section 4.03.     Statements to Certificateholders......................................................   31
         Section 4.04.     Investment of Special Payment Moneys..................................................   32

ARTICLE V  THE COMPANY ..........................................................................................   33
         Section 5.01.     Maintenance of Corporate Existence....................................................   33
         Section 5.02.     Consolidation, Merger, etc............................................................   33

ARTICLE VI  DEFAULT .............................................................................................   34
         Section 6.01.     Events of Default.....................................................................   34
         Section 6.02.     Incidents of Sale of Equipment Notes..................................................   35
         Section 6.03.     Judicial Proceedings Instituted by Trustee; Trustee May Bring Suit....................   36
</TABLE>
<PAGE>   4
<TABLE>
<CAPTION>
SECTION                                                                                                            PAGE
<S>                                                                                                               <C>
         Section 6.04      Control by Certificateholders.........................................................   36
         Section 6.05.     Waiver of Past Defaults...............................................................   36
         Section 6.06.     Right of Certificateholders to Receive Payments Not to Be Impaired....................   37
         Section 6.07.     Certificateholders May Not Bring Suit Except Under Certain Conditions.................   37
         Section 6.08.     Remedies Cumulative...................................................................   38

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

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

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

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

                                       ii
<PAGE>   5
<TABLE>
<CAPTION>
SECTION                                                                                                            PAGE
<S>                                                                                                               <C>
ARTICLE XI  TERMINATION OF TRUST.................................................................................   53
         Section 11.01.    Termination of the Trust..............................................................   53

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


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

                                      iii
<PAGE>   6
                       PASS THROUGH TRUST AGREEMENT


            This PASS THROUGH TRUST AGREEMENT, dated as of 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-O and the issuance of
America West Airlines Pass Through Trust, Series 2001-1D-O Pass Through
Certificates representing fractional undivided interests in the Trust.

                                   WITNESSETH:

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

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

            WHEREAS, in the case of each Leased Aircraft, each Owner Trustee,
acting on behalf of the corresponding Owner Participant, will issue pursuant to
an Indenture, on a non-recourse basis, three series of Equipment Notes in order
to finance a portion of its purchase price of such Leased Aircraft;

            WHEREAS, in the case of each Owned Aircraft, the Company will issue
pursuant to an Indenture, on a recourse basis, three series of Equipment Notes
to finance a portion of the purchase price of such Owned Aircraft;

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

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

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

            WHEREAS, the Escrow Agent on behalf of the Certificateholders has
contemporaneously herewith entered into a Deposit Agreement with the Depositary
under which
<PAGE>   7
                                      -2-


the Deposits referred to therein will be made and from which it will withdraw
funds to allow the Trustee to purchase Equipment Notes from time to time prior
to the Delivery Period Termination Date;

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

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

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

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

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


                                    ARTICLE I

                                   DEFINITIONS

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

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

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

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

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

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

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

            Agent Members:  Has the meaning specified in Section 3.05.

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

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

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

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

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

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

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

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


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

            AVSA:  Means AVSA S.A.R.L., an affiliate of Airbus 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 and any such Certificates issued in exchange
      therefor or replacement thereof pursuant to this Agreement.

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

            Certificate Purchase Agreement: Means the Purchase Agreement dated
      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.

            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.

            Clearstream:  Means Clearstream Banking, societe anonyme,
      organized under Luxembourg law (formerly known as Cedelbank) or any
      successor thereto.
<PAGE>   10
                                      -5-



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

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

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

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

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

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

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

            Delivery Period Termination Date: Means the earlier of (a) August
      30, 2002, or, if the Equipment Notes relating to all of the Aircraft (or
      Substitute Aircraft in lieu thereof) have not been purchased by the
      Trustee and the Other Trustees on or prior to such date due to any reason
      beyond the control of the Company and not occasioned by the Company's
      fault or negligence, November 30, 2002 and (b) the date on which Equipment
      Notes issued with respect to all of the Aircraft (or Substitute Aircraft
      in lieu thereof) have been purchased by the Trustee and the Other Trustees
      in accordance with the Note Purchase Agreement.

            Deposits:  Has the meaning specified in the Deposit Agreement.

            Deposit Agreement: Means the Deposit Agreement dated as of 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.
<PAGE>   11
                                      -6-



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

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

            ERISA:  Means the Employee Retirement Income Security Act of
      1974, as amended from time to time, or any successor federal statute.

            ERISA Legend:  Has the meaning specified in Section 3.12.

            Escrow Agent:  Means, initially, Wilmington Trust Company.

            Escrow Agreement: Means the Escrow and Paying Agent Agreement dated
      as of May 17, 2001 relating to the Certificates, among the Escrow Agent,
      the Escrow Paying Agent, the Trustee and the Initial Purchasers, as the
      same may be amended, supplemented or otherwise modified from time to time
      in accordance with its terms.

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

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

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

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

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

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

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

            Final Legal Distribution Date:  Means October 2, 2005.

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

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

            Final Withdrawal Notice:  Has the meaning specified in Section
      2.02.
<PAGE>   12
                                      -7-



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

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

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

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

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

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

            Initial Certificates:  Means the certificates issued and
      authenticated hereunder substantially in the form of Exhibit A hereto
      other than the Exchange Certificates.

            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 Trustee, the Other Trustees, the Liquidity
      Provider, the liquidity provider relating to the Certificates issued under
      (and as defined in) the Other Pass Through Trust Agreement, 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.

            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.

            Investors:  Means the Initial Purchasers together with all
      subsequent beneficial owners of the Certificates.
<PAGE>   13
                                      -8-

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

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

            Offering Circular: Means the Offering Memorandum dated May 10, 2001
      relating to the offering of the Certificates and the certificates issued
      under the Other Pass Through Trust Agreements.

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

            Opinion of Counsel: Means a written opinion of legal counsel who (a)
      in the case of counsel for the Company may be (i) the General Counsel of
      the Company, (ii) Cooley Godward LLP, (iii) Vedder, Price, Kaufman &
      Kammholz 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
<PAGE>   14
                                      -9-


      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 Agreement: Means the other America West
      Airlines 2001-1 Pass Through Trust Agreements relating to America West
      Airlines Pass Through Trust, Series 2001-1G-O and the America West
      Airlines Pass Through Trust, Series 2001-1C-O, dated the date hereof.

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

            Other Trusts:  Means the America West Airlines Pass Through
      Trust, Series 2001-1G-O and the America West Airlines Pass Through
      Trust, Series 2001-1C-O, created on the date hereof.

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

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

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

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

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

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

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

            Participation Agreement: Means each Participation Agreement to be
      entered into by the Trustee pursuant to the Note Purchase Agreement, as
      the same may be amended, supplemented or otherwise modified in accordance
      with its terms.
<PAGE>   15
                                      -10-

            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.

            Pool Balance: Means, as of any date, (i) the original aggregate face
      amount of the Certificates less (ii) the aggregate amount of all payments
      made in respect of such Certificates other than payments made in respect
      of interest, 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.
      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
<PAGE>   16
                                      -11-

            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 Trustee, the Other Trustees and the Company, as amended, supplemented
      or otherwise modified from time to time in accordance with its terms.

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

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

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

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

            Related Pass Through Trust Agreement: Means the Pass Through Trust
      Agreement relating to the America West Airlines Pass Through Trust, Series
      2001-1D-S, dated the date hereof, between the Company and the institution
      acting as trustee thereunder, which agreement becomes effective upon the
      execution and delivery of the Assignment and Assumption Agreement pursuant
      to Section 11.01.

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



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

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

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

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

            Restricted Legend: Has the meaning specified in Section 3.02.

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

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

            Scheduled Payment: With respect to any Equipment Note, means 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.
<PAGE>   18
                                      -13-


            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).

            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: Has the meaning specified in Section 11.01.

            Triggering Event: Has the meaning assigned to such term in the
      Intercreditor Agreement.

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

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

            Trust Property: Means (i) the Equipment Notes held as the property
      of the Trust and, subject to the Intercreditor Agreement, all monies at
      any time paid thereon and all monies due and to become due thereunder,
      (ii) funds from time to time deposited in the Certificate Account and the
      Special Payments Account and, subject to the Intercreditor Agreement, any
      proceeds from the sale by the Trustee pursuant to Article VI hereof of any
      Equipment Note and (iii) all rights of the Trust and the Trustee, on
      behalf of the Trust, under the Intercreditor Agreement, the Escrow
      Agreement and the Note Purchase
<PAGE>   19
                                      -14-


      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
      herein, will not constitute Trust Property.

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

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

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

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

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

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

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

            (3) a statement that, in the opinion of each such individual, he has
      made such examination or investigation as is necessary to enable him to
      express an informed opinion as to whether or not such covenant or
      condition has been complied with; and
<PAGE>   20
                                      -15-



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

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

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

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

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

            (c) In determining whether the Certificateholders of the requisite
Fractional Undivided Interests of Certificates Outstanding have given any
Direction under this Agreement, Certificates owned by the Company or any
Affiliate thereof shall be disregarded and deemed not to be Outstanding for
purposes of any such determination. In determining whether the Trustee shall be
protected in relying upon any such Direction, only Certificates which the
Trustee knows to be so owned shall be so disregarded. Notwithstanding the
foregoing, (i) if any such Person owns 100% of the Certificates Outstanding,
such Certificates shall not be so disregarded, and (ii) if any amount of
Certificates so owned by any such Person have been pledged in good faith,
<PAGE>   21
                                      -16-


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

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

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

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

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


                                   ARTICLE II

                       ORIGINAL ISSUANCE OF CERTIFICATES;
                         ACQUISITION OF EQUIPMENT NOTES

            Section 2.01. Issuance of Certificates; Acquisition of Equipment
Notes. (a) The Trustee is hereby directed (i) to execute and deliver the
Intercreditor Agreement, the Registration Rights Agreement, the Escrow Agreement
and the Note Purchase Agreement on or prior to the Issuance Date, each in the
form delivered to the Trustee by the Company and (ii) subject to the respective
terms thereof, to perform its obligations thereunder. Upon request of the
Company and the satisfaction or waiver of the closing conditions specified in
the Certificate Purchase Agreement, the Trustee shall execute, deliver,
authenticate, issue and sell Certificates in authorized denominations equaling
in the aggregate the amount set forth, with respect to the Trust, in Schedule II
to the Certificate Purchase Agreement evidencing the entire ownership interest
in the Trust, which amount equals the maximum aggregate principal amount of
Equipment Notes which may be purchased by the Trustee pursuant to the Note
Purchase Agreement. Except as provided in Sections 3.04, 3.05, 3.06, 3.07 and
3.10 hereof, the Trustee
<PAGE>   22
                                      -17-


shall not execute, authenticate or deliver Certificates in excess of the
aggregate amount specified in this paragraph.

            (b) On or after the Issuance Date, the Company may deliver from time
to time to the Trustee a Delivery Notice relating to one or more Equipment
Notes. After receipt of a Delivery Notice and in any case no later than one
Business Day prior to a Delivery Date as to which such Delivery Notice relates
(the "Applicable Delivery Date") (or, if the Issuance Date is an Applicable
Delivery Date, on the Issuance Date), the Trustee shall (as and when specified
in the Delivery Notice) instruct the Escrow Agent to provide a Notice of
Purchase Withdrawal to the Depositary requesting (A) the withdrawal of one or
more Deposits on the Applicable Delivery Date in accordance with and to the
extent permitted by the terms of the Escrow Agreement and the Deposit Agreement
and (B) the payment of all, or a portion, of such Deposit or Deposits in an
amount equal in the aggregate to the purchase price of such Equipment Notes to
or on behalf of the Owner Trustee or the Company, as the case may be, issuing
such Equipment Notes, all as shall be described in the Delivery Notice; provided
that, if the Issuance Date is an Applicable Delivery Date, such purchase price
shall be paid from a portion of the proceeds of the sale of the Certificates.
The Trustee shall (as and when specified in such Delivery Notice), subject to
the conditions set forth in Section 2 of the Note Purchase Agreement, enter into
and perform its obligations under the Participation Agreement specified in such
Delivery Notice (the "Applicable Participation Agreement") and cause such
certificates, documents and legal opinions relating to the Trustee to be duly
delivered as required by the Applicable Participation Agreement. If at any time
prior to the Applicable Delivery Date, the Trustee receives a notice of
postponement pursuant to Section 2(e) or 2(f) of the Note Purchase Agreement,
then the Trustee shall give the Depositary (with a copy to the Escrow Agent) a
notice of cancellation of such Notice of Purchase Withdrawal relating to such
Deposit or Deposits on such Applicable Delivery Date. Upon satisfaction of the
conditions specified in the Note Purchase Agreement and the Applicable
Participation Agreement, the Trustee shall purchase the applicable Equipment
Notes with the proceeds of the withdrawals of one or more Deposits made on the
Applicable Delivery Date in accordance with the terms of the Deposit Agreement
and the Escrow Agreement (or, if the Issuance Date is the Applicable Delivery
Date with respect to such Applicable Participation Agreement, from a portion of
the proceeds of the sale of the Certificates). The purchase price of such
Equipment Notes shall equal the principal amount of such Equipment Notes.
Amounts withdrawn from such Deposit or Deposits in excess of the purchase price
of the Equipment Notes or to the extent not applied on the Applicable Delivery
Date to the purchase price of the Equipment Notes, shall be re-deposited by the
Trustee with the Depositary on the Applicable Delivery Date in accordance with
the terms of the Deposit Agreement.

            Section 2.02. Withdrawal of Deposits. If any Deposits remain
outstanding on the Business Day next succeeding the Cut-Off Date, (i) (A) the
Trustee shall give the Escrow Agent notice that the Trustee's obligation to
purchase Equipment Notes under the Note Purchase Agreement has terminated and
instruct the Escrow Agent to provide a notice of Final Withdrawal to the
Depositary substantially in the form of Exhibit B to the Deposit Agreement (the
"Final Withdrawal Notice") and (B) the Trustee will make a demand upon the
Company under the Note Purchase Agreement for an amount equal to the Special
Redemption Premium, if applicable, such payment to be made on the Final
Withdrawal Date.
<PAGE>   23
                                      -18-



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

            Section 2.04. Limitation of Powers. The Trust is constituted solely
for the purpose of making the investment in the Equipment Notes, and, except as
set forth herein, the Trustee shall not be authorized or empowered to acquire
any other investments or engage in any other activities 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 shall be known as the "Initial Pass
Through Certificates, Series 2001-1D-O" and the Exchange Certificates shall be
known as the "Exchange Pass Through Certificates, Series 2001-1D-O", in each
case, of the Trust. Each Certificate will represent a fractional undivided
interest in the Trust and shall be substantially in the form set forth as
Exhibit A hereto, with such appropriate insertions, omissions, substitutions and
other variations as are required or permitted by this Agreement and may have
such letters, numbers or other marks of identification and such legends or
endorsements placed thereon as may be required to comply with the rules of any
securities exchange or as may, consistently herewith, be determined by the
Trustee or the officers executing such Certificates, as evidenced by the
Trustee's or officer's execution of the Certificates (provided that such
letters, numbers or other marks of identification and such legends or
endorsements are in a form acceptable to the Company). At the Escrow Agent's
request under the Escrow Agreement, the Trustee shall affix the corresponding
Escrow Receipt to each Certificate. In any event, any transfer or exchange of
any Certificate shall also effect a transfer or exchange of the related Escrow
Receipt. Prior to the Final Withdrawal Date, no transfer or exchange of any
Certificate shall be permitted unless the Corresponding Escrow Receipt is
attached thereto and also is so transferred or exchanged. By acceptance of any
Certificate to which an Escrow Receipt is attached, each Holder of such a
Certificate acknowledges and accepts the restrictions on transfer of the Escrow
Receipt set forth herein and in the Escrow Agreement.

            (b) The Initial Certificates shall be issued only in fully
registered form without coupons and only in denominations of $100,000 or
integral multiples of $1,000 in excess
<PAGE>   24
                                      -19-


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 issued in the form of one or more Global Certificates
substantially in the form of Exhibit A hereto with such applicable legends as
are provided for in Section 3.02 (each a "Restricted Global Certificate") duly
executed and authenticated by the Trustee as hereinafter provided. Such
Restricted Global Certificates shall be in registered form and be registered in
the name of 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 issued in the form of one or more
global Certificates substantially in the form of Exhibit A hereto (each a
"Regulation S Global Certificate") duly executed and authenticated by the
Trustee as hereinafter provided. Such Regulation S Global Certificates shall be
in registered form and be registered in the name of 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 are first offered to persons other than distributors (as defined in
Regulation S) in reliance on Regulation S and (ii) the date of the closing of
the offering under the Certificate Purchase Agreement. The aggregate principal
amount of any Regulation S Global Certificate may from time to time be increased
or decreased by adjustments made on the records of the Trustee, as custodian for
DTC for such Global Certificate, as provided in Section 3.06 hereof, which
adjustments shall be conclusive as to the aggregate principal amount of any such
Global Certificate. The Restricted Global Certificate and Regulation S Global
Certificate are sometimes collectively referred to herein as the "Global
Certificates".

            (e) Initial Certificates offered and sold to any Institutional
Accredited Investor which is not a QIB in a transaction exempt from registration
under the Securities Act (and other than as described in Section 3.01(d)) shall
be issued substantially in the form of Exhibit A hereto in definitive, fully
registered form without interest coupons with such applicable legends as are
provided for in Section 3.02 (the "Restricted Definitive Certificates") duly
executed and authenticated by the Trustee as hereinafter provided. Certificates
issued pursuant to Section 3.05(b) in exchange for interests in a Regulation S
Global Certificate shall be issued in definitive, fully registered form without
interest coupons (the "Regulation S Definitive
<PAGE>   25
                                      -20-


Certificates"). The Restricted Definitive Certificates and the Regulation S
Definitive Certificates are sometimes collectively referred to herein as the
"Definitive Certificates".

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

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

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

            THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE U.S. SECURITIES
            ACT OF 1933, AS AMENDED (THE "SECURITIES ACT"), AND ACCORDINGLY, MAY
            NOT BE OFFERED OR SOLD WITHIN THE UNITED STATES OR TO, OR FOR THE
            ACCOUNT OR BENEFIT OF, ANY PERSONS EXCEPT AS SET FORTH IN THE
            FOLLOWING SENTENCE. BY ITS ACQUISITION HEREOF, THE HOLDER (1)
            REPRESENTS THAT (A) IT IS A "QUALIFIED INSTITUTIONAL BUYER" (AS
            DEFINED IN RULE 144A UNDER THE SECURITIES ACT), (B) IT IS AN
            INSTITUTIONAL "ACCREDITED INVESTOR" (AS DEFINED IN RULE 501(a)(1),
            (2), (3) OR (7) OF REGULATION D UNDER THE SECURITIES ACT) (AN
            "INSTITUTIONAL ACCREDITED INVESTOR") OR (C) IT IS NOT A U.S. PERSON
            AND IS ACQUIRING THIS CERTIFICATE IN AN OFFSHORE TRANSACTION IN
            COMPLIANCE WITH REGULATION S UNDER THE SECURITIES ACT; (2) AGREES
            THAT IT WILL NOT WITHIN TWO YEARS AFTER THE LATER OF THE ORIGINAL
            ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS
            CERTIFICATE
<PAGE>   26
                                      -21-


            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.

            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
<PAGE>   27
                                      -22-


            IN SECTIONS 3.05 AND 3.06 OF THE PASS THROUGH TRUST AGREEMENT
            REFERRED TO HEREIN.

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

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

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

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

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

            A Certificateholder may transfer a Certificate, or request that a
Certificate be exchanged for Certificates in an aggregate Fractional Undivided
Interest equal to the Fractional Undivided Interest of such Certificate
surrendered for exchange of other authorized denominations, by surrender of such
Certificate to the Trustee with the form of transfer notice thereon duly
completed and executed, and otherwise complying with the terms of this
Agreement, including providing evidence of compliance with any restrictions on
transfer, in form satisfactory to the Trustee and the Registrar; provided that
no exchanges of Initial Certificates for Exchange Certificates shall occur until
an Exchange Offer Registration Statement shall have been declared effective by
the SEC (notice of which shall be provided to the Trustee by the Company). No
such transfer shall be effected until, and such transferee shall succeed to
<PAGE>   28
                                      -23-


the rights of a Certificateholder only upon, final acceptance and registration
of the transfer by the Registrar in the Register. Prior to the registration of
any transfer by a Certificateholder as provided herein, the Trustee shall treat
the person in whose name the Certificate is registered as the owner thereof for
all purposes, and the Trustee shall not be affected by notice to the contrary.
Furthermore, DTC shall, by acceptance of a Global Certificate, agree that
transfers of beneficial interests in such Global Certificate may be effected
only through a book-entry system maintained by DTC (or its agent) and that
ownership of a beneficial interest in the Certificate shall be required to be
reflected in a book-entry. When Certificates are presented to the Registrar with
a request to register the transfer thereof or to exchange them for other
authorized denominations of a Certificate in a Fractional Undivided Interest
equal to the aggregate Fractional Undivided Interest of Certificates surrendered
for exchange, the Registrar shall register the transfer or make the exchange as
requested if its requirements for such transactions are met.

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

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

            (b) Transfers of any Global Certificate shall be limited to
transfers of such Restricted Global Certificate or Regulation S Global
Certificate in whole, but not in part, to DTC. Beneficial interests in the
Restricted Global Certificate and any Regulation S Global Certificate may be
transferred in accordance with the rules and procedures of DTC and the
provisions of Section 3.06. Beneficial interests in a Restricted Global
Certificate or a Regulation S Global Certificate shall be delivered to all
beneficial owners thereof in the form of Restricted Definitive Certificates or
Regulation S Definitive Certificates, as the case may be, if (i) DTC notifies
the Trustee that it is unwilling or unable to continue as depositary for such
Restricted Global Certificate or Regulation S Global Certificate, as the case
may be, and a successor depositary is not appointed by the Trustee within 90
days of such notice, and (ii) after the occurrence and during the continuance of
an Event of Default, owners of beneficial interests in a Global Certificate with
Fractional Undivided Interests aggregating not less than a majority in interest
in the Trust advise the Trustee, the Company and DTC through Agent Members in
<PAGE>   29
                                      -24-


writing that the continuation of a book-entry system through DTC or its
successor is no longer in their best interests.

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

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

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

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

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

            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
<PAGE>   30
                                      -25-


      Certificate to any Institutional Accredited Investor which is neither a
      QIB nor a Non-U.S. Person:

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

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

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

                        (i) If the Certificate to be transferred consists of
            Restricted Definitive Certificates, or of an interest in any
            Regulation S Global Certificate during the Restricted Period, the
            Registrar shall register the transfer if such transfer is being made
            by a proposed transferor who has checked the box provided for on the
            form 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.
<PAGE>   31
                                      -26-



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

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

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

                        (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.
<PAGE>   32
                                      -27-



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

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

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

            Section 3.07. Mutilated, Destroyed, Lost or Stolen Certificates. If
(a) any mutilated Certificate is surrendered to the Registrar or the Registrar
receives evidence to its satisfaction of the destruction, loss or theft of any
Certificate and (b) there is delivered to the Registrar and the Trustee such
security, indemnity or bond, as may be required by them to save each of them
harmless, then, in the absence of notice to the Registrar or the Trustee that
such destroyed, lost or stolen Certificate has been acquired by a protected
purchaser, and provided that the requirements of Section 8-405 of the Uniform
Commercial Code in effect in any applicable 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>   33
                                      -28-



            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>   34
                                      -29-


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

            (b) The Trustee shall establish and maintain on behalf of the
Certificateholders a Special Payments Account as one or more accounts, which
shall be non-interest bearing except as provided in Section 4.04. The Trustee
shall hold the Special Payments Account in trust for the benefit of the
Certificateholders and shall make or permit withdrawals therefrom only as
provided in this Agreement. On each day when one or more Special Payments are
made to the Trustee under the Intercreditor Agreement and upon the payment of
the Special Redemption Premium to the Trustee under the Note Purchase Agreement,
the Trustee, upon
<PAGE>   35
                                      -30-


receipt thereof, shall immediately deposit the aggregate amount of such Special
Payments in the Special Payments Account.

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

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

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

            (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>   36
                                      -31-


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>   37
                                      -32-



            (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 Delivery Period Termination Date, if
there has been any change in the information set forth in clauses (x), (y) and
(z) below from that set forth in page 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 Delivery Period
Termination Date, the Trustee will request from DTC a securities position
listing setting forth the names of all Agent Members reflected on DTC's books as
holding interests in the Certificates on such date. The Trustee will mail to
each such Agent Member the statement described above and will make available
additional copies as requested by such Agent Member for forwarding to holders of
interests in the Certificates.

            Section 4.04. Investment of Special Payment Moneys. Any money
received by the Trustee pursuant to Section 4.01(b) representing a Special
Payment which is not distributed on the date received shall, to the extent
practicable, be invested in Permitted Investments by the Trustee pending
distribution of such Special Payment pursuant to Section 4.02. Any investment
made pursuant to this Section 4.04 shall be in such Permitted Investments having
maturities not later than the date that such moneys are required to be used to
make the payment required under Section 4.02 on the applicable Special
Distribution Date and the Trustee shall hold any such Permitted Investments
until maturity. The Trustee shall have no liability with respect to any
<PAGE>   38
                                      -33-


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>   39
                                      -34-


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, then such
      other Certificateholder shall lose its right to purchase the Class C
      Certificates pursuant to this 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>   40
                                      -35-


      the Class G Certificates pursuant to clause (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>   41
                                      -36-


      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, 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,
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>   42
                                      -37-


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>   43
                                      -38-


      evidencing Fractional Undivided Interests aggregating not less than a
      majority in interest in the Trust.

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

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


                                   ARTICLE VII

                                   THE TRUSTEE

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

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

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

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

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

            (d) Whether or not herein expressly so provided, every provision of
this Trust Agreement relating to the conduct or affecting the liability of or
affording protection to the Trustee shall be subject to the provisions of this
Section.
<PAGE>   44
                                      -39-



            Section 7.02. Notice of Defaults. As promptly as practicable after,
and in any event within 90 days after, the occurrence of any default (as such
term is defined below) hereunder, the Trustee shall transmit by mail to the
Company, the Owner Trustees, the Owner Participants, the Loan Trustees and the
Certificateholders in accordance with Section 313(c) of the Trust Indenture Act,
notice of such default hereunder known to the Trustee, unless such default shall
have been cured or waived; provided, however, that, except in the case of a
default on the payment of the principal, premium, if any, 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>   45
                                      -40-



            (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>   46
                                      -41-

            (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>   47
                                      -42-


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>   48
                                      -43-



            (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>   49
                                      -44-


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>   50
                                      -45-


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>   51
                                      -46-



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

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

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

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

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

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

            (e) this Agreement, the Intercreditor Agreement, the Registration
Rights Agreement, the Escrow Agreement, the Note Purchase Agreement, and the
Financing Documents to which it is a party have been duly executed and delivered
by the Trustee and constitute the legal, valid, and binding agreements of the
Trustee, enforceable against it in
<PAGE>   52
                                      -47-


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 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
<PAGE>   53
                                      -48-


no such list need be furnished for so long as a copy of the Register is being
furnished to the Trustee pursuant to Section 7.12.

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

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

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

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

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

            (c) file with the Trustee and the SEC, in accordance with the rules
      and regulations prescribed by the SEC, such additional information,
      documents and reports with respect to compliance by the Company with the
      conditions and covenants provided for in this Agreement, as may be
      required by such rules and regulations, including, in the case of annual
      reports, if required by such rules and regulations, certificates or
      opinions of independent public accountants, conforming to the requirements
      of Section 1.02;
<PAGE>   54
                                      -49-



            (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 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
<PAGE>   55
                                      -50-


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

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

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

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

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

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

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



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

            Section 9.04. Execution of Supplemental Agreements. In executing, or
accepting the additional trusts created by, any agreement permitted by this
Article or the modifications thereby of the trusts created by this Agreement,
the Trustee shall be entitled to receive, and shall be fully protected in
relying upon, an Opinion of Counsel stating that the execution of such
supplemental agreement is authorized or permitted by this Agreement.
<PAGE>   57
                                      -52-



            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 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
<PAGE>   58
                                      -53-


gives such consent. Notwithstanding the foregoing, but subject to Section 6.04
and the Intercreditor Agreement, the Trustee may, in its own discretion and at
its own direction, consent and notify the relevant Loan Trustee of such consent
(or direct the Subordination Agent to consent and notify the Loan Trustee of
such consent) to any amendment, modification, waiver or supplement under the
relevant Indenture, any other Financing Document, any Equipment Note or any
other related document, if an Event of Default hereunder shall have occurred and
be continuing, or if such amendment, modification, waiver or supplement will not
materially adversely affect the interests of the Certificateholders.


                                   ARTICLE XI

                              TERMINATION OF TRUST

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

            Upon the earlier of (i) the first Business Day after August 30,
2002, or, if later, the fifth Business Day following the Delivery Period
Termination Date and (ii) the fifth Business Day following the date on which a
Triggering Event occurs (such date, the "Transfer Date"), or, if later the date
on which all of the conditions set forth in the immediately following sentence
have been satisfied, the Trustee is hereby directed (subject only to the
immediately following sentence) to, and the Company shall direct the institution
that will serve as the Related Trustee under the Related Pass Through Trust
Agreement to, execute and deliver the Assignment and Assumption Agreement,
pursuant to which the Trustee shall assign, transfer and deliver all of the
Trustee's right, title and interest to the Trust Property to the Related Trustee
under the Related Pass Through Trust Agreement. The Trustee and the Related
Trustee shall execute and deliver the Assignment and Assumption Agreement upon
the satisfaction of the following conditions:

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

            (a)         upon the execution and delivery thereof by the parties
                        thereto in accordance with the terms of this Agreement
                        and the Related Pass Through Trust Agreement, the
                        Assignment and Assumption Agreement will constitute the
                        valid and binding obligation of each of the parties
                        thereto enforceable against each such party in
                        accordance with its terms;
<PAGE>   59
                                      -54-



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

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

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

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

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

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

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

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

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


                                   ARTICLE XII

                            MISCELLANEOUS PROVISIONS

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

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

            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
<PAGE>   61
                                      -56-


any such notice shall be effective when received or, if made, given, furnished
or filed by facsimile or telecommunication transmission, when received unless
received outside of business hours, in which case on the next open of business
on a Business Day,

                  if to the Company, to:

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

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


                  if to the Trustee, to:

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

                           Attention:  Corporate Trust 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.
<PAGE>   62
                                      -57-



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

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

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

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

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

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

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

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



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



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


                                AMERICA WEST AIRLINES, INC.


                                By:    /s/ 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>   65
                                                                       EXHIBIT A

                               FORM OF CERTIFICATE

REGISTERED

No._________

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

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

         BY ITS ACQUISITION HEREOF, THE HOLDER REPRESENTS THAT (A) NO PLAN
         ASSETS HAVE BEEN USED TO PURCHASE THIS CERTIFICATE OR AN INTEREST
         HEREIN OR (B) THE PURCHASE AND HOLDING OF THIS CERTIFICATE OR AN
         INTEREST HEREIN IS EXEMPT FROM THE PROHIBITED TRANSACTION RESTRICTIONS
         OF ERISA AND THE CODE PURSUANT TO ONE OR MORE PROHIBITED TRANSACTION
         STATUTORY OR ADMINISTRATIVE EXEMPTIONS. THE PASS THROUGH TRUST
         AGREEMENT CONTAINS A PROVISION REQUIRING THE TRUSTEE TO REFUSE TO
         REGISTER ANY TRANSFER OF THIS CERTIFICATE IN VIOLATION OF THE FOREGOING
         RESTRICTIONS.

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

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

-----------------

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

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

                             [GLOBAL CERTIFICATE]*

           AMERICA WEST AIRLINES PASS THROUGH TRUST, SERIES 2001-1D-O

            Floating Rate America West Airlines [Initial] [Exchange]
                            Pass Through Certificate,
                                Series 2001-1D-O

                 Final Legal Distribution Date: October 2, 2005

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

         having a face amount of $[       ] representing [         ]% of the
Trust per $1,000 face amount

         THIS CERTIFIES THAT _______________, for value received, is the
registered owner of a Fractional Undivided Interest, having a face amount of
$________ (__________dollars) in the America West Airlines Pass Through Trust,
Series 2001-1D-O (the "Trust") created pursuant to a Pass Through Trust
Agreement, dated as of May 17, 2001 (the "Agreement"), between Wilmington Trust
Company (the "Trustee") and America West Airlines, Inc., a corporation
incorporated under Delaware law (the "Company"), a summary of certain of the
pertinent provisions of which is set forth below. To the extent not otherwise
defined herein, the capitalized terms used herein have the meanings assigned to
them in the Agreement. This Certificate is one of the duly authorized
Certificates designated as "Floating Rate America West Airlines [Initial]
[Exchange] Pass Through Certificates, Series 2001-1D-O" (herein called the
"Certificates"). This Certificate is issued under and is subject to the terms,
provisions, and conditions of the Agreement. By virtue of its acceptance hereof
the Certificateholder of this Certificate assents to and agrees to be bound by
the provisions of the Agreement and the Intercreditor Agreement. The property of
the Trust includes an interest in certain Equipment Notes and all rights of the
Trust to receive payments under the Intercreditor Agreement (the "Trust
Property"). Each issue of the Equipment Notes is secured by, among other things,
a security interest in the Aircraft leased to or owned by the Company.

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

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

         Subject to and in accordance with the terms of the Agreement and the
Intercreditor Agreement, from and to the extent of funds then available to the
Trustee, there will be distributed on each April 2, and October 2, (a "Regular
Distribution Date"), commencing on October 2, 2001, to the Person in whose name
this Certificate is registered at the close of business on the 15th day
preceding the Regular Distribution Date, an amount in respect of the Scheduled
Payments due on such Regular Distribution Date on the Equipment Notes, the
receipt of which has been confirmed by the Trustee, equal to the product of the
percentage interest in the Trust evidenced by this Certificate and an amount
equal to the sum of such Scheduled Payments. Subject to and in accordance with
the terms of the Agreement and the Intercreditor Agreement, in the event that
Special Payments on the Equipment Notes are received by the Trustee, from funds
then available to the Trustee, there shall be distributed on the applicable
Special Distribution Date, to the Person in whose name this Certificate is
registered at the close of business on the 15th day preceding the Special
Distribution Date, an amount in respect of such Special Payments on the
Equipment Notes, the receipt of which has been confirmed by the Trustee, equal
to the product of the percentage interest in the Trust evidenced by this
Certificate and an amount equal to the sum of such Special Payments so received.
If a Regular Distribution Date or Special Distribution Date is not a Business
Day, distribution shall be made on the immediately following Business Day with
the same force and effect as if made on such Regular Distribution Date or
Special Distribution Date and no interest shall accrue during the intervening
period. The Trustee shall mail notice of each Special Payment and the Special
Distribution Date therefor to the Certificateholder of this Certificate.

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

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

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

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

         [The Holder of this Certificate is entitled to the benefits of the
Exchange and Registration Rights Agreement, dated as of May 17, 2001, among the
Company, the Trustee and the Initial Purchasers named therein (the "Registration
Rights Agreement"). In the event that no Registration Event has occurred on or
prior to the 210th day after the date of the issuance of the Certificates, the
interest rate per annum payable in respect of the Equipment Notes and the
Deposits shall be increased by 0.50%, from and including the 210th day after the
Issuance Date to but excluding the earlier of (i) the date on which a
Registration Event occurs and (ii) the date on which there cease to be any
Registrable Certificates (as defined in the Registration Rights Agreement). In
the event that the Shelf Registration Statement ceases to be effective at any
time during the period specified by Section 2(b)(B) of the Registration Rights
Agreement for more than 60 days, whether or not consecutive, during any 12-month
period, the interest rate per annum payable in respect of the Equipment Notes
and the Deposits shall be increased by 0.50% from the 61st day of the applicable
12-month period such Shelf Registration Statement ceases to be effective until
such time as the Shelf Registration Statement again becomes effective (or, if
earlier, the end of the period specified by Section 2(b)(B) of the Registration
Rights Agreement).]*

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

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

---------------

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

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

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

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

         Each Certificateholder and Investor, by its acceptance of this
Certificate or a beneficial interest herein, agrees to treat the Trust as a
grantor trust for all U.S. federal, state and local income tax purposes.

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

         The obligations and responsibilities created by the Agreement and the
Trust created thereby shall terminate upon the distribution to
Certificateholders of all amounts required to be distributed to them pursuant to
the Agreement and the disposition of all property held as part of the Trust
Property.

-----------------------

*        To be included only on each Initial Certificate.

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



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

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

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

Dated:

                                   AMERICA WEST AIRLINES PASS THROUGH
                                   TRUST, SERIES 2001-1D-O



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


                                   By:
                                      ----------------------------------------
                                         Name:
                                         Title:
<PAGE>   73
                                      A-9


              [FORM OF THE TRUSTEE'S CERTIFICATE OF AUTHENTICATION]

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



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


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

                             FORM OF TRANSFER NOTICE

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

Insert Taxpayer Identification No.


--------------------------------

--------------------------------

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

--------------------------------

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

--------------------------------

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

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

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

                                   [Check One]

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

                                       or

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

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



Date:__________________                              [Name of Transferor]

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

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

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

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

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

                                                     [date]

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

Attention:  Corporate Trust Trustee Administration

         Re:      America West Airlines Pass Through Trust (the "Trust"), Series
                  2001-1D-O, America West Airlines Pass Through Certificates,
                  Series 2001-1D-O (the "Certificates")

Ladies and Gentlemen:

         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>   77
                                      B-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>   78
                                                                       EXHIBIT C

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

                                                   [date]

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


Attention:  Corporate Trust Trustee Administration

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


                              AMERICA WEST AIRLINES
               PASS THROUGH TRUST, SERIES 2001-1D-O (the "Trust")
                   Pass Through Certificates, Series 2001-1D-O
                              (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>   79
                                      C-2

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

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

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

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

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

                                  Very truly yours,



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

                   FORM OF ASSIGNMENT AND ASSUMPTION AGREEMENT
                America West Airlines Pass Through Trust, Series
                                    2001-1D-O


         ASSIGNMENT AND ASSUMPTION AGREEMENT, dated ____________, _____ (the
"Agreement"), between Wilmington Trust Company, a Delaware banking corporation
("WTC"), not in its individual capacity except as expressly provided herein, but
solely as trustee under the Pass Through Trust Agreement dated as of May 17,
2001 (as amended, modified or otherwise supplemented from time to time, the
"Pass Through Trust Agreement") in respect of the America West Airlines Pass
Through Trust, Series 2001-1D-O (the "Assignor"), and Wilmington Trust Company,
a Delaware banking corporation, not in its individual capacity except as
expressly provided herein, but solely as trustee under the Pass Through Trust
Agreement dated as of May 17, 2001 (the "New Pass Through Trust Agreement") in
respect of the America West Airlines Pass Through Trust, Series 2001-1D-S (the
"Assignee").

                              W I T N E S S E T H:

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

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

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

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

         2. Assumption. The Assignee hereby assumes for the benefit of the
Assignor and each of the parties listed in Schedule II hereto (collectively, the
"Beneficiaries") all of the duties and obligations of the Assignor, whenever
accrued, pursuant to the Assigned Documents and hereby confirms that it shall be
deemed a party to each of the Assigned Documents to which the Assignor is a
party and shall be bound by all the terms thereof (including the agreements and
obligations of the Assignor set forth therein) as if therein named as the
Assignor. Further, the
<PAGE>   81
                                      D-2

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

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

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

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

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

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

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

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

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

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

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

      applicable bankruptcy, insolvency, reorganization, moratorium or similar
      laws affecting the rights of creditors generally and by general principles
      of equity, whether considered in a proceeding at law or in equity.

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

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

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

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

                                    ASSIGNOR:

                                                     WILMINGTON TRUST COMPANY,
                                                     not in its individual
                                                     capacity except as
                                                     expressly provided herein,
                                                     but solely as trustee under
                                                     the Pass Through Trust
                                                     Agreement in respect of the
                                                     America West Airlines Pass
                                                     Through Trust 2001-1D-O


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

                                    ASSIGNEE:

                                                     WILMINGTON TRUST COMPANY,
                                                     not in its individual
                                                     capacity except as
                                                     expressly provided herein,
                                                     but solely as trustee under
                                                     the Pass Through Trust
                                                     Agreement in respect of the
                                                     America West Airlines Pass
                                                     Through Trust 2001-1D-S


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

                         Schedule of Assigned Documents

(1)      Intercreditor Agreement dated as of May 17, 2001 among the Trustee, the
         Other Trustees, the Policy Provider, the Liquidity Provider, the
         liquidity provider, if any, relating to the Certificates issued under
         (and as defined in) the Other Pass Through Trust Agreements and the
         Subordination Agent.

(2)      Registration Rights Agreement dated as of May 17, 2001 among the
         Initial Purchasers, the Trustee, the Other Trustees, and the Company.

(3)      Escrow and Paying Agent Agreement (Class D) dated as of May 17, 2001
         among the Escrow Agent, the Initial Purchasers, the Trustee and the
         Paying Agent.

(4)      Note Purchase Agreement dated as of May 17, 2001 among the Company, the
         Trustee, the Other Trustees, the Depositary, the Escrow Agent, the
         Paying Agent and the Subordination Agent.

(5)      Deposit Agreement (Class D) dated as of May 17, 2001 between the Escrow
         Agent and the Depositary.

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

                            Schedule of Beneficiaries

Wilmington Trust Company, not in its individual capacity but solely as Pass
         Through Trustee, Subordination Agent, Paying Agent and Escrow Agent

Ambac Assurance Corporation, as Policy Provider

Westdeutsche Landesbank Girozentrale, as Liquidity Provider

Citibank, N.A., as Depositary

America West Airlines, Inc.

Salomon Smith Barney Inc.

Deutsch Banc Alex. Brown Inc.

Mizuho International plc

Banc One Capital Markets, Inc.

Tokyo-Mitsubishi International plc

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

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

                                                                          [DATE]

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

         Re:      America West Airlines Pass Through Trust, Series 2001-1D-O
                  Pass Through Certificates, Series 2001-1D-O

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

                                                              Very truly yours,