<PAGE>   1
                                                                       EXECUTION



                                                                    Exhibit 4.11


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                           REVOLVING CREDIT AGREEMENT
                                    (1998-1B)


                           Dated as of October 6, 1998

                                     between

                            WILMINGTON TRUST COMPANY,

                    not in its individual capacity but solely
                             as Subordination Agent,
                          as agent and trustee for the
                America West Airlines Pass Through Trust 1998-1B

                                   as Borrower

                                       and

                       ABN AMRO BANK N.V., CHICAGO BRANCH

                              as Liquidity Provider

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                                   Relating to

                America West Airlines Pass Through Trust 1998-1B
             7.12% America West Airlines Pass Through Certificates,
                                 Series 1998-1B
<PAGE>   2
                                TABLE OF CONTENTS

<TABLE>
<CAPTION>
                                                                                                               Page
                                                                                                               ----
<S>                 <C>                                                                                        <C>
                              ARTICLE I DEFINITIONS
     Section 1.01.  Certain Defined Terms. .......................................................................1

                      ARTICLE II AMOUNT AND TERMS OF THE COMMITMENT
     Section 2.01.  The Advances. ................................................................................7
     Section 2.02.  Making the Advances. .........................................................................7
     Section 2.03.  Fees. ........................................................................................8
     Section 2.04.  Reduction or Termination of the Maximum Commitment. ..........................................8
     Section 2.05.  Repayments of Interest Advances or the Final Advance. ........................................9
     Section 2.06.  Repayments of Provider Advances. .............................................................9
     Section 2.07.  Payments to the Liquidity Provider Under the Intercreditor Agreement. .......................10
     Section 2.08.  Book Entries. ...............................................................................10
     Section 2.09.  Payments from Available Funds Only. .........................................................11
     Section 2.10.  Extension of the Expiry Date; Non-Extension Advance. ........................................11

                     ARTICLE III OBLIGATIONS OF THE BORROWER
     Section 3.01.  Increased Costs. ............................................................................12
     Section 3.02.  Capital Adequacy. ...........................................................................13
     Section 3.03.  Payments Free of Deductions. ................................................................14
     Section 3.04.  Payments. ...................................................................................14
     Section 3.05.  Computations. ...............................................................................14
     Section 3.06.  Payment on Non-Business Days. ...............................................................15
     Section 3.07.  Interest. ...................................................................................15
     Section 3.08.  Replacement of Borrower. ....................................................................16
     Section 3.09.  Funding Loss Indemnification. ...............................................................16
     Section 3.10.  Illegality. .................................................................................16

                         ARTICLE IV CONDITIONS PRECEDENT
     Section 4.01.  Conditions Precedent to Effectiveness of Section 2.01. ......................................17
     Section 4.02.  Conditions Precedent to Borrowing. ..........................................................18

                               ARTICLE V COVENANTS
     Section 5.01.  Affirmative Covenants of the Borrower. ......................................................18
     Section 5.02.  Negative Covenants of the Borrower. .........................................................19

                     ARTICLE VI LIQUIDITY EVENTS OF DEFAULT
     Section 6.01.  Liquidity Events of Default. ................................................................19

                            ARTICLE VII MISCELLANEOUS
     Section 7.01.  Amendments, Etc. ............................................................................19
     Section 7.02.  Notices, Etc. ...............................................................................20
     Section 7.03.  No Waiver; Remedies. ........................................................................20
     Section 7.04.  Further Assurances. .........................................................................21
     Section 7.05.  Indemnification; Survival of Certain Provisions. ............................................21
     Section 7.06.  Liability of the Liquidity Provider. ........................................................21
</TABLE>
                                       i
<PAGE>   3
                                TABLE OF CONTENTS
                                  (CONTINUED)

<TABLE>
<CAPTION>
<S>                 <C>                                                                                        <C>
     Section 7.07.  Costs, Expenses and Taxes. ..................................................................21
     Section 7.08.  Binding Effect; Participations. .............................................................22
     Section 7.09.  Severability. ...............................................................................23
     Section 7.10.  Governing Law. ..............................................................................23
     Section 7.11.  Submission to Jurisdiction; Waiver of Jury Trial; Waiver of Immunity. .......................23
     Section 7.12.  Execution in Counterparts. ..................................................................24
     Section 7.13.  Entirety. ...................................................................................24
     Section 7.14.  Headings. ...................................................................................24
     Section 7.15.  Transfer. ...................................................................................25
     Section 7.16.  Liquidity Provider's Obligation To Make Advances. ...........................................25
</TABLE>

                                       ii
<PAGE>   4
                                TABLE OF CONTENTS
                                   (CONTINUED)


ANNEX I                  Interest Advance Notice of Borrowing

ANNEX II                 Non-Extension Advance Notice of Borrowing

ANNEX III                Downgrade Advance Notice of Borrowing

ANNEX IV                 Final Advance Notice of Borrowing

ANNEX V                  Notice of Termination

ANNEX VI                 Notice of Replacement Subordination Agent

                                      iii
<PAGE>   5
                           REVOLVING CREDIT AGREEMENT

                  This REVOLVING CREDIT AGREEMENT dated as of October 6, 1998,
between WILMINGTON TRUST COMPANY, a Delaware banking corporation, not in its
individual capacity but solely as Subordination Agent under the Intercreditor
Agreement (each as defined below), as agent and trustee for the Class B Trust
(as defined below) (the "Borrower"), and ABN AMRO BANK N.V., a bank organized
under the laws of the Netherlands, acting through its Chicago branch (the
"Liquidity Provider").

                              W I T N E S S E T H:

                  WHEREAS, pursuant to the Class B Trust Agreement (such term
and all other capitalized terms used in these recitals having the meanings set
forth or referred to in Section 1.01), the Class B Trust is issuing the Class B
Certificates; and

                  WHEREAS, the Borrower, in order to support the timely payment
of a portion of the interest on the Class B Certificates in accordance with
their terms, has requested the Liquidity Provider to enter into this Agreement,
providing in part for the Borrower to request in specified circumstances that
Advances be made hereunder.

                  NOW, THEREFORE, in consideration of the premises, the parties
hereto agree as follows:


                                    ARTICLE I

                                   DEFINITIONS

                  Section 1.01. Certain Defined Terms. (a) Definitions. As used
in this Agreement and unless otherwise expressly indicated, or unless the
context clearly requires otherwise, the following capitalized terms shall have
the following respective meanings for all purposes of this Agreement:

                  "Additional Cost" has the meaning assigned to such term in
         Section 3.01.

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

                  "Applicable Liquidity Rate" has the meaning assigned to such
         term in Section 3.07(g).

                  "Applicable Margin" means (A) with respect to any Unpaid
         Advance or Applied Provider Advance, (x) with respect to any LIBOR
         Advance, 1.75% and (y) with respect to any Base Rate Advance, 1%, and
         (B) with respect to any Unapplied Provider Advance, (x) with respect to
         any LIBOR Advance, .35% and (y) with respect to any Base Rate Advance,
         0.
<PAGE>   6
                                                                               2

                  "Applied Downgrade Advance" has the meaning assigned to such
         term in Section 2.06(a).

                  "Applied Non-Extension Advance" has the meaning assigned to
         such term in Section 2.06(a).

                  "Applied Provider Advance" has the meaning assigned to such
         term in Section 2.06(a).

                  "Assignment and Assumption Agreement" means the Assignment and
         Assumption to be entered into between the Borrower and the trustee of
         the Successor Trust, substantially in the form of Exhibit D to the
         Class B Trust Agreement.

                  "Base Rate" means a fluctuating interest rate per annum in
         effect from time to time, which rate per annum shall at all times be
         equal to (a) the weighted average of the rates on overnight Federal
         funds transactions with members of the Federal Reserve System arranged
         by Federal funds brokers, as published for such day (or, if such day is
         not a Business Day, for the next preceding Business Day) by the Federal
         Reserve Bank of New York, or if such rate is not so published for any
         day that is a Business Day, the average of the quotations for such day
         for such transactions received by the Liquidity Provider from three
         Federal funds brokers of recognized standing selected by it, plus (b)
         one quarter of one percent (1/4 of 1%).

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

                  "Borrower" has the meaning assigned to such term in the
         recital of parties to this Agreement.

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

                  "Business Day" means any day other than a Saturday or Sunday
         or a day on which commercial banks are required or authorized to close
         in Phoenix, Arizona, New York, New York, Chicago, Illinois or, so long
         as any Class B Certificate is outstanding, the city and state in which
         the Class B Trustee, the Borrower or any Loan Trustee maintains its
         Corporate Trust Office or receives or disburses funds, and, if the
         applicable Business Day relates to any Advance or other amount bearing
         interest based on the LIBOR Rate, on which dealings are carried on in
         the London interbank market.

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

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

                  "Deposit Agreement" means the Deposit Agreement dated October
         6, 1998 between Wilmington Trust Company, as Escrow Agent and ABN AMRO
         Bank N.V., acting through its Chicago branch, as Depositary, pertaining
         to the Class B Certificates,
<PAGE>   7
                                                                               3

         as the same may be amended, modified or supplemented from time to time
         in accordance with the terms thereof.

                  "Downgrade Advance" means an advance made pursuant to Section
         2.02(c).

                  "Effective Date" has the meaning specified in Section 4.01.
         The delivery of the certificate of the Liquidity Provider contemplated
         by Section 4.01(e) shall be conclusive evidence that the Effective Date
         has occurred.

                  "Excluded Taxes" means (i) taxes imposed on the overall net
         income, net worth, capital or franchise of the Liquidity Provider or of
         its Lending Office by the jurisdiction where such Liquidity Provider's
         principal office or such Lending Office is located, and (ii) Excluded
         Withholding Taxes.

                  "Excluded Withholding Taxes" means (i) withholding Taxes
         imposed by the United States except (but only in the case of a
         successor Liquidity Provider organized under the laws of a jurisdiction
         outside the United States) to the extent that such United States
         withholding Taxes are imposed as a result of any change in applicable
         law (excluding from change in applicable law for this purpose a change
         in an applicable treaty or other change in law affecting the
         applicability of a treaty) after the date hereof, or in the case of a
         successor Liquidity Provider (including a transferee of an Advance) or
         Lending Office, after the date on which such successor Liquidity
         Provider obtains its interest or on which the Lending Office is
         changed, and (ii) any withholding Taxes imposed by the United States
         which are imposed or increased as a result of the Liquidity Provider
         failing to deliver to the Borrower any certificate or document (which
         certificate or document in the good faith judgment of the Liquidity
         Provider it is legally entitled to provide) which is reasonably
         requested by the Borrower to establish that payments under this
         Agreement are exempt from (or entitled to a reduced rate of)
         withholding Tax.

                  "Expenses" means liabilities, obligations, damages,
         settlements, penalties, claims, actions, suits, costs, expenses, and
         disbursements (including, without limitation, reasonable fees and
         disbursements of legal counsel and costs of investigation), provided
         that Expenses shall not include any Taxes.

                  "Expiry Date" means October 4, 1999, initially, or any date to
         which the Expiry Date is extended pursuant to Section 2.10.

                  "Final Advance" means an advance made pursuant to Section
         2.02(d).

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

                  "Interest Advance" means an advance made pursuant to Section
         2.02(a).
<PAGE>   8
                                                                               4

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

                  (i)      the period beginning on the third Business Day
                           following either (x) the Liquidity Provider's receipt
                           of the Notice of Borrowing for such LIBOR Advance
                           (or, in the case of an Unapplied Downgrade Advance,
                           the period beginning on the Expiry Date) or (y) the
                           withdrawal of funds from the Class B Cash Collateral
                           Account for the purpose of paying interest on the
                           Class B Certificates as contemplated by Section
                           2.06(a) hereof and, in either case, ending on the
                           next Regular Distribution Date; and

                  (ii)     each subsequent period commencing on the last day of
                           the immediately preceding Interest Period and ending
                           on the next Regular Distribution Date;

         provided, however, that if (x) the Final Advance shall have been made,
         or (y) other outstanding Advances shall have been converted into the
         Final Advance, then the Interest Periods shall be successive periods of
         one month beginning on the third Business Day following the Liquidity
         Provider's receipt of the Notice of Borrowing for such Final Advance
         (in the case of clause (x) above) or the last day of the Interest
         Period then applicable to such outstanding Advances (in the case of
         clause (y) above).

                  "Lending Office" means the office of the Liquidity Provider in
         which it books this facility presently located at Chicago, Illinois, or
         such other office as the Liquidity Provider from time to time shall
         notify the Borrower as its "Lending Office" hereunder in which it books
         this facility; provided that the Liquidity Provider shall not change
         its Lending Office to a Lending Office outside the United States of
         America except in accordance with Section 3.01, 3.02 or 3.03 hereof.

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

                  "LIBOR Rate" means, with respect to any Interest Period, the
         rate per annum appearing on Page 3750 of the Dow Jones Markets Service
         (or any successor or substitute Page of such Service, or any successor
         to or substitute for such Service, providing rate quotations comparable
         to those currently provided on such Page applicable to deposits in
         dollars in the London interbank market) at approximately 11:00 A.M.
         (London time) two Business Days before the first day of such Interest
         Period for a period of time comparable to such Interest Period. In the
         event that such rate is not available at such time for any reason, then
         the LIBOR Rate with respect to any Interest Period shall be the rate
         per annum at which deposits in dollars are offered to major banks in
         the London interbank market at approximately 11:00 A.M. (London time)
         two Business Days before the first day of such Interest Period for a
         period of time comparable to such Interest Period.

                  "Liquidity Event of Default" means the occurrence of either
         (a) the Acceleration of all of the Equipment Notes (provided that, with
         respect to the period prior to the Delivery Period Expiry Date, such
         Equipment Notes have an aggregate outstanding principal balance in
         excess of $125,000,000) or (b) an America West Bankruptcy Event.
<PAGE>   9
                                                                               5

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

                  "Liquidity Provider" has the meaning assigned to such term in
         the recital of parties to this Agreement.

                  "Maximum Available Commitment" means, subject to the proviso
         contained in the third sentence of Section 2.02(a), at any time of
         determination, (a) the Maximum Commitment at such time less (b) the
         aggregate amount of each Interest Advance outstanding at such time;
         provided that following a Provider Advance or a Final Advance, the
         Maximum Available Commitment shall be zero.

                  "Maximum Commitment" means initially $4,703,902, as the same
         may be reduced from time to time in accordance with Section 2.04(a).

                  "Non-Extension Advance" means an advance made pursuant to
         Section 2.02(b).

                  "Notice of Borrowing" has the meaning specified in Section
         2.02(e).

                  "Notice of Replacement Subordination Agent" has the meaning
         specified in Section 3.08.

                  "Offering Memorandum" means the Offering Memorandum dated
         September 24, 1998 relating to the Certificates, as such Offering
         Memorandum may be amended or supplemented.

                  "Performing Note Deficiency" means any time that less than 65%
         of the then aggregate outstanding principal amount of all Equipment
         Notes are Performing Equipment Notes.

                  "Provider Advance" means a Downgrade Advance or a
         Non-Extension Advance.

                  "Regulatory Change" has the meaning assigned to such term in
         Section 3.01.

                  "Replenishment Amount" has the meaning assigned to such term
         in Section 2.06(b).

                  "Required Amount" means, for any day, the sum of the aggregate
         amount of interest, calculated at the rate per annum equal to the
         Stated Interest Rate for the Class B Certificates, that would be
         payable on the Class B Certificates on each of the three successive
         semiannual Regular Distribution Dates immediately following such day
         or, if such day is a Regular Distribution Date, on such day and the
         succeeding two semiannual Regular Distribution Dates, in each case
         calculated on the basis of the Pool Balance of the Class B Certificates
         on such day and without regard to expected future payments of principal
         on the Class B Certificates.
<PAGE>   10
                                                                               6

                  "Successor Trust" means America West Airlines Pass Through
         Trust 1998-1B-S.

                  "Termination Date" means the earliest to occur of the
         following: (i) the Expiry Date; (ii) the date on which the Borrower
         delivers to the Liquidity Provider a certificate, signed by a
         Responsible Officer of the Borrower, certifying that all of the Class B
         Certificates have been paid in full (or provision has been made for
         such payment in accordance with the Intercreditor Agreement and the
         Trust Agreements) or are otherwise no longer entitled to the benefits
         of this Agreement; (iii) the date on which the Borrower delivers to the
         Liquidity Provider a certificate, signed by a Responsible Officer of
         the Borrower, certifying that a Replacement Liquidity Facility has been
         substituted for this Agreement in full pursuant to Section 3.6(e) of
         the Intercreditor Agreement; (iv) the fifth Business Day following the
         receipt by the Borrower of a Termination Notice from the Liquidity
         Provider pursuant to Section 6.01 hereof; and (v) the date on which no
         Advance is or may (including by reason of reinstatement as herein
         provided) become available for a Borrowing hereunder.

                  "Termination Notice" means the Notice of Termination
         substantially in the form of Annex V to this Agreement.

                  "Transferee" has the meaning assigned to such term in Section
         7.08(b).

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

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

                  "Unpaid Advance" has the meaning assigned to such term in
         Section 2.05.

                  (b) Terms Defined in the Intercreditor Agreement. For all
         purposes of this Agreement, the following terms shall have the
         respective meanings assigned to such terms in the Intercreditor
         Agreement:

         "Acceleration", "America West", "America West Bankruptcy Event",
         "Certificates", "Class A Certificates", "Class B Cash Collateral
         Account", "Class B Certificates", "Class B Certificateholders", "Class
         B Trust", "Class B Trust Agreement", "Class B Trustee", "Class C
         Certificates", "Closing Date", "Controlling Party", "Corporate Trust
         Office", "Delivery Period Expiry Date", "Distribution Date",
         "Downgraded Facility", "Equipment Notes", "Fee Letter", "Final Legal
         Distribution Date", "Financing Agreement", "Indenture", "Initial
         Purchasers", "Interest Payment Date", "Investment Earnings", "Liquidity
         Facility", "Liquidity Obligations", "Loan Trustee", "Moody's",
         "Non-Extended Facility", "Note Purchase Agreement", "Operative
         Agreements", "Performing Equipment Note", "Person", "Pool Balance",
         "Purchase Agreement", "Rating Agency", "Ratings Confirmation", "Regular
         Distribution Date", "Replacement Liquidity Facility", "Responsible
         Officer", "Scheduled Payment", "Special Payment", "Standard & Poor's",
         "Stated Interest Rate", "Subordination Agent", "Taxes", "Threshold
         Rating", "Transfer", "Trust Agreements", "Trustee", and "Written
         Notice".
<PAGE>   11
                                                                               7

                                   ARTICLE II

                       AMOUNT AND TERMS OF THE COMMITMENT

                  Section 2.01. The Advances. The Liquidity Provider hereby
irrevocably agrees, on the terms and conditions hereinafter set forth, to make
Advances to the Borrower from time to time on any Business Day during the period
from the Effective Date until 12:00 Noon (New York City time) on the Expiry Date
(unless the obligations of the Liquidity Provider shall be earlier terminated in
accordance with the terms of Section 2.04(b)) in an aggregate amount at any time
outstanding not to exceed the Maximum Commitment.

                  Section 2.02. Making the Advances. (a) Interest Advances shall
be made in one or more Borrowings by delivery to the Liquidity Provider of one
or more written and completed Notices of Borrowing in substantially the form of
Annex I attached hereto, signed by a Responsible Officer of the Borrower, in an
amount not exceeding the Maximum Available Commitment at such time and shall be
used solely for the payment when due of interest on the Class B Certificates at
the Stated Interest Rate therefor in accordance with Section 3.6(a) of the
Intercreditor Agreement. Each Interest Advance made hereunder shall
automatically reduce the Maximum Available Commitment by the amount of such
Interest Advance (subject to reinstatement as provided in the next sentence).
Upon repayment to the Liquidity Provider in full of the amount of any Interest
Advance made pursuant to this Section 2.02(a), together with accrued interest
thereon (as provided herein), the Maximum Available Commitment shall be
reinstated by the amount of such repaid Interest Advance, but not to exceed the
Maximum Commitment; provided, however, that the Maximum Available Commitment
shall not be so reinstated at any time if (i) a Liquidity Event of Default shall
have occurred and be continuing and (ii) there is a Performing Note Deficiency.

                  (b) A Non-Extension Advance shall be made in a single
Borrowing if this Agreement is not extended in accordance with Section 3.6(d) of
the Intercreditor Agreement (unless a Replacement Liquidity Facility to replace
this Agreement shall have been delivered to the Borrower as contemplated by said
Section 3.6(d) within the time period specified in such Section) by delivery to
the Liquidity Provider of a written and completed Notice of Borrowing in
substantially the form of Annex II attached hereto, signed by a Responsible
Officer of the Borrower, in an amount equal to the Maximum Available Commitment
at such time, and shall be used to fund the Class B Cash Collateral Account in
accordance with said Section 3.6(d) and Section 3.6(f) of the Intercreditor
Agreement.

                  (c) A Downgrade Advance shall be made in a single Borrowing
upon a downgrading of the Liquidity Provider's short-term unsecured debt rating
issued by either Rating Agency below the applicable Threshold Rating (as
provided for in Section 3.6(c) of the Intercreditor Agreement) unless a
Replacement Liquidity Facility to replace this Agreement shall have been
previously delivered to the Borrower in accordance with said Section 3.6(c), by
delivery to the Liquidity Provider of a written and completed Notice of
Borrowing in substantially the form of Annex III attached hereto, signed by a
Responsible Officer of the Borrower, in an amount equal to the Maximum Available
Commitment at such time, and shall be used to fund the Class B Cash Collateral
Account in accordance with said Section 3.6(c) and Section 3.6(f) of the
Intercreditor Agreement.
<PAGE>   12
                                                                               8

                  (d) A Final Advance shall be made in a single Borrowing upon
the receipt by the Borrower of a Termination Notice from the Liquidity Provider
pursuant to Section 6.01 hereof by delivery to the Liquidity Provider of a
written and completed Notice of Borrowing in substantially the form of Annex IV
attached hereto, signed by a Responsible Officer of the Borrower, in an amount
equal to the Maximum Available Commitment at such time, and shall be used to
fund the Class B Cash Collateral Account (in accordance with Section 3.6(i) of
the Intercreditor Agreement) and Section 3.6(f) of the Intercreditor Agreement.

                  (e) Each Borrowing shall be made on notice in writing (a
"Notice of Borrowing") in substantially the form required by Section 2.02(a),
2.02(b), 2.02(c) or 2.02(d), as the case may be, given by the Borrower to the
Liquidity Provider. If a Notice of Borrowing is delivered by the Borrower in
respect of any Borrowing no later than 1:00 p.m. (New York City time) on a
Business Day, upon satisfaction of the conditions precedent set forth in Section
4.02 with respect to a requested Borrowing, the Liquidity Provider shall make
available to the Borrower, in accordance with its payment instructions, the
amount of such Borrowing in U.S. dollars and immediately available funds, before
3:00 p.m. (New York City time) on such Business Day or on such later Business
Day specified in such Notice of Borrowing. If a Notice of Borrowing is delivered
by the Borrower in respect of any Borrowing after 1:00 p.m. (New York City time)
on a Business Day, upon satisfaction of the conditions precedent set forth in
Section 4.02 with respect to a requested Borrowing, the Liquidity Provider shall
make available to the Borrower, in accordance with its payment instructions, the
amount of such Borrowing in U.S. dollars and immediately available funds, before
12:00 Noon (New York City time) on the first Business Day next following the day
of receipt of such Notice of Borrowing or on such later Business Day specified
by the Borrower in such Notice of Borrowing. Payments of proceeds of a Borrowing
shall be made by wire transfer of immediately available funds to the Borrower in
accordance with such wire transfer instructions as the Borrower shall furnish
from time to time to the Liquidity Provider for such purpose. Each Notice of
Borrowing shall be irrevocable and binding on the Borrower.

                  (f) Upon the making of any Advance requested pursuant to a
Notice of Borrowing, in accordance with the Borrower's payment instructions, the
Liquidity Provider shall be fully discharged of its obligation hereunder with
respect to such Notice of Borrowing, and the Liquidity Provider shall not
thereafter be obligated to make any further Advances hereunder in respect of
such Notice of Borrowing to the Borrower or to any other Person. Following the
making of any Advance pursuant to Section 2.02(b), (c) or (d) hereof to fund the
Class B Cash Collateral Account, the Liquidity Provider shall have no interest
in or rights to the Class B Cash Collateral Account, such Advance or any other
amounts from time to time on deposit in the Class B Cash Collateral Account;
provided that the foregoing shall not affect or impair the obligations of the
Subordination Agent to make the distributions contemplated by Section 3.6(e) or
(f) of the Intercreditor Agreement. By paying to the Borrower proceeds of
Advances requested by the Borrower in accordance with the provisions of this
Agreement, the Liquidity Provider makes no representation as to, and assumes no
responsibility for, the correctness or sufficiency for any purpose of the amount
of the Advances so made and requested.

                  Section 2.03. Fees. The Borrower agrees to pay to the
Liquidity Provider the fees set forth in the Fee Letter.

                  Section 2.04. Adjustments or Termination of the Maximum
Commitment.
<PAGE>   13
                                                                               9

                  (a) Automatic Adjustments. Promptly following each date on
which the Required Amount is (1) reduced as a result of a reduction in the Pool
Balance of the Class B Certificates or otherwise, (2) increased as a result of
an increase in the Stated Interest Rate or (3) subsequent to such an increase
described in clause (2), reduced pursuant to the definition of "Stated Interest
Rate", the Maximum Commitment shall automatically be reduced or increased, as
the case may be, to an amount equal to the Required Amount (as calculated by the
Borrower). The Borrower shall give notice of any such automatic reduction or
increase, as the case may be, of the Maximum Commitment to the Liquidity
Provider within two Business Days thereof. The failure by the Borrower to
furnish any such notice shall not affect such automatic reduction or increase of
the Maximum Commitment.

                  (b) Termination. Upon the making of any Provider Advance or
Final Advance hereunder or the occurrence of the Termination Date, the
obligation of the Liquidity Provider to make further Advances hereunder shall
automatically and irrevocably terminate, and the Borrower shall not be entitled
to request any further Borrowing hereunder.

                  Section 2.05. Repayments of Interest Advances or the Final
Advance. Subject to Sections 2.06, 2.07 and 2.09 hereof, the Borrower hereby
agrees, without notice of an Advance or demand for repayment from the Liquidity
Provider (which notice and demand are hereby waived by the Borrower), to pay, or
to cause to be paid, to the Liquidity Provider on each date on which the
Liquidity Provider shall make an Interest Advance or the Final Advance, an
amount equal to (a) the amount of such Advance (any such Advance, until repaid,
is referred to herein as an "Unpaid Advance"), plus (b) interest on the amount
of each such Unpaid Advance as provided in Section 3.07 hereof; provided that if
(i) the Liquidity Provider shall make a Provider Advance at any time after
making one or more Interest Advances which shall not have been repaid in
accordance with this Section 2.05 or (ii) this Liquidity Facility shall become a
Downgraded Facility or Non-Extended Facility at any time when unreimbursed
Interest Advances have reduced the Maximum Available Commitment to zero, then
such Interest Advances shall cease to constitute Unpaid Advances and shall be
deemed to have been changed into an Applied Downgrade Advance or an Applied
Non-Extension Advance, as the case may be, for all purposes of this Agreement
(including, without limitation, for the purpose of determining when such
Interest Advance is required to be repaid to the Liquidity Provider in
accordance with Section 2.06 and for the purposes of Section 2.06(b)). The
Borrower and the Liquidity Provider agree that the repayment in full of each
Interest Advance and Final Advance on the date such Advance is made is intended
to be a contemporaneous exchange for new value given to the Borrower by the
Liquidity Provider.

                  Section 2.06. Repayments of Provider Advances. (a) Amounts
advanced hereunder in respect of a Provider Advance shall be deposited in the
Class B Cash Collateral Account, invested and withdrawn from the Class B Cash
Collateral Account as set forth in Sections 3.6(c), (d) and (f) of the
Intercreditor Agreement. The Borrower agrees to pay to the Liquidity Provider,
on each Regular Distribution Date, commencing on the first Regular Distribution
Date after the making of a Provider Advance, interest on the principal amount of
any such Provider Advance as provided in Section 3.07; provided, however, that
amounts in respect of a Provider Advance withdrawn from the Class B Cash
Collateral Account for the purpose of paying interest on the Class B
Certificates in accordance with Section 3.6(f) of the Intercreditor Agreement
(the amount of any such withdrawal being (y) in the case of a 
<PAGE>   14
                                                                              10

Downgrade Advance, an "Applied Downgrade Advance" and (z) in the case of a
Non-Extension Advance, an "Applied Non-Extension Advance" and, together with an
Applied Downgrade Advance, an "Applied Provider Advance") shall thereafter
(subject to Section 2.06(b)) be treated as an Interest Advance under this
Agreement for purposes of determining the Applicable Liquidity Rate for interest
payable thereon; provided further, however, that if, following the making of a
Provider Advance, the Liquidity Provider delivers a Termination Notice to the
Borrower pursuant to Section 6.01 hereof, such Provider Advance shall thereafter
be treated as a Final Advance under this Agreement for purposes of determining
the Applicable Liquidity Rate for interest payable thereon. Subject to Sections
2.07 and 2.09 hereof, immediately upon the withdrawal of any amounts from the
Class B Cash Collateral Account on account of a reduction in the Required
Amount, the Borrower shall repay to the Liquidity Provider a portion of the
Provider Advances in a principal amount equal to such reduction, plus interest
on the principal amount prepaid as provided in Section 3.07 hereof.

                  (b) At any time when an Applied Provider Advance (or any
portion thereof) is outstanding, upon the deposit in the Class B Cash Collateral
Account of any amount pursuant to clause "third" of Section 2.4(b) of the
Intercreditor Agreement, clause "third" of Section 3.2 of the Intercreditor
Agreement or clause "fourth" of Section 3.3 of the Intercreditor Agreement (any
such amount being a "Replenishment Amount") for the purpose of replenishing or
increasing the balance thereof up to the Required Amount at such time, (i) the
aggregate outstanding principal amount of all Applied Provider Advances (and of
Provider Advances treated as an Interest Advance for purposes of determining the
Applicable Liquidity Rate for interest payable thereon) shall be automatically
reduced by the amount of such Replenishment Amount and (ii) the aggregate
outstanding principal amount of all Unapplied Provider Advances shall be
automatically increased by the amount of such Replenishment Amount.

                  (c) Upon the provision of a Replacement Liquidity Facility in
replacement of this Agreement in accordance with Section 3.6(e) of the
Intercreditor Agreement, amounts remaining on deposit in the Class B Cash
Collateral Account after giving effect to any Applied Provider Advance on the
date of such replacement shall be reimbursed to the Liquidity Provider, but only
to the extent such amounts are necessary to repay in full to the Liquidity
Provider all amounts owing to it hereunder.

                  Section 2.07. Payments to the Liquidity Provider Under the
Intercreditor Agreement. In order to provide for payment or repayment to the
Liquidity Provider of any amounts hereunder, the Intercreditor Agreement
provides that amounts available and referred to in Articles II and III of the
Intercreditor Agreement, to the extent payable to the Liquidity Provider
pursuant to the terms of the Intercreditor Agreement (including, without
limitation, Section 3.6(f) of the Intercreditor Agreement), shall be paid to the
Liquidity Provider in accordance with the terms thereof. Amounts so paid to the
Liquidity Provider shall be applied by the Liquidity Provider to Liquidity
Obligations then due and payable in accordance with the Intercreditor Agreement
or, if not provided for in the Intercreditor Agreement, then in such manner as
the Liquidity Provider shall deem appropriate.

                  Section 2.08. Book Entries. The Liquidity Provider shall
maintain in accordance with its usual practice an account or accounts evidencing
the indebtedness of the Borrower resulting from Advances made from time to time
and the amounts of principal and interest payable hereunder and paid from time
to time in respect thereof; provided, however, that the
<PAGE>   15
                                                                              11

failure by the Liquidity Provider to maintain such account or accounts shall not
affect the obligations of the Borrower in respect of Advances.

                  Section 2.09. Payments from Available Funds Only. All payments
to be made by the Borrower under this Agreement shall be made only from the
amounts that constitute Scheduled Payments, Special Payments or payments under
Section 7.1 or 9.1, as the case may be, of the Participation Agreements and
Section 6 of the Note Purchase Agreement and only to the extent that the
Borrower shall have sufficient income or proceeds therefrom to enable the
Borrower to make payments in accordance with the terms hereof after giving
effect to the priority of payments provisions set forth in the Intercreditor
Agreement. The Liquidity Provider agrees that it will look solely to such
amounts to the extent available for distribution to it as provided in the
Intercreditor Agreement and this Agreement and that the Borrower, in its
individual capacity, is not personally liable to it for any amounts payable or
liability under this Agreement except as expressly provided in this Agreement,
the Intercreditor Agreement or any Participation Agreement. Amounts on deposit
in the Class B Cash Collateral Account shall be available to the Borrower to
make payments under this Agreement only to the extent and for the purposes
expressly contemplated in Section 3.6(f) of the Intercreditor Agreement.

                  Section 2.10. Extension of the Expiry Date; Non-Extension
Advance. No earlier than the 60th day and no later than the 40th day prior to
the then effective Expiry Date (unless such Expiry Date is on or after the date
that is 15 days after the Final Legal Distribution Date for the Class B
Certificates), the Borrower shall request that the Liquidity Provider extend the
Expiry Date for a period of 364 days after the then effective Expiry Date
(unless the obligations of the Liquidity Provider are earlier terminated in
accordance with the terms hereof). The Liquidity Provider shall advise the
Borrower, no earlier than 40 days and no later than 25 days prior to the then
effective Expiry Date, whether, in its sole discretion, it agrees to so extend
the Expiry Date. If the Liquidity Provider advises the Borrower on or before the
25th day prior to the Expiry Date then in effect that such Expiry Date shall not
be so extended, or fails to irrevocably and unconditionally advise the Borrower
on or before the 25th day prior to the Expiry Date then in effect that such
Expiry Date shall be so extended (and, in each case, if the Liquidity Provider
shall not have been replaced in accordance with Section 3.6(e) of the
Intercreditor Agreement), the Borrower shall be entitled on and after such 25th
day (but prior to the then effective Expiry Date) to request a Non-Extension
Advance in accordance with Section 2.02(b) hereof and Section 3.6(d) of the
Intercreditor Agreement.
<PAGE>   16
                                                                              12

                                   ARTICLE III

                           OBLIGATIONS OF THE BORROWER

                  Section 3.01. Increased Costs. The Borrower shall pay to the
Liquidity Provider from time to time such amounts as may be necessary to
compensate the Liquidity Provider for any increased costs incurred by the
Liquidity Provider which are reasonably attributable to its making or
maintaining any LIBOR Advances hereunder or its obligation to make any such
Advances hereunder, or any reduction in any amount receivable by the Liquidity
Provider under this Agreement or the Intercreditor Agreement in respect of any
such Advances or such obligation (such increases in costs and reductions in
amounts receivable being herein called "Additional Costs"), resulting from any
change after the date of this Agreement in U.S. federal, state, municipal, or
foreign laws or regulations (including Regulation D of the Board of Governors of
the Federal Reserve System applicable to banks generally), or the adoption or
making after the date of this Agreement of any interpretations, directives, or
requirements applying to a class of banks including the Liquidity Provider under
any U.S. federal, state, municipal, or any foreign laws or regulations (whether
or not having the force of law but of the type with which the Liquidity Provider
is accustomed to comply) by any court, central bank or monetary authority
charged with the interpretation or administration thereof in each case not
publicly announced on the date hereof (a "Regulatory Change"), which: (1)
changes the basis of taxation of any amounts payable to the Liquidity Provider
under this Agreement in respect of any such Advances (other than Excluded
Taxes); or (2) imposes or modifies any reserve, special deposit, compulsory loan
or similar requirements relating to any extensions of credit hereunder in
respect of LIBOR Advances (including any such Advances or any deposits referred
to in the definition of LIBOR Rate or related definitions), other than (i) costs
which arise as a result of the Liquidity Provider willfully contravening or
exceeding any operating limits or other restrictions imposed on it by any
authority; or (ii) if the increased costs would not have arisen but for any
assignment to another Liquidity Provider or an alteration in the lending office
of the Liquidity Provider. The Liquidity Provider agrees to use reasonable
efforts (consistent with applicable legal and regulatory restrictions) to change
the jurisdiction of its Lending Office if making such change would avoid the
need for, or reduce the amount of, any amount payable under this Section that
may thereafter accrue and would not, in the reasonable judgment of the Liquidity
Provider, be otherwise materially disadvantageous to the Liquidity Provider.

                  The Liquidity Provider will notify the Borrower of any event
occurring after the date of this Agreement that will entitle the Liquidity
Provider to compensation pursuant to this Section 3.01 as promptly as
practicable after it obtains knowledge thereof and determines to request such
compensation, which notice shall describe in reasonable detail the calculation
of the amounts owed under this Section; provided, that if the Liquidity Provider
fails to give such notice within 30 days after it obtains such knowledge, the
Liquidity Provider shall, with respect to any costs resulting from such event,
only be entitled to payment under this Section 3.01 for costs incurred from and
after the date 30 days prior to the date the Liquidity Provider does give such
notice. Determinations by the Liquidity Provider for purposes of this Section
3.01 of the effect of any Regulatory Change on its costs of making or
maintaining Advances or on amounts receivable by it in respect of Advances, and
of the additional amounts required to compensate the Liquidity Provider in
respect of any Additional Costs, shall be prima facie evidence of the amount
owed under this Section.
<PAGE>   17
                                                                              13

                  The Liquidity Provider shall not be entitled to compensation
under this Section 3.01 if (1) it shall not be also seeking compensation (if it
should be so entitled) under other comparable contractual provisions in its
other agreements, (2) if its claim under this Section 3.01 arises through
circumstances peculiar to the Liquidity Provider and which do not affect a
similarly organized commercial banking institution in the same jurisdiction
generally, or (3) the Liquidity Provider is not the initial liquidity provider
and America West did not consent to the transfer of this facility to the
Liquidity Provider, for the amount, if any, payable under this Section 3.01
resulting from events occurring prior to the date the Liquidity Provider
acquired its interests hereunder as shall exceed the amount payable under this
Section 3.01 that would have been due to the Liquidity Provider's transferor had
it continued to be the liquidity provider hereunder.

                  Section 3.02. Capital Adequacy. If (1) the adoption, after the
date hereof, of any applicable governmental law, rule or regulation regarding
capital adequacy and not publicly announced on the date hereof, (2) any change,
after the date hereof, in the interpretation or administration of any such law,
rule or regulation by any central bank or other governmental authority charged
with the interpretation or administration thereof and not publicly announced on
the date hereof or (3) compliance by the Liquidity Provider or any corporation
controlling the Liquidity Provider with any applicable guideline or request of
general applicability, issued after the date hereof and not publicly announced
on the date hereof, by any central bank or other governmental authority (whether
or not having the force of law but of the type with which the Liquidity Provider
is accustomed to comply) that constitutes a change of the nature described in
clause (2), has the effect of requiring an increase in the amount of capital
required to be maintained by the Liquidity Provider or any corporation
controlling the Liquidity Provider, and such increase is based upon the
Liquidity Provider's obligations hereunder and other similar obligations, the
Borrower shall pay to the Liquidity Provider from time to time such additional
amount or amounts as are necessary to compensate the Liquidity Provider for such
portion of such increase as shall be reasonably allocable to the Liquidity
Provider's obligations to the Borrower hereunder. The Liquidity Provider agrees
to use reasonable efforts (consistent with applicable legal and regulatory
restrictions) to change the jurisdiction of its Lending Office if making such
change would avoid the need for, or reduce the amount of, any amount payable
under this Section that may thereafter accrue and would not, in the reasonable
judgment of the Liquidity Provider, be otherwise materially disadvantageous to
the Liquidity Provider.

                  The Liquidity Provider will notify the Borrower of any event
occurring after the date of this Agreement that will entitle the Liquidity
Provider to compensation pursuant to this Section 3.02 as promptly as
practicable after it obtains knowledge thereof and determines to request such
compensation, which notice shall describe in reasonable detail the calculation
of the amounts owed under this Section; provided that if the Liquidity Provider
fails to give such notice within 30 days after it obtains such knowledge, the
Liquidity Provider shall, with respect of any costs resulting from such event,
only be entitled to payment under this Section 3.02 for costs incurred from and
after the date 30 days prior to the date the Liquidity Provider does give such
notice. Determinations by the Liquidity Provider for purposes of this Section
3.02 of the effect of any increase in the amount of capital required to be
maintained by the Liquidity Provider and of the amount allocable to the
Liquidity Provider's obligations to the Borrower hereunder shall be prima facie
evidence of the amounts owed under this Section.
<PAGE>   18
                                                                              14

                  The Liquidity Provider shall not be entitled to compensation
under this Section 3.02 if (1) it shall not be also seeking compensation (if it
should be so entitled) under other comparable contractual provisions in its
other agreements, (2) if its claim under this Section 3.02 arises through
circumstances peculiar to the Liquidity Provider and which do not affect a
similarly organized commercial banking institution in the same jurisdiction
generally, or (3) the Liquidity Provider is not the initial liquidity provider
and America West did not consent to the transfer of this facility to the
Liquidity Provider, for the amount, if any, payable under this Section 3.02
resulting from events occurring prior to the date the Liquidity Provider
acquired its interests hereunder as shall exceed the amount payable under this
Section 3.02 that would have been due to the Liquidity Provider's transferor had
it continued to be the liquidity provider hereunder.

                  Section 3.03. Payments Free of Deductions. (a) All payments
made by the Borrower under this Agreement shall be made free and clear of, and
without reduction for or on account of, any present or future stamp or other
taxes, levies, imposts, duties, deductions or withholdings, of a similar nature
other than Excluded Taxes (collectively, "Non-Excluded Taxes" and, individually,
a "Non-Excluded Tax"). If any Non-Excluded Taxes are required to be withheld
from any amounts payable to the Liquidity Provider under this Agreement, the
Liquidity Provider shall notify the Borrower and America West thereof and from
and after such notice, the amounts so payable to the Liquidity Provider shall be
increased to the extent necessary to yield to the Liquidity Provider (after
payment of all Non-Excluded Taxes) the amount it would have received had no such
deduction or withholding occurred. The Liquidity Provider agrees to use
reasonable efforts (consistent with its legal and regulatory restrictions) to
change the jurisdiction of its Lending Office if making such change would avoid
the need for, or reduce the amount of, any such additional amounts that may
thereafter accrue and shall otherwise take such reasonable steps as are open to
it to mitigate the effects of such circumstances provided that the Liquidity
Provider shall be under no obligation to take any such action if to do so would
have a material adverse effect on its business, operations or financial
condition or result in its rights, interests or position under this Agreement
being prejudiced or involved in any unlawful activity. From time to time upon
the reasonable request of the Borrower, the Liquidity Provider agrees to provide
to the Borrower two original Internal Revenue Service Form 1001 or 4224, as
appropriate, or any successor or other form prescribed by the Internal Revenue
Service, certifying that the Liquidity Provider is exempt from or entitled to a
reduced rate of United States withholding tax on payments pursuant to this
Agreement.

                  Section 3.04. Payments. The Borrower shall make or cause to be
made each payment to the Liquidity Provider under this Agreement so as to cause
the same to be received by the Liquidity Provider not later than 1:00 P.M. (New
York City time) on the day when due. The Borrower shall make all such payments
in lawful money of the United States of America, to the Liquidity Provider in
immediately available funds, by wire transfer to ABN AMRO Bank N.V., New York,
New York, ABA # 026009580 for account of ABN AMRO Bank N.V., Chicago Branch CPU,
Account No. 650-001-1789-41, Account Reference: America West Airlines Liquidity
Facility 1998-1B.

                  Section 3.05. Computations. All computations of interest based
on the Base Rate shall be made on the basis of a year of 365 or 366 days, as the
case may be, and all computations of interest based on the LIBOR Rate shall be
made on the basis of a year of 360 days, in each
<PAGE>   19
                                                                              15

case for the actual number of days (including the first day but excluding the
last day) occurring in the period for which such interest is payable.

                  Section 3.06. Payment on Non-Business Days. Whenever any
payment to be made hereunder shall be stated to be due on a day other than a
Business Day, such payment shall be made on the next succeeding Business Day and
no additional interest shall be due as a result (and if so made, shall be deemed
to have been made when due). If any payment in respect of interest on an Advance
is so deferred to the next succeeding Business Day, such deferral shall not
delay the commencement of the next Interest Period for such Advance (if such
Advance is a LIBOR Advance) or reduce the number of days for which interest will
be payable on such Advance on the next interest payment date for such Advance.

                  Section 3.07. Interest. (a) Subject to Section 2.09, the
Borrower shall pay, or shall cause to be paid, without duplication, interest on
(i) the unpaid principal amount of each Advance from and including the date of
such Advance (or, in the case of an Applied Provider Advance, from and including
the date on which the amount thereof was withdrawn from the Class B Cash
Collateral Account to pay interest on the Class B Certificates) to but excluding
the date such principal amount shall be paid in full (or, in the case of an
Applied Provider Advance, the date on which the Class B Cash Collateral Account
is fully replenished in respect of such Advance) and (ii) any other amount due
hereunder (whether fees, commissions, expenses or other amounts or, to the
extent permitted by law, installments of interest on Advances or any such other
amount) which is not paid when due (whether at stated maturity, by acceleration
or otherwise) from and including the due date thereof to but excluding the date
such amount is paid in full, in each such case, at a fluctuating interest rate
per annum for each day equal to the Applicable Liquidity Rate for such Advance
or such other amount as in effect for such day, but in no event at a rate per
annum greater than the maximum rate permitted by applicable law; provided,
however, that, if at any time the otherwise applicable interest rate as set
forth in this Section 3.07 shall exceed the maximum rate permitted by applicable
law, then any subsequent reduction in such interest rate will not reduce the
rate of interest payable pursuant to this Section 3.07 below the maximum rate
permitted by applicable law until the total amount of interest accrued equals
the amount of interest that would have accrued if such otherwise applicable
interest rate as set forth in this Section 3.07 had at all times been in effect.

                  (b) Each Advance will be either a Base Rate Advance or a LIBOR
Advance as provided in this Section. Each such Advance will be a Base Rate
Advance for the period from the date of its borrowing to (but excluding) the
third Business Day following the Liquidity Provider's receipt of the Notice of
Borrowing for such Advance. Thereafter, such Advance shall be a LIBOR Advance.

                  (c) Each LIBOR Advance shall bear interest during each
Interest Period at a rate per annum equal to the LIBOR Rate for such Interest
Period plus the Applicable Margin for such LIBOR Advance, payable in arrears on
the last day of such Interest Period and, in the event of the payment of
principal of such LIBOR Advance on a day other than such last day, on the date
of such payment (to the extent of interest accrued on the amount of principal
repaid).

                  (d) Each Base Rate Advance shall bear interest at a rate per
annum equal to the Base Rate plus the Applicable Margin for such Base Rate
Advance, payable in arrears on each Regular Distribution Date and, in the event
of the payment of principal of such Base Rate
<PAGE>   20
                                                                              16

Advance on a day other than a Regular Distribution Date, on the date of such
payment (to the extent of interest accrued on the amount of principal repaid).

                  (e) Each amount not paid when due hereunder (whether fees,
commissions, expenses or other amounts or, to the extent permitted by applicable
law, installments of interest on Advances but excluding Advances) shall bear
interest at a rate per annum equal to the Base Rate plus 2% until paid.

                  (f) Each change in the Base Rate shall become effective
immediately. The rates of interest specified in this Section 3.07 with respect
to any Advance or other amount shall be referred to as the "Applicable Liquidity
Rate".

                  Section 3.08. Replacement of Subordination Agent. From time to
time and subject to the successor Subordination Agent's meeting the eligibility
requirements set forth in Section 6.9 of the Intercreditor Agreement applicable
to the Subordination Agent, upon the effective date and time specified in a
written and completed Notice of Replacement Subordination Agent in substantially
the form of Annex VI attached hereto (a "Notice of Replacement Subordination
Agent") delivered to the Liquidity Provider by the then Subordination Agent, the
successor Subordination Agent designated therein shall be substituted for as the
Subordination Agent for all purposes hereunder.

                  Section 3.09. Funding Loss Indemnification. The Borrower shall
pay to the Liquidity Provider, upon the request of the Liquidity Provider, such
amount or amounts as shall be sufficient (in the reasonable opinion of the
Liquidity Provider) to compensate it for any loss incurred by it by reason of
the liquidation or redeployment of deposits or other funds acquired by the
Liquidity Provider to fund or maintain any LIBOR Advance (but excluding loss of
anticipated profits) incurred as a result of:

                  (1) Any repayment of a LIBOR Advance on a date other than the
         last day of the Interest Period for such Advance; or

                  (2) Any failure by the Borrower to borrow a LIBOR Advance on
         the date for borrowing specified in the relevant notice under Section
         2.02.

                  Section 3.10. Illegality. Notwithstanding any other provision
in this Agreement, if any change in any applicable law, rule or regulation not
publicly announced on the date hereof shall make it unlawful or impossible for
the Liquidity Provider (or its Lending Office) to maintain or fund its LIBOR
Advances without breaking such law, then upon notice to the Borrower by the
Liquidity Provider, the outstanding principal amount of the LIBOR Advances shall
be converted to Base Rate Advances to the extent necessary to cure such
illegality (a) immediately upon demand of the Liquidity Provider, if such change
or compliance with such request, in the judgment of the Liquidity Provider,
requires immediate repayment; or (b) at the expiration of the last Interest
Period to expire before the effective date of any such change or request. The
Liquidity Provider agrees to use reasonable efforts (consistent with applicable
legal and regulatory restrictions) to change the jurisdiction of its Lending
Office if making such change would avoid or cure the aforesaid illegality.
<PAGE>   21
                                                                              17

                                   ARTICLE IV

                              CONDITIONS PRECEDENT

                  Section 4.01. Conditions Precedent to Effectiveness of Section
2.01. Section 2.01 of this Agreement shall become effective on and as of the
first date (the "Effective Date") on which the following conditions precedent
have been satisfied or waived:

                  (a) The Liquidity Provider shall have received on or before
         the Closing Date each of the following, and in the case of each
         document delivered pursuant to paragraphs (i), (ii) and (iii), each in
         form and substance satisfactory to the Liquidity Provider:

                           (i) This Agreement duly executed on behalf of the
                  Borrower;

                           (ii) The Intercreditor Agreement duly executed on
                  behalf of each of the parties thereto;

                           (iii) Fully executed copies of each of the Operative
                  Agreements executed and delivered on or before the Closing
                  Date (other than this Agreement and the Intercreditor
                  Agreement);

                           (iv) A copy of the Offering Memorandum and specimen
                  copies of the Class B Certificates;

                           (v) An executed copy of each document, instrument,
                  certificate and opinion delivered on or before the Closing
                  Date pursuant to the Class B Trust Agreement, the
                  Intercreditor Agreement and the other Operative Agreements (in
                  the case of each such opinion, other than the opinion of
                  counsel for the Initial Purchasers, either addressed to the
                  Liquidity Provider or accompanied by a letter from the counsel
                  rendering such opinion to the effect that the Liquidity
                  Provider is entitled to rely on such opinion as of its date as
                  if it were addressed to the Liquidity Provider);

                           (vi) Evidence that there shall have been made and
                  shall be in full force and effect, all filings, recordings
                  and/or registrations, and there shall have been given or taken
                  any notice or other similar action as are necessary or in
                  order to establish, perfect, protect and preserve the right,
                  title and interest of the Liquidity Provider created by the
                  Operative Agreements executed and delivered on or prior to the
                  Closing Date;

                           (vii) An agreement from America West, pursuant to
                  which America West agrees to provide copies of quarterly
                  financial statements and audited annual financial statements
                  to the Liquidity Provider (which obligations may be satisfied
                  by the furnishing of America West's Form 10Q and 10K), in each
                  case, only to the extent that America West is obligated to
                  provide such information pursuant to Section 8.2.1 of the
                  Leases (related to Leased Aircraft) or the corresponding
                  section of the Indentures (related to Owned Aircraft) to the
                  parties thereto; and
<PAGE>   22
                                                                              18

                           (viii) Such other documents, instruments, opinions
                  and approvals pertaining to the transactions contemplated
                  hereby or by the other Operative Agreements as the Liquidity
                  Provider shall have reasonably requested.

                  (b) The following statement shall be true on and as of the
         Effective Date: no event has occurred and is continuing, or would
         result from the entering into of this Agreement or the making of any
         Advance, which constitutes a Liquidity Event of Default.

                  (c) The Liquidity Provider shall have received payment in full
         of all fees and other sums required to be paid to or for account of the
         Liquidity Provider on or prior to the Effective Date.

                  (d) All conditions precedent to the issuance of the
         Certificates under the Trust Agreements shall have been satisfied or
         waived, all conditions precedent to the effectiveness of the other
         Liquidity Facilities shall have been satisfied or waived, and all
         conditions precedent to the purchase of the Certificates by the Initial
         Purchasers under the Purchase Agreement shall have been satisfied
         (unless any of such conditions precedent shall have been waived by the
         Initial Purchasers).

                  (e) The Borrower shall have received a certificate, dated the
         date hereof, signed by a duly authorized representative of the
         Liquidity Provider, certifying that all conditions precedent to the
         effectiveness of Section 2.01 have been satisfied or waived.

                  Section 4.02. Conditions Precedent to Borrowing. The
obligation of the Liquidity Provider to make an Advance on the occasion of each
Borrowing shall be subject to the conditions precedent that the Effective Date
shall have occurred and, prior to the date of such Borrowing, the Borrower shall
have delivered a Notice of Borrowing which conforms to the terms and conditions
of this Agreement and has been completed as may be required by the relevant form
of the Notice of Borrowing for the type of Advances requested.



                                    ARTICLE V

                                    COVENANTS

                  Section 5.01. Affirmative Covenants of the Borrower. So long
as any Advance shall remain unpaid or the Liquidity Provider shall have any
Maximum Commitment hereunder or the Borrower shall have any obligation to pay
any amount to the Liquidity Provider hereunder, the Borrower will, unless the
Liquidity Provider shall otherwise consent in writing:

                  (a) Performance of This and Other Agreements. Punctually pay
         or cause to be paid all amounts payable by it under this Agreement and
         the other Operative Agreements and observe and perform in all material
         respects the conditions, covenants and requirements applicable to it
         contained in this Agreement and the other Operative Agreements.
<PAGE>   23
                                                                              19

                  (b) Reporting Requirements. Furnish to the Liquidity Provider
         with reasonable promptness, such other information and data with
         respect to the transactions contemplated by the Operative Agreements as
         from time to time may be reasonably requested by the Liquidity
         Provider; and permit the Liquidity Provider, upon reasonable notice, to
         inspect the Borrower's books and records with respect to such
         transactions and to meet with officers and employees of the Borrower to
         discuss such transactions.

                  (c) Certain Operative Agreements. Furnish to the Liquidity
         Provider with reasonable promptness, such Operative Agreements entered
         into after the date hereof as from time to time may be reasonably
         requested by the Liquidity Provider.

                  Section 5.02. Negative Covenants of the Borrower. So long as
any Advance shall remain unpaid or the Liquidity Provider shall have any Maximum
Commitment hereunder or the Borrower shall have any obligation to pay any amount
to the Liquidity Provider hereunder, the Borrower will not appoint or permit or
suffer to be appointed any successor Borrower without the prior written consent
of the Liquidity Provider, which consent shall not be unreasonably withheld or
delayed.


                                   ARTICLE VI

                           LIQUIDITY EVENTS OF DEFAULT

                  Section 6.01. Liquidity Events of Default. If (a) any
Liquidity Event of Default has occurred and is continuing and (b) there is a
Performing Note Deficiency, the Liquidity Provider may, in its discretion,
deliver to the Borrower a Termination Notice, the effect of which shall be to
cause (i) the obligation of the Liquidity Provider to make Advances hereunder to
expire on the fifth Business Day after the date on which such Termination Notice
is received by the Borrower, (ii) the Borrower to promptly request, and the
Liquidity Provider to promptly make, a Final Advance in accordance with Section
2.02(d) hereof and Section 3.6(i) of the Intercreditor Agreement, (iii) all
other outstanding Advances to be automatically converted into Final Advances for
purposes of determining the Applicable Liquidity Rate for interest payable
thereon, and (iv) subject to Sections 2.07 and 2.09 hereof, all Advances
(including, without limitation, any Provider Advance and Applied Provider
Advance), any accrued interest thereon and any other amounts outstanding
hereunder to become immediately due and payable to the Liquidity Provider.


                                   ARTICLE VII

                                  MISCELLANEOUS

                  Section 7.01. Amendments, Etc. No amendment or waiver of any
provision of this Agreement, nor consent to any departure by the Borrower
therefrom, shall in any event be effective unless the same shall be in writing
and signed by the Liquidity Provider, and, in the case of an amendment or of a
waiver by the Borrower, the Borrower, and then such waiver or consent shall be
effective only in the specific instance and for the specific purpose for which
given.
<PAGE>   24
                                                                              20

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

                  Borrower:

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

                  Attention: Corporate Trust Administration
                  Telephone: 302-651-1000
                  Telecopy: 302-651-8882

                  Liquidity Provider:

                  ABN AMRO BANK N.V.
                  135 South LaSalle Street - Suite 660
                  Chicago, Illinois 60603

                  Attention:  Vice President - Aerospace
                  Telephone:  (312) 904-2900
                  Telecopy:  (312) 606-8428

                  with a copy to:

                  ABN AMRO BANK N.V.
                  135 South LaSalle Street - Suite 625
                  Chicago, Illinois 60603

                  Attention:  Loan Administration
                  Telephone:  (312) 904-2961
                  Telecopy:  (312) 904-1288

or, as to each of the foregoing, at such other address as shall be designated by
such Person in a written notice to the others. All such notices and
communications shall be effective when received unless received outside of
business hours, in which case on the next open of business on a Business Day. A
copy of all notices delivered hereunder to either party shall in addition be
delivered to each of the parties to the Participation Agreements at their
respective addresses set forth therein.

                  Section 7.03. No Waiver; Remedies. No failure on the part of
the Liquidity Provider to exercise, and no delay in exercising, any right under
this Agreement shall operate as a waiver thereof; nor shall any single or
partial exercise of any right under this Agreement preclude any other or further
exercise thereof or the exercise of any other right. The remedies herein
provided are cumulative and not exclusive of any remedies provided by law.
<PAGE>   25
                                                                              21

                  Section 7.04. Further Assurances. The Borrower agrees to do
such further acts and things and to execute and deliver to the Liquidity
Provider such additional assignments, agreements, powers and instruments as the
Liquidity Provider may reasonably require or deem advisable to carry into effect
the purposes of this Agreement and the other Operative Agreements or to better
assure and confirm unto the Liquidity Provider its rights, powers and remedies
hereunder and under the other Operative Agreements.

                  Section 7.05. Indemnification; Survival of Certain Provisions.
The Liquidity Provider shall be indemnified hereunder to the extent and in the
manner described in Section 7.1 or 9.1, as the case may be, of the Participation
Agreements. The indemnities contained in Section 7.1 or 9.1, as the case may be,
of the Participation Agreements, and the provisions of Sections 3.01, 3.02,
3.03, 3.09, 7.05 and 7.07 hereof, shall survive the termination of this
Agreement.

                  Section 7.06. Liability of the Liquidity Provider. (a) Neither
the Liquidity Provider nor any of its officers, employees, directors or
affiliates shall be liable or responsible for: (i) the use which may be made of
the Advances or any acts or omissions of the Borrower or any beneficiary or
transferee in connection therewith; or (ii) the validity, sufficiency or
genuineness of documents, or of any endorsement thereon, even if such documents
should prove to be in any or all respects invalid, insufficient, fraudulent or
forged except as executed by the Liquidity Provider; provided, however, that the
Borrower shall have a claim against the Liquidity Provider, and the Liquidity
Provider shall be liable to the Borrower, to the extent of any damages suffered
by the Borrower which were the result of (A) the Liquidity Provider's willful
misconduct or negligence in determining whether documents presented hereunder
comply with the terms hereof, or (B) any breach by the Liquidity Provider of any
of the terms of this Agreement, including, but not limited to, the Liquidity
Provider's failure to make lawful payment hereunder after the delivery to it by
the Borrower of a Notice of Borrowing strictly complying with the terms and
conditions hereof.

                  (b) Neither the Liquidity Provider nor any of its officers,
employees, directors or affiliates shall be liable or responsible in any respect
for (i) any error, omission, interruption or delay in transmission, dispatch or
delivery of any message or advice, however transmitted, in connection with this
Agreement or any Notice of Borrowing delivered hereunder, or (ii) any action,
inaction or omission which may be taken by it in good faith, absent willful
misconduct or negligence (in which event the extent of the Liquidity Provider's
potential liability to the Borrower shall be limited as set forth in the
immediately preceding paragraph), in connection with this Agreement or any
Notice of Borrowing.

                  Section 7.07. Costs, Expenses and Taxes. The Borrower agrees
to pay, or cause to be paid (A) on the Effective Date and on such later date or
dates on which the Liquidity Provider shall make demand, all reasonable
out-of-pocket costs and expenses (including, without limitation, the reasonable
fees and expenses of outside counsel for the Liquidity Provider) of the
Liquidity Provider in connection with the preparation, negotiation, execution,
delivery, filing and recording of this Agreement, any other Operative Agreement
and any other documents which may be delivered in connection with this Agreement
and (B) on demand, all reasonable costs and expenses (including reasonable
counsel fees and expenses) of the Liquidity Provider in connection with (i) the
enforcement of this Agreement or any other Operative Agreement, (ii) the
modification or amendment of, or supplement to, this Agreement or any other
Operative
<PAGE>   26
                                                                              22

Agreement or such other documents which may be delivered in connection herewith
or therewith (whether or not the same shall become effective) other than
amendments requested by the Liquidity Provider or a transfer made by the
Liquidity Provider either voluntarily or as a result of the mitigation
provisions of Article 3 or a Non-Extension Drawing or a Downgrade Drawing or
(iii) any action or proceeding relating to any order, injunction, or other
process or decree restraining or seeking to restrain the Liquidity Provider from
paying any amount under this Agreement, the Intercreditor Agreement or any other
Operative Agreement or otherwise affecting the application of funds in the Class
B Cash Collateral Accounts. In addition, the Borrower shall pay any and all
recording, stamp and other similar taxes and fees payable or determined to be
payable in connection with the execution, delivery, filing and recording of this
Agreement, any other Operative Agreement and such other documents, other than
amendments requested by the Liquidity Provider or a transfer made by the
Liquidity Provider either voluntarily or as a result of the mitigation
provisions of Article 3 or a Non-Extension Drawing or a Downgrade Drawing, and
agrees to save the Liquidity Provider harmless from and against any and all
liabilities with respect to or resulting from any delay in paying or omission to
pay such taxes or fees.

                  Section 7.08. Binding Effect; Participations. (a) This
Agreement shall be binding upon and inure to the benefit of the Borrower and the
Liquidity Provider and their respective successors and assigns, except that
neither the Liquidity Provider (except as otherwise provided in this Section
7.08) nor (except as contemplated by Section 3.08) the Borrower shall have the
right to assign its rights or obligations hereunder or any interest herein
without the prior written consent of the other party, subject to the
requirements of Section 7.08(b). The Liquidity Provider may grant participations
herein or in any of its rights hereunder (including, without limitation, funded
participations and participations in rights to receive interest payments
hereunder) and under the other Operative Agreements to such Persons as the
Liquidity Provider may in its sole discretion select, subject to the
requirements of Section 7.08(b). No such participation by the Liquidity
Provider, however, will relieve the Liquidity Provider of its obligations
hereunder. In connection with any participation or any proposed participation,
the Liquidity Provider may disclose to the participant or the proposed
participant any information that the Borrower is required to deliver or to
disclose to the Liquidity Provider pursuant to this Agreement. The Borrower
acknowledges and agrees that the Liquidity Provider's source of funds may derive
in part from its participants (other than America West). Accordingly, references
in this Agreement and the other Operative Agreements to determinations, reserve
and capital adequacy requirements, increased costs, reduced receipts, additional
amounts due pursuant to Section 3.03 and the like as they pertain to the
Liquidity Provider shall be deemed also to include those of each of its
participants (subject, in each case, to the maximum amount that would have been
incurred by or attributable to the Liquidity Provider directly if the Liquidity
Provider, rather than the participant, had held the interest participated).

                  (b) If, pursuant to subsection (a) above, the Liquidity
Provider sells any participation in this Agreement to any bank or other entity
(each, a "Transferee"), then, concurrently with the effectiveness of such
participation, the Transferee shall (i) represent to the Liquidity Provider (for
the benefit of the Liquidity Provider and the Borrower) either (A) that it is
incorporated under the laws of the United States or a state thereof or (B) that
under applicable law and treaties, no taxes will be required to be withheld with
respect to any payments to be made to such Transferee in respect of this
Agreement, (ii) furnish to the Liquidity Provider and the Borrower either (x) a
statement that it is incorporated under the laws of the United States or a
<PAGE>   27
                                                                              23

state thereof or (y) if it is not so incorporated, two copies of a properly
completed United States Internal Revenue Service Form 4224 or Form 1001, as
appropriate, or other applicable form, certificate or document prescribed by the
Internal Revenue Service certifying, in each case, such Transferee's entitlement
to a complete exemption from United States federal withholding tax in respect to
any and all payments to be made hereunder, and (iii) agree (for the benefit of
the Liquidity Provider and the Borrower) to provide the Liquidity Provider and
the Borrower a new Form 4224 or Form 1001, as appropriate, (A) on or before the
date that any such form expires or becomes obsolete or (B) after the occurrence
of any event requiring a change in the most recent form previously delivered by
it and prior to the immediately following due date of any payment by the
Borrower hereunder, certifying in the case of a Form 1001 or Form 4224 that such
Transferee is entitled to a complete exemption from United States federal
withholding tax on payments under this Agreement. Unless the Borrower has
received forms or other documents reasonably satisfactory to it (and required by
applicable law) indicating that payments hereunder are not subject to United
States federal withholding tax, the Borrower will withhold taxes as required by
law from such payments at the applicable statutory rate.

                  (c) Notwithstanding the other provisions of this Section 7.08,
the Liquidity Provider may assign and pledge all or any portion of the Advances
owing to it to any Federal Reserve Bank or the United States Treasury as
collateral security pursuant to Regulation A of the Board of Governors of the
Federal Reserve System and any Operating Circular issued by such Federal Reserve
Bank, provided that any payment in respect of such assigned Advances made by the
Borrower to the Liquidity Provider in accordance with the terms of this
Agreement shall satisfy the Borrower's obligations hereunder in respect of such
assigned Advance to the extent of such payment. No such assignment shall release
the Liquidity Provider from its obligations hereunder.

                  Section 7.09. Severability. Any provision of this Agreement
which is prohibited, unenforceable or not authorized in any jurisdiction shall,
as to such jurisdiction, be ineffective to the extent of such prohibition,
unenforceability or non-authorization without invalidating the remaining
provisions hereof or affecting the validity, enforceability or legality of such
provision in any other jurisdiction.

                  Section 7.10. GOVERNING LAW. THIS AGREEMENT SHALL BE GOVERNED
BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.

                  Section 7.11. Submission to Jurisdiction; Waiver of Jury
Trial; Waiver of Immunity. (a) Each of the parties hereto hereby irrevocably and
unconditionally:

                  (i) submits for itself and its property in any legal action or
         proceeding relating to this Agreement or any other Operative Agreement,
         or for recognition and enforcement of any judgment in respect hereof or
         thereof, to the nonexclusive general jurisdiction of the courts of the
         State of New York, the courts of the United States of America for the
         Southern District of New York, and the appellate courts from any
         thereof;

                  (ii) consents that any such action or proceeding may be
         brought in such courts, and waives any objection that it may now or
         hereafter have to the venue of any
<PAGE>   28
                                                                              24

         such action or proceeding in any such court or that such action or
         proceeding was brought in an inconvenient court and agrees not to plead
         or claim the same;

                  (iii) agrees that service of process in any such action or
         proceeding may be effected by mailing a copy thereof by registered or
         certified mail (or any substantially similar form and mail), postage
         prepaid, to each party hereto at its address set forth in Section 7.02
         hereof, or at such other address of which the Liquidity Provider shall
         have been notified pursuant thereto; and

                  (iv) agrees that nothing herein shall affect the right to
         effect service of process in any other manner permitted by law or shall
         limit the right to sue in any other jurisdiction.

                  (b) THE BORROWER AND THE LIQUIDITY PROVIDER EACH HEREBY AGREE
TO WAIVE THEIR RESPECTIVE RIGHTS TO A JURY TRIAL OF ANY CLAIM OR CAUSE OF ACTION
BASED UPON OR ARISING OUT OF THIS AGREEMENT OR ANY DEALINGS BETWEEN THEM
RELATING TO THE SUBJECT MATTER OF THIS AGREEMENT AND THE RELATIONSHIP THAT IS
BEING ESTABLISHED, including, without limitation, contract claims, tort claims,
breach of duty claims and all other common law and statutory claims. The
Borrower and the Liquidity Provider each warrant and represent that it has
reviewed this waiver with its legal counsel, and that it knowingly and
voluntarily waives its jury trial rights following consultation with such legal
counsel. THIS WAIVER IS IRREVOCABLE, AND CANNOT BE MODIFIED EITHER ORALLY OR IN
WRITING, AND THIS WAIVER SHALL APPLY TO ANY SUBSEQUENT AMENDMENTS, RENEWALS,
SUPPLEMENTS OR MODIFICATIONS TO THIS AGREEMENT.

                  (c) The Liquidity Provider hereby waives any immunity it may
have from the jurisdiction of the courts of the United States or of any State
and waives any immunity any of its properties located in the United States may
have from attachment or execution upon a judgment entered by any such court
under the United States Foreign Sovereign Immunities Act of 1976 or any similar
successor legislation.

                  Section 7.12. Execution in Counterparts. This Agreement may be
executed in any number of counterparts and by different parties hereto on
separate counterparts, each of which counterparts, when so executed and
delivered, shall be deemed to be an original and all of which counterparts,
taken together, shall constitute but one and the same Agreement.

                  Section 7.13. Entirety. This Agreement, the Intercreditor
Agreement and the other Operative Agreements to which the Liquidity Provider is
a party constitute the entire agreement of the parties hereto with respect to
the subject matter hereof and supersedes all prior understandings and agreements
of such parties.

                  Section 7.14. Headings. Section headings in this Agreement are
included herein for convenience of reference only and shall not constitute a
part of this Agreement for any other purpose.
<PAGE>   29
                                                                              25

                  Section 7.15. Transfer. The Liquidity Provider hereby
acknowledges and consents to the Transfer contemplated by the Assignment and
Assumption Agreement.

                  Section 7.16. LIQUIDITY PROVIDER'S OBLIGATION TO MAKE
ADVANCES. EXCEPT AS EXPRESSLY SET FORTH IN THIS AGREEMENT, THE OBLIGATIONS OF
THE LIQUIDITY PROVIDER TO MAKE ADVANCES HEREUNDER, AND THE BORROWER'S RIGHTS TO
DELIVER NOTICES OF BORROWING REQUESTING THE MAKING OF ADVANCES HEREUNDER, SHALL
BE UNCONDITIONAL AND IRREVOCABLE, AND SHALL BE PAID OR PERFORMED, IN EACH CASE
STRICTLY IN ACCORDANCE WITH THE TERMS OF THIS AGREEMENT.
<PAGE>   30
                  IN WITNESS WHEREOF, the parties have caused this Agreement to
be duly executed and delivered by their respective officers thereunto duly
authorized as of the date first set forth above.

                            WILMINGTON TRUST COMPANY,
                                   not in its individual capacity but solely as
                                   Subordination Agent, as agent and trustee for
                                   the Class B Trust, as Borrower



                                    By:  /s/ Jill K. Morrison
                                       ------------------------------------
                                       Name:  Jill K. Morrison
                                       Title: Administrative Account Manager


                                    ABN AMRO BANK N.V., Chicago Branch
                                    as Liquidity Provider



                                    By:  /s/ Claudia C. Heldring
                                       ------------------------------------
                                       Name:  Claudia C. Heldring
                                       Title: Vice President



                                    By:  /s/ Carla S. Waggoner
                                       ------------------------------------
                                       Name:  Carla S. Waggoner
                                       Title: Assistant Vice President
<PAGE>   31
                                                                      Annex I to
                                                      Revolving Credit Agreement


                      INTEREST ADVANCE NOTICE OF BORROWING

                  The undersigned, a duly authorized signatory of the
undersigned borrower (the "Borrower"), hereby certifies to ABN AMRO BANK, N.V.,
Chicago Branch (the "Liquidity Provider"), with reference to the Revolving
Credit Agreement (1998-1B) dated as of October 6, 1998, between the Borrower and
the Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and
not otherwise defined herein being used herein as therein defined or
referenced), that:

                  (1) The Borrower is the Subordination Agent under the
         Intercreditor Agreement.

                  (2) The Borrower is delivering this Notice of Borrowing for
         the making of an Interest Advance by the Liquidity Provider to be used,
         subject to clause (3)(v) below, for the payment of interest on the
         Class B Certificates which was payable on ____________, ____ (the
         "Distribution Date") in accordance with the terms and provisions of the
         Class B Trust Agreement and the Class B Certificates, which Advance is
         requested to be made on the date hereof.

                  (3) The amount of the Interest Advance requested hereby (i) is
         $_______________.__, to be applied in respect of the payment of the
         interest which was due and payable on the Class B Certificates on the
         Distribution Date, (ii) does not include any amount with respect to the
         payment of principal of, or premium on, the Class A Certificates, the
         Class B Certificates or the Class C Certificates, or interest on the
         Class A Certificates or the Class C Certificates, (iii) was computed in
         accordance with the provisions of the Class B Certificates, the Class B
         Trust Agreement and the Intercreditor Agreement (a copy of which
         computation is attached hereto as Schedule I), (iv) does not exceed the
         Maximum Available Commitment on the date hereof, (v) does not include
         any amount of interest which was due and payable on the Class B
         Certificates on such Distribution Date but which remains unpaid due to
         the failure of the Depositary to pay any amount of accrued interest on
         the Deposits on such Distribution Date and (vi) has not been and is not
         the subject of a prior or contemporaneous Notice of Borrowing.

                  (4) Upon receipt by or on behalf of the Borrower of the amount
         requested hereby, (a) the Borrower will apply the same in accordance
         with the terms of Section 3.6(b) of the Intercreditor Agreement, (b) no
         portion of such amount shall be applied by the Borrower for any other
         purpose and (c) no portion of such amount until so applied shall be
         commingled with other funds held by the Borrower.

                  The Borrower hereby acknowledges that, pursuant to the
Liquidity Agreement, the making of the Interest Advance as requested by this
Notice of Borrowing shall automatically reduce, subject to reinstatement in
accordance with the terms of the Liquidity Agreement, the Maximum Available
Commitment by an amount equal to the amount of the Interest Advance

                                      I-1
<PAGE>   32
requested to be made hereby as set forth in clause (i) of paragraph (3) of this
Certificate and such reduction shall automatically result in corresponding
reductions in the amounts available to be borrowed pursuant to a subsequent
Advance.

                  IN WITNESS WHEREOF, the Borrower has executed and delivered
this Notice of Borrowing as of the ____ day of _________, ____.


                            WILMINGTON TRUST COMPANY,
                                   not in its individual capacity but solely as
                                   Subordination Agent, as Borrower


                                            By:_________________________________
                                                 Name:
                                                 Title:

                                      I-2
<PAGE>   33
               SCHEDULE I TO INTEREST ADVANCE NOTICE OF BORROWING

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

                                      I-3
<PAGE>   34
                                                                     Annex II to
                                                      Revolving Credit Agreement

                    NON-EXTENSION ADVANCE NOTICE OF BORROWING

                  The undersigned, a duly authorized signatory of the
undersigned subordination agent (the "Borrower"), hereby certifies to ABN AMRO
BANK N.V., Chicago Branch (the "Liquidity Provider"), with reference to the
Revolving Credit Agreement (1998-1B) dated as of October 6, 1998, between the
Borrower and the Liquidity Provider (the "Liquidity Agreement"; the terms
defined therein and not otherwise defined herein being used herein as therein
defined or referenced), that:

                  (1) The Borrower is the Subordination Agent under the
         Intercreditor Agreement.

                  (2) The Borrower is delivering this Notice of Borrowing for
         the making of the Non-Extension Advance by the Liquidity Provider to be
         used for the funding of the Class B Cash Collateral Account in
         accordance with Section 3.6(d) of the Intercreditor Agreement, which
         Advance is requested to be made on __________, ____.

                  (3) The amount of the Non-Extension Advance requested hereby
         (i) is $______________, which equals the Maximum Available Commitment
         on the date hereof and is to be applied in respect of the funding of
         the Class B Cash Collateral Account in accordance with Section 3.6(d)
         of the Intercreditor Agreement, (ii) does not include any amount with
         respect to the payment of the principal of, or premium on, the Class B
         Certificates, or principal of, or interest or premium on, the Class A
         Certificates or the Class C Certificates, (iii) was computed in
         accordance with the provisions of the Class B Certificates, the Class B
         Trust Agreement and the Intercreditor Agreement (a copy of which
         computation is attached hereto as Schedule I), and (iv) has not been
         and is not the subject of a prior or contemporaneous Notice of
         Borrowing under the Liquidity Agreement.

                  (4) Upon receipt by or on behalf of the Borrower of the amount
         requested hereby, (a) the Borrower will deposit such amount in the
         Class B Cash Collateral Account and apply the same in accordance with
         the terms of Section 3.6(d) of the Intercreditor Agreement, (b) no
         portion of such amount shall be applied by the Borrower for any other
         purpose and (c) no portion of such amount until so applied shall be
         commingled with other funds held by the Borrower.

                  The Borrower hereby acknowledges that, pursuant to the
Liquidity Agreement, (A) the making of the Non-Extension Advance as requested by
this Notice of Borrowing shall automatically and irrevocably terminate the
obligation of the Liquidity Provider to make further Advances under the
Liquidity Agreement; and (B) following the making by the Liquidity Provider of
the Non-Extension Advance requested by this Notice of Borrowing, the Borrower
shall not be entitled to request any further Advances under the Liquidity
Agreement.

                                      II-1
<PAGE>   35
                  IN WITNESS WHEREOF, the Borrower has executed and delivered
this Notice of Borrowing as of the ____ day of _________, ____.


                                       WILMINGTON TRUST COMPANY,
                                             not in its individual capacity but
                                             solely as Subordination Agent, as
                                             Borrower

                                       By:_________________________________
                                            Name:
                                            Title:

                                      II-2
<PAGE>   36
             SCHEDULE I TO NON-EXTENSION ADVANCE NOTICE OF BORROWING

[Insert Copy of computations in accordance with Non-Extension Advance Notice of
Borrowing]

                                      II-3
<PAGE>   37
                                                                    Annex III to
                                                      Revolving Credit Agreement

                      DOWNGRADE ADVANCE NOTICE OF BORROWING

                  The undersigned, a duly authorized signatory of the
undersigned subordination agent (the "Borrower"), hereby certifies to ABN AMRO
BANK N.V., Chicago Branch (the "Liquidity Provider"), with reference to the
Revolving Credit Agreement (1998-1B) dated as of October 6, 1998, between the
Borrower and the Liquidity Provider (the "Liquidity Agreement"; the terms
defined therein and not otherwise defined herein being used herein as therein
defined or referenced), that:

                  (1) The Borrower is the Subordination Agent under the
         Intercreditor Agreement.

                  (2) The Borrower is delivering this Notice of Borrowing for
         the making of the Downgrade Advance by the Liquidity Provider to be
         used for the funding of the Class B Cash Collateral Account in
         accordance with Section 3.6(c) of the Intercreditor Agreement by reason
         of the downgrading of the short-term unsecured debt rating of the
         Liquidity Provider issued by either Rating Agency below the Threshold
         Rating, which Advance is requested to be made on __________, ____.

                  (3) The amount of the Downgrade Advance requested hereby (i)
         is $________________, which equals the Maximum Available Commitment on
         the date hereof and is to be applied in respect of the funding of the
         Class B Cash Collateral Account in accordance with Section 3.6(c) of
         the Intercreditor Agreement, (ii) does not include any amount with
         respect to the payment of the principal of, or premium on, the Class B
         Certificates, or principal of, or interest or premium on, the Class A
         Certificates or the Class C Certificates, (iii) was computed in
         accordance with the provisions of the Class B Certificates, the Class B
         Trust Agreement and the Intercreditor Agreement (a copy of which
         computation is attached hereto as Schedule I), and (iv) has not been
         and is not the subject of a prior or contemporaneous Notice of
         Borrowing under the Liquidity Agreement.

                  (4) Upon receipt by or on behalf of the Borrower of the amount
         requested hereby, (a) the Borrower will deposit such amount in the
         Class B Cash Collateral Account and apply the same in accordance with
         the terms of Section 3.6(c) of the Intercreditor Agreement, (b) no
         portion of such amount shall be applied by the Borrower for any other
         purpose and (c) no portion of such amount until so applied shall be
         commingled with other funds held by the Borrower.

                  The Borrower hereby acknowledges that, pursuant to the
Liquidity Agreement, (A) the making of the Downgrade Advance as requested by
this Notice of Borrowing shall automatically and irrevocably terminate the
obligation of the Liquidity Provider to make further Advances under the
Liquidity Agreement; and (B) following the making by the Liquidity
<PAGE>   38
Provider of the Downgrade Advance requested by this Notice of Borrowing, the
Borrower shall not be entitled to request any further Advances under the
Liquidity Agreement.

                  IN WITNESS WHEREOF, the Borrower has executed and delivered
this Notice of Borrowing as of the ____ day of _________, ____.

                                      WILMINGTON TRUST COMPANY,
                                             not in its individual capacity but
                                             solely as Subordination Agent, as
                                             Borrower


                                      By:_________________________________
                                           Name:
                                           Title:
<PAGE>   39
               SCHEDULE I TO DOWNGRADE ADVANCE NOTICE OF BORROWING

[Insert Copy of computations in accordance with Downgrade Advance Notice of
Borrowing]
<PAGE>   40
                                                                     Annex IV to
                                                      Revolving Credit Agreement

                        FINAL ADVANCE NOTICE OF BORROWING

                  The undersigned, a duly authorized signatory of the
undersigned borrower (the "Borrower"), hereby certifies to ABN AMRO BANK N.V.,
Chicago Branch (the "Liquidity Provider"), with reference to the Revolving
Credit Agreement (1998-1B) dated as of October 6, 1998, between the Borrower and
the Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and
not otherwise defined herein being used herein as therein defined or
referenced), that:

                  (1) The Borrower is the Subordination Agent under the
         Intercreditor Agreement.

                  (2) The Borrower is delivering this Notice of Borrowing for
         the making of the Final Advance by the Liquidity Provider to be used
         for the funding of the Class B Cash Collateral Account in accordance
         with Section 3.6(i) of the Intercreditor Agreement by reason of the
         receipt by the Borrower of a Termination Notice from the Liquidity
         Provider with respect to the Liquidity Agreement, which Advance is
         requested to be made on ____________, ____.

                  (3) The amount of the Final Advance requested hereby (i) is
         $_________________, which equals the Maximum Available Commitment on
         the date hereof and is to be applied in respect of the funding of the
         Class B Cash Collateral Account in accordance with Section 3.6(i) of
         the Intercreditor Agreement, (ii) does not include any amount with
         respect to the payment of principal of, or premium on, the Class B
         Certificates, or principal of, or interest or premium on, the Class A
         Certificates or the Class C Certificates, (iii) was computed in
         accordance with the provisions of the Class B Certificates, the Class B
         Trust Agreement and the Intercreditor Agreement (a copy of which
         computation is attached hereto as Schedule I), and (iv) has not been
         and is not the subject of a prior or contemporaneous Notice of
         Borrowing.

                  (4) Upon receipt by or on behalf of the Borrower of the amount
         requested hereby, (a) the Borrower will deposit such amount in the
         Class B Cash Collateral Account and apply the same in accordance with
         the terms of Section 3.6(i) of the Intercreditor Agreement, (b) no
         portion of such amount shall be applied by the Borrower for any other
         purpose and (c) no portion of such amount until so applied shall be
         commingled with other funds held by the Borrower.

                  The Borrower hereby acknowledges that, pursuant to the
Liquidity Agreement, (A) the making of the Final Advance as requested by this
Notice of Borrowing shall automatically and irrevocably terminate the obligation
of the Liquidity Provider to make further Advances under the Liquidity
Agreement; and (B) following the making by the Liquidity Provider of the Final
Advance requested by this Notice of Borrowing, the Borrower shall not be
entitled to request any further Advances under the Liquidity Agreement.

                                      IV-1
<PAGE>   41
                  IN WITNESS WHEREOF, the Borrower has executed and delivered
this Notice of Borrowing as of the ____ day of _________, ____.

                                    WILMINGTON TRUST COMPANY,
                                             not in its individual capacity but
                                             solely as Subordination Agent, as
                                             Borrower

                                    By:_________________________________
                                         Name:
                                         Title:
<PAGE>   42
                 SCHEDULE I TO FINAL ADVANCE NOTICE OF BORROWING

[Insert Copy of Computations in accordance with Final Advance Notice of
Borrowing]
<PAGE>   43
                                                                      Annex V to
                                                      Revolving Credit Agreement




                              NOTICE OF TERMINATION



                                     [Date]



Wilmington Trust Company,
  as Subordination Agent, as Borrower
Rodney Square North
1100 North Market Square
Wilmington, DE  19890-0001


Re:      Revolving Credit Agreement dated as of October 6, 1998, between
         Wilmington Trust Company, as Subordination Agent, as agent and trustee
         for the America West Airlines Pass Through Trust, 1998-1B-[O/S], as
         Borrower, and ABN AMRO Bank N.V., Chicago Branch, as the Liquidity
         Provider (the "Liquidity Agreement")


Ladies and Gentlemen:

                  You are hereby notified that pursuant to Section 6.01 of the
Liquidity Agreement, by reason of the occurrence of a Liquidity Event of Default
and the existence of a Performing Note Deficiency (each as defined therein), we
are giving this notice to you in order to cause (i) our obligations to make
Advances (as defined therein) under such Liquidity Agreement to terminate on the
fifth Business Day after the date on which you receive this notice and (ii) you
to request a Final Advance under the Liquidity Agreement pursuant to Section
3.6(i) of the Intercreditor Agreement (as defined in the Liquidity Agreement) as
a consequence of your receipt of this notice.

                                      V-1
<PAGE>   44
                  THIS NOTICE IS THE "NOTICE OF TERMINATION" PROVIDED FOR UNDER
THE LIQUIDITY AGREEMENT. OUR OBLIGATIONS TO MAKE ADVANCES UNDER THE LIQUIDITY
AGREEMENT WILL TERMINATE ON THE FIFTH BUSINESS DAY AFTER THE DATE ON WHICH YOU
RECEIVE THIS NOTICE.

                                            Very truly yours,

                                            ABN AMRO BANK N.V., Chicago Branch
                                                as Liquidity Provider

                                            By:_________________________________
                                                 Name:
                                                 Title:


                                            By:_________________________________
                                                 Name:
                                                 Title:
cc:      WILMINGTON TRUST COMPANY,
           as Class B Trustee

                                      V-2
<PAGE>   45
                                                                     Annex VI to
                                                      Revolving Credit Agreement

                    NOTICE OF REPLACEMENT SUBORDINATION AGENT

[Date]
Attention:

         Revolving Credit Agreement dated as of October 6, 1998, between
         WILMINGTON TRUST COMPANY, as Subordination Agent, as agent and trustee
         for the America West Airlines Pass Through Trust, 1998-1B-[O/S], as
         Borrower, and ABN AMRO Bank N.V., Chicago Branch, as the Liquidity
         Provider (the "Liquidity Agreement")


Ladies and Gentlemen:

                  For value received, the undersigned beneficiary hereby
irrevocably transfers to:

                         ------------------------------
                              [Name of Transferee]


                         ------------------------------
                             [Address of Transferee]

all rights and obligations of the undersigned as Borrower under the Liquidity
Agreement referred to above. The transferee has succeeded the undersigned as
Subordination Agent under the Intercreditor Agreement referred to in the first
paragraph of the Liquidity Agreement, pursuant to the terms of Section 8.1 of
the Intercreditor Agreement.

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


                                      VI-1
<PAGE>   46
                  We ask that this transfer be effective as of _______________,
____.

                                    WILMINGTON TRUST COMPANY,
                                             not in its individual capacity but
                                             solely as Subordination Agent, as
                                             Borrower

                                    By:_________________________________
                                         Name:
                                         Title:

                                      VI-2