<PAGE>

                                                                     EXHIBIT 4.6

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

                       REVOLVING CREDIT AGREEMENT(2000-3C)

                          Dated as of November 2, 2000

                                     between

               STATE STREET BANK AND TRUST COMPANY OF CONNECTICUT,
                              NATIONAL ASSOCIATION
  as Subordination Agent, as agent and trustee for the US Airways Pass Through
                                  Trust 2000-3C

                                   as Borrower

                                       and

           MORGAN STANLEY CAPITAL SERVICES INC., as Liquidity Provider

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

                                   Relating to

                      US Airways Pass Through Trust 2000-3C
                   8.39% US Airways Pass Through Certificates,
                                 Series 2000-3C

<PAGE>

                                TABLE OF CONTENTS

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

ARTICLE II  AMOUNT AND TERMS OF THE COMMITMENT............................   8
         Section 2.01.  The Advances......................................   8
         Section 2.02.  Making the Advances...............................   8
         Section 2.03.  Fees..............................................  10
         Section 2.04.  Reductions, Increases or Termination of
                        the Maximum Commitment............................  10
         Section 2.05.  Repayments of Interest Advances or the
                        Final Advance.....................................  11
         Section 2.06.  Repayments of Provider Advances...................  11
         Section 2.07.  Payments to the Liquidity Provider Under
                        the Intercreditor Agreement.......................  12
         Section 2.08.  Book Entries......................................  12
         Section 2.09.  Payments from Available Funds Only................  13
         Section 2.10.  Extension of the Expiry Date; Non-Extension
                        Advance...........................................  13

ARTICLE III  OBLIGATIONS OF THE BORROWER..................................  13
         Section 3.01.  Increased Costs...................................  13
         Section 3.02.  Capital Adequacy..................................  14
         Section 3.03.  Payments Free of Deductions.......................  15
         Section 3.05.  Computations......................................  17
         Section 3.06.  Payment on Non-Business Days......................  17
         Section 3.07.  Interest..........................................  17
         Section 3.08.  Replacement of Borrower...........................  18
         Section 3.09.  Funding Loss Indemnification......................  18
         Section 3.10.  Illegality........................................  19

ARTICLE IV  CONDITIONS PRECEDENT..........................................  19
         Section 4.01.  Conditions Precedent to Effectiveness
                        of Section 2.01...................................  19
         Section 4.02.  Conditions Precedent to Borrowing.................  21

ARTICLE V  COVENANTS......................................................  21
         Section 5.01.  Affirmative Covenants of the Borrower.............  21
         Section 5.02.  Negative Covenants of the Borrower................  22

ARTICLE VI  LIQUIDITY EVENTS OF DEFAULT...................................  22
         Section 6.01.  Liquidity Events of Default.......................  22

ARTICLE VII  MISCELLANEOUS................................................  23
         Section 7.01.  Amendments, Etc...................................  23
         Section 7.02.  Notices, Etc......................................  23
         Section 7.03.  No Waiver; Remedies...............................  24
         Section 7.04.  Further Assurances................................  24
         Section 7.05.  Indemnification; Survival of Certain
                        Provisions........................................  24
         Section 7.06.  Liability of the Liquidity Provider...............  25
         Section 7.07.  Costs, Expenses and Taxes.........................  26
         Section 7.08.  Binding Effect; Participations....................  26
         Section 7.09.  Severability......................................  28
         Section 7.10.  GOVERNING LAW.....................................  28
         Section 7.11.  Submission to Jurisdiction; Waiver of Jury
                        Trial; Waiver of Immunity.........................  28
         Section 7.12.  Execution in Counterparts.........................  29
         Section 7.13.  Entirety..........................................  29
         Section 7.14.  Headings..........................................  29
         Section 7.15.  LIQUIDITY PROVIDER'S OBLIGATION TO MAKE ADVANCES..  29

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

EXHIBIT I Form of Guarantee Agreement
</TABLE>
<PAGE>

                      REVOLVING CREDIT AGREEMENT (2000-3C)

      This REVOLVING CREDIT AGREEMENT (2000-3C) dated as of November 2, 2000,
between STATE STREET BANK AND TRUST COMPANY OF CONNECTICUT, NATIONAL
ASSOCIATION, a national banking association, not in its individual capacity but
solely as Subordination Agent under the Intercreditor Agreement (each as defined
below), as agent and trustee for the Class C Trust (as defined below) (the
"Borrower"), and MORGAN STANLEY CAPITAL SERVICES INC., a corporation organized
under the laws of the State of Delaware (the "Liquidity Provider").

                                   WITNESSETH:

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

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

      WHEREAS, the Liquidity Provider has requested Morgan Stanley Dean Witter &
Co. (the "Guarantor") to enter into a Guarantee Agreement in the form attached
hereto as Exhibit I, providing for the full and unconditional guarantee of the
Liquidity Provider's obligations under this Agreement (the "Guarantee
Agreement").

      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(f).

      "Applicable Margin" means (x) with respect to any Unpaid Advance or
Applied Provider Advance, 2.0% per annum and (y) with respect to

<PAGE>

any Unapplied Provider Advance, the rate per annum specified in the Liquidity
Facility Fee Letter applicable to this Agreement.

      "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).

      "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%) per annum.

      "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 other day
on which insurance companies or commercial banks in New York, New York, or
commercial banking institutions in Pittsburgh, Pennsylvania and in the cities in
which the Corporate Trust Office of the Subordination Agent or any Loan Trustee
or the fiscal agent of the Policy Provider or the office of the Policy Provider
are located are authorized or obligated by law or executive order to close.

      "Deposit Agreement" means the Deposit Agreement dated as of the date
hereof between First Security Bank, National Association, as Escrow Agent and
ABN AMRO Bank N.V., acting through its Chicago branch, as Depositary, pertaining
to the Class C Certificates, as the same may be amended, modified or
supplemented from time to time in accordance with the terms thereof.

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

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

      "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.
<PAGE>

      "Excluded Taxes" means (i) taxes imposed on the overall net income of the
Liquidity Provider or of its Facility Office by the jurisdiction where such
Liquidity Provider's principal office or such Facility 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 Facility Office,
after the date on which such successor Liquidity Provider obtains its interest
or on which the Facility 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 31, 2001, initially, or any date to which the
Expiry Date is extended pursuant to Section 2.10.

      "Facility Office" means the Facility Office of the Liquidity Provider
presently located at New York, New York, or such other Facility Office as the
Liquidity Provider from time to time shall notify the Borrower as its Facility
Office hereunder; provided that the Liquidity Provider shall not change its
Facility Office to another Facility Office outside the United States of America
except in accordance with Section 3.01, 3.02 or 3.03 hereof.

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

      "Guarantor" has the meaning assigned to such term in the preliminary
statements of this Agreement.

      "Guarantee Agreement" has the meaning assigned to such term in the
preliminary statements of this Agreement.

      "Intercreditor Agreement" means the Intercreditor Agreement dated the date
hereof, among the Class C Trustee, the Class G Trustee, the Liquidity Provider,
the Policy Provider and the Subordination Agent, as the same may be amended,
supplemented or otherwise modified from time to time in accordance with its
terms.

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

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

      (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

<PAGE>

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

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

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

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

      "LIBOR Rate" means, with respect to any Interest Period:

      (i)   the rate per annum appearing on display page 3750 (British Bankers
            Association-LIBOR) of the Dow Jones Markets Service (or any
            successor or substitute therefor ) at approximately 11:00 a.m.
            (London time) two Business Days before the first day of such
            Interest Period, as the rate for dollar deposits with a maturity
            comparable to such Interest Period, or

      (ii)  if the rate calculated pursuant to clause (i) above is not
            available, the average (rounded upwards, if necessary, to the next
            1/16 of 1%) of the rates per annum at which deposits in dollars are
            offered for the relevant Interest Period by three banks of
            recognized standing selected by the Liquidity Provider in the London
            interbank market at approximately 11:00 a.m. (London time) two
            Business Days before the first day of such Interest Period in an
            amount approximately equal to the principal amount of the LIBOR
            Advance to which such Interest Period is to apply and for a period
            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 $250,000,000) or (b) a US
Airways Bankruptcy Event.

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

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

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

      "Maximum Commitment" means initially $19,765,246, as the same may be
reduced or increased from time to time in accordance with Section 2.04(a).

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

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

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

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

      "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.

      "Prospectus Supplement" means the Prospectus Supplement dated October 26,
2000 relating to the Certificates, as such Prospectus Supplement may be amended
or supplemented.

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

      "Reference Bank" has the meaning specified in Section 7.08(a).

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

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

      "Required Amount" means, for any day, the sum of the aggregate amount of
interest, calculated at the rate per annum equal to the Stated Interest Rate for
the Class C Certificates, that would be payable on the Class C Certificates on
each of the three successive semiannual Regular Distribution Dates immediately
following such day or, if such day is a Regular Distribution Date, on such day
and the succeeding two semiannual Regular Distribution Dates, in each case
calculated on the basis of the Pool Balance of the Class C Certificates on such
day and without regard to expected future payments of principal on the Class C
Certificates. Notwithstanding the above, in the event of any Policy Provider
Election, for purposes of the definition of the Required Amount, the Pool
Balance shall be deemed to be reduced by the amount (if positive) by which (a)
the then outstanding principal balance of each Series G Equipment Note in
respect of which such Policy Provider Election has been made shall exceed (b)
the amount of any Policy Drawings previously paid by the Policy Provider in
respect of principal on such Series G Equipment Note.
<PAGE>

      "Termination Date" means the earliest to occur of the following: (i) the
Expiry Date; (ii) the date on which the Borrower delivers to the Liquidity
Provider a certificate, signed by a Responsible Officer of the Borrower,
certifying that all of the Class C Certificates have been paid in full (or
provision has been made for such payment in accordance with the Intercreditor
Agreement and the Class C Trust Agreement) or are otherwise no longer entitled
to the benefits of this Agreement; (iii) the date on which the Borrower delivers
to the Liquidity Provider a certificate, signed by a Responsible Officer of the
Borrower, certifying that a Replacement Liquidity Facility has been substituted
for this Agreement in full pursuant to Section 3.6(e) of the Intercreditor
Agreement; (iv) the fifth Business Day following the receipt by the Borrower 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 Non-Extension Advance" means any Non-Extension Advance other
than an Applied Non-Extension 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", "Certificates", "Class G Certificates", "Class C Cash
Collateral Account", "Class C Certificateholders", "Class C Certificates",
"Class C Trust", "Class C Trust Agreement", "Class C Trustee", "Closing Date",
"Controlling Party", "Corporate Trust Office", "Delivery Period Expiry Date",
"Distribution Date", "Downgraded Facility", "Equipment Notes", "Final Legal
Distribution Date", "Financing Agreement", "Indenture", "Interest Payment Date",
"Investment Earnings", "Leased Aircraft", "Liquidity Facility", "Liquidity
Facility Fee Letter", "Liquidity Obligations", "Loan Trustee", "Moody's",
"Non-Extended Facility", "Note Purchase Agreement", "Operative Agreements",
"Owned Aircraft", "Participation Agreement", "Performing Equipment Note",
"Person", "Policy Drawings", "Policy Provider", "Policy Provider Election",
"Pool Balance", "Rating Agency", "Ratings Confirmation", "Regular Distribution
Date", "Replacement Liquidity Facility", "Responsible Officer", "Scheduled
Payment", "Series G Equipment Note", "Special Payment", "Standard & Poor's",
"Stated Interest Rate", "Subordination Agent", "Taxes", "Threshold Rating",
"Trustee", "Underwriters", "Underwriting Agreement", "US Airways", "US Airways
Bankruptcy Event" and "Written Notice".
<PAGE>

                                   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 1:00 p.m. (New York City time) on the Expiry Date (unless
the obligations of the Liquidity Provider shall be earlier terminated in
accordance with the terms of Section 2.04(b)) in an aggregate amount at any time
outstanding not to exceed the Maximum Commitment.

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

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

      (c) A Downgrade Advance shall be made in a single Borrowing upon a
downgrading of the Guarantor's short-term unsecured debt rating issued by either
Rating Agency below the applicable Threshold Rating or the Guarantee Agreement
ceasing to be in full force and effect or becoming invalid or unenforceable or
the Guarantor denying its liability thereunder (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) and 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 III attached hereto,
signed by a Responsible Officer of the Borrower, in an amount equal to the
Maximum Available Commitment at such time, and shall be used to fund the Class C
Cash Collateral Account in accordance with said Section 3.6(c) and Section
3.6(f) of the Intercreditor Agreement.

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

      (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 4:00 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 in 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. If the Liquidity Provider
makes an Advance requested pursuant to a Notice of Borrowing before 12:00 noon
(New York City time) on the second Business Day after the date of payment
specified in said Section 2.02(e), the Liquidity Provider shall have fully
discharged its obligations hereunder with respect to such Advance and an event
of default shall not have occurred hereunder. Following the making of any
Advance pursuant to Section 2.02(b), (c) or (d) hereof to fund the Class C Cash
Collateral Account, the Liquidity Provider shall have no interest in or rights
to the Class C Cash Collateral Account, such Advance or any other amounts from
time to time on deposit in the Class C Cash Collateral Account; provided that
the foregoing shall not affect or impair the obligations of the Subordination
Agent to make the distributions contemplated by Section 3.6(e) or (f) of the
Intercreditor Agreement. By paying to the Borrower proceeds of Advances
requested by the Borrower in accordance with the provisions of this Agreement,
the Liquidity Provider makes no representation as to, and assumes no
responsibility for, the correctness or sufficiency for any purpose of the amount
of the Advances so made and requested.

      Section 2.03. Fees. The Borrower agrees to pay to the Liquidity Provider
the fees set forth in the Liquidity Facility Fee Letter applicable to this
Agreement.
<PAGE>

      Section 2.04. Reductions, Increases or Termination of the Maximum
Commitment.

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

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

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

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

thereon; provided further, however, that if, following the making of a Provider
Advance, the Liquidity Provider delivers a Termination Notice to the Borrower
pursuant to Section 6.01 hereof, such Provider Advance shall thereafter be
treated as a Final Advance under this Agreement for purposes of determining the
Applicable Liquidity Rate for interest payable thereon. Subject to Sections 2.07
and 2.09 hereof, immediately upon the withdrawal of any amounts from the Class C
Cash Collateral Account on account of a reduction in the Required Amount, the
Borrower shall repay to the Liquidity Provider a portion of the Provider
Advances in a principal amount equal to such reduction, plus interest on the
principal amount prepaid as provided in Section 3.07 hereof.

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

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

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

      Section 2.08. Book Entries. The Liquidity Provider shall maintain in
accordance with its usual practice an account or accounts evidencing the
indebtedness of the Borrower resulting from Advances made from time to time and
the amounts of principal and interest payable hereunder and paid from time to
time in respect thereof; provided, however, that the 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 6(c)
or 6(b), as the case may be, of the Participation Agreements and Section 7 of
the Note Purchase Agreement and
<PAGE>

only to the extent that the Borrower shall have sufficient income or proceeds
therefrom to enable the Borrower to make payments in accordance with the terms
hereof after giving effect to the priority of payments provisions set forth in
the Intercreditor Agreement. The Liquidity Provider agrees that it will look
solely to such amounts to the extent available for distribution to it as
provided in the Intercreditor Agreement and this Agreement and that the
Borrower, in its individual capacity, is not personally liable to it for any
amounts payable or liability under this Agreement except as expressly provided
in this Agreement, the Intercreditor Agreement or any Participation Agreement.
Amounts on deposit in the Class C Cash Collateral Account shall be available to
the Borrower to make payments under this Agreement only to the extent and for
the purposes expressly contemplated in Section 3.6(f) of the Intercreditor
Agreement.

      Section 2.10. Extension of the Expiry Date; Non-Extension Advance. The
Expiry Date shall be automatically extended, effective on the 25th day prior to
each Expiry Date, for a period of 364 days after such Expiry Date (unless the
obligations of the Liquidity Provider are earlier terminated in accordance with
the terms hereof), without the necessity of any act on the part of the Borrower
or the Liquidity Provider, unless the Liquidity Provider shall advise the
Borrower prior to such 25th day that it does not agree to such extension of such
Expiry Date, in which event (and 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 such 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.

                                   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 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), 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) by any court, central bank
or monetary authority charged with the interpretation or administration thereof
(a "Regulatory Change"), which: (1) changes the basis of taxation of any amounts
payable to the Liquidity Provider under this Agreement in respect of any such
Advances (other than Excluded Taxes); or (2) imposes or modifies any reserve,
special deposit, compulsory loan or similar requirements relating to any
extensions of credit or other assets of, or any deposits with other liabilities
of, the Liquidity Provider (including any such Advances or any deposits referred
to in the definition of LIBOR Rate or related definitions). The Liquidity
Provider agrees to use reasonable efforts (consistent with applicable legal and
regulatory restrictions) to change the jurisdiction of its Facility 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 disadvantageous to
the Liquidity Provider.
<PAGE>

      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. 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.

      Notwithstanding the preceding two paragraphs, the Liquidity Provider and
the Subordination Agent agree that the initial Liquidity Provider (i.e., Morgan
Stanley Capital Services Inc.) shall not be entitled to the benefits of the
preceding two paragraphs; provided, however, any permitted assignee or
participant of the initial Liquidity Provider which is a bank organized under
the laws of the United States or any State thereof shall be entitled to the
benefits of the preceding two paragraphs (subject, in the case of any permitted
participant, to the limitations set forth in Section 7.08 hereof).

      Section 3.02. Capital Adequacy. If (1) the adoption, after the date
hereof, of any applicable governmental law, rule or regulation regarding capital
adequacy, (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
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, by any central bank or other
governmental authority (whether or not having the force of law) 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 Facility
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. 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>

      Notwithstanding the preceding two paragraphs, the Liquidity Provider and
the Subordination Agent agree that the initial Liquidity Provider (i.e., Morgan
Stanley Capital Services Inc.) shall not be entitled to the benefits of the
preceding two paragraphs; provided, however, any permitted assignee or
participant of the initial Liquidity Provider which is a bank organized under
the laws of the United States or any State thereof shall be entitled to the
benefits of the preceding two paragraphs (subject, in the case of any permitted
participant, to the limitations set forth in Section 7.08 hereof).

      Section 3.03. Payments Free of Deductions. (a) All payments made by the
Borrower under this Agreement shall be made free and clear of, and without
reduction for or on account of, any present or future stamp or other taxes,
levies, imposts, duties, charges, fees, deductions, withholdings, restrictions
or conditions of any nature whatsoever now or hereafter imposed, levied,
collected, withheld or assessed, excluding Excluded Taxes (such non-excluded
taxes being referred to herein, collectively, as "Non-Excluded Taxes" and,
individually, as 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 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) interest or any other such amounts payable under this
Agreement at the rates or in the amounts specified in this Agreement. The
Liquidity Provider agrees to use reasonable efforts (consistent with its
internal policy and legal and regulatory restrictions) to change the
jurisdiction of its Facility Office if making such change would avoid the need
for, or reduce the amount of, any such additional amounts that may thereafter
accrue and would not, in the reasonable judgment of the Liquidity Provider, be
otherwise disadvantageous to the Liquidity Provider. From time to time upon the
reasonable request of the Borrower, if the Liquidity Provider is not organized
under the laws of the United States or any State thereof, the Liquidity Provider
agrees to provide to the Borrower two original Internal Revenue Service Form
W-8BEN or W-8ECI, 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.

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

      (c) If any exemption from, or reduction in the rate of, any Taxes is
reasonably available to the Borrower to establish that payments under this
Agreement are exempt from (or entitled to a reduced rate of) Tax, the Borrower
shall deliver to the Liquidity Provider such form or forms and such other
evidence of the eligibility of the Borrower
<PAGE>

for such exemption or reduction as the Liquidity Provider may reasonably
identify to the Borrower as being required as a condition to exemption from, or
reduction in the rate of, any Taxes.

      Section 3.04. Payments. The Borrower shall make or cause to be made each
payment to the Liquidity Provider under this Agreement so as to cause the same
to be received by the Liquidity Provider not later than 1:00 p.m. (New York City
time) on the day when due. The Borrower shall make all such payments in lawful
money of the United States of America, to the Liquidity Provider in immediately
available funds, by wire transfer to Citibank, N.A., New York, NY, ABA#
021000089, Account Name: Morgan Stanley Capital Services Inc., in favor of
account number 4072-4601, Reference: US Airways, Inc. EETC 2000-3.

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

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

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

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

      (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 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 2.00% 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 Borrower. From time to time and subject to
the successor Borrower's meeting the eligibility requirements set forth in
Section 6.9 of the Intercreditor Agreement applicable to the Subordination
Agent, upon the effective date and time specified in a written and completed
Notice of Replacement Subordination Agent in substantially the form of Annex VI
attached hereto (a "Notice of Replacement Subordination Agent") delivered to the
Liquidity Provider by the then Borrower, the successor Borrower designated
therein shall be substituted for as the Borrower for all purposes hereunder.

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

      (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, or any
change in the interpretation or administration thereof by any governmental
authority, central bank or comparable agency charged with the interpretation or
administration thereof, or compliance by the Liquidity Provider (or its Facility
Office) with any request or directive (whether or not having the force of law)
of any such authority, central bank or comparable agency shall make it unlawful
or impossible for the Liquidity Provider (or its Facility Office) to maintain or
fund its LIBOR Advances, then upon notice to the Borrower by the Liquidity
Provider, the outstanding principal amount of the LIBOR Advances shall be
converted to Base Rate Advances (a) immediately upon demand of the Liquidity
Provider, if such change or compliance with such request, in the judgment of the
Liquidity Provider, requires immediate repayment; or (b) at the expiration of
the last Interest Period to expire before the effective date of any such change
or request.

                                   ARTICLE IV

                              CONDITIONS PRECEDENT

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

      (a) The Liquidity Provider shall have received on or before the Closing
Date each of the following, and in the case of each document delivered pursuant
to paragraphs (i), (ii) and (iii), 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 Prospectus Supplement and specimen copies of the Class
            C Certificates;

      (v)   An executed copy of each document, instrument, certificate and
            opinion delivered on or before the Closing Date pursuant to the
            Class C Trust Agreement, the Intercreditor Agreement and the other
            Operative Agreements (in the case of each such opinion, other than
            the opinion of counsel for the Underwriters, 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);
<PAGE>

      (vi)   Evidence that there shall have been made and shall be in full force
             and effect, all filings, recordings and/or registrations, and there
             shall have been given or taken any notice or other similar action
             as may be reasonably necessary or, to the extent reasonably
             requested by the Liquidity Provider, reasonably advisable, in order
             to establish, perfect, protect and preserve the right, title and
             interest, remedies, powers, privileges, liens and security
             interests of, or for the benefit of, the Class C Trustee, the
             Borrower and the Liquidity Provider created by the Operative
             Agreements executed and delivered on or prior to the Closing Date;

      (vii)  An agreement from US Airways, pursuant to which (i) US Airways
             agrees to provide copies of quarterly financial statements and
             audited annual financial statements to the Liquidity Provider, and
             such other information as the Liquidity Provider shall reasonably
             request with respect to the transactions contemplated by the
             Operative Agreements, in each case, only to the extent that US
             Airways is obligated to provide such information pursuant to
             Section 16 of the Basic Lease or Section 7 of the Special Leased
             Aircraft Participation Agreement (related to Leased Aircraft) to
             the extent such provisions require delivery of financial
             statements, or the corresponding section of the Indentures (related
             to Owned Aircraft) to the parties thereto and (ii) US Airways
             agrees to allow the Liquidity Provider to inspect US Airways' books
             and records regarding such transactions, and to discuss such
             transactions with officers and employees of US Airways; and

      (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 the account of the Liquidity
Provider on or prior to the Effective Date.

      (d) All conditions precedent to the issuance of the Class C Certificates
under the Class C Trust Agreement shall have been satisfied or waived, and 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 Class C Certificates by Airbus Industrie Financial Services
under the Purchase Agreement shall have been satisfied (unless any of such
conditions precedent shall have been waived by Airbus Industrie Financial
Services).
<PAGE>

      (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.

      (f) The Borrower shall have received the Guarantee Agreement,
substantially in the form of Exhibit I hereto, duly executed on behalf of the
party thereto.

      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.

      (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
<PAGE>

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.

      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:             State Street Bank and Trust Company of
                              Connecticut, National Association
                          225 Asylum Street
                          Goodwin Square
                          Hartford, CT  06103
                          Attention: Corporate/Muni. Department
                          Telephone: (860) 244-1822
                          Telecopy: (860) 244-1889

                          with a copy to:

                          State Street Bank and Trust Company
                          Corporate Trust Department
                          2 Avenue de Lafayette
                          Boston, MA  02110

                          Attention: Ruth A. Smith
                          Telecopy: (617) 662-1465

    Liquidity Provider:   Morgan Stanley Capital Services Inc.
                          1585 Broadway
                          New York, NY  10036

                          Attention: [Elinor Hoover/Ivana Komarcevic/
                          Mark Esparrago]
                          Telephone: (212) 761-2522/1895/2618
                          Telecopy: (302) 651-8882
<PAGE>

with a copy of any Notice of Borrowing to:

                               Morgan Stanley Dean Witter & Co.
                               1585 Broadway
                               3rd Floor
                               New York, NY  10036

                               Attention: James Hill, Legal Department
                               Telephone: (212) 762-6829
                               Telecopy: (212) 762-8896

or, as to each of the foregoing, at such other address as shall be
designated by such Person in a written notice to the others. All such
notices and communications shall be effective (i) if given by telecopier,
when transmitted to the telecopier number specified above and (ii) if given
by other means, when delivered at the address specified above, except that
written notices to the Liquidity Provider pursuant to the provisions of
Articles II and III hereof shall not be effective until received by the
Liquidity Provider. A copy of all notices delivered hereunder to either
party shall in addition be delivered to each of the parties to the
Participation Agreements at their respective addresses set forth therein.

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

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

      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 6(c) of the Leased Aircraft Participation
Agreements, Section 6(b) of the Owned Aircraft Participation Agreements or
Section 7(c) of the Note Purchase Agreement, as the case may be. In addition,
the Borrower agrees to indemnify, protect, defend and hold harmless the
Liquidity Provider from, against and in respect of, and shall pay on demand, all
Expenses of any kind or nature whatsoever (other than any Expenses of the nature
described in Section 3.01, 3.02 or 7.07 hereof or in the Liquidity Facility Fee
Letter applicable to this Agreement (regardless of whether indemnified against
pursuant to said Sections or in such Liquidity Facility Fee Letter)), that may
be imposed, incurred by or asserted against any Liquidity Indemnitee, in any way
relating to, resulting from, or arising out of or in connection with any action,
suit or proceeding by any third party against such Liquidity Indemnitee and
relating to this Agreement, the Liquidity Facility Fee Letter applicable to this
Agreement, the Intercreditor Agreement or any Financing Agreement; provided,
however, that the Borrower shall not be required to indemnify, protect, defend
and hold harmless any Liquidity Indemnitee in respect of any Expense of such
Liquidity Indemnitee to the extent such Expense is (i) attributable to the gross
negligence or willful misconduct of such Liquidity Indemnitee or any other
Liquidity Indemnitee, (ii) ordinary and usual operating overhead expense, or
(iii) attributable to the failure by such Liquidity Indemnitee or any other
Liquidity Indemnitee to perform or
<PAGE>

observe any agreement, covenant or condition on its part to be performed or
observed in this Agreement, the Intercreditor Agreement, the Liquidity Facility
Fee Letter applicable to this Agreement or any other Operative Agreement to
which it is a party. The indemnities contained in Section 6(c) of the Leased
Aircraft Participation Agreements or 6(b) of the Owned Aircraft Participation
Agreements, as the case may be, 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; (ii) the validity, sufficiency or
genuineness of documents, or of any endorsement thereon, even if such documents
should prove to be in any or all respects invalid, insufficient, fraudulent or
forged; or (iii) the making of Advances by the Liquidity Provider against
delivery of a Notice of Borrowing and other documents which do not comply with
the terms hereof; provided, however, that the Borrower shall have a claim
against the Liquidity Provider, and the Liquidity Provider shall be liable to
the Borrower, to the extent of any damages suffered by the Borrower which were
the result of (A) the Liquidity Provider's willful misconduct or negligence in
determining whether documents presented hereunder comply with the terms hereof,
or (B) any breach by the Liquidity Provider of any of the terms of this
Agreement, including, but not limited to, the Liquidity Provider's failure to
make lawful payment hereunder after the delivery to it by the Borrower of a
Notice of Borrowing 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 Agreement
or such other documents which may be delivered in connection herewith or
therewith (whether or not the same shall become effective) or (iii) any action
or proceeding relating to any order, injunction, or other process or decree
restraining or seeking to restrain the Liquidity Provider from paying any amount
under this Agreement, the Intercreditor Agreement or any other Operative
Agreement or otherwise affecting the application of funds in the Class C Cash
Collateral Account. In addition, the Borrower shall pay any and all recording,
stamp and other similar taxes and fees payable or determined to be payable in
connection with the execution,
<PAGE>

delivery, filing and recording of this Agreement, any other Operative Agreement
and such other documents, and agrees to save the Liquidity Provider harmless
from and against any and all liabilities with respect to or resulting from any
delay in paying or omission to pay such taxes or fees.

      Section 7.08. Binding Effect; Participations. (a) This Agreement shall be
binding upon and inure to the benefit of the Borrower and the Liquidity Provider
and their respective successors and assigns, except that neither the Liquidity
Provider (except as otherwise provided in this Section 7.08) nor (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 (other than US Airways or any of its
affiliates) as the Liquidity Provider may in its sole discretion select, subject
to the requirements of Section 7.08(b). No such participation by the Liquidity
Provider, however, 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. 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(a) and the like as they pertain to the Liquidity Provider shall
be deemed also to include those of each of its participants that are banks
(subject, in each case, if any such participant is not a bank that is (i)
organized under the laws of the United States or any State thereof and (ii) a
member bank of the Federal Reserve System with deposits exceeding $1,000,000,000
(such a bank, a "Reference Bank"), to the maximum amount that would have been
directly incurred by any Reference Bank organized under the laws of the United
States or any State thereof if such Reference Bank, 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 state
thereof or (y) if it is not so incorporated, two copies of a properly completed
United States Internal Revenue Service Form W-8ECI or Form W-8BEN, as
appropriate, or other applicable form, certificate or document prescribed by the
Internal Revenue Service certifying, in each case, such 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 W-8ECI or Form W-8BEN, as appropriate, (A) on or before
the date that any such form expires or becomes obsolete or (B) after the
occurrence of any event requiring a change in the most recent form previously
delivered by it and prior to the immediately following due date of any payment
by the Borrower hereunder, certifying in the case of a
<PAGE>

Form W-8BEN or Form W-8ECI 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 such action or proceeding in any such court or
            that such action or proceeding was brought in an inconvenient court
            and agrees not to plead or claim the same;

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

      (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.

      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.

      Section 7.15. LIQUIDITY PROVIDER'S OBLIGATION TO MAKE ADVANCES. EXCEPT AS
EXPRESSLY SET FORTH IN THIS AGREEMENT, THE OBLIGATIONS OF THE LIQUIDITY PROVIDER
TO MAKE ADVANCES HEREUNDER, AND THE BORROWER'S RIGHTS TO DELIVER NOTICES OF
BORROWING REQUESTING THE MAKING OF ADVANCES HEREUNDER, SHALL BE UNCONDITIONAL
AND IRREVOCABLE, AND SHALL BE PAID OR PERFORMED, IN EACH CASE STRICTLY IN
ACCORDANCE WITH THE TERMS OF THIS AGREEMENT.
<PAGE>

      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.

                                          STATE STREET BANK AND TRUST
                                          COMPANY OF CONNECTICUT, NATIONAL
                                          ASSOCIATION, not in its
                                          individual capacity but solely as
                                          Subordination Agent, as agent and
                                          trustee for the Class C Trust, as
                                          Borrower

                                          By /s/ John G. Correia
                                             ----------------------------------
                                          Name: John G. Correia
                                          Title:   Assistant Vice President

                                          MORGAN STANLEY CAPITAL SERVICES INC.,
                                          as Liquidity Provider

                                          By /s/ Elinor L. Hoover
                                             ----------------------------------
                                          Name: Elinor L. Hoover
                                          Title: Vice President


<PAGE>

                                         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 Morgan Stanley Capital Services
Inc. (the "Liquidity Provider"), with reference to the Revolving Credit
Agreement (2000-3C) dated as of November 2, 2000, 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 the interest on the
      Class C Certificates which was payable on ____________, ____ (the
      "Distribution Date") in accordance with the terms and provisions of the
      Class C Trust Agreement and the Class C Certificates, which Advance is
      requested to be made on ____________, ____. The Interest Advance should be
      transferred to [name of bank/wire instructions/ABA number] in favor of
      account number [ __ ], reference [ __ ].

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

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

            The Borrower hereby acknowledges that, pursuant to the Liquidity
Agreement, the making of the Interest Advance as requested by this Notice of
Borrowing shall automatically reduce, subject to reinstatement in accordance
with the terms of the Liquidity Agreement, the Maximum Available Commitment by
an amount equal to the amount of the Interest Advance requested to be made
hereby as set forth in clause (i) of paragraph (3) of this Notice of Borrowing
and such reduction shall automatically result in corresponding reductions in the
amounts available to be borrowed pursuant to a subsequent Advance.
<PAGE>

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

                                          STATE STREET BANK AND TRUST
                                          COMPANY OF CONNECTICUT, NATIONAL
                                          ASSOCIATION, not in its
                                          individual capacity but solely as
                                          Subordination Agent, as Borrower

                                          By: _______________________________
                                          Name:
                                          Title:

<PAGE>

               SCHEDULE I TO INTEREST ADVANCE NOTICE OF BORROWING

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

                                                                    Annex II to
                                                     Revolving Credit Agreement

                  NON-EXTENSION ADVANCE NOTICE OF BORROWING

            The undersigned, a duly authorized signatory of the undersigned
borrower (the "Borrower"), hereby certifies to Morgan Stanley Capital Services
Inc. (the "Liquidity Provider"), with reference to the Revolving Credit
Agreement (2000-3C) dated as of November 2, 2000, between the Borrower and the
Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and not
otherwise defined herein being used herein as therein defined or referenced),
that:

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

            (2) The Borrower is delivering this Notice of Borrowing for the
      making of the Non-Extension Advance by the Liquidity Provider to be used
      for the funding of the Class C Cash Collateral Account in accordance with
      Section 3.6(d) of the Intercreditor Agreement, which Advance is requested
      to be made on __________, ____. The Non-Extension Advance should be
      transferred to [name of bank/wire instructions/ABA number] in favor of
      account number [ __ ], reference [ __ ].

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

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

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

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

                                          STATE STREET BANK AND TRUST
                                          COMPANY OF CONNECTICUT, NATIONAL
                                          ASSOCIATION, not in its
                                          individual capacity but solely as
                                          Subordination Agent, as Borrower

                                          By: ________________________________
                                          Name:
                                          Title:

<PAGE>

          SCHEDULE I TO NON-EXTENSION ADVANCE NOTICE OF BORROWING

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


<PAGE>

                                                                    Annex III to
                                                      Revolving Credit Agreement

                      DOWNGRADE ADVANCE NOTICE OF BORROWING

            The undersigned, a duly authorized signatory of the undersigned
borrower (the "Borrower"), hereby certifies to Morgan Stanley Capital Services
Inc. (the "Liquidity Provider"), with reference to the Revolving Credit
Agreement (2000-3C) dated as of November 2, 2000, between the Borrower and the
Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and not
otherwise defined herein being used herein as therein defined or referenced),
that:

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

            (2) The Borrower is delivering this Notice of Borrowing for the
      making of the Downgrade Advance by the Liquidity Provider to be used for
      the funding of the Class C Cash Collateral Account in accordance with
      Section 3.6(c) of the Intercreditor Agreement (i) by reason of the
      downgrading of the short-term unsecured debt rating of the Guarantor
      issued by either Rating Agency below the Threshold Rating or (ii) because
      the Guarantee Agreement has ceased to be in full force and effect or has
      become invalid or unenforceable or the Guarantor has denied its liability
      thereunder, which Advance is requested to be made on __________, ____. The
      Downgrade Advance should be transferred to [name of bank/wire
      instructions/ABA number] in favor of account number [ __ ], reference
      [ __ ].

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

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

            The Borrower hereby acknowledges that, pursuant to the Liquidity
Agreement, (A) the making of the Downgrade Advance as requested by this Notice
of Borrowing shall automatically and irrevocably terminate the obligation of the
Liquidity Provider to make further Advances under the Liquidity Agreement; and
(B) following the making by the Liquidity 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.
<PAGE>

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

                                          STATE STREET BANK AND TRUST
                                          COMPANY OF CONNECTICUT, NATIONAL
                                          ASSOCIATION, not in its
                                          individual capacity but solely as
                                          Subordination Agent, as Borrower

                                          By: _________________________________
                                          Name:
                                          Title:


<PAGE>

               SCHEDULE I TO DOWNGRADE ADVANCE NOTICE OF BORROWING

 [Insert Copy of computations in accordance with Downgrade Advance Notice
of Borrowing]
<PAGE>

                                                                     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 Morgan Stanley Capital Services
Inc. (the "Liquidity Provider"), with reference to the Revolving Credit
Agreement (2000-3C) dated as of November 2, 2000, between the Borrower and the
Liquidity Provider (the "Liquidity Agreement"; the terms defined therein and not
otherwise defined herein being used herein as therein defined or referenced),
that:

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

            (2) The Borrower is delivering this Notice of Borrowing for the
      making of the Final Advance by the Liquidity Provider to be used for the
      funding of the Class C Cash Collateral Account in accordance with Section
      3.6(i) of the Intercreditor Agreement by reason of the receipt by the
      Borrower of a Termination Notice from the Liquidity Provider with respect
      to the Liquidity Agreement, which Advance is requested to be made on
      ____________, ____. The Final Advance should be transferred to [name of
      bank/wire instructions/ABA number] in favor of account number [ __ ],
      reference [ __ ].

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

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

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

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

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

                                          STATE STREET BANK AND TRUST
                                          COMPANY OF CONNECTICUT, NATIONAL
                                          ASSOCIATION, not in its
                                          individual capacity but solely as
                                          Subordination Agent, as Borrower

                                          By _________________________________
                                          Name:
                                          Title:

<PAGE>

                 SCHEDULE I TO FINAL ADVANCE NOTICE OF BORROWING

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

                                                                      Annex V to
                                                      Revolving Credit Agreement

                              NOTICE OF TERMINATION

                                                       [Date]

State Street Bank and Trust Company of
   Connecticut, National Association,
   as Subordination Agent, as Borrower
225 Asylum Street
Goodwin Square
Hartford, CT  06103

Attention:  Corporate Trust Administration

            Revolving Credit Agreement dated as of November 2, 2000, between
            State Street Bank and Trust Company of Connecticut, National
            Association, as Subordination Agent, as agent and trustee for the US
            Airways Pass Through Trust, 2000-3C, as Borrower, and Morgan Stanley
            Capital Services Inc. (the "Liquidity Agreement")

Ladies and Gentlemen:

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

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

                                          Very truly yours,

                                          Morgan Stanley Capital Services Inc.,
                                          as Liquidity Provider

                                          By ________________________________
                                          Name:
                                          Title:

cc: State Street Bank and Trust Company of
    Connecticut, National Association,
    as Class C Trustee

<PAGE>

                                                                   Annex VI to
                                                    Revolving Credit Agreement

                 NOTICE OF REPLACEMENT SUBORDINATION AGENT

[Date]
Attention:

         Revolving Credit Agreement dated as of November 2, 2000, between
         State Street Bank and Trust Company of Connecticut, National
         Association, as Subordination Agent, as agent and trustee for the
         US Airways Pass Through Trust, 2000-3C, as Borrower, and Morgan
         Stanley Capital Services Inc. (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.


<PAGE>

            We ask that this transfer be effective as of _______________, ____.

                                          STATE STREET BANK AND TRUST
                                          COMPANY OF CONNECTICUT, NATIONAL
                                          ASSOCIATION, not in its
                                          individual capacity but solely as
                                          Subordination Agent, as Borrower

                                          By _________________________________
                                          Name:
                                          Title:

                                          By _________________________________
                                          Name:
                                          Title:

<PAGE>

                                                                  EXHIBIT I to
                                                    Revolving Credit Agreement

                           FORM OF GUARANTEE AGREEMENT

                                              _________ __, 2000

US Airways Pass Through Trust 2000-3C
Ladies and Gentlemen:

      In consideration of the Revolving Credit Agreement (the "Agreement") dated
as of _____ __, 2000 between Morgan Stanley Capital Services Inc., a Delaware
corporation (hereinafter "MSCS") and State Street Bank and Trust Company of
Connecticut, National Association, as Subordination Agent, as agent and trustee
for the US Airways Pass Through Trust 2000-3C ("Counterparty"), Morgan Stanley
Dean Witter & Co., a Delaware corporation (hereinafter "MSDW"), hereby
irrevocably and unconditionally guarantees to Counterparty, with effect from the
date of the Agreement, the due and punctual payment of all amounts payable by
MSCS under the Agreement when the same shall become due and payable, whether on
scheduled payment dates, upon demand, upon declaration of termination or
otherwise, in accordance with the terms of the Agreement and giving effect to
any applicable grace period under the express terms of the Agreement. Upon
failure of MSCS punctually to pay any such amounts, MSDW agrees to pay or cause
to be paid such amounts. It is understood and agreed that the obligations of
MSCS under the Agreement to make Advances (as defined in the Agreement) are, and
shall in any event, for all purposes of the Guarantee, be deemed to constitute,
amounts payable by MSCS under the Agreement.

      MSDW hereby agrees that its obligations hereunder shall be unconditional
and will not be discharged except by complete payment of the amounts payable
under the Agreement, irrespective of any claim as to the Agreement's validity,
regularity or enforceability or the lack of authority of MSCS to execute or
deliver the Agreement; or any change in or amendment to the Agreement; or any
waiver or consent by Counterparty with respect to any provisions thereof; or the
absence of any action to enforce the Agreement or the recovery of any judgment
against MSCS or of any action to enforce a judgment against MSCS under the
Agreement; or any similar circumstance which might otherwise constitute a legal
or equitable discharge or defense of a guarantor generally. MSDW hereby waives
diligence, presentment, demand on MSDW or MSCS for payment or otherwise, filing
of claims, requirement of a prior proceeding against MSCS and protest or notice,
except as provided for in the Agreement with respect to amounts payable by MSCS.
If at any time payment under the Agreement is rescinded or must be otherwise
restored or returned by Counterparty upon the insolvency, bankruptcy or
reorganization of MSCS or MSDW or otherwise, MSDW's obligations hereunder with
respect to such payment shall be reinstated upon such restoration or return
being made by Counterparty.

<PAGE>

      MSDW represents to Counterparty as of the date hereof that:

      (1) it is duly organized and validly existing under the laws of the
jurisdiction of its incorporation and has full power and legal right to execute
and deliver this Guarantee and to perform the provisions of this Guarantee on
its part to be performed;

      (2) its execution, delivery and performance of this Guarantee have been
and remain duly authorized by all necessary corporate action and do not
contravene any provision of its certificate of incorporation or by-laws or any
law, regulation or contractual restriction binding on it or its assets;

      (3) all consents, authorizations, approvals and clearances (including,
without limitation, any necessary exchange control approval) and notifications,
reports and registrations requisite for its due execution, delivery and
performance of this Guarantee have been obtained from or, as the case may be,
filed with the relevant governmental authorities having jurisdiction and remain
in full force and effect and all conditions thereof have been duly complied with
and no other action by, and no notice to or filing with, any governmental
authority having jurisdiction is required for such execution, delivery or
performance; and

      (4) this Guarantee is its legal, valid and binding obligation enforceable
against it in accordance with its terms except as enforcement hereof may be
limited by applicable bankruptcy, insolvency, reorganization or other similar
laws affecting the enforcement of creditors' rights or by general equity
principles.

      By accepting this Guarantee and entering into the Agreement, Counterparty
agrees that MSDW shall be subrogated to all rights of Counterparty against MSCS
in respect of any amounts paid by MSDW pursuant to this Guarantee, provided that
MSDW shall be entitled to enforce or to receive any payment arising out of or
based upon such right of subrogation only to the extent that it has paid all
amounts payable by MSCS under the Agreement.

      This Guarantee shall be governed by and construed in accordance with the
laws of the State of New York. All capitalized terms not otherwise defined
herein shall have the respective meanings assigned to them in the Agreement.

                                          MORGAN STANLEY DEAN WITTER & CO.

                                          By _____________________________
                                          Name:
                                          Title:

                                          Address: 1585 Broadway
                                                   3rd Floor
                                                   New York, NY  10036
                                          Attention: Swap Group
                                          Fax No.: (212) 761-0162

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