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                                                                     EXHIBIT 4.5

                          TRUST SUPPLEMENT No. 2000-3C
                          Dated as of November 2, 2000

                                     between

               STATE STREET BANK AND TRUST COMPANY OF CONNECTICUT,
                              NATIONAL ASSOCIATION
                                   as Trustee,

                                       and

                                US AIRWAYS, INC.

                                       to

                          PASS THROUGH TRUST AGREEMENT
                           Dated as of October 5, 2000

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

            This Trust Supplement No. 2000-3C, dated as of November 2, 2000
(herein called the "Trust Supplement"), between US Airways, Inc., a Delaware
corporation (the "Company") and State Street Bank and Trust Company of
Connecticut, National Association (the "Trustee"), to the Pass Through Trust
Agreement, dated as of October 5, 2000, between the Company and the Trustee (the
"Basic Agreement").

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                                   WITNESSETH:

            WHEREAS, the Basic Agreement, unlimited as to the aggregate
principal amount of Certificates (unless otherwise specified herein, capitalized
terms used herein without definition having the respective meanings specified in
the Basic Agreement) which may be issued thereunder, has heretofore been
executed and delivered;

            WHEREAS, the Company obtained commitments from AVSA for the delivery
of twenty-three (23) Aircraft;

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

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

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

            WHEREAS, the Trustee hereby declares the creation of this US Airways
Pass Through Trust 2000-3C (the "Applicable Trust") for the benefit of the
Applicable Certificateholders, and the initial Applicable Certificateholders as
the grantors of the Applicable Trust, by their respective acceptances of the
Applicable Certificates, join in the creation of the Applicable Trust with the
Trustee;

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

            WHEREAS, the Escrow Agent, the Trustee, the Escrow Paying Agent, and
AIFS have contemporaneously herewith entered into an Escrow Agreement with the
Escrow Paying Agent pursuant to which AIFS has delivered to the Escrow Agent the
proceeds from the sale of the Applicable Certificates and has irrevocably
instructed the Escrow Agent to withdraw and pay funds from such proceeds upon
request and proper certification by the Trustee to purchase Equipment Notes as
the Aircraft are delivered by AVSA under the Aircraft Purchase Agreement from
time to time prior to the Delivery Period Termination Date;

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

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            WHEREAS, pursuant to the terms and conditions of the Basic Agreement
as supplemented by this Trust Supplement (the "Agreement") and the Note Purchase
Agreement, the Trustee on behalf of the Applicable Trust, using funds withdrawn
under the Escrow Agreement, shall purchase one or more Equipment Notes having
the same interest rate as, and Final Legal Distribution Date not later than the
final Regular Distribution Date of, the Applicable Certificates issued hereunder
and, in each case, shall hold such Equipment Notes in trust for the benefit of
the Applicable Certificateholders; and

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

            NOW THEREFORE, in consideration of the premises herein, it is agreed
between the Company and the Trustee as follows:

                                    ARTICLE I
                                THE CERTIFICATES

            Section 1.01. The Certificates. There is hereby created a series of
certificates to be issued under the Agreement to be distinguished and known as
"8.39% US Airways Pass Through Certificates, Series 2000-3C" (including any
Exchange Certificates and any Private Exchange Certificates) (hereinafter
defined as the "Applicable Certificates"). Each Applicable Certificate
represents a fractional undivided interest in the Applicable Trust created
hereby. The Applicable Certificates shall be the only instruments evidencing a
fractional undivided interest in the Applicable Trust.

            The terms and conditions applicable to the Applicable Certificates
are as follows:

            (a) The aggregate principal amount of the Applicable Certificates
      that shall be authenticated under the Agreement (except for Applicable
      Certificates authenticated and delivered pursuant to Sections 3.03, 3.04
      and 3.06 of the Basic Agreement and in connection with the Registration
      Agreement) is $157,054,000.

            (b) The Regular Distribution Dates with respect to any payment of
      Scheduled Payments means March 1 and September 1 of each year, commencing
      on March 1, 2001, until payment of all of the Scheduled Payments to be
      made under the Equipment Notes has been made.

            (c) The Special Distribution Dates with respect to the Applicable
      Certificates means any Business Day on which a Special Payment is to be
      distributed pursuant to the Agreement.

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

            (e) (i) The Applicable Certificates shall be in the form attached
      hereto as Exhibit A. Any Person acquiring or accepting an Applicable
      Certificate or an interest therein will, by such acquisition or
      acceptance, be deemed to represent and warrant that either (i) the assets
      of an employee benefit plan subject to Title I of the Employee Retirement
      Income Security Act of 1974, as amended ("ERISA"), or of a plan subject to
      Section 4975 of the Internal Revenue Code of 1986, as amended (the
      "Code"), have not been used to purchase Applicable Certificates or an
      interest therein or (ii) the purchase and holding of Applicable
      Certificates is exempt from the prohibited transaction restrictions of
      ERISA and the Code pursuant to one or more prohibited transaction
      statutory or administrative exemptions.

            (ii) The Applicable Certificates shall be Book-Entry Certificates
      and shall be subject to the conditions set forth in the Letter of
      Representations between the Company and the Clearing Agency attached
      hereto as Exhibit E.

            (f) The Applicable Certificates are subject to the Intercreditor
      Agreement, the Deposit Agreement and the Escrow Agreement.

            (g) The Applicable Certificates will have the benefit of the
      Liquidity Facility and the Registration Agreement.

            (h) The Responsible Party is the Company.

            (i) The particular "sections of the Note Purchase Agreement", for
      purposes of clause (3) of Section 7.07 of the Basic Agreement, are Section
      6(b) (with respect to Owned Aircraft) and Section 6(c) (with respect to
      Leased Aircraft) of the relevant Participation Agreement attached as an
      exhibit to the Note Purchase Agreement.

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                                   ARTICLE II
                                   DEFINITIONS

            Section 2.01. Definitions. Capitalized terms used but not otherwise
defined herein shall have the meaning ascribed to them in the Basic Agreement.
For all purposes of the Basic Agreement as supplemented by this Trust
Supplement, the following capitalized terms have the following meanings:

            Agreement: Has the meaning specified in the recitals hereto.

            AIFS: Means Airbus Industrie Financial Services.

            Aircraft: Means each of the New Aircraft or Substitute Aircraft in
      respect of which a Participation Agreement is entered into in accordance
      with the Note Purchase Agreement.

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

            Applicable Certificate: Has the meaning specified in Section 1.01 of
      this Agreement.

            Applicable Certificateholder: Means the Person in whose name an
      Applicable Certificate is registered on the Register for the Applicable
      Certificates.

            Applicable Delivery Date: Has the meaning specified in Section
      5.01(b) of this Trust Supplement.

            Applicable Participation Agreement: Has the meaning specified in
      Section 5.01(b) of this Trust Supplement.

            AVSA: Means AVSA, S.A.R.L.

            Business Day: Means any day other than a Saturday, a 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 Prover are located are authorized or obligated by law or
      executive order to close.

            Class C Purchase Agreement: Means the Purchase Agreement dated as of
      October 26, 2000 between AIFS and the Company, as the same may be amended,
      supplemented or otherwise modified from time to time in accordance with
      its terms.

            Class G Agreement: Means the Basic Agreement as supplemented by the
      Trust Supplement No. 2000-3G.

            Class G Certificates: Means the 7.89% US Airways Pass Through
      Certificates, Series 2000-3G.

            Class G Certificateholder: Means a holder of Class G Certificates.

            Class G Trustee: Means the Trustee under the Class G Agreement.

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            Closing Notice: Means the Closing Notice as defined in and delivered
      pursuant to Section 2(b) of the Note Purchase Agreement.

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

            Delivery Date: Has the meaning specified in the Participation
      Agreements.

            Delivery Notice: Has the meaning specified in the Participation
      Agreements.

            Delivery Period Termination Date: Means the earlier of (a) July 1,
      2001 and (b) the date on which Equipment Notes issued with respect to all
      of the New Aircraft (or Substitute Aircraft in lieu thereof) have been
      purchased by the Applicable Trust and the Class G Trust in accordance with
      the Note Purchase Agreement.

            Deposits: Has the meaning specified in the Deposit Agreement.

            Deposit Agreement: Means the Deposit Agreement dated as of November
      2, 2000 relating to the Applicable Certificates between the Depositary and
      the Escrow Agent, as the same may be amended, supplemented or otherwise
      modified from time to time in accordance with its terms.

            Depositary: Means ABN AMRO Bank N.V., acting through its Chicago
      branch, and any replacement or successor therefor.

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

            Escrow Agent: Means, initially, First Security Bank, National
      Association, and any replacement or successor therefor appointed in
      accordance with the Escrow Agreement.

            Escrow Agreement: Means the Escrow and Paying Agent Agreement dated
      as of November 2, 2000 relating to the Applicable Certificates, among the
      Escrow Agent, the Escrow Paying Agent, the Trustee and AIFS, as the same
      may be amended, supplemented or otherwise modified from time to time in
      accordance with its terms.

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

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

            Exchange Certificate: Means any of the certificates, substantially
      in the form of Exhibit A, issued in exchange for an Initial Certificate
      pursuant to the Registration Agreement and authenticated under this
      Agreement.

<PAGE>

            Exchange Offer Registration Statement: Means the Exchange Offer
      Registration Statement defined in the Registration Agreement.

            Final Legal Distribution Date: Means, with respect to the Applicable
      Certificates, September 1, 2023.

            Final Withdrawal: Has the meaning specified in Section 1.2 of the
      Escrow Agreement.

            Final Withdrawal Date: Has the meaning specified in Section 1.2 of
      the Escrow Agreement.

            Final Withdrawal Notice: Has the meaning specified in Section 5.02
      of this Trust Supplement.

            Global Certificates: Has the meaning assigned to such term in
      Section 9.01(a).

            Indenture: Means each of the separate trust indentures and mortgages
      relating to the Aircraft, in each case as the same may be amended,
      supplemented or otherwise modified from time to time in accordance with
      its terms.

            Initial Certificate: Means any of the certificates issued and
      authenticated, under this Agreement, substantially in the form of Exhibit
      A, other than an Exchange Certificate or a Private Exchange Certificate.

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

            Intercreditor Agreement: Means the Intercreditor Agreement dated as
      of November 2, 2000 among the Trustee, the Class G Trustee, the Liquidity
      Provider, the Policy Provider, and State Street Bank and Trust Company of
      Connecticut, National Association, as Subordination Agent and as trustee
      thereunder, as amended, supplemented or otherwise modified from time to
      time in accordance with its terms.

            Investors: Means AIFS together with all subsequent beneficial owners
      of the Applicable Certificates.

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

            Leased Aircraft: Has the meaning specified in the third recital to
      this Trust Supplement.

<PAGE>

            Liquidity Facility: Means, initially, the Revolving Credit Agreement
      dated as of November 2, 2000 relating to the Applicable Certificates,
      between the Liquidity Provider and State Street Bank and Trust Company of
      Connecticut, National Association, as Subordination Agent, as agent and
      trustee for the Applicable Trust, and, from and after the replacement of
      such agreement pursuant to the Intercreditor Agreement, the replacement
      liquidity facility therefor, in each case as amended, supplemented or
      otherwise modified from time to time in accordance with their respective
      terms.

            Liquidity Provider: Means, initially, Morgan Stanley Capital
      Services Inc., and any replacements or successors therefor appointed in
      accordance with the Intercreditor Agreement.

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

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

            Note Documents: Means the Note Purchase Agreement, this Trust
      Supplement and, with respect to any Equipment Note, means (i) the
      Indenture and the Participation Agreement relating to such Equipment Note,
      and (ii) in the case of any Equipment Note related to a Leased Aircraft,
      the Lease relating to such Leased Aircraft.

            Note Purchase Agreement: Means the Note Purchase Agreement dated as
      of November 2, 2000 among the Trustee, the Class G Trustee, the Company,
      the Escrow Agent, the Escrow Paying Agent and the Subordination Agent,
      providing for, among other things, the purchase of certain Equipment Notes
      by the Trustee on behalf of the Trust, as the same may be amended,
      supplemented or otherwise modified from time to time, in accordance with
      its terms.

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

            Offering Memorandum: Means the Confidential Offering Memorandum,
      dated November 2, 2000, relating to the offering of the Applicable
      Certificates.

            Owned Aircraft: Has the meaning specified in the third recital to
      this Trust Supplement.

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

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

<PAGE>

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

            Physical Certificates: Has the meaning specified in Section
      10.01(b).

            Policy: Has the meaning specified in the Intercreditor Agreement.

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

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

            Pool Balance: Means, as of any date, (i) the original aggregate face
      amount of the Applicable Certificates less (ii) the aggregate amount of
      all payments made in respect of such Applicable Certificates or in respect
      of Deposits relating to the Applicable Trust other than payments made in
      respect of interest or premium thereon or reimbursement of any costs or
      expenses incurred in connection therewith. The Pool Balance as of any
      Distribution Date shall be computed after giving effect to any special
      distribution with respect to unused Deposits, payment of principal of the
      Equipment Notes or payment with respect to other Trust Property, and the
      distribution thereof to be made on that date.

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

            Private Exchange Certificate: Means any of the certificates,
      substantially in the form of Exhibit A, issued in exchange for an Initial
      Certificate pursuant to the Registration Agreement and authenticated under
      this Agreement.

            Private Placement Legend: Has the meaning specified in Section
      10.02(a).

            Prospectus Supplement: Means the Prospectus Supplement dated October
      26, 2000, relating to the offering of the Class G Certificates.

            PTC Event of Default: Means, with respect to the Applicable
      Certificates, any failure to pay within ten Business Days of the due date
      thereof: (i) the outstanding Pool Balance of the Applicable Certificates
      on the Final Legal Distribution Date for the Applicable Certificates or
      (ii) interest due on the Applicable Certificates on any Distribution Date
      (unless the Subordination Agent shall have made an Interest Drawing, or a
      withdrawal from the Cash Collateral Account or a drawing under the Policy
      with respect thereto in an aggregate amount sufficient to pay such
      interest and shall have distributed such amount to the Trustee).

<PAGE>

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

            Registration Agreement: Means the Registration Agreement, dated as
      of the date hereof, between the Initial Purchaser, the Trustee and the
      Company, as amended, supplemented or otherwise modified from time to time
      in accordance with its terms.

            Registration Statement: Means the Registration Statement defined in
      the Registration Agreement.

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

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

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

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

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

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

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

            Termination Date: Means the date on which first occurs a
      "Termination Event" as defined in that certain Aircraft Financing Letter
      Agreement, dated as of October 31, 1997 between AVSA, S.A.R.L. and the
      Company.

<PAGE>

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

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

                                   ARTICLE III
                 DISTRIBUTIONS; STATEMENTS TO CERTIFICATEHOLDERS

            Section 3.01. Additions to Article IV of the Basic Agreement. In
addition to the provisions of Article IV of the Basic Agreement, the following
provisions shall apply to the Applicable Trust:

            (a) Upon the payment of Special Redemption Premium to the Trustee
      under the Note Purchase Agreement, the Trustee, upon receipt thereof,
      shall immediately deposit the aggregate amount of such Special Redemption
      Premium in the Special Payments Account;

            (b) The distribution of amounts of Special Redemption Premium as
      provided for in Section 4.02(b) of the Basic Agreement shall be on the
      Special Distribution Date with respect to such Special Payment or as soon
      thereafter as the Trustee has confirmed receipt of the related Special
      Redemption Premium;

            (c) In the event of the payment of a Special Redemption Premium by
      the Company to the Trustee under the Note Purchase Agreement, the notice
      provided for in Section 4.02(c) of the Basic Agreement shall be mailed,
      together with the notice by the Escrow Paying Agent under Section 2.06 of
      the Escrow Agreement, not less than 15 days prior to the Special
      Distribution Date for such amount, which Special Distribution Date shall
      be the Final Withdrawal Date; and

            (d) The last sentence of the first paragraph of Section 4.02(c) of
      the Basic Agreement shall apply equally if the amount of Special
      Redemption Premium, if any, has not been calculated at the time the
      Trustee mails notice of a Special Payment.

<PAGE>

            Section 3.02. Statements to Applicable Certificateholders. (a) On
each Distribution Date, the Trustee will include with each distribution to
Applicable Certificateholders of a Scheduled Payment or Special Payment, as the
case may be, a statement setting forth the information provided below (in the
case of a Special Payment, including any Special Redemption Premium, reflecting
in part the information provided by the Escrow Paying Agent under the Escrow
Agreement). Such statement shall set forth (per $1,000 face amount Applicable
Certificate as to (ii), (iii), (iv) and (v) below) the following information:

            (i) the aggregate amount of funds distributed on such Distribution
      Date under the Agreement and under the Escrow Agreement, indicating the
      amount allocable to each source including any portion thereof paid by the
      Liquidity Provider;

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

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

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

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

            (vi) the Pool Balance and the Pool Factor.

            With respect to the Applicable Certificates registered in the name
of a Clearing Agency, on the Record Date prior to each Distribution Date, the
Trustee will request from such Clearing Agency a securities position listing
setting forth the names of all Clearing Agency Participants reflected on such
Clearing Agency's books as holding interests in the Applicable Certificates on
such Record Date. On each Distribution Date, the Trustee will mail to each such
Clearing Agency Participant the statement described above and will make
available additional copies as requested by such Clearing Agency Participant for
forwarding to holders of interests in the Applicable Certificates.

            (b) Within a reasonable period of time after the end of each
calendar year but not later than the latest date permitted by law, the Trustee
shall furnish to each Person who at any time during such calendar year was an
Applicable Certificateholder of record a statement containing the sum of the
amounts determined pursuant to clauses (a)(i), (a)(ii), (a)(iii), (a)(iv) and
(a)(v) of this Section 3.02 for such calendar year or, in the event such Person
was an Applicable Certificateholder of record during a portion of such calendar
year, for such portion of such year, and such other items as are readily
available to the Trustee and which an Applicable Certificateholder shall
reasonably request as necessary for the purpose of such Applicable
Certificateholder's preparation of its federal income tax returns. Such
statement and such other items shall be prepared on the basis of information
supplied to the Trustee by the Clearing Agency Participants and shall be
delivered by the Trustee to such Clearing Agency Participants to be available
for forwarding by such Clearing Agency Participants to the holders of interests
in the Applicable Certificates in the manner described in Section 3.02(a) of
this Trust Supplement.

<PAGE>

            (c) Promptly following (i) the Cut-Off Date, if there has been any
change in the information set forth in clauses (x), (y) and (z) below from that
set forth in page S-45 of the Prospectus Supplement, and (ii) any early
redemption or purchase of, or any default in the payment of principal or
interest in respect of, any of the Equipment Notes held in the Applicable Trust,
or any Final Withdrawal, the Trustee shall furnish to Applicable
Certificateholders of record on such date a statement setting forth (x) the
expected Pool Balances for each subsequent Regular Distribution Date following
the Cut-Off Date, (y) the related Pool Factors for such Regular Distribution
Dates and (z) the expected principal distribution schedule of the Equipment
Notes, in the aggregate, held as Trust Property at the date of such notice. With
respect to the Applicable Certificates registered in the name of a Clearing
Agency, on the Cut-Off Date, the Trustee will request from such Clearing Agency
a securities position listing setting forth the names of all Clearing Agency
Participants reflected on such Clearing Agency's books as holding interests in
the Applicable Certificates on such date. The Trustee will mail to each such
Clearing Agency Participant the statement described above and will make
available additional copies as requested by such Clearing Agency Participant for
forwarding to holders of interests in the Applicable Certificates.

            (d) This Section 3.02 supersedes and replaces Section 4.03 of the
      Basic Agreement.

                                   ARTICLE IV
                                     DEFAULT

            Section 4.01. Purchase Rights of Certificateholders. (a) (i) At any
time after the occurrence and during the continuance of a Triggering Event, each
Applicable Certificateholder shall have the right to purchase, for the purchase
price set forth below, all, but not less than all, of the Class G Certificates
upon ten days' written notice to the Trustee, and each other Applicable
Certificateholder, provided that (A) if prior to the end of such ten-day period
any other Applicable Certificateholder notifies such purchasing Applicable
Certificateholder that such other Applicable Certificateholder wants to
participate in such purchase, then such other Applicable Certificateholder may
join with the purchasing Applicable Certificateholder to purchase all, but not
less than all, of the Class G Certificates pro rata based on the Fractional
Undivided Interest in the Applicable Trust held by each such Applicable
Certificateholder and (B) if prior to the end of such ten-day period any other
Applicable Certificateholder fails to notify the purchasing Applicable
Certificateholder of such other Applicable Certificateholder's desire to
participate in such a purchase, then such other Applicable Certificateholder
shall lose its right to purchase the Class G Certificates pursuant to this
Section 4.01(a) and (ii) whether or not any Applicable Certificateholder
exercises its right to purchase pursuant to clause (a)(i) above, the Policy
Provider, if it is then the Controlling Party and 180 days have elapsed since
the occurrence of a Triggering Event that is continuing, shall have the right
(except in the event of a Policy Provider Default) to purchase all, but not less
than all, of the Class G Certificates upon ten days' written notice to the
Trustee, the trustee of the Class G Trust and the Class G Certificateholders.

<PAGE>

            The purchase price with respect to the Class G Certificates shall be
equal to the Pool Balance of the Class G Certificates, together with accrued and
unpaid interest thereon to the date of such purchase, without premium, but
including any other amounts then due and payable to the Class G
Certificateholders under this Agreement, the Intercreditor Agreement, the Escrow
Agreement or any Note Document or on or in respect of the Applicable
Certificates; provided, however, that (x) if such purchase occurs after the
record date specified in Section 2.03(b) of the Escrow Agreement relating to the
distribution of unused Deposits and accrued and unpaid interest thereunder, such
purchase price shall be reduced by the aggregate amount of unused Deposits and
interest to be distributed under the Escrow Agreement (which deducted amounts
shall remain distributable to, and may be retained by, the Class G
Certificateholder as of such Record Date) and (y) if such purchase occurs after
a Record Date, such purchase price shall be reduced by the amount to be
distributed hereunder on the related Distribution Date (which deducted amounts
shall remain distributable to, and may be retained by, the Class G
Certificateholder as of such Record Date); provided further that no such
purchase of Class G Certificates shall be effective unless the purchaser(s)
shall certify to the Trustee that contemporaneously with such purchase, such
purchaser(s) is purchasing the Class G Certificates pursuant to the terms of
this Agreement. Each payment of the purchase price of the Class G Certificates
referred to in the first sentence hereof shall be made to an account or accounts
designated by the Trustee and each such purchase shall be subject to the terms
of this Section 4.01(a).

            (b) This Section 4.01 supersedes and replaces Section 6.01(b) of the
      Basic Agreement.

                                    ARTICLE V
                                   THE TRUSTEE

            Section 5.01. Delivery of Documents; Delivery Dates. (a) The Trustee
is hereby directed (i) to execute and deliver the Intercreditor Agreement, the
Escrow Agreement, the Registration Agreement and the Note Purchase Agreement,
each in the form delivered to the Trustee by the Company and (ii) subject to the
respective terms thereof, to perform its obligations thereunder. Upon request of
the Company and the satisfaction or waiver of the closing conditions specified
in the Class C Purchase Agreement, the Trustee shall execute, deliver,
authenticate, issue and sell Applicable Certificates in authorized denominations
equaling in the aggregate the amount set forth, with respect to the Applicable
Trust, in Schedule I to the Class C Purchase Agreement evidencing the entire
ownership interest in the Applicable Trust, which amount equals the maximum
aggregate principal amount of Equipment Notes which may be purchased by the
Trustee pursuant to the Note Purchase Agreement. Except as provided in Sections
3.03, 3.04, 3.05 and 3.06 of the Basic Agreement, the Trustee shall not execute,
authenticate or deliver Applicable Certificates in excess of the aggregate
amount specified in this paragraph.

<PAGE>

            (b) On or after the Issuance Date the Company may deliver from time
to time to the Trustee a Closing Notice relating to one or more Equipment Notes.
After receipt of a Closing Notice and in any case no later than one Business Day
prior to a Delivery Date as to which such Closing Notice relates (the
"Applicable Delivery Date"), the Trustee shall (as and when specified in the
Closing Notice) instruct the Escrow Agent to provide a Notice of Purchase
Withdrawal to the Depositary requesting (A) the withdrawal of one or more
Deposits on the Applicable Delivery Date in accordance with and to the extent
permitted by the terms of the Escrow Agreement and the Deposit Agreement and (B)
the payment of all, or a portion, of such Deposit or Deposits in an amount equal
in the aggregate to the purchase price of such Equipment Notes to or on behalf
of the Owner Trustee or the Company, as the case may be, issuing such Equipment
Notes, all as shall be described in the Closing Notice. The Trustee shall (as
and when specified in such Closing Notice), subject to the conditions set forth
in Section 3 of the Note Purchase Agreement, enter into and perform its
obligations under the Participation Agreement specified in such Closing Notice
(the "Applicable Participation Agreement") and cause such certificates,
documents and legal opinions relating to the Trustee to be duly delivered as
required by the Applicable Participation Agreement. If at any time prior to the
Applicable Delivery Date, the Trustee receives a notice of postponement pursuant
to Section 2(e), 2(f), or 2(g) of the Note Purchase Agreement, then the Trustee
shall give the Depositary (with a copy to the Escrow Agent) a notice of
cancellation of such Notice of Purchase Withdrawal relating to such Deposit or
Deposits on such Applicable Delivery Date. Upon satisfaction of the conditions
specified in the Note Purchase Agreement and the Applicable Participation
Agreement, the Trustee shall purchase the applicable Equipment Notes with the
proceeds of the withdrawals of one or more Deposits made on the Applicable
Delivery Date in accordance with the terms of the Deposit Agreement and the
Escrow Agreement. The purchase price of such Equipment Notes shall equal the
principal amount of such Equipment Notes. Amounts withdrawn from such Deposit or
Deposits in excess of the purchase price of the Equipment Notes or to the extent
not applied on the Applicable Delivery Date to the purchase price of the
Equipment Notes, shall be re-deposited by the Trustee with the Depositary on the
Applicable Delivery Date in accordance with the terms of the Deposit Agreement.
The provisions of Section 5.01(a) hereof and this Section 5.01(b) supersede and
replace the provisions of Section 2.02 of the Basic Agreement (which are
inapplicable to the Trust), and all provisions of the Basic Agreement relating
to Section 2.02 of the Basic Agreement shall not apply to the Applicable Trust.

            Section 5.02. Withdrawal of Deposits. If any Deposits remain
outstanding on the Business Day next succeeding the Cut-off Date or on the
Termination Date, (i) the Trustee shall give the Escrow Agent notice that the
Trustee's obligation to purchase Equipment Notes under the Note Purchase
Agreement has terminated and instruct the Escrow Agent to provide a notice of
Final Withdrawal to the Depositary substantially in the form of Exhibit B to the
Deposit Agreement (the "Final Withdrawal Notice") and (ii) the Trustee will make
a demand upon the Company under the Note Purchase Agreement for an amount equal
to the Special Redemption Premium, such payment to be made on the Final
Withdrawal Date.

<PAGE>

            Section 5.03. The Trustee. (a) Subject to Section 5.04 of this Trust
Supplement and Section 7.15 of the Basic Agreement, the Trustee shall not be
responsible in any manner whatsoever for or in respect of the validity or
sufficiency of this Trust Supplement, the Deposit Agreement or the Escrow
Agreement or the due execution hereof or thereof by the Company or the other
parties thereto (other than the Trustee), or for or in respect of the recitals
and statements contained herein or therein, all of which recitals and statements
are made solely by the Company.

            (b) Except as herein otherwise provided, no duties, responsibilities
or liabilities are assumed, or shall be construed to be assumed by the Trustee
by reason of this Trust Supplement other than as set forth in the Basic
Agreement, and this Trust Supplement is executed and accepted on behalf of the
Trustee, subject to all the terms and conditions set forth in the Basic
Agreement, upon the effectiveness thereof, as fully to all intents as if the
same were herein set forth at length.

            Section 5.04. Representations and Warranties of the Trustee. The
Trustee hereby represents and warrants that:

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

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

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

<PAGE>

            (d) this Trust Supplement, the Intercreditor Agreement, the
      Registration Agreement, the Escrow Agreement and the Note Documents to
      which it is a party have been, or will be, as applicable, duly executed
      and delivered by the Trustee and constitute, or will constitute, as
      applicable, the legal, valid and binding agreements of the Trustee,
      enforceable against it in accordance with their respective terms;
      provided, however, that enforceability may be limited by (i) applicable
      bankruptcy, insolvency, reorganization, moratorium or similar laws
      affecting the rights of creditors generally and (ii) general principles of
      equity.

            Section 5.05. Trustee Liens. The Trustee in its individual capacity
agrees, in addition to the agreements contained in Section 7.17 of the Basic
Agreement, that it will at its own cost and expense promptly take any action as
may be necessary to duly discharge and satisfy in full any Trustee's Liens on or
with respect to the Trust Property which is attributable to the Trustee in its
individual capacity and which is unrelated to the transactions contemplated by
the Intercreditor Agreement or the Note Purchase Agreement.

                                   ARTICLE VI
                             SUPPLEMENTAL AGREEMENTS

            Section 6.01. Supplemental Agreements Without Consent of Applicable
Certificateholders. Under the terms of, and subject to the limitations contained
in, Section 9.01 of the Basic Agreement, the Company may (but will not be
required to), and the Trustee (subject to Section 9.03 of the Basic Agreement)
shall, at the Company's request, at any time and from time to time, enter into
one or more agreements supplemental to the Escrow Agreement, the Note Purchase
Agreement or the Deposit Agreement, for any of the purposes set forth in clauses
(1) through (9) of such Section 9.01, except that (a) clause (3) of such Section
9.01 shall be deemed to include the Company's rights and powers conferred by the
Note Purchase Agreement and (b) clause (4) of such Section 9.01 shall be deemed
to include corrections or supplements to provisions of the Escrow Agreement or
the Deposit Agreement which may be defective or inconsistent with any other
provision of this Agreement or contained in any agreement referred to in such
clause (4) and the curing of any ambiguity or the modification of any other
provision with respect to matters or questions arising under the Escrow
Agreement or the Deposit Agreement.

            Section 6.02. Supplemental Agreements with Consent of Applicable
Certificateholders. The provisions of Section 9.02 of the Basic Agreement shall
apply to agreements or amendments for the purpose of adding any provisions to or
changing in any manner or eliminating any of the provisions of the Escrow
Agreement, the Deposit Agreement or the Note Purchase Agreement to the extent
applicable to the Applicable Certificateholders approving such agreement or
amendment or modifying in any manner the rights and obligations of such
Applicable Certificateholders under the Escrow Agreement, the Deposit Agreement
or the Note Purchase Agreement; provided that the provisions of Section 9.02(1)
of the Basic Agreement shall be deemed to include reductions in any manner of,
or delay in the timing of, any receipt by the Applicable Certificateholders of
payments upon the Deposits. The provisions of Sections 9.01(9) and 9.01(10) of
the Basic Agreement shall not be applicable to this Trust Supplement.

<PAGE>

                                   ARTICLE VII
                              TERMINATION OF TRUST

            Section 7.01. Termination of the Trust. The respective obligations
and responsibilities of the Company and the Trustee with respect to the
Applicable Trust shall terminate upon the distribution to all Applicable
Certificateholders and the Trustee of all amounts required to be distributed to
them pursuant to this Agreement and the disposition of all property held as part
of the Trust Property; provided, however, that in no event shall the Applicable
Trust continue beyond 21 years less one day following the death of the last
survivor of all descendants living on the date hereof of Joseph P. Kennedy, Sr.,
unless applicable law shall permit a longer term, in which case such longer term
shall apply.

            Notice of any termination specifying the Distribution Date upon
which the Applicable Certificateholders may surrender their Applicable
Certificates to the Trustee for payment of the final distribution and
cancellation, shall be mailed promptly by the Trustee to Applicable
Certificateholders not earlier than the 60th day and not later than the 15th day
next preceding such final Distribution Date specifying (A) the Distribution Date
upon which the proposed final payment of the Applicable Certificates will be
made upon presentation and surrender of Applicable Certificates at the office or
agency of the Trustee therein specified, (B) the amount of any such proposed
final payment, and (C) that the Record Date otherwise applicable to such
Distribution Date is not applicable, payments being made only upon presentation
and surrender of the Applicable Certificates at the office or agency of the
Trustee therein specified. The Trustee shall give such notice to the Registrar
at the time such notice is given to Applicable Certificateholders. Upon
presentation and surrender of the Applicable Certificates in accordance with
such notice, the Trustee shall cause to be distributed to Applicable
Certificateholders such final payments.

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

<PAGE>

                                  ARTICLE VIII
                                   THE COMPANY

            Section 8.01. Consolidation, Mergers, Etc. Section 5.02 of the Basic
Agreement is hereby amended with respect to the Applicable Trust by deleting the
word "and" at the end of clause (b) thereof, renumbering clause (c) as clause
"(d)" and inserting a new clause (c) as follows:

            "(c) immediately after giving effect to such transaction, no
      Indenture Event of Default (in the case of an Owned Aircraft) or, in the
      case of a Leased Aircraft, Lease Event of Default (as defined in the
      related Indenture) shall have occurred and be continuing; and"

                                   ARTICLE IX
                            MISCELLANEOUS PROVISIONS

            Section 9.01. Basic Agreement Ratified. Except and so far as herein
expressly provided, all of the provisions, terms and conditions of the Basic
Agreement are in all respects ratified and confirmed; and the Basic Agreement
and this Trust Supplement shall be taken, read and construed as one and the same
instrument.

            Section 9.02. GOVERNING LAW. THIS AGREEMENT AND THE APPLICABLE
CERTIFICATES SHALL BE GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF
THE STATE OF NEW YORK.

            Section 9.03. Execution in Counterparts. This Trust Supplement may
be executed in any number of counterparts, each of which shall be an original,
but such counterparts shall together constitute but one and the same instrument.

            Section 9.04. Intention of Parties. The parties hereto intend that
the Applicable Trust be classified for U.S. federal income tax purposes as a
grantor trust under Subpart E, Part I of Subchapter J of the Internal Revenue
Code of 1986, as amended, and not as a trust or association taxable as a
corporation or as a partnership. Each Applicable Certificateholder and Investor,
by its acceptance of its Applicable Certificate or a beneficial interest
therein, agrees to treat the Applicable Trust as a grantor trust for all U.S.
federal, state and local income tax purposes. The powers granted and obligations
undertaken pursuant to the Agreement shall be so construed so as to further such
intent.

            Section 9.05. Benefits of Agreement. (a) Nothing in this Agreement
or in the Certificates of any series, express or implied, shall give to any
person, other than the parties hereto and their successors hereunder and the
Certificateholders of each series, any benefit or any legal or equitable right,
remedy or claim under this Agreement.

            (b) This Section 9.05 supercedes and replaces Section 12.10 of the
Basic Agreement.

<PAGE>

                                    ARTICLE X
                                THE CERTIFICATES

            Section 10.01. Additions to Article III of the Basic Agreement. In
addition to the provisions of Article III of the Basic Agreement, the following
provisions shall apply to the Applicable Trust:

            (a) Initial Certificates offered and sold in reliance on Rule 144A
or to an Institutional Accredited Investor, or resold in reliance on Regulation
S and Rule 904 under the Securities Act, each shall be issued initially in the
form of one or more permanent global Certificates in registered form,
substantially in the form set forth as Exhibit A (respectively, the "144A Global
Certificate," the "IAI Global Certificate," and the "Regulation S Global
Certificate," each, a "Global Certificate"), duly executed and authenticated by
the Trustee as provided in Section 3.02 of the Basic Agreement. The Global
Certificates shall be registered in the name of Cede & Co., as nominee for DTC,
and deposited with the Trustee, as custodian for DTC. The aggregate principal
amount of the Global Certificates may from time to time be decreased by
adjustments made on the records of DTC or its nominee, or of the Trustee, as
custodian for DTC or its nominee, as hereinafter provided.

            (b) Initial Certificates offered and sold other than pursuant to
Rule 144A or pursuant to Regulation S or to Institutional Accredited Investors
shall be issued in the form of permanent certificated Certificates in registered
form, in substantially the form set forth as Exhibit A (the "Physical
Certificates"). All other Certificates shall be Global Certificates.

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

            Section 10.02 Restrictive Legends. (a) Subject to Section 10.03(a)
of this Trust Supplement, unless and until (i) an Initial Certificate or a
Private Exchange Certificate is sold under an effective Registration Statement,
(ii) an Initial Certificate is exchanged for an Exchange Certificate pursuant to
an effective Exchange Offer Registration Statement, (iii) an Initial Certificate
or a Private Exchange Certificate is sold pursuant to Rule 144, (iv) as
otherwise provided in the Private Placement Legend or (v) the Company and the
holder thereof otherwise agree, in each case as provided for in the Registration
Agreement, each Global Certificate and each Physical Certificate shall bear the
following legend (the "Private Placement Legend") on the face thereof:

      THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE U.S. SECURITIES ACT OF
1933, AS AMENDED (THE "SECURITIES ACT"), OR ANY STATE SECURITIES LAWS AND
ACCORDINGLY, THIS CERTIFICATE OR ANY INTEREST OR PARTICIPATION HEREIN MAY NOT BE
OFFERED OR SOLD WITHIN THE UNITED STATES OR TO, OR FOR THE ACCOUNT OR BENEFIT
OF, ANY PERSONS EXCEPT AS SET FORTH IN THE FOLLOWING SENTENCE. BY ITS
ACQUISITION HEREOF, THE HOLDER: (1) REPRESENTS THAT (A) IT IS A "QUALIFIED
INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT), (B) IT
IS AN INSTITUTIONAL "ACCREDITED INVESTOR" (AS DEFINED IN RULE 501 (a)(1), (2),
(3) OR (7) OF REGULATION D UNDER THE SECURITIES ACT) (AN "INSTITUTIONAL
ACCREDITED INVESTOR"), OR (C) IT IS OTHERWISE ACQUIRING THIS CERTIFICATE IN A
TRANSACTION EXEMPT FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT; (2)
AGREES THAT IT WILL NOT WITHIN TWO YEARS AFTER THE LATER OF THE ORIGINAL
ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS CERTIFICATE WAS
OWNED BY US AIRWAYS, INC., THE TRUSTEE OR ANY AFFILIATE OF ANY SUCH PERSON
RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE EXCEPT (A) TO US AIRWAYS, INC, (B)
TO A PERSON WHO THE HOLDER REASONABLY BELIEVES IS A QUALIFIED INSTITUTIONAL
BUYER IN COMPLIANCE WITH RULE 144A UNDER THE SECURITIES ACT, (C) TO AN

<PAGE>

INSTITUTIONAL ACCREDITED INVESTOR ACQUIRING $100,000 OR MORE AGGREGATE PRINCIPAL
AMOUNT OF SUCH CERTIFICATE THAT, PRIOR TO SUCH TRANSFER, FURNISHED TO THE
TRUSTEE A SIGNED LETTER CONTAINING CERTAIN REPRESENTATIONS AND AGREEMENTS
RELATING TO THE RESTRICTIONS ON TRANSFER OF THIS CERTIFICATE (THE FORM OF WHICH
LETTER CAN BE OBTAINED FROM THE TRUSTEE), (D) PURSUANT TO THE EXEMPTION FROM
REGISTRATION PROVIDED BY RULE 144 UNDER THE SECURITIES ACT (IF AVAILABLE), (E)
IN ACCORDANCE WITH ANOTHER EXEMPTION FROM THE SECURITIES ACT OR (F) PURSUANT TO
AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT; AND (3) AGREES
THAT IT WILL DELIVER TO EACH PERSON TO WHOM THIS CERTIFICATE IS TRANSFERRED
(OTHER THAN PURSUANT TO CLAUSES (2)(D) AND (2)(F) ABOVE) A NOTICE SUBSTANTIALLY
TO THE EFFECT OF THIS LEGEND. IN CONNECTION WITH ANY TRANSFER OF THIS
CERTIFICATE AS A RESTRICTED SECURITY WITHIN TWO YEARS AFTER THE LATER OF THE
ORIGINAL ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS CERTIFICATE
WAS HELD BY US AIRWAYS, INC., THE TRUSTEE OR ANY AFFILIATE OF ANY SUCH PERSONS
THE HOLDER MUST CHECK THE APPROPRIATE BOX SET FORTH ON THE TRANSFER NOTICE
RELATING TO THE MANNER OF SUCH TRANSFER AND SUBMIT THIS CERTIFICATE TO THE
TRUSTEE; PROVIDED THAT THE COMPANY AND THE TRUSTEE SHALL HAVE THE RIGHT PRIOR TO
ANY SUCH OFFER, SALE OR TRANSFER PURSUANT TO CLAUSE (2)(C) OR (2)(E) TO REQUIRE
THE DELIVERY OF AN OPINION OF COUNSEL, CERTIFICATION AND/OR OTHER INFORMATION
SATISFACTORY TO EACH OF THEM. THIS LEGEND WILL BE REMOVED UPON THE REQUEST OF
THE HOLDER AFTER THE RESALE RESTRICTIONS TERMINATE. THE CLASS C TRUST SUPPLEMENT
CONTAINS A PROVISION REQUIRING THE TRUSTEE TO REFUSE TO REGISTER ANY TRANSFER OF
THIS CERTIFICATE IN VIOLATION OF THE FOREGOING RESTRICTIONS.

            (b) Each Global Certificate of each class shall also bear the
following legend on the face thereof:

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

      TRANSFERS OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO TRANSFERS IN
      WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A SUCCESSOR THEREOF OR
      SUCH SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL
      CERTIFICATE SHALL BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE
      RESTRICTIONS SET FORTH IN SECTION 10.03 OF THE TRUST SUPPLEMENT NO.
      2000-3C.

            Section 10.03. Special Transfer Provisions. Unless and until (i) an
Initial Certificate or a Private Exchange Certificate is sold under an effective
Registration Statement, (ii) an Initial Certificate is exchanged for an Exchange
Certificate pursuant to an effective Exchange Offer Registration Statement,
(iii) an Initial Certificate or a Private Exchange Certificate is sold pursuant
to Rule 144, (iv) as otherwise provided in the Private Placement Legend or (v)
the Company and the holder thereof otherwise agree, the Registrar shall refuse
to register any exchange except in accordance with the following provisions:

            (a) Private Placement Legend. Upon the transfer, exchange or
replacement of Applicable Certificates not bearing the Private Placement Legend,
the Registrar shall deliver Applicable Certificates that do not bear the Private
Placement Legend. Upon the transfer, exchange or replacement of Applicable
Certificates bearing the Private Placement Legend, the Registrar shall deliver
only Applicable Certificates that bear the Private Placement Legend, except as
contemplated by Section 10.02.

<PAGE>

            (b) General. By its acceptance of any Applicable Certificate bearing
the Private Placement Legend, each Holder of such Applicable Certificate
acknowledges the restrictions on transfer of such Applicable Certificate set
forth in this Trust Supplement and agrees that it shall transfer such
Certificate only as provided in this Trust Supplement. The Registrar shall not
register a transfer of any Applicable Certificate unless such transfer complies
with the restrictions on transfer of such Certificate set forth in this Trust
Supplement. In connection with any transfer of Applicable Certificates, each
Certificateholder agrees by its acceptance of the Applicable Certificates to
furnish the Registrar or the Trustee such certifications, legal opinions or
other information as the Private Placement Legend requires to confirm that such
transfer is being made pursuant to an exemption from, or a transaction not
subject to, the registration requirements of the Securities Act.

            Until such time as no Applicable Certificates remain Outstanding,
the Registrar shall retain copies of all letters, notices and other written
communications received pursuant to this Section 10.03. The Trustee, if not the
Registrar at such time, shall have the right to inspect and make copies of all
such letters, notices or other written communications at any reasonable time
upon the giving of reasonable written notice to the Registrar.

            Transfers of the Applicable Certificates (and interests therein)
among different types of Global Certificates (including a Global Certificate not
containing a Private Placement Legend) and from Global Certificates to a
Physical Certificate and from Physical Certificates to Global Certificates shall
be made in accordance with the procedures set forth on Exhibit F hereto.

            IN WITNESS WHEREOF, the Company and the Trustee have caused this
Trust Supplement to be duly executed by their respective officers thereto duly
authorized, as of the day and year first written above.

                                  US AIRWAYS, INC.

                                  By:       /s/ Jeffery A. McDougle
                                      ----------------------------------------
                                      Name: Jeffery A. McDougle
                                      Title: Vice President and Treasurer

                                  STATE STREET BANK AND TRUST
                                  COMPANY OF CONNECTICUT,
                                  NATIONAL ASSOCIATION, as Trustee

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

<PAGE>

                                    EXHIBIT A

                               FORM OF CERTIFICATE

      THIS CERTIFICATE HAS NOT BEEN REGISTERED UNDER THE U.S. SECURITIES ACT OF
1933, AS AMENDED (THE "SECURITIES ACT"), OR ANY STATE SECURITIES LAWS AND
ACCORDINGLY, THIS CERTIFICATE OR ANY INTEREST OR PARTICIPATION HEREIN MAY NOT BE
OFFERED OR SOLD WITHIN THE UNITED STATES OR TO, OR FOR THE ACCOUNT OR BENEFIT
OF, ANY PERSONS EXCEPT AS SET FORTH IN THE FOLLOWING SENTENCE. BY ITS
ACQUISITION HEREOF, THE HOLDER: (1) REPRESENTS THAT (A) IT IS A "QUALIFIED
INSTITUTIONAL BUYER" (AS DEFINED IN RULE 144A UNDER THE SECURITIES ACT), (B) IT
IS AN INSTITUTIONAL "ACCREDITED INVESTOR" (AS DEFINED IN RULE 501 (a)(1), (2),
(3) OR (7) OF REGULATION D UNDER THE SECURITIES ACT) (AN "INSTITUTIONAL
ACCREDITED INVESTOR"), OR (C) IT IS OTHERWISE ACQUIRING THIS CERTIFICATE IN A
TRANSACTION EXEMPT FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT; (2)
AGREES THAT IT WILL NOT WITHIN TWO YEARS AFTER THE LATER OF THE ORIGINAL
ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS CERTIFICATE WAS
OWNED BY US AIRWAYS, INC., THE TRUSTEE OR ANY AFFILIATE OF ANY SUCH PERSON
RESELL OR OTHERWISE TRANSFER THIS CERTIFICATE EXCEPT (A) TO US AIRWAYS, INC.,
(B) TO A PERSON WHO THE HOLDER REASONABLY BELIEVES IS A QUALIFIED INSTITUTIONAL
BUYER IN COMPLIANCE WITH RULE 144A UNDER THE SECURITIES ACT, (C) TO AN
INSTITUTIONAL ACCREDITED INVESTOR ACQUIRING $100,000 OR MORE AGGREGATE PRINCIPAL
AMOUNT OF SUCH CERTIFICATE THAT, PRIOR TO SUCH TRANSFER, FURNISHED TO THE
TRUSTEE A SIGNED LETTER CONTAINING CERTAIN REPRESENTATIONS AND AGREEMENTS
RELATING TO THE RESTRICTIONS ON TRANSFER OF THIS CERTIFICATE (THE FORM OF WHICH
LETTER CAN BE OBTAINED FROM THE TRUSTEE), (D) PURSUANT TO THE EXEMPTION FROM
REGISTRATION PROVIDED BY RULE 144 UNDER THE SECURITIES ACT (IF AVAILABLE), (E)
IN ACCORDANCE WITH ANOTHER EXEMPTION FROM THE SECURITIES ACT OR (F) PURSUANT TO
AN EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT; AND (3) AGREES
THAT IT WILL DELIVER TO EACH PERSON TO WHOM THIS CERTIFICATE IS TRANSFERRED
(OTHER THAN PURSUANT TO CLAUSES (2)(D) AND (2)(F) ABOVE) A NOTICE SUBSTANTIALLY
TO THE EFFECT OF THIS LEGEND. IN CONNECTION WITH ANY TRANSFER OF THIS
CERTIFICATE AS A RESTRICTED SECURITY WITHIN TWO YEARS AFTER THE LATER OF THE
ORIGINAL ISSUANCE OF THIS CERTIFICATE OR THE LAST DATE ON WHICH THIS CERTIFICATE
WAS HELD BY US AIRWAYS, INC., THE TRUSTEE OR ANY AFFILIATE OF ANY SUCH PERSONS
THE HOLDER MUST CHECK THE APPROPRIATE BOX SET FORTH ON THE TRANSFER NOTICE
RELATING TO THE MANNER OF SUCH TRANSFER AND SUBMIT THIS CERTIFICATE TO THE
TRUSTEE; PROVIDED THAT THE COMPANY AND THE TRUSTEE SHALL HAVE THE RIGHT PRIOR TO
ANY SUCH OFFER, SALE OR TRANSFER PURSUANT TO CLAUSE (2)(C) OR (2)(E) TO REQUIRE
THE DELIVERY OF AN OPINION OF COUNSEL, CERTIFICATION AND/OR OTHER INFORMATION
SATISFACTORY TO EACH OF THEM. THIS LEGEND WILL BE REMOVED UPON THE REQUEST OF
THE HOLDER AFTER THE RESALE RESTRICTIONS TERMINATE. THE CLASS C TRUST SUPPLEMENT
CONTAINS A PROVISION REQUIRING THE TRUSTEE TO REFUSE TO REGISTER ANY TRANSFER OF
THIS CERTIFICATE IN VIOLATION OF THE FOREGOING RESTRICTIONS.

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

<PAGE>

      TRANSFERS OF THIS GLOBAL CERTIFICATE SHALL BE LIMITED TO TRANSFERS IN
WHOLE, BUT NOT IN PART, TO NOMINEES OF DTC OR TO A SUCCESSOR THEREOF OR SUCH
SUCCESSOR'S NOMINEE AND TRANSFERS OF PORTIONS OF THIS GLOBAL CERTIFICATE SHALL
BE LIMITED TO TRANSFERS MADE IN ACCORDANCE WITH THE RESTRICTIONS SET FORTH IN
SECTION 10.03 OF THE TRUST SUPPLEMENT NO. 2000-3C

                  US AIRWAYS SERIES 2000-3C PASS THROUGH TRUST

                        8.39% US Airways [Initial][Exchange]
                        Pass Through Certificate, Series
                        2000-3C

                        Final Expected Regular Distribution
                        Date: March 1, 2022 evidencing a
                        fractional undivided interest in a
                        trust, the property of which
                        includes certain equipment notes
                        each secured by Aircraft owned by or
                        leased to US Airways, Inc.

Certificate
No.1                    $157,054,000 Fractional Undivided Interest representing

--------
*This legend to appear on Book-Entry Certificates to be deposited with The
Depository Trust Company.

<PAGE>

                .0006367237% of the Trust per $1,000 face amount

            THIS CERTIFIES THAT Cede & Co., for value received, is the
registered owner of a $157,054,000 (ONE HUNDRED FIFTY SEVEN MILLION FIFTY FOUR
THOUSAND dollars) Fractional Undivided Interest in the US Airways Pass Through
Trust, Series 2000-3C (the "Trust") created by State Street Bank and Trust
Company of Connecticut, National Association, as trustee (the "Trustee"),
pursuant to a Pass Through Trust Agreement dated as of October 5, 2000 (the
"Basic Agreement"), between the Trustee and US Airways, Inc., a Delaware
corporation (the "Company"), as supplemented by Trust Supplement No. 2000-3C
thereto dated November 2, 2000, between the Trustee and the Company
(collectively, the "Agreement"), a summary of certain of the pertinent
provisions of which is set forth below. To the extent not otherwise defined
herein, the capitalized terms used herein have the meanings assigned to them in
the Agreement. This Certificate is one of the duly authorized Certificates
designated as "8.39% US Airways [Initial][Exchange] Pass Through Certificate,
Series 2000-3C" (herein called the "Certificates"). This Certificate is issued
under and is subject to the terms, provisions and conditions of the Agreement.
By virtue of its acceptance hereof, the Certificateholder of this Certificate
assents to and agrees to be bound by the provisions of the Agreement and the
Intercreditor Agreement. The property of the Trust includes certain Equipment
Notes and all rights of the Trust to receive any payments under the
Intercreditor Agreement and any Liquidity Facility (the "Trust Property"). Each
issue of the Equipment Notes is or will be secured by, among other things, a
security interest in aircraft leased to or owned by the Company.

            The Certificates represent Fractional Undivided Interests in the
Trust and the Trust Property, and have no rights, benefits or interest in
respect of any other separate trust established pursuant to the terms of the
Basic Agreement for any other series of certificates issued pursuant thereto.

            Subject to and in accordance with the terms of the Agreement and the
Intercreditor Agreement, from funds then available to the Trustee, there will be
distributed on each March 1 and September 1 (a "Regular Distribution Date"),
commencing on March 1, 2001, to the Person in whose name this Certificate is
registered at the close of business on the 15th day preceding the Regular
Distribution Date, an amount in respect of the Scheduled Payments on the
Equipment Notes due on such Regular Distribution Date, the receipt of which has
been confirmed by the Trustee, equal to the product of the percentage interest
in the Trust evidenced by this Certificate and an amount equal to the sum of
such Scheduled Payments. Subject to and in accordance with the terms of the
Agreement and the Intercreditor Agreement, in the event that Special Payments on
the Equipment Notes are received by the Trustee, from funds then available to
the Trustee, there shall be distributed on the applicable Special Distribution
Date, to the Person in whose name this Certificate is registered at the close of
business on the 15th day preceding the Special Distribution Date, an amount in
respect of such Special Payments on the Equipment Notes, the receipt of which
has been confirmed by the Trustee, equal to the product of the percentage
interest in the Trust evidenced by this Certificate and an amount equal to the
sum of such Special Payments so received. If a Regular Distribution Date or
Special Distribution Date is not a Business Day, distribution shall be made on
the immediately following Business Day with the same force and effect as if made
on such Regular Distribution Date or Special Distribution Date and no interest
shall accrue during the intervening period. The Trustee shall mail notice of
each Special Payment and the Special Distribution Date therefor to the
Certificateholder of this Certificate.

<PAGE>

            The Holder of this Certificate is entitled to the benefits of the
Registration Agreement, dated as of November 2, 2000, between the Company, the
Trustee and the Purchaser named therein (the "Registration Agreement"). If (i)
any Registration Statement required by the Registration Agreement is not (i)
filed with the Securities and Exchange Commission (the "Commission") on or prior
to the applicable filing deadline specified in the Registration Agreement, (ii)
any Registration Statement required by the Registration Agreement is not
declared effective by the Commission on or prior to the applicable effectiveness
deadline specified in the Registration Agreement, (iii) any Registered Exchange
Offer has not been consummated on or prior to the consummation deadline
specified in the Registration Agreement or (iv) any Registration Statement
required by the Registration Agreement is filed and declared effective but shall
thereafter cease to be effective or fail to be usable for its intended purpose
at any time prior to (a) in the case of an Exchange Offer Registration
Statement, the expiration of the respective Exchange Offer Registration Period
(as defined in the Registration Agreement) or (b) if a Shelf Registration
Statement (as defined in the Registration Agreement) is required to be filed
pursuant to the Registration Agreement, the expiration of the Shelf Registration
Period (as defined in the Registration Agreement), in each case without being
succeeded within two (2) days by a post-effective amendment to such Registration
Statement that cures such failure and that is itself declared effective within
five (5) days of filing such post-effective amendment to such Registration
Statement (each such event in clauses (i) through (iv), a "Registration
Default"), then the interest rate applicable to this Certificate shall be
increased as follows: during the first ninety (90)-day period immediately
following the occurrence of such Registration Default, such interest rate shall
be increased by 0.25% per annum from and including the first Business Day
following the date on which such Registration Default occurs to but excluding
the date such Registration Default is cured in accordance with the last sentence
of this paragraph. During Each subsequent ninety (90) day period during which
any Registration Default has occurred and is continuing, the interest rate
applicable to this Certificate shall increase by an additional 0.25% per annum
up to a maximum of 1.00% per annum. Notwithstanding the foregoing, (1) upon the
filing of the respective Registered Exchange Offer Registration Statement
(and/or, if applicable, the Shelf Registration Statement), in the case of (i)
above, (2) upon the effectiveness of the respective Registered Exchange Offer
Registration Statement (and/or, if applicable, the Shelf Registration Statement)
in the case of (ii) above, (3) upon consummation of the respective Registered
Exchange Offer in the case of (iii) above, or (4) upon the filing of a
post-effective amendment to the respective Registration Statement or any
additional Registration Statement that causes the respective Exchange Offer
Registration Statement (and/or, if applicable, the Shelf Registration Statement)
to again be declared effective or made usable in the case of (iv) above, the
existing Registration Default shall be deemed cured and the Securities that are
the subject of such Registration Statement as a result of such clause (i), (ii),
(iii) or (iv), as applicable, will again bear interest at 8.39% per annum, until
such time, if any, that another Registration Default occurs. Notwithstanding any
other provision of the Registration Agreement, the time periods in which a
Registration Default will be deemed to have occurred may be delayed or extended
in accordance with the provisions of the Registration Agreement.

            Subject to the terms of the Intercreditor Agreement, any incremental
interest due to a Holder of this Certificate will be passed through to such
Holder on each Regular Distribution Date in the manner provided for in the
Agreement, as more fully set forth in the Agreement and this Certificate.

<PAGE>

            Distributions on this Certificate will be made by the Trustee by
check mailed to the Person entitled thereto, without the presentation or
surrender of this Certificate or the making of any notation hereon, except that
with respect to Certificates registered on the Record Date in the name of a
Clearing Agency (or its nominee), such distribution shall be made by wire
transfer. Except as otherwise provided in the Agreement and notwithstanding the
above, the final distribution on this Certificate will be made after notice
mailed by the Trustee of the pendency of such distribution and only upon
presentation and surrender of this Certificate at the office or agency of the
Trustee specified in such notice.

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

            The Agreement permits, with certain exceptions therein provided, the
amendment thereof and the modification of the rights and obligations of the
Company and the rights of the Certificateholders under the Agreement at any time
by the Company and the Trustee with the consent of the Certificateholders
holding Certificates evidencing Fractional Undivided Interests aggregating not
less than a majority in interest in the Trust. Any such consent by the
Certificateholder of this Certificate shall be conclusive and binding on such
Certificateholder and upon all future Certificateholders of this Certificate and
of any Certificate issued upon the transfer hereof or in exchange hereof or in
lieu hereof whether or not notation of such consent is made upon this
Certificate. The Agreement also permits the amendment thereof, in certain
limited circumstances, without the consent of the Certificateholders of any of
the Certificates.

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

<PAGE>

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

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

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

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

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

            Any Person acquiring or accepting this Certificate or an interest
herein will, by such acquisition or acceptance, be deemed to have represented
and warranted that either: (i) the assets of an employee benefit plan subject to
Title I of the Employee Retirement Income Security Act of 1974, as amended
("ERISA"), or of a plan subject to Section 4975 of the Internal Revenue Code of
1986, as amended (the "Code"), have not been used to purchase this Certificate
or an interest herein or (ii) the purchase and holding of this Certificate or
interest herein are exempt from the prohibited transaction restrictions of ERISA
and the Code pursuant to one or more prohibited transaction statutory or
administrative exemptions.

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

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

<PAGE>

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

                                              US AIRWAYS PASS THROUGH TRUST
                                              2000-3C
                                              By: STATE STREET BANK AND TRUST
                                              COMPANY OF CONNECTICUT,
                                              NATIONAL ASSOCIATION, as Trustee

                                              By: ______________________________
                                              Title: ___________________________

Dated: ______________________________

<PAGE>

               FORM OF THE TRUSTEE'S CERTIFICATE OF AUTHENTICATION

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

                                           STATE STREET BANK AND TRUST
                                           COMPANY OF CONNECTICUT,
                                           NATIONAL ASSOCIATION, as Trustee

                                           By: _________________________________
                                                   Authorized Officer

<PAGE>

                                    EXHIBIT B

                             FORM OF TRANSFER NOTICE

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

Insert Taxpayer Identification No.

___________________

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

___________________

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

___________________

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

            In connection with any transfer of this Certificate occurring prior
to the date that is the earlier of the date of an effective Registration
Statement or ________, ____, the undersigned confirms that without utilizing any
general solicitation or general advertising that:

                                   [Check One]

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

                                       or

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

            If neither of the foregoing boxes is checked, the Trustee or other
Registrar shall not be obligated to register this Certificate in the name of any
Person other than the Holder hereof unless and until the conditions to any such
transfer of registration set forth herein and in Section 10.03 of the Trust
Supplement shall have been satisfied.

Date:                                [Name of Transferor]

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

Signature Guarantee: ___________________________

<PAGE>

                                    EXHIBIT C

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

                                                                          [Date]

State Street Bank and Trust Company
      of Connecticut, National Association
[Address]

      Re:   US Airways Pass Through Trust 2000-3C (the "Trust"), US Airways Pass
            Through Certificates, Series 2000-3C (the "Certificates")

Dear Sirs:

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

1.          the offer of the Certificates was not made to a person in the United
            States;

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

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

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

            In addition, if the sale is made during a restricted period and the
provisions of Rule 903(c)(3) or Rule 904(c)(1) of Regulation S are applicable
thereto, we confirm that such sale has been made in accordance with the
applicable provisions of Rule 903(c)(3) or Rule 904(c)(1), as the case may be.

            You and US Airways, Inc. are entitled to rely upon this letter and
are irrevocably authorized to produce this letter or a copy hereof to any
interested party in any administrative or legal proceedings or official inquiry
with respect to the matters covered hereby. Terms used in this certificate have
the meanings set forth in Regulation S.

                                               Very truly yours,
                                               [Name of Transferor]

                                                By: ____________________________
                                                    Authorized Signature

<PAGE>

                                    EXHIBIT D

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

                                                                          [Date]

State Street Bank and Trust Company of Connecticut,
       National Association
[Address]

      Re:   US Airways Pass Through Trust 2000-3C (the "Trust"), US Airways Pass
            Through Certificates, Series 2000-3C (the "Certificates")

Dear Sirs:

            In connection with our proposed purchase of $_________ aggregate
principal amount of the Certificates, we confirm that:

1.          We understand that any subsequent transfer of the Certificates is
            subject to certain restrictions and conditions set forth in the Pass
            Through Trust Agreement, dated as of __________, 2000, as
            supplemented by Trust Supplement No. 2000-3C, relating to the
            Certificates (the "Pass Through Trust Agreement") and the
            undersigned agrees to be bound by, and not to resell, pledge or
            otherwise transfer the Certificates except in compliance with, such
            restrictions and conditions and the Securities Act of 1933, as
            amended (the "Securities Act").

2.          We understand that the Certificates have not been registered under
            the Securities Act, and that the Certificates may not be offered or
            sold except as permitted in the following sentence. We agree, on our
            own behalf and on behalf of any accounts for which we are acting as
            hereinafter stated, that if we should sell any Certificate, we shall
            do so only (A) to US Airways, Inc., (B) to a person who the holder
            reasonably believes is a "qualified institutional buyer" in
            compliance with Rule 144A under the Securities Act, (C) to an
            institutional "accredited investor" acquiring $100,000 or more
            aggregate principal amount of such Certificate that, prior to such
            transfer, furnished to the Trustee a signed letter containing
            certain representations and agreements relating to the restrictions
            on transfer of this certificate (the form of which letter can be
            obtained from the Trustee), (D) pursuant to the exemption from
            registration provided by Rule 144 under the Securities Act (if
            available), (E) in accordance with another exemption from the
            Securities Act or (F) pursuant to an effective registration
            statement under the Securities Act; and we further agree to provide
            to any person purchasing any of the Certificates from us a notice
            advising such purchaser that resales of the Notes are restricted as
            stated herein. We further understand that the Certificates purchased
            by us shall bear a legend to the foregoing effect.

<PAGE>

3.          We understand that, in connection with any transfer of this
            Certificate as a restricted security within two years after the
            later of the original issuance of this Certificate or the last date
            on which this Certificate was held by US Airways, Inc., the Trustee,
            or any affiliate of any such persons, the holder must check the
            appropriate box set forth on the transfer notice attached to the
            Certificate relating to the manner of such transfer and submit this
            Certificate to the Trustee; provided that the Company and the
            Trustee shall have the right prior to any such offer, sale or
            transfer pursuant to clause (C) or (E) in paragraph 2 to require the
            delivery of an opinion of counsel, certification and/or other
            information satisfactory to each of them. We further understand that
            the Certificates purchased by us shall bear a legend to the
            foregoing effect.

4.          We are [an institutional "accredited investor" (as defined in Rule
            501(a)(1), (2), (3) or (7)]*/[a non-institutional "accredited
            investor" (as defined in Rule 501(a), (4), (5), (6) or (8)]** of
            Regulation D under the Securities Act) and have such knowledge and
            experience in financial and business matters as to be [, or have
            access to financial, legal, accounting and tax advisors and have
            consulted the same to the extent necessary for us to be,]** capable
            of evaluating the merits and risks of our investment in the
            Certificates and we and any accounts for which we are acting are
            each able to bear the economic risk of our or its investment.

-------
*        For institutional accredited investors only.

**       For non-institutional accredited investors only.

<PAGE>

5.          We are acquiring the Certificates purchased by us for our own
            account [or for one or more accounts (each of which is an
            institutional "accredited investor") as to each of which we exercise
            sole investment discretion.]*

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

                                               Very truly yours,
                                               [Name of Transferee]

                                               By: _____________________________
                                                   Authorized Signature

<PAGE>

                                    EXHIBIT E

                         [DTC Letter of Representations]

<PAGE>

                                    EXHIBIT F

                        OTHER SPECIAL TRANSFER PROVISIONS

      The following provisions shall supplement and, to the extent inconsistent
with, shall supercede and replace Sections 3.04 and 3.05 of the Basic Agreement.

            (a) Transfers other than to QIBs, IAIs, or pursuant to Regulation S.
The following provisions shall apply with respect to the registration of any
proposed transfer of an Applicable Certificate bearing, both before and after
the transfer, a Private Placement Legend (a "Restricted Certificate") other than
to any QIB, IAI which is not a QIB, or pursuant to Regulation S:

                  (i) The Registrar shall register the transfer of any such
      Restricted Certificate, if the proposed transferee has delivered to the
      Registrar a letter substantially in the form of Exhibit D hereto, and if
      (x) the proposed transferee agrees that it will not within two years after
      the later of the original issuance of this certificate or the last date on
      which this certificate was owned by US Airways, Inc., the Trustee or any
      affiliate of any such person resell or otherwise transfer this certificate
      except (a) to US Airways, Inc., (b) to a person who the transferee
      reasonably believes is a Qualified Institutional Buyer in compliance with
      Rule 144A under the Securities Act, (c) to an Institutional Accredited
      Investor acquiring $100,000 or more aggregate principal amount of such
      Certificate that, prior to such transfer, furnished to the Trustee a
      signed letter containing certain representations and agreements relating
      to the restrictions on transfer of this Certificate (the form of which
      letter substantially in the form of Exhibit D), (d) pursuant to the
      exemption from registration provided by Rule 144 under the Securities Act
      (if available), (e) in accordance with another exemption from the
      Securities Act or (f) pursuant to an effective registration statement
      under the Securities Act; (y) the proposed transferee agrees that it will
      deliver to each person to whom this certificate is transferred (other than
      pursuant to clauses (d) and (f) above) a notice substantially to the
      effect of this legend; and (z) the proposed transferor and transferee have
      delivered to the Registrar such other documents as are required by the
      Private Placement Legend.

                  (ii) If the proposed transferor is an Agent Member holding a
      beneficial interest in a Global Certificate, upon receipt by the Registrar
      of (x) the documents, if any, required by paragraph (i) and (y)
      instructions given in accordance with DTC's and the Registrar's
      procedures, the Registrar shall reflect on its books and records the date
      of the transfer and a decrease in the principal amount of such Global
      Certificate in an amount equal to the Fractional Undivided Interest
      represented by the beneficial interest in such Global Certificate to be
      transferred, and the Company shall execute, and the Trustee shall
      authenticate and deliver to the transferor or at its direction, one or
      more Physical Certificates of like class, tenor and amount, or an interest
      in a Restricted Certificate (other than a Rule 144A Global Certificate).

<PAGE>

            (b) Transfers to QIBs. The following provisions shall apply with
respect to the registration of any proposed transfer to a QIB:

                  (i) The Registrar shall register the transfer if (x) such
      transfer is being made by a proposed transferor who has checked the box
      provided for on the Form of Transfer Notice attached to the Initial
      Certificate or Private Exchange Certificate stating, or has otherwise
      advised the Trustee and the Registrar in writing, that the sale has been
      made in compliance with the provisions of Rule 144A to a transferee who
      the transferor reasonably believes is a QIB and has notified the
      transferee that the transferor is relying upon its foregoing
      representations in order to claim the exemption from registration provided
      by Rule 144A; and (y) the proposed transferor and transferee have
      delivered to the Registrar such other documents as are required by the
      Private Placement Legend.

                  (ii) If the Certificate to be transferred is a Physical
      Certificate, upon receipt by the Registrar of the documents referred to in
      clause (i) above and instructions given in accordance with DTC's and the
      Registrar's procedures therefor, the Registrar shall reflect on its books
      and records the date of such transfer and an increase in the Fractional
      Undivided Interest of the Rule 144A Global Certificate in an amount equal
      to the Fractional Undivided Interest of the Physical Certificates being
      transferred, and the Trustee shall cancel such Physical Certificates. If
      the proposed transfer is a transfer of a beneficial interest in one Global
      Certificate, the provisions of paragraph (e) below shall apply.

            (c) Transfers to IAIs. The following provisions shall apply with
respect to the registration of any proposed transfer of, or an interest in, a
Restricted Certificate (other than the IAI Global Certificate) to an IAI who is
not a QIB:

                  (i) The Registrar shall register the transfer if the proposed
      transferee has delivered to the Registrar a letter substantially in the
      form of Exhibit D and the proposed transferor and transferee have
      delivered to the Registrar such other documents as are required by the
      Private Placement Legend.

                  (ii) If the Certificate to be transferred is a Physical
      Certificate, upon receipt by the Registrar of the documents referred to in
      clause (i) above and instructions given in accordance with DTC's and the
      Registrar's procedures therefor, the Registrar shall reflect on its books
      and records the date of such transfer and an increase in the Fractional
      Undivided Interest of the IAI Global Certificate in an amount equal to the
      Fractional Undivided Interest of the Physical Certificates being
      transferred, and the Trustee shall cancel such Physical Certificates. If
      the proposed transfer is a transfer of a beneficial interest in one Global
      Certificate to a beneficial interest in another Global Certificate, the
      provisions of paragraph (e) below shall apply.

            (d) Transfers to Non-U.S. Persons. The following provisions shall
apply with respect to any registration of any transfer of an Initial Certificate
in accordance with Regulation S:

<PAGE>

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

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

                  (iii) Upon a sale or transfer after the expiration of the
      "restricted period" as defined in Regulation S of any Restricted
      Certificate acquired pursuant to Regulation S, such Certificate shall no
      longer bear the Private Placement Legend.

            (e) Transfers of and between Global Certificates. (i) Transfers of
any Global Certificate shall be limited to transfers of such Global Certificate
in whole, but not in part, to nominees of DTC, its successor or such successor's
nominees. Beneficial interests in the Global Certificate may be transferred in
accordance with the rules and procedures of DTC and the provisions of Section
9.03 and this Exhibit F. If the proposed transfer is a transfer of a beneficial
interest in one Global Certificate to a beneficial interest in another Global
Certificate, the Registrar shall reflect on its books and records the date of
such transfer and an increase in the principal amount of the Global Certificate
to which such interest is being transferred in an amount equal to the principal
amount of the interest to be so transferred, and the Registrar shall reflect on
its books and records the date of such transfer and a corresponding decrease in
the principal amount of the Global Certificate from which such interest is being
transferred.