Execution Copy


                      SECURITY TRUST AGREEMENT SUPPLEMENT


Bankers Trust Company, as Security Trustee
Four Albany Street
New York, New York 10006                                          March 15, 2000

Attention: Corporate Trust & Agency Services -
           Structured Finance


            Re: Security Trust Agreement, dated as of March 3, 1998
                ---------------------------------------------------


     Reference is made to the Security Trust Agreement, dated as of March 3,
1998 (the "Security Trust Agreement"), among MORGAN STANLEY AIRCRAFT FINANCE, a
Delaware business trust created under the Trust Agreement, as amended through
the date hereof, among MS Financing Inc., as depositor, Wilmington Trust
Company, as the Delaware Trustee, the Independent Trustees, the Alternate
Controlling Trustee and the Controlling Trustees party thereto, the ISSUER
SUBSIDIARIES party thereto, CABOT AIRCRAFT SERVICES LIMITED, a company
incorporated under the laws of Ireland, as the Administrative Agent, BANKERS
TRUST COMPANY, a New York banking corporation, as the Cash Manager,
INTERNATIONAL LEASE FINANCE CORPORATION, a corporation incorporated under the
laws of the State of California, as the Servicer, INTERNATIONAL LEASE FINANCE
CORPORATION, as credit facility provider under the Custody and Loan Agreement,
MORGAN STANLEY DEAN WITTER & CO., as credit facility provider under the Loan
Agreement, BANKERS TRUST COMPANY, not in its individual capacity (except as
otherwise provided in the Indenture), but solely in its capacity as trustee
under the Indenture, BANKERS TRUST COMPANY, not in its individual capacity, but
solely as the initial Reference Agent, and BANKERS TRUST COMPANY, not in its
individual capacity (except as otherwise provided pursuant to Sections 6.03(i)
and 6.03(ii) of the Security Trust Agreement), but solely as the initial
Security Trustee (the "Security Trustee"). Capitalized terms used herein and
not otherwise defined herein shall have the meanings assigned to them in the
Security Trust Agreement.

     The undersigned hereby agrees, as of the date first above written, to
become a Grantor under the Security Trust Agreement as if it were an original
party thereto and agrees that each reference in the Security Trust Agreement to
"Grantor" shall also mean and be a reference to the undersigned.

     The undersigned hereby assigns and pledges to the Security Trustee for its
benefit and the benefit of the Secured Parties, and hereby grants to the
Security Trustee for its benefit




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and the benefit of the Secured Parties a security interest in, all of its
right, title and interest in and to:

          (a) all of the following (collectively, the "Non-Trustee Account
     Collateral"):


               (i) all of the Non-Trustee Accounts (to the extent permitted by
          applicable law) in such Grantor's name, all funds held or required by
          the terms of the Indenture and any Guarantor Indenture to be held
          therein and all certificates and instruments, if any, from time to
          time representing or evidencing such Non- Trustee Accounts;

               (ii) all notes, certificates of deposit, deposit accounts,
          checks and other instruments from time to time hereafter delivered to
          or otherwise possessed by the Security Trustee for or on behalf of
          such Grantor in substitution for or in addition to any or all of the
          then existing Non-Trustee Account Collateral; and

               (iii) all interest, dividends, cash, instruments and other
          property from time to time received, receivable or otherwise
          distributed in respect of or in exchange for any or all of the then
          existing Non-Trustee Account Collateral;

          (b) all of the following (collectively, the "Cash Collateral"):

               (i) all funds of such Grantor held or required by the terms of
          the Indenture to be held in the Accounts and all certificates and
          instruments, if any, from time to time representing or evidencing
          such funds;

               (ii) all notes, certificates of deposit, deposit accounts,
          checks and other instruments from time to time hereafter delivered to
          or otherwise possessed by the Security Trustee for or on behalf of
          such Grantor in substitution for or in addition to any or all of the
          then existing Cash Collateral; and

               (iii) all interest, dividends, instruments and other property
          from time to time received, receivable or otherwise distributed in
          respect of or in exchange for any or all of the then existing Cash
          Collateral;

          (c) all "investment property" (as defined in Section 9-115(1)(f) of
     the UCC) of such Grantor, and all of the following (the "Investment
     Collateral"):

               (i) all Permitted Account Investments made or acquired from or
          with the proceeds of any Non-Trustee Account Collateral or Cash
          Collateral of such Grantor from time to time and all certificates and
          instruments, if any, from time to time representing or evidencing
          such Permitted Account Investments;




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               (ii) all notes, certificates of deposit, deposit accounts,
          checks and other instruments from time to time hereafter delivered to
          or otherwise possessed by the Security Trustee for or on behalf of
          such Grantor in substitution of or in addition to any or all of the
          then existing Investment Collateral; and

               (iii) all interest, dividends, instruments and other property
          from time to time received, receivable or otherwise distributed in
          respect of or in exchange for any or all of the then existing
          Investment Collateral; and

          (d) all of the following (the "Security Collateral"):

               (i) all shares of Stock from time to time acquired by such
          Grantor in any manner, and the certificates representing such shares
          and all dividends, cash, instruments and other property from time to
          time received, receivable or otherwise distributed in respect of or
          in exchange for any or all such shares; and

               (ii) all indebtedness from time to time owed to such Grantor by
          any MSAF Group Member and the instruments evidencing such
          indebtedness, and all interest, cash, instruments and other property
          from time to time received, receivable or otherwise distributed in
          respect of or in exchange for any or all of such indebtedness;

          (e) all of such Grantor's right, title and interest in all beneficial
     interests in any MSAF Group members from time to time acquired by such
     Grantor in any manner, all certificates, if any, from time to time
     representing all such beneficial interests and all distributions, cash,
     instruments and other property from time to time received, receivable or
     otherwise distributed in respect of or in exchange for any or all such
     beneficial interests (the "Beneficial Interest Collateral");

          (f) all of such Grantor's right, title and interest in and to all
     Leases to which such Grantor is or may from time to time be party and any
     leasing arrangements among MSAF Group Members with respect to such Leases
     (the "Assigned Leases"), including without limitation, (A) all rights of
     such Grantor to receive moneys due and to become due under or pursuant to
     such Assigned Leases, (B) all rights of such Grantor to receive proceeds
     of any Insurance, indemnity, warranty or guaranty with respect to such
     Assigned Leases, (C) claims of such Grantor for damages arising out of or
     for breach or default under such Assigned Leases and (D) the right of such
     Grantor to terminate such Assigned Leases, to perform thereunder and to
     compel performance and otherwise exercise all remedies thereunder, whether
     arising under such leases or by statute or at law or in equity; and




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          (g) all proceeds of any and all of the foregoing collateral
     (including, without limitation, proceeds that constitute property of the
     types described in subsections (a), (b), and (c), above).

     The undersigned hereby makes each representation and warranty set forth in
Section 2.07 of the Security Trust Agreement (as supplemented by the attached
Annexes) and hereby agrees to be bound as a Grantor by all of the terms and
provisions of the Security Trust Agreement. Each reference in the Security
Trust Agreement to the Security Collateral, the Assigned Leases and the
Beneficial Interest Collateral shall be construed to include a reference to the
corresponding Collateral hereunder.

     The undersigned hereby agrees, together with the Issuer, jointly and
severally to indemnify the Security Trustee, its officers, directors, employees
and agents in the manner set forth in Section 9.01 of the Security Trust
Agreement.

     Attached hereto are duly completed copies of Annex I and Annex II.

     This Security Trust Agreement Supplement shall be governed by, and
construed in accordance with, the laws of the State of New York.

                                          Very truly yours,

                                          MSA IV



                                          By: /s/ Brian J. Gill
                                             ----------------------------------
                                             Name: Brian J. Gill
                                             Title: Authorized Signatory


Acknowledged and agreed to
as of the date first above written:

BANKERS TRUST COMPANY,
  not in its individual capacity, but
  solely as the initial Security Trustee


By: /s/ Jenna Kaufman
   -------------------------------------
   Name:  Jenna Kaufman
   Title: Vice President





                                                                        ANNEX I
                                                  SECURITY AGREEMENT SUPPLEMENT


                                  TRADE NAMES

    None





                                                                       ANNEX II
                                                  SECURITY AGREEMENT SUPPLEMENT


                            CHIEF PLACE OF BUSINESS
                                      AND
                      CHIEF EXECUTIVE OR REGISTERED OFFICE


                                                       Chief Executive or
Name of Grantor           Place of Business            Registered Office
- ---------------           -----------------            -----------------
MSA IV              c/o Wilmington Trust Company    c/o Wilmington Trust Company
                    100 North Market Street         100 North Market Street
                    Rodney Square North             Rodney Square North
                    Wilmington                      Wilmington
                    Delaware 19890                  Delaware 19890
                    USA                             USA