EXHIBIT 10.21

                     [LETTERHEAD OF GMAC COMMERCIAL FINANCE]


                               SEPTEMBER 20, 2002



International  Airline  Support  Group,  Inc.
1954  Airport  Road,  Suite  200
Atlanta,  GA  30341
Attention:  Mr.  Alexius  A.  Dyer  III


Dear  Mr.  Dyer:

     Reference is hereby made to the Credit Agreement, dated as of September 30,
1996  (as  amended,  modified  or supplemented, the "Credit Agreement"), between
International  Airline  Support  Group,  Inc.  ("Borrower")  and GMAC Commercial
Credit  LLC  as  successor to BNY Financial Corporation ("Lender").  Capitalized
terms  not otherwise defined herein shall have the meanings given to them in the
Credit  Agreement.

     Borrower's  failure  to  make principal payments in the aggregate amount of
$216,383.33  on  August  31, 2002 constitutes Events of Default (the "Designated
Defaults").  Therefore, pursuant to the Credit Agreement, effective September 1,
2002, all Obligations shall bear interest at the default rate of interest as set
forth  in  Section  3.1(c)  of  the  Credit  Agreement.

     Effective  upon  receipt  by  Lender  of  this Letter Agreement executed by
Borrower,  Lender  hereby  agrees  that  Lender will forbear from exercising its
rights  and  remedies  with  respect  to the Designated Defaults, other than the
imposition  of  the  default  rate  as stated above and will continue to advance
Loans  to  the  Borrower in accordance with the terms of the Credit Agreement so
long  as (i) no Event of Default other than the Designated Defaults occurs, (ii)
Borrower  provides  Lender  weekly  cash flow budgets by Wednesday of each week,
(iii)  Borrower  continues  to  assist,  and  provide  information  to, Lender's
consultant,  Stout  Risius  Ross,  Inc. ("Stout"), so that Stout will be able to
deliver its report to Lender no later than September 20, 2002, (iv) Borrower and
Lender  have  entered  into  a  forbearance  agreement  on  terms and conditions
satisfactory  to  Lender  in its sole discretion no later than October 15, 2002,
and  (v)  Borrower reimburses Lender for all of Lender's reasonable professional
fees, costs and expenses; provided, however, that Borrower will not be obligated
                          --------  -------
to  reimburse  Lender for the fees and expenses of Stout to the extent that such
fees  and  expenses  exceed $15,000.  Lender further agrees that Lender will not
extend  the  scope  of  Stout's  engagement beyond the preparation of the report
referred  to in clause (iii) of the preceding sentence without the prior written
consent  of  Borrower,  which  consent  shall  not  be  unreasonably  withheld.

     By your signature below, Borrower hereby (i) releases, remises, acquits and
forever  discharges  Lender  and  Lender's  employees,  agents, representatives,
consultants,  attorneys,  fiduciaries,  officers,  directors,  partners,
predecessors,  successors  and  assigns,  subsidiary  corporations,  parent
corporations,  and related corporate divisions (all of the foregoing hereinafter
call  the  "Released  Parties"),  from any and all actions and causes of action,
judgments,  executions, suits, debts, claims, demands, liabilities, obligations,
damages and expenses of any and every character, known or unknown, direct and/or
indirect,  at  law or in equity, of whatsoever kind or nature, for or because of
any matter or things done, omitted or suffered to be done by any of the Released
Parties  prior  to  and  including  the date of execution hereof, and in any way
directly  or  indirectly  arising  out  of or in any way connected to the Credit
Agreement,  the  Security  Documents  and all documents executed or delivered in
connection  therewith  (collectively,  the  "Documents")  and  (ii)  waives  and
affirmatively  agrees  not  to  allege  or otherwise pursue any or all defenses,
affirmative  defenses, counterclaims, claims, causes of action, setoffs or other
rights  that  it  may have to contest (a) the Designated Defaults which could be
declared  by  Lender;  (b)  any  provision of the Credit Agreement, the Security
Documents or the Documents; (c) the security interest of Lender in any property,
whether  real  or  personal,  tangible  or  intangible,  or  any  right or other
interest, now or hereafter arising in connection with the Collateral; or (d) the
conduct  of  Lender in administering the financing arrangements between Borrower
and  Lender.

     Lender  hereby  reserves  all  other  rights  and remedies under the Credit
Agreement,  the  Security  Documents,  the  Documents  and  applicable  law, and
Lender's  election not to exercise any other such right or remedy at the present
time  shall  not  (a)  limit  in  any manner whatsoever Borrower's obligation to
comply  with,  and  Lender's right to insist on Borrower's compliance with, each
and  every  term  of  the  Credit  Agreement  and the Security Documents and (b)
constitute  a waiver of any Event of Default or any right or remedy available to
Lender  under the Credit Agreement, any Security Document or applicable law, and
Lender  herby  expressly  reserves  such  rights  with  respect  to  the  same.

     This  Letter  of Agreement shall be governed by and construed in accordance
with  the  laws  of  the  State of New York applied to contracts to be performed
wholly  within  the  State  of  New York.  Any judicial proceeding brought by or
against  Borrower  involving, directly or indirectly, any matter or claim in any
way  arising  out of, related to or connected with this Agreement or any related
agreement  may be brought in any court of competent jurisdiction in the State of
New  York,  County  of  New York, United States of America, and by execution and
delivery  of  this Agreement, Borrower accepts for itself and in connection with
its properties, generally and unconditionally, the non-exclusive jurisdiction of
the  aforesaid  courts,  and  irrevocably  agrees  to  be  bound by any judgment
rendered thereby in connection with this Agreement.  Nothing herein shall affect
the  right  to  serve  process in any manner permitted by law or shall limit the
right of Lender to bring proceedings against Borrower in the courts of any other
jurisdiction.  Borrower  waives  any  objection to jurisdiction and venue of any
action  instituted  hereunder  and shall not assert any defense based on lack of
jurisdiction  or  venue  or  based  upon  forum  non  conveniens.
                                          ----------------------

     EACH  OF  BORROWER AND LENDER HEREBY EXPRESSLY WAIVES ANY RIGHT TO TRIAL BY
JURY  OF  ANY  CLAIM,  DEMAND,  ACTION OR CAUSE OF ACTION (A) ARISING UNDER THIS
LETTER AGREEMENT, THE CREDIT AGREEMENT, THE SECURITY DOCUMENTS, THE DOCUMENTS OR
ANY  OTHER INSTRUMENT, DOCUMENT OR AGREEMENT EXECUTED OR DELIVERED IN CONNECTION
HEREWITH,  OR  (B)  IN  ANY  WAY  CONNECTED WITH OR RELATED OR INCIDENTAL TO THE
DEALINGS  OF  BORROWER  OR  LENDER  OR  ANY  OF THEM WITH RESPECT TO THIS LETTER
AGREEMENT,  THE  CREDIT  AGREEMENT, THE SECURITY DOCUMENTS, THE DOCUMENTS OR ANY
OTHER  INSTRUMENT,  DOCUMENT  OR  AGREEMENT  EXECUTED OR DELIVERED IN CONNECTION
HEREWITH, OR THE TRANSACTIONS RELATED HERETO OR THERETO IN EACH CASE WHETHER NOW
EXISTING  OR  HEREAFTER  ARISING,  AND  WHETHER  SOUNDING IN CONTRACT OR TORT OR
OTHERWISE  AND  EACH OF BORROWER AND LENDER HEREBY CONSENTS THAT ANY SUCH CLAIM,
DEMAND,  ACTION  OR  CAUSE  OF  ACTION SHALL BE DECIDED BY COURT TRIAL WITHOUT A
JURY,  AND  THAT EITHER BORROWER OR LENDER MAY FILE AN ORIGINAL COUNTERPART OR A
COPY OF THIS LETTER AGREEMENT WITH ANY COURT AS WRITTEN EVIDENCE OF THE CONSENTS
OF  BORROWER  AND  LENDER  TO  THE  WAIVER  OF THEIR RIGHT TO TRIAL BY JURY.  IN
ADDITION,  EACH  OF  BORROWER AND LENDER WAIVES THE RIGHT TO CLAIM OR RECOVER IN
ANY  SUIT,  ACTION OR PROCEEDING ANY DAMAGES OTHER THAN OR IN ADDITION TO ACTUAL
DAMAGES.

                              Very  truly  yours,


                              GMAC  COMMERCIAL  CREDIT  LLC



                              By:  /s/  Alexander  J.  Chobot
                                   --------------------------
     Name:     Alexander  J.  Chobot
     Title:     Vice  President


Accepted  and  Agreed  to:

INTERNATIONAL  AIRLINE  SUPPORT  GROUP,  INC.

By:  /s/  Alexis  A.  Dyer  III
     --------------------------
     Name:  Alexius  A.  Dyer  III
     Title:  Chairman,  President  and  Chief  Executive  Officer