SECURITY AGREEMENT
                               ------------------
               THIS SECURITY AGREEMENT ("Agreement") is made this 27th day
     of May, 1994, by and among AAI CORPORATION, a Maryland corporation
     ("AAI"), AAI ENGINEERING SUPPORT, INC., a Maryland corporation
     ("Engineering"), AAI MANUFACTURING ASSEMBLY, INC., a Maryland
     corporation ("Assembly"), AAI SYSTEMS MANAGEMENT, INC., a Maryland
     corporation ("Systems"), AAI MEDICAL CORPORATION, a Maryland
     corporation ("Medical"), SETI, INC., a Pennsylvania corporation
     ("Seti"), AAI/ACL TECHNOLOGIES, INC., a Maryland corporation
     ("AAI/ACL"), and AAI MICROFLITE SIMULATION INTERNATIONAL CORPORATION,
     a Maryland corporation ("AAI MICROFLITE"), jointly and severally (AAI,
     Engineering, Assembly, Systems, Medical, Seti, AAI/ACL and AAI
     MICROFLITE jointly and severally, individually and collectively,
     "Debtor"), and SIGNET BANK/MARYLAND ("Secured Party").

                                    RECITALS
                                    --------

               Reference is made to that certain Amended and Restated Loan
     Agreement dated August 11, 1992, as amended (the "Loan Agreement"), by
     and among Debtor and Secured Party pursuant to which Secured Party
     extended credit to Debtor in an original principal amount not to
     exceed Thirty Million Dollars ($30,000,000.00).  The "Termination
     Date" as defined in the Loan Agreement has occurred without extension
     by Secured Party, and all of the "Obligations" as therein defined have
     become due and payable.  Debtor has requested Secured Party to extend
     the Termination Date until August 20, 1994, and as a condition to
     consenting to such request Secured Party has, inter alia, required the
                                                   ----------
     execution hereof by Debtor.

               NOW, THEREFORE, in consideration of the mutual covenants
     contained herein, Debtor and Secured Party do hereby agree as follows:

               1.  CONSTRUCTION AND DEFINITION OF TERMS
                   ------------------------------------
                    Capitalized terms used herein without definition which
     are defined in the Loan Agreement shall have the meanings assigned to
     them in the Loan Agreement.  All terms used herein without definition
     which are not defined in the Loan Agreement and which are defined by
     the Maryland Uniform Commercial Code shall have the meanings assigned
     to them by the Maryland Uniform Commercial Code unless and to the
     extent varied by this Agreement.  Whenever the phrase "satisfactory to
     Secured Party" is used in this Agreement such phrase shall mean
     "satisfactory to















     NYFS11...:\95\78495\0001\7120\FRM80394.L40



     

     Secured Party in its sole discretion."  The use of any gender or the
     neuter herein shall also refer to the other gender or the neuter and
     the use of the plural shall also refer to the singular, and vice
     versa.  In addition to the terms defined elsewhere in this Agreement,
     unless the context otherwise requires, when used herein, the following
     terms shall have the following meanings:

                    "Collateral" shall mean all of Debtor's Receivables,
     all property and funds of Debtor, both now owned and hereafter
     acquired, now or hereafter in Secured Party's possession, all property
     and assets of Debtor in or on which Secured Party has, or may in the
     future acquire or be granted, a Lien, whether related or unrelated to
     this Agreement, whether or not now contemplated, whether or not any
     instrument or agreement relating thereto specifically refers to this
     Agreement, and all proceeds (cash and non-cash, including insurance
     proceeds), products, substitutions, renewals and replacements of all
     of the foregoing in any form whatsoever and all books, records and
     data processing materials in any form (including tapes, disks and the
     like) documenting, describing or in any way relating to any or all of
     the foregoing, whether in the possession of Debtor or any other
     Person.

                    "Event of Default" shall mean any of the events
     described in Section 6 hereof.

                    "Inter-Creditor Agreement" shall mean that certain
     Inter-Creditor Agreement made as of August 11, 1992, by and among
     Secured Party, Principal Mutual Life Insurance Company, The Travelers
     Insurance Company, The Travelers Indemnity Company of Rhode Island,
     AAI and UIC, as the same may hereafter be amended, supplemented or
     otherwise modified from time to time.

                    "Permitted Liens" shall mean (a) Liens of Secured
     Party, (b) Liens permitted pursuant to the Inter-Creditor Agreement,
     and (c) Liens specifically consented to by Secured Party in writing.

                    "Receivables" shall mean all of Debtor's present and
     future accounts, notes, instruments, documents, chattel paper, tax
     refunds, contract rights, general intangibles, goodwill, judgments,
     orders, awards and decrees in favor of Debtor, causes of action in
     favor of Debtor, all goods returned, repossessed, or stopped in
     transit the sale, lease or other disposition of which contributed to
     the creation of any account, instrument or chattel paper, all present
     and future rights of Debtor to the payment of money due or to become
     due to Debtor for





























     



     

     any reason whatsoever, whether or not such right to payment has been
     or is to be earned by any performance and howsoever such right to
     payment may be evidenced, whether by open account, instrument, note,
     draft, chattel paper, judgment, order, award, decree or otherwise, all
     rights which Debtor may at any time have, by law or agreement, against
     any account debtor, all rights which Debtor may at any time have, by
     law or agreement, against any other obligor obligated to make such
     payment and all rights and Liens which Debtor may at any time have, by
     law or agreement, against any property of any account debtor or
     against any property of any such other obligor; provided, however,
     that notwithstanding the foregoing, Receivables shall not include (a)
     any property now or hereafter abandoned or returned by the United
     States government which AAI is contractually obligated to deliver to
     Reflectone, Inc., or (b) any present or future rights of Debtor with
     respect to any patents, copyrights, franchises, trade names,
     trademarks, or computer software (collectively, "Excluded Intellectual
     Property") except to the extent such rights relate to (x) proceeds of
     such Excluded Intellectual Property which otherwise would fall within
     the foregoing definition of Receivables, or (y) computer software
     consisting of the books, records or data processing materials of
     Debtor documenting or describing the Receivables and/or any account
     debtor or other obligor of Debtor or in any way used or useful in the
     collection or enforcement of the Receivables.

               2.  SECURITY
                   --------
                    2.01  Security Interest.  As security for the payment
                          -----------------
     and performance of all of the Obligations, whether or not any
     instrument or agreement relating to any Obligation specifically refers
     to this Agreement or the security interest created hereunder, Debtor
     hereby assigns, pledges and grants to Secured Party a continuing
     security interest in the Collateral.  Secured Party's security
     interest shall continually exist until (a) all Obligations have been
     paid in full, and (b) there exists no commitment by Secured Party
     which could give rise to any Obligations, whether or not all
     Obligations shall at any time or from time to time be reduced to zero. 
     Debtor shall make notations, satisfactory to Secured Party, on its
     books and records disclosing the existence of Secured Party's security
     interest in the Collateral.  Secured Party shall have no liability or
     duty, either before or after the occurrence of an Event of Default
     hereunder, on account of loss of or damage to, or to collect or
     enforce any of its rights against, the Collateral, or to preserve any
     rights against account debtors or other parties with prior interests
     in the Collateral, the sole duty of Secured Party in this regard being
     to exercise reasonable




























     



     

     care with respect to tangible Collateral in its actual possession.

                    2.02  Covenants and Representations Concerning
                          ----------------------------------------
     Collateral.  With respect to all of the Collateral, Debtor covenants,
     ----------
     warrants and represents that:

                         (a)  No financing statement covering any of the
     Collateral is on file in any public office or land or financing
     records except for financing statements in favor of Secured Party and
     financing statements with respect to any Permitted Liens and Debtor is
     the legal and beneficial owner of all of the Collateral, free and
     clear of all Liens, except for Permitted Liens.

                         (b)  The security interest granted Secured Party
     here under shall constitute a first priority Lien upon the Collateral,
     except for any Permitted Liens.  Debtor will not, except in the
     ordinary course of business, transfer, discount, sell, grant or assign
     any interest in the Collateral nor, without Secured Party's prior
     written consent, permit any other Lien to be created or remain thereon
     except for Permitted Liens.

                         (c)  Debtor will maintain the Collateral in good
     order and condition, ordinary wear and tear excepted, and will use,
     operate and maintain the Collateral in compliance with all laws,
     regulations and ordinances and in compliance with all applicable
     insurance requirements and regulations.  Debtor will promptly notify
     Secured Party in writing of any litigation involving or affecting the
     Collateral which Debtor knows or has reason to believe is pending or
     threatened.  Debtor will promptly pay when due all taxes and all
     transportation, storage, warehousing and other such charges and fees
     affecting or arising out of or relating to the Collateral and shall
     defend the Collateral, at Debtor's expense, against all claims and
     demands of any Persons claiming any interest in the Collateral adverse
     to Debtor or Secured Party.

                         (d)  At all reasonable times Secured Party and its
     agents and designees may enter any business premises of Debtor and any
     other premises of Debtor and inspect the Collateral and all books and
     records of Debtor (in whatever form).

                         (e)  All books and records pertaining to the
     Collateral are located at York Road and Industry Lane, Cockeysville,
     Maryland 21030, at 11101 Gilroy Road, Cockeysville, Maryland 21030, at
     2801 Professional Parkway, Ocoee, Florida




























     



     

     34761, at 1505 East Warner Avenue, Santa Ana, California 92705-5419 or
     at 430 Stump Road, Montgomeryville, Pennsylvania 18936, and Debtor
     will not change the location(s) of such books and records without the
     prior written consent of Secured Party.

                         (f)  Debtor shall do, make, execute and deliver
     all such additional and further acts, things, deeds, assurances,
     instruments and documents as Secured Party may request to vest in and
     assure to Secured Party its rights hereunder or in any of the
     Collateral, including, without limitation, the execution and delivery
     of financing statements, financing statement amendments and/or
     continuation statements, and Debtor agrees to pay all taxes, fees and
     costs (including attorney's fees) paid or incurred by Secured Party in
     connection with the preparation and filing or recordation thereof.

                         (g)  A carbon, photographic or other reproduction
     of this Agreement or any financing statement signed by Debtor in
     connection with this Agreement shall be sufficient as a financing
     statement.

                         (h)  whenever required by Secured Party, Debtor
     shall promptly deliver to Secured Party, with all endorsements and/or
     assignments required by Secured Party, all instruments, chattel paper,
     guaranties and the like received by Debtor constituting, evidencing or
     relating to any of the Collateral or proceeds of any of the
     Collateral.

                         (i)  If any Receivable arises out of a contract
     with the United States of America or any State, county, municipality
     or any department, agency or instrumentality thereof, Debtor shall, if
     required by Secured Party, execute and deliver any agreements, notices
     and/or assignments and do such other things as may be satisfactory to
     Secured Party in order that all sums due and to become due to Debtor
     under such contract shall be duly assigned to Secured Party in
     accordance with the Federal Assignment of Claims Act (31 United States
     Code Section 1203; 41 United States Code Section 15) and/or any other
     applicable federal, State and local laws and regulations relating to the
     assignment of governmental obligations.

                         (j)  Debtor agrees that until the Obligations
     shall have been satisfied in full and this Agreement shall have been
     terminated, Debtor will not, without Secured Party's prior written
     consent, enter into any agreement (for example, a license agreement)
     which is inconsistent with Debtor's obligations under this Agreement
     and Debtor further agrees that it will not take any action, or permit
     any action to be taken by others subject to




























     



     

     its control, including licensees, or fail to take any action, which
     would materially adversely affect the validity or enforcement of the
     rights transferred to Secured Party under this Agreement.

               3.  REPRESENTATIONS AND WARRANTIES
                   ------------------------------
                    To induce Secured Party to enter into this Agreement,
     Debtor represents and warrants to Secured Party that:

                    3.01  Good Standing.  Debtor and each Subsidiary is a
                          -------------
     corporation duly organized, legally existing and in good standing
     under the laws of the State of its incorporation, has the power to own
     its property and to carry on its business and is duly qualified to do
     business and is in good standing in each jurisdiction in which the
     character of the properties owned by it therein or in which the
     transaction of its business makes such qualification necessary.

                    3.02  Authority.  Debtor has full power and authority
                          ---------
     to enter into this Agreement, to execute and deliver all documents and
     instruments required hereunder and to incur and perform the
     obligations provided for herein, all of which have been duly
     authorized by all necessary and proper corporate and other action, and
     no consent or approval of any Person, including, without limitation,
     stockholders of Debtor and any public authority or regulatory body,
     which has not been obtained is required as a condition to the validity
     or enforceability hereof or thereof.

                    3.03  Binding Agreements.  This Agreement has been duly
                          ------------------
     and properly executed by Debtor, constitutes the valid and legally
     binding obligation of Debtor and is fully enforceable against Debtor
     in accordance with its terms, subject only to laws affecting the
     rights of creditors generally and application of general principles of
     equity.

                    3.04  No Conflicting Agreements.  The execution,
                          -------------------------
     delivery and performance by Debtor of this Agreement will not (a)
     violate (i) any provision of law or any order, rule or regulation of
     any court or agency of government, (ii) any award of any arbitrator,
     (iii) the Charter or Bylaws of Debtor, or (iv) any indenture,
     contract, agreement, mortgage, deed of trust or other instrument to
     which Debtor is a party or by which Debtor or any of its property is
     bound, or (b) be in conflict with, result in a breach of or constitute
     (with due notice and/or lapse of time) a default under, any such
     award, indenture, contract, agreement, mortgage, deed of trust or
     other instrument, or result in the

























     



     

     creation or imposition of any Lien upon any of the property or assets
     of Debtor except for Liens created in favor of Secured Party under or
     pursuant to this Agreement.

                    3.05  Title to Properties.  Debtor has good and
                          -------------------
     marketable title to all of its properties and assets (including the
     Collateral) and all of the properties and assets of Debtor are free
     and clear of Liens, except for Permitted Liens.

                    3.06  Reaffirmation of Existing Representations and
                          ---------------------------------------------
     Warranties.  Each of the representations and warranties contained in
     ----------
     the Loan Agreement and the other Loan Documents is incorporated herein
     and restated as of the date hereof.

               4.  AFFIRMATIVE COVENANTS
                   ---------------------
                    Debtor covenants and agrees with Secured Party that,
     until (a) all Obligations have been paid in full and (b) there exists
     no commitment by Secured Party which could give rise to any
     Obligations, Debtor will:

                    4.01  Taxes.  Pay and discharge, and cause each
                          -----
     Subsidiary to pay and discharge, all taxes, assessments and
     governmental charges upon Debtor and each Subsidiary, its income and
     properties, prior to the date on which penalties attach thereto unless
     and to the extent only that the same are being diligently contested by
     Debtor or a Subsidiary, as the case may be, in good faith by
     appropriate proceedings, provided, however, that (a) Secured Party
     shall have been given reasonable prior written notice of intention to
     contest, (b)nonpayment of the same will not, in Secured Party's sole
     discretion, materially impair any of the Collateral or Secured Party's
     rights or remedies with respect thereto or the prospect for full and
     punctual payment of all of the Obligations, (c) Debtor or such
     Subsidiary at all times effectively stays or prevents any official or
     judicial sale of or action or filing against any of the Collateral by
     reason of nonpayment of the same and (d) Debtor or such Subsidiary
     establishes reasonable reserves for any liabilities being contested
     and for expenses arising out of such contest.

                    4.02  Extraordinary Loss.  Promptly notify Secured
                          ------------------
     Party in writing of any event causing extraordinary loss or
     depreciation of the value of Debtor's or any Subsidiary's assets
     (whether or not insured) and the facts with respect thereto.

                    4.03  Further Assurances and Corrective Instruments. 
                          ---------------------------------------------
     Promptly execute, acknowledge and deliver, or cause to be executed,
     acknowledged and delivered, to Secured Party from





















     



     

     time to time such supplements hereto and such financing statements and
     other instruments and documents as may be requested by Secured Party
     to protect and preserve the Collateral, Secured Party's security
     interest therein, perfection of Secured Party's security interest
     and/or Secured Party's rights and remedies hereunder and under the
     Loan Documents.

               5.  NEGATIVE COVENANTS
                   ------------------
                    Debtor covenants and agrees with Secured Party that,
     until (a) all Obligations have been paid in full, and (b) there exists
     no commitment by Secured Party which could give rise to any
     Obligations, Debtor will not, directly or indirectly, without Secured
     Party's prior written consent:

                    5.01  Dividends, Stock Redemptions.  Directly or
                          ----------------------------
     indirectly declare or pay any dividend on, or make any other
     distribution with respect to (whether by reduction of capital or
     otherwise), any shares of its capital stock, or purchase, redeem,
     retire or otherwise acquire for value any shares of its capital stock,
     except that a Subsidiary may pay dividends to Debtor.

                    5.02  Funded Debt.  Redeem, call for redemption,
                          -----------
     purchase or otherwise acquire or retire, directly or indirectly, or
     make any optional prepayment of principal on, any Funded Debt, or
     amend, alter or otherwise modify the provisions relating to any Funded
     Debt, if the effect of such amendment, alteration or other
     modification would or might be to accelerate such Funded Debt.  For
     purposes of this Subsection, "Funded Debt" shall include any
     obligation of Debtor to any Person other than Secured Party payable
     more than one year from the date of its creation which, under
     generally accepted accounting principles, is shown on the balance
     sheet as a liability (excluding reserves for deferred income taxes and
     other reserves to the extent that such reserves do not constitute an
     obligation).

               6.  EVENTS OF DEFAULT
                   -----------------
                    The occurrence of any one or more of the following
     events shall constitute an "Event of Default":

                    (a)  Any representation or warranty made herein, in any
     of the Loan Documents or in any statement, report, certificate,
     opinion, financial statement or other document furnished or to be
     furnished in connection with this Agreement or the Loan Documents
     shall be false or misleading in any material respect.


























     



     

                    (b)  Failure of Debtor or any other Person to observe
     or perform any warranty, covenant, condition or agreement to be
     observed or performed by Debtor or such other Person under this
     Agreement or any of the Loan Documents.

                    (c)  The occurrence of a default under or an "Event of
     Default" as defined in the Loan Agreement or any of the other Loan
     Documents.

               7.  RIGHTS AND REMEDIES
                   -------------------
                    7.01  Rights and Remedies of Secured Party.  Upon and
                          ------------------------------------
     after the occurrence of an Event of Default, Secured Party may,
     without notice or demand, exercise in any jurisdiction in which
     enforcement hereof is sought, the following rights and remedies, in
     addition to the rights and remedies available to Secured Party under
     the Loan Documents, the rights and remedies of a secured party under
     the Uniform Commercial Code and all other rights and remedies
     available to Secured Party under applicable law, all such rights and
     remedies being cumulative and enforceable alternatively, successively
     or concurrently:

                         (a)  Declare all of the Obligations to be
     immediately due and payable and the same shall thereupon become
     immediately due and payable without presentment, demand for payment,
     protest or notice of any kind, all of which are hereby expressly
     waived.

                         (b)  Institute any proceeding or proceedings to
     enforce the Obligations and any Liens of Secured Party.

                         (c)  Take possession of the Collateral, and for
     that purpose, so far as Debtor may give authority therefor, enter upon
     any premises on which the Collateral or any part thereof may be
     situated and remove the same therefrom without any liability for suit,
     action or other proceeding, DEBTOR HEREBY WAIVING ANY AND ALL RIGHTS
     TO PRIOR NOTICE AND TO JUDICIAL HEARING WITH RESPECT TO REPOSSESSION
     OF COLLATERAL, and require Debtor, at Debtor's expense, to assemble
     and deliver the Collateral to such place or places as Secured Party
     may designate.

                         (d)  Operate, manage and control the Collateral
     (including use of the Collateral and any other property or assets of
     Debtor in order to continue or complete performance of Debtor's
     obligations under any contracts of Debtor), or permit the Collateral
     or any portion thereof to remain idle or store the same, and collect
     all rents and revenues


























     



     

     therefrom and sell or otherwise dispose of any or all of the
     Collateral upon such terms and under such conditions as Secured Party,
     in its sole discretion, may determine, and purchase or acquire any of
     the Collateral at any such sale or other disposition, all to the
     extent permitted by applicable law.

                         (e)  With respect to any accounts, notes,
     instruments, chattel paper, tax refunds, contract rights, general
     intangibles or other debts or liabilities payable to Debtor securing
     the Obligations, notify any account debtors and other obligors thereon
     to make payments thereon directly to Secured Party, take control of
     the cash and non-cash proceeds thereof, demand, collect, sue for and
     receive any money or property at any time due, payable or receivable
     on account thereof, compromise and settle with any Person liable
     thereon, and extend the time of payment or otherwise change the terms
     thereof, without incurring liability or responsibility therefor to
     Debtor or any guarantor of any of the Obligations.

                         (f)  Cease making advances under any other
     commitments or credit accommodations of Secured Party to Debtor and
     stop and retract the making of any advance hereunder or thereunder
     which may have been requested by Debtor.

                    7.02  Power of Attorney.  Effective upon the occurrence
                          -----------------
     of an Event of Default, Debtor hereby designates and appoints Secured
     Party and its designees as attorney-in-fact of Debtor, irrevocably and
     with power of substitution, with authority to receive, open and
     dispose of all mail addressed to Debtor; to notify the postal
     authorities to change the address for delivery of mail addressed to
     Debtor to such other address as Secured Party designates; to endorse
     Debtor's name on any notes, acceptances, checks, drafts, money orders,
     instruments or other evidences of payment or proceeds of the
     Collateral that may come into Secured Party's possession; to sign
     Debtor's name on any invoices, documents, drafts against and notices
     to account debtors or other obligors of Debtor and requests for
     verification of accounts; to execute proofs of claim and loss; to
     execute any endorsements, assignments or other instruments of
     conveyance or transfer; to adjust and compromise any claims under
     insurance policies; to execute releases; and to perform all other acts
     necessary and advisable, in Secured Party's sole discretion, to carry
     out and enforce this Agreement and the Loan Documents.  All acts of
     said attorney or designee are hereby ratified and approved by Debtor
     and said attorney or designee shall not be liable for any acts of
     commission or omission nor for any error of judgment or mistake of
     fact or law.  This power of attorney is coupled with an interest and
     is irrevocable so long as any of the



























     



     

     Obligations remain unpaid or unperformed or there exists any
     commitment by Secured Party which could give rise to any Obligations.

                    7.03  Notice of Disposition of Collateral.  It is
                          -----------------------------------
     mutually agreed that commercial reasonableness and good faith require
     Secured Party to give Debtor no more than 5 Business Days prior
     written notice of the time and place of any public disposition of
     Collateral or of the time after which any private disposition or any
     other intended disposition is to be made.

                    7.04  Costs and Expenses.  Debtor agrees to pay to
                          ------------------
     Secured Party on demand the amount of all expenses, including
     attorney's fees and court costs paid or incurred by Secured Party in
     exercising or enforcing or consulting with counsel concerning any of
     its rights hereunder, under the Loan Documents or under applicable
     law, together with interest on all such expenses paid by Secured Party
     at the highest rate and calculated in the manner provided in the Note;
     provided, however, that if such Note shall have been satisfied in full
     and no commitment by Secured Party to extend additional credit to
     Debtor under the Loan Agreement or any of the other Loan Documents
     shall exist, interest shall accrue at the highest rate and calculated
     in the manner provided in the Loan Documents.  The provisions of this
     Subsection shall survive the termination of this Agreement and Secured
     Party's security interest hereunder and the payment of all other
     Obligations.

               8.  MISCELLANEOUS
                   -------------
                    8.01  Performance for Debtor.  Debtor agrees and hereby
                          ----------------------
     authorizes that Secured Party may, in Secured Party's sole discretion,
     but Secured Party shall not be obligated to, whether or not an Event
     of Default shall have occurred, advance funds on behalf of Debtor,
     without prior notice to Debtor, in order to insure Debtor's compliance
     with any covenant, warranty, representation or agreement of Debtor
     made in or pursuant to this Agreement or any of the Loan Documents, to
     continue or complete, or cause to be continued or completed,
     performance of Debtor's obligations under any contracts of Debtor, to
     cover overdrafts in any checking or other accounts of Debtor at
     Secured Party or to preserve or protect any right or interest of
     Secured Party in the Collateral or under or pursuant to this Agreement
     or any of the Loan Documents, including, without limitation, the
     payment of any insurance premiums or taxes and the satisfaction or
     discharge of any judgment or any Lien upon the Collateral or other
     property or assets of Debtor; provided, however, that the making of
     any such advance by Secured Party shall not constitute a waiver by
     Secured

























     



     

     Party of any Event of Default with respect to which such advance is
     made nor relieve Debtor of any such Event of Default.  Debtor shall
     pay to Secured Party upon demand all advances made by Secured Party
     under this Subsection 8.01 with interest thereon at the highest rate
     and calculated in the manner provided in the Note; provided, however,
     that if such Note shall have been satisfied in full and no commitment
     by Secured Party to extend additional credit to Secured Party under
     the Loan Agreement or any of the other Loan Documents shall exist,
     interest shall accrue at the highest rate and calculated in the manner
     provided in the Loan Documents.  All such advances shall be deemed to
     be included in the Obligations and secured by the security interest
     granted Secured Party hereunder; provided, however, that the
     provisions of this Subsection shall survive the termination of this
     Agreement and Secured Party's security interest hereunder and the
     payment of all other Obligations.

                    8.02  Expenses.  Debtor agrees to pay to Secured Party
                          --------
     on demand the amount of all expenses paid or incurred by Secured Party
     (including the fees and expenses of its counsel) in connection with
     the preparation of all written commitments of Secured Party antedating
     this Agreement, this Agreement and the Loan Documents and all
     documents and instruments referred to herein.  Debtor further agrees
     to pay all expenses in connection with the filing or recordation of
     all financing statements and instruments as may be required by Secured
     Party at the time of, or subsequent to, the execution of this
     Agreement, including, without limitation, all documentary stamps,
     recordation and transfer taxes and other costs and taxes incident to
     recordation of any document or instrument in connection herewith and,
     if any such expenses shall be paid or incurred by Secured Party, to
     pay to Secured Party upon its demand the amount of such expenses. 
     Debtor agrees to save harmless and indemnify Secured Party from and
     against any liability resulting from the failure to pay any required
     documentary stamps, recordation and transfer taxes, recording costs,
     or any other expenses in connection with this Agreement.  The
     provisions of this Subsection shall survive the termination of this
     Agreement and Secured Party's security interest hereunder and the
     payment of all other Obligations.

                    8.03  Applications of Collateral.  Except as may be
                          --------------------------
     otherwise specifically provided in this Agreement, all Collateral and
     proceeds of Collateral coming into Secured Party's possession may be
     applied by Secured Party to any of the Obligations, whether matured or
     unmatured, as Secured Party shall determine in its sole discretion.





























     



     

                    8.04  Waivers by Debtor.  Debtor hereby waives, to the
                          -----------------
     extent the same may be waived under applicable law: (a) notice of
     acceptance of this Agreement; (b) all claims, causes of action and
     rights of Debtor against Secured Party on account of actions taken or
     not taken by Secured Party in the exercise of Secured Party's rights
     or remedies hereunder, under the Loan Documents or under applicable
     law; (c) all claims of Debtor for failure of Secured Party to comply
     with any requirement of applicable law relating to enforcement of
     Secured Party's rights or remedies hereunder, under the Loan Documents
     or under applicable law; (d) all rights of redemption of Debtor with
     respect to the Collateral; (e) in the event Secured Party seeks to
     repossess any or all of the Collateral by judicial proceedings, any
     bond(s) or demand(s) for possession which otherwise may be necessary
     or required; (f) presentment, demand for payment, protest and notice
     of non-payment and all exemptions; (g) any and all other notices or
     demands which by applicable law must be given to or made upon Debtor
     by Secured Party; (h) settlement, compromise or release of the
     obligations of any Person primarily or secondarily liable upon any of
     the Obligations; (i) trial by jury in any action or proceeding of any
     kind or nature in connection with any of the Obligations, this
     Agreement or any of the Loan Documents; and (j) substitution,
     impairment, exchange or release of any collateral security for any of
     the Obligations.  Debtor agrees that Secured Party may exercise any or
     all of its rights and/or remedies hereunder, under the Loan Documents
     and under applicable law without resorting to and without regard to
     any collateral security or sources of liability with respect to any of
     the Obligations.

                    8.05  Waivers by Secured Party.  Neither any failure
                          ------------------------
     nor any delay on the part of Secured Party in exercising any right,
     power or remedy hereunder, under any of the Loan Documents or under
     applicable law shall operate as a waiver thereof, nor shall a single
     or partial exercise thereof preclude any other or further exercise
     thereof or the exercise of any other right, power or remedy.

                    8.06  Modifications.  No modification or waiver of any
                          -------------
     provision of this Agreement or any of the Loan Documents, and no
     consent by Secured Party to any departure by Debtor therefrom, shall
     in any event be effective unless the same shall be in writing, and
     then such waiver or consent shall be effective only in the specific
     instance and for the purpose for which given.  No notice to or demand
     upon Debtor in any case shall entitle Debtor to any other or further
     notice or demand in the same, similar or other circumstances.




























     



     

                    8.07  Notices.  Any notice or other communication in
                          -------
     connection with this Agreement shall be provided in the manner
     specified in the Loan Agreement.

                    8.08  Confession of Judgment.  Debtor hereby authorizes
                          ----------------------
     any clerk of court or any attorney-at-law to appear for Debtor before
     any court, having jurisdiction, within the United States or elsewhere,
     and, after one or more complaints filed, confess judgment against
     Debtor as of any time after any of the Obligations are due (whether by
     demand, stated maturity, acceleration or otherwise) for the unpaid
     balance of the Obligations, including principal, interest, fees, late
     charges, court costs and expenses, together with attorneys' fees equal
     to fifteen percent (15%) of the amount of such Obligations, for
     collection and release of all errors, and without stay of execution,
     and inquisition and extension upon any levy on real estate is hereby
     waived and condemnation agreed to, and the exemption of personal
     property from levy and sale is also hereby expressly waived, and no
     benefit of exemption shall be claimed under any exemption law now in
     force or which may be hereafter adopted.  The foregoing authorities
     and powers to confess judgment shall not be exhausted by one or more
     exercises of any of them or by any imperfect exercise of any of them,
     shall not be extinguished by any judgment entered because of any of
     them and may be exercised before, during or after sale, liquidation or
     other disposition by Secured Party of any property directly or
     indirectly securing any of the Obligations or exercise or enforcement
     by Secured Party of any other right or remedy of Secured Party with
     respect to the Obligations.  Debtor agrees that any agreements of
     Debtor contained in this Agreement or any of the Other Agreements to
     pay any costs or expenses, including attorneys' fees and expenses,
     paid or incurred by Secured Party shall not be merged into, or
     otherwise impaired by, any such judgment by confession, but Secured
     Party shall not be entitled to recover on account of such costs or
     expenses any amount in excess of the greater of (a) such costs or
     expenses included in any judgments by confession (without
     duplication), or (b) such costs or expenses actually paid or incurred
     by Secured Party.

                    8.09  Survival; Successors and Assigns.  All covenants,
                          --------------------------------
     agreements, representations and warranties made herein and in the Loan
     Documents shall survive the execution and delivery hereof and thereof,
     and shall continue in full force and effect until all Obligations have
     been paid in full and there exists no commitment by Secured Party
     which could give rise to any Obligations.  Whenever in this Agreement
     any of the parties hereto is referred to, such reference shall be
     deemed to include the successors and assigns of such party.  All
     covenants,

























     



     

     agreements, representations and warranties by or on behalf of Debtor
     which are contained in this Agreement and the Loan Documents shall
     inure to the benefit of Secured Party, its successors and assigns. 
     Debtor may not assign this Agreement or any of its rights hereunder
     without the prior written consent of Secured Party.  Secured Party may
     at any time, in its discretion, assign, transfer or pledge to any
     person, or grant to any person a security interest in, the
     Obligations, this Agreement, any of the Other Agreements or any of its
     rights hereunder or thereunder.  In addition, Secured Party may sell,
     in such amounts, upon such terms and to such persons as Secured Party
     may determine, participations in its interests in the Obligations
     and/or under this Agreement and/or any of the Other Agreements.  In
     the case of each such assignment, transfer, pledge, grant or sale,
     Secured Party may from time to time provide to the assignee,
     transferee, pledgee, secured party or participant, any information and
     documents (or copies thereof) relating to this Agreement and the Other
     Agreements and related transactions, and relating to the business,
     assets, operations, business prospects or financial condition of
     Debtor.

                    8.10  Merger and Integration.  This Agreement and the
                          ----------------------
     attached Schedule(s) contain the entire agreement of the parties
     hereto with respect to the matters covered and the transactions
     contemplated hereby, and no other agreement, statement or promise made
     by any party hereto, or by any employee, officer, agent or attorney of
     any party hereto, which is not contained herein, shall be valid or
     binding.

                    8.11  Counterparts.  This Agreement may be executed in
                          ------------
     any number of counterparts and by different parties hereto on separate
     counterparts, each of which, when so executed and delivered, shall be
     an original, but all such counterparts shall together constitute one
     and the same instrument.

                    8.12  Headings.  The headings and sub-headings
                          --------
     contained in the titling of this Agreement are intended to be used for
     convenience only and shall not be used or deemed to limit or diminish
     any of the provisions hereof.

                    8.13  Recitals.  The Recitals hereto are hereby
                          --------
     incorporated into and made a part of this Agreement.

                    8.14  Loan Document.  This Agreement is one of the Loan
                          -------------
     Documents.

























     



     

               IN WITNESS WHEREOF, the parties hereto have executed or
     caused to be executed this Agreement under seal as of the date first
     above written.

     WITNESS/ATTEST:                    AAI CORPORATION

                                        By:Robert W. Worthing(SEAL)
     --------------------                  ------------------
                                        Name:                     
                                             ---------------------
                                        Title:                    
                                              --------------------

                                        AAI ENGINEERING SUPPORT, INC.

                                        By:Robert W. Worthing(SEAL)
     --------------------                  ------------------
                                        Name:                     
                                             ---------------------
                                        Title:                    
                                              --------------------

                                        AAI MANUFACTURING ASSEMBLY,

                                        By: Robert W. Worthing (SEAL)
     --------------------                   ------------------
                                        Name:                     
                                             ---------------------
                                        Title:                    
                                              --------------------

                                        AAI SYSTEMS MANAGEMENT, INC.

                                        By: Robert W. Worthing(SEAL)
     --------------------                   ------------------
                                        Name:                     
                                             ---------------------
                                        Title:                    
                                              --------------------

                                        AAI MEDICAL CORPORATION

                                        By:Robert W. Worthing(SEAL)
     --------------------                  ------------------
                                        Name:                     
                                             ---------------------
                                        Title:                    
                                              --------------------

                                        SETI, INC.

                                        By:Robert W. Worthing(SEAL)
     --------------------                  ------------------
                                        Name:                     
                                             ---------------------
                                        Title:                    
                                              --------------------

















     



     

                                        AAI/ACL TECHNOLOGIES, INC.

                                        By:Robert W. Worthing(SEAL)
     --------------------                  ------------------
                                        Name:                     
                                             ---------------------
                                        Title:                    
                                              --------------------


                                        AAI MICROFLITE SIMULATION
                                        INTERNATIONAL CORPORATION

                                        By:Robert W. Worthing(SEAL)
     --------------------                  ------------------
                                        Name:                     
                                             ---------------------
                                        Title:                    
                                              --------------------
                                                       DEBTOR






















































     



     

                                        SIGNET BANK/MARYLAND


                                        By:David A. Bauereis(SEAL)
     -------------------------             -----------------
                                           David A. Bauereis
                                           Vice President

                                                  SECURED PARTY



     STATE OF MARYLAND, TO WIT:

               I HEREBY CERTIFY that on this ____ day of _________, 1994,
     before me, the subscriber, a Notary Public of said State, personally
     appeared Paul J. Michaud, who acknowledged himself to be (1) the Vice
     President, Chief Financial Officer and Treasurer of each of AAI
     Corporation, AAI Engineering Support, Inc., AAI Manufacturing
     Assembly, Inc., AAI Systems Management, Inc., Seti, Inc. and AAI/ACL
     Technologies, Inc., (2) the Vice President and Secretary of AAI
     Medical Corporation, and (3) the Vice President and Chief Financial
     Officer of AAI Microflite Simulation International Corporation, and
     that he, as such, being authorized so to do, executed the foregoing
     instrument for the purposes therein contained.

               IN WITNESS WHEREOF, I hereunto set my hand and official
     seal.

                                                                      
                                             -------------------------
                                             Notary Public


     My Commission expires:
                           
     ----------------------