PLEDGE AND SECURITY AGREEMENT


               THIS AGREEMENT is made as of the ________ day of
     _______________, 1994, by and between FIRST FIDELITY BANK, NATIONAL
     ASSOCIATION, as Agent (in such capacity, "Secured Party") for the
     Lenders, the Issuing Bank and the Noteholders (as those terms are
     hereinafter defined), and AAI CORPORATION, a Maryland corporation
     ("Debtor").


              SECTION 1.  CONSTRUCTION OF AGREEMENT AND DEFINITIONS


     Unless the context otherwise requires, all of the terms used herein
     without definition which are defined by the Maryland Uniform
     Commercial Code shall have the meanings assigned to them by the
     Maryland Uniform Commercial Code except to the extent varied by this
     Agreement.  Unless the context otherwise requires, all capitalized
     terms hereinbefore or hereinafter used in this Agreement without
     definition shall have the meanings assigned to such terms in the
     Credit Agreement.  The phrases "satisfactory to Secured Party,"
     "acceptable to Secured Party" and similar phrases shall mean
     satisfactory or acceptable to Secured Party, in Secured Party's
     discretion exercised in good faith.  The use of the singular herein
     shall also refer to the plural and vice versa, and the use herein of
     any gender, including the neuter, shall also refer to each of the
     other genders, including the neuter.  The captions and headings
     contained in this Agreement are for convenience of reference only and
     shall not affect the meaning, or the construction or interpretation,
     of this Agreement.  In addition to terms defined elsewhere in this
     Agreement, the following terms shall have the following meanings when
     used herein:

               "CARSHELL" shall mean AAI California Carshell, Inc., a
     Maryland corporation.

               "CARSHELL SECURITIES" shall mean the shares of capital stock
     of Carshell identified on the Securities Exhibit attached to this
     Agreement and incorporated by reference into this Agreement, and all
     other shares of capital stock and other securities of Carshell, now
     owned or hereafter acquired by Debtor.

               "COLLATERAL" shall mean:  (a) the Securities Collateral; and
     (b) all of Debtor's present and future books and records in any form
     relating to the Securities Collateral, in or on any media, including
     data processing materials in any form (including software, tapes,
     disks and the like), whether in the possession of Debtor or any other
     person.

               "CREDIT AGREEMENT" shall mean, as the same may be waived,
     amended, modified, extended, renewed, supplemented or replaced from
     time to time, that certain Credit Agreement of even date herewith
     among Debtor, Secured Party, Lenders and Issuing Bank.







               "DEBTOR NOTICE ADDRESS" shall mean York Road and Industry
     Lane, Hunt Valley, Maryland 21030.

               "ENGINEERING" shall mean AAI Engineering Support Inc., a
     Maryland corporation.

               "ENGINEERING SECURITIES" shall mean the shares of capital
     stock of Engineering identified on the Securities Exhibit attached to
     this Agreement and incorporated by reference into this Agreement, and
     all other shares of capital stock of Engineering and other securities
     of Engineering, now owned or hereafter acquired by Debtor.

               "EVENT OF DEFAULT" shall mean an "Event of Default," as
     defined in the Credit Agreement, or an "Event of Default," as defined
     in the Note Purchase Agreement.

               "GOOD FAITH" shall mean, with respect to a determination,
     request or other action to be made or taken by Secured Party "in good
     faith," that Secured Party shall make or take such determination,
     request or other action honestly and not maliciously.

               "INTERCREDITOR AGREEMENT" shall mean, as the same may be
     amended, modified, extended, renewed, supplemented or replaced from
     time to time, that certain Intercreditor Agreement of even date
     herewith among Secured Party, Lenders, Issuing Bank and Noteholders.

               "INTERNATIONAL" shall mean AAI International, Inc., a
     Delaware corporation.

               "INTERNATIONAL SECURITIES" shall mean the shares of capital
     stock of International identified on the Securities Exhibit attached
     to this Agreement and incorporated by reference into this Agreement,
     and all other shares of capital stock and other securities of
     International, now owned or hereafter acquired by Debtor.

               "ISSUING BANK" shall mean the person from time to time party
     to the Credit Agreement as "Issuing Bank."

               "LENDER DOCUMENTS" shall mean, as the same may be waived,
     amended, modified, extended, renewed, supplemented or replaced from
     time to time, the Credit Agreement, the Revolving Credit Notes, the
     Borrower Security Agreement, the Deed of Trust, the Guaranty, the
     Guarantor Security Agreement, the UIC Pledge Agreement, the UIC
     Subordination Agreement, the UIC-DEL Subordination Agreement, the L/C
     Agreements, this Agreement, and any and all other agreements,
     contracts, promissory notes and other instruments, security
     agreements, assignments, pledge agreements, indemnification
     agreements, mortgages, deeds of




















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     trust, leases, guaranties and other documents now or hereafter
     existing and evidencing, securing (directly or indirectly),
     guaranteeing (or in effect guaranteeing) or indemnifying (or in effect
     indemnifying) any of Lenders or Issuing Bank with respect to, any of
     the aforementioned documents or any obligations of any person to any
     of Lenders or Issuing Bank thereunder.

               "LENDER OBLIGATIONS" shall mean, as the same may be waived,
     amended, modified, extended, renewed, supplemented, refinanced,
     consolidated or replaced from time to time, all present and future
     Revolving Credit Loans, L/C Reimbursement Obligations and other
     obligations, indebtedness and liabilities of Debtor to each of Lenders
     and Issuing Bank arising under, evidenced by or in connection with the
     Credit Agreement or the other Lender Documents, including, without
     limitation, all principal amounts, including future advances,
     indemnification obligations, interest charges, fees, premiums,
     commissions and all other charges and sums, as well as all costs and
     expenses, including reasonable attorneys' fees and expenses, payable
     or reimbursable by Debtor under or in connection with the Credit
     Agreement or the other Lender Documents, whether direct or indirect,
     contingent or noncontingent, matured or unmatured, accrued or not
     accrued, liquidated or unliquidated, as well as all claims, demands,
     actions, causes of action and judgments arising from or relating to
     any of the foregoing, and including, without limitation, all claims
     against Debtor arising or re-arising on account of or as a result of
     any payment made by Debtor or any other person with respect to any
     obligations included in this definition which is rescinded or
     recovered from any of Lenders or Issuing Bank or restored or returned
     by any of Lenders or Issuing Bank under authority of any law, rule,
     regulation, order of court or Governmental Authority, or in connection
     with any compromise or settlement relating thereto or relating to any
     pending or threatened action, suit or proceeding relating thereto,
     whether arising out of any proceedings under the United States
     Bankruptcy Code or otherwise.  

               "LENDERS" shall mean the persons from time to time parties
     to the Credit Agreement as "Lenders."

               "MEDICAL" shall mean AAI Medical Corporation, a Maryland
     corporation.

               "MEDICAL SECURITIES" shall mean the shares of capital stock
     of Medical identified on the Securities Exhibit attached to this
     Agreement and incorporated by reference into this Agreement, and all
     other shares of capital stock and other securities of Medical, now
     owned or hereafter acquired by Debtor.

               "MICROFLITE" shall mean AAI Microflite Simulation
     International Corporation, a Maryland corporation.



















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







               "MICROFLITE SECURITIES" shall mean the shares of capital
     stock of Microflite identified on the Securities Exhibit attached to
     this Agreement and incorporated by reference into this Agreement, and
     all other shares of capital stock and other securities of Microflite,
     now owned or hereafter acquired by Debtor.

               "NOTE PURCHASE AGREEMENT" shall mean, as the same has been
     or may hereafter be waived, amended, modified, extended, renewed,
     supplemented or replaced from time to time, that certain Note Purchase
     Agreement dated July 15, 1992, among Debtor and Noteholders.

               "NOTEHOLDER DOCUMENTS" shall mean, as the same have been or
     may hereafter be waived, amended, modified, extended, renewed,
     supplemented or replaced from time to time, the Note Purchase
     Agreement, the Noteholder Notes, the UIC Noteholder Guaranty and any
     and all other agreements, contracts, promissory notes and other
     instruments, security agreements, assignments, pledge agreements,
     indemnification agreements, mortgages, deeds of trust, leases,
     guaranties and other documents now or hereafter existing and
     evidencing, securing, directly or indirectly, guaranteeing (or in
     effect guaranteeing) or indemnifying (or in effect indemnifying)
     Noteholders with respect to, any of the aforementioned documents or
     any obligations of any person to Noteholders thereunder.

               "NOTEHOLDER NOTES" shall mean, as the same have been or may
     hereafter be waived, amended, modified, extended, renewed,
     supplemented or replaced from time to time, that certain 8.65% Senior
     Note Due July 31, 1999, dated August 11, 1992, issued by Debtor to
     TRAL & CO, nominee of The Travelers Insurance Company, pursuant to the
     Note Purchase Agreement in the original principal amount of
     $9,000,000.00, that certain 8.65% Senior Note Due July 31, 1999, dated
     August 11, 1992, issued by Debtor to TRAL & CO, nominee of The
     Travelers Indemnity Company of Rhode Island, pursuant to the Note
     Purchase Agreement in the original principal amount of $3,000,000.00
     and assigned by The Travelers Indemnity Company of Rhode Island to The
     Travelers Insurance Company, that certain 8.65% Senior Note Due
     July 31, 1999, dated August 11, 1992, issued by Debtor to Principal
     Mutual Life Insurance Company pursuant to the Note Purchase Agreement
     in the original principal amount of $10,000,000.00, and that certain
     8.65% Senior Note Due July 31, 1999, dated August 11, 1992, issued by
     Debtor to Principal Mutual Life Insurance Company pursuant to the Note
     Purchase Agreement in the original principal amount of $3,000,000.00.

               "NOTEHOLDER OBLIGATIONS" shall mean, as the same have been
     or may hereafter be waived, amended, modified, extended, renewed,
     supplemented, refinanced, consolidated or replaced from time to time,
     all present and future obligations, indebtedness





















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     and liabilities of Debtor to each of Noteholders arising under,
     evidenced by  or in connection with the Noteholder Documents,
     including, without limitation, principal amounts (but not including
     any additional loans or advances by Noteholders to Debtor), interest
     charges, fees, premiums and all other charges and sums, as well as all
     costs and expenses, including reasonable attorneys' fees and expenses,
     payable or reimbursable by Debtor to each of Noteholders under or in
     connection with the Noteholder Documents, whether direct or indirect,
     contingent or noncontingent, matured or unmatured, accrued or not
     accrued, liquidated or unliquidated, as well as all claims, demands,
     actions, causes of action and judgments arising from or relating to
     any of the foregoing and including, without limitation, all claims
     against Debtor arising or re-arising on account of or as a result of
     any payment made by Debtor or any other person with respect to any
     obligations included in this definition which is rescinded or
     recovered from any of Noteholders or restored or returned by any of
     Noteholders under authority of any law, rule, regulation, order of
     court or Governmental Authority, or in connection with any compromise
     or settlement relating thereto or relating to any pending or
     threatened action, suit or proceeding relating thereto, whether
     arising out of any proceedings under the United States Bankruptcy Code
     or otherwise.  

               "NOTEHOLDERS" shall mean, collectively, Principal Mutual
     Life Insurance Company, an Iowa corporation, and The Travelers
     Insurance Company, a Connecticut corporation.

               "PERSON" shall mean any individual, corporation, limited
     liability company, partnership, joint venture, association, trust,
     business trust, Governmental Authority (or subdivision, agency or
     department thereof) or other entity of any kind.

               "SECURED OBLIGATIONS" shall mean, collectively, the Lender
     Obligations and the Noteholder Obligations.

               "SECURED PARTY NOTICE ADDRESS" shall mean 123 South Broad
     Street, Philadelphia, Pennsylvania 19109.

               "SECURITIES" shall mean the Carshell Securities, the
     Engineering Securities, the International Securities, the Medical
     Securities, the Microflite Securities, the Seti Securities, the
     Systems Securities and the Technologies Securities.

               "SECURITIES CERTIFICATES" shall mean the certificates
     evidencing the Securities identified on the Securities Exhibit
     attached to this Agreement and incorporated by reference into this
     Agreement.

               "SECURITIES COLLATERAL" shall mean:  (a) all present and
     future rights, titles and interests of Debtor in, to and


















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     under the Securities; (b) all present and future rights, titles,
     interests, powers, authorities, options, warrants, privileges and
     benefits of, accruing to or in any way relating to the Securities;
     (c) all present and future rights, titles and interests of Debtor in,
     to and under the Securities Documents and any oral agreements which,
     if written, would constitute Securities Documents, and all present and
     future rights, titles, interests, powers, authorities, options,
     warrants, privileges and benefits of Debtor arising under or in
     connection with the Securities Documents or any such oral agreements;
     (d) all present and future rights and claims of Debtor to the payment
     or receipt of money and other property of every kind for any reason
     arising under, on account of, in respect of, in evidence of, as an
     addition to, in substitution for, in replacement of, in exchange for,
     or in any other manner relating to, the Securities, the Securities
     Documents or any such oral agreements, whether in connection with any
     merger, consolidation, reorganization, recapitalization,
     reclassification, stock split, liquidation, increase or reduction of
     capital or other similar occurrence in respect of any of the
     Securities Issuers, or otherwise; (e) all present and future rights,
     titles and interests of Debtor in and to all present and future
     payments, receipts, collections, profits, revenues, dividends
     (including, without limitation, stock dividends, cash dividends and
     liquidating dividends), distributions, surplus, income, settlements,
     exchanges, benefits and other proceeds and avails in every form of or
     in any way relating to, the Securities, the Securities Documents or
     any such oral agreements, including, without limitation, all present
     and future rights and claims of Debtor to the payment or receipt of
     money and other property of every kind for any reason arising on
     account of or in any way relating to, and all present and future
     rights, titles and interests of Debtor in and to all proceeds in every
     form of, any voluntary or involuntary purchase, sale, transfer,
     conveyance, assignment, redemption, encumbrance, financing, re-
     financing, recapitalization, reorganization, exchange, liquidation,
     condemnation, taking, theft or disposition of any nature of, or any
     damage or casualty to, or any loss with respect to, the Securities,
     the Securities Documents, any such oral agreements or any of the
     Securities Issuers; and (f) all present and future proceeds of all of
     the foregoing, including, without limitation, cash proceeds, non-cash
     proceeds and proceeds acquired with cash proceeds, whether any such
     proceeds constitute consumer goods, farm products, equipment,
     inventory, documents of title, chattel paper, accounts, instruments or
     general intangibles, and including, without limitation, all proceeds
     of insurance policies insuring any of the foregoing or any risks
     relating to any of the foregoing.

               "SECURITIES DOCUMENTS" shall mean, as the same may be
     waived, amended, modified, extended, renewed, supplemented or replaced
     from time to time, the Securities Certificates and all other present
     and future certificates, agreements, contracts,



















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     instruments and other documents and writings evidencing or in any way
     relating to the Securities or any rights, titles, interests, powers,
     authorities, options, warrants, privileges or benefits of, accruing to
     or in any way relating to the Securities, including, without
     limitation, any such documents and writings in any way relating to the
     purchase, sale, transfer, conveyance, assignment, redemption,
     encumbrance, financing, re-financing, exchange, liquidation or
     disposition of any nature of, the Securities or any rights, titles,
     interests, powers, authorities, options, warrants, privileges or
     benefits of, accruing to or in any way relating to the Securities.

               "SECURITIES ISSUERS" shall mean Carshell, Engineering,
     International, Medical, Microflite, Seti, Systems and Technologies.

               "SETI" shall mean Seti, Inc., a Pennsylvania corporation.

               "SETI SECURITIES" shall mean the shares of capital stock of
     Seti identified on the Securities Exhibit attached to this Agreement
     and incorporated by reference into this Agreement, and all other
     shares of capital stock of Seti and other securities of Seti, now
     owned or hereafter acquired by Debtor.

               "SYSTEMS" shall mean AAI Systems Management, Inc., a
     Maryland corporation.

               "SYSTEMS SECURITIES" shall mean the shares of capital stock
     of Systems identified on the Securities Exhibit attached to this
     Agreement and incorporated by reference into this Agreement, and all
     other shares of capital stock and other securities of Systems, now
     owned or hereafter acquired by Debtor.

               "TECHNOLOGIES" shall mean AAI/ACL Technologies, Inc., a
     Maryland corporation.

               "TECHNOLOGIES SECURITIES" shall mean the shares of capital
     stock of Technologies identified on the Securities Exhibit attached to
     this Agreement and incorporated by reference into this Agreement and
     all other shares of capital stock and other securities of
     Technologies, now owned or hereafter acquired by Debtor.

               "UIC NOTEHOLDER GUARANTY" shall mean, as the same has been
     or may hereafter be waived, amended, modified, extended, renewed,
     supplemented or replaced from time to time, that certain Guaranty
     Agreement dated July 15, 1992, executed and delivered by UIC in favor
     of Noteholders.























     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







                  SECTION 2.  SECURITY INTEREST AND COLLATERAL


     2.1Grant of Security Interest.  As security for the Secured
        --------------------------
     Obligations, Debtor hereby grants to Secured Party, for the ratable
     benefit of Lenders, Issuing Bank and Noteholders according to the
     provisions of this Agreement and the Intercreditor Agreement, a lien
     and continuing security interest in, and pledges and assigns to
     Secured Party, for the ratable benefit of Lenders, Issuing Bank and
     Noteholders according to the provisions of this Agreement and the
     Intercreditor Agreement, the Collateral.  Even if any of the Secured
     Obligations shall at any time or from time to time be paid in full,
     Secured Party's security interest shall continuously exist until all
     of the Lender Obligations have been paid in full and there exists no
     commitment by any of Lenders or Issuing Bank which could give rise to
     any Lender Obligations.

               2.2 Additional Documents.  Debtor agrees to execute and
                   --------------------
     deliver to Secured Party, or cause to be executed and delivered to
     Secured Party, from time to time promptly after request by Secured
     Party and in form and content satisfactory to Secured Party, such
     security agreements, financing statements, amendments of financing
     statements, assignments of financing statements, security interest
     filing statements, mortgages, deeds of trust, assignments, notices,
     consents and other documents as Secured Party may request in good
     faith in order to confirm, supplement, preserve, protect or perfect,
     or to maintain the perfection of, Secured Party's security interest in
     the Collateral and Secured Party's rights under this Agreement.

               2.3  Representations and Warranties Concerning Collateral. 
                    ----------------------------------------------------
     Debtor represents and warrants that:  (a) no assignments of any of the
     Collateral have previously been made, and no financing statement,
     mortgage, deed of trust, assignment, notice of lien or other security
     document publicizing a security interest in or lien upon any of the
     Collateral is or will be on file in any recording or filing office,
     and the Collateral is and shall remain free and clear of all liens,
     security interests, assignments and encumbrances of every kind except
     as created hereby; and (b) Debtor is the legal and beneficial owner of
     all of the Collateral.

               2.4  Representations and Warranties Concerning Securities
                    ----------------------------------------------------
     Issuers and Securities Documents.  Debtor represents and warrants
     --------------------------------
     that:  (a) the execution, delivery and performance of this Agreement
     will not violate any term, provision or requirement of the articles of
     incorporation, corporate charter or bylaws of any of the Securities
     Issuers or any material instrument, contract, agreement, indenture,
     mortgage, deed of trust or other document or obligation to which any
     of the Securities Issuers is a party or by which any of the Securities















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     Issuers, or any of their property, is bound; (b) there are presently
     no Securities Documents except for the Securities Certificates;
     (c) the Securities evidenced by the Securities Certificates have been
     duly issued to Debtor and are fully paid and non-assessable; (d) none
     of the Securities constitute "margin stock," as defined in Regulation
     U of the Board of Governors of the Federal Reserve System; and
     (e) there are outstanding no options, warrants, convertible debt
     instruments or other similar instruments issued by any of the
     Securities Issuers conferring on any person any contingent or
     noncontingent rights to acquire any capital stock of any of the
     Securities Issuers.

               2.5  Additional Warranties and Agreements Concerning
                    -----------------------------------------------
     Collateral.  Debtor warrants and agrees that:  (a) Debtor will
     ----------
     promptly deliver to Secured Party, with such indorsements, powers
     and/or assignments as Secured Party may from time to time request in
     good faith, all Securities Documents now or hereafter in Debtor's
     possession or control; (b) except for cash dividends received by
     Debtor on account of the Securities at a time when no Event of Default
     shall be continuing (not including cash dividends in connection with
     the dissolution, liquidation or sale of any of the Securities Issuers 
     or any property of any of the Securities Issuers), Secured Party shall
     have the right to receive, and Debtor shall promptly deliver, or cause
     to be delivered promptly, to Secured Party and, until so delivered,
     Debtor shall hold as Secured Party's agent and bailee, all money and
     other property in any form and for any reason paid, payable,
     distributed or distributable to Debtor, or received or receivable by
     Debtor, on account of or in respect of, or constituting, Collateral,
     with such indorsements and/or assignments as Secured Party may from
     time to time request; (c) all Collateral delivered to Secured Party or
     coming into Secured Party's possession or control from time to time
     may be held by Secured Party as security for the Secured Obligations;
     (d) Secured Party shall have the right, in its discretion, at any time
     and from time to time (i) to sign Debtor's name on any drafts or
     orders against, or demands, notices or other documents directed to,
     persons obligated or liable to Debtor on account of or in respect of
     any of the Collateral, (ii) to indorse Debtor's name on any
     instruments, checks, drafts, orders or other items of payment
     constituting Collateral that may come into Secured Party's possession
     or control from time to time, and/or (iii) to cause, or to require
     Debtor to cause, any of the Collateral to be registered in the name of
     Secured Party or its nominees; (e) no check, draft, money order or
     other item of payment received by Secured Party or applied on account
     of any of the Secured Obligations shall constitute a final payment to
     Secured Party unless and until the item of payment shall be honored
     and finally paid to Secured Party in immediately available funds;
     (f) except as otherwise specifically permitted by this Agreement,
     Debtor will not, directly or indirectly, without Secured Party's prior
     written consent, sell, assign, transfer, convey or otherwise

















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     dispose of, or suffer or permit to occur any sale, assignment,
     transfer, conveyance or disposition of, any of the Collateral, or any
     interest therein; and (g) except as otherwise specifically permitted
     by this Agreement, Debtor will not, without Secured Party's prior
     written consent, exercise or waive, or permit the waiver or loss of,
     any rights of Debtor with respect to any of the Collateral.






























































     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







                               SECTION 3.  DEFAULT


     3.1Remedies.  Upon and at any time after the occurrence and during the
        --------
     continuance of any 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 other
     rights and remedies available to Secured Party, Lenders, Issuing Bank
     and Noteholders under the Lender Documents and the Noteholder
     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 law, all such rights and remedies being cumulative
     and enforceable alternatively, successively or concurrently: 
     (a) notify, and/or require Debtor to notify, any or all of the
     Securities Issuers and any or all other persons obligated or liable on
     or with respect to any of the Securities Collateral to deliver to
     Secured Party promptly all money and other property in any form and
     for any reason payable or distributable to Debtor, or receivable by
     Debtor, on account of or in respect of, or constituting, Securities
     Collateral; (b) in the place and stead of Debtor as though Secured
     Party were the absolute owner thereof, exercise any and all voting
     rights pertaining to the Securities Collateral and exercise any and
     all rights of conversion, exchange or subscription, and all other
     privileges, options and rights pertaining to the Securities
     Collateral, whether in connection with any merger, consolidation,
     insolvency, reorganization, recapitalization, dissolution, liquidation
     or other similar occurrence in respect of any of the Securities
     Issuers or otherwise, and, in connection therewith, to deposit and
     deliver any or all of the Securities Collateral to or with any
     committee, depository, transfer agent, registrar or other person upon
     such terms and conditions as Secured Party may determine in its
     discretion; (c) take exclusive possession of any or all of the
     Collateral from time to time and, so far as Debtor may give authority
     therefor, enter upon any premises on which any of the Collateral may
     be situated and remove the same therefrom, Debtor hereby waiving any
     and all rights to prior notice and to judicial hearing with respect to
     repossession of Collateral, and/or require Debtor, at Debtor's
     expense, to assemble and deliver any or all of the Collateral to such
     place or places as Secured Party may reasonably request; and
     (d) enforce the liens and security interests granted to Secured Party
     hereunder by collecting or liquidating all or any part of the
     Collateral or selling, assigning, re-assigning or otherwise disposing
     of all or any part of the Collateral or any interest therein, in one
     or more parcels, at the same or different times, at public or private
     sale or disposition, or otherwise.

               3.2  Collateral Dispositions.  Debtor agrees that commercial
                    -----------------------
     reasonableness and good faith require Secured Party to give Debtor no
     more than ten (10) days prior written notice of

















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     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.  All sales or other dispositions of
     Collateral may be made for cash, upon credit or for future delivery. 
     Debtor acknowledges and agrees that Secured Party may, in its
     discretion, elect to dispose of the Securities after the occurrence
     and during the continuance of an Event of Default by causing any of
     the Securities Issuers to dissolve, liquidate and make liquidating
     dividends or distributions, and that such means of disposing of the
     Securities is commercially reasonable.  In no event shall Debtor be
     credited with any part of the proceeds of liquidation, sale or other
     disposition of any Collateral until final payment thereon has been
     received by Secured Party in immediately available funds, and Secured
     Party shall have no obligation to delay any liquidation, sale or other
     disposition because the same may result in the imposition of any
     forfeiture, premium or penalty.  In connection with any enforcement by
     Secured Party of the liens and security interests granted to Secured
     Party pursuant to this Agreement, Secured Party may demand,
     compromise, collect, enforce and sue for all money and other property
     in any form and for any reason payable or distributable to Debtor, or
     receivable by Debtor, on account of or in respect of, or constituting,
     Collateral, and otherwise exercise all rights of Debtor with respect
     to the Collateral, and all Collateral or proceeds of Collateral
     delivered to Secured Party or coming into Secured Party's possession
     or control from time to time may be applied by Secured Party from time
     to time, in whole or in part and in such order as Secured Party may
     determine in its discretion, to any of the Secured Obligations. 
     Debtor covenants and agrees, at Debtor's expense, to execute and
     deliver or cause to be executed and delivered, and to do or cause to
     be done, all such acts, things, instruments and documents as may, in
     the opinion of Secured Party or counsel to Secured Party, be necessary
     or advisable to make all sales and dispositions of Collateral valid,
     binding and enforceable and in compliance with all applicable laws,
     rules and regulations and all judgments, orders, awards, decrees,
     writs and injunctions of all courts, arbitrators or governmental
     authorities having jurisdiction over any such sales or dispositions. 
     Debtor acknowledges and agrees that a breach of any of the covenants
     contained in this Subsection or in Subsection 3.3 will cause
     irreparable injury to Secured Party and that Secured Party has no
     adequate remedy at law in respect of any such breach.  Debtor
     therefore acknowledges and agrees that each and every covenant
     contained in this Subsection and in Subsection 3.3 shall be
     specifically enforceable against Debtor, and Debtor hereby waives to
     the extent permitted by applicable law, and agrees not to assert, any
     defenses against an action for specific performance of such covenants,
     except for a defense that the Secured Obligations are not due and
     payable.

               3.3  Certain Sales of Collateral.  If Secured Party
                    ---------------------------


















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     shall determine to exercise its right to sell or otherwise dispose of
     any or all of the Securities Collateral and if, in the opinion of
     Secured Party or counsel for Secured Party, it is necessary or
     advisable to have such Securities Collateral, or any portion thereof,
     registered under the provisions of the Securities Act of 1933 (as
     amended from time to time and, together with any successor
     legislation, the "Securities Act"), Debtor covenants and agrees that
     Debtor will cause each of the Securities Issuers, as applicable, and
     its directors and officers, to execute and deliver, at Debtor's
     expense, all such instruments and documents, and to do or cause to be
     done all other acts and things as may be necessary or advisable, in
     the opinion of Secured Party or counsel for Secured Party, to register
     such Securities Collateral, or such portion thereof, under the
     provisions of the Securities Act and to cause the registration
     statement relating thereto to become effective and to remain effective
     for a period of one (1) year from the date of the first public
     offering of such Securities Collateral, or such portion thereof, and
     to make all amendments thereto and/or to the related prospectus which,
     in the opinion of Secured Party or counsel for Secured Party, are
     necessary or advisable, all in conformity with the requirements of the
     Securities Act and the rules and regulations of the Securities and
     Exchange Commission applicable thereto.  Debtor also covenants and
     agrees that Debtor will cause each of the Securities Issuers, as
     applicable, and its directors and officers, to comply with the
     provisions of the securities or "Blue Sky" laws of any jurisdiction
     which Secured Party shall designate.  Debtor recognizes that,
     notwithstanding the foregoing provisions of this Subsection, Secured
     Party may be unable to effect a public sale of all or a part of the
     Securities Collateral by reason of certain prohibitions contained in
     the Securities Act and other federal and/or State securities laws, but
     may be compelled to resort to private sale to a purchaser or
     purchasers from a restricted group of bidders who will be obliged to
     agree, among other things, to acquire such Securities Collateral for
     its or their own account, for investment and without a view to the
     distribution or resale thereof.  Debtor acknowledges and agrees that a
     private sale so made may be at a price and on other terms less
     favorable than if such Securities Collateral were sold at public sale,
     and agrees that Secured Party has no obligation to cause, or to delay
     the sale of any of such Securities Collateral for the period of time
     necessary to permit, any person to register such Securities Collateral
     for sale under such laws.  Debtor agrees that private sales made under
     the foregoing circumstances shall be deemed to have been made in a
     commercially reasonable manner.

               3.4 Expenses.  Debtor agrees to pay to Secured Party, each
                   --------
     Lender, each Noteholder and Issuing Bank upon its demand from time to
     time, the amount of all expenses, including reasonable attorneys' fees
     and expenses, paid or incurred by it (a) in exercising or enforcing or
     consulting with counsel


















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     concerning, any of its rights hereunder or under law, or (b) in
     defending any and all non-meritorious or previously waived demands,
     claims, counterclaims, cross-claims, causes of action, litigation and
     proceedings of every kind and nature asserted, commenced or instituted
     against it or any of its officers, directors, employees or agents, by
     Debtor, any Subsidiary of Debtor or any Other Obligor on account of,
     as a result of or relating to, any action taken or not taken by
     Secured Party, any Lender, any Noteholder or Issuing Bank in
     connection with the Collateral or enforcement or exercise by it of any
     of its rights or remedies under this Agreement or under law.  Debtor
     also agrees to pay to Secured Party, each Lender, each Noteholder and
     Issuing Bank upon its demand from time to time, interest on the
     outstanding amount of such expenses, from the date of demand for
     payment of such expenses until the same are paid in full, at the rate
     from time to time applicable to Base Rate Loans.


                        SECTION 4.  ADDITIONAL PROVISIONS


     4.1Further Assurances, Power of Attorney.  Debtor agrees promptly to
        -------------------------------------
     do, make, execute and deliver all such additional and further acts,
     things, deeds, assurances, instruments and documents as Secured Party
     may request in good faith to vest in and assure to Secured Party its
     rights hereunder or in any of the Collateral.  Debtor hereby appoints
     Secured Party and its designees as attorney-in-fact of Debtor,
     irrevocably and with power of substitution, with authority to execute
     and deliver from time to time, in the name and stead of Debtor, all
     documents which Debtor is required to, but has failed or refused to,
     execute and deliver to Secured Party pursuant to this Agreement, and
     with authority to take all of the actions from time to time on behalf
     of Debtor, and in the name and stead of Debtor, which Secured Party is
     authorized to take under this Agreement or which Secured Party in its
     discretion exercised in good faith deems necessary or advisable in
     order to cause Debtor to be in compliance with any of the terms of
     this Agreement or in order to carry out and enforce this Agreement. 
     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 which does not arise from its gross negligence or willful
     misconduct.  This power of attorney is coupled with an interest and is
     irrevocable so long as any of the Secured Obligations remain unpaid or
     unperformed or there exists any commitment by Lenders or Noteholders
     which could give rise to any Secured Obligations.

               4.2 Waiver of Trial by Jury.  Each of Debtor and Secured
                   -----------------------
     Party agrees that any action, suit or proceeding involving any claim,
     counterclaim or cross-claim arising out of or in any way relating,
     directly or indirectly, to this Agreement, or any liabilities, rights
     or interests of Debtor,

















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     Secured Party or any other person arising out of or in any way
     relating, directly or indirectly, to this Agreement, shall be tried by
     a court and not by a jury.  Debtor and Secured Party hereby waives any
     right to trial by jury in any such action, suit or proceeding, with
     the understanding and agreement that this waiver constitutes a waiver
     of trial by jury of all claims, counterclaims and cross-claims against
     all parties to such actions, suits or proceedings, including claims,
     counterclaims and cross-claims against parties who are not parties to
     this Agreement.  This waiver is knowingly, willingly and voluntarily
     made by Debtor and Secured Party, and Debtor and Secured Party
     acknowledges and agrees that this waiver of trial by jury is a
     material aspect of the agreements between Debtor and Secured Party and
     that no representations of fact or opinion have been made by any
     person to induce this waiver of trial by jury or to modify, limit or
     nullify its effect.

               4.3  Additional Waivers.  Except in the case of any notices
                    ------------------
     specifically required to be given to Debtor by Secured Party, any
     Lender, Issuing Bank or any Noteholder pursuant to this Agreement, any
     of the Lender Documents or any of the Noteholder Documents, Debtor
     hereby waives notice of each and every one of the following acts,
     events and/or conditions and agrees that, without necessity for any
     express reservation of rights against Debtor, neither the occurrence
     or existence of any such act, event or condition, nor Secured Party's,
     any Lender's, Issuing Bank's or any Noteholder's commission of or
     omission to do any such act, event or condition, in any number of
     instances, shall in any way release, discharge, impair or diminish any
     of the Secured Obligations, except as otherwise specifically agreed by
     Secured Party in writing:  (a) the amendment, modification, renewal,
     extension or refinancing of, or the granting by Secured Party, any
     Lender, Issuing Bank or any Noteholder of any indulgence of any nature
     with respect to, or the invalidity, voidability, unenforceability,
     compromise, settlement, release, waiver, discharge or impairment, in
     whole or in part, of, any of the Secured Obligations or any obligation
     of any Other Obligor with respect to any of the Secured Obligations;
     (b) any defense of Debtor or any Other Obligor to payment of any of
     the Secured Obligations; (c) the addition of any maker, guarantor,
     surety, endorser, indemnitor or other person primarily or secondarily
     liable for or obligated upon any of the Secured Obligations;
     (d) assumption of any of the Secured Obligations by any other person,
     whether by assignment, sale, merger, consolidation, sublease,
     conveyance or otherwise; (e) delivery to Secured Party, any Lender,
     Issuing Bank or any Noteholder or acceptance by Secured Party, any
     Lender, Issuing Bank or any Noteholder of any promissory note or other
     instrument or writing evidencing or otherwise relating to any of the
     Secured Obligations; (f) the institution of any suit, the obtaining of
     any judgment or the exercise of any other right or remedy against
     Debtor or any Other Obligor; (g) the sale, exchange, pledge, release,
     disposition,


















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     surrender, loss, destruction, damage to or impairment of, any
     Collateral; (h) the creation, perfection, continuation, amendment,
     modification, invalidity, voidability, unenforceability, compromise,
     settlement, subordination, release, waiver, discharge, impairment or
     loss of priority, in whole or in part, of, any security interest, lien
     other encumbrance directly or indirectly securing any of the
     Obligations; or (i) any other event, circumstance or condition which
     might otherwise constitute a legal or equitable discharge of a
     borrower.  Debtor also hereby waives, to the extent the same may be
     waived under applicable law:  (a) notice of acceptance by Secured
     Party 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 under this Agreement or under law, provided that the same did
     not arise from Secured Party's negligence or willful misconduct;
     (c) all claims and causes of action of Debtor against Secured Party
     for punitive, exemplary, indirect, special, consequential or other
     non-compensatory damages; (d) all rights of redemption of Debtor with
     respect to any of the Collateral; (e) in the event Secured Party seeks
     to repossess any or all of the Collateral by judicial proceedings, any
     bonds or demands for possession which otherwise may be required;
     (f) all rights of Debtor to have marshalled the Collateral or any
     other security for any of the Secured Obligations; (g) diligence in
     the enforcement or collection of all of the Obligations;
     (h) presentment, protest, notice of protest and notice of non-payment
     with respect to all of the Secured Obligations; and (i) any duty or
     obligation of Secured Party to disclose to Debtor any information
     concerning any other customer or client, or prospective customer or
     client, of Secured Party.  Debtor agrees that Secured Party may
     exercise any or all of its rights and/or remedies without resorting
     to, without regard to, and regardless of the adequacy of, any security
     or other sources of liability with respect to any of the Secured
     Obligations.  Neither any failure nor any delay on the part of Secured
     Party in exercising any right, power or remedy 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.

               4.4 Modifications, Notices.  No modification or waiver of
                   ----------------------
     any provision of this Agreement, and no consent by Secured Party to
     any failure of any of Debtor to comply with any provision of this
     Agreement, shall in any event be effective unless the same shall be in
     writing and signed by the person against whom enforcement thereof is
     sought, 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 circumstance shall entitle Debtor to any
     other or further notice or demand in the same, similar or other
     circumstances.  All notices, requests and demands to or upon the



















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     respective parties hereto to be effective shall be in writing and
     shall be deemed to have been duly given or made when delivered by
     hand, or, if earlier, three (3) calendar days after being deposited in
     the mail, postage prepaid, or when transmitted by telecopy
     transmission, provided that any such notice or communication to Debtor
     shall be hand-delivered or transmitted to Debtor at the Debtor Notice
     Address (or at such other address as Debtor may specify to Secured
     Party in writing from time to time), and any such notice or
     communication to Secured Party shall be hand-delivered or transmitted
     to Secured Party at the Secured Party Notice Address (or at such other
     address as Secured Party may specify to Debtor in writing from time to
     time).

               4.5 Survival, Merger and Counterparts.  All representations,
                   ---------------------------------
     warranties, covenants, conditions and agreements contained herein
     shall survive the execution and delivery hereof.  Debtor shall
     continue to observe, comply with and perform all warranties,
     covenants, conditions and agreements to be observed, complied with or
     performed by Debtor under this Agreement until all of the Lender
     Obligations have been paid in full and there exists no commitment by
     any of Lenders or Issuing Bank which could give rise to any Lender
     Obligations.  This Agreement contains the entire agreement of the
     parties with respect to the matters covered and the transactions
     contemplated hereby and thereby, and no 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 or
     therein, shall be valid or binding.  This Agreement may be executed in
     any number of counterparts and by different parties 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 agreement.

               4.6 Law, Jurisdiction, Process, Transfers and
                   -----------------------------------------
     Unenforceability.  The performance and construction of this Agreement
     ----------------
     shall be governed by the internal laws of the State of Maryland
     (exclusive of principles of conflicts of laws).  Debtor agrees that
     any suit, action or proceeding with respect to the Collateral or this
     Agreement may be brought in any state or federal court located in the
     State of Maryland.  Debtor consents to the in personam jurisdiction of
                                                -- --------
     such courts and Debtor irrevocably waives any objection to, and any
     right of immunity from, the jurisdiction of such courts or the
     execution of judgments resulting therefrom, on the grounds of venue or
     the convenience of the forum.  In addition, any such suit, action or
     proceeding instituted by Secured Party may be brought in such other
     courts in which jurisdiction and venue may be appropriate.  Debtor
     agrees that service of process in any such suit, action or proceeding
     may be effected by mailing a copy thereof by registered or certified
     mail (or any substantially similar form of mail), postage prepaid, to
     Debtor at the Debtor Notice Address (or at such other address as
     Debtor may specify to Secured Party














     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     in writing from time to time).  This Agreement shall be binding upon
     and inure to the benefit of the parties hereto and their respective
     successors and assigns, and each reference in this Agreement to any of
     the parties hereto shall be deemed to include the successors and
     assigns of such party, including, in the case of Debtor, the debtor,
     the debtor in possession and trustee in any case under any chapter of
     the United States Bankruptcy Code in which Debtor is debtor.  Debtor
     may not assign this Agreement or any of its rights hereunder without
     Secured Party's prior written consent.  Subject to applicable law and
     agreements, any of Lenders, Issuing Bank or Noteholders may at any
     time, in its discretion, assign, transfer or pledge to any person, or
     grant to any person a security interest in, this Agreement or any of
     its rights hereunder.  Subject to applicable law and agreements, any
     of Lenders, Issuing Bank or Noteholders may sell, in such amounts,
     upon such terms and to such persons as it may determine,
     participations in its beneficial interests under this Agreement.  If
     any term, provision or condition, or any part thereof, of this
     Agreement shall for any reason be found or held invalid or
     unenforceable by any court or governmental agency, such invalidity or
     unenforceability shall not affect the remainder of such term,
     provision or condition, nor any other term, provision or condition,
     and this Agreement shall survive and be construed as if such invalid
     or unenforceable term, provision or condition had not been contained
     herein or therein; provided, however, that if any rate of interest
     provided under this Agreement does or shall exceed the maximum
     interest rate which Debtor is permitted by law to contract or agree to
     pay, then such rate of interest shall immediately be deemed to be
     reduced to such maximum rate and all previous payments of interest in
     excess of the maximum rate shall be deemed to have been payments in
     reduction of principal and not of interest.

               IN WITNESS WHEREOF, Debtor and Secured Party have duly
     executed this Agreement under seal as of the day and year first
     written above.


     ATTEST/WITNESS:                    FIRST FIDELITY BANK, NATIONAL
                                           ASSOCIATION



     _________________________
     By:__________________________(SEAL)
                                           Michael W. Coiley
                                           Vice President


                                        AAI CORPORATION




















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







                                        By:__________________________(SEAL)
     -------------------------
                                           Paul J. Michaud
                                           Vice President
































































     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







                               SECURITIES EXHIBIT
                               -------------------



     Carshell Securities:

     1,000 shares of the common stock of Carshell, evidenced by Certificate
     No. 1 issued on September 10, 1993


     Engineering Securities:

     100 shares of the common stock of Engineering, evidenced by
     Certificate No. 2 issued on August 26, 1994


     International Securities:

          30 shares of the common stock of International, evidenced by
          Certificate No. 1 issued on December 30, 1971


     Medical Securities:

          5,000 shares of the common stock of Medical, evidenced by
          Certificate No. 1 issued on March 9, 1990


     Microflite Securities:

          1,000 shares of the common stock of Microflite, evidenced by
          Certificate No. 1 issued on June 19, 1991


     Seti Securities:

          25,000 shares of the common stock of Seti, evidenced by
          Certificate No. 4 issued on August 26, 1994





























     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     Systems Securities:

          100 shares of the common stock of Systems, evidenced by
          Certificate No. 1 issued on April 25, 1989


     Technologies Securities:

          1,000 shares of the common stock of Technologies, evidenced by
          Certificate No. 2 issued on August 26, 1994


























































     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC







     STATE OF MARYLAND, CITY OF BALTIMORE, SS:


               I HEREBY CERTIFY that on this ____________ day of
     _____________________, 1994, before me, the undersigned, a Notary
     Public of said State, personally appeared Paul J. Michaud, who
     acknowledged himself to be the Vice President of AAI Corporation, and
     that he, as such, being authorized so to do, executed the foregoing
     instrument for the purposes therein contained.

               WITNESS my hand and Notarial Seal.



                                             ______________________________
                                             Notary Public

     My Commission expires:

           10/1/97
     --------------------


     STATE OF MARYLAND, CITY OF BALTIMORE, SS:


               I HEREBY CERTIFY that on this ___________ day of
     ______________________, 1994, before me, the undersigned, a Notary
     Public of said State, personally appeared Michael W. Coiley, who
     acknowledged himself to be the Vice President of First Fidelity Bank,
     National Association, and that he, as such, being authorized so to do,
     executed the foregoing instrument for the purposes therein contained.

               WITNESS my hand and Notarial Seal.


                                             ______________________________
                                             Notary Public

     My Commission expires:

           10/1/97
     --------------------






















     -  -
     100694
     \\\BA\63944\0001\AG000904.DOC