<PAGE>


                         L-3 COMMUNICATIONS CORPORATION

                           CONSENT AND THIRD AMENDMENT
                TO AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT

         This CONSENT AND THIRD AMENDMENT TO THE AMENDED AND RESTATED 364-DAY
CREDIT AGREEMENT (this "AMENDMENT") is dated as of November 16, 2000 and entered
into by and among L-3 COMMUNICATIONS CORPORATION, a Delaware corporation (the
"BORROWER") which is wholly owned by L-3 COMMUNICATIONS HOLDINGS, INC., a
Delaware corporation ("HOLDINGS"), the Lenders party to the Credit Agreement
referred to below on the date hereof (the "LENDERS"), BANK OF AMERICA, N.A.,
("BOA"), as administrative agent for the Agents (as defined below) and the
Lenders (in such capacity, the "ADMINISTRATIVE AGENT") and certain financial
institutions named as co-agents, LEHMAN COMMERCIAL PAPER, INC. ("LCPI") as
syndication agent and documentation agent (in such capacity, the "SYNDICATION
AGENT" and the "DOCUMENTATION AGENT"). All capitalized terms used herein without
definition shall have the same meanings herein as set forth in the Credit
Agreement (as defined below).

                              W I T N E S S E T H:

         WHEREAS, the Borrower, the Lenders, the Syndication Agent, the
Documentation Agent, the Administrative Agent and certain other parties have
entered into the Amended and Restated 364-Day Credit Agreement dated as of April
24, 2000 (as amended, supplemented, restated or otherwise modified from time to
time, the "CREDIT AGREEMENT"); and

         WHEREAS, the Borrower desires that the Lenders consent to the waiver of
certain prepayment requirements and certain other amendments to the Credit
Agreement.

         NOW, THEREFORE, in consideration of the premises and the agreements,
provisions and covenants herein contained, the parties hereto agree as follows:

         SECTION 1. CONSENT TO LIMITED WAIVER. Borrower has requested that the
Required Class Lenders consent to a waiver of the mandatory prepayment of the
Loans and permanent reduction in Commitments required by Section 2.6(b)(i) of
the Credit Agreement with respect to the Net Proceeds of Indebtedness incurred
in connection with the issuance of up to the Designated Issue Amount (as defined
herein) of Permitted Convertible Securities (the "Requested Waiver"). Subject to
the satisfaction of the conditions precedent to this Amendment set forth in
Section 3 hereof, each Lender executing this Amendment hereby consents to the
Requested Waiver. As used herein, "Designated Issue Amount" shall mean the
aggregate principal amount of Permitted Convertible Securities actually issued
on or prior to January 31, 2001, which shall not in any event exceed
$300,000,000.
<PAGE>

         SECTION 2. AMENDMENTS. Subject to the satisfaction of each of the
conditions to effectiveness set forth in Section 3 of this Amendment, the
Borrower and the Lenders hereby agree to amend the Credit Agreement as follows:

         2.1 The definition of "New Investment Sublimit" appearing in subsection
1.1 of the Credit Agreement is hereby amended by deleting the term
"$650,000,000" and inserting the term "$850,000,000" in place thereof.

         2.2 Subsection 1.1 of the Credit Agreement is hereby further amended to
add the following new defined term in alphabetical order:

         "Third Amendment Effective Date": shall have the meaning given to such
term in that certain Consent and Third Amendment to the Amended and Restated
364-Day Credit Agreement dated as of November 16, 2000.

         2.3 Subsection 2.18 of the Credit Agreement is hereby amended by adding
at the end thereof the following additional language:

                  "Subject to the occurrence of the Third Amendment Effective
         Date, Borrower hereby agrees to pay to each Lender submitting to the
         Administrative Agent an executed counterpart to the Third Amendment to
         this Agreement on or before 12:00 (noon) (New York time) on November
         29, 2000 (a "Third Amendment Lender") a non-refundable amendment fee
         (the "Third Amendment Fee") in an amount equal to 5 basis points
         multiplied by the Commitment of such Lender under the Credit Agreement.
         The Third Amendment Fee owing to each Third Amendment Lender shall be
         paid in immediately available funds by the Borrower to the
         Administrative Agent for the benefit of such Third Amendment Lenders
         not later than noon (New York time) on the first Business Day following
         the occurrence of the Third Amendment Effective Date."

         2.4 Subsection 7.4(h) of the Credit Agreement is hereby amended and
restated in its entirety to read as follows:

                  (h) Guarantee Obligations in respect of up to $400,000,000
         principal amount of Convertible Securities issued by Holdings having an
         initial annual interest rate not in excess of 7% per annum which
         initial annual interest rate may be subject to subsequent adjustments
         in accordance with the terms of such Convertible Securities in the
         event of a Reset Transaction (the "Permitted Convertible Securities").
         As used herein, a "Reset Transaction" shall have the meaning ascribed
         to such term in the Indenture governing the issuance of the Convertible
         Senior Subordinated Notes of Holdings due 2009 as in effect at the time
         of such issuance.

         2.5 Subsection 7.9(e) of the Credit Agreement is hereby amended by
deleting the term "6 months" each place it appears therein, and inserting the
term "12 months" in place thereof.

                                       2
<PAGE>

         SECTION 3. CONDITIONS TO EFFECTIVENESS. Sections 1 and 2 of this
Amendment shall be deemed effective as of the date when each of the following
conditions precedent have been satisfied (such effective date occurring upon
satisfaction of such conditions precedent being referred to herein as the "THIRD
AMENDMENT EFFECTIVE DATE"):

         3.1. The Required Class Lenders shall have delivered to the
Administrative Agent an executed original or facsimile of a counterpart of this
Amendment, the Second Amendment to the Second Amended and Restated Credit
Agreement of even date herewith and the Second Amendment to the New 364 Day
Credit Agreement of even date herewith.

         3.2. The Borrower shall have delivered to the Administrative Agent
executed copies of this Amendment and each of the other Credit Parties shall
have delivered to the Administrative Agent executed copies of the Guarantors'
Consent and Acknowledgment to this Amendment in the form attached hereto.

         3.3. All fees owing to the Administrative Agent by the Borrower and all
attorneys fees and disbursements incurred by the Agents in connection with the
administration of the Credit Agreement and/or this Amendment shall have been
paid.

         3.4. The Administrative Agent shall have received a secretary's or
assistant secretary's certificate of Borrower certifying board resolutions
authorizing the execution, delivery and performance of this Amendment by
Borrower.

         3.5. The representations and warranties contained in Section 4 hereof
shall be true and correct in all respects.

         3.6. All conditions set forth in Sections 3.1 through 3.5 of the Second
Amendment to the Second Amended and Restated Credit Agreement of even date
herewith and the Second Amendment to the New 364 Day Credit Agreement of even
date herewith shall have been satisfied.

         SECTION 4. REPRESENTATIONS AND WARRANTIES. In order to induce Lenders
to enter into this Amendment and to amend the Credit Agreement in the manner
provided herein, the Borrower represents and warrants to each Lender that the
following statements are true, correct and complete:

         4.1. Authorization and Enforceability. (a) The Borrower has all
requisite corporate power and authority to enter into this Amendment and to
carry out the transactions contemplated by, and perform its obligations under,
the Credit Agreement as amended by this Amendment (the "AMENDED AGREEMENT"), (b)
the execution and delivery of this Amendment has been duly authorized by all
necessary corporate action on the part of the Borrower and (c) this Amendment
and the Amended Agreement have been duly executed and delivered by the Borrower
and, when executed and delivered, will be the legally valid and binding
obligations of the Borrower, enforceable against the Borrower in accordance with
their respective terms, except


                                       3
<PAGE>

as may be limited by bankruptcy, insolvency, reorganization, moratorium or
similar laws relating to or limiting creditors' rights generally or by equitable
principles relating to enforceability.

         4.2. Incorporation of Representations and Warranties From Credit
Agreement. The representations and warranties contained in Section 4 of the
Credit Agreement are and will be true, correct and complete in all material
respects on and as of the Third Amendment Effective Date to the same extent as
though made on and as of that date, except to the extent such representations
and warranties specifically relate to an earlier date, in which case they were
true, correct and complete in all material respects on and as of such earlier
date.

         4.3. Absence of Default and Setoff. No event has occurred and is
continuing or will result from the consummation of the transactions contemplated
by this Amendment that would constitute an Event of Default or a potential Event
of Default and no defense, setoff or counterclaim of any kind, nature or
description exists to the payment and performance of the obligations owing by
Borrower to the Agents and the Lenders.

         SECTION 5. MISCELLANEOUS.

         5.1. Effect on the Credit Agreement and the other Credit Documents.
Except as specifically amended by this Amendment, the Credit Agreement and the
other Credit Documents shall remain in full force and effect and are hereby
ratified and confirmed. The execution, delivery and performance of this
Amendment shall not, except as expressly provided herein, constitute a waiver of
any provision of, or operate as a waiver of any right, power or remedy of the
Administrative Agent or any Lender under, the Credit Agreement or any of the
other Credit Documents.

         5.2. Fees and Expenses. The Borrower acknowledges that all costs, fees
and expenses as described in Section 10.5 of the Credit Agreement incurred by
Administrative Agent and its counsel with respect to this Amendment and the
documents and transactions contemplated hereby shall be for the account of the
Borrower.

         5.3. GOVERNING LAW. THIS AGREEMENT AND THE RIGHTS AND OBLIGATIONS OF
THE PARTIES HEREUNDER SHALL BE GOVERNED BY, AND CONSTRUED AND INTERPRETED IN
ACCORDANCE WITH, THE LAW OF THE STATE OF NEW YORK.

         5.4. SUBMISSION TO JURISDICTION; WAIVERS; WAIVER OF JURY TRIAL;
ACKNOWLEDGMENTS; CONFIDENTIALITY. Each of the terms and conditions set forth in
Sections 10.12, 10.13, 10.14 and 10.15 of the Credit Agreement are hereby
incorporated into this Amendment as if set forth fully herein except that each
reference to "Agreement" therein shall be deemed to be a reference to
"Amendment" herein.

         5.5. Counterparts; Effectiveness. This Amendment may be executed in any
number of counterparts and by different parties hereto in separate counterparts,
each of which when so executed and delivered shall be deemed an original, but
all such counterparts together


                                       4
<PAGE>

shall constitute but one and the same instrument. Except for the terms of
Sections 1 and 2 hereof (which shall only become effective on the Third
Amendment Effective Date), this Amendment shall become effective upon the
execution of a counterpart hereof by the Borrower and the Required Lenders and
receipt by the Borrower and the Administrative Agent of written or telephonic
notification of such execution and authorization of delivery thereof.

                            [SIGNATURE PAGES FOLLOW]


                                       5
<PAGE>


                  IN WITNESS WHEREOF, the parties hereto have caused this
Amendment to be duly executed and delivered by their proper and duly authorized
officers as of the day and year first above written.

                             L-3 COMMUNICATIONS CORPORATION


                             By:      /s/ Lawrence O'Brien
                                 ----------------------------------------------
                                 Title: Vice-President and Treasurer

                             BANK OF AMERICA, N.A.,
                              as Administrative Agent


                             By:      /s/ Liliana Claar
                                 ----------------------------------------------
                                 Title: Vice-President


                             BANK OF AMERICA, N.A.,
                              as a Lender


                             By:      /s/ Lisa Choi
                                 ----------------------------------------------
                                 Title: Vice-President

                             LEHMAN COMMERCIAL PAPER INC.,
                                  as Documentation Agent, Syndication Agent
                                  and as a Lender


                             By:      /s/ G. Andrew Keith
                                 ----------------------------------------------
                                 Title:


               [SIGNATURE PAGES TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]

<PAGE>

                             THE BANK OF NEW YORK


                             By:      /s/ Ken Sneider
                                 ----------------------------------------------
                                 Title: Vice-President




               [SIGNATURE PAGES TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]



<PAGE>


                             THE BANK OF NOVA SCOTIA


                             By:       /s/ Todd S. Meller
                                 ----------------------------------------------
                                 Title: Managing Director




               [SIGNATURE PAGES TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]



<PAGE>



                             BANK ONE, NA

                             By:      /s/ Andrea S. Kantor
                                 ----------------------------------------------
                                 Title: First Vice President






               [SIGNATURE PAGES TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]



<PAGE>



                             FLEET NATIONAL BANK


                             By:      /s/ Jana Dombrowski
                                 ----------------------------------------------
                                 Title: Vice President





               [SIGNATURE PAGES TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]



<PAGE>



                             THE BANK OF TOKYO - MITSUBISHI TRUST COMPANY


                             By:      /s/ Chris Droussiotis
                                 ----------------------------------------------
                                 Title: Vice Prsident






               [SIGNATURE PAGES TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]


<PAGE>



                             CREDIT LYONNAIS NEW YORK BRANCH


                             By:      /s/ Scott R. Chappelka
                                 ----------------------------------------------
                                 Title: Vice President







               [SIGNATURE PAGES TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]


<PAGE>



                             FIRST UNION COMMERCIAL CORPORATION


                             By:      /s/ Barbara Van Meerten
                                 ----------------------------------------------
                                 Title: Vice President






               [SIGNATURE PAGES TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]



<PAGE>



                             FLEET NATIONAL BANK


                             By:      Jana Dombrowski
                                 ----------------------------------------------
                                 Title: Vice President







               [SIGNATURE PAGES TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]



<PAGE>



                             THE FUJI BANK, LIMITED


                             By:      /s/ Nobuoki Koike
                                 ----------------------------------------------
                                 Title: Vice President & Senior Team Leader







               [SIGNATURE PAGES TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]


<PAGE>



                             HSBC BANK USA


                             By:      /s/ D. C. English
                                 ----------------------------------------------
                                 Title: Associate Director







               [SIGNATURE PAGES TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]


<PAGE>



    [GUARANTORS' ACKNOWLEDGMENT AND CONSENT TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]

                             SOCIETE GENERALE


                             By:      /s/ Jose A. Moreno
                                 ----------------------------------------------
                                 Title: Director




    [GUARANTORS' ACKNOWLEDGMENT AND CONSENT TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]

<PAGE>



                     Guarantors' Acknowledgment and Consent

                  Each of the undersigned hereby acknowledges receipt of the
attached Amendment and consents to the execution and performance thereof by L-3
Communications Corporation. Each of the undersigned hereby also reaffirms that
the guarantee of such undersigned in favor of the Administrative Agent for the
ratable benefit of the Lenders and the Agents remains in full force and effect
and acknowledges and agrees that there is no defense, setoff or counterclaim of
any kind, nature or description to obligations arising under such guarantee.

Date: _Nov 16, 2000

                             L-3 COMMUNICATIONS HOLDINGS, INC.


                             By: /s/ Christopher C. Cambria
                                 ----------------------------------------------
                                 Name: Christopher C. Cambria
                                 Title: Vice President-General Counsel and
                                        Secretary


                             HYGIENETICS ENVIRONMENTAL SERVICES, INC.


                             By: /s/ Christopher C. Cambria
                                 ----------------------------------------------
                                 Name: Christopher C. Cambria
                                 Title: Vice President and Secretary


                             L-3 COMMUNICATIONS ILEX SYSTEMS, INC.


                             By: /s/ Christopher C. Cambria
                                 ----------------------------------------------
                                 Name: Christopher C. Cambria
                                 Title:  Vice President and Secretary


                             L-3 COMMUNICATIONS SPD TECHNOLOGIES INC.


                             By:  /s/ Christopher C. Cambria
                                 ----------------------------------------------
                                 Name: Christopher C. Cambria
                                 Title:  Vice President and Secretary





    [GUARANTORS' ACKNOWLEDGMENT AND CONSENT TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]

<PAGE>




                                 L-3 COMMUNICATIONS AYDIN
                                 CORPORATION


                                 By:/s/ Christopher C. Cambria
                                 ----------------------------------------------
                                    Name:  Christopher C. Cambria
                                    Title:    Vice President and Secretary


                                 MICRODYNE CORPORATION


                                 By:/s/ Christopher C. Cambria
                                 ----------------------------------------------
                                     Name: Christopher C. Cambria
                                     Title:  Vice President and Secretary








    [GUARANTORS' ACKNOWLEDGMENT AND CONSENT TO CONSENT AND THIRD AMENDMENT TO
                 AMENDED AND RESTATED 364-DAY CREDIT AGREEMENT]