EXHIBIT 10.31

                       AMENDMENT NO. 1 TO CREDIT AGREEMENT

         This AMENDMENT NO. 1 TO CREDIT AGREEMENT (the "Amendment") is made and
entered as of the 30th day of July, 1998, by and among HEICO CORPORATION, a
Florida corporation (together with its successors and permitted assigns,
"Borrower"), the lenders which are or may in the future be listed on the
signature pages to the Credit Agreement (as hereinafter defined) and hereto
(together with their successors and permitted assigns, individually a "Lender"
and collectively, the "Lenders"), and SUNTRUST BANK, SOUTH FLORIDA, NATIONAL
ASSOCIATION, as agent for the Lenders (together with any successor agent
appointed pursuant to the provisions herein, the "Agent").

                                   BACKGROUND

         The Borrower, the Lenders and the Agent are parties to a Credit
Agreement dated as of July 30, 1998 (the "Credit Agreement") and all of the
parties now desire to amend the Credit Agreement as provided herein.

         NOW, THEREFORE, in consideration of the premises and the mutual
agreements, covenants, and conditions herein, Borrower, the Lenders, and Agent
agree as follows:

         1. SECTION 1.1 (DEFINED TERMS) of the Credit Agreement shall be amended
by adding thereto the following definition:

            "DOCUMENTATION AGENT" shall mean First Union National Bank.

         2. SECTION 1.1 (DEFINED TERMS) of the Credit Agreement shall be amended
in the paragraph thereof defining "Guarantors" by deleting the word "and" before
the words "PTM Acquisition Corporation, a Florida corporation", and by adding
immediately after such words and immediately before the words "as to all of the
Obligations (as herein defined)", the words: "and McClain International, Inc., a
Georgia corporation".

         3. SECTION 2.7 (REVOLVING CREDIT TERMINATION DATE) of the Credit
Agreement shall be amended to read in its entirety as follows:

                           (a) REVOLVING CREDIT TERMINATION DATE; REQUEST FOR
                  EXTENSION. "All Borrowings outstanding under the Revolving
                  Credit Facility shall be due and payable in full on the
                  Revolving Credit Termination Date. The Borrower shall not
                  request and the Lenders will not be required to make or
                  consider requests for Revolving Credit Advances after the
                  Revolving Credit Termination Date. The Borrower may, by
                  written notice to the Agent (which shall promptly deliver a
                  copy to each of the Lenders), given not more than one hundred
                  twenty (120) days nor less than ninety (90) days prior to the
                  first anniversary date

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                  of the Closing Date, and again not more than one hundred
                  twenty (120) days nor less than ninety (90) days prior to the
                  second anniversary date of the Closing Date, request that the
                  Lenders extend the then scheduled Revolving Credit Termination
                  Date. Upon delivery of such notice by the Borrower, the
                  Lenders shall determine, in their sole and absolute
                  discretion, by decision of not less than all of the Lenders
                  (except as provided in paragraphs (b) and (c) of this Section
                  2.7), whether to extend the Revolving Credit Termination Date
                  for one (1) additional year on the same terms and conditions
                  as set forth in this Agreement, and Agent shall give written
                  notice to Borrower on or before the anniversary date of the
                  Closing Date prior to which such notice from the Borrower was
                  delivered, as to whether the Lenders have elected so to extend
                  the Revolving Credit Termination Date for one (1) additional
                  year.

                           (b) OPTIONS TO EXTEND REVOLVING CREDIT TERMINATION
                  DATE BY REPLACING NON-RENEWING LENDERS. In the event that
                  after delivery of a renewal notice by Borrower as provided in
                  paragraph (a) of this Section 2.7, one or more Lenders decide
                  not to extend the Revolving Credit Termination Date on the
                  first anniversary date of the Closing Date or on the second
                  anniversary date of the Closing Date, as the case may be, for
                  an additional one (1) year period, the Agent shall first offer
                  the Lenders who agree to extend the Revolving Credit
                  Termination Date the right to replace the non-renewing
                  Lender(s). Any such existing Lender(s) who agree to replace
                  the non-renewing Lender(s) shall assume all of the rights and
                  obligations of the non-renewing Lender(s) hereunder as of the
                  first or second anniversary date of the Closing Date, as the
                  case may be, pursuant to Section 13.17 of this Agreement and
                  one or more Assignment and Assumption Agreements as provided
                  therein. In its renewal notice delivered to Agent pursuant to
                  paragraph (a) of this Section 2.7, Borrower will have the
                  right to designate proposed new lender(s) to replace any
                  non-renewing Lender(s), and if the extension is not
                  accomplished in the manner set forth in the preceding
                  sentence, then if such designated new lender(s) are acceptable
                  to the Agent and agree(s) to become a party to this Agreement
                  as Lender(s) hereunder, then as of the first or second
                  anniversary date of the Closing Date, as the case may be, the
                  non-renewing Lender(s) shall assign all of its or their rights
                  and obligations under this Agreement to such designated new
                  lender(s), who shall assume all of such rights and
                  obligations, pursuant to Section 13.17 of this Agreement and
                  one or more Assignment and Assumption Agreements as provided
                  therein. Such new lender(s) shall thereby replace the
                  non-renewing Lender(s) as Lender(s) under and party to this

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                  Agreement and shall have all the rights and obligations of
                  such non-renewing assigning Lender(s) under the Loan Documents
                  to the same extent as if such new Lender(s) were original
                  parties thereto.

                           (c) OPTION TO PRE-PAY NON-RENEWING LENDERS AND EXTEND
                  REVOLVING CREDIT TERMINATION DATE AS TO REDUCED REVOLVING
                  CREDIT COMMITMENTS. In the event that after delivery of a
                  renewal notice by Borrower as provided in paragraph (a) of
                  this Section 2.7, the Required Lenders decide to extend, but
                  one or more Lenders decide not to extend, the Revolving Credit
                  Termination Date on the first anniversary date of the Closing
                  Date or on the second anniversary date of the Closing Date, as
                  the case may be, for an additional one (1) year period, and in
                  the event that pursuant to the provisions of Section 2.7(b)
                  all non-renewing Lenders are not replaced with existing
                  Lenders or new Lenders, the Borrower will have the right, if
                  so elected in writing in the renewal notice, to prepay, in
                  whole and not in part, and terminate the Revolving Credit
                  Commitments of the non-renewing Lenders who have not been so
                  replaced subject to the provisions of Section 2.10, except
                  that the provisions of Section 2.10(b)(i) shall not apply. The
                  Required Lenders who elected to extend may thereupon
                  unanimously extend the Revolving Credit Termination Date as to
                  the remaining aggregate Revolving Credit Commitments of such
                  Lenders for one (1) additional year.

                           (d) DOCUMENTATION FOR EXTENSIONS OF REVOLVING CREDIT
                  TERMINATION DATE. If all of the Lenders (including any such
                  new Lender(s) who become parties hereto pursuant to Section
                  2.7(b)), or the Required Lenders in the event of a pre-payment
                  and termination of the Revolving Credit Commitments of
                  non-renewing Lenders pursuant to Section 2.7(c), elect to make
                  any such extension of the Revolving Credit Termination Date,
                  assuming Borrower elects to accept such extension, Borrower,
                  at its expense, shall, and shall cause its Subsidiaries to,
                  execute such amendments to this Agreement and other documents
                  as shall be reasonably required by Agent on behalf of the
                  Lenders in connection with any such extension. Nothing
                  contained herein shall obligate the Lenders to make any such
                  extension of the Revolving Credit Termination Date."

         4. SECTION 2.10(B) (REDUCTION OF REVOLVING CREDIT COMMITMENTS) shall be
amended by deleting the "(c)" at the beginning of the first paragraph thereof,
and by adding at the beginning of subsection (i) thereof, the words: "Except as
provided in Section 2.7(c),".

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         5. SECTION 9.10 (HEICO AEROSPACE HOLDINGS CORP.) of the Credit
Agreement shall be amended by adding at the end thereof, the following language:

                  "Notwithstanding this Section 9.10, upon obtaining the prior
                  written consent of the Agent in each case on a case by case
                  basis, which consent shall not be unreasonably withheld, the
                  Borrower or the direct Subsidiaries of HEICO Aerospace
                  Holdings Corp. (i) may on the closing date of any Permitted
                  Acquisition made by HEICO Aerospace Holdings Corp. fund
                  through HEICO Aerospace Holdings Corp. the cash portion of the
                  acquisition purchase price to be paid at the closing of such
                  Permitted Acquisition, provided that Borrower shall cause
                  HEICO Aerospace Holdings Corp. to pay such cash acquisition
                  price immediately upon receipt of any such funds, such that no
                  such cash shall remain in HEICO Aerospace Holdings Corp. for
                  longer than twenty-four (24) hours, and (ii) no more
                  frequently than quarterly, may fund any payment of taxes
                  required to be made directly by HEICO Aerospace Holdings
                  Corp., provided that Borrower shall cause HEICO Aerospace
                  Holdings Corp. to pay such taxes immediately upon receipt of
                  any such funds, such that no cash remains in HEICO Aerospace
                  Holdings Corp. for longer than one (1) hour."

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

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                                 SIGNATURE PAGE

         Amendment No. 1 to Credit Agreement among HEICO Corporation, SunTrust
Bank, South Florida, National Association, as Agent, and the Lenders party
thereto.

Witness: HEICO CORPORATION,
                                  a Florida corporation

                                  By:
---------------------------          ---------------------------------
                                  Name: Thomas S. Irwin
                                  Title: Executive Vice President and
                                         Chief Financial Officer

                                                 (SEAL)

                                  Address:
                                          HEICO CORPORATION
                                          3000 Taft Street
                                          Hollywood, Florida 33021
                                          Attn: Thomas S. Irwin
                                                Executive Vice President and
                                                Chief Financial Officer
                                          Fax No. (954) 987-8228
                                          Confirming Tel. No. (954) 987-4000

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                                 SIGNATURE PAGE

         Amendment No. 1 to Credit Agreement among HEICO Corporation, SunTrust
Bank, South Florida, National Association, as Agent, and the Lenders party
thereto.

Witness: SUNTRUST BANK, SOUTH FLORIDA,
                                 NATIONAL ASSOCIATION
                                 a National Banking Association,
                                 as Agent

                                 By:
---------------------------         ---------------------------------
                                 Name: Dorman Parrish
                                 Title: Vice President


                                 Address of Lending Office for Notice:
                                          501 East Las Olas Boulevard, 7th Floor
                                          Corporate Banking Division
                                          Fort Lauderdale, Florida 33301
                                          Attn: Dorman Parrish
                                                   Vice President
                                                   Corporate Banking Division
                                          Fax No.  (954) 765-7301
                                          Confirming Tel. No. (954) 765-7311

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<PAGE>

                                 SIGNATURE PAGE

         Amendment No. 1 to Credit Agreement among HEICO Corporation, SunTrust
Bank, South Florida, National Association, as Agent, and the Lenders party
thereto.

Witness: SUNTRUST BANK, SOUTH FLORIDA,
                                 NATIONAL ASSOCIATION,
                                 a National Banking Association,
                                 as Lender

                                 By:
---------------------------         ---------------------------------
                                 Name: Dorman Parrish
                                 Title: Vice President


                                 Address of Lending Office for Notice:
                                          501 East Las Olas Boulevard, 7th Floor
                                          Corporate Banking Division
                                          Fort Lauderdale, Florida 33301
                                          Attn:    Dorman Parrish
                                                   Vice President
                                                   Corporate Banking Division
                                          Fax No.  (954) 765-7301
                                          Confirming Tel. No. (954) 765-7311


Revolving Credit Commitment:  $120,000,000.00

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