Exhibit 4.9. FIRST AMENDMENT FIRST AMENDMENT (this "Amendment"), dated as of December 10, 1998, among TRANSDIGM HOLDING COMPANY, a Delaware corporation ("Holdings"), TRANSDIGM INC., a Delaware corporation (the "Borrower"), the lenders party to the Credit Agreement referred to below on the date hereof and immediately before giving effect to this Amendment (the "Existing Lenders"), BANKERS TRUST COMPANY, as Administrative Agent (the "Administrative Agent"), and each of the lenders listed on Schedule A hereto (the "New Lenders"). All capitalized terms used herein and not otherwise defined shall have the respective meanings provided such terms in the Credit Agreement referred to below. W I T N E S S E T H : WHEREAS, Holdings, the Borrower, the Existing Lenders and the Agent are parties to a Credit Agreement, dated as of December 3, 1998 (the "Credit Agreement"); and WHEREAS, the parties hereto wish to amend the Credit Agreement as herein provided; NOW, THEREFORE, it is agreed: 1. Each of the Existing Lenders severally and not jointly hereby sells and assigns to each of the New Lenders without recourse and without representation or warranty (other than as expressly provided herein), and each New Lender hereby purchases and assumes from each of the Existing Lenders, that interest in and to each of such Existing Lender's rights and obligations in respect of those Tranches of Loans set forth on Schedule B hereto under the Credit Agreement as of the date hereof which in the aggregate represents such New Lender's PRO RATA share (for each such New Lender, its "Pro Rata Share") in such Tranches of Loans as set forth on such Schedule B (calculated after giving effect to this Amendment), and such Pro Rata Share represents all of the outstanding rights and obligations under the Credit Agreement in respect of the Tranches of Loans that are being sold and assigned to each New Lender pursuant to this Amendment, including, without limitation, in the case of any assignment of outstanding A Term Loans, B Term Loans and/or portion of the Total Revolving Loan Commitment, all rights and obligations with respect to such New Lender's Pro Rata Share of such outstanding A Term Loans, B Term Loans and/or portion of the Total Revolving Loan Commitment, respectively. After giving effect to this Amendment, each Lender's outstanding A Term Loans, B Term Loans and Revolving Loan Commitment will be as set forth on Schedule C hereto. 2. In accordance with the requirements of Section 13.04(b) of the Credit Agreement, on the First Amendment Effective Date (as defined below), (i) the Credit Agreement shall be amended by deleting Annex I thereto in its entirety and by inserting in lieu thereof a new Annex I in the form of Schedule C hereto and (ii) the Borrower agrees that it will issue an appropriate A Term Note, B Term Note and Revolving Note, as applicable, to each Lender who so requests such Note or Notes in conformity with the requirements of Section 1.05 of the Credit Agreement. 3. On and after the First Amendment Effective Date, Annex II to the Credit Agreement shall be amended by deleting such Annex in its entirety and inserting in lieu thereof a new Annex II in the form of Schedule D hereto. 4. Each Existing Lender (i) represents and warrants that it is the legal and beneficial owner of the interest being assigned by it hereunder and that such interest is free and clear of any adverse claim; (ii) makes no representation or warranty and assumes no responsibility with respect to any statements, warranties or representations made in or in connection with the Credit Agreement or the other Credit Documents or the execution, legality, validity, enforceability, genuineness, sufficiency or value of the Credit Agreement or the other Credit Documents or any other instrument or document furnished pursuant thereto; and (iii) makes no representation or warranty and assumes no responsibility with respect to the financial condition of Holdings or any of its Subsidiaries or the performance or observance by Holdings or any of its Subsidiaries of any of their obligations under the Credit Agreement or the other Credit Documents to which any such Person is a party or any other instrument or document furnished pursuant thereto. 5. Each New Lender (i) confirms that it has received a copy of the Credit Agreement and the other Credit Documents, together with copies of the financial statements referred to therein and such other documents and information as it has deemed appropriate to make its own credit analysis and decision to enter into this Amendment; (ii) agrees that it will, independently and without reliance upon the Agent or any other Lender and based on such documents and information as it shall deem appropriate at the time, continue to make its own credit decisions in taking or not taking action under the Credit Agreement; (iii) confirms that it is an Eligible Transferee under Section 13.04(b) of the Credit Agreement; (iv) appoints and authorizes the Administrative Agent and the Collateral Agent to take such action as agent on its behalf and to exercise such powers under the Credit Agreement and the other Credit Documents as are delegated to the Administrative Agent and the Collateral Agent by the terms thereof, together with such powers as are reasonably incidental thereto; (v) agrees that it will perform in accordance with their terms all of the obligations which by the terms of the Credit Agreement are required to be performed by it as a Lender; and (vi) to the extent legally entitled to do so, agrees to promptly submit the forms described in Section 13.04(b) of the Credit Agreement. 6. Each of the Existing Lenders, the New Lenders and the Administrative Agent hereby agree that (A) all amounts accrued with respect to the A Term Loans, B Term Loans, outstanding Revolving Loans and the Total Unutilized Revolving Loan Commitment prior to the delivery by such New Lender of the amount referred to in clause (ii) of Section 11 of this Amendment shall be for the account of the Existing Lenders, respectively, and that all such amounts accrued on and after the delivery of such amounts referred to in clause (ii) of such Section 11 shall be for the account of such New Lender based upon its relevant Pro Rata Share and (B) the Documentation Agent shall not have any duties under the Credit Documents other than in its capacity as a Lender except as may be specifically assigned from time to time after the First Amendment Effective Date with the consent of the Documentation Agent. 7. In accordance with Section 13.04(b) of the Credit Agreement, on and as of the date upon which each of the New Lenders delivers the amounts referred to in clause (ii) of Section 11 of this Amendment, each New Lender shall become a "Lender" under, and for all purposes of, the Credit Agreement and the other Credit Documents and the Administrative Agent shall record the transfers contemplated hereby in the Register. 8. This Amendment is limited as specified and shall not constitute a modification, acceptance or waiver of any other provision of the Credit Agreement or any other Credit Document. 9. This Amendment may be executed in any number of counterparts and by the different parties hereto on separate counterparts, each of which counterparts when executed and delivered shall be an original, but all of which shall together constitute one and the same instrument. A complete set of counterparts shall be lodged with the Borrower and the Agent. 10. THIS AMENDMENT AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE LAW OF THE STATE OF NEW YORK. 11. Subject to Section 12 of this Amendment, this Amendment shall become effective on the date (the "First Amendment Effective Date") when (i) Holdings, the Borrower, the Administrative Agent, each Existing Lender and each New Lender shall have signed a counterpart hereof (whether the same or different counterparts) and shall have delivered (including by way of facsimile transmission) the same to the Administrative Agent at the Notice Office and (ii) each New Lender shall have delivered to the Administrative Agent, for the respective accounts of the Existing Lenders, an amount equal to such New Lender's relevant Pro Rata Share of the outstanding A Term Loans, B Term Loans and/or Revolving Loans being assigned to such New Lender. 12. Notwithstanding Section 11 of this Amendment, if for any reason any New Lender shall not have (i) signed a counterpart hereof and delivered the same to the Administrative Agent at the Notice Office and (ii) delivered to the Administrative Agent an amount equal to such New Lender's relevant Pro Rata Share of the outstanding A Term Loans, B Term Loans and/or Revolving Loans being assigned to such New Lender, in each case on or prior to December 10, 1998, then, if each Existing Lender agrees, this Amendment shall become effective notwithstanding such failure, provided that (x) Schedule C shall be modified to delete any such New Lender and such New Lender's relevant Pro Rata Share shall be reallocated among the Existing Lenders in such manner as the Existing Lenders shall agree and (y) the signature pages of this Amendment shall be deemed revised to delete such New Lender's name therefrom. 13. From and after the First Amendment Effective Date, all references in the Credit Agreement and each of the Credit Documents to the Credit Agreement shall be deemed to be references to the Credit Agreement as amended hereby. * * * IN WITNESS WHEREOF, each of the parties hereto has caused a counterpart of this Amendment to be duly executed and delivered as of the date first above written. TRANSDIGM HOLDING COMPANY By ------------------------------------- Title: TRANSDIGM INC. By ------------------------------------- Title: BANKERS TRUST COMPANY, Individually and as Administrative Agent By ------------------------------------- Title: CREDIT SUISSE FIRST BOSTON, Individually and as Syndication Agent By ------------------------------------- Title: By: ------------------------------------- Title: NEW LENDERS: BANK OF NOVA SCOTIA By ------------------------------------- Title: FLEET NATIONAL BANK, Individually and as Documentation Agent By ------------------------------------- Title: NBD BANK By ------------------------------------- Title: GENERAL ELECTRIC CAPITAL CORPORATION By ------------------------------------- Title: HELLER FINANCIAL, INC. By ------------------------------------- Title: NATIONAL CITY BANK By ------------------------------------- Title: -5- FIRST DOMINION CAPITAL By ------------------------------------- Title: INDOSUEZ CAPITAL FUNDING II A, LIMITED By ------------------------------------- Title: INDOSUEZ CAPITAL FUNDING IV, L.P. By: ------------------------------------- Title: PARIBAS CAPITAL FUNDING LLC By: ------------------------------------- Title: SANKATY HIGH YIELD ASSET PARTNERS, L.P. By ------------------------------------- Title: -6- Schedule A to FIRST AMENDMENT NEW LENDERS Bank of Nova Scotia Fleet National Bank NBD Bank General Electric Capital Corporation Heller Financial, Inc. National City Bank Indosuez Capital Funding Paribas Capital LLC Sankaty High Yield Asset Partners, L.P. SCHEDULE B to FIRST AMENDMENT RELEVANT PERCENTAGES LENDER A TERM LOANS B TERM LOANS REVOLVING LOANS - ------ ------------ ------------ --------------- Bankers Trust Company 17.05% 20.02777777778% 17.05% Credit Suisse First Boston 13.95% 2.75% 13.95% Bank of Nova Scotia 13.333333333% 13.33333333333% Fleet National Bank 9.166666667% 9.166666666667% 9.166666666667% NBD Bank 13.333333333% 13.33333333333% General Electric Capital Corporation 9.166666667% 9.166666666667% 9.166666666667% Heller Financial, Inc. 12% 4.444444444444% 12% National City Bank 12% 4.444444444444% 12% Indosuez Capital Funding II A, Limited 8.333333333333% Indosuez Capital Funding IV, L.P. 8.333333333333% Paribas Capital 16.66666666667% Sankaty High Yield 16.66666666667% Schedule C to FIRST AMENDMENT COMMITMENTS Outstanding Outstanding Outstanding LENDER A TERM LOANS B TERM LOANS REVOLVING LOANS - ------ ------------- ------------ --------------- Bankers Trust Company $7,672,500 $ 9,012,500 $5,115,000 Credit Suisse First Boston $6,277,500 $1,237,500 $4,185,000 Bank of Nova Scotia $6,000,000 $0 $4,000,000 Fleet National Bank $4,125,000 $4,125,000 $2,750,000 NBD Bank $6,000,000 $0 $4,000,000 General Electric Capital Corporation $4,125,000 $4,125,000 $2,750,000 Heller Financial Inc. $5,400,000 $2,000,000 $3,600,000 National City Bank $5,400,000 $2,000,000 $3,600,000 Indosuez Capital Funding II A, Limited $0 $3,750,000 $0 Indosuez Capital Funding IV, L.P. $0 $3,750,000 $0 Paribas Capital LLC $0 7,500,000 $0 Sankaty High Yield Asset Partners, L.P. $0 7,500,000 $0 Total: $45,000,000 $45,000,000 $30,000,000 Schedule D to FIRST AMENDMENT LENDER ADDRESSES BANKERS TRUST COMPANY 130 Liberty Street New York, NY 10006 Attention: Greg Shefrin Telephone No.: (212) 250-1724 Facsimile No.: (212) 250-7218 CREDIT SUISSE FIRST BOSTON 11 Madison Avenue New York, NY 10010 Attention: Bill O'Daly Telephone No.: (212) 325-9909 Facsimile No.: (212) 325-8388 BANK OF NOVA SCOTIA One Liberty Plaza New York, NY 10006 Attention: Robert Gaviglio Telephone No.: (212) 225-5054 Facsimile No.: (212) 225-5090 FLEET BANK One Federal Street Mail Stop: MA OF D03C Boston, MA 02110 Attention: Jim Silva Telephone No.: (617) 346-4399 Facsimile No.: (617) 346-4806 NBD BANK 611 Woodward Street Detroit, MI 48226 Attention: Paul DeMelo Telephone No.: (313) 225-2520 Facsimile No.: (313) 225-1212 GE CAPITAL CORPORATION 335 Madison Avenue New York, NY 10017 Attention: Kenneth Li Telephone No.: (212) 370-8040 Facsimile No.: (212) 983-8767 HELLER FINANCIAL INC. 500 West Monroe Street Chicago, IL 60661 Attention: Linda Wolf Telephone No.: (312) 441-7894 Facsimile No.: (312) 441-7357 Schedule D Page 2 NATIONAL CITY BANK 1900 East North Street 7th Floor Cleveland, OH 44114 Attention: Joseph Robinson Telephone No.: (216) 575-9254 Facsimile No.: (216) 575-9396 INDOSUEZ CAPITAL FUNDING 1211 Avenue of the Americas New York, NY 10036 Attention: Maklikah Buchweitz Telephone No.: (212) 278-2213 Facsimile No.: (212) 278-2254 PARIBAS CAPITAL LLC 787 Seventh Avenue New York, NY 10019 Attention: Francois Gauvin Telephone No.: (212) 841-2548 Facsimile No.: (212) 841-2363 SANKATY HIGH YIELD ASSET PARTNERS, 2 Copley Place L.P. Boston, MA 02116 Attention: Diane Exter Telephone No.: (617) 572-3216 Facsimile No.: (617) 572-3274