Joinder Agreement



 Exhibit 10.4 
 EXECUTION COPY 
 JOINDER AGREEMENT 
 THIS JOINDER AGREEMENT (this “Agreement”), dated as of December 2, 2009, is entered into between DUKES AEROSPACE,
INC., a Delaware corporation (the “New Subsidiary”), and CREDIT SUISSE AG (formerly known as Credit Suisse), as Agent, under that certain Credit Agreement, dated as of June 23, 2006 (as the same may be amended, supplemented or
otherwise modified from time to time, the “Credit Agreement”), among TransDigm Inc., a Delaware corporation (the “Borrower”), TransDigm Group Incorporated, a Delaware corporation, the Subsidiaries of the Borrower
from time to time party thereto, the Lenders from time to time party thereto and the Agent, as amended by (i) that certain Amendment No. 1, Consent and Agreement dated as of January 25, 2007 and (ii) that certain Assumption
Agreement dated as of February 7, 2007. All capitalized terms used herein and not otherwise defined shall have the meanings set forth in the Credit Agreement. 
 The New Subsidiary and the Agent, for the benefit of the Lenders, hereby agree as follows: 
 1. The New Subsidiary hereby acknowledges, agrees and confirms that, by its execution of this Agreement, the New Subsidiary will be deemed to be a Loan Party under the Credit Agreement and a Loan
Guarantor for all purposes of the Credit Agreement and shall have all of the obligations of a Loan Party and a Loan Guarantor thereunder as if it had executed the Credit Agreement. The New Subsidiary hereby ratifies, as of the date hereof, and
agrees to be bound by, all of the terms, provisions and conditions contained in the Credit Agreement, including without limitation (a) all of the representations and warranties of the Loan Parties set forth in Article III of the Credit
Agreement (to the extent made or deemed made on or after the effective date hereof), (b) all of the covenants set forth in Articles V and VI of the Credit Agreement and (c) all of the guaranty obligations set forth in the Guarantee and
Collateral Agreement. Without limiting the generality of the foregoing terms of this paragraph 1, the New Subsidiary, subject to the limitations set forth in the Guarantee and Collateral Agreement, hereby absolutely and unconditionally guarantees,
jointly and severally with the other Loan Guarantors, to the Agent and the Lenders, the prompt payment of the Secured Obligations in full when due (whether at stated maturity, upon acceleration or otherwise) to the extent of and in accordance with
the Guarantee and Collateral Agreement. 
 2. If required, the New Subsidiary is, simultaneously with the execution of this
Agreement, executing and delivering such Collateral Documents (and such other documents and instruments) as requested by the Agent in accordance with the Credit Agreement, except for items listed on Schedule I hereto which will be executed and
delivered as soon as practical. 
 3. The New Subsidiary hereby waives acceptance by the Agent and the Lenders of the guaranty
by the New Subsidiary upon the execution of this Agreement by the New Subsidiary. 







 4. This Agreement may be executed in any number of counterparts, each of which when so
executed and delivered shall be an original, but all of which shall constitute one and the same instrument. 
 5. THIS AGREEMENT
AND THE RIGHTS AND OBLIGATIONS OF THE PARTIES HEREUNDER SHALL BE CONSTRUED IN ACCORDANCE WITH AND GOVERNED BY THE LAWS OF THE STATE OF NEW YORK. 
 [Remainder of page intentionally left blank] 







 IN WITNESS WHEREOF, the New Subsidiary has caused this Agreement to be duly executed by
their respective authorized officer, and the Agent, for the benefit of the Lenders, has caused the same to be accepted by its authorized officer, as of the day and year first above written. 
  

			
	 DUKES AEROSPACE, INC.

		
	 by
	 	 /s/ Gregory Rufus

		 	Name: Gregory Rufus
		 	Title: Secretary and Treasurer










			
	Acknowledged and accepted:
	
	CREDIT SUISSE AG,
	CAYMAN ISLANDS BRANCH (formerly known as
	Credit Suisse, Cayman Islands Branch), as Agent
		
	by	 	 /s/ Robert Hetu

		 	Name: Robert Hetu
		 	Title: Managing Director
		
	by	 	 /s/ Christopher Day

		 	Name: Christopher Day
		 	Title: Associate









 SCHEDULE I 
 ITEMS TO BE EXECUTED AND DELIVERED