Exhibit 10.1

AMENDMENT NO. 3

TO THE

TRANSDIGM GROUP INCORPORATED

FOURTH AMENDED AND RESTATED 2003 STOCK OPTION PLAN

WHEREAS, TransDigm Group Incorporated (the “Company”) currently maintains and
sponsors the TransDigm Group Incorporated Fourth Amended and Restated 2003 Stock
Option Plan (the “Plan”); and

WHEREAS, the Board of Directors of the Company (the “Board”) wishes to amend the
Plan in accordance with the provisions of Section 17.

NOW, THEREFORE, the Plan is hereby amended as follows:

1. Notwithstanding Sections 4(a), 7 and 8 of the Plan, all unissued New
Management Options and any forfeited Rollover Options or New Management Options
shall vest and become exercisable in such manner and on such date or dates set
forth in the Option Agreement, as may be determined by the Committee.

2. This Amendment No. 3 shall be effective as of April 23, 2009.

3. Except as modified by this Amendment No. 3, all of the terms and conditions
of the Plan shall remain valid and in full force and effect.

IN WITNESS WHEREOF, this Amendment No. 3 was duly adopted by the Board of
Directors as of April 23, 2009.

 

TRANSDIGM GROUP INCORPORATED By  

/s/ Gregory Rufus

  Gregory Rufus, Executive Vice President, Chief   Financial Officer and
Secretary