FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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(Print or Type Responses)

1. Name and Address of Reporting Person * BARR DAVID   2. Issuer Name and Ticker or Trading Symbol TransDigm Group INC [TDG] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) __X__ Director _____ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) 466 LEXINGTON AVENUE 3. Date of Earliest Transaction (Month/Day/Year) 03/23/2009 (Street) NY, NY 10017 4. If Amendment, Date Original Filed(Month/Day/Year) 6. Individual or Joint/Group Filing(Check Applicable Line) _X_ Form filed by One Reporting Person ___ Form filed by More than One Reporting Person (City) (State) (Zip) Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock, par value $0.01 per share (1) 03/23/2009   J(1)   1,351,183 D $ 0 (1) 7,332,018 I See footnote (1) Common Stock, par value $0.01 per share (2)               2,778 D   Common Stock, par value $0.01 per share               28,712 D   Common Stock (restricted), par value $0.01 per share (3)               787 D

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Stock Options (right to buy) (4)

$ 27.08

09/30/2009(4)

11/17/2018

Common Stock

15,900

15,900

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
BARR DAVID 466 LEXINGTON AVENUE NY, NY 10017	X

Signatures

David Barr by: Scott A. Arenare Attorney-In-Fact /s/ Scott A. Arenare		03/24/2009
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(b)(v).
**	Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1)	See Exhibit 99.1.
(2)	Receipt of stock in lieu of payment of semi-annual director fee, based on fair market value in accordance with the 2006 Stock Incentive Plan.
(3)	Receipt of stock in respect of annual grant of restricted stock to directors with the number of shares determined based on the fair market value of the stock on the date of grant. Subject to forfeiture; forfeiture provisions lapse as to one-third of the stock on each of the first, second and third anniversaries of the date of grant.
(4)	Vest based on the achievement of annual and cumulative per share operating performance targets between fiscal 2009 and fiscal 2013.

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