- Initial Statement of Beneficial Ownership (3)

FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 Expires: November 30, 2011 Estimated average burden hours per response... 0.5
	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

1. Name and Address of Reporting Person ^*

Skulina James

2. Date of Event Requiring Statement (MM/DD/YYYY) 1/1/2012

3. Issuer Name and Ticker or Trading Symbol

TransDigm Group INC [TDG]

(Last) (First) (Middle)

1301 EAST NINTH STREET, SUITE 3000

4. Relationship of Reporting Person(s) to Issuer (Check all applicable)

_____ Director _____ 10% Owner
___ X ___ Officer (give title below) _____ Other (specify below)
Executive Vice President /

(Street)

CLEVELAND, OH 44114

(City) (State) (Zip)

5. If Amendment, Date Original Filed (MM/DD/YYYY)

6. Individual or Joint/Group Filing (Check Applicable Line)

_ X _ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

*Table II - Derivative Securities Beneficially Owned ( e.g.* , puts, calls, warrants, options, convertible securities)**
1. Title of Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivate Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security		6. Nature of Indirect Beneficial Ownership (Instr. 5)
Stock Option	7/22/2003	7/19/2012	Common Stock	71458	$3.35	D
Stock Option	8/5/2003	8/5/2013	Common Stock	59840	$6.68	D
Stock Option	9/30/2006	8/5/2013	Common Stock	239	$13.37	D
Stock Option	9/28/2005	7/19/2012	Common Stock	4966	$13.37	D
Stock Option	10/1/2005	10/1/2015	Common Stock	11968	$13.37	D
Stock Option	8/5/2003	8/5/2013	Common Stock	14960	$6.68	D
Stock Option	9/30/2006	8/5/2013	Common Stock	60	$13.37	D
Stock Option	9/28/2005	7/19/2012	Common Stock	1242	$13.37	D
Stock Option	10/1/2005	10/1/2015	Common Stock	2992	$13.37	D
Stock Option	9/30/2009	11/17/2018	Common Stock	35000	$27.08	D
Stock Option	9/30/2010	11/16/2019	Common Stock	10000	$41.79	D

Explanation of Responses:

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
Skulina James 1301 EAST NINTH STREET SUITE 3000 CLEVELAND, OH 44114			Executive Vice President

Signatures
/s/Halle Fine Terrion, as Attorney-in-Fact for James Skulina		1/6/2012
^** Signature of Reporting Person		Date

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
*	If the form is filed by more than one reporting person, see Instruction 5(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).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.