Ownership Submission
FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF 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 *
  McClelland Ralph
 2. Date of Event Requiring Statement (Month/Day/Year)
06/15/2006		 3. Issuer Name and Ticker or Trading Symbol
TransDigm Group INC [TDG]
(Last)
(First)
(Middle)
MARATHONNORCO AEROSPACE, INC., PO BOX 8233, 8301 IMPERIAL DRIVE		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Pres., MarathonNorco Aerospace
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

WACO, TX 76714-8233		 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 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)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(Month/Day/Year)		 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)
Date Exercisable Expiration Date Title Amount or Number of Shares
Stock Options (1) 09/30/2004 08/05/2013 Common Stock 47,872 $ 6.68 D  
Stock Options (2) 01/20/2004 08/05/2013 Common Stock 11,968 $ 6.68 D  
Stock Options (3) 09/30/2005 12/30/2014 Common Stock 11,968 $ 8.52 D  
Stock Options (4) 12/30/2004 12/30/2014 Common Stock 2,992 $ 8.52 D  
Stock Options (5) 09/30/2006 06/15/2016 Common Stock 64,000 $ 22.21 D  
Stock Options (6) 06/15/2006 06/15/2016 Common Stock 16,000 $ 22.21 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
McClelland Ralph
MARATHONNORCO AEROSPACE, INC.
PO BOX 8233, 8301 IMPERIAL DRIVE
WACO, TX 76714-8233		       Pres., MarathonNorco Aerospace  

Signatures

/s/ Deanna M. Campbell, Attorney-in-Fact for Ralph McClelland 06/23/2006
**Signature of Reporting Person Date

Explanation of Responses:

* 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).
(1) Vesting is based on achievement of annual and cumulative performance metrics; option is currently 41.62% vested and the remainder will vest at 7.30% in 2006, 7.30% in 2007, 7.29% in 2008 and 36.49% in 2008.
(2) Vests over time in 20% increments starting on grant date and annually on next four anniversary dates.
(3) Vesting is based on achievement of annual and cumulative performance metrics; option is currently 36.14% vested and the remainder will vest at 9.12% in 2006, 9.12% in 2007, 9.13% in 2008 and 36.49% in 2008.
(4) Vests over time in 25% increments starting on grant date and annually on next three anniversary dates.
(5) Vesting is based on achievement of annual and cumulative performance metrics at 16.66% for each year from 2006 to 2008, then at 50% in 2008.
(6) Vests over time in 33.33% increments starting on grant date and annually on next two anniversary dates.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, See Instruction 6 for procedure.

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