[Form 4] TransDigm Group INC Insider Trading Activity

Rhea-AI Filing Summary

Robert J. Small, a director of TransDigm Group Inc. (TDG), received equity on 09/19/2025 as director compensation under the Director Share Plan. The Form 4 reports receipt of common stock in lieu of a semi-annual director fee, and after the transaction the Reporting Person directly beneficially owned 15,625 shares. The filing lists additional indirect holdings: 441,814 shares held by Stockbridge Fund, L.P., 83,419 shares held by Stockbridge Partners LLC (managed account), and 60,246 shares held by certain family trusts. The report was signed by an attorney-in-fact on 09/22/2025 and discloses that the stock receipt was based on fair market value per the Director Share Plan.

Positive

• Director received equity-based compensation under the Director Share Plan, aligning director remuneration with shareholder interests
• Complete ownership breakdown disclosed showing direct and indirect holdings, including amounts for Stockbridge Fund, Stockbridge Partners LLC, and family trusts

Negative

• None.

Insights

Financial Analyst

TL;DR: Routine director compensation converted to equity; direct holdings increased to 15,625 shares on 09/19/2025.

The Form 4 documents a non-derivative acquisition of TransDigm common stock by director Robert J. Small as payment of a semi-annual director fee under the Director Share Plan. The filing shows the transaction date (09/19/2025) and the resulting direct beneficial ownership of 15,625 shares. It also discloses significant indirect positions held through investment vehicles and family trusts totaling 585,479 shares across three entities, per the report. This is a standard disclosure of compensation and affiliated holdings; the filing does not include financial performance metrics or indications of trading for investment reasons.

Corporate Governance Expert

TL;DR: Disclosure is consistent with Section 16 requirements and describes stock-in-lieu director compensation.

The statement clarifies the Reporting Person's roles in related entities and provides the required disclaimers about beneficial ownership. It explicitly states the shares were received in lieu of a semi-annual director fee under the Director Share Plan and provides the ownership breakdown (direct and indirect). The filing is procedural and addresses related-party attribution matters; there are no governance actions, resignations, or changes in board status reported.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

SMALL ROBERT J

(Last) (First) (Middle)

C/O BERKSHIRE PARTNERS

200 CLARENDON STREET, 35TH FLOOR

(Street)

BOSTON MA 02116

(City) (State) (Zip)

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)

3. Date of Earliest Transaction (Month/Day/Year)
09/19/2025

4. If Amendment, Date of 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

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	09/19/2025		A		44(1)	A	$1,288.13	15,625	D
Common Stock								441,814	I	By Stockbridge Fund, L.P.(2)
Common Stock								83,419	I	By Stockbridge Partners LLC(3)
Common Stock								60,246	I	By Family Trusts(4)

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 Securities Underlying Derivative Security (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: 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

Explanation of Responses:

1. Receipt of stock in lieu of payment of semi-annual director fee, based on fair market value in accordance with the Director Share Plan.

2. Represents shares held by Stockbridge Fund, L.P. ("SF"). Berkshire Partners Holdings LLC ("BPH") is the general partner of BPSP, L.P. ("BPSP"), which is the managing member of SP, the registered investment adviser to SF. Stockbridge Associates LLC ("SA") is the general partner of SF. The Reporting Person is a managing member of each of BPH, BPSP, SP and SA. As such, the Reporting Person may be deemed to share voting and dispositive power with respect to the shares of the Issuer's common stock held by SF. However, the Reporting Person disclaims beneficial ownership of these shares, except to the extent, if any, of his pecuniary interest therein, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 or for any other purposes.

3. Represents shares held by SP on behalf of a managed account over which it has shared voting and sole dispositive power. This Form 4 has been filed because the Reporting Person is a director of the Issuer and a managing member of SP. As such, the Reporting Person may be deemed to share voting and dispositive power with respect to the shares of the Issuer's common stock held by SP. However, the Reporting Person disclaims beneficial ownership of these shares, except to the extent, if any, of his pecuniary interest therein, and the inclusion of these securities in this report shall not be deemed an admission of beneficial ownership of the reported securities for purposes of Section 16 or for any other purposes.

4. Represents shares of Common Stock beneficially owned by certain family trusts. The Reporting person's immediate family members are beneficiaries of such family trust.

	/s/ Gabrielle Feuer as attorney-in-fact	09/22/2025
	** 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 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).
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 Number.

FAQ

What transaction did the Form 4 for TDG report?

The Form 4 reports the receipt of common stock by director Robert J. Small on 09/19/2025 as payment in lieu of a semi-annual director fee under the Director Share Plan.

How many shares does Robert J. Small directly own after the reported transaction?

After the reported transaction the Form 4 shows 15,625 shares beneficially owned directly by the Reporting Person.

What indirect holdings are disclosed in the Form 4 for TDG?

The filing discloses indirect holdings of 441,814 shares (Stockbridge Fund, L.P.), 83,419 shares (Stockbridge Partners LLC/managed account), and 60,246 shares (family trusts).

When was the Form 4 signed and filed?

The filing shows the signature by an attorney-in-fact on 09/22/2025 and the transaction date of 09/19/2025.

Was this transaction a sale or acquisition?

This transaction was an acquisition of common stock (receipt of shares) as director compensation, not a sale.