=== SEC Form 4 — Statement of Changes in Beneficial Ownership ===
Document Type: 4
Period of Report: 2026-02-25
10b5-1 Pre-arranged Plan: No
--- Issuer ---
Name: TransDigm Group INC (TDG)
CIK: 0001260221
--- Reporting Owner ---
Name: SMALL ROBERT J
CIK: 0001234544
Role: Director
--- Non-Derivative Transactions ---
[Transaction #1]
Security: Common Stock
Date: 2026-02-25 | Code: P (Open market purchase)
Shares: +1 | Price: $1,285.00
Total Value: $1,285.00
Shares Owned After: 366,142 | Ownership: I (Indirect) | Nature: By Stockbridge Fund, L.P.
Footnotes:
[F1] The purchase of the Issuer's common stock reported herein was matchable under Section 16(b) of the Securities Exchange Act of 1934, to the extent of one (1) share, with the sale of one (1) share of the Issuer's common stock at a price of $1,335.72 per share by an entity in which the Reporting Person has a pecuniary interest. The Reporting Person has paid to the Issuer an amount representing the difference between the purchase and sale prices of the two transactions with respect to such one share of the Issuer's common stock.
[F2] 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.
--- Holdings ---
[Holding #1]
Security: Common Stock
Ownership: I (Indirect)
Footnotes:
[F3] Represents shares held by Stockbridge Partners LLC ("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.
[Holding #2]
Security: Common Stock
Ownership: I (Indirect)
Footnotes:
[F4] Represents shares of Common Stock beneficially owned by certain family trusts. The Reporting Person's immediate family members are beneficiaries of such family trusts.
[Holding #3]
Security: Common Stock
Ownership: D (Direct)
--- Footnotes (Complete Index) ---
F1: The purchase of the Issuer's common stock reported herein was matchable under Section 16(b) of the Securities Exchange Act of 1934, to the extent of one (1) share, with the sale of one (1) share of the Issuer's common stock at a price of $1,335.72 per share by an entity in which the Reporting Person has a pecuniary interest. The Reporting Person has paid to the Issuer an amount representing the difference between the purchase and sale prices of the two transactions with respect to such one share of the Issuer's common stock.
F2: 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.
F3: Represents shares held by Stockbridge Partners LLC ("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.
F4: Represents shares of Common Stock beneficially owned by certain family trusts. The Reporting Person's immediate family members are beneficiaries of such family trusts.
--- Signature ---
/s/ /s/ Robert J. Small (2026-02-27)
