X0306 4 2022-05-19 0 0001260221 TransDigm Group INC TDG 0001234544 SMALL ROBERT J C/O BERKSHIRE PARTNERS LLC 200 CLARENDON STREET, 35TH FLOOR BOSTON MA 02116 1 0 0 0 Common Stock 2022-05-23 4 P 0 3611 560.71 A 188697 I By Stockbridge Partners LLC Common Stock 2022-05-23 4 P 0 895 560.71 A 2411175 I By Berkshire Entities Common Stock 2022-05-23 4 P 0 396 561.04 A 189093 I By Stockbridge Partners LLC Common Stock 2022-05-23 4 P 0 98 561.04 A 2411273 I By Berkshire Entities Common Stock 2022-05-23 4 P 0 80 563.02 A 189173 I By Stockbridge Partners LLC Common Stock 2022-05-23 4 P 0 20 563.02 A 2411293 I By Berkshire Entities Common Stock 2022-05-23 4 P 0 547 563.36 A 189720 I By Stockbridge Partners LLC Common Stock 2022-05-23 4 P 0 135 563.36 A 2411428 I By Berkshire Entities Common Stock 2022-05-23 4 P 0 2003 564.90 A 191723 I By Stockbridge Partners LLC Common Stock 2022-05-23 4 P 0 497 564.90 A 2411925 I By Berkshire Entities Common Stock 2022-05-23 4 P 0 5019 565.52 A 196742 I By Stockbridge Partners LLC Common Stock 2022-05-23 4 P 0 1244 565.52 A 2413169 I By Berkshire Entities Common Stock 2022-05-23 4 P 0 10986 566.39 A 207728 I By Stockbridge Partners LLC Common Stock 2022-05-23 4 P 0 2722 566.39 A 2415891 I By Berkshire Entities Common Stock 2022-05-23 4 P 0 160 567.06 A 207888 I By Stockbridge Partners LLC Common Stock 2022-05-23 4 P 0 40 567.06 A 2415931 I By Berkshire Entities Common Stock 40574 I By Family Trusts Common Stock 31970 I By Trust Common Stock 28902 D 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. Represents shares held directly or indirectly by Berkshire Fund VIII, L.P. ("VIII"), Berkshire Fund VIII-A, L.P. ("VIII-A"), Berkshire Fund IX, L.P. ("IX"), Berkshire Fund IX-A, L.P. ("IX-A"), Berkshire Investors III LLC ("Investors III"), Berkshire Investors IV LLC ("Investors IV") and Stockbridge Fund, L.P. ("SF") (collectively, the "Berkshire Entities"). Berkshire Partners Holdings LLC ("BPH") is the general partner of BPSP, L.P. ("BPSP"), which is the managing member of each of Berkshire Partners LLC, the registered investment adviser to VIII, VIII-A, IX, IX-A, Investors III and Investors IV ("BP"), and SP, the registered investment adviser to SF. Eighth Berkshire Associates LLC ("8BA") is the general partner of each of VIII and VIII-A. Ninth Berkshire Associates LLC ("9BA") is the general partner of each of IX and IX-A. [Continued from Footnote 2] Stockbridge Associates LLC ("SA") is the general partner of SF. The Reporting Person is a managing member of each of BPH, BPSP, BP, SP, 8BA, 9BA, SA, Investors III and Investors IV. 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 the Berkshire Entities. 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. Represents shares of Common Stock beneficially owned by certain family trusts. The Reporting Person is a trustee and the Reporting Person's immediate family members are beneficiaries of such family trusts. Represents shares of Common Stock beneficially owned by a trust. The Reporting Person is a trustee and the Reporting Person's immediate family members are beneficiaries of such trust. Represents shares of Common Stock held directly by the Reporting Person. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions within the range of $560.03 to $561.0299. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions within the range of $561.03 to $562.0299. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions within the range of $562.03 to $563.0299. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions within the range of $563.03 to $564.0299. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions within the range of $564.03 to $565.0299. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions within the range of $565.03 to $566.0299. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions within the range of $566.03 to $567.0299. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote. The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions within the range of $567.03 to $567.08. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote. Part 2 of 2. /s/ Robert J. Small 2022-05-23