X0508 4 2026-02-02 0001260221 TransDigm Group INC TDG 0001431675 Stein Kevin M 1350 EUCLID AVE SUITE 1600 CLEVELAND OH 44115 true false false false true Common Stock 2026-02-02 4 M false 25000 341.28 A 33158 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 M false 23000 342.31 A 56158 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 40 1404.68 D 56118 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 218 1407.7647 D 55900 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 2 1409.71 D 55898 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 6 1410.9800 D 55892 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 1 1412.26 D 55891 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 175 1414.0434 D 55716 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 58 1414.3607 D 55658 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 52 1415.633 D 55606 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 2 1416.3950 D 55604 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 48 1417.4413 D 55556 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 112 1419.4320 D 55444 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 223 1420.5097 D 55221 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 861 1421.7299 D 54360 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 2141 1422.4759 D 52219 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 3997 1423.6631 D 48222 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 4859 1424.4675 D 43363 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 5906 1425.5736 D 37457 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 5665 1426.6062 D 31792 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 6665 1427.3841 D 25127 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 2067 1428.6442 D 23060 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 1810 1429.6133 D 21250 I Fortuna Trust dated June 1, 2018 Common Stock 2026-02-02 4 S false 2017 1430.2632 D 19233 I Fortuna Trust dated June 1, 2018 Stock Option. 342.31 2026-02-02 4 M false 23000 0 D 2025-09-30 2030-11-11 Common Stock 23000 20000 I Fortuna Trust dated June 1, 2018 Stock Option 341.28 2026-02-02 4 M false 25000 0 D 2023-09-30 2029-11-15 Common Stock 25000 17940 I Fortuna Trust dated June 1, 2018 The exercise price has been adjusted for dividends declared since August 1, 2022. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,407.1000 - $1,407.8900. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,410.9300 - $1,411.2300. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,413.3000 - $1,414.2900. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,414.3000 - $1,414.6900. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,415.3000 - $1,416.1000. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,416.3300 - $1,416.4600. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,417.4150 - $1,417.5900. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,418.8500 - $1,419.7000. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,420.0200 - $1,420.8800. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,421.0200 - $1,422.0100. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,422.0200 - $1,423.0100. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,423.0200 - $1,424.0100. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,424.0300 - $1,425.0200. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,425.0300 - $1,426.0200. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,426.0300 - $1,427.0100. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,427.0300 - $1,428.0200. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,428.0300 - $1,429.0200. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,429.0500 - $1,430.0400. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Price reported constitutes the average weighted price of shares sold. Shares were sold at varying prices in the range of $1,430.0500 - $1,431.0300. The reporting person hereby undertakes, upon request of the Commission, the issuer or a security holder of the issuer, to provide full information regarding the number of shares sold at each separate price. Due to a 30-line item limitation in Table 1, this is the first of two Form 4s filed by the reporting person for this transaction. /s/ Rachel Quinlan as attorney in fact for Kevin Stein 2026-02-03