144 0001505183 XXXXXXXX LIVE 0001260221 TransDigm Group INC 001-32833 1350 Euclid Avenue, Suite 1600 Cleveland OH 44115 216-706-2960 Stockbridge Partners LLC May be deemed affiliate Common Stock Goldman, Sachs & Co.,

200 West Street New York NY 10282-2198

65000 95280250.00 56167085 06/10/2025 NYSE Common Stock Merrill Lynch, Pierce, Fenner & Smith Incorporated

4 World Center 250 Vesey Street New York NY 10080

65000 95280250.00 56167085 06/10/2025 NYSE Common Stock Morgan Stanley & Co. LLC

1585 Broadway New York NY 10036

65000 95280250.00 56167085 06/10/2025 NYSE Common Stock 12/06/2010 Open market purchases Open market purchases N 65000 12/06/2010 Cash N Stockbridge Partners LLC

200 Clarendon Street 35th Floor Boston MA 02116

Common Stock 03/13/2025 1000 1335218.90 Stockbridge Partners LLC

200 Clarendon Street 35th Floor Boston MA 02116

Common Stock 03/14/2025 9034 12115718.73 Stockbridge Partners LLC is deemed to be the beneficial owner of the Common Stock held through a separate managed account and through Stockbridge Fund, L.P. Regarding the "Securities To Be Sold" Table, the dates of acquisition and payment of the Common Stock varied, commencing on the date reported in the Table. Stockbridge Partners LLC is signing this form on behalf of the separate managed account and Stockbridge Fund, L.P. 06/10/2025 STOCKBRIDGE PARTNERS LLC, By: BPSP, L.P., its Managing Member, By: Berkshire Partners Holdings LLC, itsGeneral Partner, Kenneth S. Bring, its M.D.