X0306 4 2019-02-26 0 0001260221 TransDigm Group INC TDG 0001298803 Dunn Mervin MERV DUNN MANAGEMENT & CONSULTING 22761 PACIFIC COAST HIGHWAY, SUITE 104 MALIBU CA 90265 1 0 0 0 Common Stock 2019-02-26 4 S 0 8944 432.2753 D 1119 D The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $432.00 to $432.77, inclusive. The reporting person undertakes to provide to the company, any security holder of the company or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes to this Form 4. In preparing this report, it was discovered that prior reports failed to include shares held by the reporting person in a joint account with his spouse. Following the reported transaction, no shares remain in the joint account. The company is continuing its due diligence to verify the reporting person's beneficial ownership, and, if necessary, will make corrective filings. Halle Fine Terrion as attorney in fact for Mervin Dunn 2019-02-28