X0202 3 2006-03-14 0 0001260221 TransDigm Group INC TDG 0001157334 WARBURG PINCUS PRIVATE EQUITY VIII L P C/O WARBURG PINCUS & CO. 466 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0000929408 WARBURG PINCUS & CO C/O WARBURG PINCUS & CO. 466 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001162870 WARBURG PINCUS LLC C/O WARBURG PINCUS & CO. 466 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 0001322709 Warburg Pincus Partners LLC C/O WARBURG PINCUS & CO. 466 LEXINGTON AVENUE NEW YORK NY 10017 0 0 1 0 Common Stock, par value $0.01 per share 30601875 D See Exhibit 99.1 - Explanation of Responses. WARBURG PINCUS PRIVATE EQUITY VIII, L.P. By: Warburg Pincus Partners LLC, General Partner By: Warburg Pincus & Co., Managing Member /s/ Kewsong Lee, Partner 2006-03-14