<ARTICLE> 5
<CIK> 0001077672
<NAME> TRANSDIGM HOLDING COMPANY
<MULTIPLIER> 1,000
       
                                                      
<PERIOD-TYPE>                   YEAR                        YEAR
<FISCAL-YEAR-END>                          SEP-30-1998                 SEP-30-1999
<PERIOD-END>                               SEP-30-1998                 JAN-01-1999
<CASH>                                          19,486                       2,103
<SECURITIES>                                         0                           0
<RECEIVABLES>                                   12,795                      14,681
<ALLOWANCES>                                       265                         278
<INVENTORY>                                     18,280                      18,180
<CURRENT-ASSETS>                                54,260                      46,370
<PP&E>                                          39,156                      39,867
<DEPRECIATION>                                  17,205                      18,158
<TOTAL-ASSETS>                                 115,785                     118,161
<CURRENT-LIABILITIES>                           37,606                      19,616
<BONDS>                                              0                           0
<PREFERRED-MANDATORY>                                0                           0
<PREFERRED>                                          0                           0
<COMMON>                                        24,281                     101,424
<OTHER-SE>                                      12,146                   (236,789)
<TOTAL-LIABILITY-AND-EQUITY>                   115,785                     118,161
<SALES>                                        110,868                      28,194
<TOTAL-REVENUES>                               110,868                      28,194
<CGS>                                           59,395                      14,937
<TOTAL-COSTS>                                   59,395                      14,937
<OTHER-EXPENSES>                                21,175                      43,371
<LOSS-PROVISION>                                     0                           0
<INTEREST-EXPENSE>                               3,175                       2,276
<INCOME-PRETAX>                                 27,123                    (32,390)
<INCOME-TAX>                                    12,986                     (7,566)
<INCOME-CONTINUING>                             14,137                    (24,824)
<DISCONTINUED>                                       0                           0
<EXTRAORDINARY>                                      0                           0
<CHANGES>                                            0                           0
<NET-INCOME>                                    14,137                    (24,824)
<EPS-PRIMARY>                                        0                           0
<EPS-DILUTED>                                        0                           0