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                                                                    EXHIBIT 12.3


                COMPUTATION OF RATIO OF PRO FORMA TRANSDIGM INC.
                         NET DEBT TO EBITDA (AS DEFINED)
                             (DOLLARS IN THOUSANDS)

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<Caption>

                                                      Pro Forma Twelve Months
                                                       Ended March 30, 2002

                                                        
TransDigm Inc. Net Debt                                    $   353,060
EBITDA (as defined)                                             90,171
                                                           -----------
      Ratio                                                      3.9
                                                           ===========
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