What was found
ACFT PERFORMED AN UNSCHEDULED LANDING AT CUL DUE TO A PRESSURIZATION FAILURE; EMERGENCY PROCEDURE PERFORMED BEING NOT POSSIBLE TO CONTROL IT, PERFORMING AN EMERGENCY DESCENT TO 14,000 FT. DURING MX REVISION DETECTED A LEAK IN AFT SERVICE DOOR DUE TO SEAL DOOR REAR BOTTOM AREA IMPROPERLY INSTALLED (IN 3 INCHES LONG APPROXIMATELY), 90 PERCENT OF OXYGEN MASKS FOUND DEPLOYED WITH OXYGEN SYS SWITCH IN MANUAL MODE. SEAL DOOR PROPERLY INSTALLED IAW MM 52-42-02, TESTED CORRECT. ACFT FERRIED TO GDL. AT GDL, 79 CHEMICAL OXYGEN GENS REPLACED IAW MM 35-22-01, A/C SYS & PRESSURIZATION TESTS PERFORMED IAW MM 21-32-00, TESTED CORRECT. FDR REMOVED & ANALYZED AND RECORDS DEMONSTRATE THAT AIRCRAFT DID NOT DEPRESSURIZE.