A B737-300 WAS DISPATCHED AND OPERATED FOR 3000 HRS IN NON COMPLIANCE WITH #2 ENG LOW PRESSURE TURBINE DISC BLADE RETAINER NOT INSTALLED.

Narrative

MAINT WAS PERFORMED AND DURING THE TIME AFTER THE LEAD CHK WAS PERFORMED THE LOW PRESSURE TURBINE DISC WAS PLACED ON A PIE CART FOR WAITING FOR THE OTHER 3 STAGES TO BUILD UP THE LOW PRESSURE TURBINE MODULE. DURING THIS TIME; MANY SHIFTS WENT BY AND WHEN THE AIR SEAL WAS INSTALLED; NO ONE SAW THAT THE BLADE RETAINER WAS NOW MISSING. NO PAPERWORK WAS ISSUED FOR A SECOND BUILD; AND THEREFORE MY SIGNATURE WAS ON THE JOB CARD; AND THE LEAD MECH ALSO VERIFIED AND SIGNED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE DEFECTIVE LOW PRESSURE TURBINE DISC WITH THE MISSING BLADE RETAINER WAS INSTALLED ON THE LOW PRESSURE TURBINE MODULE AND IN TURN ADDED TO A COMPLETE ENG. THE RPTR SAID THE ENG COMPLETED ALL RUN TESTS AND INSPECTIONS AND WAS INSTALLED ON AN AIRPLANE IN #2 ENG POS. THE RPTR SAID THE ENG OPERATED FOR 3000 HRS WHEN IT DEVELOPED A VIBRATION AND A BORESCOPE INSPECTION REVEALED LOW PRESSURE TURBINE DISC AND STATOR DAMAGE. THE RPTR STATED WHEN THE ENG WAS TORN DOWN IT WAS DISCOVERED THE TURBINE DISC MIGRATED AFT AND STARTED RUBBING ON THE STATOR VANES DUE TO THE BLADE RETAINER MISSING. THE RPTR STATED AFTER HE BUILT UP THE DISC AND THE LEAD TECHNICIAN MADE THE FINAL INSPECTION IT WAS ROUTED FOR DYNAMIC BALANCING. THE RPTR SAID AT THAT TIME THERE WAS NO JOB CARD FOR THE DYNAMIC BALANCING SEGMENT OF THE OP. THE RPTR STATED THE BALANCING REQUIRES SHUFFLING SOME BLADES AROUND ON THE DISC TO ACHIEVE BAL AND THIS IS WHERE THE RETAINER WAS LOST. THE RPTR SAID THE COMPANY INVESTIGATION HAS CORRECTED THIS SIT AND CLOSED THIS PAPERWORK GAP.