What was found
(AUS) LH ENGINE REDUCTION GEARBOX FIRST STAGE PLANET GEAR CARRIER BOLT FAILED. INVESTIGATION FOUND THAT THE BOLT HEAD HAD SEPARATED AND ENTERED THE FIRST STAGE GEAR TRAIN. EXAMINATION OF THE CARRIER BOLTS REVEALED FOUR BOLTS FRACTURED IN THE THREADED AREA AND ONE BOLT FRACTURED UNDER THE BOLT HEAD. SUSPECT BOLTS OVERTORQUED DURING ASSEMBLY. PERSONNEL/MAINTENANCE ERROR. METAL CONTAMINATION OF ENGINE.