Circumstances:
After an uneventful flight to Tambar Springs, two passengers embarked for the return journey to Bankstown. Approaching Scone, unsuitable weather forced the pilot to divert east of track towards the coast. Whilst cruising at 1500 feet AMSL, about two kilometres north of Warnervale, the engine, without warning, suffered a complete loss of power. The pilot transmitted a Mayday call to Sydney Flight Service and positioned the aircraft for a straight-in approach onto runway 17 at Warnervale. He carried out a trouble check and attempted to restart the engine without success. The aircraft passed over the threshold high and fast and landed well down the runway. The pilot was unable to prevent the aircraft from running off the southern end and it came to rest some 150 metres beyond the runway after passing through a boundary fence which damaged both wings. A technical investigation revealed the complete engine failure occurred as a result of the disconnection of the accessory drive gear from the crankshaft. The locating dowl failed due to fatigue after a loss of tension of a bolt attaching the accessory drive gear to the crankshaft. The reason for the loss of tension was not positively established. However, it is possible that a propeller strike, 593 hours prior to the accident, caused the loss of initial torque on the bolt. The propeller strike and subsequent rectification action occurred in the United States of America before the aircraft was imported to Australia.
