Piper PA-32-300 N4466T accident near Bethel, Alaska

Probable cause

A total loss of engine power due to a fatigue failure of the crankshaft. A contributing factor was the inadequate inspection during the engine’s last overhaul.

NTSB analysis

The pilot reported that, while in cruise flight, the engine lost partial power, then total power, and the propeller stopped turning.

During the subsequent off-airport forced landing on the tundra meadow, the main landing gear separated from the airplane, resulting in substantial damage to the right wing.

Examination of the engine revealed a crankshaft failure that was likely a result of fatigue cracking that emanated from the surface of the main journal.

The engine was overhauled at a certified repair station about 14 flight hours before the accident. The engine manufacturer overhaul manual stated that the crankshaft was to be inspected using a magnetic particle inspection procedure as part of the overhaul; however, the crankshaft was not inspected as part of the overhaul. It is likely that if the crankshaft had been inspected as indicated, the fatigue cracking would have been detected and corrected during overhaul.

Text from the NTSB. Open the NTSB docket for ANC19LA016 for the full record.