On April 11, 2019, at approximately 16:08 Alaska daylight time, a Piper PA-32-300, registration N4466T, was operating a Part 135 domestic passenger flight from Aniak Airport (ANI) to Bethel Airport (BET). While en route, the pilot noticed the engine sound changing and observed oil pressure dropping below the green arc. As the pilot attempted to divert to Akiak Airport (AKI), the engine RPM decreased and the engine eventually lost all power.
The pilot performed a forced landing in a tundra-covered meadow. During the impact, the main landing gear separated from the aircraft, causing substantial damage to the right wing. There were no injuries to the pilot or the three passengers on board.
Post-accident examination of the engine revealed that the unit had seized. Investigators found that the crankshaft had failed at the No. 3 main bearing journal. The fracture showed evidence of fatigue cracking originating from the surface of the main journal, along with thermal damage. The oil pan contained significant amounts of metal flakes and copper, and the oil pan screen contained heavily fragmented metal shavings.
The engine had been overhauled in April 2019 and had only accumulated approximately 14 hours of operation prior to the accident. While the engine overhaul work order indicated that inspections were completed, the investigation determined that the crankshaft had not undergone the required magnetic particle inspection specified in the Lycoming Overhaul Manual. The accident crankshaft lacked the NDT stamp used by the repair station to indicate completed non-destructive testing.