What happened
During a flight traveling from Bethel toward Holy Cross, the pilot encountered significant mechanical issues involving the aircraft's engine. The engine experienced an overspeed event which subsequently led to total power loss. In response to the developing situation, the pilot lowered the altitude of the aircraft type to facilitate a safer descent. This maneuver resulted in an emergency landing on land near Paimiut. While the impact caused the aircraft to be damaged beyond repair, the pilot was able to exit the wreckage without any injuries.
Findings
Investigations into the accident identified that the engine failure occurred during the cruise phase of flight. The primary cause was linked to improper maintenance and inspection procedures performed by maintenance personnel. Specific mechanical issues discovered included a lack of lubrication in a particular component and material failure. Further technical details revealed that the number 4 main bearing had turned because the lubrication passages were not properly aligned, which also caused the crankcase halves to become loose. Additionally, the engine oil was found to be extremely dark and tarry. Other contributing elements noted during the investigation included an uncontrollable propeller overspeed due to governor issues, inadequate preflight preparations by the pilot, and the difficulty of landing on rough terrain.