Incident Summary
A pilot was flying from Bethel to Holy Cross when the engine oversped and subsequently failed. The pilot descended and completed an emergency landing in Paimiut. The pilot escaped uninjured, but the airplane was damaged beyond repair.
Probable Cause and Contributing Factors
The official probable cause of the engine failure during normal cruise was inadequate maintenance and inspection on the part of the maintenance personnel. Contributing factors reported include: engine structure (other), lack of lubrication (specific part, not system), material failure, inadequate preflight preparation on the part of the pilot, propeller and accessories (governors), RPM-uncontrollable overspeed, rough terrain, complete engine power loss, forced landing off airport on land, N°4 main bearing turned (lube passages not aligned), crankcase halves loose, and oil that was very black and tarry.