Incident Overview
Approximately 50 minutes after departure on a cross-country flight, the airplane's engine began to run roughly. The pilot observed a decrease in oil pressure, then heard a loud 'bang', followed by a total loss of engine power. Unable to maintain altitude, the pilot executed a forced landing to a field.
Mechanical Findings
Examination of the engine revealed a hole from detonation on the side of the #2 piston, which extended into the interior. Advisory Circular AC65-12A notes that detonation can burn a hole completely through a piston. Further inspection of the crankshaft showed a lack of lubrication and severe overheating. The #5 and #6 connecting rods had separated from the crankshaft, and their bearings were completely disintegrated.
No Other Details
No further information regarding the aircraft type, registration, number of occupants, or injuries was provided in the source.