Incident Overview
A Piper 32RT 300T aircraft made a forced landing onto a dirt strip near an automobile salvage yard after a total loss of engine power. During the landing, the airplane collided with a parked automobile. The pilot reported hearing a loud bang while cruising at 13,500 feet mean sea level (MSL) and subsequently observed oil obscuring the windshield. The engine was secured, and a dirt strip was selected as the landing area.
Examination Findings
Preliminary examination by safety board investigators identified a hole in the engine crankcase near the number 1 and number 2 cylinders. Further disassembly revealed that the connecting rods for cylinders number 1 and 2 were broken. The number 1 connecting rod exhibited a galled spot on its bearing surface. Inspection of the remaining five connecting rods showed evidence of galling between the connecting rod bearing face and the rod bearing.
Manufacturer's Input
According to the engine manufacturer, galling between the connecting rod bearing face and the rod bearing is caused by periods of high loading due to overspeed or excessive manifold pressure.
Maintenance History
Approximately 15 days or 6 flight hours before the incident, maintenance personnel had adjusted the turbocharger wastegate. The pilot stated that no unusual instrument indications were observed prior to the engine failure.