Accident Overview
The pilot reported that the preflight inspection and engine run-up were conducted without any anomalies. Following takeoff, the airplane suffered a loss of engine power, leading to a descent and subsequent impact with terrain. The aircraft ended up inverted in a sewage pond near the airport.
Post-Accident Actions
After the power loss, the pilot attempted to restart the engine using the emergency checklist but was unsuccessful.
Engine Inspection Findings
An examination of the engine established mechanical continuity. The crankcase was separated, revealing heat discoloration on the bearings, pistons, and cylinders. The number 4 main bearing showed evidence of rubbing on the crankshaft, with a section of that bearing insert severely worn, heat distressed, and flowed over the edge of the crankcase bearing journal. The number 6 connecting rod bearing insert contained an unidentified metal substance in its oil port. The remaining crankcase oil journals were clear.
The oil pump was disassembled and exhibited a nick on one of the driven gear teeth, corresponding to circumferential scoring on the oil pump housing. The oil filter and suction screen were clean. No further discrepancies were noted with the engine.
Maintenance History
A review of maintenance records revealed that an annual inspection, which included an oil change, had been completed approximately one hour prior to the accident flight.