Incident Overview
Shortly after takeoff, the pilot experienced a loss of engine power and executed a forced landing. Post-incident examination of the engine revealed a 1-inch by 6-inch hole in the engine crankcase adjacent to the number two cylinder, along with a fractured number two cylinder connecting rod.
Crankshaft Findings
The crankshaft installed in the engine required the installation of sludge tubes in the crank-pins. However, inspection showed that these sludge tubes had not been installed. According to a representative of the engine manufacturer, the crankshaft used was not approved for that specific engine model. The absence of the sludge tubes prevented pressurized oil from reaching the connecting rod bearings, which instead received only splash, vapor, and centrifugal force oil.
Maintenance History
The engine had accumulated approximately 940 hours of operation since its last overhaul on April 16, 1990. No logbook entries indicated that the crankshaft had been removed or replaced during that period.