What happened
Shortly after takeoff, the pilot noticed that the oil pressure was decreasing. In an attempt to return to the departure airport, the pilot initiated a turn; however, the engine failed during the maneuver. The aircraft subsequently crashed into a lake located near the airport.
The investigation
Following the recovery of the aircraft, investigators examined the engine and discovered that an oil hose, which runs from the oil pump to the oil cooler inlet, had failed in two locations inside its protective fire sleeve. This fire sleeve was found to be soaked in oil and contained metal particles internally. Records indicated the failed hose was manufactured in the third quarter of 1987 and had been installed during an engine overhaul on July 22, 1987.
Further inspection of the engine revealed that three of the six cylinder connecting rods had failed because of a lack of lubrication. The remaining three connecting rods showed evidence of heat distress, and their associated rod bearings were found to be extruded. A review of the engine logbook showed the engine had been in operation for approximately 53 hours since its last inspection in November 1994.