What happened
While climbing between 3,500 and 4,000 feet following takeoff, the pilot observed a decrease in engine oil pressure accompanied by an increase in oil temperature. The pilot notified air traffic control of the mechanical issue and was subsequently provided with radar vectors toward the nearest airport.
During the period of receiving vectors, the engine suffered a complete failure. As the engine failed, oil sprayed across the windshield and the pilot's side window, obstructing visibility. Due to the inability to see the airport, the pilot executed a forced landing into an open field, resulting in the aircraft impacting the ground.
The investigation
The engine involved in the accident had completed approximately 440 flight hours since its last manufacturer overhaul. Investigators determined that remanufactured connecting rods had been installed in the engine prior to the event.
Upon examination of the engine, investigators found that four of the six connecting rod bearings had melted at the crankshaft. Additionally, fatigue cracks were identified on the number four connecting rod and its end cap. When the retaining nuts for the connecting rod end cap were removed, evidence of moderate wear and fretting was discovered in the recesses where the nuts contacted the rods.