What happened
During the climb to cruise altitude following takeoff, the pilot noticed engine oil temperatures rising beyond the standard operating range. Consequently, a request was made to return to the departure airport. While the aircraft was being vectored for an instrument approach, smoke appeared within the cabin and the engine suffered a complete loss of power. The pilot was unable to reach a runway and instead performed a forced landing in a field. The impact caused substantial damage to the fuselage and wings.
Findings
Investigations into the engine revealed that only approximately 2 quarts of oil remained in the system, and the recovered oil contained metallic contamination. Evidence of an oil leak was identified within the engine compartment and along the lower fuselage. While a fracture was found near the oil dipstick port, laboratory testing indicated this was an impact-related failure caused by overload rather than a primary cause. The oil filter was found to be saturated with metallic particles, and debris recovered from the oil suction screen contained material from the connecting rods as well as steel from various fittings and fasteners.
Crucially, the oil suction screen plug was found to be loose and lacked the safety wire required by the manufacturer's maintenance manual. This plug was located on the oil sump, and oil was observed beneath it. Records indicated that eleven days prior to the accident, the engine had undergone maintenance to replace the turbocharger, which included the removal and reinstallation of this specific plug. The investigation concluded that the engine power loss resulted from oil starvation caused by the failure to properly secure the plug during that recent maintenance session.