What happened
During a cross-country flight, an aircraft experienced a sudden and complete loss of engine power while climbing through 12,000 feet MSL. The pilot reported that the engine's torque and compressor turbine RPM decreased abruptly, though no cockpit warnings or abnormal indications were observed prior to the event. Following the power loss, the pilot declared an emergency and attempted a 18able-degree turn to return to the departure airfield. Despite two separate attempts to restart the engine, the pilot was unable to restore power. Consequently, the pilot performed an off-airport forced landing. The impact resulted in substantial damage to the wings and the fuselage of the aircraft.
Findings
Post-accident investigations, including functional engine tests and examinations of the airframe and fuel systems, found no mechanical failures that would have prevented the engine from operating normally. However, investigators discovered that the fuel transfer pump switch was set to the manual position. While the engine was being supplied by the header tank, avionics data showed that the fuel level in that tank steadily declined throughout the flight. The automatic fuel transfer system failed to replenish the header tank because the system was not configured to do so. It is concluded that the improper configuration of the fuel transfer system led to fuel starvation, causing the engine to lose power.