What happened
During a flight involving a twin-engine cargo airplane, the pilot encountered a loss of engine oil, which necessitated shutting down the left engine and feathering the propeller. Following this mechanical issue, air traffic control provided vectors toward a VOR to assist with navigation. Because the aircraft was at an altitude and distance that placed it outside of radar coverage, the pilot was required to execute a complete instrument approach procedure.
While the aircraft initially maintained its assigned enroute altitude, radar data indicated a continuous descent throughout the procedure turn and the inbound leg of the approach. The final radar contact occurred approximately 300 feet below the prescribed inbound approach altitude while the aircraft was still positioned outside the final approach fix. The aircraft subsequently struck trees and terrain roughly 2.25 miles from the airport, which is located 5.5 miles from the VOR.
Findings
Post-accident investigation of the wreckage showed that the left engine's propeller had been feathered. Investigators also discovered that the number nine cylinder mounting studs on the engine case were either broken or crushed downward. Additionally, the landing gear was found in the extended position. The pilot, who was the only person on board, was killed in the impact.
Official findings concluded that the primary factor in the crash was the premature extension of the landing gear, which prevented the pilot from maintaining the minimum descent altitude required for the approach. Secondary contributing factors included the loss of oil and a loose cylinder.