Flight and Communication
Radar data indicated the airplane was tracking north of its planned route. The aircraft made several heading changes and descended to 500 feet mean sea level. The pilot advised air traffic control that he was landing at Shreveport and was assigned a transponder code. No further transmissions were received from the pilot.
Impact and Damage
The airplane impacted transmission lines, poles, and trees approximately 19 miles northwest of the airport. The left engine and its accessories were extensively damaged by fire. The pilot, the sole occupant, was killed.
Engine Examination
Examination of the propellers showed that the right spinner dome had marks corresponding to 74°, while the normal operating range is 17° to 35°. The three blades of the left propeller exhibited only leading edge damage at their tips. Inspection of the right engine revealed carbon buildup in the exhaust and intake manifolds, pitted and scored exhaust valves, worn and pitted valve seats, worn spark plugs, compression below 60 on four cylinders, and a separated magneto block with pitting and fretting. The time since the last annual inspection performed by operator maintenance personnel was 78 hours.
Probable Cause
The official probable cause was determined to be a total loss of right engine power and a partial loss of left engine power for undetermined reasons.