Accident Sequence
On the day of the accident, the airplane was loaded with cargo that was not weighed. Weight and balance calculations were not performed before the flight. The aircraft was approximately 321 pounds over its maximum gross weight. While taxiing, a witness observed black smoke trailing from the left engine, which had been worked on the night before the accident. Two cylinders on that engine had been serviced, and a fuel injector nozzle had been cleaned.
After takeoff, the climb was described as 'low and slow.' During the climb, the airplane rolled to the left, pitched nose down, and impacted the ground. It came to rest adjacent to a house. The pilot, who was the sole occupant on board, was killed.
Examination
Post-accident examination of each engine revealed no evidence of internal mechanical failure or malfunction. Heat damage prevented testing of the magnetos, turbocharger components, and fuel servos on both engines. Examination of each propeller showed no evidence of preimpact failure or malfunction. The fuel nozzles from the left engine were found to be blocked in various places due to contaminants.
Following the accident, the FAA conducted a focused inspection of the operator. The inspection revealed that cargo was not being weighed, the chief pilot of the company held the position in name only, and the company was not maintaining load manifests.
Probable Cause
The official probable cause of the accident was an in-flight loss of control due to the pilot-in-command's failure to maintain VMC shortly after takeoff. Contributing factors included a partial loss of engine power from the left engine due to partial blockage of several fuel injector nozzles, weight and balance being exceeded by the pilot-in-command, and inadequate surveillance by the company and by the FAA.