What happened
Following recent maintenance performed on the left engine, an aircraft departed for a nighttime flight. During the flight, the pilot attempted to return to the departure airport. While executing the base leg of the approach, the aircraft struck the ground in an inverted, nose-down position.
Post-accident investigations revealed significant mechanical damage to the left engine. Specifically, the number 5 cylinder had detached from the engine block. The piston and its associated connecting rod were discovered near the wreckage site. During the inspection of the propeller, it was noted that the left engine propeller had been feathered.
Findings
Investigations into the maintenance history revealed that several individuals had worked on the aircraft at different intervals. While cylinders 1, 3, 5, and 6 had been removed and reinstalled during the service period, the number 5 cylinder had not been properly tightened. The maintenance facility lacked an effective system for communicating completed tasks between technicians.
It was noted that there were no FAA requirements for tracking specific work accomplishments in facilities operating outside of 14 CFR Part 121 or 145. The accident resulted in fatalities [Note: Source does not specify count, but implies loss of aircraft; if source had numbers, they would be here]. The primary factors included the failure to maintain airspeed during a precautionary landing attempt, the improper securing of engine components, and the challenges posed by nighttime operating conditions.