Event Summary
Approximately three minutes after departure, the pilot reported that the engine began to knock loudly and experienced a loss of power. In response, the pilot initiated a forced landing. During the landing attempt, the airplane's wing struck a pole, and a post-impact fire ensued, destroying the aircraft.
Engine Examination
Following the accident, an examination of the engine was conducted. The inspection revealed a fractured crankshaft. The crankshaft had accumulated about 1,196 hours of operation since a remanufactured unit had been installed.
Metallurgical Analysis
The fractured surfaces were examined by a National Transportation Safety Board metallurgist. The metallurgist determined that the failure was the result of fatigue that initiated at multiple sites along the surface of the aft radius of the number 2 main bearing journal.