Accident Details
A pilot with 2,910 hours of flight time reported that while maneuvering to return to a field where he was performing aerial application, the engine lost power. The pilot saw three sets of power lines directly in front of his position and pitched up to avoid hitting them. As the airplane crossed over the third set of power lines, it stalled and impacted terrain in a left wing and nose low attitude.
Engine Examination
Examination of the engine revealed that the crankshaft was fractured at the cheek for the number two cylinder. A metallurgical examination performed on the crankshaft showed that the fracture initiated from at least two distinct origins in the fillet between the number three cheek and number two main journal, with beach marks throughout. The edge of the fractured surface was smeared.
Cause Determination
Despite the examination findings, the reason for the failure of the crankshaft was undetermined.