Incident Details
While in flight, the pilot detected a severe vibration. He elected to perform an emergency autorotation to manage the situation. The helicopter touched down with forward speed in a flat, open bean field. During the landing, the skids became entangled in the bean plants, causing the helicopter to roll over. Shortly after the rollover, a cabin fire ignited.
Engine Examination
A post-crash teardown of the engine was conducted. Examination revealed that a #4 connecting rod bolt had failed. This failure resulted in an engine stoppage during the flight, which likely led to the vibration that prompted the autorotation.
No further details regarding the aircraft, occupants, or environmental conditions were provided in the investigation report.