Accident Sequence
The private pilot and passenger had just departed in a single-engine experimental helicopter when a loud pop was heard, followed by a loss of engine power. The pilot initiated an autorotation from an altitude of 75 feet and flared at approximately 40 feet above the ground to avoid trees. The helicopter made a hard landing in a grass field, causing the skids to spread upon impact.
Post-Impact Fire and Evacuation
After the helicopter came to rest, the two occupants were able to deplane. The engine exhaust then ignited the surrounding grass, and the resulting fire destroyed the helicopter.
Pilot Report and Examination
The pilot reported that the main drive belt, which had been recently replaced, had failed. An FAA inspector examined the wreckage; however, the drive belt could not be located and was assumed to have been destroyed in the post-impact fire.