Incident Summary
A helicopter pilot reported that during a local area flight, he heard loud noises behind the cockpit, followed by a loss of torque to the rotor system. He immediately initiated an autorotation into a cornfield.
Landing Sequence
During the landing flare, the tailboom stinger contacted the ground. This pushed the tailboom upward into the path of the main rotor system. The helicopter then landed hard and rolled onto its right side.
Pilot Observations
The pilot noted that the accident could have been prevented if he had initiated his flare approximately two feet higher. However, he was unsure of his altitude above the ground at the time due to the corn crop and the dusk light conditions.
Post-Accident Inspection
A post-accident inspection of the helicopter revealed that one of the transmission drive belts had failed, and another belt had separated from its pulley assembly.