Incident Sequence
The helicopter had been in flight for approximately 5 minutes when the main rotor rpm began to decrease. Subsequently, the "clutch light" illuminated and the "low rotor horn" sounded. The pilot initiated an autorotation to an open field but did not have enough altitude to clear some trees. The helicopter contacted the trees and impacted the ground "hard."
Post-Accident Examination
An examination by an aircraft mechanic and an FAA inspector revealed that the main rotor drive belts were separated from the drive wheels and were "frayed and ripped." No anomalies were noted with the rest of the drive system.
Maintenance Records
The helicopter was issued an airworthiness certificate on May 27, 1998. Its last annual inspection occurred on February 10, 2001, at an aircraft total time of 409.2 hours. There was no record of the drive belts being replaced during the life of the helicopter. According to the manufacturer, the drive belts are to be changed on condition, with no life limit; however, the belts usually get replaced during the helicopter's 2,200-hour overhaul. At the time of the accident, the helicopter had accumulated a total of 488 hours.
No further details were provided regarding the aircraft type, registration, operator, or occupants.