Accident Details
While maintaining a stabilized hover out of ground effect at approximately 300 feet above ground level (AGL), the helicopter suddenly entered an uncontrollable right turn. The pilot reported that applying full left pedal had no effect in stopping the rotation. At the onset of the spin, the occupants felt a high-frequency vibration.
Pilot Actions
The pilot stated that he reduced rotor RPM by rolling off the throttle and lowered the collective. Despite these actions, the helicopter descended into trees while still in a right spin.
Post-Accident Statements
The pilot indicated that he did not believe there was any mechanical problem with the helicopter. The copilot, however, expressed the opinion that they had experienced a loss of tail rotor authority.
Investigation Findings
An investigation revealed no mechanical problems with the helicopter. Review of the height-velocity chart for the Bell 206L-1 indicated that a successful autorotation from a hover at 300 feet AGL is not probable. The elevation of the crash site was approximately 6800 feet MSL.