Accident Details
A certificated flight instructor and a private pilot who was also a commercial student were conducting a dual instructional flight in a helicopter. The purpose of the flight was to practice pinnacle approaches, landings, and takeoffs. The landing area was situated at approximately 3,600 feet above mean sea level, near the top of a steep mountain ridge.
During the training session, two approaches to the pinnacle landing zone were performed: one resulted in a go-around, and the other ended with a landing. The instructor pilot noted that the student tended to allow the main rotor RPM to droop when adding power to terminate the approach.
Approach and Recovery Attempt
On the third approach, the main rotor RPM again began to decrease. The instructor pilot took control of the helicopter and attempted to increase the throttle setting and decrease collective pitch to recover from the low rotor RPM condition. Despite these efforts, the main rotor RPM continued to decrease. The instructor then attempted to land at the edge of the ridge. The helicopter slid backward over the edge of the mountain and began to break apart, tumbling approximately 600 feet down the mountainside. A post-crash fire erupted during the break-up sequence.
Occupant Injuries and Wreckage Examination
The instructor was ejected from the helicopter. The student remained in the wreckage and received fatal injuries. A post-accident examination of the wreckage disclosed no evidence of any preexisting mechanical failures or malfunctions.