Accident Sequence
A helicopter instructor pilot and a dual student were conducting autorotation training exercises. The maneuvers involved autorotative approaches terminated with power recoveries at a 3-foot hover. On the sixth autorotative approach, the helicopter's engine failed, leading to a hard landing that substantially damaged the aircraft.
Post-Accident Findings
Following the accident, an operational test was performed on the engine. The test determined that the engine would not operate at idle RPM, indicating a malfunction that contributed to the loss of power during the approach.
Pilot Background
The certified flight instructor (CFI) had logged a total of 154 helicopter flight hours, of which 9 hours were in the accident helicopter make and model. Additionally, he had accumulated 20 hours of helicopter flight instruction experience.