What happened
The accident occurred while a certified flight instructor (CFI) was conducting a training exercise for a prospective student. The specific maneuver being demonstrated was a departure autorotation, a procedure used to teach students how to maintain control during an engine failure immediately after takeoff.
During the execution of this maneuver, the helicopter developed a high rate of descent combined with low airspeed and critically low rotor revolutions per minute (RPM). Recognizing the deteriorating flight parameters, the CFI attempted to recover by applying power. However, the recovery was unsuccessful, and the aircraft impacted the ground with significant force.
The impact caused the helicopter's skids to collapse, resulting in a rollover. Following the incident, the pilot did not report any pre-existing mechanical failures or malfunctions. The only potential contributing environmental factor mentioned was the possibility of encountering shifting winds during the maneuver.
The investigation
Investigators examined the wreckage and interviewed the pilot regarding the sequence of events. No evidence of mechanical failure was found that would have prevented power recovery. The primary focus remained on the flight dynamics during the autorotation demonstration.
Findings
The accident was caused by the instructor's inability to recover from a high rate of descent with low airspeed and low rotor RPM during the departure autorotation demonstration. Fuel exhaustion was not cited, nor were mechanical failures. The hard landing and subsequent rollover were direct results of the failed power recovery attempt.