Accident Details
During a training flight aimed at practicing autorotations for a rotorcraft rating, a helicopter experienced a rollover upon touchdown. The student pilot, who was performing the maneuvers, stated the accident occurred on the third autorotation of the flight. According to the student, the airspeed dropped below 40 miles per hour, and the rotor rpm decayed. The student reported that the certified flight instructor (CFI) took control of the throttle, rolling it on and off approximately three times, but the helicopter was too slow and too low. The student described the impact with the ground as "hard."
Student's Account
The student noted that no mechanical failure or malfunction was observed with the helicopter, attributing the event solely to the loss of airspeed and rotor rpm. The student later stated, "I learned later that when practicing autorotations, I should not roll the throttle to idle, because there is a governor that keeps it at about 2,000 rpm when the collective is lowered." The student added that the CFI never provided instruction about not rolling the throttle to idle during autorotations.
CFI's Account
In contrast, the CFI reported that the engine quit during the simulated engine failure. The CFI stated that a full touchdown autorotation was executed into a soft field, and the left skid dug into the terrain, causing the helicopter to roll over.
Conclusion
The source provides two differing accounts of the event, with the student emphasizing pilot technique and the CFI focusing on an engine failure and terrain interaction.