Incident Overview
A helicopter conducting training in 180-degree autorotations experienced a hard landing and subsequent rollover. The incident occurred while the student pilot was practicing the maneuver.
Sequence of Events
During the autorotation, the student pilot applied excessive collective input while turning. This caused the rotor rpm to decrease. In response, the student lowered the helicopter's nose to increase airspeed, resulting in a condition of low rotor rpm and high airspeed as the helicopter approached the landing area.
The student then rolled on the throttle, but the descent continued. The certified flight instructor (CFI) took control of the helicopter, but ground impact occurred before the CFI could arrest the descent. The helicopter landed hard and rolled over.
Probable Cause
The accident was caused by the student's excessive collective application during the autorotation turn, which led to low rotor rpm and a high airspeed condition, preventing a successful landing.