Introduction
A helicopter crashed during a training exercise involving a 180-degree autorotation. The instructor pilot was having a student practice autorotations for an upcoming check ride.
Sequence of Events
During the final autorotation, the student rolled out of the turn. The helicopter decelerated to 60 knots, and the low rotor rpm warning horn sounded along with the caution light. At approximately 80 feet above ground level, the instructor called for a go-around, but the rotor rpm did not increase. The instructor then took control from the student, applying collective pitch and forward cyclic to achieve a touchdown with a level pitch attitude. The helicopter impacted the ground hard and began sliding sideways. The right skid dug into soft terrain, causing the helicopter to roll over three times before coming to rest on its left side.
Post-Accident Information
Neither the instructor nor the student reported any anomalies with the helicopter, which had accumulated 218 hours of flight time prior to the event. The flight school that employed the instructor had a policy requiring instructors to perform practice autorotations at a controlled airport equipped with emergency response equipment. If that was not possible, they were expected to recover from autorotations at an altitude of 500 feet above ground level.
No further details were provided regarding the specific aircraft model, registration, operator, location, or any injuries.