Accident Overview
A helicopter sustained substantial damage during a hard landing while a certified flight instructor was demonstrating a practice 180-degree autorotation to landing. The incident occurred when the instructor permitted the helicopter to develop an excessive descent rate and low rotor rpm, conditions that led to a forceful contact with the asphalt surface.
Sequence of Events
According to the investigation, the instructor was performing an autorotation demonstration when the helicopter's descent rate became excessive and rotor rpm dropped below safe parameters. Although the instructor attempted corrective actions, the adjustments were not timely enough to prevent the helicopter from striking the ground. The impact was of sufficient force to cause substantial damage to the helicopter's airframe.
Investigation Findings
An examination of the helicopter after the accident revealed no mechanical anomalies. The helicopter's systems and components were found to be functioning normally, indicating that the hard landing was not caused by a mechanical failure. The investigation focused on the pilot's handling of the autorotation maneuver, specifically the failure to maintain proper descent rate and rotor rpm throughout the procedure.