Incident Summary
A pilot was practicing autorotations into an off-airport open field. The landing was hard, and the pilot sustained serious injuries as a result.
Pilot Report
According to the pilot, a shudder was felt during the autorotation. The pilot attempted to regain airspeed by applying forward cyclic control, but was unsuccessful in recovering airspeed.
Examination Findings
An examination of the helicopter was conducted following the incident. The examination revealed evidence that the main rotor rpm had been low during the maneuver. No discrepancies were found with the flight controls or the engine.
Summary of Findings
The investigation did not identify any mechanical issues with the flight controls or engine. The low main rotor rpm evidence indicates that the rotor speed was below optimal levels during the autorotation.