What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Proto type flight test. Velocity and height test. Damaged on hard landing other same test similiar damage. (.4) while in the process of verifying a height/velocity performance data point, the pilot entered an autorotation at takeoff power and maximum gross weight. The onboard telemetry revealed that the pilot reduced the throttle to flight idle at the entry point but that the remaining momentum caused the aircraft to accelerate and climb. During the descent, the main rotor RPM decayed and an excessive vertical sink rate developed. The aircraft landed hard at the intended touchdown point. The aircraft was hover-taxied from the landing area and a normal shutdown was completed. The test pilot reported that the height/velocity data point was outside the aircraft's performance capabilities. (-23) see narrative #LAX98LA093.
As the FAA filed it
PROTO TYPE FLIGHT TEST. VELOCITY AND HEIGHT TEST. DAMAGED ON HARD LANDING OTHER SAME TEST SIMILIAR DAMAGE. (.4) WHILE IN THE PROCESS OF VERIFYING A HEIGHT/VELOCITY PERFORMANCE DATA POINT, THE PILOT ENTERED AN AUTOROTATION AT TAKEOFF POWER AND MAXIMUM GROSS WEIGHT. THE ONBOARD TELEMETRY REVEALED THAT THE PILOT REDUCED THE THROTTLE TO FLIGHT IDLE AT THE ENTRY POINT BUT THAT THE REMAINING MOMENTUM CAUSED THE AIRCRAFT TO ACCELERATE AND CLIMB. DURING THE DESCENT, THE MAIN ROTOR RPM DECAYED AND AN EXCESSIVE VERTICAL SINK RATE DEVELOPED. THE AIRCRAFT LANDED HARD AT THE INTENDED TOUCHDOWN POINT. THE AIRCRAFT WAS HOVER-TAXIED FROM THE LANDING AREA AND A NORMAL SHUTDOWN WAS COMPLETED. THE TEST PILOT REPORTED THAT THE HEIGHT/VELOCITY DATA POINT WAS OUTSIDE THE AIRCRAFT'S PERFORMANCE CAPABILITIES. (-23) SEE NARRATIVE #LAX98LA093.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.