What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Airman was conducting air tour operations at approximately 400 feet AGL at 75 knots on approach to landing when the aircraft developed abnormal medium-frequency vibrations and the alternator warning light illuminated. The airman immediately entered an autorotative descent and maneuvered toward an open field. Airman failed to maintain rotor RPM throughout the decent resulting in the low rotor RPM warning activating during the decelation just before touchdown. The aircraft landed hard, and the main rotor blades contacted the tail cone, separating it from the aircraft.
As the FAA filed it
AIRMAN WAS CONDUCTING AIR TOUR OPERATIONS AT APPROXIMATELY 400 FEET AGL AT 75 KNOTS ON APPROACH TO LANDING WHEN THE AIRCRAFT DEVELOPED ABNORMAL MEDIUM-FREQUENCY VIBRATIONS AND THE ALTERNATOR WARNING LIGHT ILLUMINATED. THE AIRMAN IMMEDIATELY ENTERED AN AUTOROTATIVE DESCENT AND MANEUVERED TOWARD AN OPEN FIELD. AIRMAN FAILED TO MAINTAIN ROTOR RPM THROUGHOUT THE DECENT RESULTING IN THE LOW ROTOR RPM WARNING ACTIVATING DURING THE DECELATION JUST BEFORE TOUCHDOWN. THE AIRCRAFT LANDED HARD, AND THE MAIN ROTOR BLADES CONTACTED THE TAIL CONE, SEPARATING IT FROM THE AIRCRAFT.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.