What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
The accident happened during the takeoff phase of flight. The pilot stated that he completed his preflight inspection and engine runup and was about to depart for a personal flight with his son as a passenger. The pilot stated that he recognized that "ground resonance" was happening, and he tried to reduce the throttle to help eliminate the condition. The helicopter main rotor mast broke off just above the gear box. The rotor fell aft severing the tail boom and tail rotor. The helicopter remained upright on the skids. The pilot was certified and current to operate the helicopter with passengers.
As the FAA filed it
THE ACCIDENT HAPPENED DURING THE TAKEOFF PHASE OF FLIGHT. THE PILOT STATED THAT HE COMPLETED HIS PREFLIGHT INSPECTION AND ENGINE RUNUP AND WAS ABOUT TO DEPART FOR A PERSONAL FLIGHT WITH HIS SON AS A PASSENGER.THE PILOT STATED THAT HE RECOGNIZED THAT "GROUND RESONANCE" WAS HAPPENING, AND HE TRIED TO REDUCE THE THROTTLE TO HELP ELIMINATE THE CONDITION. THE HELICOPTER MAIN ROTOR MAST BROKE OFF JUST ABOVE THE GEAR BOX. THE ROTOR FELL AFT SEVERING THE TAIL BOOM AND TAIL ROTOR. THE HELICOPTER REMAINED UPRIGHT ON THE SKIDS. THE PILOT WAS CERTIFIED AND CURRENT TO OPERATE THE HELICOPTER WITH PASSENGERS.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.