What happened
The FAA’s narrative, in sentence case. The FAA writes it in capitals and removes private details.
Received report of accident in vicinity of matanuska Glacier involving a Robinson R-44II helicopter operated under part 91 rules. Interview with accident pilot in command conducted. He states that in cruise flight he heard an extremely loud bang with no precursor indications. He began slowing the aircraft for precautionary landing. At approxiamately 65 KIAS the aircraft began to yaw. He was not able to correct the yaw with input from the tail rotor pedals. He correctly diagnosed a loss of tail rotor authority. He maintained forward airspeed to control aircraft heading while descending. PIC conducted a successful autorotation to the ground on the matanuska Glacier. He described a short ground run with no further damage to the aircraft. The aircraft was recovered from the accident location via helicopter external load and repositioned to a maintenance location for evaluation and repair. Upon examination it was determined that the tail rotor dirve shaft (pn D196-1) had failed approxiamately 18 inches aft of the hanger bearing resulting in the loss of tail rotor authority. Aft section of the shaft fell onto the lower portion of the tail boom, damaging the tail boom, tail rotor push/pull tube and wiring for tail accessories.
As the FAA filed it
RECEIVED REPORT OF ACCIDENT IN VICINITY OF MATANUSKA GLACIER INVOLVING A ROBINSON R-44II HELICOPTER OPERATED UNDER PART 91 RULES. INTERVIEW WITH ACCIDENT PILOT IN COMMAND CONDUCTED. HE STATES THAT IN CRUISE FLIGHT HE HEARD AN EXTREMELY LOUD BANG WITH NO PRECURSOR INDICATIONS. HE BEGAN SLOWING THE AIRCRAFT FOR PRECAUTIONARY LANDING. AT APPROXIAMATELY 65 KIAS THE AIRCRAFT BEGAN TO YAW. HE WAS NOT ABLE TO CORRECT THE YAW WITH INPUT FROM THE TAIL ROTOR PEDALS. HE CORRECTLY DIAGNOSED A LOSS OF TAIL ROTOR AUTHORITY. HE MAINTAINED FORWARD AIRSPEED TO CONTROL AIRCRAFT HEADING WHILE DESCENDING. PIC CONDUCTED A SUCCESSFUL AUTOROTATION TO THE GROUND ON THE MATANUSKA GLACIER. HE DESCRIBED A SHORT GROUND RUN WITH NO FURTHER DAMAGE TO THE AIRCRAFT. THE AIRCRAFT WAS RECOVERED FROM THE ACCIDENT LOCATION VIA HELICOPTER EXTERNAL LOAD AND REPOSITIONED TO A MAINTENANCE LOCATION FOR EVALUATION AND REPAIR. UPON EXAMINATION IT WAS DETERMINED THAT THE TAIL ROTOR DIRVE SHAFT (PN D196-1) HAD FAILED APPROXIAMATELY 18 INCHES AFT OF THE HANGER BEARING RESULTING IN THE LOSS OF TAIL ROTOR AUTHORITY. AFT SECTION OF THE SHAFT FELL ONTO THE LOWER PORTION OF THE TAIL BOOM, DAMAGING THE TAIL BOOM, TAIL ROTOR PUSH/PULL TUBE AND WIRING FOR TAIL ACCESSORIES.
NTSB investigation
The NTSB’s investigation of this event, with its probable cause and findings. Matched to this report by N-number and date.