Fig.13 from the report
Robinson R22, ZK-HEQ, loss of control in flight, Karamea, West Coast, 2 January 2022
Status
Closed
Occurrence Date
Report Publication Date
Jurisdiction
NZ
What happened
On 2 January 2022 a Robinson Helicopter Company R22 helicopter, registration ZK HEQ, was being used to transfer two passengers from Karamea to a remote landing spot in Kahurangi National Park, from where the passengers were to go hunting.
Shortly after dropping off the second passenger, and on the return flight to Karamea, the pilot experienced a vibration and heard an associated noise. The pilot considered their options and elected to proceed with the flight to Karamea.
During the landing sequence at Karamea, the helicopter broke up in the air and struck the ground. The helicopter was destroyed and the pilot, who was the sole occupant, was seriously injured.
Why it happened
The Transport Accident Investigation Commission (the Commission) found that the helicopter very likely experienced a rotor overspeed. This is when the drivetrain exceeds the manufacturer’s revolutions per minute speed limit.
The rotor overspeed very likely caused the tail rotor drive shaft to deform.
When landing, the increased power and addition of collective very likely caused the tail rotor drive shaft to deform to the extent that it contacted the tailcone’s internal structure and tail rotor control tube. This resulted in a complete loss of drive and control to the tail rotor. The pilot then lost directional control of the helicopter.
The Commission was unable to conclusively determine when the rotor overspeed occurred. However, based on the evidence it likely occurred during take-off on the return flight to Karamea. The Commission could not rule out that another rotor overspeed could have occurred as the helicopter attempted to land at Karamea.
The cause of the rotor overspeed was very likely a result of the helicopter being flown inadvertently outside the Robinson R22 approved rotor speed limitations.
What we can learn
Helicopters need to be operated in accordance with the operational limitations of the Pilot’s Operating Handbook.
Helicopter pilots need to respond quickly to the symptoms of problems and comply with the manufacturers’ instructions pertinent to the incidents and the aircraft types.
Who may benefit
All pilots may benefit from the findings and lessons in this report.
On 2 January 2022 a Robinson Helicopter Company R22 helicopter, registration ZK HEQ, was being used to transfer two passengers from Karamea to a remote landing spot in Kahurangi National Park, from where the passengers were to go hunting.
Shortly after dropping off the second passenger, and on the return flight to Karamea, the pilot experienced a vibration and heard an associated noise. The pilot considered their options and elected to proceed with the flight to Karamea.
During the landing sequence at Karamea, the helicopter broke up in the air and struck the ground. The helicopter was destroyed and the pilot, who was the sole occupant, was seriously injured.
Why it happened
The Transport Accident Investigation Commission (the Commission) found that the helicopter very likely experienced a rotor overspeed. This is when the drivetrain exceeds the manufacturer’s revolutions per minute speed limit.
The rotor overspeed very likely caused the tail rotor drive shaft to deform.
When landing, the increased power and addition of collective very likely caused the tail rotor drive shaft to deform to the extent that it contacted the tailcone’s internal structure and tail rotor control tube. This resulted in a complete loss of drive and control to the tail rotor. The pilot then lost directional control of the helicopter.
The Commission was unable to conclusively determine when the rotor overspeed occurred. However, based on the evidence it likely occurred during take-off on the return flight to Karamea. The Commission could not rule out that another rotor overspeed could have occurred as the helicopter attempted to land at Karamea.
The cause of the rotor overspeed was very likely a result of the helicopter being flown inadvertently outside the Robinson R22 approved rotor speed limitations.
What we can learn
Helicopters need to be operated in accordance with the operational limitations of the Pilot’s Operating Handbook.
Helicopter pilots need to respond quickly to the symptoms of problems and comply with the manufacturers’ instructions pertinent to the incidents and the aircraft types.
Who may benefit
All pilots may benefit from the findings and lessons in this report.
Location
Karamea, NZ (-41.250625,172.119842) [may be approximate]