Pilot inexperience was the "key factor" in a helicopter crash at Kekerengu, near Kaikōura that killed two in December 2020.
The Transport Accident Investigation Commission (TAIC) released its report into the crash this morning.
Pilot Andrew Hamish Davidson, 60, and wife Lin Chen, 39, both of Ohoka in Canterbury, died in the accident.
Their two children and a school friend were seriously injured.
"The children survived largely because they were smaller and lighter than the adults," today's TAIC report said.
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"It was a good day for flying, with just a moderate north-easterly onshore breeze.
"The helicopter slowed as it turned towards the beach... this was a critical phase of the flight – transitioning from cruise to hover flight.
"The helicopter yawed suddenly, descended with uncontrolled increasing rate of yaw, and was destroyed when it crashed onto the beach," the report explained.
On board were the pilot and spouse, their two children and a child’s friend, the TAIC added.
And pilot error is given as the reason for the yaw.
The pilot increased main rotor power without also adjusting the tail rotor to keep the aircraft pointing in the right direction, the TAIC said.
"The pilot was focused more on the landing site and landing preparation, than on monitoring the performance of the helicopter, in particular the airspeed–groundspeed relationship," the report found.
"The pilot's inexperience was the key factor in their inability to regain control after being startled by the sudden yaw.
"There were no medical or mechanical issues identified that may have contributed to the loss of control."
The accident carries reminders for other pilots, the TAIC added.
"All pilots, including instructors and examiners, may benefit from the findings and lessons in this report.
"The number one priority for all pilots when flying is to fly the aircraft.
"The Commission has identified no new safety lessons for the sector, so the final report makes no new recommendations."
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