Aviation TAIC Report on fatal crash of helicopter whilst fighting 2017 Port Hills wildfires

26 June 2018
Image shows damage to monsoon bucket
Damage to monsoon bucket

The fatal crash of a firefighting helicopter during the February 2017 Port Hills wildfires is the subject of a Transport Accident Investigation Commission report published today.

Captain Tim Burfoot, the Chief Investigator of Accidents says the AS350 ‘Squirrel’ helicopter was on its way to refill its monsoon bucket when it encountered turbulence and wind shear, and a side window dislodged into the cabin and flew out of an open door.

“All the doors on the pilot’s side had been removed to make it easier for the pilot to see the monsoon bucket. The doors on the left side were closed. This door configuration was prohibited in the flight manual,” said Capt. Burfoot. 

The Commission found that it was about as likely as not that the door configuration contributed to the fluctuating pressure caused by the forward airspeed and turbulence, and that this likely forced the side window panel into the cabin interior and ejecting out through the open side door.

“The pilot reduced speed, causing the tail rotor to dip. The monsoon bucket swung up and backward, and the bucket line damaged the tail rotor assembly. This made the helicopter uncontrollable and it crashed. The pilot was fatally injured,” said Capt. Burfoot. 

Key lessons from this accident are that:
  • Vigilance during turbulence is vital
  • Pilots should understand the reasons for, and observe, the limitations of the aircraft they are flying
  • To help prevent future accidents, operators should record and investigate all operational incidents
  • Performance-impairing substances such as recreational drugs pose a serious risk to aviation safety. Their short- and long-term effects may be unpredictable and result in pilots being impaired when flying their aircraft. [The Commission found that it was very unlikely that the pilot’s recent use of cannabis impaired his performance at the time of the accident.]

The Final Report is available on the Transport Accident Investigation Commission website: https://taic.org.nz/inquiry/ao-2017-001