A photo of the accident helicopter taken April 2013. Copyright Patrick Weis
The accident helicopter in April 2013. Copyright Patrick Weis
Robinson R44 Helicopter, ZK-HTB, collision with lake, Wanaka, 21 July 2018
Occurrence Date
The Commission has published an interim report as part of its ongoing inquiry into this fatal accident.

The wreckage under examination includes evidence in the main rotor mechanism symptomatic of the helicopter having experienced mast bumping at some point in the accident sequence.

Mast bumping is contact between an inner part of a main rotor mechanism and the main rotor drive shaft; it usually results in the helicopter breaking up in flight.

There is also evidence that a main rotor blade has struck and entered the cabin in flight. There are score marks on the blade that match screws on the canopy bow; there is scoured paint on the screws. The same rotor blade has marks matching damage to the flight instruments panel.

The report issued today is an interim report, so it includes no formal Findings. All evidence (including of any mast bumping) and the role it may have played in the accident sequence is subject to further investigation. The Commission is yet to complete its inquiry into this accident, and the information contained in the Commission’s Final Report may differ from that in this interim report.
Wanaka (-44.590000,169.128611) [may be approximate]