Chopper firm fined $600k over nut

Judge decides the cause of a Fiordland helicopter crash in 2013 was a loose ‘B-nut’

Ahelicopter fuel-system “B-nut” loose by a quarter of a turn has cost Wanaka company Heli Support New Zealand almost $600,000. The company was sued by helicopter operators D.J. and N.A. Shanks at the High Court in Invercargill, claiming the cost of repairs to their

chopper from a 2013 Fiordland crash.

Judge Susan Thomas has ordered the firm to pay Shanks US$390,643.91 ($597,000) plus interest and costs.

After a five-day hearing in Invercargill in May, Judge Thomas said she was satisfied the nut was not properly torqued so Heli Support had “breached its duty of care”.

Judge Thomas said that on May 27, 2013, Sean Mullally and Sarah de Reeper were flying a Hughes MD369 (now MD500) series helicopter, from the Heli Support workshop to Mirror Lakes in the Eglinton Valley.

“They flew through a light snow shower lasting about a minute.”

During the descent, when the helicopter was about 46m up, the engine flamed out and stopped.

“Mr Mullally managed to control the helicopter so that it touched down . . . [but] although [he] was able to bring the helicopter to a stop, the main rotor blades severed the tail boom.”

Judge Thomas said the question was why the engine stopped.

Evidence centred on the “B-nut” in the fuel system which was onequarter turn loose when inspected after the accident.

A test by investigators showed that with the B-nut loosened one quarter turn “there was an immediate substantial leakage of fuel”.

Heli Support did not accept the B-nut was loose when the helicopter left Wanaka or that it caused the engine failure, arguing it was “more likely than not that the accident was caused by snow ingestion”.

Aaron Shaw, then chief engineer at Oceania Aviation, said that on inspection “one of the first things he noticed was that the fuel line to the filter head was loose”. Aviation and engineering loss adjuster Peter Webb gave evidence of more than one blue “torque stripe” — intended to show any misalignment — on the B-nut, “one-quarter turn, loose”.

Jason Buick, a Heli Support licensed aircraft maintenance engineer with 30 years’ experience, who worked on the helicopter prior to the crash, “was certain the B-nut was not loose when the helicopter was returned to service on 27 May, 2013”.

Judge Thomas did not find the theory of snow being the cause a “reasonable possibility”.