Expert offers advice after fatal chopper crash
Helicopter pilots from across the country are being trained by a Swiss expert after a fatal helicopter crash in Wanaka four years ago.
Swiss pilot and former flight instructor Claude Vuichard is training 50 people, including pilots from the New Zealand Defence Force, about ‘‘vortex ring state’’ (VRS).
In the vortex ring state, helicopters lose the ability to maintain lift and begin to drop. As the helicopter is accelerated downwards in its own downwash, any increase in power worsens the situation, making the helicopter sink even faster.
According to the Civil Aviation Authority, the dangerous natural phenomenon contributed to 12 accidents in New Zealand in the past 18 years.
The training was prompted by a 2014 crash involving helicopter company The Helicopter Line Limited (THL).
Auckland construction company director Jerome Box, 52, was killed when the the Squirrel AS350B2 he was travelling in crashed on Mount Alta, Wanaka, in August 2014.
The helicopter rolled 700 metres down the slope before coming to a stop. Five of the seven occupants were ejected from the cabin, all suffering injuries. Box was crushed under the cabin and killed.
THL was convicted and fined $47,600 at a Queenstown District Court hearing before Judge JanMarie Doogue in March 2018.
THL chief executive Mark Quickfall said an internal investigation highlighted vortex ring state as a potential factor in the crash.
Quickfall said the onus was on ‘‘all of us’’ to investigate improvements to helicopter flying.
‘‘If this training can prevent future accidents, all the better,’’ Quickfall said.
THL director Grant Bissett said the Vuichard Recovery Technique had been used internationally for many years, saved lives and was now incorporated into military training.
It had been adopted by some helicopter manufacturers and used simple physics for a quick recovery with control.
‘‘The traditional VRS recovery technique involves significant height loss with the aircraft exiting VRS at a high rate of descent typically taking up to 200ft,’’ he said.
‘‘Whereas the Vuichard recovery exists VRS with minimal height loss of 20-50ft with the helicopter climbing under control – which is critical if you are close to terrain.’’
He believed it should become a fundamental part of basic helicopter training in New Zealand.
The technique had not been well understood and adopted in the aviation industry, he said.
‘‘There have been a number of accidents that have happened worldwide in recent years that simply didn’t need to . . . emergency medical service operations, night operations, military operations and a number of airshow accidents as well.’’
Lighter helicopters were more prone to getting into VRS, he said.
Vuichard said he estimated around 10 per cent of fatal accidents around the world were linked to the vortex ring state.
His technique involved flying sideways out of the vortex to catch the upwind part of the vortex rather than flying forwards which had been the traditional technique for about 70 years.
‘‘My technique is very efficient because in half a second you are out losing maybe 10m – no more – of altitude.
‘‘That helps you in every condition – in the mountains, in rescue missions. The important thing is we can avoid accidents and avoid fatalities.’’