Light chopper safety questioned

An investigation into a fatal helicopter crash in south Westland highlights serious safety problems with New Zealand's most commonly used light helicopters.

The Transport Accident Investigation Commission released its report this morning into the April 27, 2011 crash near Mt Aspiring that killed Wanaka Helicopters instructor Graham Stott, 31, and Marcus Hoogvliet, 21, a Queenstown electrician who was training to become a commercial pilot.

It called for a review of safety training and standards for Robinson helicopters as a result of its investigations.

Stott and Hoogvliet had been on a cross-country training flight from Wanaka to Haast in the two-seater Robinson R22 but on their return trip, the helicopter broke-up mid-flight and crashed near the head of the Arawhata River in Mt Aspiring National Park.

TAIC said the helicopter ''had been operating in a high-risk situation'' at the time because it was at a high altitude, close to its maximum permissible weight and entering an area of moderate to extreme turbulence.

Its main rotor blades had flapped beyond their normal rotation plane and struck the tail boom, severing the tail rotor from the machine.

One or more conditions had caused that, including severe or extreme turbulence buffeting the helicopter, the pilots making large abrupt movements of controls in response to turbulence or the main rotor speed dropping below its lowest limit.

''With the loss of the tail boom and rotor, the helicopter would have been instantly uncontrollable,'' the report said.

The pair had landed at Neils Beach that morning, about 35km south of Haast, and refuelled but on their return trip, they deviated from their planned route to cross the Matukituki Saddle, instead flying over nearby Waipara Saddle and into the Arawhata River valley.

''It is possible that the helicopter was forced across Waipara Saddle by a strong wind spilling over the saddle from the direction of Matukituki Saddle.''

TAIC found New Zealand's regulatory oversight provided insufficient guidance and mandatory requirements for instructors, pilots and operators of R22s that was needed to minimise the known risk of exceeding the helicopters' limitations.

Stott could have been unaware of the risks flying that type of helicopter at near maximum weight at high altitude in moderate to severe turbulence, the report said.

In 2012, there were 350 light helicopters operating in New Zealand and 90 per cent were R22 or R44 machines. However, 11 of the 26 fatal R22 crashes from 1985 to 2012 were caused by it breaking up mid-flight.

Another fatal R22 crash occurred after taking off from Wanaka Aerodrome in late 2012, which killed Wakatipu Aero Club's chief pilot and instructor, Julian Kramer, known as Julianne. A Civil Aviation Authority investigation revealed the helicopter's rotor blades severed the tail boom in mid-flight.

Today's report recommended the CAA reviewed Robinson safety awareness training in New Zealand and facilitated development and adoption of best practice across the sector.

''The format of the Robinson R22 helicopter flight manual and its terminology did not draw appropriate attention to safety-critical instructions and conditions that could result in serious injury or death.''

It also asked the CAA to review United States' standards for Robinson helicopters and to adopt improvements to boost safety in New Zealand.

TAIC noted the US tightened safety standards for Robinson helicopters in 1998 because of concerns over crashes but New Zealand's standards were weaker and failed to significantly reduce crash rates.

The CAA agreed to undertake both reviews and predicted they would take 12 to 15 months.

Stott's family spokesman and his brother-in-law, Corey O'Leary, said the family accepted the report's findings.

''It's been done by experts and we're quite happy with their findings. It's a bit of closure for us and we can finally move on.''

He said the only bright side of the ''terrible tragedy'' was that Stott died doing something he loved.

Hoogvliet's father, Henk Hoogvliet, said his family was pleased the report did not find any negligence by either pilot.

''They experienced an extreme wind event that overwhelmed the helicopter and from which they were unable to recover.

''Those who fly in and around the mountains appreciate how unpredictable conditions can sometimes be. It appears they just got caught out.''

He said his son had lived his life to the full and spent the happiest last 4 months of his life learning to fly.

The Press