More than five years after two men were killed in a helicopter crash on Homestead Peak in Mt Aspiring National Park, the coroner's inquest into the accident has not been completed.
Retiring Queenstown coroner Alan Macalister considered the matter again yesterday but once again adjourned the inquest after raising questions over why the safety risk in the Robinson R22 was identified by the helicopter's manufacturer and a leading aviation authority nearly 12 years before the accident but did not come to the attention of the Civil Aviation Authority.
The crash on March 5, 2006, killed Wanaka-based pilot Keith McKenzie (29), of Canada, and his passenger, American tourist Jonathan Stein (61). The men were taking a private sight-seeing flight in a Robinson 22 belonging to Wanaka Helicopters.
It crashed on Homestead Peak, near the Matukituki Valley, causing a large tussock fire.
A hearing into the crash was adjourned this January pending the receipt of the accident report.
A "long-awaited" first draft report was released to police in April, followed by a further report in May and a final report in July, Mr Macalister said in his adjournment decision, released yesterday.
The NZCAA report said it appeared control was lost before the pilot had time to make any deliberate manoeuvres and an in-flight break-up of the helicopter had occurred at least half a nautical mile before the impact point. Its investigation was unable to conclusively establish what had caused the left cabin door, which was struck by the main rotor blade, to detach.
Mr Macalister said the crash was the result of the passenger door detaching and damaging the rotor, causing irreversible loss of control. The most likely reason for the door detachment was the lack of a cotter pin securing the lower hinge.
The potential hazard arising from the absence of a cotter pin in the lower hinges of R22 doors had been identified in 1994 when the manufacturer introduced Revision H, which required all new helicopters and those overhauled after that date to be fitted with a lower door hinge that made provision for a cotter pin.
In late 1994, the UK CAA issued an airworthiness directive that required all UK registered R22 helicopters to be fitted with Revision H-compliant hinges by January 31, 1995, following an incident in a UK-registered R22.
In March 2008, as a result of what was learned from the Homestead Peak helicopter crash, the NZCAA issued an airworthiness directive requiring cotter door pins in both door hinges and regular inspection.
"A question that arises is why, when the manufacturer and one of the world's leading aviation authorities took such action, it effectively did not come to the attention of NZCAA and the industry in New Zealand for more than a decade?
"Has there been action taken to ensure that such risks do not presently exist in relation to other aircraft and to ensure that such important information will be ascertained and effectively communicated in future?"
Such questions would be the focus of continuing inquiries to determine whether any coronial recommendations or comments should be made, Mr Macalister said.
