Air chief confident of finding cause

Iroquois air crew wait for cloud to clear over the crash site near Pukerua Bay. Photo / Mark Mitchell

The investigation into yesterday's crash will focus on the aircraft, the crew's pre-flight briefing, planning and their competency and training.

Investigators will today sift through the wreckage of the RNZAF Iroquois helicopter, one of three that left Ohakea Air Base for Anzac Day services in Wellington but crashed in hills 40km northwest of the city at about 6am.

Air Vice-Marshal Graham Lintott told a conference at Ohakea Air Base yesterday that it was too early to know the cause but said something went "very, very wrong".

The investigation will also look at who was in charge of the controls and whether the pilots, who had night vision goggles on board, were using them at the time of the crash.

The Iroquois does not carry a black box but Air Vice-Marshal Lintott, who thought there could be evidence from the wreck's instrumentation, was confident the cause of the crash would be determined.

"And, of course, we had two crews who can tell us what happened up to the point that they remember being in contact," he said.

"The accident investigators who are very adept at putting together this jigsaw puzzle I'm sure, in time, will be able to tell us what happened."

A court of inquiry was being convened by the Air Force.

Air Vice-Marshal Lintott said the airmen would not have been authorised to undertake this flight "if we didn't have the full confidence in their capabilities, their professionalism [and] health to do that flight."

Helipro chief executive Rick Lucas, whose Pukerua Bay farm is about 1km from the crash site, told the Herald he had offered his personal helicopter to assist rescue efforts.

He said poor weather conditions should not have affected pilot or helicopter performance.

"They [the pilots] would have been operating under visual flight rules so they would have had to see land or water below them so there was nothing in the conditions that would have impeded them," said Mr Lucas.

Alan Beck, of Beck Helicopters, said the Iroquois was one of the world's most reliable helicopters.

Mr Beck, who has flown Bell helicopters for 38 years and bought the first restricted category ex-military Iroquois to New Zealand in 1990, said the US military were shutting down their Apache and the Blackhawk builds to go back to the Iroquois.

"Around the world the people that run these things commercially and in the military know they are one of the most robust helicopters ever made."

Aviation commentator Peter Clark said while the iroquois fleet were overdue for replacement, the RNZAF had maintained them to an incredibly high standard. "You could probably say these machines are better now than the day we bought them."