A former Air New Zealand pilot who helped transcribe the on-flight recordings found among the plane wreckage on Mount Erebus 40 years ago has welcomed plans for a memorial of the disaster.
Levin man Arthur Cooper, now aged 83, was a former captain with Air New Zealand and one of a team of three men sent from New Zealand to the United States in the days following the disaster to transcribe recordings of the final moments of the flight.
Right up until the second the recording stopped.
"I certainly didn't volunteer for it, but someone had to do it," he said.
Air New Zealand Flight TE901 crashed into Mt Erebus in Antarctica on November 28, 1979, killing all 257 people onboard.
Cooper said a fitting memorial for those who died was long overdue, as was the formal apology delivered by Prime Minister Jacinda Ardern at the memorial service in Auckland to mark the 40th anniversary of the tragedy.
He said it would also go some way to honouring the memory of the flight crew, who were initially and wrongly blamed for the disaster.
Cooper was in a unique position to comment. In addition to being a pilot himself and transcribing the tapes, he also sat in on at the official Commission of Inquiry into the cause of the disaster, every day for three months.
He had long held the view that the captain and crew were in no way culpable for what was a series of systemic blunders that led to the crash.
Cooper said the Commission of Inquiry was essential to determine exactly what had happened, irrespective of what it uncovered. The truth was so important in the aftermath of such an aviation tragedy.
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"It was shattering news when word got out it had crashed," he said.
Cooper said he became astounded at some of the evidence presented as the inquiry wore on.
"I learnt so much about human nature through the inquiry, just watching and observing," he said.
"I think when people are under stress the brain can make you believe something else. Eventually what happens over time and with pressure is you come to the conclusion that you actually did a perfect job, and you genuinely believe it," he said.
"You convince yourself it happened differently...it's the job of the brain to protect you."
Cooper took his concerns straight to the head of Air New Zealand, Morrie Davis, who eventually appointed a member of flight staff to sit in on the inquiry.
"I wanted to tell him that things don't look good and there should be someone there to fulfill the role of attending every day and reporting back to them," he said.
"Initially he didn't want a bar of it."
Cooper said a turning point was when pilot Les Simpson spoke to a brief he had totally prepared himself.
"What he said was totally believable," he said.
Cooper said he had so much respect for the late Justice Peter Mahon QC, who was appointed as sole Commissioner to the inquiry and maintained his integrity under immense pressure.
He said when Mahon adjourned there was an anxious wait as to what his findings would be.
"I certainly had absolutely no idea or indication of what line his report might take.
"But he got it exactly right," he said.
"It was a measure of the man ... He could have cut them all up for mince meat, but he wasn't there to do that. He didn't want to ruin their futures or personally criticise them."
In his summary, Mahon famously said he was forced to listen to an "orchestrated litany of lies". It was then that the focus of the inquiry shifted to the man, not the ball, he said.
"He was so astute and in the end they used it against him," he said.
"It became dinner time for the legal people. It was their show now, trying to put everything to a point of law. Ironically though, from those who criticised so severely, I have yet to hear of another way that he could have got his point across of having to listen to a heap of bullshit without destroying the reputations of fine people generally held in high regard in the community."
Cooper had always believed that in no way was Captain Jim Collins and crew at fault, and the tragedy was a result of a flight plan error that wasn't picked up visually at the time due to a phenomenon now known as "whiteout".
His long-held view was shared by his peers at the time.
"The common thing, which they said again and again, was if it caught Jim it would have caught me," he said.
"If I was in Jim's position I would have made the same mistake. So many others said If it got Jim, it would have got me too...I knew him. I never flew with him, but he had a very high reputation and was very highly respected," he said.
Cooper said the flight crew could not see Mount Erebus directly in front of them due to a condition known as whiteout, unique to polar environments, where cloud and snow reflect light to provide the appearance of a false horizon far in the distance.
They had trusted their in-flight navigation systems and the co-ordinates they had been given, which were later found to have set them on the collision course with the mountain.
Cooper said all the basic procedures were followed after a pre-flight briefing. He said Collins was given a flight plan two weeks before take-off and would have studied them meticulously.
However the McMurdo co-ordinates were changed by the Navigation Section the day prior to Collins' flight and activated into the Nav computer at 2am on the day of the flight.
"That change should have been Notammed."
"Notam is a mnemonic for "notices to airmen" and is, and I emphasise this, a mandatory requirement to do so." he said.
"Notams are a file attached to every flight's documentation at the preflight briefing. Quite simply, if those changed co-ordinates had been notammed, which was mandatory, we wouldn't all be discussing the rights and wrongs of that disaster 40 years later."
A flight plan was a series of pre-determined waypoints, roughly around 300 miles apart. The final co-ordinates were changed by just two degrees on the last mark, or waypoint, so by the time it neared Mt Erebus, the route to the next waypoint had sent the plane 27 miles off course.
"The sad thing was they saw what they could have been expected to see if they were where they were supposed to have been ... sheer coincidence."
There were five men on the flight deck. All five believed they were looking at the entrance to McMurdo Sound, which they were briefed on. In reality, they were looking towards Mt Erebus.
Transcribing the voice recordings was a tough job and one that had to be done with the utmost accuracy so that a clear and accurate record could be used in the forthcoming inquiry and investigation into the cause of the crash.
"Listening to the deceased guys talking was stressful. After a while though, it was like we were all together, sort of socialising. It was like they were there," he said.
"You found yourself talking with them."
Cooper said they were at pains to ensure that what was produced was accurate. Every word had to be unanimously agreed to among the team and, having known the men onboard, exactly who said it.
There were some words that didn't sound exactly correct, but then became clear once put in context.
"It was a learning curve," he said.
They had flown the CVR voice recordings and the "black box" to its manufacturers in San Francisco, then on to the NTSB (National Transport Safety Board) audio laboratory in Washington DC where they spent countless hours deciphering what was recorded.
The black box would reproduce every detail of the aircraft's course, speed, altitude and manipulation of controls throughout the whole of its journey, while CVR would contain a recording of all that had been said in the last 30 minutes of the flight.
Both pieces of equipment were undamaged when they were recovered from Mt Erebus.
The transcriptions were used in the Commission of Enquiry to determine why the Air New Zealand DC10 crashed into Mt Erebus on November 28, 1979, claiming the lives of all 257 people onboard.
Cooper still has the transcripts from Flight TE901 bound in a folder at home.
He had always been critical of a subsequent transcription of the recordings commissioned by Chief Inspector of Accidents Ron Chippindale, carried out in the UK.
He said that transcription, used in what is known as the Chippindale Report, had not been conducted under the same level of scrutiny as those used in the inquiry, and differed from the one he had painstakingly prepared.
There were words in that transcription that simply weren't said, he said.