Controversial investigation - Erebus disaster

What went wrong?

With the death of so many people, it is not surprising that the investigations into the tragedy became a source of great debate and controversy.

New Zealand's chief inspector of air accidents, Ron Chippendale, released his report on the accident on 12 June 1980. Early in his investigation it became clear that there was no mechanical reason for the crash. The flight recorder tapes showed that there had been no emergency in the cockpit. Chippendale identified Captain Collins’s decision to drop below the approved level and continue at that height when the crew was not sure of the plane's position as the main cause of the accident.

The Mahon inquiry

Public demand saw the government announce a further one-man Royal Commission of Inquiry into the accident. This was conducted by Justice Peter Mahon.

Mahon's report, released on 27 April 1981, disagreed with Chippendale’s findings and cleared the crew of blame for the disaster. Mahon argued that the single dominant cause of the crash was the changing of the aircraft's navigation computer co-ordinates. The white-out conditions, which he described as ‘a malevolent trick of the polar light’, meant that the crew was unable to see the mountain in front of them.

He also suggested that they may have experienced the rare meteorological phenomenon called ‘sector white-out’, which creates the visual illusion of a flat horizon far in the distance. Mahon noted that the flight crew had considerable experience with the extreme accuracy of the aircraft's inertial navigation system. He also established that the radio communications centre at McMurdo Station had authorised Collins to descend to 450 metres, below the minimum safe level.

‘An orchestrated litany of lies’

Mahon’s most damning criticism was directed at the management of Air New Zealand. He claimed that airline executives and management pilots had engaged in a conspiracy to whitewash the enquiry, accusing them of covering up evidence and misleading investigators through ‘an orchestrated litany of lies’.

Air New Zealand and the Civil Aviation Division were ordered to pay the costs of the inquiry, and the airline had to pay an extra fee of $150,000. The chief executive of Air New Zealand, Morrie Davis, resigned a week after the report was released to the public.

Air New Zealand appealed against Mahon's findings to the Court of Appeal, which set aside the costs order against the airline. Mahon turned to the Privy Council in London to support his conclusions. His findings as to the cause of the accident were not challenged either in the Court of Appeal or Privy Council, but the latter found that Mahon had acted in excess of his jurisdiction. He was also deemed to have breached natural justice by accusing Air New Zealand of conspiring to cover up the errors of its ground staff. The Privy Council dismissed Mahon's appeal and upheld the decision of the Court of Appeal in October 1983.

Police Commissioner Bob Walton, in consultation with the Solicitor-General, advised the government against pursuing any criminal prosecutions. He argued that, with the aircrew dead, it was unlikely that any conviction could be obtained against other parties.

Ultimately, whoever or whatever was responsible for the Erebus tragedy was of little comfort to the friends and family of the 257 people who perished in Antarctica. Almost all of the wreckage still lies on the slopes of Mt Erebus, under a layer of snow and ice. During warm periods when snow recedes, it is still visible from the air. The registration of the aircraft in the accident, ZK-NZP, has not been reissued.