Ron Chippindale, the chief inspector of air accidents, at the Royal Commission of Inquiry into the Erebus disaster.
The accident investigation and Chippindale’s reports
Once the site investigation in Antarctica was completed, Ron Chippindale and his investigators returned to New Zealand to continue their enquiries. This included checking the personnel records of the crew and studying the weather conditions at the time of the crash and other possible contributing factors. Chippindale visited the United States and the United Kingdom in late December and early January. He vinterviewed, among others, the manufacturers of parts of the aircraft and the scientists who had analysed the information on the digital flight data recorder (DFDR) and the cockpit voice recorder (CVR).
On 4 March 1980 the interim accident report was sent to parties which Chippindale considered might bear 'some degree of responsibility for the accident': the legal representatives of the estates of the pilot and co-pilot of Flight TE901, Air New Zealand and the Civil Aviation Division (CAD) of the Ministry of Transport. They were given 90 days to comment on the report before it was finalised.
At the time Chippindale refused to reveal who had been sent the interim report, saying that to do so would indicate the report's findings. But it soon became clear who had not received it - including the aircraft's manufacturers, McDonnell Douglas - and it was reported that an aircraft fault had been eliminated as a cause. The opposition Labour Party, a consortium representing the estates of deceased passengers, and the New Zealand Airline Pilots Association (NZALPA) were among those demanding to see the report. NZALPA eventually obtained a copy of the report from the legal representatives of the pilot and co-pilot, and learnt that it attributed the accident to pilot error.
Calls for a public inquiry, which had begun shortly after the accident, continued amid the controversy about who had received Chippindale's interim report. On 6 March the Attorney-General, Jim McLay, requested a copy of the report to help him determine if a public inquiry should be held. Two days later he announced that a Royal Commission of Inquiry would be asked to investigate the 'place, time, causes, and circumstances of the accident, together with any other matters that might involve the public or civil aviation safety'.
McLay denied that the contents of the report had influenced his decision, arguing that there was no question that there should be an inquiry into an 'accident of such magnitude'. On 21 April Justice Peter Mahon was appointed to conduct the inquiry.
A number of parties, including Mahon, the consortium, NZALPA and Air New Zealand, protested against the planned release of Chippindale's final report before these hearings. They argued that all of the events related to the accident would be laid out at the Inquiry, at which the findings of the report could be cross-examined. But the government went ahead with the public release of the report at midnight on 19 June.
In the days prior to the release Chippindale advised the media that he had had difficulty finding 'the ultimate cause'. His report set out the 'probable cause - the last thing that made the accident inevitable', but other factors had led up to the accident.
These other factors, outlined in the conclusions section of Chippindale's report, included 'omissions and inaccuracies' in the route qualification briefing - in particular, that it may have given a misleading impression of the route - and the fact that the route was changed after the briefing. Criticism was directed at Air New Zealand and CAD for these and other failures. But the ‘probable cause’ to which Chippindale referred was:
The decision of the captain to continue a flight at low level toward an area of poor surface and horizon definition when the crew was not certain of their position and the subsequently inability to detect the rising terrain which intercepted the aircraft's flight path.
Chippindale concluded that the flight would have proceeded safely had the pilot not descended below the minimum safe altitudes specified by CAD and Air New Zealand.
While the criticisms levelled at Air New Zealand and CAD were widely reported by the media, the focus was on Chippindale's finding that the 'probable cause' of the tragedy was pilot error.
Part of: Finding the cause
Next page: The Royal Commission of Inquiry Inquiry and Mahon's report
Further information
- History of air accident investigation (NZALPA's Erebus website)
- Chippindale report (NZALPA's Erebus website)
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