The Royal Commission Report convincingly clears Captain Collins and First Officer Cassin of any suggestion that negligence on their part had in any way contributed to the disaster. That is unchallenged.
It continues on to explain why Mr Chippindale’s finding of pilot error was wrong:
The judge was able to displace Mr. Chippindale's attribution of the accident to pilot error, for two main reasons. The most important was that at the inquiry there was evidence from Captain Collins' widow and daughters, which had not been available to Mr. Chippindale at the time of his investigation and was previously unknown to the management of A.N.Z., that after the briefing of 9 November 1979 Captain Collins, who had made a note of the co-ordinates of the Western Waypoint that were on the flight plan used at that briefing, had, at his own home, plotted on an atlas and upon a larger topographical chart the track from the Cape Hallett waypoint to the Western Waypoint. There was evidence that he had taken this atlas and chart with him on the fatal flight and the inference was plain that in the course of piloting the aircraft he and First Officer Cassin had used the lines that he had plotted to show him where the aircraft was when he switched from nav track to heading select in order to make a descent to 2,000 feet while still to the north of Ross Island which he reported to ATC at McMurdo and to which he received ATC's consent. That on completing this descent he switched back to nav track is incapable of being reconciled with any other explanation than that he was relying upon the line he had himself plotted of the flight track on which he had been briefed. It was a combination of his own meticulous conscientiousness in taking the trouble to plot for himself on a topographical chart the flight track that had been referred to at his briefing, and the fact that he had no previous experience of "whiteout" and had been given no warning at any time that such a deceptive phenomenon even existed, that caused the disaster.
The other principal reason why the judge felt able to displace Mr. Chippindale's ascription of the cause of the accident to pilot error was that certain remarks forming part of the conversations recorded in the CVR of the crashed aircraft and attributed by Mr. Chippindale to the flight engineers had suggested to him that shortly before the crash they were expressing to the pilot and navigator uncertainty about the aircraft's position. The tape from the CVR which had been recovered from the site of the crash proved difficult to interpret. The judge, with the thoroughness that characterised him throughout his investigations, went to great pains to obtain the best possible expert assistance in the interpretation of the tape. The result was that he was able to conclude that the remarks attributed by Mr. Chippindale to the flight engineers could not have been made by them, and that there was nothing recorded in the CVR that was capable of throwing any doubt upon the confident belief of all members of the crew that the nav track was taking the aircraft on the flight path as it had been plotted by Captain Collins on his atlas and chart, and thus down the middle of McMurdo Sound well to the west of Mt. Erebus.
Then they confirm that Justice Mahon was correct in castigating the airline
The judge's report contains numerous examples and criticisms of A.N.Z.'s slipshod system of administration and absence of liaison both between sections and between individual members of sections in the branch of management that was concerned with flight operations. Grave deficiencies are exposed in the briefing for Antarctic flights; and the explanation advanced by witnesses for the airline as to how it came about that Captain Collins and First Officer Cassin were briefed on a flight path that took the aircraft over the ice-covered waters of McMurdo Sound well to the west of Mt. Erebus but were issued, for use in the aircraft's computer, as the nav track a flight path which went directly over Mt. Erebus itself, without the aircrew being told of the change, involved admissions of a whole succession of inexcusable blunders by individual members of the executive staff. None of this was challenged before their Lordships. No attempt was made on behalf of A.N.Z. to advance excuses for it.