grasp of the flying involved in jet-airline operation, as he (and the New Zealand CAA in general) was typically involved in investigating simple light aircraft crashes. Chippindale's investigation techniques were revealed as lacking in rigour, which allowed errors and avoidable gaps in knowledge to appear in reports. Consequently, Chippindale entirely missed the importance of the flight-plan change and the rare meteorological conditions of Antarctica. Had the pilots been informed of the flight plan change, the crash would have been avoided. Court proceedings Judicial review On 20 May 1981, Air New Zealand applied to the High Court of New Zealand for judicial review of Mahon's order that it pay more than half the costs of the Mahon inquiry, and for judicial review of some of the findings of fact Mahon had made in his report. The application was referred to the Court of Appeal, which unanimously set aside the costs order. The Court of Appeal, by majority, though, declined to go any further, and in particular, declined to set aside Mahon's finding that members of the management of Air New Zealand had conspired to commit perjury before the inquiry to cover up the errors of the ground staff. Privy Council appeal Mahon then appealed to the Privy Council in London against the Court of Appeal's decision. His findings as to the cause of the accident, namely reprogramming of the aircraft's flight plan by the ground crew, who then failed to inform the flight crew, had not been challenged before the Court of Appeal, so were not challenged before the Privy Council. His conclusion that the crash was the result of the aircrew being misdirected as to their flight path, not due to pilot error, therefore remained. Regarding the issue of Air New Zealand stating a minimum altitude of 6,000 feet for pilots in the vicinity of McMurdo Base, the Privy Council stated, However, the Law Lords of the Privy Council under the chair of Lord Diplock effectively agreed with some of the views of the minority in the Court of Appeal in concluding that Mahon had acted in breach of natural justice by finding that Air New Zealand management had been engaged in a conspiracy, an accusation which they determined was not supported by the evidence. In its judgment, delivered on 20 October 1983, the Privy Council therefore dismissed Mahon's appeal. Aviation researcher John King wrote in his book New Zealand