IRREFUTABLE FACT:
Mahon observed that ‘the occurrence of any accident was normally due to the existence of a variety of factors’. He asserted that in this case there were 10 factors; the disaster would not have occurred had any one of them not been present. But he then went on to describe a single cause of the disaster:
In my opinion therefore, the single dominant and effective cause of the disaster was the mistake made by those airline officials who programmed the aircraft to fly directly at Mt Erebus and omitted to tell the aircrew. That mistake is directly attributable, not so much to the persons who made it, but to the incompetent administrative airline procedures which made the mistake possible.
He disagreed with Chippindale’s ‘probable cause’ that the pilot was at fault, and cleared the crew of any responsibility for the accident. The blame lay squarely with Air New Zealand.