I assume that “give it a rest” is directed at this McNeish person. Megan need not worry, because on the back of the book, above the “Whitcoulls $34.99”sticker, appears the following: “A master of tone and a warrior of words, Sir James McNeish is one of New Zealand’s literary greats. He died in November 2016 after handing in the manuscript for ‘Breaking Ranks’, which became his final work, and is destined to become a classic of New Zealand non-fiction.” At least Captain Holmes had a go. This pathetic “literary great” did not. He was either too lazy, too thick, or too concerned about offending “Bernard Brown, Parnell. A friend” - and an acquaintance of Mahon from the Auckland University Law School and the creator of the strange rambling epilogue.
BernLagen: The device that you’re referring to was one of several navigation aids. Its role was to get the aircraft across the Southern Ocean, which it did. The particular navigation aid was not to be used to go below the height of a nearby mountain, because the navigation aid might be wrong, and the plane might hit the mountain. Jim Collins knew that the navigation aid was not to be used to go below the height of a nearby mountain but he did so nevertheless. The navigation aid was wrong. The plane hit the mountain.
The only thing that might be argued with in the above is the navigational status of a 1970s inertial navigation system. I’ll leave it to Gordon Vette:
"Left alone to fly at 35000 feet, the three inertial boxes and their computer would take them unerringly to McMurdo, turn around and bring them home. But this was certainly not the trip the passengers had paid for. The machine would need to descend soon after it passed the Cape Hallett corner, and continue descending near high land masses until it reached the McMurdo waypoint at the head of the sound. The high altitude reliance they placed on the Area [Inertial] Navigation [System] would revert to more complex and time-consuming methods; radio beacons including Distance Measuring Equipment, gyro compass, grid navigation and most importantly, visual flight. … Like any good pilot, Collins would certainly have made up his mind that unless visual conditions were good,there was no way he would take the aircraft below Minimum Safe Altitude (MSA) of 16000 feet. MSA constitutes a platform for pilots. Once below it they leave behind the self-sufficiency of the inertial navigation system and commit themselves once more to guidance from aids on mother earth, and to visual flying – ‘eyeballing’ in pilot jargon." (‘Impact Erebus’ pp118, 119)
Were it not for the errors made by the navigator in the cockpit, the errors made by the navigators on the ground would not have mattered. Data-entry mistakes in internal navigation systems had occurred throughout the 1970s and the possibility was widely known ,hence Vette’s remarks.
I suspect that Mahon thought himself to be very clever in heaping praise on the accuracy of the DC-10’s top-of-the-range three-platform inertial navigation system. But in doing so, he forgets what happened: The top-of-the-range three-platform inertial navigation system was wrong, and the place hit the mountain.