Prospector:
Ron Chippendale may have great credentials and produced a magnificent report, but I think that he got it wrong
The probable cause of the accident was the decision of the captain to continue the flight at low level towards an area of poor surface and horizon definition when the crew were not certain of their position, and the subsequent inability to detect the rising terrain which intercepted the aircraft’s flight path.
Captain's decision? Pilot error? Pigs a*se!
It seems pretty obvious to me after reading the reports, as you so kindly instruct us to do, that the crew knew EXACTLY where they were – they were flying down the middle of McMurdo sound AS PLANNED because
a) They were ON TRACK according to their INS and
b) they were MAINTAINING VMC and could see the cliffs of the shoreline in the distance on either side and the broad flat expanse of snow and ice in front of them.
c) CVR: “Where is Erebus in relation to us at the moment?” “Left, about 20 or 25 miles…about 11 o’clock.”
However, some six hours before departure the coordinates of the destination waypoint were changed by ANZ navigation section and
MCMDO MCMURDO 7753.0S16448.0E 188.9 (the track) became
MCMDO MCMURDO 7752.7S16658.0E 188.5
THE CREW WERE NOT INFORMED OF THIS CHANGE and this was fed into the nav system. Chippendale did not seem to think this was significant. !
So, in actual fact, the crew were 27 miles to the east of where they (and McMurdo ATC) thought they were. What they took to be the cliffs of the shoreline of McMurdo sound were actually the cliffs of the shoreline of Lewis Bay. Mt Erebus was in front of them, but invisible in the sector whiteout. They reacted within 5 seconds of the GPWS going off, but could not outclimb the slope.
Prospector is a bit selective in his memory too
Gordon Vettes investigations attempted to show why they never saw Erebus, not why they were down at the altitude they were.
They were down at that altitude because it was legal. (Regulation 28 of the New Zealand Civil Aviation Regulations) The 6000/20 was a COMPANY sector safe altitude used in the application for route approval. It had not been complied with by any of the flights in the previous 2 years. Flying at low level had the tacit approval of the company and featured in many publications including their own magazine. The air traffic controllers at McMurdo had never been advised of this company requirement. They were well known to be happy to issue a clearance to descend in VMC to an aircraft tracking down the middle of McMurdo sound, as this was the inbound RNC route used by the military traffic and designed to keep clear of high terrain.
Bloodshot VFR at 1500ft, 260 kts, in an area that neither of the drivers had ever been to, and the CVR recording of uncertainty as to position, this was the fault of the company??
CVR recording of uncertainty as to position??. Crap. They had re-engaged NAV tracking after the descent orbits. They were certain of their position. The only problem was that they were wrong.
CVR extracts:
(Air Disaster Vol2 - Macarthur Job)
00:45:00z “Now at 6000, descending to 2000. VMC
00:46:39z “Where is Erebus in relation to us at the moment?” “Left, about 20 or 25 miles…about 11 o’clock.”
00:47:43z “Might have to drop down to 1500 feet here, I think”
00:48:46z “Actually, these conditions don’t look very good at all.”
00:49:24z “I don’t like this.”
00:49:30z “We’re 26 miles north. We’ll have to climb out of this.
00:49:40z GPWS
00:49:49z “Go-around power please”
00:49:50z Impact
It seems very convenient for the airline that the document recovered from the wreckage referred to the company sector altitude which was not complied with. Strange that the briefing documents showing the original track down McMurdo sound were not recovered, although Capt Collins family knew he had plotted the track himself on an old school atlas for his own information. A company representative went to the home of F/O Cassin the day after the accident and recovered his briefing documents and they were (surprise!) never seen again. Later investigation just happened to reveal that all briefing charts showed a track down McMurdo Sound to the west of Mt. Erbus.
On January1 1980 the CEO Mr Davis denied reports that the destination coordinates had been changed and the crew not told (a lie) and asserted that when the aircraft left Auckland the correct coordinates had been in the computer system of the aircraft. (true, but…)
The Royal Commission report said
In my opinion… 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 Mount 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.
The part of Justice Mahon's report that will forever be remembered despite protestations of airline innocence will be
The palpably false sections of evidence which I heard could not have been the result of mistake, or faulty recollection. They originated, I am compelled to say, in a predetermined plan of deception. They were very clearly part of an attempt to conceal a series of disasterous administrative blunders and so, in regard to the particular items of evidence to which I have referred, I am forced reluctantly to say that I had to listen to an orchestrated litany of lies.
Justice Mahon’s report was later overturned, which was very nice for the government owned airline. But as they say, you can’t beat city hall. The New Zealand government must have been kicking itself for breaking a fundamental political rule: Never have an inquiry if you cannot determine the outcome in advance as it is so difficult and embarrassing to have to get things reversed.