Originally Posted by
prospector
Really? the only record appertaining to descent was that a VMC descent was requested, as you are no doubt aware that makes the crew responsible for their own terrain and traffic clearance during the descent requested.
I know Gordon Vette in his book Impact Erebus states that his (Collins) transponder was coding, but I find it very difficult to understand how this could be ascertained by anyone who was not in the cockpit at the time.
You'd have to take that up with him, but requesting a VMC descent under radar guidance would be a very different kettle of fish from doing it without, and a whole different set of rules would apply, would it not?
One would think if they were indeed on the radar then their VHF and DME would also have been giving a reading.
From what? The NDB had been withdrawn the year before, and the TACAN would have served no purpose until the left turn south of Ross Island had been made - in fact you can hear them discussing dialling it in on the CVR.
The question of McMurdo Radar was very well covered by Judge Harold Greene's hearing in the US District Court in Washington who wrote in his ruling..."
The Americans had their own vested interest in the case, don't forget - the "small matter" of five minutes of radar records that were destroyed some time between the time of the accident and the inquiry.
Really? after requesting a VMC descent? naughty naughty.
Not really - the cloud was patchy until reaching the area of Ross Island/McMurdo - enough for a VMC letdown, and Beaufort Island is not that large from 16,000ft. Look at the track graph - the published letdown has them rejoining the track south of the island, and they'd have been looking ahead. Once under a certain altitude, the logical visual fixes were Cape Bird, Cape Bernacchi and Cape Royds - which they thought they saw (but in fact were looking at Cape Tennyson on the left and Cape Bird on the right).
Are you trying to say that McMurdo radar could see through Ross Island and Mt Erebus? That must have come from the Holmes account, from where else could it have come?? Not even Mahon came up with that proposition.
No - I think they were being tracked on radar at the start of the descent, and somewhere toward the end of the descent radar lost them, and they went out of radio range because Erebus was now in the way. The transponder may have continued coding for some time after then to re-establish contact, leading them to believe they were on radar until shortly before impact. The note of concern raised by the flight engineer and Collins related to the fact that they had lost radio contact and nothing more. I do not believe Chippindales assertion that they were in cloud.
Delete all reference in briefing dated 23/10/79. Note that the ONLY LET/DOWN procedure available is VMC below FL160 (16,000ft) to 6,000ft as follows.
1. Vis 20 km plus.
2. No snow shower in area.
3. Avoid Mt erebus area by operating in an arc from 120 Grid through 360 Grid to 270 Grid from McMurdo Field within 20nm of TACAN Ch29.
4. Descent to be coordinated with local radar control as they may have other traffic in the area.
And they had every reason to believe those boxes were ticked. Below 2,500ft Mac Central posted 40km visibility, no snow, they believed their INS track was headed into McMurdo Sound and they thought they were on radar.
This is the reason that I have a hard time finding the crew responsible in the legal sense - because of the presence of weather conditions on which they had never been briefed, they made the best possible decision they could with the information presented - that the information was erroneous because of such conditions at that particular time and in that particular place, there exists reasonable doubt that they could have known it was erroneous even if the nav track had not been altered, or if the track was down McMurdo and an INS error had misdirected them. They knew that the INS was accurate to more or less two miles on that route, so even if an INS error had taken them off-course they would still be over McMurdo Sound.
If this was a one-off flight planned with the military-like precision that Chippindale seems to have expected then I'd have more truck with his conclusions, but as it is, ANZ had been treating the flights as more-or-less routine and had infact been gradually removing more and more of the safeguards that were supposed to protect their flights.
In view of the mandatory descent requirements printed above, which were required to be complied with both by the company and CAA, and the lack of credence given these requirements by Mahon, I find that statement hard to digest.
As hard to digest as I find Chippindale's assertion that they were in cloud when that contradicts the contemporary weather report as well as the data later obtained by Vette.
Now - please don't be offended, but I want to ask you an honest question. How much of this do you really believe in your own heart, and how much of your vehemence is attached to a belief that to think otherwise is to automatically denigrate the work of Chippindale - a man who is no longer with us that you clearly respect?
I posted a few paragraphs in the AH&N thread on why I believe this to be a false dichotomy which I won't repeat here, but suffice it to say that I think that Chippindale honestly believed in what he was saying and I don't think he was intentionally out to deceive - I believe that this is why Mahon went out of his way to call him a model witness even though he clearly was not convinced by the conclusions he made. However I do believe that his employers at NZCA had a vested interest in an outcome of pilot error, because they had failed to update their regulations in accordance with ANZ starting to take on sightseeing flights - the regulations up until that point only really suitable for regular line flying (and the changes they did make were repeatedly flouted by ANZ over the two years between the start of the flights and the accident). I also believe that ANZ only presented the evidence to Chippindale that they wanted him to see (Ironically doing to Chippindale what the whiteout did to Collins) - going to some lengths (including B&E!) to conceal their own lowering of standards regarding Antarctic flights between 1977 and 1979. Chippindale himself admitted in 1987 that he believed ANZ pulled the wool over his eyes regarding how the Antarctic flights were operated, but at the same time said that did not alter his opinion.
Where I have a harder time explaining his actions relates to his editing of the CVR transcript, which in itself broke almost every known protocol relating to CVR handling in accident investigation, but in particular inviting Captain Gemmell - a known party with a vested interest in the conclusions of his report - to listen to the tapes with him. That, to my mind, was inexcusable - but I'm willing to accept that was down to naivete rather than malice.
Those that come down on Chippindale's "side" tend to have a belief that Captain Vette's research was largely to clear the name of his good friend Captain Collins, but he himself has never been that clear cut. What he said at the time of the Mahon report was actually that he believed that given the way ANZ were operating those flights at the time, presented with the same whiteout conditions and with the nav co-ordinates changed without their knowledge - any of ANZ's pilots, including him, would have ended up on the slopes of Erebus. That in itself is a pretty big admission to make, given that he was no slouch at navigation himself (having famously helped navigate a lost Cessna pilot some time previously).
For all my opinion is worth (which admittedly isn't much), if ANZ had not changed the co-ordinates and briefed the pilots correctly on whiteout, then I'd have been willing to accept some responsibility on the part of the crew. The corollary of that is that I believe that if whiteout had been briefed correctly and the co-ordinate change had been either notified or not made until after the Collins flight, the accident would never have happened.
Thus as far as I'm concerned (and given the deliberately destroyed evidence on the part of Mac Central and Air New Zealand), I have to apportion the responsibility as 15% NZCA for failing to update their regulations and failing to keep a regulatory eye on ANZ between 1977 and 1979 as far as Antarctic flights were concerned, 5% on Mac Central for destroying exculpatory evidence (which leads me to believe they were not paying attention to their radar), and 80% on Air New Zealand, for allowing standards to slip so spectacularly within the space of two years, having incredibly lax communication protocols between their nav section and operations and changing the INS co-ordinates without the crew's knowledge.
Furthermore, I believe that Prime Minister Muldoon deliberately engineered the political split and media manipulation that fostered an adversarial relationship between members of the NZ aviation community in an attempt at damage limitation on the reputation of his national carrier, which he knew would have been in considerable financial difficulty were it not for government subsidy.
@FGD135 :
The Mahon findings are right here:
http://www.erebus.co.nz/Portals/4/Do...f Disaster.pdf