Fantome ,
" In which regard, it becomes manifestly clear,"
I would agree with that statement but for entirely different reasons. Here is the first one.
The requirements for descent were very clearly laid out, very explicit, and for the reason that the lack of Antarctic experience of the Air New Zealand crews was well known. The required conditions were as follows.
Delete all reference in briefing dated 23/10/79. Note the only let-down procedure available is VMC below FL160 to 6,000ft as follows:
1.. Vis 20 km plus.
2. No snow shower in area.
3. Avoid My Erebus by operating in an arc from 120'Grid through 360'Grid to 270'grid from McMurdo field, within 20 nm of TACAN CH 29
4. Descent to be Co ordinated with local radar control as they may have other traffic in the area.
The reported weather at McMurdo base was well below that required for the approved descent procedure. That is why they invented their own.
Not one of the required mandatory requirements for descent was met. They did talk to the radar operator, but they were never identified on the radar.
At no time did they have a DME lockon to TACAN channel 29.
At no time were they in the required arc from TACAN Ch 29 for the approved descent.
The argument that the waypoint had been changed would have had no such serious repercussions if these mandatory requirements had been complied with.
But, even if the aircraft was where the crew thought it was, in the weather conditions that they considered were good enough for a VMC descent, why was it that nobody twigged that they were on the wrong side of Beaufort Island, a very distinctive Island that was visible, it showed in photo's recovered from the wreckage.
If they were so certain of their position during this descent why was it that Mulgrew, the tour guide, and supposed expert on things local for this trip told the passengers less than 4 minutes from impact
" I still can't see very much at the moment, keep you informed soon as I see something that gives me a clue as to where we are"
Even if they were where they thought they were,they were within 25 miles of a 13,000 odd ft mountain and they had never sighted it even once.
And the simplest confirmation of the lot, they had a lat/long readout from the INS that was exceedingly accurate, but at no time was this readout put on a chart before descent was commenced.
Previous flight had descended below the altitudes laid down, but they had all been identified, and position confirmed by McMurdo radar, and in the conditions they had Mt Erebus could be see from 100 miles or more.
This from Bob Thomson who had been down to Antarctica some 75 times, and some 50 times on the flight deck of aircraft approaching from the North. He was the usual commentator on Air New Zealand flights to the ice.
Taken from John Kings New Zealand Tragedies, Aviation.
"The captain didn't give any attention to problems that he might have around there. These people were taking a Sunday drive. When I heard the transcript of the CVR I fell out of my chair. Most of the times Mulgrew had been there he had gone in by sea, and all his travel from Scott Base was to the South. Hardly anybody ever went into Lewis Bay.
Had they orbited Ross Island they would have seen the the cloud. If a pilot is unsure of his position he always goes up, never down. The co-pilot of flight 901 never opened his flight bag to look up the co-ordinates. I always had a chart in the cockpit and checked the latitude and longtitude readout, but the crew of the fatal flight never referred to it."
And that sums it up, as to the cause of the accident.
PS "the input of experts such as Gordon Vette," How many trips to the ice does it require to be termed an expert??? How many trips to the ice had Gordon Vette carried out??
Last edited by prospector; 13th Sep 2011 at 05:27.