Prospector says:
Not interested in what the legal people think, and not in a position to gainsay either the Law Lords or a senior law lecturer. All this happened long after the accident, and patently had nothing to do with the cause of the accident.
Right. So when you make the bald assertion “
If that is the opinion a senior law lecturer has of his peers in the Highest court in the land, than his opinion on anything to do with Erebus is surely to be taken with a shovel full of salt” which is plainly wrong and you get called on it, suddenly you are not interested any more.
Don’t blame me if your statement turns around and bites. It was you who made it.
And continues:
Could you explain what is your interpretation of what Mahon means when he states in his book "Verdict on Erebus",
" But the official view, as represented by Civil Aviation, was that the aircrew had no authority to descend below 16000ft. On this point the evidence was very clearly to the contrary. The officer in charge of the Route Clearance Unit of the company was plainly authorised on behalf of the company to brief the aircrews, as he had in fact done, by indicating that the aircraft could approach McMurdo at any altitude authorised or directed by the air traffic controllers at the American base."
As has plainly been shown many times the descent was requested VMC, and as stated many times VMC descent involves own responsibility for terrain clearance and avoidance of other traffic. The crew were never "authorised or directed" by the controllers for any descent, they obviously would have had to been identified on radar before such authorisation or direction could be given. They were never seen on the radar let alone identified.
Sure. Let’s look at each point you are asserting:
1.VMC descent involves own responsibility for terrain clearance and avoidance of other traffic.
Agreed.
2.The crew were never "authorised or directed" by the controllers for any descent
Wrong:
From the CVR
Shortly before 1.32pm the aircraft reported on H/F: “Still nothing [on VHF] – we’d like further descent – or we could orbit in our present position which is approximately 43 miles north?”
McMurdo: “Roger –
VMC descent is approved – and keep Mac centre advised of your altitude.”
(and later)
McMurdo: “New Zealand 901 – maintain VMC – keep us advised of your altitude as you approach McMurdo – report 10 DME from McMurdo.”
Aircraft (at 1.45pm): “We are now at 6000, descending to 2000 and we’re VMC.”
You cannot claim that was not a request for, and approval of, a descent.
3.they obviously would have had to been identified on radar before such authorisation or direction could be given
Wrong again.
a)On 8 November 1979, Captain RT Johnson issued a revised descent restrictions memo removing the requirement for ASR to be available and used for descent below FL160 (item 3 of the original memo exhibit 1/8). There was now no company requirement for radar monitoring if the descent was VMC
b)McMurdo ATC initially offered a cloud break descent under radar control when within 40 dme, but when New Zealand 901 said they could descend VMC, McMurdo ATC said in effect “Go for it – keep us advised of your level and report 10 dme. (see CVR record above)
4.They were never seen on the radar let alone identified.
Debatable.
There was an analysis of the flight path that showed that the aircraft would have been in line-of-sight of the radar for a period of about 30 to 60 seconds while descending in the right hand orbit. This time coincided with McMurdo ATC’s request to squawk 0400. The telex message when the flight was overdue reported the last estimated position as 38 miles due north of McMurdo when the CVR shows that the flight never reported any 38 mile position. Then there is the “accidental erasure” of the last 4 minutes 42 seconds of the ATC tape. This gave rise to the theory that McMurdo ATC saw the aircraft on radar, tried to warn it, but transmitted on VHF only and was not successful. Justice Mahon decided not to open this particular Pandora’s box and it remains an unsubstantiated theory.
So, in answer to your question, I totally agree with Justice Mahon when he says “
The officer in charge of the Route Clearance Unit of the company was plainly authorised on behalf of the company to brief the aircrews, as he had in fact done, by indicating that the aircraft could approach McMurdo at any altitude authorised or directed by the air traffic controllers at the American base."
Conclusion:
New Zealand 901 plainly asked for, and was approved for a descent that was completely in accordance with their briefing authorisation.