Originally Posted by
Dream Land
My point is that I am trying to make is that the tour itself was not something conducted by use of any company supplied fixes if I am understanding the information correctly.
That was the case in the days before the computerised flight plans, certainly - but from 1978 onwards, when the computerised flight plans were followed, things became less certain. With the passage of time the Antarctic flights stopped being a preserve of the management captains who had drawn up the original process, and passed to the line. Prospector, who appears to venerate the abilities of the management pilots of the day as being somehow superior, sees this as the point the rot began to creep in (and blames the union) - whereas I see the fact that the transition was not properly managed as a failure of management in terms of putting a process in place to transfer the knowledge. With the computerised flight plans in place it seems to have become the
de facto practice to follow the computer track for as far as necessary before visual flight can be begun, and the fixes on the computer track did indeed come from the company - they were entered by Chief Navigator Hewitt himself.
Captain Simpson noticed that the waypoint labelled "MCMURDO" was a significant distance from the station - prior to this the assumption had been that the waypoint had been selected to follow the military track and did not refer to the station itself. He reported this upon his return and the message was passed up the chain to Hewitt, whose testimony states that he reset the waypoint to the TACAN, believing he was making a correction of 2 miles of latitude rather than the 27 mile correction he was actually making. Whilst he never went into specifics we can only assume that he made the change whilst looking at his original notes rather than what was in the database itself, which would have revealed not the 2 mile error he was expecting due to mistranscribing, but a 27 mile error which appeared as a consequence of his mis-typing the co-ordinates a little over a year previously. In any case he did not notify ops of the change and the fact that the co-ordinates had been changed was never communicated to the pilots who he would (or at least should) have been aware would be flying the route that morning.
The ethics of Hewitt's actions are debatable depending on how sympathetic one is to his account, but in strict terms his actions were a clear violation of company procedure as well as common sense and they were performed before the flight crew even awoke that morning.
What follows is a classic case of organisational entropy, which in this case had many tendrils manipulating events.
Firstly, the
de facto procedure of following the computer track until visual flight was possible meant that in a situation where visual flight below an overcast was the only available option (I don't buy the assertion that every preceding flight occurred in "gin-clear" conditions throughout - even if the flights were scheduled for the best weather possible, we're talking about Antarctica here and the weather is anything but predictable), the pilots would be relying to some extent on the AINS and radar to confirm their position before descending - and would not be aware that the topography of Lewis Bay could from certain angles be mistaken for that of McMurdo Sound. Because these flights had been going on for some time they had become perceived amongst the flight crews as somewhat routine, and this led to a further perception that the computer would keep you away from high ground if the programmed track was followed.
Next we have the clarity of the briefing becoming diluted over time - rules became guidelines and the potential dangers that may have been well understood by the early crews were not properly communicated to those that followed. The audio/visual and written materials that dated from the earlier flights were verbally contradicted during the briefing itself, with the verbal instructions taking precedent - and this was explicitly confirmed by the briefing pilot's testimony.
Finally, we have the breakdown in communication between management, nav section and ops. Nav section clearly did not query the fact that the returning flights from Antarctica were following a track that was considerably different from that which they testified was intended. The error was only brought to light by chance when a line captain (Simpson) informed his superior on his return of the apparent discrepancy. The message certainly reached Chief Navigator Hewitt, but it would appear that neither ops nor management heard of it, nor was there a co-ordinated effort to solve the problem. Hewitt therefore made his change without notification or supervision in the early hours of the morning and no thought was given to the potential consequences of such a change.
These circumstances combined in such a manner that only a large dose of luck might have been able to help the crew of TE901 realise their predicament, and sadly luck was certainly not with them that day.
@ampan - How often would one have watched a transponder light in those days? It only needed to be on during the few seconds during which a decision was made to have proved fatal. Sector whiteout was understood by polar aviators, but not by line crews - or indeed even the management pilots that prospector speaks so highly of, because Gemmell certainly did not appear to understand the phenomenon judging by his testimony. Let me check the transcripts on the "40 miles" and get back to you.