Originally Posted by ampan[/quote
and appreciated that Erebus might be dead ahead,
Can anyone really say? Vette makes the case if Collins for even one second had any such concerns, when the terrain warning sounded he would have firewalled the engines. Vette's take here is that Brooks, seated farther back, began to experience the effect of full whiteout. But Collins may never have reached that stage, and may well have been convinced to the last second he was getting a false warning.
Originally Posted by DozyWannabe
The AINS is not normally subject to significant error (I think 2 miles was the max on a trip of that length), neither were any tracks being "programmed and reprogrammed every day".
The tracks are not being reprogrammed daily, but the coordinates entered into the AINS (I am assuming) was something done before each flight? By "more subject to error" I mean in terms of: 1) the kind of mistake that actually
was made; and 2) The fact that when entering the waypoints a pilot may inadvertantly also enter them incorrectly.
Would anyone else here care to comment on whether most pilots would regard AINS the way Vette does - as reliable as ground based instruments, and therefore an adequate substitute for an IMC let-down.
Dozy, would your views at all change if regulations had
required an actual
visual confirmation of landmarks - (in this case, including Mt. Erebus itself (or the clear absence of it) before leaving MSA, unaided by any help from or assumtions about AINS? Because I'm under the impression this is in fact the self-imposed mandate of many (most?) pilots.
Anyone: am I wrong here?
Finally, once beneath the clouds, Vette seems to be equating terrain that's "consistent with" what you would expect to see, with a "positive fix." For the benefit of us amateur nonaviators, How "positive" must a "positive fix" be?