prospecter,
I came to read Vette's book before talking to pilots, and I have to say he had me convinced. It was only later that I felt I could not defend my positions while debating with pilots on another forum. It actually took me quite a while after the fact to accept this. Vette glides over the issue of whether INS is suitable for descents below MSA by never even alerting his readers to the objections we have seen again and again on this thread. Interesting that he notes how Collins was very careful to stay on the programmed track even after he was visual -
"It is an [in]escapable conclusion that Collins believed that there was some inherent protection or safety provided to the aircraft by its adherence to navigation track. There is no other explanation for adhering to it while flying visually."
(p135)
Vette may be trying to point out how carefull Collins was, but Collins' keeping to the track might also be interpreted as indicating that he wasn't really prepared to go it eyes alone?
So let me play the other side for a moment. Part of Collins' certainty must have rested on the assumption that even in the unlikely event they were off course, he would be in VMC once under the clouds, and that fact alone would count as certainty of terrain avoidance. Except for the unanticipated effects of white out, would this normally have been a sound assumption?
Thank again.