Part II: Air Canada, too low on...

[westhawk]

PJ2:

Thanks for the info, it inspired me to go look at an old Honeywell EGPWS pilot's guide applicable to the Hawker 800XP I used to fly. Indeed it appears that between 4 and 12 miles to the runway center a terrain warning would be issued only if the airplane had reached 400' AGL or if any terrain/obstacle penetrates the caution ribbon. (predictive terrain clearance)

So in this case it appears that the ATC radar low altitude alerting feature provides a considerably earlier warning than the EGPWS would have. I've seen a few nuisance low altitude alerts in my time but this one appears to have kept a premature descent from becoming a much closer thing.

For the types I'm experienced in I have pretty good idea how this scenario can occur because I've either seen or committed some of the errors possible. Fortunately effective error trapping made these occurrences non events, but eventually even the most effective SOPs break down for various reasons. I look forward to reading what a pilot with experience in this particular type might have to say about what equipment specific input errors might be likely to lead to such an occurrence.