Originally Posted by
dClbydalpha
The thing I can't get my head around is either
1) why there was no terrain warning.
2) if there was why it was too late or ignored.
Did you see my comments earlier in the thread, that state that for the Mk XXII EGPWS the look ahead alert envelope shrinks below 100 KIAS and is inhibited below 70 KIAS? I'm not saying that is what happened, but it lends itself as an explanation.
Page 17:
http://skybrary.aero/bookshelf/books/3018.pdf
The MK XXII uses turn
rate and direction to predict the aircraft flight path in the turn
and “looks around the corner” for terrain/obstacles. Forward
airspeed will also modify the look-ahead envelope. Below 100
knots, the envelope is reduced until it is completely inhibited at
70 knots or less. The preceeding speeds are for "fast" helicopter
configurations, "slow" configurations use the range 90 knots to
60 knots for envelope reduction