pattern, thanks #24, re #14
Without an ILS GS a 'steep' approach path has to be constructed (NPA); altitude and DME, but with FMS VNAV it can be computed. A halfway option is to use FMS positions for distance, and manual altitude.
There was a previous thread reference to IGS, possibly a typo or that if FMS equipped, then the aircraft system is not authorised.
FMS could be used to 'enhance awareness' with position checks, often promoted by operators and some regulators, but this introduces an opportunity for error. The ease of FMS use, or misbelief in its accuracy, then it is used erroneously for the approach.
Perhaps this is a similar situation to incidents in
http://www.icao.int/safety/fsix/Libr...plus%20add.pdf
Still looking for confirmation if EGPWS was fitted in the aircraft opposed to the basic GPWS.
Good point about the type of ground prox alert.
Is the dash 8-400 cleared for steep approach GS, which would involve GPWS switching, but not required for a steep NPA.