Originally Posted by
Realbabilu
I understand from having read earlier in the thread that both AoA sensors are used but only one at a time, on alternating flight legs, between the left & right FCCs which are fed by the left & right AoA sensors respectively. It's
still a single-point-of-failure issue and as has been stated numerous times throughout this thread, that design requires an answer as to why.
For airline pilots, particularly non-military-fighter types, AoA is a secondary piece of information. If AoA is to be implemented, then mental habits have to change to accomodate a new way of viewing the wing. One cannot make both airspeed and AoA equal in the pilot's mind due to the obvious potential for confusion. Airline pilots fly by speed not AoA, and introducing data on the PFD in an abnormal situation could be confusing in terms of a quick intellectual apprehension, (mental modelling), necessary for timely and correct decision-making. We are accustomed to "obeying" airspeed, not AoA and when the priority suddenly becomes "AoA over speed
or pitch", even though perfectly correct, may in a rapidly unfolding situation which is becoming more confusing by the second, render AoA of dubious value.
This is not to dismiss AoA itself as valuable; out of interest, I used to watch it using the ACMS section of the rear MCDU on the A330/A340 when in cruise. But the modelling of behaviours necessary to make it become "primary" in pilot awareness when we've used airspeed as primary
forever, is a signifcant change which may not be necessary, for as I have mentioned before, recognizing and using AoA still doesn't have any "saves" to its credit in airline work. It
may have such a potential, but planning for or requiring its use is by no means straightforward, as just displaying AoA on the PFD or even installing a comparator does not resolve the question of which parameter to prioritize when AoA's don't match by a set value and set off yet another attention-getting device to which the pilots must intutively react, possibly swiftly.