Originally Posted by
dlen
Wouldn't it be possible to just measure the nose up tendency - be it caused by engine nacelle lift or thrust at low speed - by evaluating both pitch change rate and control column position, and apply ND trim accordingly?
Pitch and AOA are not the same. Pitch and AOA can change independently during maneuvers, which is why tracking pitch changes will not help determine rates of AOA changes, nor will it help determine the absolute value of AOA. In order to do this properly, you need a full blown computer system that integrates all of these sensor inputs, plus GPS, airspeed, etc. Those are fitted in an A350 or B787, and their price is more than twice that of a B737.
Originally Posted by
derjodel
AP disengage when AoA disagree.
Someone should write a thread showing all of the things that do not work when there is AOA disagree. IMO it would also simplify checklists if there were a single comprehensive one for AOA disagree, instead of parts of other checklists for procedures which bear some relevance to the actual flight conditions.
Edit: @
ecto1 IMO Boeing needs to produce some hard data about how the trim system actually operates under real world conditions, not how manuals written in 1968 say it should work.