Originally Posted by
safetypee
Check Airman, see the presentation on
AoA research which concludes “that we probably do not need a display”, “little of no use when approaching the stall”. There are strong arguments re rule and knowledge interpretations of AoA displays.
Note that the display formats were research orientated, but they do identify the difficulty in creating an intuitive display, e.g. compare the gauge with the indexer (S7 and S8), which way to push?
Villas, the presentation also shows some of the difficulties of trying to ‘looking through’ the FD with EFIS.
Modern display formats tend to ‘box in’ visual attention toward attitude and thus towards the FD; – Gestalt where the visual interpretation will perceive a boundary even if not actually present.
Many old style displays had a true 3D construction; EFIS is a 2D depiction of a 3D system – no depth in the perception; thus more knowledge based effort is required to ‘look through’ an EFIS FD than with a mechanical instrument.
There are similar problems with instrument scanning.
I find it hard to imagine that a flasing red box on the pfd would be totally ignored. If you're looking directly at AoA data, it must be easier to recognise that you're in a stall, and then take action.
The presentation didn't detail the experimental methods used to come to the conclusion that the direct AoA readout is ineffective. I'd like to see that data.