Hazelnuts39
The ADIRU determines the vane angle from the sensor 'resolver' values. Possibly it applies a calibration of vane angle vs body angle of attack for the flap/slat configuration. If the airspeed is less than 60 kt CAS, the ADIRU transmits the value NCD (No Computed Data) instead of the AoA value (as I understand it). The stall warning function resides in the FMEGC which uses the AoA values it receives from the ADIRU's.
HN, the logic and function of the stallwarning is understood. The question after AF447 is, wether this arrangement to use the speed signal as the only authority to verify the correctnes of an AOA over the total AOA regime is a clever one. I can understand that some input like speeds are necessary to compute the exact angle of attack. But what sense does that make in extreme AOA conditions, where high raw AOA data show the jet in the stalled condition anyway? Why not implement a logic, where an AOA value above the highest stall onset AOA bypasses the above logic and thus keeps the stall warning active? it cant be rocket science to do that.
To clarify my thoughts a simple example out of daily life. I'm wearing glasses like many people do. When i enter a moist room coming from the cold outside the glasses fog up. Instead of closing my eyes and being blind it has itself proved appropriate to remove the fogged up glasses and work with whatever eyesight is left.