Originally Posted by
Check Airman
...
Design flaw?
Lastly, one can hardly blame Airbus for making 60kt the stall warning cutoff. How could someone foresee a situation where an airplane of that size would be in the air at that speed? I’m willing to bet that that feat has not been replicated.
The flaw I can see is that in a fully automated plane the secondary mode for primary sensor failure should be secondary instruments, which the pilots are supposed to rely on already - a pitch and power schedule. If they are good enough in a black-out instrument only flight for the pilots why would they not be sufficient for the automation? Add in some monitoring of the altitude to close the loop on power and it should do better than the pilots can.
Certainly at some point the ice melted to give reasonable airspeed values and then the descent rate can be combined with it to give an approximate AoA to validate against the AoA sensors; was there some reason Airbus chose not to do this? Instead of WoW perhaps a non-zero descent rate could be the way to validate the AoA?