Do we agree that it is impossible for a passenger airliner to be at FL 350 with an airflow <60kts passing over the Alpha probes (from whatever direction)?
Heck no
! All you need is a bit of ballistic trajectory and any value is possible.
Any AOA sensor that requires 60 knots to read local airflow direction should be trashed. That criterea is way too high. I tested several former airline and military AOA transmitters a while ago by sticking them out the car window and noting my 'ground speed'. They were alive by
15 to 20 mph.
HN39
IMHO when stall warning is active it should not stop when the AoA becomes invalid but should continue to sound until a valid AoA signal indicates an AoA value less than the stall warning threshold value.
I agree fully. Just have a procedure so that you can kill an AOA sensor in case you learn while airborne that someone rammed it with a baggage cart or that it is frozen. With multiple sensors onboard, you do have redundancy. It is quite possible to detect and report sticky AOA motion with an arrangement such as the Airbus has.
That is a design feature that Airbus needs to look at. How long was AF447's #1 AOA sensor sticky? A day? A month? A year? Who knows?
My biggest beef with the Airbus ADR design is very fundamental. Airspeed indications should not influence AOA indications in any way. They are fully independent parameters. Why allow one defective parameter to silence a good one?