Golf Sierra
The Navy aircraft I referred to earlier get around that with units ... not sure if that is applicable for transport aircraft.
Good points, also the understanding that AoA and stall AoA are not fixed values, but vary as you point out.
I am not sure I understand this.
The Airbus FCOM states that in case of a simultaneous OVERSPEED and STALL WARNING the stall is to be actioned - failsafe: if a pitot fault gives us an excessive speed the alpha-max will decrease, so if we follow the stall warning we basically end up flying a lower AoA then would otherwise be possible. But the 'under-speed' scenario does not seem to be addressed too well.
By "otherwise possible" do you mean "allowed by the protections" or physically possible? Is alpha max a computed value, or is it the raw AoA measured by the AoA probe?
My point is, if you have a false airspeed indication, the AoA probe/detector doesn't give a rat's behind. It is measuring something other than dynamic pressure, and if I may say, it is measuring something simpler: angle of airflow relative to the aircraft. (Or should I say airfoil?) Of course, if the AoA probe gets stuck/frozen rendered moot someway, then ... well, that's another dog's breakfast served to the flight deck crew. (Gee, it goes back to pitch and power again.
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EDIT: yes, there are two different hydraulic boost systems that help the mechanical linkage move the THS.
This picture purports to show A330 AoA probes, which look a lot like AoA probes I've seen on other aircraft. They do not measure what the pitot probes measure. What appears to happen inside the computer in the A330 is that airspeed input is compared to AoA probe reading is compared to other data and, once the calculations are done at the speed of electricity, visual cues are presented on the strips (vertical) next to the pilots attitude indicator on his flying display.
(VLS/V alpah prot V alpha Max)