gonebutnotforgotten:
That shows neatly how Stall Warning incidence is a function of Mach Number, so when the ADRs went belly up, what happened to the M input to the stall warning system, and what did the latter think the corresponding warning incidence (AOA) should be? Does it use the last valid IAS/M value as the rudder limiter system does?
I looked at HN39's graph.
What you say in re stall as "a function of Mach number" seems to me "correlates to Mach number," since the stall approach, condition of stall, and warnings, (unless I misunderstand the system) are triggered by a signal from the AoA sensing system.
AoA sensing subsystem is independent of the Airspeed/Mach sensing sub system. The computer receives signals from both and uses various logic to reconcile them, which seems to be your further point, and a potential point of failure or ambiguity. (The clipping of AoA info below 60 kts has been discussed, pro and con, at some length in the Rumors Forum thread ...)
If I misunderstood your point, apologies.
bearfoil:
The lack of a fossil AH on the panel was a shorter discussion, as many were astonished to find that so 'common' an occurrence as 'Unreliable Airspeed' could (did) leave both pilots without attitude, or 'assiette' data, (display).
bear, what do you mean by a fossil Artificial Horizon? The ISIS back up display has a back up AH. As yet, no evidence that the AH's embodied in the glass cockpit displays (for basic flying instruments I note above to Clandestino) were other than functioning per spec.
I are confused at your point there.
