@HazelNuts39 Post #1308, Thread Seven.
[/B] Thirty knots drop of IAS in one second is not sufficient to identify UAS. It is not inconceivable that it would occur as a real change of airspeed in a windshear/downburst close to the ground or in the vicinity of the jetstream at altitude. Considering the multitude of possible causes and flight conditions, IMHO the computers cannot reliably identify UAS, but must leave the diagnosis of the problem to intelligent humans. [/B]
2:10:05 ( 04.6 ) : AutoPilot drops out
2:10:06 : "I have the controls"
2:10:10 : STALL/STALL
2;10:14 : "We haven't got a good display,,,"
2:10:18 "...of Speed"
As simply as I can, I note the Pilot is Flying one second after loss of Autopilot. Per the chronology (above) he is doing so without benefit of 'Airspeed' display. Airspeed is a result of controls input, so he begins with a RESULT, not a condition. The result on which he is to base his manual input is verbalized, we assume it is the most important thing to him as well.
For thirteen seconds, he flies not knowing airspeed, and we also assume he doesn't know why airspeeds are bad. Like it or not, he has flown the most important part of the flight of his life, without identifying the problem that will destroy his aircraft. Now well and good, but I will offer a defense.
RR_NDB
Ebb, Flow, Consistency, Continuity. A dynamic condition cannot be entered (looped) ad hoc. We think the a/p was lost due as simple as GUSTS? So in reality, the AIRSPEED WAS NOT UNRELIABLE. It was accurate, and caused the a/p loss. Hazelnuts39 post is instructive, but it is my inference, not his. Much of the original debate on the very first thread had to do with Pilot Flying, and his Awareness.
I posited long ago that the autopilot may have been lost due to simple limit/exceedance. as did many others. Then the argument devolved to LAW, and got ever more arcane from there. Thence to STALL.
The idea in controlled systems is Seamless Transition. With seams, important stuff can fall through. If not UAS, then there is the possibility of Pilot Flying believing he is (remains) in NORMAL LAW, and his zoom becomes rather vanilla flavored, and more understandable.
The autopilot quitting becomes what esteemed members have said: not a big deal. The DEAL was Pilot unawareness. If he was piloting without an awareness of the controls degrade, then we have liftoff. The LAW degrade was annunciated at 2:10:22. 17 seconds after cause, and well into effect.
Facility, Systems, Flow.
Last edited by Lyman; 7th Apr 2012 at 16:39.