Originally Posted by
CurtainTwitcher
MechEngr, how about the stick shaker noise, IAS disagree warnings going off at the same time? Which are you going to attend to first? The stall warning, a runaway stabilizer or airspeed unreliable?
ALL of these are memory items and needed to be attended to ASAP, and all are potential symptoms of an AoA failure. Not so simple is it.
Run this while trying to figure it out.
https://youtu.be/TrjTUvhpBlE
There is no "runaway stabilizer." That term I specifically avoided because it's subjective. Sometimes the trim runs. And then stops. If it reaches the mechanical stop was it running away anymore? Nope, it has stopped running. But I bet the control forces are too high. So deal with what the real problem is and not make the pilot make some guess. If STS trims too much or too little, pilots input manual corrections. Was that runaway? What if the trim runs for more than a few seconds but the control forces are acceptable? Is that runaway?
It should take less than 10 seconds to determine what to do about the stall warnings and that is independent of control forces. In both crashes there was only one-side with the error and the performance of the plane was unchanged, indicating the warning was false. Am I mistaken or is that not part of all 737 training for 20+ years? How old is the NG series? The ET302 disaster unfolded over nearly 36 times that time span.
Tweak away, but the AD instructions were terrible with only vague actions to take and weak symptoms to determine it was the correct procedure.