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Old 11th Mar 2019, 19:46
  #451 (permalink)  
wiedehopf
 
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Originally Posted by lomapaseo
If one assumes it is a known problem (LionAir type) then what part of the AD is not sufficient?

Is it the technical part or the compliance part?
In my opinion a AoA sensor failure is complicated enough to handle, but if you compound it with the MCAS mistrim it becomes deadly for some pilots.
(By the way a single pitot tube reading low speeds could lead to the same symptoms including stick shaker and MCAS, no?)

Suppose you have below average pilots coupled with mediocre or poor English skills who are not speaking the same mother tongue.
Disagreeing instruments, especially airspeed/AoA, become a real problem with this combination.

Handling a bogus stick shaker is probably an exercise that isn't trained enough anyway.
(Glad to be corrected on that)

Combine that with MCAS which can easily be construed as "handling difficulties" even if you could just use your trim switch to counteract the bogus trim.
(The noise and sensation of the stickshaker are probably the kicker, catching all focus and the trim wheel is ignored)

Personally i would like to see mandatory simulator training for a bogus stick shaker combined with a trim runaway.
Let's say 1 hour additional training for every pilot on type and when transitioning to type.
(Should probably mix in some genuine stick shaker events or that training might have a detrimental effect.)

Having an mandatory takeoff rejection at 80 kts if the AoA sensors disagree would also be prudent.
(Needs a new warning, but should be easy to implement in software)

On the MCAS thing i'm sure something is in the works
(limiting MCAS so it stops trimming when 20 pounds of stick force is reached might be a sufficient solution)

Last edited by wiedehopf; 11th Mar 2019 at 20:06.
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