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Old 20th Apr 2019, 23:43
  #4182 (permalink)  
Dani
 
Join Date: Aug 2002
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Originally Posted by 737 Driver
At Ethiopian, the DFDR data suggests that the AOA was working during the takeoff run, but was disabled shortly after liftoff, possibly by a bird strike.
Thanks for taking your time taking me with you on the matter.
Still, who tells us that it was a bird strike? It could be very well that the flight computer software delivers correct AOA data to the stall computer on ground and then starts to mix them up in the air. I read nothing of a bird strike in the preliminary.

Avherald says:
A false AoA value, probably produced by the Air Data Reference unit rather than a mechanical fault, which activated the stick shaker and MCAS.
This does not mean that the AOA is broken, but the AOA data.

That's why it is not wise to critisize the MCAS (alone), but the data handling of the whole system. I think Boeing and FAA know very well that it's not an isolated MCAS problem, but a flight control computer software problem on a wider scale.

Dani
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