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Old 12th Mar 2019, 10:10
  #635 (permalink)  
olster
 
Join Date: Dec 2006
Location: uk
Posts: 754
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Originally Posted by Interflug
Engineer here - trying to look at MCAS out of the box...

So they say, one AoA sensor outputting wrong data alone can activate the MCAS erroneously.
If that is so, which engineering workgroup at Boeing could in their sane minds design such a system, that is supposed to save you from a stall but instead:
-decisively flies you into the ground
-on a sunny cloudless day
-with a (except from the AoA sensor) perfectly functioning airplane and engines
-with the same system getting indications for:
positive vertical (upward) speed within normal margins
positive horizontal (forward) speed and acceleration within normal margins-secondary parameters like radar AGL data, GPS groundspeed-last but not least two pilots, able to look out of the window and able to assess AoA visually

Why would an engineer think it is a good idea to implement such a system that ignores all other available data (which indicates nothing like a stall)? Even if you want to take the pilot/human out of the equation, assuming he put the airplane into an attitude that will result in a stall, you still have lots of other available data the system can read, that tells it that you are in fact not stalling and that most likely the AoA sensor is telling you nonsense.

Probably the MCAS subsystem will enter the course books of engineering schools, as a textbook example of AS, artificial stupidity, a system designed to be stupid, when you actually need a smart system.

Or are these engineers disciples of the Church of the AoA sensor, since they believe the one and only AoA sensor never fails?

Someone can enlighten me? What did I overlook?
Yes Interflug, very difficult to disagree with you. Quite amazing, not in a good way. I have been flying the 737 off and on since the late 70s then the -200 through to latterly, the NG. I have continually said that the 737 is an old aircraft with bits bolted on over the decades. The ergonomics of the flightdeck are out of date for 2019 with the stab trim cut out switches hid away to the right of the start levers among many counter intuitive switches / system. I thought that the NG was a step too far, let alone the max. I am not going to join in the speculation but it does not look good. Tragic.
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