PPRuNe Forums - View Single Post - Ethiopian airliner down in Africa
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Old 2nd Apr 2019, 19:58
  #2920 (permalink)  
gums
 
Join Date: Jun 2009
Location: florida
Age: 81
Posts: 1,610
Received 55 Likes on 16 Posts
Salute Ferry !!
I love it.

Although I flew very sophisticated aerospace vehicles, I am not quite ready to let HAL run everything at this time. And you are correct about not providing the human crewmembers with realistic training and practice for that one day they may have to actually perform their 'Chuck Yeager" routine. The "children of the magenta line" still live, and there's more of them every year.
CASE IN POINT:
The Lion 610 and previous flight's MCAS problem would not have been handled successfully by HAL, especially if the same sfwe shop did the design and code. At the time of Lion 610, the problem facing the plane was not the basic "runaway trim" that most of us think about. Then there;s the stall warning! HAL would likely have commanded some nose down, huh? Did HAL know altitude above the terrain or note the rising terrain ahead? Did the sfwe folks think that MCAS would activate at takeoff speed, and a few hundred feet and not at the other end of the envelope doing a banked turn at 20,000 feet? Would HAL have reduced power at 700 feet with stall warning shaking and been aware that getting too fast would reduce elevator effectiveness due to "blow up" with AND trim being commanded?

The single point of failure, the AoA doofer, that everyone points out was only the first event in the sequence that eventually resulted in loss of control. Just like almost all crashes. Few are the result of one thing going tango uniform. And that is where HAL has trouble, but the carbon-based lifeforrms can connect things that HAL's father had not thot of, and then do something not "programmed". You know, turn off both electric stab switches before treating the stall warning and not experiencing continuous trim in one direction.

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