4 ms·

I don't think you have. Bright's arguments have focused entirely on the design of the MCAS software, and have as far as I can tell completely ignored the fact t

I don't think you have. Bright's arguments have focused entirely on the design of the MCAS software, and have as far as I can tell completely ignored the fact that that software, driven by input from a single AoA sensor, creates a very short critical failure path which requires immediate and precise human intervention to avert a fatal accident. That such human intervention was imperfectly performed in two cases does not indict the humans in question, so much as it indicts a design which errs so far on the side of unsafety that perfection in human behavior is required to prevent it killing everyone on board a commercial aircraft. Any competent engineer knows that a design which requires human perfection for safety is a design not only doomed to failure, but a failed design in itself. At least one Boeing engineer raised this very concern during the 737 MAX design process, only to be quashed by management. It would be invidious to suggest that at least one ex-Boeing engineer should argue in the defense of that design out of any motivation other than a genuine conviction of the merit in his argument. But conviction alone doesn't suffice to render that argument meritorious, and I'm surprised and disappointed to see anyone here or elsewhere claim otherwise.

lisper 7y ago
Thanks, but I really would like to hear what supportlocal4h has to say about it. You're just repeating the party line. (And just for the record, I agree with the party line. But I think it's important to listen to and understand dissenting views.)
- o-__-o 7y ago
  Everybody is at fault. Pilots for not flipping the switch. Foreign aviation regulations for not requiring more knowledge (hours) in the cockpit. Airlines for not buying safety equipment. Boeing for not making safety equipment standard and then playing the cover-up/shift-blame game. You all can debate who is responsible for what %, but I’m not a judge nor a jury so I won’t speculate. But facts is facts, and everyone in the chain above deserves blame
- supportlocal4h 7y ago
  This it's how I read it: 1. Boeing is not blameless. 2. Boeing has a point about MCAS issues manifesting exactly like another well-known event in other models and having the exact same solution. 3. The well-known solution to the well-known event is one that pilots must memorize because they don't have time to look it up. 4. The pilots seem to have demonstrated that they recognized the problem and, in fact, executed the well-known solution in time. They just failed to complete all the steps for some unknown reason. 5. Points 2-4 don't mean that Boeing is perfect. MCAS needs to be fixed. But it isn't completely absurd to argue that MCAS really is so similar in its misbehavior and so identical in the correct response that a reasonable person might expect pilots to do the right thing even if they had never heard of MCAS. Taken together, this paints a picture to me that is different than the completely evil, conniving picture I had. I'm not sure where to draw the line between them, but probably not on the extreme end where I had it. But my point is not so much about Boeing. I was observing the actions of a person who took what I expect to be a very unpopular stand in the face of overwhelming popular opinion. For what? Who cares if somebody else is mischaracterized? There's nothing you can do about it except get yourself muddy. Just let it happen and keep your head down. I don't know why Walter is speaking up now. I'm not sure how much it changes my opinion. But I still tip my hat to a person who will say what they think is right even when they know they will be burned at the stake for it.
  - lisper 7y ago
    Thanks for the response. Two follow-up questions: > MCAS issues manifesting exactly like another well-known event in other models and having the exact same solution By "another well-known event" do you mean a runaway trim? Because if you do, then you're mistaken. MCAS and runaway trim differ in significant ways. And if you don't, what do you mean? > I don't know why Walter is speaking up now. Have you considered the possibility that he's a shill?
    - jacobush 7y ago
      It sounds so crude... I prefer “biased”. It’s our Walt...
    - WalterBright 7y ago
WalterBright 7y ago
I did not defend Boeing's MCAS design.
briandear 7y ago
> have as far as I can tell completely ignored the fact that that software, driven by input from a single AoA sensor, creates a very short critical failure path which requires immediate and precise human intervention to avert a fatal accident. Not too precise. Lowering flaps or not raising them in the first place solves it since flaps disengage MCAS. And on the Lion Air flight, the AOA sensor was already squawked prior to the flight but the incompetent Lion Air maintenance process ignored it despite that sensor being on the MEL for that airplane. Lion Air allowed a legally un-airworthy aircraft to depart. Boeing owns some of the blame, but the pilot-factories of third world airlines deserve a lot of the blame as well. In Lion Air’s case, their maintenance failures deserve 100% of the blame because they allowed a plane to take off with a system required for airworthiness to not be fixed. If a plane requires a widget to be legally airworthy and maintenance and the pilot in command knowingly allowed the plane in the air without that functioning widget, anything that happens as a result afterwards is the fault of the maintenance and pilot in command. That the widget was required; that’s on Boeing. That the widget failed, that’s also on Boeing; that the plane was allowed to fly by that airline — that’s on the airline.
- pdonis 7y ago
  > Lowering flaps or not raising them in the first place solves it since flaps disengage MCAS. But the pilots weren't told that and didn't know it. Nobody was trained or informed that "lower flaps" was a proper response to "trim system malfunction", and I don't see why it would be an obvious thing to come up with on your own. > they allowed a plane to take off with a system required for airworthiness to not be fixed Did Lion Air know the AoA sensor was required for airworthiness? Nobody outside Boeing knew MCAS existed at the time.

lisper 7y ago

Thanks, but I really would like to hear what supportlocal4h has to say about it. You're just repeating the party line. (And just for the record, I agree with the party line. But I think it's important to listen to and understand dissenting views.)

o-__-o 7y ago
Everybody is at fault. Pilots for not flipping the switch. Foreign aviation regulations for not requiring more knowledge (hours) in the cockpit. Airlines for not buying safety equipment. Boeing for not making safety equipment standard and then playing the cover-up/shift-blame game. You all can debate who is responsible for what %, but I’m not a judge nor a jury so I won’t speculate. But facts is facts, and everyone in the chain above deserves blame
supportlocal4h 7y ago
This it's how I read it: 1. Boeing is not blameless. 2. Boeing has a point about MCAS issues manifesting exactly like another well-known event in other models and having the exact same solution. 3. The well-known solution to the well-known event is one that pilots must memorize because they don't have time to look it up. 4. The pilots seem to have demonstrated that they recognized the problem and, in fact, executed the well-known solution in time. They just failed to complete all the steps for some unknown reason. 5. Points 2-4 don't mean that Boeing is perfect. MCAS needs to be fixed. But it isn't completely absurd to argue that MCAS really is so similar in its misbehavior and so identical in the correct response that a reasonable person might expect pilots to do the right thing even if they had never heard of MCAS. Taken together, this paints a picture to me that is different than the completely evil, conniving picture I had. I'm not sure where to draw the line between them, but probably not on the extreme end where I had it. But my point is not so much about Boeing. I was observing the actions of a person who took what I expect to be a very unpopular stand in the face of overwhelming popular opinion. For what? Who cares if somebody else is mischaracterized? There's nothing you can do about it except get yourself muddy. Just let it happen and keep your head down. I don't know why Walter is speaking up now. I'm not sure how much it changes my opinion. But I still tip my hat to a person who will say what they think is right even when they know they will be burned at the stake for it.
- lisper 7y ago
  Thanks for the response. Two follow-up questions: > MCAS issues manifesting exactly like another well-known event in other models and having the exact same solution By "another well-known event" do you mean a runaway trim? Because if you do, then you're mistaken. MCAS and runaway trim differ in significant ways. And if you don't, what do you mean? > I don't know why Walter is speaking up now. Have you considered the possibility that he's a shill?
  - jacobush 7y ago
    It sounds so crude... I prefer “biased”. It’s our Walt...
  - WalterBright 7y ago

WalterBright 7y ago

I did not defend Boeing's MCAS design.

briandear 7y ago

> have as far as I can tell completely ignored the fact that that software, driven by input from a single AoA sensor, creates a very short critical failure path which requires immediate and precise human intervention to avert a fatal accident. Not too precise. Lowering flaps or not raising them in the first place solves it since flaps disengage MCAS. And on the Lion Air flight, the AOA sensor was already squawked prior to the flight but the incompetent Lion Air maintenance process ignored it despite that sensor being on the MEL for that airplane. Lion Air allowed a legally un-airworthy aircraft to depart. Boeing owns some of the blame, but the pilot-factories of third world airlines deserve a lot of the blame as well. In Lion Air’s case, their maintenance failures deserve 100% of the blame because they allowed a plane to take off with a system required for airworthiness to not be fixed. If a plane requires a widget to be legally airworthy and maintenance and the pilot in command knowingly allowed the plane in the air without that functioning widget, anything that happens as a result afterwards is the fault of the maintenance and pilot in command. That the widget was required; that’s on Boeing. That the widget failed, that’s also on Boeing; that the plane was allowed to fly by that airline — that’s on the airline.

pdonis 7y ago
> Lowering flaps or not raising them in the first place solves it since flaps disengage MCAS. But the pilots weren't told that and didn't know it. Nobody was trained or informed that "lower flaps" was a proper response to "trim system malfunction", and I don't see why it would be an obvious thing to come up with on your own. > they allowed a plane to take off with a system required for airworthiness to not be fixed Did Lion Air know the AoA sensor was required for airworthiness? Nobody outside Boeing knew MCAS existed at the time.