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Breaking news: Ethiopian Airlines flight has crashed on way to Nairobi

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  • Evan
    replied
    Originally posted by Gabriel View Post
    We are getting into semantics here, but it as a trim runaway, and not much different from other trim runaways. The trim runs like crazy in one direction you trim back with the thumb switch and the trim responds but then when you let go on the trim switch it starts trimming again on its own.
    No....

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  • 3WE
    replied
    Originally posted by Gabriel View Post
    ...as a trim runaway, and not much different from other trim runaways...
    Disconcur on “not much different”

    I think it was you that said “stall warning with pitch over” might have been the APPARENT MAJOR PROBLEM, with Boeing sharing near ZERO information to pilots on this INSIDIOUS, poorly redundant, and easily mechanically binding system.

    With ‘traditional’ trim runaways the distractions that you are stalling and have several OTHER problems are absent and the big wheel is much more obvious. I know you don’t think stall management is important...

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  • Gabriel
    replied
    Originally posted by Evan View Post
    The pilots cannot be expected to handle a situation until they can understand it. The aircraft was not behaving in the same manner as a trim runaway. Because it wasn't a trim runaway.
    We are getting into semantics here, but it as a trim runaway, and not much different from other trim runaways. The trim runs like crazy in one direction you trim back with the thumb switch and the trim responds but then when you let go on the trim switch it starts trimming again on its own.

    Leave a comment:


  • Gabriel
    replied
    Originally posted by elaw View Post
    Okay I'm a little slow and realized your light bulb analogy was probably meant in the "Swiss cheese" sense, that if any one factor were not present the accident would not happen.

    But I think that analogy is kind of like saying that in a bank robbery, the bank and the robber are both 100% at fault because if neither was present, the robbery would not have happened. If you go out and survey 100 people on the street, I doubt you're going to find one that feels the bank was 100% at fault. You might find a few that think it was 10% at fault because it had a poorly-maintained security system or something like that, and I think that kind of reasoning has value because it allows you to compare the magnitude of each factor and respond appropriately.

    Take my UA232 example... IMHO saying the engine failure and the pilots are both 100% responsible for the deaths that occurred is absurd. The engine failure clearly was the proximate cause of the crash, a lot of resources were dedicated to diagnosing that problem and preventing it from recurring, and IMHO a lot of benefit was derived from that. Putting an equal amount of resources into trying to train every pilot to perform as well as or better than Al Haynes and company would be a fool's errand. Mostly in the sense that trying to teach them to fly an aircraft severely damaged in a very edge-case way would divert resources from training them to deal with much more likely scenarios. Trim runaway, for example.
    Ok, but it's not the same in this case. Here Boeing, the FAA, the pilots, the airlines and the local authorities ALL screwed up big time and their screw-up (not their mere existence) was NECESSARY for these accidents to happen. In the UA232 case, the pilots did not screw up, in fact their action was key in the outcome of having survivors (and a lot of them) in what, under normal circumstances, should have been a crater in the ground with no recognizable body remains. But in the MAX accidents, the system should not have been so fault-intolerant and the fault, once it happened, should not have been much more than an annoyance.

    Note that I said blame (or you can say responsibility or accountability), you don't have any less when you share some.
    But liability can be shared and split.

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  • Evan
    replied
    Originally posted by elaw View Post
    You say the pilots were put into a disorienting situation (yes I know there were other words but bear with me). Flying into a cloud is disorienting... many many accidents over the years have proved that. Yet competent instrument-rated pilots can handle flying into clouds without crashing... millions of successful flights over the years have proven that. Competency is a thing, and can affect the outcome of many situations, especially in aviation. And to quote a wise ex-coworker of mine, "competency varies".
    Indeed it does, which is why it can't be the sole redundancy for a single point failure of a system that interferes with flight control. And flying into a cloud is not disorienting in the way that having the plane robotically fight you is.

    A "typical emergency"... what exactly is that?
    One that isn't unheard of, trim runaway for instance.

    You mention another trim runaway incident that ended up with dead aviators, presumably to prove the point that runaway trim kills people.
    No, I provided that as an example of how a manageable emergency can become a fatal one if the crew is overwhelmed and distracted with systems issues.

    The bottom line is I am not going to say the aircraft is 100% to blame in an emergency situation the pilots were trained to handle.
    The pilots cannot be expected to handle a situation until they can understand it. The aircraft was not behaving in the same manner as a trim runaway. Because it wasn't a trim runaway.

    The bottom line is this: despite the legions of shoddy airman flying 737NG's over two decades, none has ever crashed from a trim runaway, and they do happen. Yet, in the first year of service, two B737-MAX's crashed from an MCAS runaway. The airplane design is to blame for that.

    100%

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  • elaw
    replied
    Okay I'm a little slow and realized your light bulb analogy was probably meant in the "Swiss cheese" sense, that if any one factor were not present the accident would not happen.

    But I think that analogy is kind of like saying that in a bank robbery, the bank and the robber are both 100% at fault because if neither was present, the robbery would not have happened. If you go out and survey 100 people on the street, I doubt you're going to find one that feels the bank was 100% at fault. You might find a few that think it was 10% at fault because it had a poorly-maintained security system or something like that, and I think that kind of reasoning has value because it allows you to compare the magnitude of each factor and respond appropriately.

    Take my UA232 example... IMHO saying the engine failure and the pilots are both 100% responsible for the deaths that occurred is absurd. The engine failure clearly was the proximate cause of the crash, a lot of resources were dedicated to diagnosing that problem and preventing it from recurring, and IMHO a lot of benefit was derived from that. Putting an equal amount of resources into trying to train every pilot to perform as well as or better than Al Haynes and company would be a fool's errand. Mostly in the sense that trying to teach them to fly an aircraft severely damaged in a very edge-case way would divert resources from training them to deal with much more likely scenarios. Trim runaway, for example.

    Leave a comment:


  • elaw
    replied
    Originally posted by Gabriel View Post
    It's like having 6 bulbs in a serial connection saying that you have 1 amp flowing through the circuit and asking "ok but what fraction of the 1 amp does each bulb take?"
    Or... is it like having 6 bulbs in a parallel connection saying that you have 1 amp flowing through the circuit and asking "ok but what fraction of the 1 amp does each bulb take?"

    Oh and two of the bulbs are not lit because someone pulled the circuit breaker.

    Leave a comment:


  • Gabriel
    replied
    Originally posted by elaw View Post
    Are you one of those people that asks for a pizza to be cut into 6 slices because you can't eat 8?
    No, because you do eat less pizza if you share some.

    It's like having 6 bulbs in a serial connection saying that you have 1 amp flowing through the circuit and asking "ok but what fraction of the 1 amp does each bulb take?"

    Leave a comment:


  • elaw
    replied
    Are you one of those people that asks for a pizza to be cut into 6 slices because you can't eat 8?

    Leave a comment:


  • Gabriel
    replied
    I disagree with both of you. Boeing has 100% of the blame. The FAA has 100 of the blame. The pilots have 100% of the blame. The airlines have 100% of the blame. And the local regulatory agencies have 100% of the blame. It took all of them to screw up for these accidents to happen. Blame is one of the things (together with love and knowledge) that you don't lose a bit when you share some.

    Leave a comment:


  • elaw
    replied
    Well I'm going to have to disagree with your disagreement. I don't always agree with the criticism you get here re "black-and-white reasoning" but in this case I concur with it.

    Where to start... how about at the beginning?

    You say the pilots were put into a disorienting situation (yes I know there were other words but bear with me). Flying into a cloud is disorienting... many many accidents over the years have proved that. Yet competent instrument-rated pilots can handle flying into clouds without crashing... millions of successful flights over the years have proven that. Competency is a thing, and can affect the outcome of many situations, especially in aviation. And to quote a wise ex-coworker of mine, "competency varies".

    A "typical emergency"... what exactly is that? You mention another trim runaway incident that ended up with dead aviators, presumably to prove the point that runaway trim kills people. However there are many documented cases of trim runaways being successfully dealt with by pilots, and numerous people failing to die as a result. Does this sound a little like the cloud situation I describe above? Competent pilots usually handle encounters with clouds successfully, non-competent pilots and non-pilots generally don't. Competent pilots have handled trim runaways successfully, non-competent pilots (and some who were probably just having a bad day) have not.

    Let me give a few more illustrating examples. Suppose you're piloting a DC-10 and a compressor disk explodes in the #2 engine, taking out all the hydraulics. A pretty clear-cut case of a plane trying to kill its inhabitants, yet in UA232 many survived due to the exceptional piloting and teamwork of a few individuals. On the other hand there are a lot of recorded cases of airplanes doing absolutely nothing wrong, and damage to aircraft/property/persons taking place due to the actions of incompetent/complacent/half-asleep/etc. pilots... landing with the gear up, landing long and running off the end of the runway, flying into weather the aircraft can't handle (or flying improperly even when the plane *can* handle the weather, resulting in a crash), etc. etc. Once again, competency affects the outcome.

    The bottom line is I am not going to say the aircraft is 100% to blame in an emergency situation the pilots were trained to handle. If the aircraft lends some nuance to the situation that the pilots were not trained for, sure that's the aircraft's fault. And yes if the aircraft fails at all in any way that contributes to the accident, it's partly at fault. But cases like this are why the NTSB and others say those factors contribute to the accident (blame on aircraft < 100%) rather than causing the accident (blame on aircraft = 100%).

    Leave a comment:


  • Evan
    replied
    Originally posted by elaw View Post
    However the fact Boeing is trying to deflect blame does not mean they were 100% to blame for what happened.
    I have to disagree. Boeing put these pilots into a very disorienting, difficult to diagnose (if not impossible to diagnose, if they weren't even aware of MCAS) situation. That changes everything. They can't then suggest that the crew should have been able to treat it as a typical emergency. HIghly trained and proficient crews might have managed it. Less proficient crews might not have. Are there less proficient crews up there? Oh yes. Especially at airlines with a worrisome record for these things, like the ones to which Boeing agressively marketed the 737-MAX. It's a bit hypocritical to sell these airlines an airplane that depends so heavily on flawless pilot performance under the most confusing and stressful circumstances, and then try to shift the blame there in the aftermath.

    The Ethiopian crew left the thrust in TOGA the entire time. Obviously, they were distracted from flying the plane due to the situation they were trying to understand. Boeing did that.

    This is interesting and prophetic: An article titled Pitch Trim Runaway Right after takeoff, it’s a recipe for disaster, from 2017. Prior to either crash, there was a Cessna Citation being flown by a very experienced ATPL pilot that crashed into Lake MIchigan. The NTSB believe it was the result of a trim runaway. The plane should have been controllable, but the crew let the speed get too high while being distracted with troubleshooting. Sound familiar?

    The NTSB cited the crew’s “haphazard and poorly coordinated troubleshooting efforts” as having “allowed an abnormal situation to escalate to an emergency” and concluded that “if the pilots had simply maintained a reduced airspeed ... the aerodynamic forces on the airplane would not have increased significantly” and “the pilots should have been able to maintain control of the airplane.”
    https://www.aopa.org/news-and-media/...h-trim-runaway

    Leave a comment:


  • elaw
    replied
    Well of course they're trying to deflect blame! The first reaction of any corporation when caught with their hands in a cookie jar is to claim their hands were not in the cookie jar, and also that they don't have hands and that cookie jars don't actually exist but if they did it would greatly benefit society if all corporations had their hands in cookie jars.

    However the fact Boeing is trying to deflect blame does not mean they were 100% to blame for what happened. Don't get me wrong, I'm not trying to claim they were 0% to blame either (though the tone of some of my earlier posts may have sounded that way).

    My feeling is that any professional pilot should be prepared to deal with a trim runaway when flying a plane that can experience that, which is almost all non-FBW airliners. But... Boeing put pilots in a plane that had an additional failure mode not found in many airliners (including earlier 737s) that could cause trim runaway, and would do it in a confusing fashion - meaning that when the pilots did certain things, the runaway would stop, only to resume moments later.

    So IMHO Boeing and the pilots each deserve some of the blame.

    Leave a comment:


  • Evan
    replied
    Originally posted by Gabriel View Post
    Not sure if I wasn't clear. The design of the MCAS was a disaster. The design needs to be fixed and Boeing and the FAA need to be fixed. No dispute on that.

    Now, with these pilots behind the wheel, do you feel more comfortable flying a 737 NG than a MAX? Because I don't think we would survive a runaway trim of the NG flavor either (no MCAS involved).
    (acknowledged, the MCAS adds another failure mode for the trim runaway to happen, and one of unacceptable probability of occurrence, but trim runaways do happen for other reasons too)

    Boeing needs to be fixed. But it is not the only thing that needs to be fixed.
    Of course, I agree completely. My concern is that Boeing (through their media minions) is trying to deflect some of the blame. Yes, the crash couldn't have happened without pilot error, but the confusing scenario they created is highly conducive to pilot error. Pilot's don't just commit errors because they are bad or poorly trained pilots. They also commit errors because they lose their grasp of very stressful situations.

    I think there is reason to think that these pilots would handle a conventional trim runaway correctly. I agree that they needed better training.

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  • Gabriel
    replied
    Originally posted by Evan View Post
    It takes an incendiary environment to make a fire. Boeing engineered an incendiary environment. That can never be tolerated because the ignition source is human nature.
    Not sure if I wasn't clear. The design of the MCAS was a disaster. The design needs to be fixed and Boeing and the FAA need to be fixed. No dispute on that.

    Now, with these pilots behind the wheel, do you feel more comfortable flying a 737 NG than a MAX? Because I don't think we would survive a runaway trim of the NG flavor either (no MCAS involved).
    (acknowledged, the MCAS adds another failure mode for the trim runaway to happen, and one of unacceptable probability of occurrence, but trim runaways do happen for other reasons too)

    Boeing needs to be fixed. But it is not the only thing that needs to be fixed.

    Leave a comment:

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