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Lion Air 737-Max missing, presumed down in the sea near CGK (Jakarta)

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  • BoeingBobby
    replied
    Originally posted by Gabriel View Post
    They were all the time in manual flight, bit AT and AP were off. But that doesn't prevent the MCAS for automatically applying nose-down trim if it thinks it's about to stall, what it did since one of the 2 AoA sensors was showing a wrong too high AoA.
    So you reach down and turn the Stab Trim Cutout Switches to the OFF Position! Now you can fly it like a Cub!

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  • Gabriel
    replied
    Originally posted by ATLcrew View Post
    There are people who would do just that.
    Yes, and they should be kept away from cockpits.

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  • Gabriel
    replied
    Originally posted by TeeVee View Post
    this may very well turn out to be the most damning piece of "evidence" against boeing.

    i am going to predict that boeing is going to settle with the plaintiffs in the case(s) filed against it related to this tragedy and while evan an others will cry about opportunistic lawyers, the families deserve some form of compensation as a result of the loss of breadwinners.

    i personally would love to see REAL criminal prosecution against those at boeing that deemed it more financially expedient to essentially hide this new (redesigned and substantially modified) system.
    This is going to be a cornerstone in the aviation industry. Plane makers consistently not disclose (which is not the same as hide) details of how the plane works.
    If Boeing is severely hit because of this incident, and in particular if there is a criminal prosecution, the they would go lawyer mode and put in the manuals EVERY detail of the plane and systems design, down to flowcharts and line codes. It will be so much information that it will be impossible for pilots to learn and retain everything. And then the plane makers will just blame the pilot (because we clearly stated in the manuals that if sensor B-47 in the computer RJT62 gave a false signal combined with the flight-sub-mode being on alternate 34 then there wold be an input of 2.45mV in the left side of the green control system that would make trim add incremental nose-down inputs and the recovery procedure for that is to move the trim cutout switches to cutout", instead of just saying "in case of trim runway (which by the way can happen in a number of different scenarios and for a number of different reasons), move the trim cutout switches to cutout. Which one do you think is safer?

    As automation increases, systems become intrinsically more complex and interface with the human is supposed to become simpler. It is that interface, and not the deep levels of details, which needs to be very clear.

    The procedure for trim runaway was there in the plane's operation and training manuals, and also in the QRH, and it is a memory item. And as I explained, they also had alternate reasonable, intuitive ways not to crash following just common pilot practices that apply to a Piper Cub too. According to Boeing (we still need to see how true this is), the existence and general explanation of this new system was also in the plane's manual, although apparently there was no great details nor specific procedures for its operation (which were not needed, since the general "trim runaway procedure for any reason" would apply.

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  • ATLcrew
    replied
    Originally posted by Gabriel View Post
    Once again, I disagree. Or more precisely, I agree with what you say but it is not enough to explain what happened.
    Say that in the office where you work one day they build a new wall in a place you usually walked through. Would you just walk into the wall that is there in plain sight, and that you do see it, and then blame that there was no memo informing of the new wall and that you were not properly trained in wall avoidance?
    There are people who would do just that.

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  • Gabriel
    replied
    Originally posted by Evan View Post
    That seems to have been the problem. The system that was fighting them is probably only engaged in manual flight. I have to believe autopilot was not available with an AoA disagree.

    Apparently, this wasn't a complacency thing. It was a lack of training on abnormal operations and a lack of awareness about a crucial new system.

    That and the distraction, stress and disorientation these situations breed. I think these guys just finally succumbed to battle fatigue.

    You, of course, would have handled it just fine, but how did you learn how to do that? Were you trained on this or did it just come to you in a dream?

    We cant expect pilots to fly the f******g airplane if we haven't taught them how the f******g airplane works,
    Once again, I disagree. Or more precisely, I agree with what you say but it is not enough to explain what happened.
    Say that in the office where you work one day they build a new wall in a place you usually walked through. Would you just walk into the wall that is there in plain sight, and that you do see it, and then blame that there was no memo informing of the new wall and that you were not properly trained in wall avoidance?

    These guys were successfully fighting the automatic periodic nose-down trim inputs (that unknown to them were being made by the MCAS, of which they were not aware of its existence) with manual nose-up trim inputs using the yoke switch, managing to keep the plane reasonably in level light. They stop fighting back and the plane starts to dive what they initially compensate by pulling down on the yoke harder and harder, until they are overwhelmed. They end up letting the nose of the plane nose down, the plane dive, and crash, with them pulling back on the yoke as hard as they could, and not trying to trim up? Again, yes, using the proper trim runaway procedure would have saved the day (as it probably did in the previous flight). Knowing about the MCAS may have helped too (unless pilots in daring and confusing situations are known to misidentify the system behavior at play even if they are aware of its existence and function). But these 2 alone doesn't explain what the crew did and in particular what they did not do.

    I tend to agree with 3we about confusion. Perhaps the stick-shaker shaking all the time made them think that they were actually near stall (the high airspeed on both sides even with the speed disagree combined with a low deck angle and a stable altitude should have been a clear cue in contrary, but...) and they decided that repeated trim-up inputs would make things worse and they committed to let the nose go down to "recover" from the stall and when the nose did go down and pulling up didn't fix it they thought that they were still in a stall and decided to not to make more nose-up trim inputs (but then why they kept pulling up as hard as they could?)

    Again, I suspect confusion was key in the final loss of control, but I don't understand what kind of confusion would lead to the combination of actions taken (other than no particular confusion other than total continued startle, but even then if something was working let's say not so badly and you change the strategy to try to improve it and things go way wrong, returning to the previous strategy would be wise). Depending on what the CVR tells (if found), we may or may not ever know.

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  • Gabriel
    replied
    Originally posted by BoeingBobby View Post
    Click click, click click, hand full of yoke, hand full of thrust levers, fly the f*****g airplane!
    They were all the time in manual flight, but AT and AP were off. But that doesn't prevent the MCAS from automatically applying nose-down trim if it thinks it's about to stall, what it did since one of the 2 AoA sensors was showing a wrong too high AoA.

    Leave a comment:


  • brianw999
    replied
    A couple of interesting links....

    https://mothership.sg/2018/11/lion-a...erwork-causes/

    http://www.lionair.co.id/lion-experience/facilities

    One thing is for sure, Lion Air is on my “no fly” list.

    Leave a comment:


  • BoeingBobby
    replied
    Originally posted by Evan View Post
    There are! The billion-dollar question is: why weren't they used. The billion-dollar answer might be because the billion-dollar company didn't do much to train their pilots on this. Or it might be some other thing that I can't possibly imagine...
    Not sure where their pilots are doing training. I seriously doubt they have their own simulators. Like Gabriel said a few posts ago, runaway trim is something that has been trained since electric trim was first installed. My opinion is another case of children of the magenta line.

    Leave a comment:


  • brianw999
    replied
    The base cause of this crash comes down to a simple fact. Two people in the absolute front seats of the aircraft failed to perform to their job description....that is, BE A PILOT ! They stayed in the realms of being a computer operator and they and their passengers died because of it. When you are in an aircraft that is on autopilot then you cease to be “A Pilot” and instead become a computerised activity monitor. When the computers stop doing their job then the Pilot needs to manually take control, do his/her job and FLY the bloody thing.

    Leave a comment:


  • Evan
    replied
    Originally posted by TeeVee View Post
    while evan an others will cry about opportunistic lawyers...
    Not in this case. Bring on the opportunistic lawyers, by all means.

    Leave a comment:


  • Evan
    replied
    Originally posted by BoeingBobby View Post
    I have no experience in any of the 73's, but I have to assume that there are stab trim shut off switches on the pedestal like every other Boeing product that I have flown since the 707.
    There are! The billion-dollar question is: why weren't they used. The billion-dollar answer might be because the billion-dollar company didn't do much to train their pilots on this. Or it might be some other thing that I can't possibly imagine...

    Leave a comment:


  • BoeingBobby
    replied
    I have no experience in any of the 73's, but I have to assume that there are stab trim shut off switches on the pedestal like every other Boeing product that I have flown since the 707.

    Leave a comment:


  • ATLcrew
    replied
    Originally posted by TeeVee View Post
    i am going to predict that boeing is going to settle with the plaintiffs in the case(s) filed against it related to this tragedy and while evan an others will cry about opportunistic lawyers, the families deserve some form of compensation as a result of the loss of breadwinners.
    You mean like in most other product liability cases?

    Leave a comment:


  • elaw
    replied
    Originally posted by Evan View Post
    ...lack of awareness about a crucial new system.
    While I'm not going to say the new system was no factor, IMHO it is a minor factor.

    Trim runaways have been a thing since electric motors were first connected to trim systems in the 1930s. It's an issue any pilot of a complex aircraft should be prepared to deal with.

    Leave a comment:


  • TeeVee
    replied
    Originally posted by Evan View Post
    We cant expect pilots to fly the f******g airplane if we haven't taught them how the f******g airplane works,
    this may very well turn out to be the most damning piece of "evidence" against boeing.

    i am going to predict that boeing is going to settle with the plaintiffs in the case(s) filed against it related to this tragedy and while evan an others will cry about opportunistic lawyers, the families deserve some form of compensation as a result of the loss of breadwinners.

    i personally would love to see REAL criminal prosecution against those at boeing that deemed it more financially expedient to essentially hide this new (redesigned and substantially modified) system.

    Leave a comment:

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