Boeing - Design Issues...

Discussion in 'Rules and Regulations / Flight Safety / Better Pil' started by TXFlyGuy, Apr 11, 2019.

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  1. Oct 24, 2019 #321

    davidb

    davidb

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    Restoring public confidence is certainly a hurdle given the misinformation and sensational reporting we’ve been subjected to. I heard the final report of one of these crashes was supposed to be presented to the surviving families today. Perhaps the general public will have access soon.

    I’m not entirely confident it will paint a clear picture as not all nations air their dirty laundry as we expect of the NTSB. We’ll see.

    Historically, AoA sensor malfunctions are not unheard of. One major airline sees on average two per year. Runaway stab trim enabled by faulty AoA was a new and bad thing. The system is now redesigned to mitigate the probability and severity. The same crew responses can no longer produce the same tragic outcome.

    I too would like to know the root cause of the AoA malfunction but I also know my safety and the safety of my passengers doesn’t rely on one or both AoAs.

    I would like to hear ideas about what it would take to earn your confidence of the Max. I’m sure thirty minutes in a simulator demonstrating normal and abnormal procedures would help. Would a video help?
     
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  2. Oct 24, 2019 #322

    davidb

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    I was thinking about that automobile commercial where the inattentive driver almost hits a pedestrian but the automatic braking system stops the car. If I have one of those cars and hit someone, is it the car/manufacturer’s fault?

    The car operators manual probably has a warning about not relying on the system and probably has a disabling switch should it start braking for flying insects. But, I guess it’s reasonable to ban all said cars from the streets rather than reminding one to adhere to the operators manual i.e., turn it off and drive.
     
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  3. Oct 24, 2019 #323

    AdrianS

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    As I understand it, the max as released should not have passed certification, since the amount of control authority the MCAS had (which was hidden from the FAA) meant that a single, standard AOA sensor was not acceptable.
     
  4. Oct 24, 2019 #324

    litespeed

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    Thats just facetious dribble.

    The Aircraft is banned worldwide from flying, the equivalant to a car been banned everywhere. This is only done if substantial evidence links a major safety problem that is deadly.

    Any comparison you make about driver or pilot responsibility is just bulldust to cover an inability to accept the grounding is warranted. All the evidence points this way but blaming a individual pilot or training of fleet, is just dishonest to the situation.
     
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  5. Oct 24, 2019 #325

    davidb

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    I think I misinterpreted your comment I quoted earlier and I’m sorry I led us down a path of silliness. I certainly agree the grounding is warranted. Honestly, I don’t think anyone disagrees. Even if there weren’t obvious design flaws, grounding would be prudent until a cause was apparent. The actions after the first crash weren’t sufficient to prevent the second crash. Hindsight indicates it should have never been certified. Nobody wants to chance blood of a third crash.

    The discussion has branches in several directions. Blaming is never productive and I hope any of my comments lead toward understanding and not taken as assessing blame. I do maintain crew training and experience is relevant but that doesn’t discount the design and engineering flaws.
     
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  6. Oct 24, 2019 #326

    litespeed

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    Thank you for clarifying.
     
  7. Oct 24, 2019 #327

    plncraze

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    The Langewische article linked through the Week's website dicusses airmanship and rote learning and functioning in the dynamic environment of an airplane's cockpit. The inter play between pilot and machine was interesting in these two crashes and when the plane talks you have to be ready to interpret what messages you receive.
     
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  8. Oct 24, 2019 #328

    BBerson

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    It's not just the Max but confidence in Boeing and automation.. I would remove the MCAS if possible. And change the name.
    I just watched the PBS Nova about self-driving cars last night. Vastly more difficult to engineer a self- driving car and they are going through the car and driver takeover control issues. It seems the self driving car is some years away.
    Boeing dove into this pilot/automation interface in a rush to certify with no experience.
    The whole issue of pilot-automation interface needs a hard look. It might be best to wait for the fully automated airplane instead of doing baby steps.
     
  9. Oct 24, 2019 #329

    Toobuilder

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    Anyone remember the Audi 5000 "unintended acceleration" crisis from the mid 1980's? The popular media (60 Minutes in particular) took the ball of hysteria and ran with it. What later turned out to be driver unfamiliarity and misaplication of controls essentially killed Audi in the US market overnight.

    Im not saying the MAX should not be grounded during the investigation period, but I DO think the airplane is "safe" in the hands of a properly trained crew. The airline industry has seen radical changes in technology and culture in it's relatively short history. We did things back in the day that, in retrospect, were completely wrong. We are compelled to learn and move forward. But the pilots have always been charged as the failsafe. That's why they get paid the "big bucks".

    The MAX has issues, no doubt. But I'm not about to let the pilots off the hook for their ultimate responsibility to PROPERLY manage an emergency.
     
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  10. Oct 24, 2019 #330

    davidb

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    I think you and I need to clarify what we mean when we say “automation” in regards to MCAS. In keeping with car analogies, are you somewhat familiar with electronic stability control and roll stability control common on new SUVs? I consider those things control and handling enhancements rather than automation. I reserve the term “automation” for features like auto parking or the car driving itself down the highway without driver input.

    Boeing was and is quite capable of engineering maneuver and control augmentation systems but for reasons not fully understood they really botched up an aspect with the Max. They now have fixed the issues with the MCAS that made it unsafe. They had the “know how” to do it right the first time. Why they didn’t do it right the first time will be scrutinized in the civil and criminal courts.
     
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  11. Oct 24, 2019 #331

    davidb

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  12. Oct 24, 2019 #332

    BBerson

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    Fixed what? A defective AOA sensor?
    The article above said the Indonesian investigators determined the second AOA was miscalibrated. What was wrong with the first one? What does Boeing say was at fault? Lots of questions remain.
     
  13. Oct 24, 2019 #333

    davidb

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    AoA sensors break for for various reasons. Two are installed. The plane can be safely recovered even if both were to break. I don’t know if the cause of failure will be determined. Sounds like the report will indicate improper maintenance actions after a bad one was written up. Single AoA failure should not have enabled MCAS trim. The fix is it now requires dual input. The other fix is MCAS trim is appropriately limited now.

    I’m certain the whole AoA system has gotten close scrutiny by the investigators and engineers. Lets see what the final report says. Sounds like the report will be out in a week or two.
     
  14. Oct 26, 2019 #334

    PagoBay

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    @Vigilant1
    You wrote -- What do you find deficient in the explanation of the crashes as provided by Langweishe?

    I posted this about three weeks ago. Would welcome your thoughts on this author's criticisms of the Langewiesche NY Times piece?
    =============
    The NY Times opinion piece by Wm. Langewiesche has come up several times now.
    Here is a very detailed commentary explaining where the opinion piece failed to address the case in a factually correct manner. An excellent article and a must read for those who are attending to this controversy. 14,000 Words Of "Blame The Pilots" That Whitewash Boeing Of 737 MAX Failure

    https://www.moonofalabama.org/2019/...that-whitewash-boeing-of-737-max-failure.html
    ============
    RMM - Guam
     
  15. Oct 26, 2019 #335

    davidb

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    The Final report is out. I’m having trouble posting a link.

    After reading through the transcript and data, it is doubtful this crew could have recovered the aircraft regardless of MCAS trimming. The bad AoA and the resulting bogus indications caused by that were overwhelming for this crew. Had they flown a known pitch and power setting and scanned all indications, they could have quickly determined all indications were normal on the right side.

    They simply didn’t know and didn’t do the immediate action memory items for airspeed unreliable. That’s a pretty serious training problem. Perhaps the stick shaker was an overwhelming factor that they just couldn’t ignore but at some point you have got to figure out takeoff power in level flight might actually give you 200+ knots above stall speed. It’s scary to think this might be an average crew at some airlines.

    edit: the comments above were based on my misinterpretation of the data. I’d like to retract some or all of this in a follow on post.
     
    Last edited: Oct 26, 2019
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  16. Oct 26, 2019 #336

    davidb

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    I just spent hours reading the report. I don’t feel well.
     
  17. Oct 26, 2019 #337

    davidb

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  18. Oct 26, 2019 #338

    Speedboat100

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    Crew ( both pilots ) had almost 10 000 hours flying time on 737s. Hardly an inexperienced crew.
     
  19. Oct 26, 2019 #339

    Vigilant1

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    The public discussion on this issue drives home the fact that many people don't understand what professional aircrews do, and what they are expected to do.
    Interviewer: The plane crashed because of a faulty AoA sensor (substitute "Airspeed sensor, etc as required)
    Pilot: Instruments occasionally fail, that's why critical ones have a backup. There are two independent AoA systems on the 737, at least one was right.
    Interviewer: But how could the pilots have known which was right?
    Pillot: Was the weather good? Was the artificial horizon operational? Pilots are trained to fly known pitch and power settings if they have reason to doubt their airspeed indications. There are two crewmembers on the flight deck so they can each handle part of the load of working these things out.
    Interviewer: But the stick shaker was going off, too. And speed alarms.
    Pilot: The crew is trained in how the systems in the airplane work. This knowledge allows them to determine the root cause when several related indications are faulty.
    Interviewer: Do you deny that the plane's design was defective?
    Pilot: I think we're seeing that both the plane's design and the training/certification of crewmembers can use improvement.
    Interviewer: Right. The plane was defective . . .
     
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  20. Oct 26, 2019 #340

    davidb

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    Agreed. That many hours represents many years and many recurrent training events. Both had less than 1000 hours total time in other aircraft.

    The cvr transcript during the preflight had the captain self proclaiming he was suffering from the flu. I don’t recall that being mentioned elsewhere in the report.
     

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