Boing 737 Max-8 crashes

Discussion in 'Off-topic' started by gunsmoker, Mar 15, 2019.

  1. gunsmoker

    gunsmoker Lawyer and Gun Activist

    27,542
    684
    113
    https://www.google.com/url?sa=i&source=web&cd=&ved=2ahUKEwj027zOy4XhAhUHEawKHVCNDMoQzPwBegQIARAC&url=https://www.nytimes.com/2019/03/15/business/boeing-ethiopian-crash.html&psig=AOvVaw3Erl7Ezfc8mJREbz3qRh_m&ust=1552788914351914


    So earlier today I was speaking to 2 people--an aeronautical engineer who works for a defense contractor on jet aircraft, and a computer science engineer with a degree from Georgia Tech. Both of them are private pilots although one of them only works professionally in the aerospace industry.

    I asked them about these two crashes involving the Boeing 737 max-8. They theorized that the airplanes' automatic pilot system caused it. These systems now appearing in passenger jets incorporate a computer override that will prevent the pilot from assuming manual control if the computer decides that the pilots movements (stick, rudder, throttle, etc.) are inconsistent with the safe operation of the airplane.

    In other words, the primary flight responsibility is the computer (auto pilot) but when everything is going well the human pilot has the option of disengaging the auto pilot and flying the plane manually (although it is still fly by wire, with all the control levers & buttons connected to a circuit board which treats them as requests, and only if the computer approves the request will pistons actuate and servos move, which causes the airplane to actually turn or otherwise change what it's doing.)

    But if the computer thinks that the airplane is climbing too steeply, it will automatically increase the throttle (to prevent a stall) and push the nose down in an attempt to come back to level flight. If the sensors were in error and the computer is working on false data, this will cause the aircraft to fly at full throttle straight down into the ground and make a big smoking hole. While the pilots will see this coming and might realize what's about to happen, there's not a got-damned thing they can do about it.
    Because the computer has priority over the human pilots now.
     
    Last edited: Mar 15, 2019
  2. Phil1979

    Phil1979 Member Georgia Carry

    11,494
    601
    113
    Wow, that's really bad. The pilots should have final authority over their aircraft.
     

  3. Nemo

    Nemo Man of Myth and Legend

    12,824
    830
    113
    Trying to make planes like they want the world. Object/govt controls all, persons only control when govt permits.

    Nemo
     
  4. Phil1979

    Phil1979 Member Georgia Carry

    11,494
    601
    113
    I seem to recall an incident, perhaps a small Russian airliner, where they lost most or all of their hydraulics. Physically putting muscle into the yoke, they were able to safely land.

    First there was fly-by-wire, then there was wire takes control. The concept of slippery slope proved right there.
     
  5. moe mensale

    moe mensale Well-Known Member

    12,631
    1,711
    113
    I call bullshit. AI is the future. That's why the feds are pushing for autonomous drive cars like Tesla puts out. I, for one, am glad that our betters leaders gov believes that our safety is of primary concern to them and will do whatever it has to do to save us from ourselves.

    Tesla and Boeing!
    Driving - and flying - you into parked vehicles, other inanimate objects and the ground for a better tomorrow! :righton:

    [​IMG]
     
  6. Wegahe

    Wegahe NRA Instructor

    3,265
    525
    113
    This could be where the problem really is with the pilot instead of the computer.

    The computer senses wrong action by the pilot such as too steep of a climb and makes corrections. The pilot then restores the steep climb. The computer then takes corrective action again. I think I heard a witness had said the plain appeared to be going up and down.
     
  7. Malum Prohibitum

    Malum Prohibitum Moderator Staff Member

    67,050
    1,428
    113
    That's what happened in New York - the pilot kept pulling up and putting the plane into a stall. Probably panicked as the plane began to fall and made it worse by pulling back on the yoke instead of fighting instinct with judgment and pushing the stick forward - it takes guts to push the nose down on a falling airplane.

    Simple but understandable error - 50 dead. A computer override would have saved those lives.

    http://www.cnn.com/2010/TRAVEL/02/02/continental.crash.inquiry/index.html

    Renslow, the safety board said, reacted in a way "consistent with startle and confusion." He pulled on the column, exacerbating the situation and dooming the aircraft, the board said.

    Likewise, Shaw did not "call out" the stall, nor did she push forcefully on the control column as she was trained.

    "There was adequate time for either pilot to take action before the stick shaker (warning)," the board staff said. And there was time for them to take action when the stick shaker activated. Twenty-seven seconds passed between the onset of the warning and the time flight data recorders stopped working, presumably upon impact.​
     
  8. gunsmoker

    gunsmoker Lawyer and Gun Activist

    27,542
    684
    113
    yeah, pilots can make errors in judgement, doing the wrong things unintentionally, negligently, with the flight controls.

    And pilots can be evil. They can choose a murder-suicide scheme where they fly the plane into the ground like a giant missile, in a kamazazie attack on a ground target, or just crash it in the ocean or a farm field where the plane itself and its passengers are the only real targets. This has happened several times before.
     
  9. Wegahe

    Wegahe NRA Instructor

    3,265
    525
    113
    I'm going to go with pilot error on these 737 max crashes.
     
  10. GoDores

    GoDores Like a Boss

    3,034
    85
    48
    Commercial pilot here. I don't fly the big jets but I know plenty who do.

    It's just not the case that there are flight automation systems that can't be disabled or overridden by the flight crew. I'm open to being proven wrong, but your friends will need to name the specific type of aircraft and the name of the system that doesn't allow for manual reversion (it'll probably have an acronym, like the MCAS system involved in the Indonesia and possibly Ethiopia crashes - aviation loves acronyms). It will be easy to look up the operation of that system to find out whether it can be shut off.

    What about that MCAS system? It was added to the 737 MAX because that plane uses larger engines mounted farther forward than previous 737s, which causes a tendency for the nose to pitch up in some flight regimes more so than other 737s. To help prevent an aerodynamic stall, MCAS automatically adds nose-down trim when the plane is in certain flight configurations and a high angle of attack is detected.

    With the Lion Air crash in Indonesia, the angle of attack sensor was sending faulty data that activated the MCAS and added nose-down trim when the angle of attack was not high, ultimately causing the airplane to impact terrain. Pilots transitioning to the 737 MAX prior to that crash were not trained on the existence and function of the MCAS system. But the corrective action is the same as for any situation in which the electric trim is malfunctioning: disable the electric trim. All airliners, including older 737s, have electric trim, and runaway trim is a failure mode that's trained on and practiced in simulators. One of the things I do before I fly an airplane I'm not already familiar with is locate and identify the switches, breakers, and other means of disabling the autopilot and electric trim systems, so I can rapidly shut them down if they start making the airplane do something I don't want it to do.

    In fact, the AOA sensor had been malfunctioning on the three previous flights of the Lion Air accident aircraft, and those crews resolved the situation by disabling the trim. We'll never know why the accident crew didn't take that step, but some of the responsibility for the accident is on them, and some is on Lion Air maintenance for not resolving the problem after previous flight crews had reported it.

    There's no way to know yet if the same system was relevant to the Ethiopian crash, based on current public information. The accident aircraft apparently never reached an altitude at which flaps would normally be retracted, and MCAS does not function with flaps extended. But some FAA statements indicate they think there might be a connection. The flight data recorder on new aircraft collects a ton of information, and I think it's likely that investigators will be able to pinpoint the causes of the Ethiopian crash very accurately once the analysis is complete.

    Would I fly on a 737 MAX if they hadn't been grounded? Based on current publicly available information, yes, if it were flown and maintained by Americans, who I don't think are likely to make the same maintenance and operational errors that Lion Air did. That's the consensus (but not unanimous) opinion from those I've heard from who do fly transport category jets for a living.
     
    moe mensale and Phil1979 like this.
  11. Nemo

    Nemo Man of Myth and Legend

    12,824
    830
    113
    I defer to your knowledge and my airplane rider assessment pretty much agrees with you and is most likely pilot error based on insufficient training and experience in the cockpit.

    Then I will think you are about half crazy man for being a commercial airplane pilot.

    Nemo
     
  12. Wegahe

    Wegahe NRA Instructor

    3,265
    525
    113
    Just heard on the news the PIC only had 200 flight hours.