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    Default Boeing 737 Max

    Another tragic plane crash today with all on board killed. From what I read it seems to be very similar incident to the earlier crash of another almost brand new aircraft in the Phillipines not so long ago. In both cases the aircraft appears to have dived straight down into the sea in one case and into the ground in todays case.


    Are modern aircraft getting to be too complicated and too reliant on computers ?


    My thoughts are with the families of those who lost their lives, Tyrone.

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    my thoughts are too. this is really tragically f---ed up.

    I will be enraged, embarrassed an ashamed at what Boeing has done, if it does turn out to be the same thing as the Lion Air crash (thats Indonesian BTW) it is hard to believe that this would have happened if they were still the same company we knew and loved (or hated), based in Washington state.

    while it is too soon to tell, it sure looks like the same thing. the auto anti-stall fighting the pilot and taking the plane down, possibly due to a blocked pitot airspeed sensor.


    ALL THAT IS NEEDED IS A BUTTON THAT SAYS "AUTO PILOT OVERRIDE"

    a red button under a cover, just like an E stop

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    Quote Originally Posted by cyanidekid View Post
    my thoughts are too. this is really tragically f---ed up.

    I will be enraged, embarrassed an ashamed at what Boeing has done, if it does turn out to be the same thing as the Lion Air crash (thats Indonesian BTW) it is hard to believe that this would have happened if they were still the same company we knew and loved, based in Washington state.

    while it is too soon to tell, it sure looks like the same thing. the auto anti-stall fighting the pilot and taking the plane down, possibly due to a blocked pitot airspeed sensor.


    ALL THAT IS NEEDED IS A BUTTON THAT SAYS "AUTO PILOT OVERRIDE"

    a red button under a cover, just like an E stop
    They have one, all the pilot has to do is push it.

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    Quote Originally Posted by moonlight machine View Post
    They have one, all the pilot has to do is push it.
    what are you a commercial pilot type certified on the 373 MAX now?

    according to press reports, including quotes from Boeing literature, NO, that doesn't work on the auto anti-stall

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    Quote Originally Posted by cyanidekid View Post

    ALL THAT IS NEEDED IS A BUTTON THAT SAYS "AUTO PILOT OVERRIDE"

    a red button under a cover, just like an E stop
    That makes the assumption the pilot can fly the plane by the seat of his pants, which is a whole diffrent ball game in a airliner than it is a cesna.

    I don't think most people realize that every time improvements are made efficiency and performance wise the humans are fundamentally unable to manually fly the things. If you watch any of the airline pilots on youtube, its becoming ever more apparent they more or less fly them like we would use MDI to machine something. There getting ever nearer to the point were a whole flight can just be pre programmed, lots of the flight path is, but theres still more than a few things that change mid root that gives us making parts on a cnc using MDI as the best analogy i know. The days of throw the switch and let the human take control are kinda ending, because the human statistically is the weaker link. If you ever try for your instrument rating you will get a idea why flying by the seat of your pants does not work. Human senses just don't function with out enough visual feed back to ascertain the info. Air speed is one of the key things you have to know to make the tin can or carbon fibre can fly. Ground speed alone is no good, nore is much else, the humble pressure difference on a simple forward facing tube still rules regrettably.

    You have to be going a given air speed at a given altitude to remain air born, the higher you go the faster you have to fly to not be in a stall.

    I believe there is a lock out on the auto stall system, but its a lot lot more than a single button and its done that way for good reasons. There is several steps needed to disable it and you also have to be certain thats what your actual fault is before you turn that off too. Theirs more than a few things that will cause similar flight paths - symptoms and to know its the auto pilot you have to realize more than a few different conflicting things are lying to you.

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    Quote Originally Posted by Finegrain View Post
    Thanks Mike, yea, it's an MCAS cutout, and according to the quotes I read you couldn't just flip a switch, you had to be in a certain mode to enable the switch.

    the scenario that COULD have happened here is terrifying, the pilot pulling up, the MCAS pulling back down, possibly with a delay, the pilot pulling up again, repeat, repeat, and you are staring at the ground about now, and partly because BOEING DIDN"T THINK THE PILOTS NEEDED TO KNOW about the change, they are starting to go into WTF mode, or possibly even panic, at which point the intricate sequence to de-activate may start to get problematic, to say the least.

    this is NOT a situation where the pilot could not fly the plane without the assistance of the computer, it is a situation where the "computer" is flying the plane INTO THE GROUND. about now ill take my chances with the pilot. making it hard to override may have cost 370 lives in the last 3 months.

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    The plane ended up only 30 miles from take off. I doubt the auto pilot would have been turned on so soon. I thought they waited until they were in level flight. But I do not claim to be any expert.
    Bill D.
    Last edited by Bill D; 03-11-2019 at 09:16 AM.

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    Quote Originally Posted by Bill D View Post
    The plane ended up only 30 miles from take off. I doubt the auto pilot would have been turned on so soon. I thought they waited until they were in level flight. But I do claim to be any expert.
    Bill D.
    MCAS is not autopilot. In fact based on the article I linked, MCAS is only enabled when autopilot is off. MCAS is intended to compensate for the MAX version of the 737's tendency to pitch up.

    Regards.

    Mike

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    Quote Originally Posted by cyanidekid View Post
    what are you a commercial pilot type certified on the 373 MAX now?

    according to press reports, including quotes from Boeing literature, NO, that doesn't work on the auto anti-stall
    Not a 737 pilot although I know one and have talked to him about the system after the Lyon Air crash.

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    This is nothing to do with the autopilot. The Boeing bulletin says it can only happen in manual flight.

    It's about the AOA vanes. The Lion Air jet had the left one replaced the day before the crash, and they had made 4 flights with a 20 degree AOA mismatch.

    On 737NG and MAX, the AOA sensors input to the flight control system. If there is a stall warning, the flight controls will put forward pressure on the control column. The pilot can overpower it, but it takes a lot of effort.

    A friend flies 737NG for Delta. He had this happen to him several years ago- also right after taking off. In his case someone on the ground had bumped the right AOA vane and busted it. He was able to muscle it down, but he said it took all he had.

    Earlier versions of 737's only had the pitot system input to the flight controls, so a bad AOA vane didn't affect anything- it just gave an erroneous reading. He didn't understand that the AOA vane was the culprit, because he had a lot of hours on earlier 737's and they were different. No one had ever explained the change to him.

    The pilot can manually switch between the right and left side pitot and AOA sensors, but he has to understand that's what the problem is. There is a lot going on right after taking off, alarms and stall warnings, a jet that thinks it's in a stall, and the pilots don't have any time to react.

    Incorporating the AOA sensors into the stall warning system isn't a bad idea- A lot of people have been killed by iced up pitot tubes too. AF447 pancaked into the Atlantic thanks to a pitot tube.

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    Quote Originally Posted by moonlight machine View Post
    Not a 737 pilot although I know one and have talked to him about the system after the Lyon Air crash.
    Well you're right that the autopilot can be switched off any time, just like the MCAS, the autothrottles, autolanding, and a lot of other systems.

    The MCAS is an autotrim system, and shutting it off won't shut off the anti-stall system.

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    This strikes me as an HMI issue.
    Not the first time an HMI has been a problem.
    Three mile island, Texas city, even other aircraft.

    Training goes a long way too.
    But in a time critical case the HMI has to be perfect.

    There’s a current working group in ISA for industrial systems.
    This is an ad, but covers the core.
    https://www.automation.com/pdf_artic...hite_paper.pdf


    It’s also worth noting that these planes are so optimized the flight envelope is tiny. Asking them dam near impossible to fly manually.

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    Don't know if it was a MAX or not but only last month I flew from Amsterdam to Bangkok and back 2 weeks later in a KLM Boeing 737.

    I'm just going to keep believing that flying is still the safest way to travel. Both there and back we landed ahead of schedule and I'm damned if I'm going to stop travelling because accidents happen. I also believe that aircraft crashes and "incidents" are meticulously investigated to avoid repeats. Aircraft accidents almost always involves many deaths at one time so "big news".

    Transportation safety over time: Cars, planes, trains, walking, cycling - Journalist's Resource

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    Just been on the news that Chinese airline authority have ordered their airlines to ground all their Boeing 737 Max aircraft. 96 aircraft in total.
    This needs sorting out and fast.

    I remember watching a documentary about an aircraft accident where the suspicion was that the manufacturer had balanced the likely cost of paying out compensation in the event of an accident against the cost of putting right a known fault and decided not to do anything about the fault.

    Regards Tyrone.

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    Quote Originally Posted by Gordon B. Clarke View Post
    Don't know if it was a MAX or not but only last month I flew from Amsterdam to Bangkok and back 2 weeks later in a KLM Boeing 737.

    I'm just going to keep believing that flying is still the safest way to travel. Both there and back we landed ahead of schedule and I'm damned if I'm going to stop travelling because accidents happen. I also believe that aircraft crashes and "incidents" are meticulously investigated to avoid repeats. Aircraft accidents almost always involves many deaths at one time so "big news".

    Transportation safety over time: Cars, planes, trains, walking, cycling - Journalist's Resource
    You do get fast does not mean safe, you do get investigated how ever well does not fix the cause and you do get how it may just be safer not to fly on one of the affected models right?

    Again if this is the same fault and bassed on the wacky flight profile it kinda looks like it could well be the pilot is at that moment kinda so busy dealing with issues its hard to detach and look at a complex chain of faults clearly enough to diagnose something like this. When this system goes wrong its not like a fuel gauge hitting empty, you have a whole bunch of different indicators giving you weird readings and a plane that keeps trying to dive, stall warnings etc and every time you correct it it simply dives harder.

    Equally fundamentally you have a plane design that flies so badly - unstably do to simple physics it needs a system like this to be sensibly viable to fly. There is no muscling the controls, the leavers don't connect to fucking anything in a fly by wire system as is on this version of that aircraft!

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    Quote Originally Posted by Tyrone Shoelaces View Post

    I remember watching a documentary about an aircraft accident where the suspicion was that the manufacturer had balanced the likely cost of paying out compensation in the event of an accident against the cost of putting right a known fault and decided not to do anything about the fault.

    Regards Tyrone.
    Yes - this was in the US but I cannot remember the actual case.
    But it set president that there is a maximum payout per person for an aircrash.
    And then it's easy to do a cost compare against fix versus crash/payout.

    All this said, I would always want to fly in a Boeing over a Scarebus.
    I don't know if it has changed, but up to only a couple of years ago, Airbus will never allow full control to the pilot where Boeing will.

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    Quote Originally Posted by Miguels244 View Post
    ...It’s also worth noting that these planes are so optimized the flight envelope is tiny. Asking them dam near impossible to fly manually.
    Not at all true. I have logged several hours in the 747 and 767 full motion simulators at Boeing's training center in Renton, and I can tell you that these jets are very easy to manually takeoff and fly.

    Manual landings are the tricky part- but anyone with the most basic flight experience can fly one. Even someone with no experience can easily maintain straight and level flight- I put my girlfriend in the left seat of the 747 simulator and she had no problems at all.

    Most of the newer ones will also autoland, and the only thing the pilot has to do is engage the thrust reversers once they touch down. They will even taxi to the gate if you tell them to.

    The argument between the airlines and pilots- for a long time now- has been over manual landings. The airlines don't like the pilots to land the planes because a human uses more fuel than the computer. If the autopilot does it all, the throttles come back to flight idle at the beginning of descent, and basically stay there until the plane is on the ground.

    The pilots say they need to do a certain number of manual landings to maintain proficiency, and the airlines want this to be done in the simulators to save money.

    The 777 was the first fully automated FBW Boeing jet, and the joke at Boeing was "The ideal flight crew for a 777 is a man and a dog. The man's job is to watch the computers fly the plane, and the dog's job is to bite the man if he touches anything."

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    Quote Originally Posted by adama View Post
    ...Equally fundamentally you have a plane design that flies so badly - unstably do to simple physics it needs a system like this to be sensibly viable to fly. There is no muscling the controls, the leavers don't connect to fucking anything in a fly by wire system as is on this version of that aircraft!
    No, it's not that way. The planes are not aerodynamically unstable, and the pilots can overcome the stick pusher by brute force.

    Some military jets are aerodynamically unstable- an F-16 for example. Without the FBW, the jet will swap ends in flight. Commercial and civilian aircraft are not designed that way, they don't need that level of maneuverability.

    What happens in this kind of incident is the pilots suffer from information overload. They just don't have the time to assess everything that's happening.

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