back to article Boeing admits 737 Max sims didn't accurately reproduce what flying without MCAS was like

Boeing has admitted that pilot training simulators for the controversial 737 Max did not accurately reproduce what happened if the infamous MCAS system went gaga. In a statement, the American aircraft manufacturer said it had "made corrections to the 737 MAX simulator software and has provided additional information to device …

  1. Alister

    They need a bigger shovel, the hole just keeps getting deeper.

    1. Anonymous Coward
      Anonymous Coward

      "If MCAS is activated in non-normal conditions, it will only provide one input for each elevated AoA event. There are no known or envisioned failure conditions where MCAS will provide multiple inputs."

      Yeah, right, the rest of us know of at least 2 disastrous "failure conditions". Just shut up Boeing, you've done more than enough damage already.

      1. defiler

        That's their sales pitch on the fix. Their proposed software update will limit MCAS to a single movement per event, preventing the ongoing wrestle with trim.

        Still don't know if I'm terribly comfortable with their proposal, though.

        1. Anonymous Coward
          Anonymous Coward

          "That's their sales pitch on the fix. Their proposed software update will limit MCAS to a single movement per event, preventing the ongoing wrestle with trim."

          But will they need to perform a "roller coaster" to unload the control surfaces sufficiently to allow the pilot to recover the aircraft?

          The aircraft hasn't behaved as Boeing, the pilots or aviation authorities have expected and I'm not convinced Boeing have come up with sufficient public explanations to satisfy anyone outside of Boeing executives and airlines that are completely dependent on 737MAX's.

          Mainly because I expect the answers will result in the aircraft needing to be certified rather than relying previous generations airworthiness and lengthy groundings/cancelled orders causing everyone a lot of problems...

      2. EN1R0PY

        That quote was not Boeing defending the old software but talking about the changes in the new release so when you ask them to "just shut up" a la Gavin Williamson would prefer they don't creat fixes at all or they aren't transparent about what those fixes are?

        I get they f'ed up to the extent of people dying and I'm in no way defending that it happened but they are explaining what they have done to try to ensure it won't happen again. How is shut up a helpful response? They also said "failure conditions" not failure examples so unless there was a problem aside from a sensor failing causing a safety feature to misbehave there is only one "disastrous failure condition".

        Its nee jerk responses like this that feed Trump's post truth world. "Have a go at them not matter what they say cos the internet told me to be mad, but forgive the corrupt fascist politicians cos the internet told me to do that too!"

    2. Anonymous Coward
      Anonymous Coward

      The hole does keep getting deeper, and more expensive.

      They've basically just admitted that the Emergency Airworthiness Directive they slung together with the FAA's approval was highly likely (had they thought about it at the time) to turn out to be unworkable. And tragically it's taken the deaths of all those on the Ethiopean aircraft that crashed to demonstrate the point.

      So, if anyone wanted to demonstrate in court that Boeing were asleep at the wheel in their role as OEM Design Authority, this will do nicely. I presume Nader (who is sueing them) has so much material now to choose from that he is spoiled for choice.

    3. vtcodger Silver badge

      Say, what?

      If MCAS is activated in non-normal conditions, it will only provide one input for each elevated AoA event.

      What are "non-normal conditions"? What's an "elevated AOA event?" I understand that every statement has to be vetted by lawyers who are (quite reasonably) concerned about the eventual lawsuits for one hundred gazillion dollars ... per death. But does this actually promise anything meaningful?

      1. EN1R0PY

        Re: Say, what?

        Non-normal is not explicit here, though it is not refering to non-normal sensing as they stated they will deactivate the sensor so it must just refer to a non-normal AoA. AoA is explained in the article, if the Angle of Attack is too high (elevated) the engine will stall. As for defining what an event is in software try a good intro to programming book. It's using technical not legal language, that technical language might be specific to the industry but its not hard to interpret. The system will only try once to correct the plane, it won't keep on trying or retry if the sensor reading continues to show an elevated AoA so the piolets won't have to fight the system. It is believed that the piolets could not regain control which caused the crash, rather than the system activating at all.

        (Why are people misreading this article to create a reason to be mad, Boeing killed people that's reason enough!)

        1. The First Dave

          Re: Say, what?

          So when the plane nose-dives, it is reasonable to assume that the AoA indicator will drop back from the initial reading, resetting the counter to zero again? If MCAS is only allowed to engage once per flight, or say once per hour, then it is virtually useless.

        2. lowwall

          Re: Say, what?

          Excessive Angle of Attack results in an aerodynamic stall, not an engine stall. An aerodynamic stall means there is not enough airflow over the wings to support flight, so down you go. This normally occurs when the nose of the plane is held too high for the engines to maintain airspeed. A stall is normally a recoverable event as long as you have enough altitude. If the plane is level and center of gravity is where it should be, it's actually a non-issue. The nose will drop and once you speed up a bit from falling, there will be enough airflow over the wing for it to start flying again. The Airbus crash over the south Atlantic a few years ago was caused by the computers putting the plane into an aerodynamic stall (due to faulty incoming data from iced over air pressure ports) which the co-pilot (who had command of the controls once the autopilot shut off) exacerbated by holding the stick back until it was too late to recover.

          But this isn't what caused the Max crashes, it was actually an attempt to avoid the above scenario in the first place that did it. The issue on the 737 Max is the engines are mounted further forward than normal. At high power levels (for example during takeoff), this tends to pitch the nose up more than pilots are used to which could eventually result in a stall if allowed to continue. MCAS was designed to counter this by automagically trimming the tail to lower the nose when it detected the nose was too high. In both flights, it appears that a faulty AoA sensor resulted in MCAS repeatedly applying the trim when it wasn't needed. Poor software choices and inadequate training resulted in 2 planes diving into the ground while the crews tried to figure out what was going on.

          Note: depending on how many other engines you have, an engine stall means you are either flying a glider or have reduced power. But the plane is still under aerodynamic control. Sully's "Miracle on the Hudson" along with millions of other successful glider and engine out landings tell us that an engine stall is not a death sentence, just an issue to be handled.

          1. dvvdvv

            Re: Say, what?

            Check your sources — the computers didn't put AF447 into a stall, the pilot did. "The computers" OTOH correctly identified their inability to make decisions based on the available information and put themselves out of the loop.

            1. lowwall

              Re: Say, what?

              dvvdvv is correct, the plane was still under control when autopilot disabled itself. The pilot put it into a stall around 30 seconds later. Sorry, I was doing this from memory.

            2. Justthefacts Silver badge

              Re: Say, w

              Boeing have just ignored the logical contradiction at the heart of this.

              “The system as a whole” requires MCAS for this aircraft to be fully aerodynamically stable.

              It just doesn’t make any sense to disable MCAS. What actions would you expect the pilots to take, that can guarantee to be safe and save the aircraft? It’s not even hypothetical, there are two options, and they have to pick one to write into the Ops Manual. Whichever they pick, everyone on board is going to die with 50% probability in case of a single AoA sensor failure. This is not a credible solution.

              The pilot sees the AOA disagree light, and MCAS disengages. At this point, *one* of the AOA is indicating that the plane is pitching up into a stall, but not the other. The pilot doesn’t know any more than MCAS which one is broken. Either

              1) The pilot guesses that left AoA is correct which claims they are in level flight. They decide not to trim down. 50/50, the left AoA is lying, and the aircraft really is pitching up uncontrollably. The aircraft rapidly pitches up further, making it physically harder to take corrective action, and within maybe 30 seconds the aircraft is not correctable. The aircraft stalls, and If the aircraft is within a few hundred feet of ground (as both of the crashed aircraft were) crashes without time to do anything.

              2) The pilot guesses that right AoA is correct which claims they are pitching up. They decide to trim down, exactly like the MCAS would have. 50/50, the right AoA is lying, and the pilot drives the plane straight down into terrain.

              Boeing are wilfully failing to understand that the AoA sensor is *part of the control loop* for stability. It doesn’t stand outside it, just because there is a pilot in the loop. Therefore, the AoA should follow standard design criteria for safety critical, which is triple redundancy to allow for single failure, plus voting. It really is that simple.

        3. brainyguy9999

          Re: Say, what?

          Stall has nothing to do with the engine. High angle of attack leads to wing stall, which is lack of lift. This is caused by airflow not adhering to the upper surface of the wing. This is caused by air flow being too slow, or the wing being angled too high relative to the forward motion. Air does not adhere to the wing surface and breaks away prematurely, causing lack of lift, causing wing stall and loss of altitude.

        4. the future is back!

          Re: Say, what? A0A stallism

          The engines don’t “stall”, the aircraft does—if the angle of attack goes too high - all a problem due to the repositioning of larger engines for the Max that increased tendency of the nose to be pulled up under high power conditions (takeoff) - this in turn due to Boeing’s urgent need to cut lead time to deploy a new plane that was similar enough to previous 737 models it cut training times as Airbus had leapfrogged Boeing with a new model. Thus a botched and unfinished compromise. Maybe fixed now? I’m taking a boat.

          1. EU time zones

            Re: Say, what? A0A stallism

            Hmm, not correct either. Engines most definitely can stall - it's called compressor stall. It was a huge issue for years on SR71A, and super-stall on rear-mounted planes like VC10 tends to flame out (stall) the engines from the turbulent air from the stalled wings. Side-slipping some military jets also kills the pilot as the airflow into the engine intakes flames them out - they stall.

    4. eldakka

      With the coal mines starting to go out of business, I'm sure they could pick up some massive power shovels (aka steam shovels) for cheap.

  2. Neil McCauley


    What a clusterfuck.

    1. Anonymous Coward
      Anonymous Coward

      Re: ...

      What's "clusterfuck" in the Queen's English please?

      1. BebopWeBop

        Re: ...

        I think that following the example of her gibbon she would pronounce ‘I call this pigs ear Clusterfuck. And may all who perish in her be overlooked’. Queens English enough?

      2. Anonymous Coward
        Anonymous Coward

        Re: "What's "clusterfuck" in the Queen's English please?"

        "What's "clusterfuck" in the Queen's English please?"

        Until relatively recently it would probably have been an omnishambles, but more recently, Saint Theresa May have redefined it.

      3. Rasslin ' in the mud

        Re: ...What's "clusterfuck" in the Queen's English please?

        "Group shag?"

        1. Andy The Hat Silver badge

          Re: ...What's "clusterfuck" in the Queen's English please?

          Until recently it would have been "gang bang" but that's been hijacked by those who think they speak English.

          Quite shocking to hear of a "gang bang on the streets of New York". Jacob R-M's nanny should be covering his delicate ears ...

      4. Pete4000uk

        Re: ...

        'What a lot of unnecessary bother'

      5. Tom Paine

        Re: ...

        Originally "Mongolian clusterfuck"; the derivation's quite interesting, if you like that sort of thing (I happened to look it up a few weeks ago, because -- er -- for work-related reasons. )

      6. This post has been deleted by its author

      7. tony2heads

        Re: ...

        maybe "omnishambles"

      8. Anonymous Coward
        Anonymous Coward

        Re: ...


  3. Anonymous Coward
    Anonymous Coward

    There are quite a few people in Boeing's employment who need to spend some time in prison for cutting corners.

    1. aj69

      Wonder how many engineers are telling the finance blokes: Told ya!

      1. Anonymous Coward
        Anonymous Coward

        Probably none of them, because they know this is the time when scapegoats are being found so everyone is keeping their head down!

        They might try to put the blame on the engineers who raised the warning by claiming "you didn't follow official procedures requiring you to submit engineering risk form XYZ234 in triplicate to designated department heads"

        1. eldakka

          Or where the engineers make copies of the emails they sent detailing their fears before they get 'aged out and deleted'.

          1. Richocet

            Not to say it's the engineer's fault, but one key responsibility of professional/registered engineers is to refuse to sign off on things that aren't safe, even if the CEO orders it to be done. It will be interesting to see if something unsafe was signed off, or if Boeing proceeded without engineering approval.

            A worrying trend over the last 20 years has been systematic undermining of engineer's autonomy to do this. This poses a danger to us all. It hasn't quite got to kidnapping their families and they don't see them again unless they sign off (at least not in Western countries).

            1. Kabukiwookie

              It hasn't quite got to kidnapping their families and they don't see them again unless they sign off

              Yes, they only make sure that you and your family will spend the rest of the next few decades living in a comfy cardboard box, or a nice few decades in a private prison. Either way, you'll never be able to work anywhere as an engineer again.

              Unregulated capitalism, isn't it great?

    2. Cynic_999


      There are quite a few people in Boeing's employment who need to spend some time in prison for cutting corners.


      How do you know how many people were responsible for the decision-making?

      1. Anonymous Coward
        Anonymous Coward

        >How do you know how many people were responsible for the decision-making?

        Do you ?

        Or are you going to believe the Boeing scapegoat story that will inevitably appear blaming it all on the mail room boy who ends up being sentenced to 10 years hard labour while the guilty walk free ?

    3. Magani

      Boeing Score Sheet

      So that's Bean Counters 0; Engineering 1;

      but the travelling public -346.

      1. Anonymous Coward
        Anonymous Coward

        Re: Boeing Score Sheet

        Comedy = Tragedy + Time


        Too soon.

    4. Anonymous Coward
      Anonymous Coward

      AC: "There are quite a few people in Boeing's employment who need to spend some time in prison for cutting corners."

      Many of them appear to be quite busy on the various internet forums. They're easy to identify, combining expert knowledge with bizarre opinions about who is to blame.

      1. dvvdvv

        false flag! false flag!

        Come on, 77th Brigade, that's a cheap shot at the venerable aircraft manufacturer. Everybody knows it's in fact a дезинформационная кампания русских троллей.

  4. Aladdin Sane

    A Seattle based company pushing out half baked software. Who'd'a thunk it?

    1. TRT Silver badge

      It's OK. They've drafted in some expert assistance from a Palo Alto based company that writes autopilot software.

    2. Anonymous Coward Silver badge

      The software was fully baked, it's just that the recipe they followed was shit.

      1. BebopWeBop

        The recipe might have been good but the sensors in the oven were faulty (to stretch your metaphor even more)

      2. chivo243 Silver badge

        The software was fully baked, it's just that the recipe they followed was shit.

        Being Seattle, I bet more than the software was baked on some good shit, Dude!

        1. david 12 Silver badge

          And here, half-baked commentards to feel superior about it.

          1. chivo243 Silver badge

            sarcasm radar built by Boeing? People in high pressure jobs turn to recreational ways and means to cope with everyday life. I won't go into superiority...

          2. Anonymous Coward
            Anonymous Coward

            "...half-baked commentards..."

            I don't always write software, but when I do every single module checks its inputs AND checks its outputs.

    3. SkippyBing

      Technically Boeing is now Chicago based. I'm sure locating the HQ halfway across a continent from where the work is done is unrelated to their current tribulations...

      1. TRT Silver badge

        Nah. It just means a lot of air miles added for the execs as they shuttle between locations in their Lear jets.

        1. werdsmith Silver badge

          Learjet? Boeing executives using products from rival across the border Bombardier?

          Who’d have guessed.

          I suppose a DC9 / 717 would be too big for a couple of board guys.

          1. Kabukiwookie

            Learjet? Boeing executives using products from rival across the border Bombardier?

            Boeing executives flying in their own make of planes? They're just incompetent, not suicidal.

        2. Kubla Cant

          Nah. It just means a lot of air miles added for the execs as they shuttle between locations in their Lear jets.

          I don't think you get Air Miles from journeys in your private plane.

          Or did you just mean flying hours? I can't see a benefit to the execs for being in the air longer.

          1. TRT Silver badge

            Bigger carbon footprint? Does it really matter when it was intended to be a humorous comment? The Wookie got it.

          2. Anonymous Coward
            Anonymous Coward

            never mind air miles, what about cash...

            "I don't think you get Air Miles from journeys in your private plane."

            Depends who you ask, it may not be air miles, it may not be nectar points, but if you ask the right people in the right places, it may be actual cash savings.

            There's a message in there somewhere, and the underlying principles may even be relevant to Boeing management. Something about "the love of money"... I can't remember the rest, and apparently neither can many of the so-called Christians in the US establishment.


            "Lewis Hamilton received a £3.7m VAT refund on his £16m private jet using an Isle of Man scheme, leaked documents reveal.

            The four-time Formula 1 world champion apparently avoided taxes by setting up an artificial leasing business through which he “rented out” his private jet to himself.

            Accountancy firm EY and Appleby allegedly helped him and others set up leasing businesses through which jets were rented, while still allowing them use of the jets for personal journeys."

            (Lewis Hamilton wasn't the only one).

            1. CrazyOldCatMan Silver badge

              Re: never mind air miles, what about cash...

              "the love of money"... I can't remember the rest

              "The love of money is the source of all kinds of evil and many rush into a trap and are lost" is an adequate summary..

              (And I agree with the followon about US 'christianity' - there's another quote that fits "too many corrupt people have seen godliness as a means of financial gain and fallen away from the truth")

              1. Adrian 4

                Re: never mind air miles, what about cash...

                'The love of' is the bit usually forgotten, leaving just 'money is the root of all evil'. This may be Pink Floyd's fault. It may also be true, but misses the real point.

      2. conel

        "Condit makes no secret of another factor: as CEO, he didn’t want to be bothered with tiresome “how-do-you-design-an-airplane stuff,” or boring meetings with Boeing’s key customers (airlines) who came to Seattle."

        1. Kabukiwookie

          Good article. Shows that the focus on profit over safety is not a recent thing.

          After reading this article, the disasters with the 737 MAX seems a natural result of a broken corporate mentality at the top of Boeing.

          1. Adrian 4

            It's not a broken corporate mentality. It's a fully working corporate mentality : profits above everything, especially other people.

      3. DCFusor

        City of Chicago is roughly the center of non-banking corruption in the USA. They wanted to save commute time.

        Like "the City of London" is the center of banking corruption worldwide. USian bankers go there to do their dirtiest deeds (The "london whale" for example - JP Morgan)...and probably other countries as well.

        1. Anonymous Coward
          Anonymous Coward

          I worked at JPM (at Bank St.) You are mistaken.

          1. Kabukiwookie

            I can see why you're posting as anonymous coward.

  5. dvvdvv

    Boeing instructions did say in November:

    Initially, higher control forces may be needed to overcome any

    stabilizer nose down trim already applied. Electric stabilizer trim can be

    used to neutralize control column pitch forces before moving the STAB

    TRIM CUTOUT switches to CUTOUT.

    [end quote]

    The Ethiopian crew just didn't follow them.

    1. Anonymous Coward
      Anonymous Coward

      How does that help if it keeps triggering and adding another 2.5 degrees of trim?

      Would a pilot be able to remove it faster than it was being added?

      Would use of electric trim in the presence of a fault explain the "high sink rate, not so high sink rate, high sink rate (repeat)" profile?

      1. dvvdvv

        You use the electric trim to remove the load and _then_ turn the electric trim off. MCAS doesn't interfere while you're pressing the trim buttons on the yoke.

        1. Colin Bull 1

          As was proved by the Lion Air flight PRIOR to the fatal Lion Air crash and the fatal Lion Air crash up until the pilot gave control to the first officer who did not follow the example of the pilot. (The pilot kept level flight for 22 sequences of MCAS if my memory is correct.) This proves the situation was recoverable if the right sequences were followed. Whether these crews had the training or experience to do this is another matter. Never the less Boeing created a potential disaster through its stupid decisions not to make pilots well aware of the changed characteristics in the MAX.

          1. dvvdvv

            How well should "well" be? All the Ethiopian crew needed was right there in the bulletin issued right after the Indonesian crash. Flight crew complacency is even deadlier than that of the manufacturer.

            1. TRT Silver badge

              Do you happen to have the text of that bulletin?

              1. Anonymous Coward
                Anonymous Coward


                1. TRT Silver badge

                  So basically there are 10 possible indicators of the failure mode requiring this corrective action, and the most reliable of these indicators, the AOA disagree warning, is marked "where fitted". And how many of these indicators are shared with other abnormal flight conditions? It's all well and good saying that the pilots should have followed the bulletin, but there's a certain degree of having to recognise that one needs to do that. Of course now it's all over the news, it's at the forefront of a pilot's mind.

                  1. baud

                    > the most reliable of these indicators is marked "where fitted".

                    In both case (Lion Air and Ethiopian Airlines), this indicator wasn't present.

                  2. dvvdvv

                    It's been in the news since last October/November. Hasn't helped the Ethiopian crew much.

                2. Jakester

                  Really disturbing is the Boeing bulletin which states that 'continuous or intermittent stick shaker..' and 'minimum speed bar..' can occur on '..the affected side only'. Well, that would depend on why the AOA is incorrect and in which position it is incorrect. If the AOA of the affected side is giving a too low indication and the pilot 'corrects' the AOA, then the 'good' AOA sensor would indicate a true stall condition and activate the stick shaker on the 'good' side.

                  I think the bulletin by itself shows that Boeing doesn't have a clue about MCAS, what is wrong with it, or how to fix it. If you (or they believe) what is in the bulletin, then if there is a discrepancy in AOA indications, the side that activates the stick shaker is bad and can be ignored and would be a simple software fix to ignore the AOA sensor that is generating the command to activate the stick shaker. Of course, that makes absolutely no sense.

            2. Anonymous Coward
              Anonymous Coward

              The crew are trained and experienced at handling the plane. What normally happens is you pull back on the yoke (with considerable force) and press the trim button to set that as the neutral position. You don't expect to have to keep doing that. They would be trying to work out why the nose kept getting heavier and heavier. The last thing they are going to think of is that the plane is intentionally ignoring the trim, putting its nose down and heading into the ground.

        2. Tromos

          If there was a way to just turn off the MCAS input to the trim system, you wouldn't need to turn the electric trim off at all. Another fundamental design flaw in my opinion.

        3. Anonymous Coward
          Anonymous Coward

          "MCAS doesn't interfere while you're pressing the trim buttons on the yoke."

          Read the Boeing bulletin on this, why is the above sentence supplied by this person not part of that bulletin. It seems quite important, does it not?

          It should be made 100% crystal clear that pressing the trim buttons will stop MCAS activation.

          The bulletin COULD imply that MCAS will override Electric stab trim, making a pilot more likely to use the stab trim cutout switches in a panic situation.


      2. Randy Hudson

        I thought Denzel Washington already showed us how to handle this scenario.

        1. dvvdvv

          It was Captain Ted Thompson and FO William Tansky,. And no, it didn't work IRL.

    2. Wellyboot Silver badge

      Maybe they were too busy having both pairs of hands pulling very hard on on the stick to keep the beast in the air?

      How about this for a thought process - "When I let go of the stick to flip the 'off' switch we will go nose down because we can't hold it with just 3 hands, so, can we recover to level flight in the few seconds we'll have before impact".

      1. dvvdvv

        This "thought process" is a panic response contrary to their supposed training (the Boeing MCAS bulletin included).

        1. Kabukiwookie

          I thought flight crews didn't need any training, because the flight characteristics of the MAX should have been 'identical' to the original 737.

          1. Mark 85

            Nope, not quite the same flight characteristics. The use of the larger engines meant they moved them forward for ground clearance and thus the CG of the aircraft moved also. This caused problems during the power of climb out. Good pilots (for some value of good...maybe better trained and more experience?) didn't have a problem compensating. However, the trend (just like everywhere else, is towards more automation and thus saving money on training. I can see some parallels here with the MAX and also with the automobile world of "autopilots". The tech really isn't mature enough yet.

            Footnote, there were other options during design such as lengthening the landing so the CG would have to be moved forward. Costs were most likely why they didn't as a software/hardware fix would be cheaper than a redesign to put the CG where it belonged.

            1. DCFusor

              mark, you're missing the point here. Boeing SAID there were no effective differences, other than better fuel economy. It was, of course, a lie. They knew it was different or MCAS wouldn't have been brought into existence.

              As usual, it's the lie that matters here.

          2. dvvdvv

            Flight crew always need training. Particularly when the manufacturer and the regulator issue emergency bulletins.

            1. Jakester

              Assuming much crew training is in simulators and the simulators respond much differently than the plane, the crew is effectively getting trained to crash rather than perform a recovery.

        2. Brit Flyer

          If was no in the US, so who cares?

          There is a lot of talk about how superior US flight crews are etc

          In that case why were all of the "useless" pilots allowed to fly the plane with 2 hours on an ipad.

          The solution is simple , allow it to fly in the US, ground it in the test of the world. When a decent simulator is available and crews have been properly trained then it can fly on probation

          One accident and you are grounded!

          1. Anonymous Coward
            Anonymous Coward

            Re: If was no in the US, so who cares?

            I like the idea of keeping it in the US for a while, but I would suggest we only risk people we can really miss. How well can it replace Airforce One?

            1. A.P. Veening Silver badge

              Re: If was no in the US, so who cares?

              How well can it replace Airforce One?

              Better have it replace Air Force Two. I don't like Trump, but I do admire his insurance policy against impeachment and even assasination (his choice of vice president).

    3. Anonymous Coward Silver badge

      All very well, but they couldn't use the electric stabilizer trim to neutralize it because the MCAS system was already using the electric stabilizer trim to tilt the nose down.

      Computer says down, human says up, computer says down further.

      The only thing left is to either cutout in the fraction of time before MCAS re-triggers, or cutout and manually move the stabilizers back to where they should be. The first option was not practical because the MCAS signals were not rate limited. The second option didn't work because they didn't have enough strength to counteract the aerodynamic forces at that speed.

      1. dvvdvv

        They could. You use the electric trim to remove the load and _then_ turn the electric trim off. MCAS doesn't interfere while you're pressing the trim nose-up button on the yoke, and when you let go of the button, the MCAS rate _is_ limited, so you've got plenty of time to turn it off before the trim moves too far, and have the trim in the range where it's easy to trim manually.

        1. TRT Silver badge

          That might work. It's also a very shit way of achieving something that should not need achieving in the first place. It's the airline equivalent of thumping the TV in exactly the right spot to fix the colour, only 150 plus people aren't going to die if Dot Cotton's dress is the wrong shade of blue.

          1. dvvdvv

            Well, yeah, none of the occurrences you see daily on should have happened, requiring the crew to achieve what should not need achieving in the first place. And yet there they are. The flight crew are there for a reason.

            1. Olivier2553

              You mentioned AVH, so you have read enough to know that system should be designed with redundancy to avoid input error. So why MCAS was originally designed to use only one AoA sensor?

              1. dvvdvv

                I don't remember AVH having an answer to that.

        2. Anonymous Coward
          Anonymous Coward

          Stop getting hit by my fists.

          Yes, and all those who get stabbed can easily jump out of the way.

          The system is designed to fail and designed to fail poorly. Why?

          1. dvvdvv

            Re: Stop getting hit by my fists.

            Obviously, because Boeing engineers are not as perfect as you are. Come to think of it, Airbus engineers are not as perfect either — they just been a bit lucky when their version of stall prevention system failed on D-AIDP in November, 2014. So yeah, both the industry behemoths should put your perfect self in charge of the system.

            1. Kabukiwookie

              Re: Stop getting hit by my fists.

              Please stop making up excuses for Boeing and attempt to divert attention with whataboutery.

              1. dvvdvv

                Re: Stop getting hit by my fists.

                I'm sorry about your attention, but no.

            2. JassMan

              Re: Stop getting hit by my fists.

              More than just lucky, they have 3 AoA sensors not just 2. In fact they were unlucky because 2 froze at the same value and the software logically chose the 2 which read the same. Also on an Airbus, you can switch off each of the probes individually to find which ones don't respond when you make changes to your flight controls, thus giving time to diagnose the problem.

              Furthermore Airbus issued an an Emergency Airworthiness Directive within 35days instructing pilots how to overcome the problem rather than pretending that the first incident was either pilot error or mechanical failure.

              1. dvvdvv

                Re: Stop getting hit by my fists.

                First, the Airbus dropped 4000 feet before the pilots cold arrest the descent. Second, it took the crew and the company engineers more than half an hour to make the airplane behave again — and even then they got lucky, as they turned off the only air data reference unit (not just a probe) that provided correct data, but it still helped as one of the erroneous ADRs had already been turned off, and the stall prevention system required at least two ADRs working in agreement. (BTW, the system correctly identified the same probe malfunction in the AF447 case, but we all know how _that_ ended ). Third, Boeing and FAA issued an emergency AD much sooner than 35 days after the Indonesian crash, 9 days to be exact. Fourth, did I mention the Airbus dropped 4000 feet uncommanded?

                1. Anonymous Coward
                  Anonymous Coward

                  Re: You are Mr...

                  You are Mr "Two wrongs make a right!" and I want my £5 cheque.

                  Oh, you obviously have a case of pointing at the other party? Or vested interests? Or looking to move blame/jump on the "but they are doing it Sir" bandwagon?

                  1. dvvdvv

                    Re: You are Mr...


        3. Anonymous Coward
          Anonymous Coward

          Boeing's IT department should stop posting here and making the situation even worse.

          1. werdsmith Silver badge

            Yes, some random keyboard mash name blames the pilots whilst the professionals in the aviation safety world point the finger at Boeing.

            1. dvvdvv

              Knowing for a fact that the nickname I'm using here is anything but random, I'm pretty sure you have as much clue about aviation safety as about that nickname.

        4. Adrian 4

          You might expect that flight crew have read the technical bulletins.

          It might be unreasonable to expect them to understand the system design so well that they can defeat the system by carefully tricking it into not being able to do what it's designed to do.

          20-20 hindsight.

    4. BebopWeBop

      Obviously - that Ethiopian crew of experienced pilots just didn't know? I am sure a western crew would have done so much better - but no one tested that out in real life... Ok, most pilots don't actually have to deal with a real crisis - but the point of the training is to PREPARE them for it. Boeing did not. For reasons I am, sure will become clearer.

      1. AmenFromMars

        "For reasons I am, sure will become clearer." - money

        1. DCFusor

          Boeing's whole lie was intended to PREVENT the requirement to retrain or recertify pilots and plane.

          Which saved everyone a ton of money, or so they thought. The whole point of the changes to the plane was to save fuel costs for crying out loud. You don't have to look real hard to see cui bono.

      2. Justthefacts Silver badge

        Why did AOA disagree......

        We’re also missing the deeper question. We don’t know why AOA disagreed, and how many possible causes. It’s not likely that AOA disagree multiple times on *several fairly new* aircraft, including in the USA and Canada, as a random sensor failure. And if it is random, at the implied rate even a triply redundant system would fail in a population of a thousand aircraft every couple years, so that’s not good enough. Something is catastrophically wrong. There is a root cause we don’t understand.

        Additionally, if there can be *any* aerodynamic situation where the plane is going towards stall (which is what MCAS is there to prevent) which also causes AOA disagree, then the pilot is just totally shafted. Because the only thing you can ask of the pilot in that circumstance is to do something that is *different from what MCAS would do*. And in that situation, we have just established the plane is into positive aerodynamic feedback, nosing up into a stall. If the pilot trims up he stalls, if he doesn’t he nosedives.

        Translation to softie-land: how impressed would you be by a developer who when faced with a regular crash due to unhandled malloc() failure, just added the handler and called the bug “fixed”?

    5. Fursty Ferret

      You've got to remember that the 737 is almost impossible to fly in a mis-trim situation. It will take one - possibly both - pilots all their strength just to have the aircraft in a vaguely flyable state.

      So you follow the memory items on the stabiliser runaway checklist, then discover that you can't trim manually due to aerodynamic forces on the stabiliser. Rinse and repeat. There's a way of dealing with this situation but it's never been taught to you and removed from the manuals 30 years ago.

      How much mental capacity does this leave for troubleshooting? Not much. Despite the adrenaline your physical strength is starting to wane. You try to enable the electrim trim. Even during this brief moment the computer aggressively runs further nose-down trim input and makes the situation worse.

      It's a brave person that looks at the available evidence here and gives themselves the role of Judge Judy and executioner,

      1. Anonymous Coward
        Anonymous Coward

        So you follow the memory items on the stabiliser runaway checklist, then discover that you can't trim manually due to aerodynamic forces on the stabiliser. Rinse and repeat. There's a way of dealing with this situation but it's never been taught to you and removed from the manuals 30 years ago.

        Also, that way assumes you still have enough altitude to get the pressure of your tail, retrim and then repeat. Trim is high geared exactly because of the high forces on it, so you won't manage this in one go - you need some 3 minutes of cranking to undo what MCAS does with motors in about 5 seconds.

        I think they did some tests on this - apparently you need to be at least 8000 ft up in the air to recover a reasonably trimmed state. That's a luxury neither of the two cashed planes had :(.

      2. dvvdvv

        Which part about dealing with MCAS was removed from the manuals 30 years ago? And at which moment the electric trim was re-enabled with MCAS worsening the situation?

        1. Cem Ayin

          "Which part about dealing with MCAS was removed from the manuals 30 years ago? And at which moment the electric trim was re-enabled with MCAS worsening the situation?"

          The reference is (obviously) not to a method for "dealing with MCAS" but to the "roller coaster" technique of recovering from a severe mistrim.

          As for the de-activation of stab trim cutout, this appears to have happened around 5:43:11 when electric ANU trim was recorded, only to be followed by disaster when at 05:43:20 the stabilizer briskly started moving in AND direction again in response to auto trim input. Possibly the FC tried to flip only the left cutout switch back to "normal" in a desperate attempt to re-enable electric trim without re-engaging MCAS, a misconception that might have arisen from the different functions of the two cutout switches on prior 737 models (where the right cutout switch would disconnect the auto-pilot input only while leaving electric trim engaged).

          See the following references:

          1. dvvdvv

            How much of a "roller coaster" can you do at 2000' to 5000' AGL above a very mountainous terrain? And they didn't need it, anyway — all they had to do was use the goddamn ANU button. Just like Boeing and FAA wrote in November. And the button was perfectly functional when the electric trim was on (see 05:40:14 and 05:40:29), right before they cut the electric trim off.

            Nothing happened at 05:43:11. There were two senseless clicks on the ANU button at 05:43:14 and 05:43:15, followed by apparent re-enabling of the electric trim in the next two seconds. MCAS, of course, kicked right back in, but there were no input on the ANU button anymore. I would guess full-on panic had already set in by then.

            1. Anonymous Coward
              Anonymous Coward

              Pre tell.

              How were they to know about this MR Dvvdvv "knows better than Boieng in the comments" method of recovery? How would they know to do that?

              1. dvvdvv

                Re: Pre tell.

                I don't know who you're talking about.

        2. Fred Flintstone Gold badge

          How much are you paid by Boeing to pretend you lack comprehensive reading abilities?

          Is your day job telling people that the Mueller report is a total exoneration?

          1. dvvdvv

            Feel free to subpoena my financial records.

    6. usariocalve

      At ARS there was a mention that the system might have re-enabled itself, but I didn't see that in any other discussion of the incident.

      1. Anonymous Coward
        Anonymous Coward

        MCAS was designed to re-enable itself after some 5..10 seconds after power up (read: re-enabling the trim motors, they were on the same switch). So you'd kill the power, switch it back on and everything would appear normal while you were frantically trying to get the plane back into trim.

        After 5 seconds, MCAS would then kick back in and undo any trim status recovery you just managed.

        The result of all this is that you're now in descent at an angle that gets you an airspeed that exceeds specification, with a trum that seems to have a life on its own when you give it power, and which is now hard to move manually due to the forces on it.

        Yet still, there are some people alleging it's all perfectly fine and pilots should have figured out that Boeing had been idiots so they had to flip trim power off and on in 5 seconds intervals because. there. was. no. way. to. kill. only. MCAS.

        If you boil it all down, the key reason why almost 400 people died is because Boeing though that adding a separate MCAS switch would cost them money (in various ways). If there had been a separate switch to disable MCAS it would (a) made pilots aware that there was a ghost in the machine and would (b) immediately create the assumption that the trim problems must be because of a new gadget they didn't know much of because that's pretty much the default assumption when a tried and trusted "identical" airframe suddenly misbehaves. That's the sort of human factor they study in air safety..

  6. ForthIsNotDead

    The corrections and modifications and to the software that they are quoting sound like they are normal fail-safe type functions that should have been in the software IN THE FIRST PLACE. How this system/software EVER got certified is beyond me. How did it EVER pass a HAZOP? Were they all asleep?

    Something's not right.

    1. TRT Silver badge
    2. Geoffrey W

      I believe that Boeing were allowed to certify their own plane as air worthy. Under funding of the FAA led to the FAA relying on Boeing to do the FAA's work for them. That is my understanding. Couple that with Boeing's desire to get something out quickly to compete with Airbus's new fuel efficient air craft which was already being delivered, and...

      1. ecofeco Silver badge

        This is correct.

    3. Korev Silver badge
    4. Kabukiwookie

      Easy if you are allowed to self-certify.

      Just like banks are allowed to self-regulate, the US now allows plane manufacturers to self-certify.

      What's the worst that could happen?

      Oh, wait....

      1. ecofeco Silver badge


    5. Olivier2553

      FAA is about as useful to aviation certification as FCC is to telco regulation... Do you mean you are really surprised?

      1. Kabukiwookie

        The US is has entered a period of late-stage unregulated capitalism.

        As Adam Smith made clear in his 'Wealth of Nations' capitalism can only work if there are strict regulatuons that ensure competition in the market.

        Unregulated markets result in monopolies that destroy any sembalnce of a 'free market' (so far as one exists to begin with).

  7. Blockchain commentard

    Even if they do sort it out, how many passengers are going to trust flying in these planes? Boeing should just scrap them.

    1. Thought About IT

      Most people buy a ticket, having no idea which plane they'll be flying in. A bit like those who vote for a party with no manifesto, policies, or members, because they think it'll get them to their destination.

      1. Kabukiwookie

        I will definitely be checking that and will explicitly notify any travel agent that I will not fly in any 737 max (or any new Boeing that comes on the market in the future).

        It seems clear that Boeing puts profits over safety. This will not change until the FAA resumes its previous role, which will probably never happen.

        1. ecofeco Silver badge

          It seems clear that Boeing ALL American corporations puts profits over safety.


      2. SGWilko

        "Most people buy a ticket, having no idea which plane they'll be flying in."

        Most people USED TO buy a ticket, having no idea which plane they'll be flying in. Reckon they'll be paying a bit more attention when booking and choosing a carrier based upon fleet going forward......

        1. seven of five

          Absolutely. No point in saving a tenner if I might fucking die for it.

        2. Mark 85

          Reckon they'll be paying a bit more attention when booking and choosing a carrier based upon fleet going forward......

          Don't hold your breath or bet the family home on that one. People don't even care which airline they on much less which plane because they want their travel schedule to be met.

          1. Kabukiwookie

            People don't even care which airline they on much less which plane because they want their travel schedule to be met.

            Not sure if you're from the US; from what I understand all US carriers are shite and on certain routes you just don't have a choice anyway.

            On the other hand, if you have any experience flying with airlines outside of the US, I can assure you that it definitely makes a difference which airline you're using.

            1. werdsmith Silver badge

              I’m aware of what equipment is in the fleets of airlines that I tend to use and what routes they tend to use them on.

              I sometimes choose a particular airline / flight because I know they usually operate their newer fleet on that route with better in flight entertainment.

              If you are able to choose a seat number, then you are probably flying on known equipment.

      3. MrXavia

        I usually check what plane i'm taking, because different planes mean different layouts etc...

        Sure many people will still fly 737 Max, and I bet after the updates and re-training the software will be safe...

        But I am more worried about the rest of the aircraft, not the software now, where else did they cut corners to catch up with Airbus for this class of aircraft?

      4. Steve 114

        Witches' marks

        People who look before boarding and see double winglets, and frilly jet exhausts, might just panic. Easy enough to spot, and you might get some mass-hysteria and fainting.

        After my friend went down in the DC-10, I never went MD again (I wasn't scared, I just didn't ever want to see the same view she'd had).

      5. Anonymous Coward
        Anonymous Coward

        Do you mean democrats who only have "anything but whatever that guy wants" as their only policy?

        (Even if they wanted it before, now it's a nazi or something)

    2. Morten Bjoernsvik

      737MAX will be safe

      This will be the safest plane ever once AOA has completed the re-certification.

      Certifying a new passenger aircrafts take years. No cutting corners this time.

      Wont be flying before 2020.

      1. Mark 85

        Re: 737MAX will be safe

        This will be the safest plane ever once AOA has completed the re-certification.

        Certifying a new passenger aircrafts take years. No cutting corners this time.

        Wont be flying before 2020.

        Would you bet your life on that assumption? I'm willing to bet it'll be fast tracked and only focused on the MCAS system.

        1. MJB7

          Re: 737MAX will be safe

          "I'm will to bet it'll be fast tracked".

          It may be fast tracked by FAA, but I can't see any of the other aviation regulators being quite so happy to rubber-stamp an FAA approval in future.

          Boeing may be able to get it approved by one regulator (eg Europe), and then have the others rubber-stamp that. But that first approval is going to take years.

  8. TheRealRoland

    If it was implemented as the plane's software was designed, would this have happened?

    "The plane did what during your last simulated flight? Nah, must be a bug in the simulation software."

    1. SkippyBing

      The main issue in the simulator wasn't the MCAS software but the physical effort required to move the trim wheel. When seriously out of trim applying elevator input to counteract the pitching moment creates sufficient force to jam the screw-jack that operates the trim, this makes it effectively impossible to manually trim. This was known about on the early 737, but the detail seems to have left the flight manual in the later 70s/early 80s. It advised relaxing the elevator force, trimming like a bastard, and then reapplying elevator before too much height was lost...

      Apparently the simulator doesn't recreate those trim forces, which means no one really knows what they're going to experience.

      1. Brit Flyer

        Work out required

        Maybe you will need an extra qualification to fly the MAX , to be a body builder.

        This really is a throw back to the 1960s. Parts of it belong in a museum.

        1. Merrill

          Re: Work out required

          I would think that most females and slightly built Asians and East Africans should not pilot MAXs. Pilots should resemble NFL defensive linemen.

          A backup system of mechanically operating the tail surfaces may have been OK on the early, small 737s, but that is a strategy that fails on later, bigger models unless you impose severe physical strength requirements on the pilots.

      2. jtaylor

        I wonder if the sim accurately reproduced how MCAS would trim down repeatedly until impact.

        (For that matter, I don't know if this type of fault is practiced in sims. Control failure, engine out, instrument loss, etc, sure. That's losing systems. What about sensor disagree if it's not presented to the pilots?)

        1. robin48gx

          When I worked on SIMS years ago we used to play disaster landings as a game after work on an faa phase 3 757 in Miami airport. Put the plane 5 miles out heavy mist. Then as they are lining up on descent path put an engine on fire, then give them micro burst (massive downward wind) then maybe a tough crosswind for final landing. We never even thought of automatically making the elevator tri m keep slamming the nose down with the pilot straining at full strength to pull up! That would have just been too silly to believe!

  9. astounded1

    Just In Time - NOT

    I'm sure the fix, if there is one, will come as good news to the folks on the two planes. Oh, wait...

  10. Will Godfrey Silver badge


    I wonder how far they had both arms forced up their back while being held in a stranglehold.

  11. Mystic Megabyte

    Can we have a specially big Boeing FAIL icon please?

    "We continue to have utmost confidence in these aircraft."

    Sorry Mr. Ryanair but I do not. Boeing have spouted enough B.S. already. The plane is a kludge held aloft (or not) by more kludges. Should be scrapped!

    1. FrogsAndChips Silver badge

      Re: Can we have a specially big Boeing FAIL icon please?

      I don't mind, Ryanair is on my no-fly list anyway, for reasons that predate the MAX accidents.

      1. Korev Silver badge

        Re: Can we have a specially big Boeing FAIL icon please?

        Mine too. I stopped wanting to use them after they tried to introduce (illegal) charges for wheelchairs

  12. fidodogbreath

    Software problems have big repercussions in the real world.

    Indeed. "Move fast and break things" translates poorly to scenarios like aircraft design, industrial control, driver assistance, etc. where sloppy code, arbitrary deadlines and poor testing can kill people.

    1. Anonymous Coward
      Anonymous Coward

      Define Death

      One is: meatbag in aluminum tube falls out of sky, meatbag is mangled, meatbag ceases correct operation.

      There is another nuance. Suppose we value a person at e100K/yr. So, one life is worth (making many assumptions with all that means) e5M/life (presuming 80 yr life, 20 yr training, and 10yr "retirement"). We'll call these finlifes, goes with fintech craze in naming.

      So Boeing saves perhaps 100-200 finlifes by bumbling the design of the 737max, and the world loses... several hundred at least finlifes between the actual meatbags lost, the cost of the planes, the lawsuits, the finlifes of people doing the investigation and suing and redesigns. We'll ignore all the finlifes we are spending reading and commenting on the situation-- after all half the people would do even worse by blowing finlifes on cat videos.

      1. Anonymous Coward
        Anonymous Coward

        Re: the value of

        Isn't something along those lines historically referred to as the "Pinto picture"? Where did that end up?

  13. chivo243 Silver badge

    Boeing what are you doeing? or not doeing? Doeing what you are not your supposed to, or not doeing what you're supposed to?

    I'll be goeing now...

  14. Miss Config

    Profit Before Safety

    When an aircraft company for a microsecond puts its own profits before the passengers flying its aircraft then it is truly fucked.

    That certainly happened here when Boeing threatened to CHARGE its customers for the software to correct this problem.

  15. Brit Flyer

    Boeing - would you buy an aircraft from them?


    How can anyone unless they are a profit mad airline believe anything Boeing says.

    Keep the damn thing grounded and Boeing should be forced to recertify the whole plane as a new type. Only when independent experts have gone over every inch of this bodge job can we be sure there are no more nasty surprises.

    Black the MAX

    1. JassMan

      Re: Boeing - would you buy an aircraft from them?

      The problem here is that recertification won't fix the underlying problem. Nor will the supposed software fix.

      The real problem here is that the plane has been designed to be dynamically unstable - something which should only be done in military aircraft.

      There are only 3 possible fixes for this plane:

      1) completely change the wing section so that the center of lift moves backward with increasing speed - they can't increase ground clearance as the undercarriage has already been stretched to its limit.

      2) change the engine nacelles to reduce lift as the airspeed increases.

      3) swap the engines for ones with a smaller fan so they can be brought back under the wing, instead of being stuck out in front.

      The problem is that all 3 fixes will reduce the efficiency of the plane which is how Boeing got into this problem in the first place. They should have just accepted that the 737 has come to end of its life and no trivial adjustments will improve its environmental impact.

      1. werdsmith Silver badge

        Re: Boeing - would you buy an aircraft from them?

        The aircraft is not dynamically unstable, the max just behaves differently from earlier 737s in certain phases of flight. Because it behaves and handles differently it needs a kludge to bias controls to make it feel like a 737 would In those flight phases thus not requiring crew training or certification as a new type.

        If that kludge was not used, the pilots could be trained to accept and deal with the pitch up under power behaviour and there would not have been two fatal crashes.

        1. Ben1892

          Re: Boeing - would you buy an aircraft from them?

          I've always wondered why they didn't just have a stall warning alarm and allow the pilot to pitch down / throttle as required

          1. werdsmith Silver badge

            Re: Boeing - would you buy an aircraft from them?

            Because then it wouldn't be behaving like the 737 type and would require more expensive certification process and airlines would be required to pay for pilot training.

        2. -v(o.o)v-

          Re: Boeing - would you buy an aircraft from them?

          The "kludge" you speak of is an actual FAA certification requirement regarding stick forces, not just to make it like the other 737 in the family.

  16. Dwarf

    Anyone else spotted this ??

    The list of changes from the patch seems to be missing one key line.

    1. Stop flying the plane into the ground and killing everyone on board

    You also have to hope that they realise that its a good idea to stop putting safety above profits. If there was an option that was only safe if another option was fitted, then you have to wonder how many other "options" are on the plane that really should come with all the other pieces of the Meccano kit that makes it a full working capability.

    1. Martin an gof Silver badge

      Re: Anyone else spotted this ??

      Regarding "options", maybe they've taken a leaf from car manufacturers. Bought a car some years ago where if you wanted the air conditioning option, you had also to have the opening tailgate window option. No idea why those two were linked.

      Bought a car more recently where if you wanted the sat-nav option, it came with a speed limit recognition system which cannot be (permanently) switched off. The latter works using a combination of GPS and an onboard camera and frequently gets the current speed limit wrong - particularly in town, when it recognises signs on side roads, and on motorways when it often misses temporary limits on overhead signs, or recognises them briefly then reverts to 70mph, presumably on GPS. It's mainly just "annoying" as it flashes up a red warning on the central display, but it's also possible to link this limit to the speed limiter (fortunately optional). Imagine driving along a 40mph ring-road, and the system seeing a 20mph limit on a side road and suddenly the car starts slowing down.


      1. DryBones

        Re: Anyone else spotted this ??

        And you -bought- it? They'd have to pay me to take some crap like that.

        And then I'd just disconnect some cabling.

        1. Martin an gof Silver badge

          Re: Anyone else spotted this ??

          Well it wasn't entirely my decision. The car belongs to SWMBO, who fell in love with the demonstration model, and our 20-minute test drive didn't throw these things up as big problems. The model we ordered - which didn't have this feature anyway - was not available, though the garage had assured us it was when we ordered it - as in, a pre-built car already somewhere in the country, rather than having to order it from the factory and wait 12 weeks or whatever.

          So a week or so after ordering, the garage rang and said "we don't have the exact model you ordered, but you can have this other model which has had some factory options pre-fitted, at no extra cost". Bingo.

          So far, the response from Citroën has been "please send us a photograph of the problem".


  17. TopCat62

    Bring back Richard Feynman.

  18. Some Random Kiwi

    You know who ought to be on the checkout flights?

    Boeing's senior execs, the FAA management and safety inspectors, and the software engineers responsible for the patches should be on all the checkout flights where they intentionally cause AoA sensor disagreements and dual AoA sensor failures.

    1. Korev Silver badge

      Re: You know who ought to be on the checkout flights?

      John Gummer can provide the burgers

    2. chivo243 Silver badge
      Thumb Up

      Re: You know who ought to be on the checkout flights?

      @SRK tl:wt too long:won't type

      This is a stroke of freakin' genius! I'd like to see some Cs and Ds serving drinks and snacks. Then they can sit in Coach for 9+ hours with the seat in front of them reclined with my kid, his friend sitting in front of them. Those boys know how to crank up the laughter!

  19. Anonymous Coward
    Anonymous Coward

    Of course RyanAir will want them!

    I suspect they plan to charge people extra to use another plane than the MAX..

  20. defiler

    So the simulator disagrees substantially with reality?

    Well what use is the simulator then?

    1. robin48gx

      Re: So the simulator disagrees substantially with reality?

      Prob not faa certified

  21. Anonymous Coward
    Anonymous Coward

    lets see all those smart-arse American pilots who claimed it was all the foreign pilots fault, and they could have saved the planes from crashing do it in properly configured simulators.

    Its everyone else who will be laughing now, when they crash their planes in the same circumstances.

    1. werdsmith Silver badge

      The flight training industry in USA is th biggest in the world, many “foreign” pilots are trained there.

      1. A.P. Veening Silver badge

        The flight training industry in USA is th biggest in the world, many “foreign” pilots are trained there.

        And the reason for that is money, it is a lot cheaper to send pilots abroad for training than do the training at home. I wonder if there is any relation between the quality and the price.

      2. Kabukiwookie

        The flight training industry in USA is th biggest in the world

        I heard it was yuuge.

  22. ecofeco Silver badge

    So much for "you're holding it wrong"

    A few of us said it was the software. The shouty bots said nay.

    Well well well.

  23. TeeCee Gold badge


    "We continue to have utmost confidence in these aircraft."


    "These things are really bloody cheap."

  24. dak

    The People's Airliner?

    Reading some of the comments above, there seems to be a percentage of commentors who think that the problems arise from Boeing being a commercial concern, driven by profit. (Apparently Airbus seem to be given a bye because of the EU's pseudo-direction of the company.)

    This has been a long standing discussion in aviation. Could I please suggest that anyone holding that opinion reads up on the story of the R100 and R101 airships, built in tandem to exercise just that question?

    1. Olivier2553

      Re: The People's Airliner?

      Boeing being a private company, they are of course driven by profit. But in the past they appear to have more concern about safety than about the wealth of their shareholders.

      Boeing is not the only private company going into that direction, many, most, are. And Boeing is not the only company that suffered severe draw backs from that policy of putting profit before quality. Only, Boeing is not selling badly designed washing machines.

      1. dak

        Re: The People's Airliner?

        I'm a Test Manager (mostly).

        To me it's very obvious why these crashes happened. Boeing are not the only company to skimp on testing spend (apparently). But they are in an industry that really can't afford to do so, for either human or financial reasons.

      2. herman Silver badge

        Re: The People's Airliner?

        Err... Boeing is a public company.

        Boeing Co

        NYSE: BA

        353.75 USD −5.05 (1.41%)

        22 May, 1:14 PM GMT-4

    2. Anonymous Coward
      Anonymous Coward

      Re: The People's Airliner?

      There's always a conflict between safety and cost, doesn't matter if it's Boeing, Airbus, NASA, Ford, Mr Kipling..

      However, in the case of Boeing, the FAA was supposed to exercise a watchdog function to ensure they stuck at least to some basic rules. Boeing made the initial mistakes by changing flight characteristics and then adding some MCAS sticky tape over the top without telling anyone that it had done so, but the FAA should have asked why a function that was apparently essential to prevent a stalling condition wasn't even following the most basic rules of redundancy, yet had the ability to FULLY override pilot input?

      Security goes in cycles. All start off with the best intentions (or at least best supervision) and over time people grow lax. Good procedures slow down that process, but without the occasional jolts eventually things go sloppy. The cycle tends to restart after a dramatic near miss - or when is goes drastically wrong - usually, with perfect 20/20 hindsight, "the signs were there" but they're rarely picked up on until it's too late or almost too late.

      Classic old example: MS Harald of Free Enterprise. After that, improvements were made (i.e. costs were allowed because it would otherwise have sunk the company, pardon the pun) so the cycle restarted. However, we've had plenty of ferries sunk since as the local cycle neared its restarting point..

      It is my hope that someone clever comes up with a way to watch the watchdogs so they will not get compromised. In this case, a government sought to save money, and so fatally affected the control function it was supposed to have (not to mention the conflict of interest there). I'm not quite sure how that can be fixed in a way that prevents a repeat.

      Boeing management certainly carries the burden of blame here, but the FAA is not walking away from this with clean hands either.

      1. A.P. Veening Silver badge

        Re: The People's Airliner?

        It is my hope that someone clever comes up with a way to watch the watchdogs so they will not get compromised.

        "Quis custodiet ipsos custodes".

        Yes, the ancient Romans already recognised that problem and they probably weren't the first.

    3. dak

      Re: The People's Airliner?

      Downvotes? Why?

      Do none of you know about those airships?

      1. A.P. Veening Silver badge

        Re: The People's Airliner?

        Those airships are irrelevant.

        Reading some of the comments above, there seems to be a percentage of commentors who think that the problems arise from Boeing being a commercial concern, driven by profit.

        We all understand Boeing needs to make a profit to stay in business. And Airbus has the same "problem". The real problem is that currently Boeing is prioritising profit above safety.

        1. Anonymous Coward
          Anonymous Coward

          Re: The People's Airliner?

          The real problem is that currently Boeing is prioritising profit above safety.

          .. and is prepping for its legal battle by seeding public discussions with arguments that almost make Trump appear logical and reasoned..

    4. werdsmith Silver badge

      Re: The People's Airliner?

      If nobody wants to fly on your planes then there's no profit.

  25. A.P. Veening Silver badge


    Situation Normal, B...

    I will leave the rest as an exercise for the student before I get censored again.

  26. -v(o.o)v-

    Oh, the mythical Max simulators, of which probably 1 exists outside of Boeing??

    1. Anonymous Coward
      Anonymous Coward

      Easy. Make them run on Windows. Voila, random crashes added.

      Just ping me if there's anything else I can help you with.

    2. Robert Sneddon


      There are only a couple of 737MAX simulators i.e. built specifically to train MAX pilots. All modern 737 simulators can emulate the MAX's odd handling characteristics in a high-speed stall which triggers MCAS. It seems, though that they don't properly simulate the forces required to manually trim the elevators when the MCAS/electric trim is disengaged at high airspeeds.

      At high airspeed the aerodynamic forces on the elevators means it requires more effort to manually trim than at lower speeds. Usually a stall happens when the airspeed drops and manual trimming doesn't require a lot of effort in that situation. The MCAS problems occur when the nose of the aircraft is indicated to be too high by the Angle-of-Attack (AoA) sensors in high-speed flight with lots of engine power available making it more difficult for the pilots to trim the elevators manually after disengaging the electric trim capability which is the only way to "switch off" MCAS. Close to the ground, as was the case in both 737MAX accidents, the time and effort required to make the manual trim adjustments were insufficient.

      1. -v(o.o)v-

        Re: Simulators

        I am *very* well aware of this Max issue. See my post history.

        Boeing actually did test the aerodynamic forces on the STAB and apparently a fairly big woman could not move the trim wheel in a test bench at high air speeds and trim near extreme.

        This, as we all know now, did not change anything at Boeing.

        FAA requires the operation to be possible "without exceptional skill", Boeing failed on this with the trim wheel. Yes, there is the "rollercoaster" maneuver that might not be possible in 4000' and IIRC was not included anymore even in the NG FCOM...

        Regarding your last sentence, I actually disagree. The Lion Air crash flight had the captain successfully fight MACS 20+ times before the FO lost it. The flight before on the same plane landed, thanks to a jumpseat pilot.

        My point is that there is some truth to the "just fly the plane" adage. Both accidents indeed were chains of events. Boeing was the biggest culprit here but an "above average" pilot could have saved the flights, perhaps with some luck.

        Just keep hanging the ANU trim switch, not a half-a**ed blip here and there.

        Both airlines have serious issues (as do Boeing and the FAA), flying to destination with stick shaker on all the time?? Hello? Trying to engage AP with stick shaker on? and not following the *memory items* for unreliable IAS (power, pitch)?

        I am not blaming the pilots. They were a product of their training and airline culture. Seems a bit of a case of the children of the magenta.

        What *almost everyone* has missed was this mention in these comments is an *extremely important point*: AoA disagree was marked "where fitted"!!!

        This totally contradicts the "oh it should be there in all the planes, we just made a mistake" line from Boeing, if true!!

        Also initial reports I read said that this definitely was listed as an option, I am not clear on if it was to be included in the 50k AoA indicator or a separate option.

        Regarding simulators: Southwest contract with Boeing had a clause that if any sim training is required there is a penalty of 1M per airframe.

        Normalization of deviance - as so often.

        Regulatory capture.

        The real villains of this sad story can be found at higher levels of Boeing and at the FAA.

  27. Anonymous Coward
    Anonymous Coward

    If Boeing can't this shit right, what chance have we got of Renault et-al giving us safe driverless cars anytime soon? Hell, VW can't even give a straight answer on emissions cheating!

    1. Anonymous Coward
      Anonymous Coward

      Hell, VW can't even give a straight answer on emissions cheating!

      No, no, it did. It was a lie, of course, but it gave unequivocal answers until the truth could no longer be denied, which is why it was awarded rather unsubtle fines.

  28. Anonymous Coward
    Anonymous Coward

    "We continue to have utmost confidence in these aircraft."

    And the parliament have confidence in the government who have confidence in the PM.

  29. toffer99

    Killed by AI.

    Are these the first mass deaths caused by Artificial Intelligence? What could be the next major occurrence?

    1. Anonymous Coward
      Anonymous Coward

      Re: Killed by AI.


    2. Anonymous Coward
      Anonymous Coward

      Re: Killed by AI.

      This was not AI this was NO-I

  30. Anonymous Coward
    Anonymous Coward

    The Boeing 737 History of "BAD PLANEs started years ago.

    Watched a repeat[ed] presentation of "Why Airplanes Crash" just today. The featured plane was a Boeing 737. That plane decided to nose-dive itself into the ground. 'Bout 250+ killed. By coincidence it was linked to a similar nose-dive crash years previously and that incident had never had the cause of that crash solved. But luck is sometimes with us. Seems other pilots reported a similar incident from which the pilots DID recover and survive. Further investigations reveal a rudder control valve with construction which would cause the situation. OOPS! OH well, redesign the valve and patch all the planes with the redesigned replacement.

    Copying from someone else's post: If I'm planning a trip and "if the plane is Boeing, I ain't going."

    As the recent incidents were documented it seems profit takes "preceDENSE".

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