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Software

New Flaw Discovered On Boeing 737 Max (cnn.com) 114

An anonymous reader quotes a report from CNN: A new flaw has been discovered in the computer system for the Boeing 737 Max that could push the plane downward, according to two sources familiar with the testing, an issue that is expected to further delay the aircraft's return to service. A series of simulator flights to test new software developed by Boeing revealed the flaw, according to one of the sources. The latest versions of Boeing's popular jet were grounded in March after two crashes -- Lion Air flight 610 and Ethiopian Airlines flight 302 -- that killed 346 people.

While the crashes remain under investigation, preliminary reports showed that a new stabilization system pushed both planes into steep nosedives from which the pilots could not recover. The issue is known in aviation vernacular as runaway stabilizer trim. In simulator tests, government pilots discovered that a microprocessor failure could push the nose of the plane toward the ground. It is not known whether the microprocessor played a role in either crash. When testing the potential failure of the microprocessor in the simulators, "it was difficult for the test pilots to recover in a matter of seconds," one of the sources said. "And if you can't recover in a matter of seconds, that's an unreasonable risk." Boeing engineers are now trying to address the issue, which has led to another delay in recertifying the 737 Max.

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New Flaw Discovered On Boeing 737 Max

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  • Will Boeing survive? (Score:4, Interesting)

    by Anonymous Coward on Wednesday June 26, 2019 @05:08PM (#58830950)

    I see bankruptcy in their future. The lawsuits are starting to hit, and they had a months long spell with NO new orders, a highly unusual situation for a major a/c maker. The business they would have normally had is going to Airbus now, which re-designed their new planes from scratch to avoid the kind of problems Boeing faces.

    I can't see Boeing surviving this without a bailout.

    • by uncqual ( 836337 ) on Wednesday June 26, 2019 @05:56PM (#58831218)

      Nope. They will survive this - it will cost them some money but Boeing can handle it.

      They have a large backlog of orders and a couple weeks ago got an order for 200 more 737 MAX planes. Yes, it's hard to sell planes when they are grounded. Of course, any orders placed now won't be delivered until long after the 737 MAX is back in the air, but airlines feel there's no reason to rush to get their orders in the queue because other airlines are not chomping at the bit to jump in front of them so why not sit back and maybe get a better deal if Boeing becomes more eager to negotiate to as their order book slims down a bit.

      Airlines can't just switch to Airbus like you can switch from Pepsi to Coke. Training, capital costs, maintenance, spares, etc. make it very costly.

      And airlines know that, sure as the sun comes up in the East and sets in the West, the next problem might be with Airbus so switching doesn't guarantee protection from a similar grounding of an Airbus model.

      Of course, if you really believe what you wrote, you would have shorted Boeing stock with every resource you can muster. Have you?

      Airlines do not want to see Boeing OR Airbus to fail as that would leave only one supplier and airlines would lose much of their negotiating power. And, actually, neither Boeing or Airbus want to see the other fail -- they both know that whatever additional profits they could extract in the short term by a virtual monopoly would be offset either by government regulators or just by upward creeping prices caused by a monopoly would reduce the total industry wide sales in the next 20 years.

      • by aaarrrgggh ( 9205 ) on Wednesday June 26, 2019 @10:19PM (#58832468)

        While I agree Boeing will be fine in a few years, this is going to be a significant hit. The grounding will not likely be lifted before November now, and needing hardware upgrades for all delivered planes will take time. And the real gotcha is they have (or will soon have) more undelivered frames in storage than delivered aircraft. That is a lot of capital sitting in the desert, and a lot of time and energy to get the planes to a deliverable condition. Tesla’s “delivery hell” will look like a walk in the park.

        • There have been airliners with far more checkered histories and far greater designer flaws that still went on to be successful. The issue will be fixed. Boeing will lose some money. There will be lawsuits. Some employees and regulators will be sacked and we may even see criminal cases. But Boeing and the 737 aren't going anywhere.

          Don't believe me? Looks up the DC-9 sometime. It has killed over 3500 people yet was still one of the major workhorses of the world's airlines for decades. Technically its still fe

      • What Boeing received was a letter of intent, not an order.

      • by mjwx ( 966435 )

        Nope. They will survive this - it will cost them some money but Boeing can handle it.

        They have a large backlog of orders and a couple weeks ago got an order for 200 more 737 MAX planes. Yes, it's hard to sell planes when they are grounded. Of course, any orders placed now won't be delivered until long after the 737 MAX is back in the air, but airlines feel there's no reason to rush to get their orders in the queue because other airlines are not chomping at the bit to jump in front of them so why not sit back and maybe get a better deal if Boeing becomes more eager to negotiate to as their order book slims down a bit.

        Sure Boeing'll survive, but at what cost?

        IAG didn't sign an order for 200 737's, they signed a letter of intent. For the first time in decades Boeing has had to promise build slots without any money down. IAG could tear up the agreement tomorrow and have no losses from it what so ever. That is how desperate Boeing is, 200 build slots with not a penny deposit... or even a firm order.

        Airlines can't just switch to Airbus like you can switch from Pepsi to Coke. Training, capital costs, maintenance, spares, etc. make it very costly.

        True, but this is why Boeing is going to try everything before actually fixing the 737 MAX. In order to keep the type certif

    • by jrumney ( 197329 ) on Wednesday June 26, 2019 @06:44PM (#58831512)
      Airbus haven't redesigned any planes from scratch lately to compete with 737. The A320 series has the advantage of being newer (1980's rather than 1960's) so they were already designed at the start to accommodate bigger engines under the wings, and haven't reached the point yet where they need to push all the extra components to the side as on the 737-NG series, or push the engines forward and up (upsetting the balance under power) as on the 737-MAX series. The A320neo is to the A320 as 737-MAX was to the 737 - a more efficient engine and some aerodynamic and cosmetic changes, but basically the same airframe. The A220, which is chipping away at some of the 737/A320 market, was designed by Bombadier to fill a gap between the smaller Bombadier/Embraer/, who partnered with Airbus for manufacturing when their orders exceeded their production capacity.
      • by mjwx ( 966435 )

        Airbus haven't redesigned any planes from scratch lately to compete with 737. The A320 series has the advantage of being newer (1980's rather than 1960's) so they were already designed at the start to accommodate bigger engines under the wings, and haven't reached the point yet where they need to push all the extra components to the side as on the 737-NG series, or push the engines forward and up (upsetting the balance under power) as on the 737-MAX series. The A320neo is to the A320 as 737-MAX was to the 737 - a more efficient engine and some aerodynamic and cosmetic changes, but basically the same airframe. The A220, which is chipping away at some of the 737/A320 market, was designed by Bombadier to fill a gap between the smaller Bombadier/Embraer/, who partnered with Airbus for manufacturing when their orders exceeded their production capacity.

        This is the same problem as hatchbacks. Each successive generation of Ford Focus has gotten larger and lardier, so Ford had to introduce the Fiesta, a smaller hatchback about the same size as a Mk I Focus. With each generation the Fiesta has been getting larger and lardier so the Ford have had to introduce the Ka, which is about the same size as a MK I Fiesta...

        The 737 started out as a ~100 seat airliner in the 60's, grew to a 150 seat airliner with the Classic in the 80's when the A320 family was introd

        • by jabuzz ( 182671 )

          Eh, the Fiesta predates the Focus by over 20 years!!! Even the Ka predates the Focus. For factual information the Focus was introduced in 1998, the Fiesta in 1976, the Kia in 1996. I would also note that a Mk1 Fiesta was significantly larger than a Mk1 Ka.

          Of course this might change depending on which market you are located in. That is if you are in the USA your idea of a Mk1 Fiesta could well be significantly different from someone living in Europe, I can't be bothered to check but it is irrelevant to your

    • by Richard_at_work ( 517087 ) on Wednesday June 26, 2019 @06:47PM (#58831524)

      No, Airbus did not "redesign their new planes from scratch", they simply started with a newer design in the A320 family.

      The 737 was designed in an age where airports were not as automated as they are today - it was the dawn of the jet set age, and Boeing, along with its competitors of the day, was pitching its short range aircraft to airlines that did not want a heavily mechanised presence at all of its destinations to load and unload its aircraft. So the 737 was designed with a low undercarriage so baggage handlers could do all the work without significant mechanical assistance - the cargo doors were low to the ground, baggage was loaded by hand individually and not in bulk etc.

      The A320 was designed in the 1980s, when airports had significantly changed, and airlines were no longer afraid about having to have a mechanised presence at all destinations - therefor the A320 sits higher on its undercarriage, and can take standardised palletised cargo (including baggage), meaning its quicker to load and unload etc.

      And thats the root of the MAX's issue - it sits too low on its undercarriage for modern engines, and the cost of redesigning the centre wing box to accommodate higher undercarriage would add significant cost to the product, so it wasnt done.

      The A320NEO is not a new design, its a continuation of the 1980s A320 with updates, just like the 737MAX.

    • ...and they had a months long spell with NO new orders

      Good news for Boeing. "Boeing 737 Max: British Airways-owner IAG signs deal to buy 200 planes"
      18 June 2019 - BBC News

      BBC News Article [bbc.com]

    • they had a months long spell with NO new orders, a highly unusual situation for a major a/c maker.

      LOL Nope. While they have significantly smaller number of 737 MAX orders, they have a bunch of other models in production and in development. While the 737 MAX has fewer orders, others like the 737-700, 737-800, and 737-900 series continue to sell.

      Yes they took a hit to their stocks, but they still report string sales. Last year they had over 5000 737 MAX ordered, and that's the one with the problem, but they also reported over 2000 777's, 675 of the 737 models other than MAX (like the 737-700, 737-800, a

  • by Krishnoid ( 984597 ) on Wednesday June 26, 2019 @05:16PM (#58831010) Journal

    It seems like it's a popular seller. Are all of its problems or complaints to date software-related at the whole-plane control level?

    • by Anonymous Coward on Wednesday June 26, 2019 @05:22PM (#58831028)

      Other than that, how was the parade, Mrs Kennedy?

    • Re: (Score:2, Informative)

      by Anonymous Coward

      It's popular, because pilots with an existing 737 rating can fly it. It saves a lot on training for airlines that already have older variants of the 737.

    • by Anonymous Coward

      It's not a popular seller any more. Orders for them stopped after the second crash and the revelations about Boeing hiding critical systems from pilots, and they haven't received a single new MAX order since then.

      • Re: (Score:3, Informative)

        by uncqual ( 836337 )

        they haven't received a single new MAX order since then

        Except, of course, for this order [cnbc.com] for 200 737 MAX planes a couple weeks ago. I hope you didn't short the stock based on your ignorance (actually, I really don't care - a fool and their money are soon parted...)

        • by Anonymous Coward

          Nothing but a circle jerk. They aren't going to go thru with the plan.

          Per your source: ...signed a letter of intent at the Paris Air Show to order 200 Boeing 737 Max planes. Boeing wonâ(TM)t post the planes on its monthly order tally until the agreement is finalized.

        • by Anonymous Coward

          As noted elsewhere, it's NOT an order - but an intent to order in the future:

          > signed a letter of intent at the Paris Air Show to order 200 Boeing 737 Max planes. Boeing won’t post the planes on its monthly order tally until the agreement is finalized.

          They could absolutely change their minds and either just order 100, or order none at all. Truthfully, you don't publicly send a letter of intent if you're not serious about it, but you can bet that right now, IAG are haggling the shirt off the back of

  • by sonamchauhan ( 587356 ) <sonamc@NOsPam.gmail.com> on Wednesday June 26, 2019 @05:23PM (#58831034) Journal

    ... bad hardware can't be fixed by software. Start again. Redesign to be rid of MCAS.

    • by uncqual ( 836337 ) on Wednesday June 26, 2019 @06:04PM (#58831280)

      Nothing is wrong with the hardware. Many modern commercial aircraft with modern powerful engines will pitch up and require trim adjustments when increasing power. These planes are perfectly safe and no pilot questions that. The only reason for MCAS is to make the plane "handle" more like other models of 737s so a new type rating wasn't required.

      MCAS as initially designed, implemented, and documented obviously sucked -- but all of those issues appear to have been dealt with in the software upgrades (comparing AOA sensors, limiting the amount of trim MCAS will crank in being the biggest improvements). Yes, Boeing screwed up, but that doesn't mean the 737 MAX is inherently unsafe.

      • by Ecuador ( 740021 ) on Wednesday June 26, 2019 @09:30PM (#58832300) Homepage

        You are only partially correct. The NCAS can be "fixed" (as the news we are discussing says it is not yet correctly fixed) in the sense that it won't try to kill you, but give you a chance to disable it and gain control of the aircraft. Which means you will be then flying without MCAS.
        Can you see where I am going with this? If you are going to fly without MCAS at cases of emergency, you will need to be trained to fly without MCAS, which defeats the only reason the MCAS is there - just remove it.
        So I don't see how anything other than just removing MCAS would make sense. You can't possibly say the pilots don't need any training for the MCAS-off characteristics when turning it off is standard troubleshooting. You have to eat the cost of pilot training, but then just remove the damn thing and you have no problems (as long as everything else works - I can't say Boeing has all my trust right now, despite the great planes they had made in the past)

        • Re: (Score:2, Troll)

          by uncqual ( 836337 )

          Updates to training will be required that takes MCAS into account - I don't think there is any debate about that. Last I heard, Boeing and the FAA (and perhaps other national regulatory bodies) and pilot unions were discussing the form that this training should take. I think Boeing is still pushing for training that doesn't require simulator time but the pilot unions are objecting. For US, the FAA will eventually decide. That training may, however, not require a new type rating (which is what Boeing and the

        • This needs to be modded up. Some good sense here
        • When I'm on the highway, I use cruise control. If a bunch of idiots crowd me, I turn that off so I can change lanes, slow down, or otherwise evade them.

          The MCAS and other autopilot features are a lot like cruise control. They save the pilots from being over-worked on details that a computer can easily handle, so that when it comes time to deal with idiots on the "highway", they don't have a sore foot.

      • by vrt3 ( 62368 )

        > Many modern commercial aircraft with modern powerful engines will pitch up and require trim adjustments when increasing power.

        Why do people keep repeating that power-induced pitch up is the problem that MCAS is meant to solve? There is loads of information available by now, and still people appear to stay uninformed and, worse, spread that misinformation. Most or even all airliners have power-induced pitch-up tendency, and so does the MAX 737. But that has nothing to do with MCAS.

        MCAS is designed to co

      • by gweihir ( 88907 )

        Yes, Boeing screwed up, but that doesn't mean the 737 MAX is inherently unsafe.

        Actually, it does. Boeing screwed up to a degree that can only be explained by severe organizational defects and massively prioritizing profits over safety and all that with a big helping of incompetence on top. There will be more serious flaws in that design and the organization that caused these flaws is not fit to fix it.

    • by Richard_at_work ( 517087 ) on Wednesday June 26, 2019 @06:21PM (#58831378)

      They can't.

      Because a clean sheet (as that is what it would take) redesign would take 5 - 10 years, cost 5x that of the A320NEO family program, and as a result cede the entire upper segment of the narrow body aisle market (taking regional jets out of the equation) to Airbus for the foreseeable future.

      The MAX series was a reaction - Boeing was studying a 737NG replacement as a clean sheet design during the latter half of the 2000s, and was ready to make a decision on it when Airbus launched the A320NEO in 2010. Airbus then took 1,200 orders for the NEO in its first year of offering, and Boeing was left scrabbling for a response - Airbus was going to take the market.

      What *really* tipped the balance for Boeing however was American Airlines leaning toward taking the NEO over the 737 - American had been a staunch Boeing customer since the bad blood between American and Airbus over the Flight 587 incident, where American wanted Airbus to take full responsibility publicly for the crash, and Airbus refused (the NTSB criticised the lack of limiters on the Airbus A300s rudder controls, but placed full blame on Americans training and the actions of the pilot - the inputs the pilot made caused the rudder to fail well in excess of the limits required under certification). In the end, Boeing managed to salvage the American relationship and managed to get the order modified to "100 Airbus A320NEO family aircraft, and an option for 100 of Boeings next generation narrow body aircraft, whatever that may be"...

      Boeing needed something which could compete with the A320NEO, both in terms of airline economics and in terms of cost in development. As most efficiency gains come from better engines, Boeing was limited right there at that point to some form of variation on the 737NG - a clean sheet would have been significantly more expensive over the A320NEO that customers wouldn't want to pay the premium for a few minor percentage points better efficiency (as the engines wouldn't be much different to those on the A320NEO), and it would have taken significantly longer anyway (and Boeing was already way behind Airbus in terms of lead time at that point).

      So, the MAX is a product of the pressures that mounted to build it - it had to compete with the alternative on cost and availability.

      Of course, Airbus now has a fantastic problem to solve - the A320NEO's backlog is 10 years long, meaning thats a big negative against it in current sales battles. Airbus is ramping up A320NEO manufacturing capabilities to record levels, but it simply cannot halve that backlog period in the next 5 years, so here we are - a duopoly which usually works (both manufacturers do actually compete, the aircraft they produce are typically market driven and the best that can be produced at that point in time) but now is stuck where we have an inferior product on the market still selling unbelievably well simply because the alternative isnt available for the next 10 years.

      So no, Boeing cannot get rid of MCAS, they have to actually double down on it and do something they have been criticising Airbus for for 25 years - they have to bring more automation into the cockpit and take more direct control away from the crew, but they need to do it in a way which is manageable and correct this time. Airbus have done this since they launched the A320 in the 1980s, and Boeing have proudly claimed since then that their aircraft do not take control away from the pilots. Until now. When they did it in secret.

      The MCAS approach is a very much an attempt to introduce an Airbus-style envelope protection system to the 737, in direct contravention of Boeings claims over "pilot is in full control" and thats why they didn't tell anyone. Now they need to do it properly, in full view of the public and with no secrecy.

      • Airbus have done this since they launched the A320 in the 1980s, and Boeing have proudly claimed since then that their aircraft do not take control away from the pilots. Until now. When they did it in secret.

        The MCAS approach is a very much an attempt to introduce an Airbus-style envelope protection system to the 737, in direct contravention of Boeings claims over "pilot is in full control" and thats why they didn't tell anyone. Now they need to do it properly, in full view of the public and with no secr

        • by Anonymous Coward

          Airbus fans can totally badmouth boeing.

          Their fbw didn't cheap out on single sensors, be incredibly lenient on certification, etc.

      • They can't. [because business reasons]

        Well they can (or could have). Maybe they would have ceded control of a market segment for a while, but that is what happens in any industry when you don't have the right product at a particular point in time. I've no doubt that Boeing regarded the cost as unacceptable, but that is simply a reflection of considering profit more important than safety. Control of a market is not an inalienable right.

        • Yeah, you aren't understanding the scale of the market here - these are business decisions which are in the 50 year range, not something that they can suffer for a few years and get over. We are talking about tens of thousands of high value units sold within that period, not millions of widgets.

          You can hand wave and say that business reasons don't matter, but in this sort of market it's the difference between being a successful commercial aircraft manufacturer and leaving the market. Speak to Lockheed abo

          • Would it be so bad if Boeing just took out the MCAS and had the pilots get certified to fly the MAX without it? It would take longer to get all of the pilots certified but it would also regain people's faith in the plane again as they associate the problems with the MCAS. After all, the MCAS was put in to make the plane fly like the older versions of the 737. It's not required to make the plane airworthy.

          • I don't disagree with anything else you said. It was quite insightful/informative. I just don't agree on the criteria for "could have" (possible) vs "couldn't have" (impossible).

            They could have discounted the old design (to make up for the loss of efficiency to their customers) up until the point where it no longer viable on a marginal cost basis, while proceeding with a new design (which they could have started quite a while ago). They didn't have to wait until a competitor produced a more efficient aircra

      • by mjwx ( 966435 )

        They can't.

        Because a clean sheet (as that is what it would take) redesign would take 5 - 10 years, cost 5x that of the A320NEO family program, and as a result cede the entire upper segment of the narrow body aisle market (taking regional jets out of the equation) to Airbus for the foreseeable future.

        That really doesn't matter.

        Airbus couldn't hope to supply the entire upper segment of the narrowbody market... Its the biggest growth market in commercial aviation and Airbus is already at capacity. Boeing could put the original CFM56 engines back on and restart production of the NG with almost no ill effects apart from their pride. Single type airlines that standardised on the B737 like Southwest and Ryanair are not going to switch types even if the A320neo is a bit more efficient.

        Sure, Airbus blinds

    • bad hardware can't be fixed by software.

      ... said no chip designer in the last 10 - 15 years.

    • by wolfheart111 ( 2496796 ) on Wednesday June 26, 2019 @06:33PM (#58831464)
      Interesting, here's an article explaining it. https://theaircurrent.com/avia... [theaircurrent.com]
    • Re: (Score:2, Informative)

      by Anonymous Coward

      Oh come fucking on. Find me a software engineer working on low level stuff that never had to fix hardware problems in software. Not everything can be fixed but a lot of problems can and are fixed every day.

    • by gweihir ( 88907 )

      Wrong. That is not the problem here. The problem is that Boeing messed up the fix completely, in a way that can only be explained by a combination of extreme arrogance with extreme incompetence. They basically violated all the rules of design for safety-critical systems, and they did not tell the pilots what they had done. It is absolutely no surprise that this resulted in a lot of very dead people. But it could have been done right, and that is why I think Boeing is at the very least guilty of criminally n

    • Comment removed based on user account deletion
  • by Anonymous Coward

    (1) Get rid of the software/hardware that try to push it downwards to mimic traditional 737 characteristics.
    (2) Force pilots to recertify/train to fly new plane.

    • by Nidi62 ( 1525137 )

      (1) Get rid of the software/hardware that try to push it downwards to mimic traditional 737 characteristics.
      (2) Force pilots to recertify/train to fly new plane.

      Treat it like the A330/350 or the 757/767-400. Of those two pairs, the aircraft are significantly similar enough that pilots moving between the 2 only need a couple days of simulator training to be qualified on the new aircraft. Of course, that would throw a little bit of a wrench into Southwest's operations model as that company is specifically designed to operate 1 aircraft type, and adding in another type would greatly complicate things-bidding for pilots, scheduling pilots/recovering open flights/equi

    • Recertification as a brand new model will take between 2 and 3 years, and theres a chance that the 737 would fail to gain such certification anyway as it would lose the ability to grandfather in aspects of its design which would be disallowed under modern certification rules (I cant think of any off the top of my head, but I can guarantee that they exist - as a side note, the 747 wouldnt be certifiable today due to its placements of its front passenger doors). Recertification would also take significantly

    • That would require a whole new plane due to grandfathered components. The plane would be fly by wire. It would essentially be the same as the A320NEO, and would arrive in 10 years. In the interim, Boeing could only sell regional jets from Embraer for the narrowbody segment.

  • by kackle ( 910159 ) on Wednesday June 26, 2019 @05:38PM (#58831118)
    You can still see the ghosts
    But you can't see the sense
    Why they let the monkey go
    And blamed the monkey wrench

    "Rockin' at the T-Dance" [youtube.com] - The Rainmakers
  • In before Boeing representative declares this to be a new 'rapid descent feature'. It seems PR firms are everywhere these days...
  • by Anonymous Coward

    One thing to keep in mind with all these stories about the MCAS: MCAS does its work by adjusting the horizontal stabilizer trim.

    Horizontal stabilizer trim is much more powerful than yoke-elevator input, as it's adjusting the angle of attack of the entire horizontal stabilizer (the horizontal bit of the tail), rather than just the control surface on the trailing edge. Stabilizer trim is as fundamental of an input as the yoke, rudder pedals, throttle, or flap settings.

    The trim wheels are pie-plate sized thin

    • Yes, Boeing's design of MCAS has MAJOR flaws. They expanded its operational window without proper re-analysis. But in each of these cases the plane went down because the pilot also failed to intervene on a runaway stabilizer condition.

      Precisely, although I said the same thing a few weeks ago, and got modded -1 Troll very quickly. This is an emintly soluble problem, and follow the first law of aviation safety - first, *fly the airplane" .When MCAS is gone or the authority lim

      • And when you are in a dive even though you are fully pulling back on the yoke and the trim wheels won't turn and you have never heard of MCAS or the roller coaster maneuver and you are only a few thousand feet from the terrain what would you do? Genuinely curious.

    • Why do you think averaging would be a better solution ? It would give the flying pilot half authority on the controls as soon as the other sidestick is slightly moved off its neutral position.
    • You can flip a switch to disable the electric trim (that you are well trained on) to stop the computer from being allowed to move them.

      That is only true up to the Max. It was true on the NG for instance. They changed it in the Max so that there is no way to only turn off the flight computer's trim input by itself. You must also turn off the electric motor. You are also ignoring that the trim wheels cannot be turned at high speed when you do turn the motor off. So you have to somehow manage to slow down even when the plane is already in a dive or you have to do the roller coaster maneuver which I cannot help notice that you haven't mentione

  • by bobbied ( 2522392 ) on Wednesday June 26, 2019 @06:07PM (#58831294)

    Color me dubious about how CNN is reporting this. I don't think this is some "newly discovered flaw" but a well understood failure mode they happen to be testing as they go though all the fault trees again while recertifying the aircraft.

    There are all sorts of microprocessors, many attached to the stabilizer trim controls that do all sorts of things; the auto pilot does this to maintain altitude and/or rate of climb, there is a flight computer that makes changes based on things like extending the flaps or putting the wheels down which cause fairly large changes in pitch trim settings. All these are microprocessors doing stuff based on the software running on them and all of them could do BAD stuff if the microprocessor fails. This isn't some new and unique flaw they found in some microprocessor... We all know microprocessors have failure modes, that they stop working and can do bad things when they do...

    Plus, there are THREE authors on this CNN Story and "unnamed sources". Where the basis of this story may be true, I got a feeling that this is more about being at the top of the dog pile of negative stories about the MAX being filed than conveying actual information. All we *really* know is that they found some failure mode in the fault tree that they feel is taking too long for pilots to diagnose and work around and this fault has to something to do with a microprocessor.... The rest is pure speculation by the authors..

    • The only thing this story really says is that FAA pilots found that the plane went nose down when they simulated a CPU failure. The FAA should probably be a bit more specific if they don't want to be accused of covering for Boeing. EASA are already suspicious enough of the FAA rubber stamping and covering for Boeing. This is so vague it is hard to determine very much. Weird that they mentioned the possibility of replacing CPUs though. That would be scary if Boeing fucked up that badly. Hopefully this is jus

  • If you didn't notice this you are either too young, or too careless. Bugs were always there, this is not what I am talking about. What does happen is that a lot of conceptual errors are more and more present in modern software, starting with the classic "if" chains that cover only a part of possibilities (regardless of how they are actually implemented), to logical flaws in user interfaces, or outright mistaken assumptions that govern the software.

    There was only a matter of time before this problem affected

    • by Anonymous Coward

      It's not the programers but agile and product managers/product owners. And management demanding going for the 80/20. So even if the product owner writes acceptance criteria for all cases, logic only gets implemented for the 20% of the cases that 80% of the customers will encounter. The rest will either be struck down my the developers, or by management. That's why the product owners don't bother even writing acceptance criteria for edge cases any more.

    • by iTrawl ( 4142459 )

      Have the developers also fly the planes they program. All of a sudden the number of applicants will plummet and you'll get either Dunning-Krueger people who don't know they suck, or great people who know they don't suck because they can explain to you why they did what they did in every bit of code.

  • Comment removed based on user account deletion
  • "If builders built houses the way programmers built programs, the first woodpecker to come along would destroy civilization."

  • This should never have happened, but before it's certified again, it is going to get so thoroughly scrutinized and tested it will likely end up the safest thing in the air.
  • Thank you for posting this. Good reporting on this new problem! I am glad that I am not the software manager in charge of all this right now. That job must be worse than spending time in a federal minimum security prison!
    • From what I GATHER, the report that this is a NEW problem is false. When the 2nd accident occurred, I read and watched a bunch of reports. My understanding is that the automatic trim system / MCAS adjusts at one rate. The pilot's manual trim switch adjusts at about half that rate. In normal operation, it probably makes sense for the pilots normal electric trim rate to be modest. The FAA is unhappy that if MCAS triggers, that modest trim rate can take extra seconds to regain proper trim. This seems like

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