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Software Won’t Fix Boeing’s ‘Faulty’ Airframe

• weyman 8y ago
  I may be irrational but I’ll avoid the 737-MAX no mater what software they push.
  • kurthr 8y ago
    I guess I'll keep looking for my keys under the lamp post.
    • TheSpiceIsLife 8y ago
      I vaguely recall this being a reference to something. Would you mind elaborating.
      • function_seven 8y ago
        https://quoteinvestigator.com/2013/04/11/better-light/ https://quoteinvestigator.com/2013/04/11/better-light/
  • DuskStar 8y ago
    Really? My conclusion from this saga has basically been that the 737 Max is fine when flown by first-rate carriers (American, Southwest) and conversely that no plane is safe to fly with 3rd or 4th rate carriers in the third world (Lion Air). Everything comes down to the Swiss Cheese - you're focusing on Boeing's hole, while I care more about the stack of holes that Lion Air maintained.
    • CaptainZapp 8y ago
      Your theory falls flat on its face cosnidering that Ethiopian has quite a stellar safety record and a good reputation.
      • DuskStar 8y ago
        At the same time, Ethiopian flew a copilot with (IIRC) 200 hours of total flight experience. This changes emergency CRM from "one person flies the airplane, the other diagnoses the problem" to "Captain flies the airplane, babysits the newbie, and attempts to diagnose the problem". As for Ethiopian Airline's 'stellar safety record', comparing these two wikipedia pages [0] [1] they seem to have a similar (recent) safety record to Aeroflot. Yeah, Aeroflot's gotten better, but not that much better. (Ethiopian has two incidents that resulted in fatalities 2000-2018, discounting passenger hijackings - Aeroflot has one. Both have one "everyone on board" incident. And while I'm not sure about relative flight frequencies, Aeroflot has a fleet of 253 planes to Ethiopian's 112. For comparison, Delta has had 0 incidents resulting in fatalities since 2000 [2] on a fleet of 896. Same goes for United's fleet of 778 if you exclude hijackings - American (with a fleet of 962) had one non-hijacking incident in 2001) So I'm honestly not sure what people are talking about there. 0: https://en.wikipedia.org/wiki/Ethiopian_Airlines_accidents_and_incidents https://en.wikipedia.org/wiki/Ethiopian_Airlines_accidents_a... 1: https://en.wikipedia.org/wiki/Aeroflot_accidents_and_incidents https://en.wikipedia.org/wiki/Aeroflot_accidents_and_inciden... 2: https://en.wikipedia.org/wiki/Delta_Air_Lines#Accidents_and_incidents https://en.wikipedia.org/wiki/Delta_Air_Lines#Accidents_and_...
  • mscasts 8y ago
    Me too, I have booked a trip in the US this summer and I will check every flight in the US to not be of the MAX type. I don't think any trip are, but if they are I will not fly that one.
• CoolGuySteve 8y ago
  1) Like most people, I’m far from qualified to give aeronautical engineering advice, but as fly-by-wire technology gets more advanced, won’t this be the norm? ie: Airframes that are difficult to fly might always be more efficient, so have a computer do the hard part. 2) This part seems like the real damning misdesign: Boeing offered the single angle-of-attack sensor as standard equipment, and charged extra for a second along with a “disagree” indicator that would allow 737 MAX pilots to “cross-check” a faulty sensor. Citing those decisions, another observer noted: “Who would design a system with a single point of failure?”
  • wetpaws 8y ago
    >Who would design a system with a single point of failure? I guess we now have an answer to this question.
  • kalleboo 8y ago
    Re: 1, today I learned about this: > https://en.wikipedia.org/wiki/Relaxed_stability#Unstable_aircraft https://en.wikipedia.org/wiki/Relaxed_stability#Unstable_air... > Relaxed stability designs are not limited to military jets. The McDonnell Douglas MD-11 has a relaxed stability design which was implemented to save fuel. To ensure stability for safe flight, an LSAS (Longitudinal Stability Augmentation System) was introduced to compensate for the MD-11's rather short horizontal stabilizer and ensure that the aircraft would remain stable. However, there have been incidents in which the MD-11's relaxed stability caused an "inflight upset." > Updates to the software package made the airplane's handling characteristics in manual flight similar to those of the DC-10, despite a smaller tailplane to reduce drag and increase fuel efficiency. Maybe this isn't as new of a development as we think.
    • inferiorhuman 8y ago
      Maybe this isn't as new of a development as we think. Considering that McDonnell Douglas management is running Boeing these days…
  • kalleboo 8y ago
    > “Who would design a system with a single point of failure?” According to the original design, the MCAS was only supposed to adjust trim to a level that was easily overridden by the pilot essentially just pushing on the stick/adjusting the trim. If it had been implemented this way, sensor failure would not have been catastrophic and hence doesn't require redundancy. At some point this was either changed or implemented incorrectly so that MCAS had much more authority.
• w-ll 8y ago
  how `faulty` is the airframe compared to the F-35? I hear that needs massive amounts of sw to keep it balance.
  • kalleboo 8y ago
    Military aircraft have very different design goals from passenger aircraft.
  • TheSpiceIsLife 8y ago
    If I recall correctly the F-16 is also an unstable airframe dependant on software, yet arguably higly successful. Although the F-16 is from a different era. Perhaps we’re no longer capable of building complex systems?
    • TheSpiceIsLife 8y ago
      Further to my comment above, here's the line from the Wikipedia entry, which I vaguely recalled: The F-16 is the first production fighter aircraft intentionally designed to be slightly aerodynamically unstable, also known as "relaxed static stability" (RSS), to improve maneuverability. 1. The F-16 is the first production fighter aircraft intentionally designed to be slightly aerodynamically unstable, also known as "relaxed static stability" (RSS), to improve maneuverability.
    • Deestan 8y ago
      The F-16 requires specifically trained pilots to fly safely. The Boeing in question was flown by pilots who were not trained for or even made aware of significant modifications to the plane's behavior. A training wheel on a motorbike is not very hard to make well or drive with safely, but if you suddenly discover it during a sharp turn at speed, it's not going to go well.
  • mcv 8y ago
    Even the F-16 was controlled by software. I'm not sure if the F-16 was aerodynamically unstable, but some newer jet-fighters are, specifically for more maneuverability, and they rely on software to keep it flyable. However, those tend to be designed with redundant systems in order to avoid a single point of failure. Having a single poorly tested system rely on a single sensor to fix a fatal flaw in the airframe is the real issue, I think. But maybe a passenger plane shouldn't be designed to be unstable in the first place; it's not meant to be a jet-fighter.
• Luc 8y ago
  Well eetimes got some clicks, so job well done for the journalist who wrote this article about a blog post by some guy with experience flying large planes in a flight sim.
  • donedealomg 8y ago
    Welcome to the internet.
  • kevsim 8y ago
    So much for journalistic integrity. Might as well have just said “some guy on the internet”.
    • inferiorhuman 8y ago
      More accurate to say I've flown a 737 on my computer.
  • tlrobinson 8y ago
    Yeah but he’s an “instrument-rated pilot” (in his Cessna) /s
    • salawat 8y ago
      While they're is definitely a gap in the physical nature of controlling the two platforms, the fundamentals underlying both pieces of flying equipment are the same, and in most of the ways that really matter, there is no real difference between an MCAS like system on a Cessna vs a 737. [waits for the multi-engine and fundamentally different airframe crowds to die down] At the end of the day, strip out every system not at fault, and you have a pilot fighting a machine he isn't aware of the exact details of in terms of how it's response to various control inputs are translated to behavior of the plane. Any pilot period (and any honest Engineer) should be capable of recognizing the 737 and the MAX 8 are entirely different planes on a fundamental level. You may have made your comment in sarcasm, but it is kind of an Emperor's New Clothes situation going on for Boeing right now. When the laypeople can be quickly brought up to speed that something isn't fundamentally the same, yet you (the principal engineering firm) dig in your heels to insist it is, you've committed some grievous breach of public trust.
• manfredo 8y ago
  I've read a variety of articles on this and they often said somewhat different things. What I've been able to gather about the timeline of events is: 1. The new engines on the MAX shifted the center of gravity forward (and I assume center of lift stayed the same). 2. Boeing was worried that #1 would cause the plane to nose up during high angles of attack (so, take off and landing?), and added software, MCAS, to pitch up to counteract this. 3. There's some confusion over when this software kicks in and how to cancel it (something about the trim controls not cancelling MCAS?) 4. Regardless of #3, this software seems to have confused pilots and the current belief is that MCAS was active when pilots didn't want it active. 5. ???? 6. Planes crash. Also, I've read about some concerns about the fact that the handling behavior changed so much but the plane wasn't reclassified as a different type. I'm still unclear about how classifications plays into this story. My core point of confusion is, if MCAS is the culprit why isn't the solution to remove MCAS? Is tendency to pitch during high angles of attack unusual, and something pilots cannot be expected to counteract manually? I've only played sims like DCS and X-Plane (and not very much at that) but "nose goes up when I don't want it to, so I push stick forward" doesn't seem too complicated to me. Of course, I'm no pilot so I'm probably drastically oversimplifying the situation.
  • berkut 8y ago
    From what I've read, MCAS is disabled with the flaps down, so it wouldn't be for take-off and landing.
  • ritwikgupta 8y ago
    Wasn't the idea that they wanted to avoid pilot re-training? So if pilots would be expected to counteract manually, they would have to train to understand when to do that.
    • kalleboo 8y ago
      Pilots are already trained to handle runaway trim, the idea was that an MCAS failure would behave similarly and the same checklist they already trained on could be used. Due to issues in how MCAS was implemented however, the behavior was different from runaway trim and more confusing.
• kerng 8y ago
  Wondering if Boeing will be able to recover from this in regards to keeping the MAX flying at all. I mean, I will always pick a different plane from now on - just not a risk I'm willing to take in the foreseeable future. Not sure if my stance is common though.
  • Brakenshire 8y ago
    How easy is it for a consumer to make that choice? Is the information surfaced to consumers?
    • quickthrower2 8y ago
      Yes, you can find out which plane you are going to fly on. .
      • lexs 8y ago
        and airlines can change that plane at any time after you booked
    • kelnos 8y ago
      Many (most?) airlines list the aircraft type during the booking process. Even for those that don't, you can look up the flight number and date on a site like FlightAware or SeatGuru, which will tell you. But, if the airline needs to, they can swap out the scheduled aircraft for another one at any time up until takeoff. So you might book with the belief that you'll be on a 737 NG, but get to the airport and find (or not even notice) that you're on a 737 MAX.
    • codesforhugs 8y ago
      You can see it in most search engines, and after the Ethiopian crash Kayak announced they'll add an aircraft type filter. Other flight search engines will probably follow suit.
      • deleted 8y ago
        [deleted]
• chx 8y ago
  The big question is ... who will trust the Boeing - FAA duo after this? The 777X is coming, there surely will be rather pointed questions from airlines, the EASA and more.
  • akvadrako 8y ago
    There are just as trustworthy as any airline is now - making big mistakes like this is one of the best ways to change company culture.
  • rjf72 8y ago
    I think many do not understand typical practices of regulatory agencies. As a related example, what do you think the FDA requires in terms of genetically engineered foodstuffs? Many seem to think there's extensive oversight and safety testing. There isn't. They treat genetically engineered products and natural products identically. If a company has all their regulatory issues in order to market e.g. corn, they can cook up a new genetically engineered corn in the lab and bring it to market with literally 0 additional oversight necessary. All the FDA offers here is a completely voluntary consultation, and that in turn basically is little more than the company signing off on some checkboxes. This leads to a bemusing and disconcerting run around. Monsanto: "The Food and Drug Administration (FDA) is responsible for the safety and appropriate labeling of food and feed products grown from GM crops." [1] FDA: "It is the manufacturer's responsibility to ensure that the food products it offers for sale are safe and otherwise comply with applicable requirements." [2] Sound similar? It'll be the exact same story if/when a company inadvertently releases a harmful genetically engineered product. The assurance of safety provided by regulatory agencies is often illusory. As an aside, this is all clearly described on the FDA's page as well. [3] But the phrasing is designed to mislead consumers. They state repeatedly that it is unlawful to ship unsafe food to consumers without ever directly clarifying that they themselves never actually test the foods. Inventions go straight from Monsanto's lab to your plate. Obviously they have a major incentive to ensure their products are safe, but they have a long history of failing in that obligation yet remain a multi billion dollar company. [1] - https://monsanto.com/company/commitments/safety/statements/are-gmos-safe/ https://monsanto.com/company/commitments/safety/statements/a... [2] - https://health.usnews.com/health-news/health-wellness/articles/2013/04/25/gmos-a-breakthrough-or-breakdown-in-us-agriculture https://health.usnews.com/health-news/health-wellness/articl... [3] - https://www.fda.gov/Food/IngredientsPackagingLabeling/GEPlants/ucm461831.htm https://www.fda.gov/Food/IngredientsPackagingLabeling/GEPlan...
• cockatoo2 8y ago
  So many things wrong. Such a shitty product. Bad design, bad sensors, greedy incompetent management trying to make money from a basic safety system. Shut this shit down already.
• isquared23 8y ago
  This appears to be a thinly sourced article, based on a blog post opinion by someone who is a software developer and instrumented-rated (hobby?) pilot who has flown airliners in simulation only. With due respect, not sure whether that constitutes enough expertise to to qualify and opinion as news-worthy?
• cmurf 8y ago
  As an example of the seriousness of approach to stall, buffeting and proper recovery (you don't fall out of the sky like a rock, but recoveries take hundreds and possibly a couple thousand feet), this two year old serious incident in a 747 involving inadvertent stall while entering a hold, just had its final report issued. http://avherald.com/h?article=4a787699&opt=0 http://avherald.com/h?article=4a787699&opt=0
• isquared23 8y ago
  This article appears to be fairly thinly sourced. The one named source I can find appears to be a blog post by a fellow software developer who is an instrumented-rated pilot, however has flown airliners in simulation only. The article does not claim the source is a professional pilot or that they have ever flown the 737Max. With due respect, I am not sure whether that counts as enough expertise to qualify someone’s opinion as news worthy?
• cockatoo2 8y ago
  So who is flying in a 737 MAX when it comes back?
• rwhitman 8y ago
  The paper that this article cites is a far more interesting read than the summary: https://drive.google.com/file/d/1249KS8xtIDKb5SxgpeFI6AD-PSC6nFA5/view https://drive.google.com/file/d/1249KS8xtIDKb5SxgpeFI6AD-PSC...
  • sundvor 8y ago
    That's pretty awesome -- and chilling. His four seat Cessna's $20k avionics upgrade (which got automatic pitch regulation same as the Max) required more training and documentation than the multi-million 737 Max that killed 157 + 189 people. The 737 MAX is a dodgy design which probably ought to be banned.
  • SeaSeaRider 8y ago
    ... it’s written by a guy who uses flight simulators, this is crank stuff.
    • GregTravis 8y ago
      The 757 flight simulator that I've flown was a full-motion flight simulator at UPS's Louisville training facility. I was helping conduct 6-month certification flights as co-pilot. I would say that if those simulators are good enough for UPS's 757 pilots' recurring training, they're good enough for this Cessna driver to understand that difference between his plane and a 757. Answer: Not that much.
      • jordan_clark 8y ago
        Greg - Serious question - How is that air frame on the Max8 faulty due to engine placement when the A320NEO has almost the same design?
        • salawat 8y ago
          Because the A320neo can fit the engines under instead of in front of the wings, thereby negating the nacelles contribution to leading edge flow separation.
• trhway 8y ago
  today i first time saw the 737 MAX frontal view. Initially i thought that it was that typical funny plane-themed photoshop. I kid you not, it is the real thing - https://i.stack.imgur.com/GFzcj.jpg https://i.stack.imgur.com/GFzcj.jpg Just look at those nacelles. Deep breath. Look again. Take them in. Besides clearly visually screaming that this Frankenstein thing was quickly&cheaply slapped together and wasn't properly engineered and thus should just have never seen the light of the day, these nacelles obviously add more lift than normal symmetrical ones. So: 1. the engines placed more forward than pre-MAX 737 - that results in additional pitching up moment as the engines are below the centers of pressure, gravity, etc. 2. the engines are 2x higher-by-pass than pre-MAX 737 and thus the center of thrust is shifted even more forward and lower - as a result it adds even more of the pitching up 3. these asymmetrical nacelles generate more lift just due to the shape - and again due to the position of the engines that lift results in the additional pitching up moment. Basically that thing just can't really fly steady straight, and looking at all this some people at Boeing decided that a bandaid software patch would just fix it. Sounds like it were the same people who did the "curl" fix in today Cisco story https://news.ycombinator.com/item?id=19508472 https://news.ycombinator.com/item?id=19508472 :)
  • ihuk 8y ago
    I will not comment on (1) and (2) but (3) is wrong. I don't think that's even a 737 MAX on the picture. 737 was originally designed to be low to the ground to make it easier for ground crew to "bulk" load i.e. just throw stuff into the cargo area. The reason why 737 could be so low to the ground was that they were using turbojet[1] engines. Turbojet engines are very slim compared to new turbofan engines used on later 737 generations. When they moved to turbofan engines which have bigger diameter they needed to move them higher up from the ground. So they moved the engines in front of the wings. To gain even more ground clearance they moved accessory gearbox and fuel pump from underneath the engine to the side. That's why engine appears flat on the bottom. Obviously the engine is still round because the fan is round but the lip is flattened. All this allowed Boing to fit more efficient and quieter engines to 737 without extending landing gear. The shape itself does not generate much aerodynamical lift if any. On the 737 MAX they actually extended the landing gear and it does not feature "flattened" engine shape any more. [1] https://en.wikipedia.org/wiki/Pratt_%26_Whitney_JT8D https://en.wikipedia.org/wiki/Pratt_%26_Whitney_JT8D
• mhandley 8y ago
  Boeing's software fix, announced today, is to compare readings from both angle-of-attack sensors and disable MCAS if they disagree significantly. The obvious question is why they didn't do this in the first place? One possibility is incompetence. But Boeing engineers are smart people, so I'm not convinced by this. The elephant in the room is the requirement to maintain a common type rating with older 737 models. Suppose they did originally do what the fixed software does now, and disable MCAS if the AoA sensors disagree. The problem Boeing face is that with MCAS disabled when this occurs, the plane no longer flies like an older 737. They'd need to announce to the pilots an AoA disagree, and announce that MCAS was disabled. Now what? A pilot certified and trained on the older 737 would not know how the Max now differs from what they trained on. If they'd done this, they'd have needed to provide additional training, and this must have concerned Boeing management that it might jeopardize the common type rating. Hence it seems likely they didn't add the AoA sensor comparison for this reason, reasoning that it was unlikely to be a problem anyway. We now know that reasoning was flawed. What does this mean going forwards? Will EASA and other CAAs refuse to certify the modified 737 Max under the same type rating as the older 737? This certainly seems possible. If they did require a separate type rating, this would likely kill 737 sales, regardless of whether the plane is now safe.
  • siwatanejo 8y ago
    IIRC the two planes that crashed only had a single AOA sensor (the 2nd redundant one being only present in a premium add-on that those airlines didn't purchase), so this software fix would have not changed anything. EDIT: alright thanks for the replies.
    • acqq 8y ago
      > the 2nd redundant one No, it was never redundant, in the "premium variant" only the "they don't match" signal would be displayed / sounded, but only one used still, and the pilots would have to turn MCAS off and fly with the plane which behaves differently than the one for which they are trained.
    • mhandley 8y ago
      No, all 737s have two AoA sensors. The one on the captain's side feeds the flight control computer on that side, and the one on the first officer's side feeds the flight control computer on that side. At any one time, one computer is in charge. They can compare data, but Boeing decided not to for MCAS.
• jacquesm 8y ago
  You can't really fix any hardware fault in software. The best you can do is a workaround, but the whole will never be as solid as a properly designed system would be.
  • jillesvangurp 8y ago
    My bet is that Boeing will spend some time banging on this and then the 737 goes back to being a money maker for them for years to come. I'm guessing that at this point they know what is the problem and are probably pretty far done with coming up with many solutions and picking one that gets the job done. The way this works is that they have to do something because they are grounded. This may or may not involve installing some extra hardware but it will most certainly involve a software update.
• kchoudhu 8y ago
  This doesn't sound right: aren't unstable airframes controlled by computers the norm now? If that is the case, a software fix is the answer. If unstable airframes are not the norm, then the question we need to be asking is how the regulatory regime let an unstable airframe into service.
  • neuronic 8y ago
    If you want to fly from Germany to the Canarian Islands for 50 EUR round trip then you're going to end up with unstable airframes. The 737 MAX is in part unstable due to repositioned engines. They are larger and thus significantly more fuel efficient, however they would not keep enough ground clearance if they were positioned the same way as on the 737-NG. MCAS corrects for the repositioning, otherwise the plane may start to climb which in turn could lead to a stall.
    • jlangenauer 8y ago
      > If you want to fly from Germany to the Canarian Islands for 50 EUR round trip then you're going to end up with unstable airframes. How does B follow from A? That's quite the non-sequitur.
      • neuronic 8y ago
        B follows from A because in part A makes B economically possible. Reductions in fuel consumption factor greatly into ticket prices. It's easy to reduce services (luggage, refreshments, leg space) but reducing fuel consumption is entirely up to the aircraft manufacturers.
        • usrusr 8y ago
          But you don't need instability to get fuel economy, all you need is an airframe that actually matches the current engines instead of a relic from the 1960ies that was designed for tiny inefficient low-bypass engines. A plane designed for the new engines could be perfectly benign without sacrificing efficiency. Even a more properly adapted 737 that had the changes required to solve the problems aerodynamically instead could be fuel efficient.
• OJFord 8y ago
  What causes such inaccurate AoA readings? 'Vanes' freezing? From what I understand MCAS is about pointing up/down, so although AoA can of course be a more sophisticated angle in 3D space, couldn't the measurement for MCAS purposes be accomplished with a sensor based on gravity that could be entirely internal to the aircraft and so perhaps more reliable?
  • zamfi 8y ago
    There’s no real way to measure “gravity” in a plane, unfortunately. AoA is about airflow directions anyway, so wind angle plays a role too, beyond just plane angle to the ground.
    • OJFord 8y ago
      Suspended mass inside container fixed to plane structure, measure angle of mass relative to container? > AoA is about airflow directions anyway, so wind angle plays a role too, beyond just plane angle to the ground. That doesn't sound desirable though, is it?
      • zamfi 8y ago
        > Suspended mass inside container fixed to plane structure, measure angle of mass relative to container? Unfortunately not! This measures acceleration of the airframe, not gravity. Was a huge challenge in the early days of flight, and there’s a great history online that I can’t find right now. Anyway, this might be useful reading: https://en.wikipedia.org/wiki/Attitude_indicator https://en.wikipedia.org/wiki/Attitude_indicator > That doesn't sound desirable though, is it? Given that wing-angle-to-airflow is what matters when it comes to stalls, I’d say it’s eminently desirable?
      • peteradio 8y ago
        That is how lift is created. Air currents are not consistent over the plane. Sometimes they could more downward which would require a pitch up of the wings to catch and create lift. This is not the same as perpendicular to gravity which is easily measured in the plane. This is an entirely different animal.
• novaRom 8y ago
  >> “By laziness, I mean that less and less thought is being given to getting a design correct, and simple – up-front,” he wrote. Competitors have more less expensive engineering resources. You simply cannot produce high-quality, safe, stable complex systems in shorter time if you have limited human-engineering very expensive resources. This is not only related to aircraft-manufacturing.
• SeaSeaRider 8y ago
  There is a debate to be had, but this is a naked propeganda piece. The crux of the article is based on: “Among Boeing’s critics is Gregory Travis, a veteran software engineer and experienced, instrument-rated pilot who has flown aircraft simulators as large as the Boeing 757.” ... someone who uses flight simulators. This is not credible journalism.
  • mschuster91 8y ago
    > ... someone who uses flight simulators. This is not credible journalism. When talking about "instrument-rated", this most likely means a real rating certification. As for the flight simulators, best class "Full Flight Simulators" actually allow for zero "real" flight time for type rating transfers, as well as being actually used for the required regular training of airline pilots (per https://en.wikipedia.org/wiki/Full_flight_simulator https://en.wikipedia.org/wiki/Full_flight_simulator)
    • inferiorhuman 8y ago
      When talking about "instrument-rated", this most likely means a real rating certification. It is a real thing, but he's not type rated on a 737 and it shows. He and eetimes get a number of things plainly wrong. The article was mostly content-free clickbait and I'd encourage you to simply flag it.
      • ackfoo 8y ago
        Hatchet. Job. An article written by a non-pilot about an article by a GA pilot with no experience as an ATP. The elephant in the room is not the type-rating issue so much as the speculative cause of the crashes: if your aircraft is out-of-trim and control pressure cannot restore it, you have a runaway trim condition and you need to disable the electric trim system immediately. If, in these cases, it turns out that the AOA sensor was faulty, that is only one of many possible causes for a runaway trim condition. The core problem is not the specific cause, but the failure of pilots to respond appropriately to a common and easily-remedied situation.
  • 8y ago
• novaRom 8y ago
  Everything made in US has become extremely expensive. As a product manufacturer you have to pay a lot more than your Asian competitors. You can open an R&D subsidiary in Asia to reduce costs, but in very short time you will see your technology has diffused and now you have even more pressure from competitors. More bugs and design faults. Growth, innovation, effectiveness, all in a shorter time. All with increasing costs. And even more complexity, and more pressure. iCloud leaks, empty root password, reboot by WhatsApp message, Meltdown, Spectre, 737 MAX, etc.
• mosselman 8y ago
  I find the concept of fixing an airplane's hardware issues with a software fix incredibly scary.
• qwertox 8y ago
  It would be interesting if these kind of companies (aviation, car companies) were forced to publicly disclose the patch they are applying in order to fix a broken piece software. Maybe then they'd be more careful because of the extra scrutiny and the potential leaking of secrets. On the other hand, maybe then they'd patch as little as possible, although in this case, if a second patch would be required, a very hefty fine could be forced onto the company, or possibly force a full disclosure of all the relevant source code. Maybe the Blockchain could be used for some accountability here, where hashes of the blobs of all the software in the system, including the secret one, could be used as a means to prove that only a specific section of a codebase has been altered.
• csours 8y ago
  This reminds me of The Slow Winter by James Mickens [0] > "John was terrified by the collapse of the parallelism bubble, and he quickly discarded his plans for a 743-core processor that was dubbed The Hydra of Destiny and whose abstract Platonic ideal was briefly the third-best chess player in Gary, Indiana. Clutching a bottle of whiskey in one hand and a shotgun in the other, John scoured the research literature for ideas that might save his dreams of infinite scaling. He discovered several papers that described software-assisted hardware recovery. The basic idea was simple: if hardware suffers more transient failures as it gets smaller, why not allow software to detect erroneous computations and re-execute them? This idea seemed promising until John realized THAT IT WAS THE WORST IDEA EVER. Modern software barely works when the hardware is correct, so relying on software to correct hardware errors is like asking Godzilla to prevent Mega-Godzilla from terrorizing Japan. THIS DOES NOT LEAD TO RISING PROPERTY VALUES IN TOKYO. It’s better to stop scaling your transistors and avoid playing with monsters in the first place, instead of devising an elaborate series of monster checks-and-balances and then hoping that the monsters don’t do what monsters are always going to do because if they didn’t do those things, they’d be called dandelions or puppy hugs." 0: http://scholar.harvard.edu/files/mickens/files/theslowwinter.pdf http://scholar.harvard.edu/files/mickens/files/theslowwinter...
  • ixtli 8y ago
    This is wonderful.
  • songeater 8y ago
    this is awesome and probably needs a thread of its own
    • csours 8y ago
      There have been a few, but it looks like none of them really sparked a lot of discussion: https://hn.algolia.com/?query=Slow%20Winter&sort=byPopularity&prefix&page=0&dateRange=all&type=story https://hn.algolia.com/?query=Slow%20Winter&sort=byPopularit... --- I've submitted it again: https://news.ycombinator.com/item?id=19514259 https://news.ycombinator.com/item?id=19514259
  • 8y ago
• sudoaza 8y ago
  If the cost of the recertification is more than the expected profits, we don't do one
• not4noob 8y ago
  Somewhat off-topic but this has been bothering me: Several years ago I was in a program review and ended up in an argument with the lead Boeing software QA person for a particular group. The disagreement was because the person made a blanket statement that their QA process ensures there are no defects in their flight software. My response was that such a statement is absurd and that all software beyond some minimal complexity has defects. (A statement that I still agree with even though it is hyperbolic.) None of this has any direct relationship to the 737 Max issues as this wasn't even an airplane program but I think it points to what might be a cultural flaw if this attitude is widespread.
  • alkonaut 8y ago
    > ensures there are no defects in their flight software. "Testing only proves the presence of defects, not the absence" However, I think you are talking past each other here. The person you taled to was likely defining "no defects" to mean "all 1000 boxes ticked on the spec/testing protocol". They should call it "known defects".
• RenRav 8y ago
  you can only make so many systems redundant before the weight increase and lower capacity outweighs any potential risk of systems failing, or this is how it seemed to me when i compared cargo carriers to other aircraft. you need constant dedicated maintenance and regular troubleshooting, i don't understand how more ptoblems like this haven't already occured. there is only so much you can do without a reliable pilot to disable anything causing problems. and having seen firsthand the problem solving methods and goto solutions for maintainers, everytime a plane lands successfully it's a miracle
• ggm 8y ago
  The source article is attracting some heat. But, this aside, does anyone else think the meta-questions about the FAA and their relationship to Boeing, and the 'same type' certification process begs questions? I "get" that people wanted this. But a regulator has to ask a subtly different question: is this actually in the wider public interest which is not neccessarily what Boeing wants.
• sagebird 8y ago
  Why does an active MCAS system need to exist in order to tamp down on pitch up? I wonder if modifying the surface of the wing and or tail could achieve this. Eg, make a computer model of the plane, verify that it captures the real pitch up behavior, and “evolve” a wing that counteracts it. I suppose the hard part is that we are searching for a perhaps complicated non-linear response, that needs to behave differently across speed, atmospheric conditions, pitch and turning. But maybe there are enough degrees of freedom when evolving a surface that it can capture it all?
• alkonaut 8y ago
  What if it doesn't? I can see two ways in which they risk ending up with "major" problems - They need to make changes that means it's no longer a 737 for certification. - They need to make changes that delay production and even mean recalls of built plane, say moving engines rearward which in turn would mean big airframe/landing gear changes to manage ground clearance. These would be very expensive, cause tons of cancelled orders, and possibly also cause the same issue with certification as the above. Any of those chnages would maybe kill the whole MAX program. And that would leave Boeing without a competitive plane in the most common class? Is this a possibility?
• z5h 8y ago
  What's this about "engineering incompetence", "engineering ethics" and "“cultural laziness” within the software development community"? Do we have any reason not to believe that management is at fault? That management forced engineering to do things quicker/cheaper and cut corners and hack out a solution in those interests?
  • slavik81 8y ago
    Management pressure is not an excuse for faulty engineering. As an engineer, your first duty is to the public, then your client, then your employer. That's straight out of the engineering ethics handbook. Your boss comes third. When you sign-off on a design, it is your approval. Your name goes on the document. There's no passing that off as someone else's fault. If you are unable or unwilling to say "no" to your employer, then you do not meet the criteria to be a professional engineer. Your employer may find another engineer to sign-off, but perhaps that person will think on it carefully, knowing that someone else refused. If something later went wrong, it could not be passed off as a simple oversight.
  • salawat 8y ago
    While management is definitely culpable, aviation is not like most software development shops in that legally speaking, your engineers do have final say. If they don't sign, nothing ships. An engineer is expected to do more than acquiesce to management's demands. It is, in fact, an engineer's job to say "no" to any implementation plan that jeopardizes the public. There is a case to be made whether it is reasonable to expect an engineer to branch their scrutiny beyond what small slice they are given, in which case there was a failure at a higher level to distribute appropriate units of work such that the entire thing was thoroughly vetted. The problem is, that is extremely difficult to prove in a court of law, and it is not uncommon for high level management to hide unethical practices behind indirect communication methods without committing them outright to paper. Call me a romantic, but at some point, as a bunch of engineers on a project, you need to be able to fully grok and model the entirety of the system as a whole. It seems that level of integration would have brought these problems to light much faster, and without the bloodshed. I can't imagine that work not happening unless it was being actively discouraged. If one or several engineers had pushed back, or a manager been thinking more about product quality/safety rather than delivery/profit, that work may have been done, and we wouldn't be talking about this now.
• fixermark 8y ago
  It's odd to call the airframe "faulty" when (a) it flies and (b) the FAA requirements for positive static stability in the airframe itself don't forbid the 737 MAX from being flown. Does the author mean the FAA airframe acceptance criteria are faulty?
• jcims 8y ago
  Seems more like a faulty plan than a faulty plane.
• ycombonator 8y ago
  The author mentions this engine in the article and there is a neat video of the behemoth engine. Pure mechanical engineering excellence ! https://www.youtube.com/watch?v=5CytG5M5Jcs https://www.youtube.com/watch?v=5CytG5M5Jcs
• mcguire 8y ago
  "Among Boeing’s critics is Gregory Travis, a veteran software engineer and experienced, instrument-rated pilot who has flown aircraft simulators as large as the Boeing 757." Ok, what? I'm a veteran software engineer and I've flown (MS) flight simulators such as the 747 (badly), and even I know that none of that gives me any grounds to weigh in on this situation.
  • txsoftwaredev 8y ago
    "instrument-rated pilot" - That's the key part that makes this individual able to weigh in on the situation.
    • mcguire 8y ago
      There are a lot of instrument-rated pilots; it's not a high bar (https://www.aopa.org/training-and-safety/active-pilots/ratings-and-endorsements/instrument-rating https://www.aopa.org/training-and-safety/active-pilots/ratin...). There are far too many people making pronouncements on this issue who have no business doing so.
• deleted 8y ago
  [deleted]
• GregTravis 8y ago
  Hello, This is Gregory Travis, who wrote the original article on which the EE Times article is based. If any of you have a specific question regarding my conclusions or how I got them or want to discuss any statements of fact, I'm more than happy to engage.
  • prolepunk 8y ago
    Thank you for your paper. It was a worthwhile read and it filled in a lot of details I didn't notice about the crash also affirming the criticism I hold of the process of software development -- where all of the decisions are deferred to the magical 'algorithms' without considering what who writes the algorithms and how decisions about them are made. The more persistent problem would be how artificial intelligence is used to increase 'engagement' while also fueling hate, and is an example of programmers and their managers not listening to social scientists and journalists. When planes goes down it's the case programmers and their managers don't listen to engineers and people on the ground.
  • rconti 8y ago
    Thanks for checking in, hopefully this gets the visibility it needs. (and sorry it's the eetimes article getting the publicity!) https://drive.google.com/file/d/1249KS8xtIDKb5SxgpeFI6AD-PSC6nFA5/view https://drive.google.com/file/d/1249KS8xtIDKb5SxgpeFI6AD-PSC...
  • mhb 8y ago
    Why is this: “once this thing pitches up, it wants to keep pitching up”? And why is it more of an issue with the engines in their new position? Thanks.
    • GregTravis 8y ago
      Couple of things here to keep in mind. First, when the A320 came out I wrote extensively about its fly by wire system, which was highly controversial at the time (early 1990s). It’s been nearly thirty years since then and long story short, Airbus has vastly more experience with implementing cockpit automation than Boeing. Boeing simply got in far over their expertise with deadly results Second, Airbus’ 320 airframe does not impose the same issues with larger engines that the 737 does. For starters, the 330 airframe started life in the era of large high-bypass turbofans — its initisl engines were much larger than the 737’s initisl engines
• l31g 8y ago
  This article is clearly clickbait. I don't think they've done a good investigative job. Even though I don't have any pilot license, I have flown "full" 747, 767, 777 and 787 simulators, but this doesn't give me the authority to make broad statements about an airframe being faulty or not.
• systemBuilder 8y ago
  I can't understand how a switch this simple could fail, frankly. Wouldn't a Mercury switch with an arc'ed path and several electrical contacts work? It seems blazing simple and idiot-proof. We are not being told the entire story! STAY TUNED!
  • kawfey 8y ago
    A mercury switch is probably not as reliable as a wind vane in high turbulence.
• ncmncm 8y ago
  The key failure of the MCAS system I have not seen discussed is that if it is overriden, and triggers again, it cranks the trim another notch. Trigger it five times, and each time it makes the plane less flyable. When Lion Air crashed, it had been triggered many times. Making MCAS pay attention to two sensors might help a bit, but the disaster is still latent. Once it trims, it should never trim again without a full reset back to baseline. There are standards relating to this sort of thing in flight assist, about how much "authority" an automated system may assert, in total, and they were ignored, apparently because they did not treat it as part of the autopilot system. If the standard had been observed, the bad sensor could not have had much effect on the flyability of the plane. The pilots would have needed to apply some force to keep the nose up, but would have succeeded, long enough to discover a fix or to turn around and land.