10 ms·

They say that most accidents are a sequence of several failures, but from what's in this article it sure seems to me like 100% Boeing's fault. If the only main

• JauntyHatAngle 8y ago
  Too early to say that, and it's still conjecture from what I can tell. Bad maintenance, and/or airline culture could still be a big part of the incident if it turns out there were warning signs ignored or bad repairs done. So I would still disagree that anything is conclusive and certainly not 100% Boeing's fault yet.
• danso 8y ago
  From my complete layperson perspective, this flawed-sensor/autopilot failure feels even more inexplicable than Tesla's Autopilot failing to stop for stationary objects. In the latter case, I can grasp how it's difficult -- or at least an open-ended problem to train a system to distinguish such objects in real time. But the heuristics for stable flight seem much more bound to hard-coded heuristics and physical facts -- isn't there a calculable, mostly-predictable limit -- for any given altitude -- to how much a plane can correct for a stall by nosediving. And when this limit is approached, shouldn't the plane's autopilot cede more control to the human pilot, if there's no indication that the pilot is otherwise incapacitated? But it sounds like there's still a lot of unknowns about sensor readings and chain of events -- for all we know, it's possible the plane made a reasonable auto-correction, but the pilots misinterpreted the sensor readings and inadvertently caused the plane to go into an uncontrollable dive. Given that this is the Boeing 737 Max 8's first major crash, and it happens to be with one of the most unsafe budget airlines, it seems premature to say Boeing is at 100% fault. OTOH, 1 crash/189 deaths of a new plane, of a model that has had just 2 years of service so far, is not a statistic that justifies giving Boeing the automatic benefit of the doubt. edit: Also, the Lion Air plane was said to have had the same major glitch with its airspeed indicator in all of its 4 final flights [0]. Even if Boeing's design is found to have shortcomings, Lion Air choosing to not ground the plane despite 4 consecutive flights of buggy behavior is a huge indictment of its safety culture. [0] https://www.popularmechanics.com/flight/airlines/a24568956/lion-air-flight-jh-160-red-flag/ https://www.popularmechanics.com/flight/airlines/a24568956/l...
  • rjvs 8y ago
    If the sensors are giving the software false altitude readings, how would your heuristics help?
    • village-idiot 8y ago
      There’s more than one sensor, expecting one to give bad readings is something that should be handled.
      • asdfasgasdgasdg 8y ago
        This is my question: why just one AoA sensor? It seems like there is plenty of space on the nose to put two or even four. Their results could be averaged. Presumably the MTBF for any individual AoA sensor is quite low (if we're happy to fly planes with just one right now), so this shouldn't cause too much of an increase in maintenance burden. I don't actually know how many AoA sensors there are, but the NYTimes article seems to refer to refer to them in the singular when talking about this plane.
        • village-idiot 8y ago
          Every article I’m reading says “AoA sensors”, which implies more than one. I think the flight computers did not correctly handle one of several sensors providing bad data.
  • skgoa 8y ago
    > isn't there a calculable, mostly-predictable limit -- for any given altitude -- to how much a plane can correct for a stall by nosediving. And when this limit is approached, shouldn't the plane's autopilot cede more control to the human pilot, if there's no indication that the pilot is otherwise incapacitated? There is, but there will always be a dependency on sensors to feed the input values into these funcitons. Modern flight computers are far better at pretty much any flying task than humans. Other than communicating wiht traffic control and raising/lowering the flaps and gear (none of which are absolutely necessary), a modern airliner can take off, cruise and land entirely on its own, with no human intervention. I agree that it's probably a combination of bad maintenance, a not quite perfectly fault-tolerant system design and human error of the pilots. One factor that hasn't been mentioned is that even the newest versions of the 737 contain ancient, obsolete technology. A newer airliner will probably have more redundant and more fault-tolerant systems.
• bsder 8y ago
  > If the only maintainence problem with this aircraft was a broken sensor, then that is almost irrelevant because sensors can break during flight too. It seems like none of the airplane manufacturers test what happens when sensors go AWOL. How many more crashes are we going to get because a stupid sensor malfunctioned before someone finally slaps some sense into Boeing and Airbus?
  • na85 8y ago
    Hi, I work in airworthiness. You should educate yourself on the facts because you are way out of your lane here.
  • VBprogrammer 8y ago
    Really? Aircraft crashes are staggeringly rare. For the most part they are caused by the pilots of those aircraft. I haven't read too much into it but I suspect this system was part of an envelope protection system designed to stop the pilots from being able to fly outside of the aircraft's performance limits. Once a fix is applied I'm sure this system will save many more aircraft than it harms.
    • tialaramex 8y ago
      Nitpick: Aircraft crashes aren't actually that rare, but Commercial Scheduled aircraft crashes are very rare. If you buy plane tickets you're far more likely to die driving to the airport than in a plane crash. But if your friend takes you for a fun trip in their Cessna that's a different story. General Aviation is dangerous the same way private automobiles are dangerous. The operators take silly risks, they lack advanced skills, corners are cut on maintenance, procedures are not followed correctly. They usually have just one engine (if it fails this may be survivable but it's not good) one pilot (who doesn't need to be as fit and healthy as a commercial pilot, nor as well trained) and they aren't required to file a flight plan, which means they may not really even have a plan A let alone plan B.
      • VBprogrammer 8y ago
        I think it was clear I was talking about commercial aviation but to lend some balance to your post let me address some of the points. General aviation aircraft operate in completely different circumstances. Using shorter, sometime grass, runways without the benefits of instrument landing systems. Usually outside of the ATC system. The general aviation fleet is generally ageing. 30+ year old aircraft are not at all uncommon. They have one engine; however it is about 2 steps below a lawnmower in terms of mechanical complexity. So long as it receives a fair supply of fuel stoppages are very rare. I don't think you can make any connection between a lack of flight plan and the safety of a flight, other than perhaps that the search and rescue team might have a better chance of finding you if the worst happens. There are plenty of non-commercial pilots who aspire to a standard of piloting which are at or above the level of commercial pilots (consider display pilots). All in all, the level of safety in general aviation is roughly similar to that of riding a motorcycle.
• bsaul 8y ago
  From the article : Pilots and former safety regulators said that Lion Air flight and maintenance crews regularly filled out two log books, one real and one fake, to hide malfeasance. If that’s true, i wouldn’t quite call it 100% boeing.
  • bodas 8y ago
    Here we have an Indonesian company with a terrible safety record and an aircraft that hasn't been maintained properly. However, if the computer is found to have initiated the pitch downwards, then the same failure could happen to any aircraft of this type, even if well maintained, if the sensors or computer simply begin to malfunction while the plane is in the air. Absent pilot error, the worst that should happen is a reversion to manual control. What concerns me is that any software flaws with the aircraft will not be addressed until the problem reoccurs with another more reputable airline in the future, because Lion Air appear so guilty in this case.
    • raverbashing 8y ago
      I'm not sure how it works on that specific model, but it's usual that a disagreement between sensors doesn't trigger a direct action like pitch down. It will more likely trigger a 'fallback' action like turning autopilot off (or changing flight mode which is what happened on AF447)
      • VBprogrammer 8y ago
        It sounds like a trim runaway incident. This has been a known issue since the earliest days of electronic trim controls. For those who don't know, trim is the system by which the neutral position of an aircraft's controls is set. In this case in pitch. An aircraft will fly at more or less a fixed speed for a given trim setting, slowing down will cause it to pitch down unless a correcting force is applied to the controls, and speeding up will cause it to pitch up. The problem is that in a severe out of trim condition it can take tens of kilograms of force to maintain the desired pitch. Trim runaway is when the trim motor for whatever reason doesn't stop moving, in the simplest systems this is sometimes caused by faulty switches. Most aircraft actually have a switch which is split down the middle but is naturally pressed as if it were one. This requires two of the switches to fail to get this situation. There are usually trim in motion indicators and alarms if it's in motion for too long which are intended to help pilots avoid this situation. I suspect the computer drove the trim heavily nose down, as a result of the envelop protection trying to avoid a stall. The pilots probably tried to intervene or the autopilot handed them the aircraft back knowing something wasn't right. At that point the trim was mis-set enough that they failed to recover correctly. Mostly conjecture but it fits what I've read.
• deleted 8y ago
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• isoskeles 8y ago
  Is it Boeing or “someone at” Boeing?
• marcosdumay 8y ago
  From the article, the plane has had 2 reports of sensor malfunction by the time it took off. If it was as simple as "sensor is bad -> plane falls", it would had fallen much earlier.
• ken 8y ago
  "Boeing" is 100,000+ people, and many times more in contractors and subcontractors. As you say, there's redundancy and sanity checks. No one person is solely responsible for any system on a BCA aircraft. Blaming "Boeing" here is about like blaming "Microsoft" for a bug in a Microsoft product, or "NASA" for Apollo 13. All the problems may have taken place in a building with that name on the door, but it's still very far from a single point of failure.
  • yummypaint 8y ago
    The whole point of a corporation is to protect the liability of the individuals in the company. I would argue Boeing and Microsoft are the correct entities to blame. After all, if the people who actually fucked up aren't individually liable, and the organization as a whole isnt responsible, then who is?
• wsc981 8y ago
  100% Boeing's fault? I would disagree with you after reading the article. That plane should have never been allowed to fly after having problems for many days and without figuring out proper fixes. Perhaps Lion Air should have flown in some Boeing engineers to look at the plane.