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Prosecutors, Transportation Department Scrutinize Development of Boeing 737 Max
- x0x0 8y agoThe article didn't seem to mention this crucial detail [1]: The original approval was based on Boeing's claim the MCAS had a max control of 0.6 degrees of the 5 degrees possible. This later became 2.5 degrees applied repeatedly, so 5 degrees. The 0.6 claim meant that the MCAS system qualified for a max risk of hazardous (people injured), not not catastrophic (ie plane loss). FAA officials claim that: (1) the mcas shouldn't even have qualified as a hazardous risk, and (2) they were unaware that it could fully control tail deflection. There are at least three decision makers that are probably in trouble: whoever let the MCAS have a max rating of hazardous, whoever allowed the MCAS more control, and whoever didn't notify the FAA. Hopefully management rather than line-level engineers though, because this seems like a company failure. [1] https://www.seattletimes.com/business/boeing-aerospace/failed-certification-faa-missed-safety-issues-in-the-737-max-system-implicated-in-the-lion-air-crash/ https://www.seattletimes.com/business/boeing-aerospace/faile...
- zkms 8y ago> The 0.6 claim meant that the MCAS system qualified for a max risk of hazardous (people injured), not not catastrophic (ie plane loss). My god. So that is why they only used one AOA sensor rather than comparing both -- and offlining MCAS if they disagree -- they thought it was DAL C (maybe because 0.6 degrees of stab trim likely can be countered with elevator deflection) and not DAL A. And since there was no annunciator on the flight deck to indicate that MCAS was kicking in, the flight crew on the incident aircraft weren't able to diagnose the problem (since it didn't act like a traditional trim runaway) and do the appropriate actions to disable the electric trim control before it was too late. Horrific.
- noir_lord 8y agoFor a long time I've used a saying I originally got from a pilot (iirc), "It's not the first problem that gets you, it's the 2nd and 3rd". In this case it's looking more like a sequence of survivable problems in short order leads to aircraft loss, as you said, horrific.
- sokoloff 8y agoI completely agree for the LionAir crew. For Ethiopia, I can’t imagine any 737-Max crew could step into a cockpit not having the NNC for stab trim runaway, whether MCAS or not, reviewed and top of mind and have the idea of killing electric trim at the first hint of a trim issue.
- cjbprime 8y agoAs I understand it the copilot on Ethiopia had around 200 of flying total, in any plane. The copilot usually manages checklists. At 200 hours it was probably their first emergency.
- michaelt 8y agoStill, the Runaway Stabilizer memory item [1] has the pilot switch the stab trim cutout switches before moving on to the printed checklist. [1] "I. Runaway Stabilizer" on https://www.theairlinepilots.com/forumarchive/b737/b737memoryitems.php#i https://www.theairlinepilots.com/forumarchive/b737/b737memor...
- petee 8y agoIf annunciators are eventually mandated, I wonder if we'll ever see a situation where MCAS legitimately intervenes, and a pilot in a panic turns it off while approaching stall. Sounds far fetched, but this whole situation and how its been handled seriously undermines confidence in safety systems you shouldn't be worrying about in an emergency; and the right combination of issues certainly takes down planes, as seen with Lion Air
- oakmad 8y agoWell there's an option for dual AOA but neither Lion or Ethiopian took it. In the case of AOA disagreement a light illuminates. Source https://twitter.com/trevorsumner/status/1106934415610073091 https://twitter.com/trevorsumner/status/1106934415610073091 and https://theaircurrent.com/aviation-safety/southwest-airlines-is-adding-new-angle-of-attack-indicators-to-its-737-max-fleet/ https://theaircurrent.com/aviation-safety/southwest-airlines...
- cjbprime 8y agoThat's not quite accurate. The plane has dual AoA in either case. The option is for AoA indicators and disagreement light. So, the US airlines who bought the option will have a disagree light, but it's still the case that their MCAS is only being fed by one sensor, so they could experience the same control problems.
- oakmad 8y agoThat is true, here's a source https://qz.com/1574441/a-warning-signal-that-could-have-prevented-the-lion-air-crash-was-optional/ https://qz.com/1574441/a-warning-signal-that-could-have-prev... A pet peeve is people not sourcing corrections
- michaelt 8y agoMaybe it's because we're looking at the design with hindsight, but it seems strange to me that the AOA disagreement light would be an optional feature.
- kayfox 8y ago> And since there was no annunciator on the flight deck to indicate that MCAS was kicking in It is fairly clear when its trimming, theres a noisy wheel spinning on the pedestal between the pilots.
- LoSboccacc 8y agohttps://i.redd.it/m4yrvqi2d6oz.jpg https://i.redd.it/m4yrvqi2d6oz.jpg eh. if you're trained to look at it as a source of problem and primed by the flight log that it might be acting up, otherwise it's easy to overlook.
- kharms 8y agoFor anyone else curious about what DAL means: Design Assurance Levels (DAL) DAL A describes flight electronics hardware whose failure or malfunction could cause a catastrophic, hazardous, or severe condition that would result in the deaths of everyone aboard the aircraft. DAL B describes flight electronics hardware whose failure or malfunction could cause a severe or hazardous condition that could involve some loss of life. DAL C, meanwhile, describes hardware whose failure or malfunction would result in a major flight condition that likely will involve serious injuries. DAL D describes hardware whose failure or malfunction would result in a condition that causes only a minor non-life-threatening flight condition. DAL E, finally, describes hardware whose failure or malfunction would have no effect on the aircraft's operational capability or pilot workload. >https://www.militaryaerospace.com/articles/2016/11/safety-certifiable-design-assurance-levels-dal.html https://www.militaryaerospace.com/articles/2016/11/safety-ce...
- ajnin 8y ago> max risk of hazardous (people injured) Still, relying on a single sensor when failure could cause multiple injury is grossly negligent. I don't know what failure rates are mandated for this risk level but a single sensor probably doesn't meet that. When you coumpound that with the fact that they sold a "premium" redundant version of that system with proper alarms in case of disagreement between sensors, then it's not hard to conclude that they put their commercial interests first, and people's safety second.
- sschueller 8y agoSadly even if foul play is found at Boeing I doubt anyone will be held accountable. The Government is full of ex Boeing people even the Secretary of Defense is a 30 year Boeing vet.
- virgakwolfw 8y agoWhy is MCAS needed? If the MAX is so similar to old 737’s and no additional training is needed, then why the MCAS? The most relevant question is “is the MAX aerodynamically stable?” If it is, why do we need the MCAS? That needs to be investigated. If plane at a low altitude at full power is stalling, just lower the nose. That is pilot training 101. Why need a system like MCAS to help. The pilot should be able to disengage the autopilot and take control of the airplane. This should be simple. My suspicion is that there is an inherent, more fundamental problem with the MAX. Before Boeing rushes a software fix, idependendent entities “(remember we can no longer assume the FAA is independent based on what transpired over the last few days) need to investigate and makes sure the plane is safe. I for one will not fly the MAX regardless of what the FAA and Boeing say. Their reputation for prudence and safety is gone.
- rosege 8y agoI agree! After Lion Air I would have been quite hesitant to fly on a Max. Now with all I'm reading - no way would I.
- sokoloff 8y agoThe Max has more powerful engines, mounted further forward on the wings (out of geometric necessity), and as a result has an aerodynamic center of lift further forward. From the addition of MCAS, I gather (but don’t know with certainty) that they couldn’t make some certification requirement without MCAS.
- VBprogrammer 8y ago> Why is MCAS needed? If the MAX is so similar to old 737’s and no additional training is needed, then why the MCAS? The most relevant question is “is the MAX aerodynamically stable?” If it is, why do we need the MCAS? That needs to be investigated. This isn't even a question. The 737 Max is completely aerodynamically stable. It does however exhibit control behaviours which are undesirable. A fair analogy for this is probably a car which oversteers, in general a normal family car is designed to understeer, because for your average driver that is safer. In the 737 Max the controls get lighter close to the stall because of lift generated by the engine nacelle. The certification requirements require that the controls don't get lighter. Boeing applied what now appears to be a poorly thought out fix. What might surprise you is that there are plenty of certified aircraft which are actually aerodynamically unstable, at least along the longitudinal axis. For example the 757 has dual yaw dampers and at least one of them needs to be serviceable before flight. The consensus is that at cruise altitude it would depart controlled flight without one of them working.
- peteretep 8y agoIf there’s any truth at all to the idea that Boeing applied inappropriate pressure, at any point, via any means, I’d like to see the rest of the world push back very heavily on Boeing imports
- growlist 8y agoIndeed, this is the type of thing US regulators love to hammer non-US companies with.
- jostmey 8y ago“A grand jury in Washington, D.C., issued a broad subpoena dated March 11 to at least one person involved in the 737 MAX’s development...” Given how cozy Boeing is with the US government, I fear that it will be the engineers and lower managers who are nailed to the wall, not Boeing’s leadership
- tyingq 8y agoOne area where the heavy unionization of this industry helps a bit. If it looks like the wrong people are being held accountable, there are several unions that can use their voice. Pilots, flight attendants, aerospace engineers, mechanics, etc.
- onetimemanytime 8y ago>>>Given how cozy Boeing is with the US government, I fear that it will be the engineers and lower managers who are nailed to the wall, not Boeing’s leadership Tricky, unless the management specifically told them to ignore safety. Otherwise, "I'm the CEO and that's why I have xx thousand engineers"
- bilbo0s 8y agoIt's not like software development. In fields like aviation and medical software, when engineers say something is done, there are usually documents to be signed. Right now, I don't think I'd like to be the guys who signed off on anything at all to do with MCAS or AoA indicators. I suspect very strongly that we won't find the CEO's signature on those documents. I always implore engineers in FDA regulated medical software and any engineers in aviation to please, please, PLEASE think more like engineers who build bridges and skyscrapers. When you're signing those documents, please understand that it's legally binding. Never let a higher up pressure you into signing such a document if you have any reservations at all.
- KineticLensman 8y ago> In fields like aviation and medical software, when engineers say something is done, there are usually documents to be signed Yes. In aviation, an engineer may have a formal role as a design authority or as a signatory on a safety case. They will typically have to themselves sign a letter, from an engineering director, that signals acceptance of this delegated responsibility. Most companies will have some way of matching the magnitude of the responsibility to the experience level of the engineer. And enlightened companies will have a no-fault 'stop-work' mechanism that pushes sign-off responsibility upward if engineers cannot in all conscience sign off something that they consider to be poorly designed or high risk.
- DennisP 8y ago> Boeing was toying with a new plane to replace the 737, launched in 1967, and had engineers working on the new plane concept. While many airlines liked the idea, existing 737 customers didn’t want to retrain their pilots at huge cost and so lobbied for an updated, more-efficient 737 > Then in 2011 Boeing learned that American Airlines, one of its best customers, had struck a tentative deal with Airbus for potentially hundreds of A320neo planes to renew its short-haul fleet. American has 304 737s not including the Max.[0] So Boeing considered building a whole new plane, reconsidered when 737 customers wanted to avoid retraining, then did the Max when one of them started moving to a whole new plane anyway. Something somewhere seems not quite thought through. [0] https://en.wikipedia.org/wiki/American_Airlines_fleet#Current_fleet https://en.wikipedia.org/wiki/American_Airlines_fleet#Curren...
- tyingq 8y agoSouthwest has 750+ 737's. Giving them a reason to look at Airbus could have been risky.
- erentz 8y ago> Something somewhere seems not quite thought through. Maybe timing was also an issue, the A320 reengine was (supposed to be) a fairly quick program. A whole new airplane for Boeing presumably would’ve taken a lot longer. For a lot of customers looking to replace 737s in the near future maybe too long to wait. So * A320neo sooner beats $NewBoeing later * 737MAX same time beats A320neo for existing 737 operators * 737MAX and A320neo a toss up for other scenarios Edit: and if you’re a 737 operator waiting for a new plane is a very risky proposition with delays, etc. It would be less risky if you’re going to have to retrain your pilots to buy the 320.
- exabrial 8y agoI think the FAA already has a healthy culture of failure analysis that makes is _actually safe_, not just a feel good safe. I don't want to see a bunch of malicious prosecutors and lawyers get involved.
- bilbo0s 8y agoIn fairness to the Administration here, that "healthy culture of failure analysis" always included the threat of "malicious prosecutors and lawyers". Places like the FAA and the FDA just never put the threat of prison out front and center. Unless they have to. I'm not certain this is one of those times, we need more information. But throwing people in prison is very much the appropriate thing to do in certain circumstances.
- rangersanger 8y agoI’m trying to recall some of the more recent air accidents and the resultant investigations. I don’t remember getting blow by blow updates to the ongoing investigation. Is this new?
- MS90 8y agoThe scenarios are a bit different, but MH370 dominated the news cycle for what seemed like an eternity...
- JustSomeNobody 8y ago> A Boeing spokesman didn’t respond to a request for comment about the inspector general’s probe. Earlier, a Boeing spokesman said: “The 737 MAX was certified in accordance with the identical FAA requirements and processes that have governed certification of all previous new airplanes and derivatives. The FAA considered the final configuration and operating parameters of MCAS during MAX certification, and concluded that it met all certification and regulatory requirements.” But Bloomberg has an article[0] where the FAA basically handed over much of the process to Boeing. So, of course it was certified in accordance with FAA requirements! [0] https://www.bloomberg.com/news/articles/2019-03-18/boeing-drops-as-role-in-vetting-its-own-jets-comes-under-fire-jtecyagp?srnd=premium https://www.bloomberg.com/news/articles/2019-03-18/boeing-dr...
- gdubs 8y agoIt already looked bad for the FAA that they dragged their feet to ground the plane. That a criminal investigation was launched a full day before they finally grounded the Max raises even more questions. You have the whole world grounding the plane, two highly unusual, strikingly similar tragedies within a short span of time, and a federal investigation into the plane's development, and it still takes a whole day to ground the plane?
- cmurf 8y agoI agree with the questions. It's a what's going on here? And that may be the main goal of the prosecutor for all we know at this point. Grand juries are a bit archaic, it does allow the prosecutor to basically suggest "hey I'm not the only one who thinks this is fishy, I've convinced a grand jury it's fishy" - however there are no defense lawyers allowed to make contra arguments before grand juries so it's not an adversarial system. Yet.
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- dirkg 8y agoIIRC FAA didnt ground the plane. Trump issued an order and FAA were forced to do it.
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- dirkg 8y agoThe simple fact is that if either of these were true - - a US airline was involved in the accident, esp on US soil - a non-US company was the manufacturer then the FAA would've grounded the plane almost immediately instead of publicly declaring it was safe, which was obvious nonsense. In addition, US media made fun of other countries for grounding the plane. The whole thing just shows how biased FAA/US govt has been.