11 ms·

I wonder who is going to have the guts to kill the 737 Max for good. It's never going to fly with airline and passengers ever again,

hn_throwaway_99 6y ago
That seems like a huge mistake to me. As it's been said many times, "Safety regulations are written in blood." At this point we probably know more about the flaws in the MAX than almost any other aircraft. And it's not like the plane was fundamentally unsound at a design level, but that bean counting, shortcuts and a failing culture made it unsound. I mean, I haven't heard anyone of authority say the flaws with the Max aren't fixable. If the Max "never flies again", it will just be because it's rebranded, not because it's a fundamentally different aircraft.
- paganel 6y ago
  > And it's not like the plane was fundamentally unsound at a design level, but that bean counting I'm not an airframe designer by any means but from the countless threads that I've read on this website about this subject (coming from people who seemed more knowledgable than me on the subject) it did seem like the plane was fundamentally unsound at a design level.
  - jmarbach 6y ago
    Same. My understanding is that adding larger engines, and moving them forward on the wing, make the the airframe unable to fly at level altitude without software automatically adjusting the pitch.
    - throwanem 6y ago
      Not quite. The issue is that, due to the engine placement and its effect on center of gravity, the aircraft will tend past a certain angle of attack to start nosing into a stall, rather than away from one. MCAS was added to counteract this highly counterintuitive and dangerous tendency by automatically driving the horizontal stabilizer to nose the aircraft back toward level flight. As I understand it, the 737 MAX was the first commercial airframe ever approved by the FAA with this sudden inflection point in behavior when approaching a stall. (There's a term for it, something like "positive rate characteristic", but I forget. Perhaps someone who knows it will mention it here.) Seeing how well that worked out, one hopes it'll also be the last such airframe approved.
      - stephen_g 6y ago
        They're pretty adamant that it's not an anti-stall feature - those normally have 'stick pushers' or shakers.
        throwanem 6y ago
        Considering that both crashes occurred because of MCAS acting as intended on the basis of invalid data from a failed AoA sensor with no backup, I feel like that would be a surprising lie for Boeing to have told. edit: And, having checked the Wikipedia page for the system, I find myself surprised that that is in fact a lie Boeing has told. They may as well go ahead and try to rebrand the damned thing, I guess. On top of everything else they've done, I can't see how it would make their problems any worse... also edit: Via Wikipedia, 14 CFR 25.203: "No abnormal nose-up pitching may occur. The longitudinal [pitch] control force must be positive up to and throughout the stall." This is the characteristic the MAX lacks due to the engine placement. If you want to add an active system to correct for that, the AoA sensor is what you use to drive it, since that's what tells you the difference between the direction of airflow and the angle of the wing. That's how you know you're approaching a stall, and need to add a negative pitching moment. But if that sensor jams, which being a mechanical device it can do, and you don't have input from another sensor so you can see the disagreement, you risk spurious activation of the system when it isn't needed, potentially forcing the aircraft out of level flight. I get that it's in Boeing's interest to claim MCAS isn't an anti-stall system. Why would they say anything else? To do so would implicitly admit not only that they built an aircraft that would fail dangerously in a common situation, but also that the FAA let them get away with selling it and selling it as type-identical with prior versions lacking the fail-dangerous characteristic. Neither admission would serve their interests. But, equally, why should we take them at their word on this, or indeed anything? It's pretty clear that their corporate interests have ceased to align with ours as potential airline passengers. It's generous unto foolishness, in light of that, to give them the benefit of any doubt whatsoever. https://www.law.cornell.edu/cfr/text/14/25.203 https://www.law.cornell.edu/cfr/text/14/25.203
        ashtonkem 6y ago
        They were pretty desperate to maintain the 737 type certification, to reduce airline adoption cost. So the question is: are they right, or are they stretching the truth via motivated reasoning?
    - valesco 6y ago
      My own understanding is that the whole problem is to avoid the costly pilot training on the MAX by making it behave like a regular 737. That's where the automatic pitch adjustment at high angles of attack comes from. Had Boeing decided that companies would have to train the pilots for a new type of aircraft (which the MAX actually is), none of this would have happened.
      - ashtonkem 6y ago
        This is actually the problem. If they were willing to change the type certification, they would have been free to raise the airplane up and keep the engines in their proper position. The need to keep type certifications the same is the root cause of a whole series of bad decisions, including engine placement and the unwillingness to change pilot training & documentation.
        rootusrootus 6y ago
        > free to raise the airplane up How do you suppose they might do that without completely redesigning the plane? I don't think type recertification is why they kept the landing gear the same length.
        ashtonkem 6y ago
        There certainly would be other costs associated with that, but the primary motivator for not redesigning their aircraft was maintaining type certification, not the cost of a clean redesign. If the Max8 could keep the same type certification, pilots could cross over without long and expensive training, and without losing their rating on their prior aircraft, making adoption a no brainer. If the Max8 doesn’t keep a type rating, there’s less of an incentive for current 737 customers to buy a Max8, since they’ll have to go through the same logistical hurdles that introducing a A321neo would have. Plus Southwest basically won’t buy anything but 737s, so maintaining that type rating was critical to selling the new plane to one of their biggest customers.
        selectodude 6y ago
        It absolutely is. Boeing already made a stretched 737 with larger engines. It's called the 757 and they stopped making it because airlines wanted bigger 737s.
    - stephen_g 6y ago
      I don't believe that is the case. The MCAS system was added because the handling of the plane was different to previous models at higher angles of attack. The system was meant to compensate to give the same handling 'feel' as older 737s to pass certification without requiring significant re-training of pilots.
    - FabHK 6y ago
      I believe that is overstating things. From what I gather, it is during specific flight conditions, namely high angles of attack at high airspeeds, encountered during an extreme manoeuvre (definitely not straight and level flight), namely a wind-up turn (a turn at increasing bank angle and constant speed and constant power (note that this implies accelerating descent), rarely if ever encountered during a routine flight). This is flown to test the stick force as a function of load factor. Now, it is a certification requirement that the stick force increases basically linearly with the load factor ("The stick force curve must have a stable slope" [3]), and that was not given - the stick slacked. This is what MCAS was designed to address. From what I gather, a 737 MAX without MCAS would not be certifiable, but safely flyable, possibly with some surprising, but manageable behaviour under very rare circumstances: namely, flying at a high angle of attack with high speed would require you to release some stick force instead of having to pull hard to keep the nose up. Having said that, the whole saga has revealed so many problems at Boeing and the FAA that I am reluctant to fly the 737 MAX and 787 myself. https://www.seattletimes.com/seattle-news/times-watchdog/the-inside-story-of-mcas-how-boeings-737-max-system-gained-power-and-lost-safeguards/ https://www.seattletimes.com/seattle-news/times-watchdog/the... https://www.scribd.com/document/53095046/NASA-Information-Summaries-Wind-Up-Turn https://www.scribd.com/document/53095046/NASA-Information-Su... [3] https://www.law.cornell.edu/cfr/text/14/25.175 https://www.law.cornell.edu/cfr/text/14/25.175
    - ehnto 6y ago
      That's not really an accurate depiction. All planes constantly change the control settings required during different flight conditions in order to maintain level flight, often with software. Different speeds, flaps, weather conditions all require different trims to those control settings. If your plane gets new flight characteristics through a design change, the configurations your training told you should work will probably not work anymore. What Boeing did was hide the change in flight characteristics caused by the new engines using software, so pilots didn't need to retrain, and they borked the implementation.
  - rootusrootus 6y ago
    > threads that I've read on this website I strongly recommend not getting your 737-MAX facts from HN. Every time the topic comes up, the discussion continues to be riddled with inaccuracies, many of them strongly held beliefs.
  - jaywalk 6y ago
    It's absolutely not unsound at any level. It simply handles differently than pre-MAX 737s in certain scenarios, which would have required pilot re-certification if not for the flawed MCAS software.
    - catalogia 6y ago
      From what I understand it would not get certified today if it were introduced as a new airplane completely unrelated to any others, for a variety of obscure reasons. However if the original 737 in the 60s had the design of the MAX, its pilots would be taught how to fly it without any MCAS software and it would fly just fine.
      - jaywalk 6y ago
        You understand incorrectly. The 737 MAX would have no trouble being certified as a new type without MCAS. Boeing did not forget how to design planes.
        genoapol 6y ago
        Without MCAS wouldn't the plane be unbalanced due to engine placement issues and excess weight? From my understanding, the MCAS system was built to offset these problematic default states that come with using an old body not compatible with the upgrades made. I also heard the weight of these new engines caused wings to develop stress cracks. Not sure how it could be considered safe without a better designed MCAS system and addressing the other issues.
        dan_quixote 6y ago
        You seem to be conflating ideas. jaywalk said it best with: > It simply handles differently than pre-MAX 737s in certain scenarios It handles differently than previous 737s due to airframe changes (namely engine position). MCAS was meant to "correct" this for the purpose of skipping re-certification. The airframe isn't fundamentally flawed, the process of certifying it this round was flawed. Which caused Boeing engineers to implement a flawed MCAS system.
  - scoopertrooper 6y ago
    There is nothing wrong with using software to correct for instability; the B-2 Spirit is far less aerodynamically stable then the Max and it's only had one crash in its entire 23 year service history. Boeing failed to provide sufficient redundancy for the MCAS system and proper training to the air crews.
    - AnimalMuppet 6y ago
      It wouldn't surprise me, though, if in its entire service history, the B-2 has had fewer total flights than the 737 Max has...
      - jellicle 6y ago
        One way to look at it is that 5% of all B-2s ever built have crashed.
      - linuxftw 6y ago
        Not to mention to most rigorously trained pilots and the face of the planet. Not to mention the tops minds designing the Aircraft and the software, rather than outsourcing it to code-by-the pound shops like Boeing did.
    - freehunter 6y ago
      Military planes fly a little differently from passenger planes and the humans inside those planes expect different handling characteristics.
- sjm-lbm 6y ago
  > probably know more about the flaws in the MAX The thing is, we do know a lot about those flaws and the only way to really fix those flaws is with a clean-sheet redesign. The MAX would have flown again, for sure, pre-COVID. However, designs without known fundamental design flaws can handle worldwide airline lift needs for the foreseeable future.. and it's legitimate to wonder what that means for the future of the MAX.
  - hn_throwaway_99 6y ago
    > The thing is, we do know a lot about those flaws and the only way to really fix those flaws is with a clean-sheet redesign. That's just not true. People seem to be conflating the fact that the design required software-controlled stability (e.g. MCAS) as a "fundamental" design issue. That's just not the case. The problems were: 1. MCAS was not sufficiently redundant. 2. Boeing tried to get away with the changes to the MAX without requiring recertification or pilot retraining, which was just wrong. Both #1 and #2 have straightforward fixes.
    - GekkePrutser 6y ago
      Yes, I'm kinda surprised they didn't use the COVID lockdown period to do proper pilot training. Most pilots and planes were basically sitting idle anyway. It's good for them to remain somewhat active. And fuel was given away for pretty much free because the overproduction was filling up expensive storage space. This would have been the ideal moment to teach 737 pilots to properly handle the Max aircraft without needing MCAS.
      - kayfox 6y ago
        > This would have been the ideal moment to teach 737 pilots to properly handle the Max aircraft without needing MCAS. Well, its not legal to have the 737 MAX without MCAS, so its a moot point. MCAS exists to compensate for undesired control forces as high (near-stall) angles of attack, its not legal to have those performance characteristics in an aircraft. If this was Airbus, this would have been done in software since the A320 series is fly by wire.
- numpad0 6y ago
  Freight carriers still fly MD-11 as they’re economical and its flaws are well understood, but passenger carriers don’t touch it or the TriStar with a 10ft pole, I think that’s the answer.
  - AnimalMuppet 6y ago
    Not sure the 737 Max is big enough to be a freighter, though.
    - kayfox 6y ago
      Alaska Airlines operates a number of 737 freighters because of how Alaska the state works logistics wise. People in Alaska will do things like come down to Anchorage and buy all their supplies for several months from Fred Meyers and Costco and box it all up on a freight pallet and have Alaska Air ship it back to the remote area these people live in.
- kube-system 6y ago
  I think this might have some truth to it. For example, the DC-10 was also a flawed airplane with a terrible safety record in the 70's which was grounded by the FAA as a result. But the flaws were fixed and the plane is still in operation today, now with a safety record comparable to other similar planes.
  - Theodores 6y ago
    Cargo bay doors was the problem with the DC-10. The doors were re-engineered so they were fail safe. They did have other problems but fixing the door latches was it. This is in a different league of design fault to the 737 Max and MCAS. Furthermore this was in a different era before the internet. People only had the mainstream news to go on. https://www.bbc.co.uk/news/uk-england-birmingham-26259236#:~:text=A%20new%2C%20outward-opening%20cargo,the%20cabin%20prone%20to%20depressurising.&text=On%2025%20May%201979%2C%20271,was%20identified%20as%20the%20cause https://www.bbc.co.uk/news/uk-england-birmingham-26259236#:~....
    - kube-system 6y ago
      How is it in a different league? We know why the planes crashed, and we know what to do to fix it. Add some AOA redundancies, and get a new type certification that requires pilot retraining. Safety is not a complicated goal to achieve. You identify hazards and you rectify them. The hard part is identifying them, which in this case has already tragically happened.
      - Theodores 6y ago
        Not really. The fix for the cargo doors was not affecting the aerodynamics, centre of gravity and how the plane handled. The pilots didn't need updated type certification for the fixed cargo doors. Your easy fixes for the dreaded 737 max sound like those of an armchair expert.
        kube-system 6y ago
        It is my understanding that the inherent handling characteristics of the 737 Max would have been acceptable under a new type certification, without MCAS. Is this incorrect?
linuxftw 6y ago
My guess is Russia or China. Then the US will be fomented into supporting this terrible plane as a patriotic duty. People will start taking "Freedom Flights" to prove to those bad people "over there" that America is #1!
LatteLazy 6y ago
Or just rebrand it. I'm sort of amazed they haven't done that already...
- BitwiseFool 6y ago
  I don't know about you, but I never want to fly on a 737 MAX no matter what they rename it. Every time I have booked a ticket online the website tells me what kind of aircraft I would be flying on.
  - flyinglizard 6y ago
    That’s exactly what the rebranding is for.
  - dom96 6y ago
    As nice as this info is, is there any actual guarantee that it is valid? I wouldn't be surprised if airlines switch planes around all the time, so by the time you check in you may be flying a MAX plane (and possibly not even be aware).
    - mstade 6y ago
      This is anecdotal, but I've never once out of hundreds of flights experienced what you're describing. Sure, replacement flights when things got cancelled may have been on a different aircraft, but then it's a different flight altogether so not particularly surprising. I'd be curious to know if under normal circumstances they ever fly a plane other than the one listed, I have no idea. Edit: to clarify a bit, I know this because I'm a nerd and sometimes pick flights specifically because of the type of plane used. I quite enjoyed the A380. :o)
      - txcwpalpha 6y ago
        It doesn't happen on something like an A380 (especially since there isn't exactly any other plane type to switch to from an A380 without huge issues), but it's pretty common on smaller jets, especially in the A320 family or 737 family where they are nearly-identically-sized jets that can be swapped out easily. If you're scheduled to fly on a 737-800 but there's a problem with the jet, they might swap it out for a 737-400 (which is pretty much just an older generation of the -800, similar to how the -800 is an older generation of the MAX 8) and it would go completely unnoticed by almost every passenger. That happens less often nowadays that most (all?) of the -400s are retired, but I would expect it to start happening again once the MAXs return to service and they are being deployed side-by-side with the NGs.
bjarneh 6y ago
> It's never going to fly with airline and passengers ever again, What are Boing's alternatives here? I guess they should go back to the drawing board and scrap this idea of just adding some large engines on a plane that was not made for them. But that fatal idea, have put them in a horrible position. The airline business seems to be very much about saving money on fuel, and creating a new fuel efficient airplane is going to take a lot of time (which is guess is why they did this quick and dirty hack the last time, to stay competitive). In a business like that trust is everything, and I feel the more they are trying to force people into that flawed airplane, the less likely it seems that people will trust them ever again.
- rbanffy 6y ago
  The reason Boeing went with adding bigger engines to small a plane that couldn't have them is because airlines also like to save money in training and certification. If Boeing made them spend money in new training, they could spend money in better planes from the competition as well.
- Gravityloss 6y ago
  Well, now is the time for a clean sheet design. There isn't going to be any near term demand anyway. When production really kicks in ten years from now, the world will look different - everybody is flying really old gas guzzler planes.
- pcurve 6y ago
  Yep. Trust is everything. Boeing is already on thin ice. Just imagine, there is one more crash related to this, and what the fall out would be. Boeing as a company would be toast. That's the risk Boeing is dealing with on hand. And it won't be just Boeing's problem, it will also be airlines' problems for not taking firmer stance.
  - syshum 6y ago
    Boeing's passenger plane business would be done But the Space and Defense Contracts would be more than enough to keep the company around
david38 6y ago
Of course it will. Software is much cheaper to iterate on than say wing design.
- walkingolof 6y ago
  I would assume that most work is done in something like Dassault Systèmes Catia etc, so the wing is software also for most of its life...
  - dan_quixote 6y ago
    As soon as the tooling begins manufacture, it's a heck of a lot more difficult to make revisions. It takes about 2 years from the beginning of tooling manufacture until the first wing parts touch it (validation testing). And another year or three before actual, meant-to-fly, wing parts touch it. Any changes to wing design risk rebooting the entire process I just described. Additionally, the people doing this work are an extremely limited resource. Major schedule changes disrupt all the future work they previously scheduled. You can't just bring in some contractors to fill in because the work is rather new/novel every time.
alkonaut 6y ago
Pre-covid I would have said of course it will fly. Because there is too much money at stake. Airlines aren't going to just cancel their orders and sell their MAX-8's and buy Airbus (suing Boeing for the difference). Now with Covid, another possibility has opened up: a massive surplus of aircraft for the coming decade might actually make it redundant. Airlines will die left and right and there will be more than enough cheap planes to go around even without the MAX-8's. I'd have no problem flying in one, as soon as authorities approve it.
- catalogia 6y ago
  The MAX-8 was meant to be more fuel efficient than previous 737s, and from what I understand fuel is a huge expense for airlines. Could airliners truly become so cheap that fuel costs are no longer a consideration?
  - scoopertrooper 6y ago
    Assuming the airliner surplus portends a medium term economic slowdown, then fuel will also likely be quite cheap.
  - alkonaut 6y ago
    The scenario I was considering was one where the half of the global fleet that is old/inefficient aircraft is kept grounded, but the modern part of the global fleet (e.g. A321 as an alternative to MAX8) is flying, and is big enough to cover the need.
  - russb 6y ago
    Much easier to just increase ticket prices than offset fuel costs by buying more efficient jets. In a healthy environment, there’s always downward pressure on ticket costs, and you have to find efficiencies elsewhere. We aren’t in a healthy environment anymore...
  - manquer 6y ago
    Fuel costs are bigger consideration in long haul flights (planes fly 12 hours a day ) than short ones (planes fly only 4-5 hrs a day). Long flights traditionally were serviced by wide body aircraft , in recent years with longer range and favourable ETOPS regulations narrow aircraft like 737 max and 320neo were desirable for low volume long haul routes. Also at the time of design in 2010 jet fuel prices were at all time highs , fuel prices are at all time low now . Given the surplus in the market , Low fuel prices, drop in demand the ROI for investing in 737 max may not simply exist anymore.
kn0where 6y ago
The international regulators are getting their modifications made. The plane is undergoing new flight tests as of this week. It will be a slow restart due to COVID but the plane has survived the biggest obstacles already. It will be in passenger service again.
V_Terranova_Jr 6y ago
This reflects a lack of understanding how the U.S. Government works. There's essentially zero chance your statement is correct. There will be changes made to the aircraft, changes to training regimen, multiple reviews, etc., but the 737 Max will be recertified to fly. That shouldn't be taken as an endorsement, just an acknowledgement of reality. Source: You can look up my profile and comment history. I don't work on the civil side, but I know how things work in the USG.

hn_throwaway_99 6y ago

That seems like a huge mistake to me. As it's been said many times, "Safety regulations are written in blood." At this point we probably know more about the flaws in the MAX than almost any other aircraft. And it's not like the plane was fundamentally unsound at a design level, but that bean counting, shortcuts and a failing culture made it unsound. I mean, I haven't heard anyone of authority say the flaws with the Max aren't fixable. If the Max "never flies again", it will just be because it's rebranded, not because it's a fundamentally different aircraft.

paganel 6y ago
> And it's not like the plane was fundamentally unsound at a design level, but that bean counting I'm not an airframe designer by any means but from the countless threads that I've read on this website about this subject (coming from people who seemed more knowledgable than me on the subject) it did seem like the plane was fundamentally unsound at a design level.
- jmarbach 6y ago
  Same. My understanding is that adding larger engines, and moving them forward on the wing, make the the airframe unable to fly at level altitude without software automatically adjusting the pitch.
  - throwanem 6y ago
    Not quite. The issue is that, due to the engine placement and its effect on center of gravity, the aircraft will tend past a certain angle of attack to start nosing into a stall, rather than away from one. MCAS was added to counteract this highly counterintuitive and dangerous tendency by automatically driving the horizontal stabilizer to nose the aircraft back toward level flight. As I understand it, the 737 MAX was the first commercial airframe ever approved by the FAA with this sudden inflection point in behavior when approaching a stall. (There's a term for it, something like "positive rate characteristic", but I forget. Perhaps someone who knows it will mention it here.) Seeing how well that worked out, one hopes it'll also be the last such airframe approved.
    - stephen_g 6y ago
      They're pretty adamant that it's not an anti-stall feature - those normally have 'stick pushers' or shakers.
      - throwanem 6y ago
        Considering that both crashes occurred because of MCAS acting as intended on the basis of invalid data from a failed AoA sensor with no backup, I feel like that would be a surprising lie for Boeing to have told. edit: And, having checked the Wikipedia page for the system, I find myself surprised that that is in fact a lie Boeing has told. They may as well go ahead and try to rebrand the damned thing, I guess. On top of everything else they've done, I can't see how it would make their problems any worse... also edit: Via Wikipedia, 14 CFR 25.203: "No abnormal nose-up pitching may occur. The longitudinal [pitch] control force must be positive up to and throughout the stall." This is the characteristic the MAX lacks due to the engine placement. If you want to add an active system to correct for that, the AoA sensor is what you use to drive it, since that's what tells you the difference between the direction of airflow and the angle of the wing. That's how you know you're approaching a stall, and need to add a negative pitching moment. But if that sensor jams, which being a mechanical device it can do, and you don't have input from another sensor so you can see the disagreement, you risk spurious activation of the system when it isn't needed, potentially forcing the aircraft out of level flight. I get that it's in Boeing's interest to claim MCAS isn't an anti-stall system. Why would they say anything else? To do so would implicitly admit not only that they built an aircraft that would fail dangerously in a common situation, but also that the FAA let them get away with selling it and selling it as type-identical with prior versions lacking the fail-dangerous characteristic. Neither admission would serve their interests. But, equally, why should we take them at their word on this, or indeed anything? It's pretty clear that their corporate interests have ceased to align with ours as potential airline passengers. It's generous unto foolishness, in light of that, to give them the benefit of any doubt whatsoever. https://www.law.cornell.edu/cfr/text/14/25.203 https://www.law.cornell.edu/cfr/text/14/25.203
      - ashtonkem 6y ago
        They were pretty desperate to maintain the 737 type certification, to reduce airline adoption cost. So the question is: are they right, or are they stretching the truth via motivated reasoning?
  - valesco 6y ago
    My own understanding is that the whole problem is to avoid the costly pilot training on the MAX by making it behave like a regular 737. That's where the automatic pitch adjustment at high angles of attack comes from. Had Boeing decided that companies would have to train the pilots for a new type of aircraft (which the MAX actually is), none of this would have happened.
    - ashtonkem 6y ago
      This is actually the problem. If they were willing to change the type certification, they would have been free to raise the airplane up and keep the engines in their proper position. The need to keep type certifications the same is the root cause of a whole series of bad decisions, including engine placement and the unwillingness to change pilot training & documentation.
      - rootusrootus 6y ago
        > free to raise the airplane up How do you suppose they might do that without completely redesigning the plane? I don't think type recertification is why they kept the landing gear the same length.
        ashtonkem 6y ago
        There certainly would be other costs associated with that, but the primary motivator for not redesigning their aircraft was maintaining type certification, not the cost of a clean redesign. If the Max8 could keep the same type certification, pilots could cross over without long and expensive training, and without losing their rating on their prior aircraft, making adoption a no brainer. If the Max8 doesn’t keep a type rating, there’s less of an incentive for current 737 customers to buy a Max8, since they’ll have to go through the same logistical hurdles that introducing a A321neo would have. Plus Southwest basically won’t buy anything but 737s, so maintaining that type rating was critical to selling the new plane to one of their biggest customers.
        selectodude 6y ago
        It absolutely is. Boeing already made a stretched 737 with larger engines. It's called the 757 and they stopped making it because airlines wanted bigger 737s.
  - stephen_g 6y ago
    I don't believe that is the case. The MCAS system was added because the handling of the plane was different to previous models at higher angles of attack. The system was meant to compensate to give the same handling 'feel' as older 737s to pass certification without requiring significant re-training of pilots.
  - FabHK 6y ago
    I believe that is overstating things. From what I gather, it is during specific flight conditions, namely high angles of attack at high airspeeds, encountered during an extreme manoeuvre (definitely not straight and level flight), namely a wind-up turn (a turn at increasing bank angle and constant speed and constant power (note that this implies accelerating descent), rarely if ever encountered during a routine flight). This is flown to test the stick force as a function of load factor. Now, it is a certification requirement that the stick force increases basically linearly with the load factor ("The stick force curve must have a stable slope" [3]), and that was not given - the stick slacked. This is what MCAS was designed to address. From what I gather, a 737 MAX without MCAS would not be certifiable, but safely flyable, possibly with some surprising, but manageable behaviour under very rare circumstances: namely, flying at a high angle of attack with high speed would require you to release some stick force instead of having to pull hard to keep the nose up. Having said that, the whole saga has revealed so many problems at Boeing and the FAA that I am reluctant to fly the 737 MAX and 787 myself. https://www.seattletimes.com/seattle-news/times-watchdog/the-inside-story-of-mcas-how-boeings-737-max-system-gained-power-and-lost-safeguards/ https://www.seattletimes.com/seattle-news/times-watchdog/the... https://www.scribd.com/document/53095046/NASA-Information-Summaries-Wind-Up-Turn https://www.scribd.com/document/53095046/NASA-Information-Su... [3] https://www.law.cornell.edu/cfr/text/14/25.175 https://www.law.cornell.edu/cfr/text/14/25.175
  - ehnto 6y ago
    That's not really an accurate depiction. All planes constantly change the control settings required during different flight conditions in order to maintain level flight, often with software. Different speeds, flaps, weather conditions all require different trims to those control settings. If your plane gets new flight characteristics through a design change, the configurations your training told you should work will probably not work anymore. What Boeing did was hide the change in flight characteristics caused by the new engines using software, so pilots didn't need to retrain, and they borked the implementation.
- rootusrootus 6y ago
  > threads that I've read on this website I strongly recommend not getting your 737-MAX facts from HN. Every time the topic comes up, the discussion continues to be riddled with inaccuracies, many of them strongly held beliefs.
- jaywalk 6y ago
  It's absolutely not unsound at any level. It simply handles differently than pre-MAX 737s in certain scenarios, which would have required pilot re-certification if not for the flawed MCAS software.
  - catalogia 6y ago
    From what I understand it would not get certified today if it were introduced as a new airplane completely unrelated to any others, for a variety of obscure reasons. However if the original 737 in the 60s had the design of the MAX, its pilots would be taught how to fly it without any MCAS software and it would fly just fine.
    - jaywalk 6y ago
      You understand incorrectly. The 737 MAX would have no trouble being certified as a new type without MCAS. Boeing did not forget how to design planes.
      - genoapol 6y ago
        Without MCAS wouldn't the plane be unbalanced due to engine placement issues and excess weight? From my understanding, the MCAS system was built to offset these problematic default states that come with using an old body not compatible with the upgrades made. I also heard the weight of these new engines caused wings to develop stress cracks. Not sure how it could be considered safe without a better designed MCAS system and addressing the other issues.
        dan_quixote 6y ago
        You seem to be conflating ideas. jaywalk said it best with: > It simply handles differently than pre-MAX 737s in certain scenarios It handles differently than previous 737s due to airframe changes (namely engine position). MCAS was meant to "correct" this for the purpose of skipping re-certification. The airframe isn't fundamentally flawed, the process of certifying it this round was flawed. Which caused Boeing engineers to implement a flawed MCAS system.
- scoopertrooper 6y ago
  There is nothing wrong with using software to correct for instability; the B-2 Spirit is far less aerodynamically stable then the Max and it's only had one crash in its entire 23 year service history. Boeing failed to provide sufficient redundancy for the MCAS system and proper training to the air crews.
  - AnimalMuppet 6y ago
    It wouldn't surprise me, though, if in its entire service history, the B-2 has had fewer total flights than the 737 Max has...
    - jellicle 6y ago
      One way to look at it is that 5% of all B-2s ever built have crashed.
    - linuxftw 6y ago
      Not to mention to most rigorously trained pilots and the face of the planet. Not to mention the tops minds designing the Aircraft and the software, rather than outsourcing it to code-by-the pound shops like Boeing did.
  - freehunter 6y ago
    Military planes fly a little differently from passenger planes and the humans inside those planes expect different handling characteristics.
sjm-lbm 6y ago
> probably know more about the flaws in the MAX The thing is, we do know a lot about those flaws and the only way to really fix those flaws is with a clean-sheet redesign. The MAX would have flown again, for sure, pre-COVID. However, designs without known fundamental design flaws can handle worldwide airline lift needs for the foreseeable future.. and it's legitimate to wonder what that means for the future of the MAX.
- hn_throwaway_99 6y ago
  > The thing is, we do know a lot about those flaws and the only way to really fix those flaws is with a clean-sheet redesign. That's just not true. People seem to be conflating the fact that the design required software-controlled stability (e.g. MCAS) as a "fundamental" design issue. That's just not the case. The problems were: 1. MCAS was not sufficiently redundant. 2. Boeing tried to get away with the changes to the MAX without requiring recertification or pilot retraining, which was just wrong. Both #1 and #2 have straightforward fixes.
  - GekkePrutser 6y ago
    Yes, I'm kinda surprised they didn't use the COVID lockdown period to do proper pilot training. Most pilots and planes were basically sitting idle anyway. It's good for them to remain somewhat active. And fuel was given away for pretty much free because the overproduction was filling up expensive storage space. This would have been the ideal moment to teach 737 pilots to properly handle the Max aircraft without needing MCAS.
    - kayfox 6y ago
      > This would have been the ideal moment to teach 737 pilots to properly handle the Max aircraft without needing MCAS. Well, its not legal to have the 737 MAX without MCAS, so its a moot point. MCAS exists to compensate for undesired control forces as high (near-stall) angles of attack, its not legal to have those performance characteristics in an aircraft. If this was Airbus, this would have been done in software since the A320 series is fly by wire.
numpad0 6y ago
Freight carriers still fly MD-11 as they’re economical and its flaws are well understood, but passenger carriers don’t touch it or the TriStar with a 10ft pole, I think that’s the answer.
- AnimalMuppet 6y ago
  Not sure the 737 Max is big enough to be a freighter, though.
  - kayfox 6y ago
    Alaska Airlines operates a number of 737 freighters because of how Alaska the state works logistics wise. People in Alaska will do things like come down to Anchorage and buy all their supplies for several months from Fred Meyers and Costco and box it all up on a freight pallet and have Alaska Air ship it back to the remote area these people live in.
kube-system 6y ago
I think this might have some truth to it. For example, the DC-10 was also a flawed airplane with a terrible safety record in the 70's which was grounded by the FAA as a result. But the flaws were fixed and the plane is still in operation today, now with a safety record comparable to other similar planes.
- Theodores 6y ago
  Cargo bay doors was the problem with the DC-10. The doors were re-engineered so they were fail safe. They did have other problems but fixing the door latches was it. This is in a different league of design fault to the 737 Max and MCAS. Furthermore this was in a different era before the internet. People only had the mainstream news to go on. https://www.bbc.co.uk/news/uk-england-birmingham-26259236#:~:text=A%20new%2C%20outward-opening%20cargo,the%20cabin%20prone%20to%20depressurising.&text=On%2025%20May%201979%2C%20271,was%20identified%20as%20the%20cause https://www.bbc.co.uk/news/uk-england-birmingham-26259236#:~....
  - kube-system 6y ago
    How is it in a different league? We know why the planes crashed, and we know what to do to fix it. Add some AOA redundancies, and get a new type certification that requires pilot retraining. Safety is not a complicated goal to achieve. You identify hazards and you rectify them. The hard part is identifying them, which in this case has already tragically happened.
    - Theodores 6y ago
      Not really. The fix for the cargo doors was not affecting the aerodynamics, centre of gravity and how the plane handled. The pilots didn't need updated type certification for the fixed cargo doors. Your easy fixes for the dreaded 737 max sound like those of an armchair expert.
      - kube-system 6y ago
        It is my understanding that the inherent handling characteristics of the 737 Max would have been acceptable under a new type certification, without MCAS. Is this incorrect?

linuxftw 6y ago

My guess is Russia or China. Then the US will be fomented into supporting this terrible plane as a patriotic duty. People will start taking "Freedom Flights" to prove to those bad people "over there" that America is #1!

LatteLazy 6y ago

Or just rebrand it. I'm sort of amazed they haven't done that already...

BitwiseFool 6y ago
I don't know about you, but I never want to fly on a 737 MAX no matter what they rename it. Every time I have booked a ticket online the website tells me what kind of aircraft I would be flying on.
- flyinglizard 6y ago
  That’s exactly what the rebranding is for.
- dom96 6y ago
  As nice as this info is, is there any actual guarantee that it is valid? I wouldn't be surprised if airlines switch planes around all the time, so by the time you check in you may be flying a MAX plane (and possibly not even be aware).
  - mstade 6y ago
    This is anecdotal, but I've never once out of hundreds of flights experienced what you're describing. Sure, replacement flights when things got cancelled may have been on a different aircraft, but then it's a different flight altogether so not particularly surprising. I'd be curious to know if under normal circumstances they ever fly a plane other than the one listed, I have no idea. Edit: to clarify a bit, I know this because I'm a nerd and sometimes pick flights specifically because of the type of plane used. I quite enjoyed the A380. :o)
    - txcwpalpha 6y ago
      It doesn't happen on something like an A380 (especially since there isn't exactly any other plane type to switch to from an A380 without huge issues), but it's pretty common on smaller jets, especially in the A320 family or 737 family where they are nearly-identically-sized jets that can be swapped out easily. If you're scheduled to fly on a 737-800 but there's a problem with the jet, they might swap it out for a 737-400 (which is pretty much just an older generation of the -800, similar to how the -800 is an older generation of the MAX 8) and it would go completely unnoticed by almost every passenger. That happens less often nowadays that most (all?) of the -400s are retired, but I would expect it to start happening again once the MAXs return to service and they are being deployed side-by-side with the NGs.

bjarneh 6y ago

> It's never going to fly with airline and passengers ever again, What are Boing's alternatives here? I guess they should go back to the drawing board and scrap this idea of just adding some large engines on a plane that was not made for them. But that fatal idea, have put them in a horrible position. The airline business seems to be very much about saving money on fuel, and creating a new fuel efficient airplane is going to take a lot of time (which is guess is why they did this quick and dirty hack the last time, to stay competitive). In a business like that trust is everything, and I feel the more they are trying to force people into that flawed airplane, the less likely it seems that people will trust them ever again.

rbanffy 6y ago
The reason Boeing went with adding bigger engines to small a plane that couldn't have them is because airlines also like to save money in training and certification. If Boeing made them spend money in new training, they could spend money in better planes from the competition as well.
Gravityloss 6y ago
Well, now is the time for a clean sheet design. There isn't going to be any near term demand anyway. When production really kicks in ten years from now, the world will look different - everybody is flying really old gas guzzler planes.
pcurve 6y ago
Yep. Trust is everything. Boeing is already on thin ice. Just imagine, there is one more crash related to this, and what the fall out would be. Boeing as a company would be toast. That's the risk Boeing is dealing with on hand. And it won't be just Boeing's problem, it will also be airlines' problems for not taking firmer stance.
- syshum 6y ago
  Boeing's passenger plane business would be done But the Space and Defense Contracts would be more than enough to keep the company around

david38 6y ago

Of course it will. Software is much cheaper to iterate on than say wing design.

walkingolof 6y ago
I would assume that most work is done in something like Dassault Systèmes Catia etc, so the wing is software also for most of its life...
- dan_quixote 6y ago
  As soon as the tooling begins manufacture, it's a heck of a lot more difficult to make revisions. It takes about 2 years from the beginning of tooling manufacture until the first wing parts touch it (validation testing). And another year or three before actual, meant-to-fly, wing parts touch it. Any changes to wing design risk rebooting the entire process I just described. Additionally, the people doing this work are an extremely limited resource. Major schedule changes disrupt all the future work they previously scheduled. You can't just bring in some contractors to fill in because the work is rather new/novel every time.

alkonaut 6y ago

Pre-covid I would have said of course it will fly. Because there is too much money at stake. Airlines aren't going to just cancel their orders and sell their MAX-8's and buy Airbus (suing Boeing for the difference). Now with Covid, another possibility has opened up: a massive surplus of aircraft for the coming decade might actually make it redundant. Airlines will die left and right and there will be more than enough cheap planes to go around even without the MAX-8's. I'd have no problem flying in one, as soon as authorities approve it.

catalogia 6y ago
The MAX-8 was meant to be more fuel efficient than previous 737s, and from what I understand fuel is a huge expense for airlines. Could airliners truly become so cheap that fuel costs are no longer a consideration?
- scoopertrooper 6y ago
  Assuming the airliner surplus portends a medium term economic slowdown, then fuel will also likely be quite cheap.
- alkonaut 6y ago
  The scenario I was considering was one where the half of the global fleet that is old/inefficient aircraft is kept grounded, but the modern part of the global fleet (e.g. A321 as an alternative to MAX8) is flying, and is big enough to cover the need.
- russb 6y ago
  Much easier to just increase ticket prices than offset fuel costs by buying more efficient jets. In a healthy environment, there’s always downward pressure on ticket costs, and you have to find efficiencies elsewhere. We aren’t in a healthy environment anymore...
- manquer 6y ago
  Fuel costs are bigger consideration in long haul flights (planes fly 12 hours a day ) than short ones (planes fly only 4-5 hrs a day). Long flights traditionally were serviced by wide body aircraft , in recent years with longer range and favourable ETOPS regulations narrow aircraft like 737 max and 320neo were desirable for low volume long haul routes. Also at the time of design in 2010 jet fuel prices were at all time highs , fuel prices are at all time low now . Given the surplus in the market , Low fuel prices, drop in demand the ROI for investing in 737 max may not simply exist anymore.

kn0where 6y ago

The international regulators are getting their modifications made. The plane is undergoing new flight tests as of this week. It will be a slow restart due to COVID but the plane has survived the biggest obstacles already. It will be in passenger service again.

V_Terranova_Jr 6y ago

This reflects a lack of understanding how the U.S. Government works. There's essentially zero chance your statement is correct. There will be changes made to the aircraft, changes to training regimen, multiple reviews, etc., but the 737 Max will be recertified to fly. That shouldn't be taken as an endorsement, just an acknowledgement of reality. Source: You can look up my profile and comment history. I don't work on the civil side, but I know how things work in the USG.