7 ms·

Boeing’s Homicides Will Give Way to Safety Reforms if Flyers Organize

72 points by mimixco 8y ago

whenchamenia 8y ago
This windbag proclaimed the swingarm to be unsafe at any speed, but having won plenty of local races with an old beetle, and autocrossed some corvairs, this guy is out to lunch. Sure, the sensor needs a redesign and some automation decisions were hot garbage, but 'never fly again' is just FUD.
- simion314 8y ago
  >Sure, the sensor needs a redesign and some automation decisions were hot garbage, but 'never fly again' is just FUD. Are you sure that only that except that MCAS all the other systems are fine and Boeing didn't cheap out on other systems, redesigned other things, other small updates etc? IMO the plane needs to be re-approved, this time for real.
  - _ph_ 8y ago
    Yes, for sure the whole approval process for the plane needs to be reviewed and repeated where necessary. But if it passed, it should fly again by all means.
    - Chris_Chambers 8y ago
      It already passed once. This is all the information you need to know the reviewers cannot be trusted. Why would you trust the results when it passes again?
jayonsoftware 8y ago
How long before we see "Is my flight a 737 Max " app
- vernie 8y ago
  Kayak added a filter for it last month.
quantumwoke 8y ago
Isn't the Boeing incident a symptom of poor engineering practices? Spaceships by all accounts seem to have similar if not higher levels of computer-controlled overrides to actually make the damn thing fly past Earth's atmosphere. The difference of course being that spaceship software is rigorously tested whereas Boeing was very lax in their implementation so they could rush the plane out the door. I don't see a problem with the idea of delegating aspects of flight to the computer - just fix the software engineering practices that lead to this tragedy. Please. :)
- xiphias2 8y ago
  No, there was no technical reason to design 737 MAX as it was designed, only regulatory reason. Regulations should help safety, not hinder it.
  - notfromhere 8y ago
    Boeing was trying to build a new plane to fit the technical specs of a previously approved plane to save some cash. Boeing's practice of cutting corners is why 300+ people are dead
    - xiphias2 8y ago
      I agree, I was trying to write the same thing. The body should be redesigned for the bigger engine.
      - notfromhere 8y ago
        The regulatory failure was that the FAA let them get away with it, rather than the regulations themselves.
        GiuseppaAcciaio 8y ago
        It's an interesting conundrum, because ultimately the FAA doesn't have more engineering expertise than Boeing so all they can do is force Boeing to prove that they have done their due diligence in confirming that the 737MAX can be operated under the same type rating as the 737NG. I'm guessing the next step for FAA and EASA will be to revise the process under which this approval was granted to Boeing.
usermac 8y ago
Read it and agree. I also want to ask if this model is on my flight. Do not want.
exabrial 8y ago
This looks like an attempt to get free press.
- vernie 8y ago
  This guy's just trying to move copies of "Unsafe at Any Speed", whatever that is.
  - nyamada 8y ago
    I'm hoping you're just being sarcastic. I have my problems with Ralph Nader (the 2000 presidential election) but I hope you know because of Nader that automobiles kill far, far fewer people than they did at the time of "Unsafe at Any Speed" (1965).
- rcchen 8y ago
  There's a bit of a nuance here - his grandniece was killed in the Ethiopian 737 accident [1] so it's personal at some level for him. [1]: https://www.npr.org/2019/04/04/709999296/ralph-nader-calls-for-recall-of-boeing-737-max-jets-after-his-grandniece-was-kil https://www.npr.org/2019/04/04/709999296/ralph-nader-calls-f...
  - exabrial 8y ago
    Mmm... didn't know that. I understand _why_ now, but, "never letting the 737 max fly again" is a purely emotional decision that helps no-one. They didn't tear down a 45 story building after the Hyatt Regency walkway collapse, as example. HN is showing a trend of purely blaming Boeing, but there were in fact several failures. Any one of: pilot training [There's a runaway stabilizer trim procedure that's actually a memory item for 737 pilots], not allowing single sensor inputs for flight control systems [FAA spec failure], the decision to allow the MCAS system to command an extreme amount of trim [engineering failure, should have been limited to a sane value] could have prevented the accidents.
patrickg_zill 8y ago
That seems to be premature since, while I respect Nader for many things, his own article points out that the investigations have not yet been completed.
PaulHoule 8y ago
The story that isn't being told is that smaller companies such as Bombardier and Embraer have made the investments in "clean sheet" small airliners that are much better than the 737 in every way. Boeing has used it's market power to keep these away from passenger and airlines. So it's not just a matter of people getting killed. It's people getting killed so you can pay more for airline tickets, have less room and comfort when you fly, have less frequent flights, hear more noise from airplanes, and experience more global warming. As for global warming note also that the 737 has terrible takeoff performance, even under favorable conditions it has twice the takeoff distance of some much larger airliners. Every hot summer you will hear that "airplanes are grounded because of the heat, but really "737s are grounded because of the heat" because the 737 can barely take off as it is. This is what secular stagnation looks like. It is undercompetition and underinvestment, just like we see with wireline internet service in the US. Don't let neoliberals fool you with the "there is no alternative" line because there is.
- tiredwired 8y ago
  Boeing bought Embraer.
  - GiuseppaAcciaio 8y ago
    No it didn't, you uninformed person. The two companies are in talks about a joint venture, but it's not yet ratified because the antitrust authorities in several countries haven't finished their due diligence yet.
- droussel 8y ago
  Boeing has sued Bombardier to keep it from selling their C-Series aircraft in the US which ultimately led to Bombardier basically giving away the aircraft to Airbus to stop bleeding out money.
- sandworm101 8y ago
  Bad takeoff performance does not mean a bad airframe. Takeoff performance and things like global warming (fuel efficiency) are often inversely related. No aircraft is perfect at all things. The big wings needed for shorter takeoff during a Nevada summer can mean more drag at altitude. Boeing builds for average customer conditions, not just the special case that is Vegas. (Altitude+heat+dry air = low air density = need bigger wings, bigger engines, and/or longer takeoff roll.)* *There is probably some room here for a joke about how people leave Vegas heavier than they were when they landed.
aglionby 8y ago
The author tells a familiar story of how we got here, but I think misses nuance on what the problem is. It's not the fact that software is used: it works fine normally, but the failure modes were insufficiently considered. > An aircraft has to be stall proof not stall prone. The F-117 begs to disagree.
- JshWright 8y ago
  Most combat jets "disagree". Most combat jets also have ejection seats for all occupants...
  - aglionby 8y ago
    It's not completely fair of me to compare civil jets to combat ones, but in any case I'd argue that ejection seats are perhaps more useful for the other scenarios combat planes find themselves in.
    - JshWright 8y ago
      Most ejections take place due to loss of control, not combat.
jasode 8y ago
I've been curious about some questions that I haven't seen discussed anywhere. HN isn't probably the best place to ask them but since I'm not on any forums where aerospace engineers hang out, I'll just ask here anyway: - Are physics computer simulations (e.g. aerodynamic flow[0]) realistic enough that engineers could have predicted the tendency for the nose to push up into a stall with the forward-mounted bigger engines while still at the CAD drawing stage? (Place some engines on the drawing with X amount of specified thrust, move them forward on the wing, then run a simulation, etc.) Or is the interaction of behavior so complex or so subtle that they had to build the real thing before realizing "Oops, our internal test pilots just noticed the plane is unstable and it looks like we need a software augmentation system!" - Could an unchanged 737-MAX flight simulator from last year reproduce the conditions for the Lion Air and Ethopia crashes? In other words, could a pilot used his/her imagination and said, "What if we make this AOA indicator give a bad reading -- what happens with MCAS?". Similar to how a pilot can choose to simulate a flamed-out engine, could one have chosen a stress-test scenario with a broken AOA sensor? (The infamous deleted video from MentourPilot showed his simulated struggles with turning the stabilizer trim against 400mph aerodynamic loads but it's not clear if a broken AOA can be simulated.) Yes, the 737-MAX was ultimately a failure of management and financial pressure but I'm curious if Boeing even had the technical debugging tools to predict this. [0] examples: https://www.youtube.com/results?search_query=aerodynamics++simulation https://www.youtube.com/results?search_query=aerodynamics++s...
- foobarbecue 8y ago
  Absolutely and almost certainly.
- dsfyu404ed 8y ago
  >Are physics computer simulations (e.g. aerodynamic flow[0]) realistic enough that engineers could have predicted the tendency for the nose to push up into a stall with the forward-mounted bigger engines while still at the CAD drawing stage? (Place some engines on the drawing with X amount of specified thrust, move them forward on the wing, then run a simulation, etc.) Or is the interaction of behavior so complex or so subtle that they had to build the real thing before realizing "Oops, our internal test pilots just noticed the plane is unstable and it looks like we need a software augmentation system!" Yes. They knew full well that the MAX would do that in circumstances where a normal 737 would not. There is nothing wrong with the MAX's performance characteristics. The aircraft itself is perfectly safe to fly. What isn't safe is the half baked MCAS system they used to deal with that edge case so they could avoid having to retrain pilots.
flyinglizard 8y ago
“The overriding problem is the basic unstable design of the 737 Max. An aircraft has to be stall proof not stall prone.“ Say what?
- _cerv 8y ago
  So a blimp?
- JshWright 8y ago
  The MAX has flight envelopes that are inherently unstable. The plan can get into a state where the aerodynamics of the plane make a stall worse, not better. For instance, the fact that the center of thrust is further forward (compared to other 737s) means that the plane pitches up when you give it more throttle. The default response to a stall is to increase the power, which pitches the nose up, which raises the angle of attack, which makes the stall worse. This inherent instability is why the MCAS was added to the MAX.
  - flyinglizard 8y ago
    Not a pilot, but I thought stall recovery is done through nose down first. Turbine engines take some time to respond to throttle up command and thrust on a loaded commercial plane is limited anyhow. An airframe is supposed to have a nose down tendencies upon stalling, which would make it recoverable. The Max may be more prone to stalling, but no one in their right mind would design a commercial airliner which can’t be recovered from stall.
    - JshWright 8y ago
      > I thought stall recovery is done through nose down first Exactly, which is why the nose-up tendency of the MAX is an issue.
      - flyinglizard 8y ago
        Pitch up tendencies under power to my understanding don’t make it an unstable airframe. If you stall, cut power, let go of the controls and the plane responds with a recoverable dive, it’s aerodynamically stable. Some airplanes can’t be (reliably) recovered from stall, that’s another issue altogether.
_ph_ 8y ago
As much as I think that Boeing took the wrong decision when going for the MAX instead of replacing the 737 from ground up and that the way the MCAS was developed and put into operations was a big disaster, both from Boeing and the FAA, as much do I disagree with that article. First of all, while most public know evidence points at MCAS as the source for the crashes, the accident investigations have not concluded yet. The article doesn't even mention that. But, with all what we know so far, Boeing has good reasons to significantly overwork the MCAS software and is doing so. I am not an aviation expert, but from all I have heard about the 737 MAX (from actual pilots), it looks like the airplane itself is not the issue, it was the specific faults in the MCAS implementation and that the pilots were not properly trained on the aircraft. Beyond fixing the obvious issues with the MCAS implementation, the biggest item for bringing the 737 MAX back into business needs to be pilot training. Training both how to fly the machine with MCAS deactivated as well as dealing with the potential failure szenarios of the MCAS system. Of course, the whole certification process for the 737 MAX needs to be reviewed to guarantee that the machine has the level of airworthyness one would expect. This is probably the most time-consuming step on the way to restoring its flight-status, but the most necessary one. Assuming that the 737 MAX after a significant update to the MCAS system passes a proper certification, in contrast to the article I would strongly argue for it to return into service. As much as we know for now, the machine isn't inherently unsafe to fly. But a cancellation could have drastic effects on air travel safety. Boeing decided against a new design in 2011 because of time constraints, and it is now 8 years later. A proper replacement for the 737 MAX wouldn't be ready for many years, probably only at the end of the next decade. If you are worried about safety, you certainly don't want Boeing to rush the development of a new design. Also, there would be little alternatives for replacement. Airbus could increase its output, but that also bears risk of general safety. As does flying the machines, the 737 MAX was meant to replace for more years. So, unless other issues with the 737 MAX are found in review, it definitely should be put back into business.
- GiuseppaAcciaio 8y ago
  Taking your argument a bit farther: let's assume that indeed the only issue present is a faulty MCAS implementation and that gets fixed. If the aircraft comes with additional training and certification requirements for pilots before it can be safely operated, then arguably it cannot be lumped into the same type rating as the 737NG. This would destroy the main selling point for Boeing (training pilots for a different type rating is a massive expense and headache for airlines), and would also mean that across the world there would be no pilots allowed to fly the existing 737MAX. The point about not cancelling the 737MAX because of the risk that the new models developed would be rushed and unsafe due to Boeing rushing the development of a new design is... not very plausible I'm afraid.
mimixco 8y ago
The key takeaway here is that the public will decide if they want the 737 Max or not. Boeing may have to shift to promoting Embraer designs (which they now own) while it develops a new small aircraft the public can trust, if such thing is even necessary. Public confidence in the DC-10 was destroyed after it had a series of related and back-to-back accidents. The plane was relegated to cargo status and Douglas never recovered financially, eventually selling to Boeing.
- dingaling 8y ago
  > The plane was relegated to cargo status No, it went back into passenger service and received further orders. American Airlines removed the "DC-10" sticker from the nose and carried on. I flew on the last commercial passenger service of a DC-10 in 2014.
ansible 8y ago
That position in the linked article is a bit extreme. The situation can be easily and safely fixed in software, but it will cost a lot of money. The MCAS system needs to step back to being an advisory-only system, just warning the pilots if it thinks a stall is immanent (and validate sensor inputs too). Then we will need to have extensive pilot training to deal with the different flight characteristics in the 737 MAX. This means a new type rating, which costs time and money... which the MCAS system was created to avoid. But yeah, the system as-is shouldn't be allowed to continue.
- blang 8y ago
  > That position in the linked article is a bit extreme. This is written by Ralph Nader, taking the extreme position has been his MO since 1965. As far as I can tell he takes a very hard position, in order to try and move the needle of public sentiment.
  - sofaofthedamned 8y ago
    Is he wrong?
- michelpp 8y ago
  > The MCAS system needs to step back to being an advisory-only system, just warning the pilots if it thinks a stall is immanent (and validate sensor inputs too). Then we will need to have extensive pilot training to deal with the different flight characteristics in the 737 MAX. There is already a stall warning alarm on all modern planes and have been for decades. I've only flown Cessnas (which all have stall warning horns), but from what I've read the intention of the MCAS is to reproduce the "stick feel" of an older 737 at high angles of attack and high thrust. The MAX is not "fly-by-wire" it has mechanical cable linkages from the stick to the control surfaces, forces are transmitted in both directions which the pilot can literally feel as resistance to control inputs. Boeing inadvertently changed the feeling of the airplane's response to the pilot. An older 737 would present much more resistance to pulling the plane harder into a stall, the MAX has less resistance. MCAS was intended to provide artificial resistance.
dsfyu404ed 8y ago
Turn off MCAS. Train the pilots on the MAX like it's a new type. Problem solved. This whole problem exists because Boeing tried to use software to fudge how the plain handles in order to avoid expensive retraining. Bite the bullet, train the pilots and the problem doesn't exist anymore. This entire article comes across as though an old man has read something he doesn't like in the newspaper and is suddenly an expert on it in order to justify his outrage when in reality the situation is much more nuanced than his understanding.
- bilbo0s 8y ago
  You have to wonder why this wasn't done in the first place? Are people really that greedy? You don't want to think they are, but at the same time you struggle to come up with any reason other than money for doing what Boeing did. It's really a sad statement on how people behave.
  - philjohn 8y ago
    When you are judged on quarterly earnings results ... unfortunately, yes.
- germinalphrase 8y ago
  It’s been reports that Boeing is looking at a one billion dollar loss due to the grounding these plans. Surely, such training would come in far below this number...
- cameldrv 8y ago
  It's not that simple. I don't believe the unassisted aircraft meets the stick force/stability requirements of FAR 25. Even if it were a completely new type, it would need some sort of stability augmentation to be certifiable.
  - bilbo0s 8y ago
    Meeting FAR 25 is generally done by adding something like hydraulics, or electric engines to assist in moving control surfaces. Both solutions capable of working even in thte case of full engine and power shutdowns. To put an automated system on top of your force assists just seems like asking for trouble. In layman's terms, the more you pile on, the more that can go wrong. All that said, as a matter of full disclosure, I only know how to fly planes, not really an aeronautical engineer.
JSON77 8y ago
you might want to read @GregTravis' article on the IEEE or here: https://www.eetimes.com/document.asp?doc_id=1334482 https://www.eetimes.com/document.asp?doc_id=1334482 which is also on HN. The IEEE is one of the most in depth pieces that I've read on the subject, and this comment by Boeing in this Quartz article: https://qz.com/1603726/boeing-says-there-was-no-technical-slip-or-gap-in-the-737-max/ https://qz.com/1603726/boeing-says-there-was-no-technical-sl... just leaves a lot to be desired.
stupidexecs 8y ago
One thing I don't understand is why is no one is criminally charging Boeing's C-levels. Hundreds of lives were lost thanks to their greed. I say that because everyday at work I am fighting stupid deadlines and ridiculous suggestions to skip QA, unit tests, and other processes to meet those deadlines. If we criminally charge executives when their products cause loss and deaths, then I suspect they will start respecting processes and sane deadlines. Right now, there are no consequences for them. The worst that can happen is their stock options lose some value or they lose their job with multimillion dollar golden parachute. All they have to do is wait a few months and then get another job or start their own business.
nutcracker46 8y ago
Best of luck creating that stall-proof airliner...

72 points by mimixco 8y ago

This windbag proclaimed the swingarm to be unsafe at any speed, but having won plenty of local races with an old beetle, and autocrossed some corvairs, this guy is out to lunch. Sure, the sensor needs a redesign and some automation decisions were hot garbage, but 'never fly again' is just FUD.

simion314 8y ago
>Sure, the sensor needs a redesign and some automation decisions were hot garbage, but 'never fly again' is just FUD. Are you sure that only that except that MCAS all the other systems are fine and Boeing didn't cheap out on other systems, redesigned other things, other small updates etc? IMO the plane needs to be re-approved, this time for real.
- _ph_ 8y ago
  Yes, for sure the whole approval process for the plane needs to be reviewed and repeated where necessary. But if it passed, it should fly again by all means.
  - Chris_Chambers 8y ago
    It already passed once. This is all the information you need to know the reviewers cannot be trusted. Why would you trust the results when it passes again?

jayonsoftware 8y ago

How long before we see "Is my flight a 737 Max " app

vernie 8y ago
Kayak added a filter for it last month.

quantumwoke 8y ago

Isn't the Boeing incident a symptom of poor engineering practices? Spaceships by all accounts seem to have similar if not higher levels of computer-controlled overrides to actually make the damn thing fly past Earth's atmosphere. The difference of course being that spaceship software is rigorously tested whereas Boeing was very lax in their implementation so they could rush the plane out the door. I don't see a problem with the idea of delegating aspects of flight to the computer - just fix the software engineering practices that lead to this tragedy. Please. :)

xiphias2 8y ago
No, there was no technical reason to design 737 MAX as it was designed, only regulatory reason. Regulations should help safety, not hinder it.
- notfromhere 8y ago
  Boeing was trying to build a new plane to fit the technical specs of a previously approved plane to save some cash. Boeing's practice of cutting corners is why 300+ people are dead
  - xiphias2 8y ago
    I agree, I was trying to write the same thing. The body should be redesigned for the bigger engine.
    - notfromhere 8y ago
      The regulatory failure was that the FAA let them get away with it, rather than the regulations themselves.
      - GiuseppaAcciaio 8y ago
        It's an interesting conundrum, because ultimately the FAA doesn't have more engineering expertise than Boeing so all they can do is force Boeing to prove that they have done their due diligence in confirming that the 737MAX can be operated under the same type rating as the 737NG. I'm guessing the next step for FAA and EASA will be to revise the process under which this approval was granted to Boeing.

usermac 8y ago

Read it and agree. I also want to ask if this model is on my flight. Do not want.

exabrial 8y ago

This looks like an attempt to get free press.

vernie 8y ago
This guy's just trying to move copies of "Unsafe at Any Speed", whatever that is.
- nyamada 8y ago
  I'm hoping you're just being sarcastic. I have my problems with Ralph Nader (the 2000 presidential election) but I hope you know because of Nader that automobiles kill far, far fewer people than they did at the time of "Unsafe at Any Speed" (1965).
rcchen 8y ago
There's a bit of a nuance here - his grandniece was killed in the Ethiopian 737 accident [1] so it's personal at some level for him. [1]: https://www.npr.org/2019/04/04/709999296/ralph-nader-calls-for-recall-of-boeing-737-max-jets-after-his-grandniece-was-kil https://www.npr.org/2019/04/04/709999296/ralph-nader-calls-f...
- exabrial 8y ago
  Mmm... didn't know that. I understand _why_ now, but, "never letting the 737 max fly again" is a purely emotional decision that helps no-one. They didn't tear down a 45 story building after the Hyatt Regency walkway collapse, as example. HN is showing a trend of purely blaming Boeing, but there were in fact several failures. Any one of: pilot training [There's a runaway stabilizer trim procedure that's actually a memory item for 737 pilots], not allowing single sensor inputs for flight control systems [FAA spec failure], the decision to allow the MCAS system to command an extreme amount of trim [engineering failure, should have been limited to a sane value] could have prevented the accidents.

patrickg_zill 8y ago

That seems to be premature since, while I respect Nader for many things, his own article points out that the investigations have not yet been completed.

PaulHoule 8y ago

The story that isn't being told is that smaller companies such as Bombardier and Embraer have made the investments in "clean sheet" small airliners that are much better than the 737 in every way. Boeing has used it's market power to keep these away from passenger and airlines. So it's not just a matter of people getting killed. It's people getting killed so you can pay more for airline tickets, have less room and comfort when you fly, have less frequent flights, hear more noise from airplanes, and experience more global warming. As for global warming note also that the 737 has terrible takeoff performance, even under favorable conditions it has twice the takeoff distance of some much larger airliners. Every hot summer you will hear that "airplanes are grounded because of the heat, but really "737s are grounded because of the heat" because the 737 can barely take off as it is. This is what secular stagnation looks like. It is undercompetition and underinvestment, just like we see with wireline internet service in the US. Don't let neoliberals fool you with the "there is no alternative" line because there is.

tiredwired 8y ago
Boeing bought Embraer.
- GiuseppaAcciaio 8y ago
  No it didn't, you uninformed person. The two companies are in talks about a joint venture, but it's not yet ratified because the antitrust authorities in several countries haven't finished their due diligence yet.
droussel 8y ago
Boeing has sued Bombardier to keep it from selling their C-Series aircraft in the US which ultimately led to Bombardier basically giving away the aircraft to Airbus to stop bleeding out money.
sandworm101 8y ago
Bad takeoff performance does not mean a bad airframe. Takeoff performance and things like global warming (fuel efficiency) are often inversely related. No aircraft is perfect at all things. The big wings needed for shorter takeoff during a Nevada summer can mean more drag at altitude. Boeing builds for average customer conditions, not just the special case that is Vegas. (Altitude+heat+dry air = low air density = need bigger wings, bigger engines, and/or longer takeoff roll.)* *There is probably some room here for a joke about how people leave Vegas heavier than they were when they landed.

aglionby 8y ago

The author tells a familiar story of how we got here, but I think misses nuance on what the problem is. It's not the fact that software is used: it works fine normally, but the failure modes were insufficiently considered. > An aircraft has to be stall proof not stall prone. The F-117 begs to disagree.

JshWright 8y ago
Most combat jets "disagree". Most combat jets also have ejection seats for all occupants...
- aglionby 8y ago
  It's not completely fair of me to compare civil jets to combat ones, but in any case I'd argue that ejection seats are perhaps more useful for the other scenarios combat planes find themselves in.
  - JshWright 8y ago
    Most ejections take place due to loss of control, not combat.

jasode 8y ago

I've been curious about some questions that I haven't seen discussed anywhere. HN isn't probably the best place to ask them but since I'm not on any forums where aerospace engineers hang out, I'll just ask here anyway: - Are physics computer simulations (e.g. aerodynamic flow[0]) realistic enough that engineers could have predicted the tendency for the nose to push up into a stall with the forward-mounted bigger engines while still at the CAD drawing stage? (Place some engines on the drawing with X amount of specified thrust, move them forward on the wing, then run a simulation, etc.) Or is the interaction of behavior so complex or so subtle that they had to build the real thing before realizing "Oops, our internal test pilots just noticed the plane is unstable and it looks like we need a software augmentation system!" - Could an unchanged 737-MAX flight simulator from last year reproduce the conditions for the Lion Air and Ethopia crashes? In other words, could a pilot used his/her imagination and said, "What if we make this AOA indicator give a bad reading -- what happens with MCAS?". Similar to how a pilot can choose to simulate a flamed-out engine, could one have chosen a stress-test scenario with a broken AOA sensor? (The infamous deleted video from MentourPilot showed his simulated struggles with turning the stabilizer trim against 400mph aerodynamic loads but it's not clear if a broken AOA can be simulated.) Yes, the 737-MAX was ultimately a failure of management and financial pressure but I'm curious if Boeing even had the technical debugging tools to predict this. [0] examples: https://www.youtube.com/results?search_query=aerodynamics++simulation https://www.youtube.com/results?search_query=aerodynamics++s...

foobarbecue 8y ago
Absolutely and almost certainly.
dsfyu404ed 8y ago
>Are physics computer simulations (e.g. aerodynamic flow[0]) realistic enough that engineers could have predicted the tendency for the nose to push up into a stall with the forward-mounted bigger engines while still at the CAD drawing stage? (Place some engines on the drawing with X amount of specified thrust, move them forward on the wing, then run a simulation, etc.) Or is the interaction of behavior so complex or so subtle that they had to build the real thing before realizing "Oops, our internal test pilots just noticed the plane is unstable and it looks like we need a software augmentation system!" Yes. They knew full well that the MAX would do that in circumstances where a normal 737 would not. There is nothing wrong with the MAX's performance characteristics. The aircraft itself is perfectly safe to fly. What isn't safe is the half baked MCAS system they used to deal with that edge case so they could avoid having to retrain pilots.

flyinglizard 8y ago

“The overriding problem is the basic unstable design of the 737 Max. An aircraft has to be stall proof not stall prone.“ Say what?

_cerv 8y ago
So a blimp?
JshWright 8y ago
The MAX has flight envelopes that are inherently unstable. The plan can get into a state where the aerodynamics of the plane make a stall worse, not better. For instance, the fact that the center of thrust is further forward (compared to other 737s) means that the plane pitches up when you give it more throttle. The default response to a stall is to increase the power, which pitches the nose up, which raises the angle of attack, which makes the stall worse. This inherent instability is why the MCAS was added to the MAX.
- flyinglizard 8y ago
  Not a pilot, but I thought stall recovery is done through nose down first. Turbine engines take some time to respond to throttle up command and thrust on a loaded commercial plane is limited anyhow. An airframe is supposed to have a nose down tendencies upon stalling, which would make it recoverable. The Max may be more prone to stalling, but no one in their right mind would design a commercial airliner which can’t be recovered from stall.
  - JshWright 8y ago
    > I thought stall recovery is done through nose down first Exactly, which is why the nose-up tendency of the MAX is an issue.
    - flyinglizard 8y ago
      Pitch up tendencies under power to my understanding don’t make it an unstable airframe. If you stall, cut power, let go of the controls and the plane responds with a recoverable dive, it’s aerodynamically stable. Some airplanes can’t be (reliably) recovered from stall, that’s another issue altogether.

_ph_ 8y ago

As much as I think that Boeing took the wrong decision when going for the MAX instead of replacing the 737 from ground up and that the way the MCAS was developed and put into operations was a big disaster, both from Boeing and the FAA, as much do I disagree with that article. First of all, while most public know evidence points at MCAS as the source for the crashes, the accident investigations have not concluded yet. The article doesn't even mention that. But, with all what we know so far, Boeing has good reasons to significantly overwork the MCAS software and is doing so. I am not an aviation expert, but from all I have heard about the 737 MAX (from actual pilots), it looks like the airplane itself is not the issue, it was the specific faults in the MCAS implementation and that the pilots were not properly trained on the aircraft. Beyond fixing the obvious issues with the MCAS implementation, the biggest item for bringing the 737 MAX back into business needs to be pilot training. Training both how to fly the machine with MCAS deactivated as well as dealing with the potential failure szenarios of the MCAS system. Of course, the whole certification process for the 737 MAX needs to be reviewed to guarantee that the machine has the level of airworthyness one would expect. This is probably the most time-consuming step on the way to restoring its flight-status, but the most necessary one. Assuming that the 737 MAX after a significant update to the MCAS system passes a proper certification, in contrast to the article I would strongly argue for it to return into service. As much as we know for now, the machine isn't inherently unsafe to fly. But a cancellation could have drastic effects on air travel safety. Boeing decided against a new design in 2011 because of time constraints, and it is now 8 years later. A proper replacement for the 737 MAX wouldn't be ready for many years, probably only at the end of the next decade. If you are worried about safety, you certainly don't want Boeing to rush the development of a new design. Also, there would be little alternatives for replacement. Airbus could increase its output, but that also bears risk of general safety. As does flying the machines, the 737 MAX was meant to replace for more years. So, unless other issues with the 737 MAX are found in review, it definitely should be put back into business.

GiuseppaAcciaio 8y ago
Taking your argument a bit farther: let's assume that indeed the only issue present is a faulty MCAS implementation and that gets fixed. If the aircraft comes with additional training and certification requirements for pilots before it can be safely operated, then arguably it cannot be lumped into the same type rating as the 737NG. This would destroy the main selling point for Boeing (training pilots for a different type rating is a massive expense and headache for airlines), and would also mean that across the world there would be no pilots allowed to fly the existing 737MAX. The point about not cancelling the 737MAX because of the risk that the new models developed would be rushed and unsafe due to Boeing rushing the development of a new design is... not very plausible I'm afraid.

mimixco 8y ago

The key takeaway here is that the public will decide if they want the 737 Max or not. Boeing may have to shift to promoting Embraer designs (which they now own) while it develops a new small aircraft the public can trust, if such thing is even necessary. Public confidence in the DC-10 was destroyed after it had a series of related and back-to-back accidents. The plane was relegated to cargo status and Douglas never recovered financially, eventually selling to Boeing.

dingaling 8y ago
> The plane was relegated to cargo status No, it went back into passenger service and received further orders. American Airlines removed the "DC-10" sticker from the nose and carried on. I flew on the last commercial passenger service of a DC-10 in 2014.

ansible 8y ago

That position in the linked article is a bit extreme. The situation can be easily and safely fixed in software, but it will cost a lot of money. The MCAS system needs to step back to being an advisory-only system, just warning the pilots if it thinks a stall is immanent (and validate sensor inputs too). Then we will need to have extensive pilot training to deal with the different flight characteristics in the 737 MAX. This means a new type rating, which costs time and money... which the MCAS system was created to avoid. But yeah, the system as-is shouldn't be allowed to continue.

blang 8y ago
> That position in the linked article is a bit extreme. This is written by Ralph Nader, taking the extreme position has been his MO since 1965. As far as I can tell he takes a very hard position, in order to try and move the needle of public sentiment.
- sofaofthedamned 8y ago
  Is he wrong?
michelpp 8y ago
> The MCAS system needs to step back to being an advisory-only system, just warning the pilots if it thinks a stall is immanent (and validate sensor inputs too). Then we will need to have extensive pilot training to deal with the different flight characteristics in the 737 MAX. There is already a stall warning alarm on all modern planes and have been for decades. I've only flown Cessnas (which all have stall warning horns), but from what I've read the intention of the MCAS is to reproduce the "stick feel" of an older 737 at high angles of attack and high thrust. The MAX is not "fly-by-wire" it has mechanical cable linkages from the stick to the control surfaces, forces are transmitted in both directions which the pilot can literally feel as resistance to control inputs. Boeing inadvertently changed the feeling of the airplane's response to the pilot. An older 737 would present much more resistance to pulling the plane harder into a stall, the MAX has less resistance. MCAS was intended to provide artificial resistance.

dsfyu404ed 8y ago

Turn off MCAS. Train the pilots on the MAX like it's a new type. Problem solved. This whole problem exists because Boeing tried to use software to fudge how the plain handles in order to avoid expensive retraining. Bite the bullet, train the pilots and the problem doesn't exist anymore. This entire article comes across as though an old man has read something he doesn't like in the newspaper and is suddenly an expert on it in order to justify his outrage when in reality the situation is much more nuanced than his understanding.

bilbo0s 8y ago
You have to wonder why this wasn't done in the first place? Are people really that greedy? You don't want to think they are, but at the same time you struggle to come up with any reason other than money for doing what Boeing did. It's really a sad statement on how people behave.
- philjohn 8y ago
  When you are judged on quarterly earnings results ... unfortunately, yes.
germinalphrase 8y ago
It’s been reports that Boeing is looking at a one billion dollar loss due to the grounding these plans. Surely, such training would come in far below this number...
cameldrv 8y ago
It's not that simple. I don't believe the unassisted aircraft meets the stick force/stability requirements of FAR 25. Even if it were a completely new type, it would need some sort of stability augmentation to be certifiable.
- bilbo0s 8y ago
  Meeting FAR 25 is generally done by adding something like hydraulics, or electric engines to assist in moving control surfaces. Both solutions capable of working even in thte case of full engine and power shutdowns. To put an automated system on top of your force assists just seems like asking for trouble. In layman's terms, the more you pile on, the more that can go wrong. All that said, as a matter of full disclosure, I only know how to fly planes, not really an aeronautical engineer.

JSON77 8y ago

you might want to read @GregTravis' article on the IEEE or here: https://www.eetimes.com/document.asp?doc_id=1334482 https://www.eetimes.com/document.asp?doc_id=1334482 which is also on HN. The IEEE is one of the most in depth pieces that I've read on the subject, and this comment by Boeing in this Quartz article: https://qz.com/1603726/boeing-says-there-was-no-technical-slip-or-gap-in-the-737-max/ https://qz.com/1603726/boeing-says-there-was-no-technical-sl... just leaves a lot to be desired.

stupidexecs 8y ago

One thing I don't understand is why is no one is criminally charging Boeing's C-levels. Hundreds of lives were lost thanks to their greed. I say that because everyday at work I am fighting stupid deadlines and ridiculous suggestions to skip QA, unit tests, and other processes to meet those deadlines. If we criminally charge executives when their products cause loss and deaths, then I suspect they will start respecting processes and sane deadlines. Right now, there are no consequences for them. The worst that can happen is their stock options lose some value or they lose their job with multimillion dollar golden parachute. All they have to do is wait a few months and then get another job or start their own business.

nutcracker46 8y ago

Best of luck creating that stall-proof airliner...