That was disgusting and has me lose the last bit of sympathy I've had left for The Boeing Company.
[1] https://www.inc.com/peter-economy/boeing-ceo-puts-partial-bl...
[2] https://www.ft.com/content/db8a09b8-56aa-11e9-a3db-1fe89bedc...
The second crash may have been avoided by timely application of the NNC procedure for runaway stab trim, right?
"Man if only those "other" victims weren't so dumb, then my favorite company wouldn't have to suffer bad PR!"
Blaming the Ethiopian pilots (One of the safest airlines in the world btw) for getting over speed during the workload induced by runaway trim is disrespectful.
By now, near every professional pilot agrees that these are near unrecoverable events unless you assess and cut the trim in first 15 seconds or so.
Blaming Lion Air in the first hours after the crash, with their somewhat sketchy history, was understandable.
Everything after that is uninformed or racist.
Lion Air as such deserves blame for putting a broken plane back into the air; that's a bigger "third world factor" than pilot error, but it doesn't remove all pilot error from the flight.
The current view is that a mistake by the pilots can not be allowed to bring a plane down. If it does, the plane, software or procedures are designed wrong. And from my experience the industry (at least in Western Europe where I fly) really lives by this.
The fact that the US flies more and has fewer accidents isn’t “racist” nor lucky.
One of these two groups was in posession of a rather importantly wider set of information than the other.
In most major catastrophes/mishaps, there's a number of proximate causes (i.e. the pilots didn't do 'X') that 'could' have prevented the issue. But focusing on these to the distraction of focus on the root cause is a sure way to increase the risk of another failure.
Installing a larger oil pan won't fix your car for long if the root cause is a bad filter design.
> nothing any pilot could have done so close to the ground [2]
FWIW, the pilots in the doomed Lion Air plane on the flight just prior to the accident flight did just that.
There is enough wrong with the 737 MAX, Boeing, the regulatory regime, etc. No need to become hyperbolic and inaccurate.
Not the pilots so much as the person sitting in the jump seat (who suggested disabling electric trim). It essentially took three pilots to save that plane.
The pilots did not know about this problem, they corrected the issue a few time the problem was that after a few correction MCAS corrected extremely and cutting it off at that point was useless because the pilots did not had the physical force to correct the plane.
The other pilots that rescued the situation in the simulator did it by using a technique he read on a pilot forum after the crashes, so it is obvious that a regular pilot that was train using Boeing manuals and followed Boeing guidelines for this problems could not save the plane(at least not in 100% of the cases).
Sure there may be super pilots (like we have super programmers that can read assembly stack traces) or lucky pilots but you don't want to excuse Boeing crimes by the fact that some pilots were lucky.
Agreed, but don't write (as GP did) that "there is nothing any pilot could have done so close to the ground".
It's exponentially easier to recover from a lot of issues, even a stall, when you have 40,000 feet of distance (and thus a lot more time) to play with rather than not even a thousand feet off the ground.
"At 8:39, as the jet reached an altitude of 8,100 feet above sea level, just 450 feet above ground, its nose began to pitch down"
https://www.wsj.com/articles/the-final-minutes-of-ethiopian-...
The third pilot wasn't having to exert 40+ pounds on a control yoke.
The third pilot had a full view of the center console without the burden of having to read and understand a large amount of the information normally considered critical to "flying the plane".
He was therefore in an advantaged position to troubleshoot less obvious root causes of the anomalous behavior.
He didn't know about MCAS, but he definitely got an rueful of trim wheel happily clicking away.
It's why Crew Resource Management is such an important thing, and why people who can pilot have been known to step up and assist crews during emergencies.
Boeing has gone into liability defensive mode at the expense of the lives of passengers, the safety of air travel, and America's credibility in aerospace engineering.
Boeing is either going to face a major reckoning that they may not survive or maybe we'll have more deaths from accidents due to their negligent behavior.
I'm basing all this on the many reports about what is going on around the 737 MAX aircraft published in the WSJ and the New York Times. It hasn't been pretty.
I don't think that plane should ever fly again as engineered. It seems to require software to address problems with the large engine and the plane's form that other jets do not have. If a software patch can make the aircraft safe, then a bug can make it unsafe. Does the FAA validate all the aircraft software patches Boeing issues?
Also, MCAS wasn't put in place to allow the MAX to be type certified w/ other 737s. It was put in place to allow it to be certified at all. It's a hack to ensure the force on the stick continues to increase with increasing angle of attack, which is a certification requirement.
But the expected behavior which MCAS was to provide was not something invented only for "other 737's." Whichever plane would behave as the MAX behaves without MCAS turned on would also be rejected from certification.
Only Boeing being silent about MCAS is the effect of the goal of "avoiding re-certification."
> We don't know
I can't agree to that. Based on the above, I think it is obvious that we do know: 737 MAX without any MCAS-like help is dangerous to fly according to the security expectations which weren't specially invented for 737 MAX.
No, it would have been a perfectly certifiable plane with a particular set of handling characteristics (including 777-like pitch-up). It just wouldn't be a 737, and would require its own type certificate. No-one's suggesting that large turbofan aircraft with pitch-up behaviour are inherently unsafe when flown by pilots appropriately trained and certified for them - otherwise the 777 would be grounded.
It is as long it keeps 737 MAX body and engines and doesn’t have something like MCAS I.e. Inherently unsafe under conditions under which MCAS was supposed to turn on when properly functioning.
The certification requirements are the result of the clear safety goals not something invented “just so.”
The poster you're responding to is right; there isn't anything wrong with the behavior given the right training.
It's just that the investment in that training, and extra certification hoops to jump through would have made WhateveroModelNumberus MAX a non-starter.
It had to be a 737 to work at all.
The behaviour without MCAS on 737 MAX is that minimal movements of pilot’s controls effectively activate what would be considered “amplification” of nose up movement, resulting in an uncontrollable plane and sure crash.
It’s definitely not something that pilots or passengers should be exposed to: being punished for approaching more dangerous position by plane forcing a deadly outcome.
Training pilots to not to move even minimally the controls in the “wrong” direction is maybe technically possible but in practice still totally wrong: It’s comparable to what Boeing told everybody before Ethiopian crash, and their attempts to blame the pilots. In reality, the pilots had almost no chance to rescue themselves and the plane.
In engineering the “positive feedback loops” (amplification of control inputs) are bad the “negative feedback loops” (correction of the input) are good.
The functioning MCAS provides a correction. The plane without MCAS amplification. Badly functioning MCAS also amplification and crash. That's why the wrong behavior was regulated, and that's why it had to be fulfilled for the certification. It’s that easy.
To convince me that 737 MAX without the "properly functioning MCAS" isn't inherently dangerous under higher angles of attack you'd have to provide some explicit proofs.
The FAA certified it anyway. The U.K. gave it conditional certification contingent on the addition of a stick-pusher to be able to operate in U.K. airspace. See the Royal Aeronautics Society D.P. Davies Interview, specifically the 727 one.
There was quite a bit of controversy amongst test pilots at even granting the certification, seeing it as setting a precedent that would lead to a slippery slope that would culminate in less and less airworthy designs.
Nevertheless, the certification authorities accepted the argument that as long as instabilities could be countered by technological means, it would be acceptable.
Let me clarify though, that without MCAS, a responsible pilot would definitely be constrained to a much thinner envelope, but within that thinner envelope, the plane can fly just fine.
The deployment of flaps, also takes the plane out of a regime where MCAS is a factor.
So both legal, and practical precedent for it exists. Given additional training of course.
Boeing 727 was clearly from another times: "As of July 2018, a total of 44 Boeing 727s were in commercial service" "Many airlines replaced their 727s with either the 737-800 or the Airbus A320."
> both legal, and practical precedent for it exists.
Does it? The devil is in the details. Speaking as an engineer, both the measurements of the ranges in which the changes happen and the characteristics of the responses to controls still matter. I wouldn't be surprised that it's still 737 MAX that would be "a precedent" with worse characteristics when the stall is possible (and without proper MCAS-like help) than those measured in 727.
It's the conditions under which the problems occur and the response diagrams that the regulators are supposed to verify, not the binary "has or hasn't" a problem near the stall. I'm quite sure that the technology at the time of 727 introduction was already more than capable of producing the relevant diagrams, so they can be compared. Thanks for specifying your arguments in the answer.
>It's the conditions under which the problems occur and the response diagrams that the regulators are supposed to verify, not the binary "has or hasn't" a problem near the
Ah, I hadn't run into this tidbit before! Can you elaborate on it? I'd love to get some more detailed information if only to facilitate my own deep diving. I've been repeating the 727 simimilarity, and if there's any footwork I can do to make that more accurate, I'd be thrilled to run with it.
I do know Boeing was generally considered notorious amongst test pilots for knowing exactly how their designs would fly, so I can't imagine that those diagrams can't be found somewhere.
To appreciate non-binariness of the problem, just try to find the pictures of different flight envelopes under different flight conditions for different planes and compare them. The wrongness in claiming that every plane can be qualified with just "has x" or "hasn't" is then more than obvious.
Then imagine that you'd actually need the response diagrams -- some valid measurement of how the plane reacts to the controls. That is the actual point of problem: exactly how the curves look like, where are which limits between "fine" and "deadly" and how dangerous is which kind of movement or non-movement of which control.
Then consider that Boeing even after the first crash claimed that "everything's fine" in their "additional instructions" which were followed by the Ethiopian air pilots but that then the plane responses were such that the pilots were practically helpless: the plane "didn't listen." That's what's happening with the positive feedbacks, and that is what "nose up" behavior is -- but the answer is not "yes-no" but where and how much in every point.
The helplessness (or not) of the pilots (i.e. how much of their force produces how much of the outcome under which conditions) is also something that can be plainly measured and drawn.
I don't have the corresponding (complex) pictures of Boeing 737 MAX flying without the MCAS. And I don't think they are available at the moment. But that is the point. Who are those who claim that they know it's safe and what is the basis of their claim? We have already plain demonstration that Boeing openly lied with their "everything's fine" claims -- I can't imagine that nobody inside of a company that is supposed to sell the planes orders of which measure hundreds of billions of dollars has such pictures.
But who can say simple "it's safe" when to be able to really claim it somebody has to evaluate these complex aspects demonstrated by the diagrams and not just construct a simple "yes-or-no-is-it-kinda-same-as-this-other-thing" question?
Reducing that whole topic to such kind of argument "well 727 was bad too" is obviously misleading. The way I still see it is: had it been it actually safe to fly it without a functioning MCAS, there would be no "regulatory requirement" to put it there at all. The "requirement" was an actual "it's not safe without it." But the way that "requirement" looked like was also not "yes no" but "see this diagrams -- the plane should approximately behave so and not the opposite of that." And the opposite is the characteristic of the positive feedback loops. MCAS was there to polish one resulting from the design driven by the marketing goal, not by physics.
Imagine when you would move the steering wheel to make a slight turn and when the car would "listen to you" under e.g. 30 mph but respond in turning you much out of the road when the speed is higher. "Well you should be trained not to try to turn the wheel when over 35 mph" "Really?" "Yes you see that other old car also responded kinda like this one, yes that old one couldn't have killed you so easily, yes, this one will, but don't worry that's actually the same, trust me, because I'm the one making and selling you this new car." "..." That's not how the sameness is compared.
I understand there are different levels of problematic behavoor, because something that causes a 3 degree uncommanded pitch over say 10 seconds is a sight less severe than one that does the same over 3 seconds.
I'm still not seeing anything that's significantly changing my mental model of this problem. Physically, legally and pragmatically speaking.
-The plane remains statically stable within the majority of the flight envelope.
-Dynamic stability still isn't quite there, but can be handled with more conservative maneuvering.
-Critical information was deemphasized in the certification process, or changed after the fact
-the promised deliverable did not achieve it's stated goals without excessive "compliance engineering"
The plane is absolutely dangerous to an uninformed pilot; but aerodynamically, within a constrained flight envelope, it's fine. I don't personally feel it should be airworthy, as I agree with many test pilot's from back in the 60's. It just encourages the use of less airworthy designs with less problematic behavior, because a computer can smooth out the curve, and yet as a programmer myself,I believe a passenger plane should not be reliant on that level of hack necessarily.
As it is, I'm not even highly confident that if there were something wrong with the software update, that the FAA would even catch it in it's current incarnation.
But without language naming the graphs you're talking about, or need to see to be convinced of safety, a FOIA would honestly be fruitless.
Thanks for the contributing though. I'll see if I can find the paperwork.
- of the logs of the measurements of the test flights flown on the 737 MAX prototypes with the new engines but without the MCAS, if the test flights are flown to establish the flight envelope, especially of the correlation to the pilot's input and the plane's response.
- of the calculations or of the physical models of the said response to the pilots input, on the plane without the MCAS. Such parameters and models are indeed used e.g. in the flight simulators.
- Note that even if there were planed deliveries of hundreds of billions (!) worth of 737 MAX planes, up to recently only four (!) flight simulators for 737 MAX were delivered. I don't know if it's possible to even fly them without assuming MCAS "always working perfectly."
I'm not directly in that field to be able to give you a "local" jargon though. My view is a result of just reading those newspaper articles which provided enough engineering details (and a few forums) and I do remember seeing some complex enough related graphs for which I''m sure they couldn't be invented by a journalist, but surely not a "definitive plainly obvious proof". But there is indeed a lot still kept hidden from the public, and I'm sure there are more technical details that are significantly worse than we are ready to imagine.
I am legitimately curious, do you have any explicit proofs of the converse, that (as you say) "the behaviour without MCAS on 737 MAX is that minimal movements of pilot’s controls effectively activate what would be considered “amplification” of nose up movement, resulting in an uncontrollable plane and sure crash"?
The standard should be that a an unimpaired pilot properly trained in flying the aircraft will normally (practically) be in no danger of a "sure crash".
Exactly. And under that assumptions 737 MAX with no MCAS was never certified. Boeing didn't even want to admit that MCAS even exists to avoid even showing the flight characteristic of the plane "without MCAS." It's on Boeing to prove "737 MAX without MCAS" is safe, and up to now they did all they could to avoid that, and I expect they'll do more of that unless there is a pressure outside of both Boeing and FAA.
So it seems to me that the discussion in this subthread is really around that point: could the aircraft have been certified as a new type without the horribly dangerous MCAS system in place to paper over the change in flight characteristics?
You seem to be saying no, and the other guy says yes, but you seem more to be talking past each other than offering proof of your assertions. He at least did point out (though without citing any proof, I think) that the 777 had a similar issue and was certified anyway (and I don't believe 777s have been falling out of the sky because of it). But, obviously, this is a different aircraft.
Also, lots of planes require software to be safe to fly. It’s just the way things are nowadays.
Hence, the government is unlikely to deal Boeing a killing blow.
But yet, even after the second crash Boeing still insisted they continue to fly the plane. It's like they pre-determined their decision and any evidence or additional crashes be damned.
I don't want to have too much hindsight though - if the AA pilots union really didn't want to fly the plane, presumably the union could have chosen not to fly the plane (I think it's in most pilots contracts?). In fact, even after Ethiopian crash, American pilots continued to fly the plane. Though part of this may have been because they didn't have the full amount of information Boeing did.