The difference with AF447 was that the aircraft at no point was defective, it was purely confusion on part of the flight crew and the issue with two pilots "in control" which the Captain absolutely should have dealt with.
But that's not what made me nervous about Airbus. Rather, that's when I learned that Airbuses are flown by side-sticks that aren't mechanically linked while Boeings are flown by yokes which are.
The advantages of fly-by-wire are too good to pass up, so that leaves the question of how to design an FBW system.
A high school teacher of mine in the 1970s predicted an accident like AF447. He framed it this way: the 'American' approach is to implement FBW to always do what the pilot inputs indicate, whereas the 'French' approach is to do the right thing, and override the pilot if the FBW 'knows' better. That's an interesting cultural cultural consistency as well!
So, the 'American' approach is better if the sensors are not working as expected, and it makes the software simpler. The 'French' approach is better if the pilot is wrong, but both the sensors and the software must be working perfectly. Everyone makes mistakes, and all software has bugs. What to do?
(In reality, some 'judgement' is needed by the software, even in the American approach.)
EDIT: That said, some of the design choices in the Airbus FBW are baffling, such as making the control input the average of two different inputs. I like to think AF447 is less likely to have happened in a Boeing ship, although the ulitimate cause of the crash was a pilot making what amounts to a beginner mistake.
None of this is relevant to the actual issue raised by the GP: the yokes of the pilot and co-pilot are not mechanically linked. They can be mechanically linked even with a FBW system. And personally, as someone with a bit of flying experience myself, I can't comprehend why you'd want them to not be mechanically linked. The opportunity for confusion with conflicting inputs is too damn high.
Mechanically linking is heavier than fbw/electrical/fiber optic linking, and what's the point if there's no mechanical linkage to the control surfaces?
With the fbw system, the software makes the choice on how to interpret the control movement, use one or both? If one, which one?
EDIT: Maybe you mean that a mechanical linkage would provide a feedback mechanism, so that one pilot would know if the other pilot was attempting an input? I don't know if there's force feedback on Airbus flight controls.
> what's the point if there's no mechanical linkage to the control surfaces?
In this case, the pilot would have realized the junior copilot was issuing control inputs and (likely) prevented a plane from crashing, saving the lives of all aboard.
Seems like a pretty decent point to me.
> EDIT: Maybe you mean that a mechanical linkage would provide a feedback mechanism, so that one pilot would know if the other pilot was attempting an input? I don't know if there's force feedback on Airbus flight controls.
Yes, that's what I meant. And no, there isn't. At least, not one that would indicate conflicting inputs from the other pilot.
> although the ulitimate cause of the crash was a pilot making what amounts to a beginner mistake.
But it was only one of the pilots, the right-side pilot, who continued to hold the stick back and and retained command. The left-side pilot didn't realize that was occurring until it was too late.
Indeed, but you'd definitely notice (unlike on the Airbus). Furthermore, if I'm not mistaken, you'd then have a split elevator (one side up, one side down), while the Airbus just averages the two inputs and sets the elevator there, conceptually.
I’m not a pilot. I’ve just read the Wikipedia page on this crash and the final report. I don’t know what is common or expected and planned for but I take your characterization to mean that you think that it’s not a significant problem.
There’s three pitot tubes. There were ADs issued over them icing over. Airbus replaced them multiple times with tubes from different vendors.
In the final report, the first major issue is “Temporary inconsistency between the measured speeds, likely as a result of the obstruction of the pitot tubes by ice crystals, caused autopilot disconnection and reconfiguration to alternate law.”
Icing over of pitot tubes seems more significant to me than I think you’re making it out to be.
It really highlights how terribly trained the pilots involved are - temporary inconsistency in measured speeds (there are still plenty of reasonable speed sources) in almost all other planes does not result in the plane crashing. Heck, my GPS can do groundspeed easily enough and you have basic pitch and power settings.
How did they not notice their altitude was climbing as they pulled the plane up - they got into a CLIMB rate of 7,000 feet per minute - that's STUPID! WHY climb like that? This has nothing to do with airspeed.
The stall alarm goes off 75 times!
They reduce power to idle for a bit??
It's total nonsense, anyone who has flown a single engine cessna for 200 hours or more would have been able to get out of this easily just based on stall buffet and stall alarms.
I'm not sure what accident you are talking about but the MCAS in the 737 Max overrode pilot input. The real problem was that pilots did not know that the MCAS existed, nor did they know how to disable it.
I won't fly Air France, not just because of AF447, but also the time they diverted into an airport in the middle of a civil war and had a whip round in first class to pay for the gas to get out of there.
I won't fly Air France because they cost me 500 euros for nothing. I was in Paris and set to leave and they went on strike. I waited in line for hours to try and get on any flight out, and they said there was no chance I would leave that day, and I should book a hotel.
So we booked the cheapest thing we could find that would work with our baby, and it was 500 euros for the night. Two hours later they called us and told us to get to the airport right away if we wanted to leave France in less than a week.
So we left France on small plane, and couldn't get a refund on the hotel because it was less than 24. All because they couldn't figure out how to get us on that flight two hours earlier when I was at their customer service desk.
I can understand why but a part of me is left thinking, what an adventure that could have been. Sitting around over a drink and telling your story of the time you got caught up in the Syrian Civil War.
The stall warning stopped when the plane was too far into a stall to consider the data valid. I’d say that’s a malfunction for usability. It caused the pilot to keep pulling back because that stopped the warning.
It was controlled more by pressure than movement, using joysticks instead of the traditional huge yoke. When one person was screwing up, the other could not observe this. On a Boeing, each person would feel the other person's force because the controls are physically linked.
The stall warning was designed for mild stalls, not severe stalls, and would turn off if the stall was really bad. They got into that state. Every time they reduced the stall, they would get back into the range in which the warning would alert. This caused them to go back into the worse condition, in which the stall warning just gave up.
The pitot tubes, used to sense speed, were prone to clogging with ice. Better equipment is expected on a large passenger plane.
That's all the aircraft itself. If you want to blame the pilots for any of that, then Boeing can rightly say the same for 737 troubles.
That's a "you're holding it wrong" argument. There are always human factors, no matter how well trained. So while the errors these pilots made shouldn't have happened if they were better trained, at least one of the errors, fighting over who was controlling the plane w/o realizing it, is impossible in a Boeing cockpit.
No its not. The point of these reports is to get to the "primary causes" of the accident and include design decisions that contribute to an accident.
These are trained pilots who did not follow their training. They didn't follow procedures that were in place for these types of events. They did not follow cockpit management procedures. They didnt know how to properly deal with stall conditions, a fundamental piloting skill. They managed to crash a airplane that was flying perfectly fine.
I don't understand the fixation on the sidestick. Its not like they just tossed it in there. Thousands of engineer hours were spent creating the systems to manage control inputs. It may have been a contributing factor, but the sidestick isn't even mentioned in the proposed improvements section. This was pilot failure.
The thing is, in all aircraft (very much including this Airbus), there are procedures you're supposed to follow for certain failure conditions. They're generally in something called the Quick Reference Handbook, or QRH, but there are also simple flows that crews are supposed to be trained for. One thing that is key in this situation is to announce "my plane" if you are the one flying...which never happened. The Airbus also has a button to mark sidestick priority, removing the other pilot's inputs entirely. That also was not used. No, one part of this (holding the stick full back) could not happen on a Boeing, but the rest of it sure could.
The thing that personally scares me is not Airbus' take on how to fly planes, but rather Boeing's current take on the 737MAX where things are physical controls, kinda, somewhat, unless they aren't and become fly-by-wire. That's the issue with the MAX: if they'd been willing to train pilots for the new dynamics, rather than try to mask it with MCAS, it'd be fine. If it were fully fly-by-wire like an Airbus, it'd be fine. But the halfway house confused everybody on board.
Because humans screw up all the time. They are the weakest link. You can have the best damn plane and it only takes one guy or gal to drive it into the ground.
The difference between the Boeing problem, where the computer would do un-intuitive things that caused the planes to dive, and the AF447 A330 situation, where the pitot tubes froze over (they shouldn't have) but the aircraft wouldn't try to crash itself, is significant.
Of course the pitots shouldn't have frozen over, and of course the stall warnings were poorly thought out, and of course the lack of direct awareness by the other pilot of Bonin's inputs leads to misunderstanding of the situation, but there's one big problem in the AF447 case that has nothing to do with bugs in the A330.
Bonin (who flew the plane into the ocean) had no awareness of the Airbus's different flight modes or that the autopilot disconnect meant the plane was in Alternate Law, and as a result blissfully kept pulling back on the joystick thinking the computer would save him from ever stalling. The different flight modes are like the most basic part of operating an Airbus in an emergency, and the idea that any trained pilot wouldn't first consider which mode they're in is staggering.
Read the transcript. You have Bonin pulling back on the stick almost continuously without saying so, you have Robert advising him to descend, and Bonin replying that he was descending, when he never did. He let the controls go back to neutral, the plane was still ascending with a wildly high AOA for the conditions, and he quickly reverted to pulling back on the joystick.
Only less than a minute before impact, when the rapid descent and confusion lead to Robert advising Bonin to climb, does Bonin reveal the critical information, at which point both Robert and the Captain must have been shocked and horrified, both realizing they had to dive and also realizing they didn't have enough altitude and were going to crash:
02:13:40 (Robert) Climb... climb... climb... climb...
02:13:40 (Bonin) But I've had the stick back the whole time!
[At last, Bonin tells the others the crucial fact whose import he has so grievously failed to understand himself.]
02:13:42 (Captain) No, no, no… Don’t climb… no, no.
02:13:43 (Robert) Descend, then… Give me the controls… Give me the controls!
[Bonin yields the controls, and Robert finally puts the nose down. The plane begins to regain speed. But it is still descending at a precipitous angle. As they near 2000 feet, the aircraft's sensors detect the fast-approaching surface and trigger a new alarm. There is no time left to build up speed by pushing the plane's nose forward into a dive. At any rate, without warning his colleagues, Bonin once again takes back the controls and pulls his side stick all the way back.]
02:14:23 (Robert) Damn it, we’re going to crash… This can’t be happening!
02:14:25 (Bonin) But what’s happening?
02:14:27 (Captain) Ten degrees of pitch…
Exactly 1.4 seconds later, the cockpit voice recorder stops.
Bonin may have passed training but he clearly wasn't competent to fly an Airbus. Air France crew resource management (communication between pilots) sucked, and a bunch of Airbus quirks led to the other pilots not discovering that Bonin was doing the wrong thing until it was too late. However, virtually any other pilot wouldn't have stalled the plane.
It seems like the difference here is that in the Boeing incidents the flight computer was Bonin, inputting the grossly wrong control[1] based on a tragically flawed model of the current angle of attack. Among all Airbus pilots, there are probably only a small number of Bonins. On the Boeing 737-MAX, every plane has a Bonin.
[1] Not just the wrong command, but of a magnitude that greatly exacerbated the situation, based on an unwarranted level of certitude.
I guess it depends on exactly what point we consider the state of flying to have ended during a crash. The second the plane first makes contact with the ground, or after all of the fragments stop moving?
I think it comes out in favor of flying either way, but for sure the second makes it pretty lopsided. It limits the possibilities of OnPlane && !Flying to waiting for takeoff, and since you spend more time in the air than grounded even death by natural causes in flight would overtake death while grounded.
Almost all airline accidents in modern days are "freak" accidents, but I personally consider AF447 one of the freakiest of the freaks. The long wait to figure out what was wrong probably amplifies the feeling.
I'm not an expert but I do watch aircrash investigation and many of the accidents are caused by mistakes from pilots, airtraffic controllers and or mechanics.
Thats why this crash bothers me. A design flaw in a production aircraft is not something you expect in the modern age.
Maybe you should re-watch the episode :) . This was much more than a "design flaw". There was an issue with the pitot tube design, but it was enough to bring the airliner down like a rock.
A combination of route planning, misunderstanding of what is happening, CRM, poor UX, and at the end, incompetence were also a factor.
This is the natural conclusion to decades of corporate lobbying, revolving door political appointments with overt conflicts of interests and regulatory capture. Those with financial incentives get control or massive sway over oversight. In the short run, I'm sure it's to a corporation's advantage, other corporations follow suit because, hey CorpX is doing it. Before you know it, and often suddenly, no one trusts anything. Oversight and regulation sucks when the process feels onerous on you but they have a place in society.
Airbus’ problem is overinvesting on the A380 and getting rid of it.
Boeing’s problem is having integrated a company who was repeatedly found to have FAA collusion, and having repeated their schemes, resulting in their 2013 airframes and in their Max 8 engineering based on broken FAA supervision.
Comac’s problem is being the young inexperienced incumbent, but worth noticing with its Asian future.
Yeah the way everyone is treating this as a technical problem instead of a corporate culture problem make me wary of repeats. You’re not fixing the root cause
Spirit, Frontier, American, United, Delta, JetBlue; i'm sure I'm forgetting a couple. The only airlines that are exclusively Boeing are Alaska Airlines and Southwest.
Most legacy carriers globally have ended up with some of both Boeing and Airbus.
Just anecdotally (and I expect this doesn't hold statistically), I don't even notice a difference in manufacturer distribution between these US and EU airlines.
While it's probably true that they fixed the software to never again produce this kind of error, I don't like the idea of software being used to correct the fundamental physics that the airframe is dynamically unstable. While the software probably does a good job of correcting it under a wide range of normal operating conditions, can it deal with evolving or abnormal operating conditions? Will the software still be able to compensate if the pitch-up moment is artificially increased by, e.g. the roof turning into a scoop, or flaps jamming, or a small piece of wing trim breaking? Would Aloha Airlines Flight 243 still have landed safely after the roof came off, becoming a scoop, if it were instead a 737Max?
737MAX is not nor never has been dynamically/aerodynamically unstable. Full stop. No airliner is permitted to be unstable by FAA regulations. At no point in the flight envelope will the aircraft pitch up into a stall without pitch-up inputs, thus it is not unstable.
MCAS was used to augment flight stick characteristics, namely to simulate a linear relationship between flight-stick input force and pitch-up/AoA. This was, and always has been, about single-certification and pilot UX, not anything about the stability of the airplane. Having stick forces be somewhat lower than expected at high AoA does not make the plane unstable. The linear relationship is considered ideal, but many planes such as the 757 have a similar non-linear relationship. MCAS is not anti-stall.
Granted, this has widely been mis-reported. The real issue is that the MCAS system was made dramatically more powerful, and thus dangerous, over the course of development. Without a concomitant change to the reliability of MCAS inputs (namely the AoA sensors), this resulted in disaster.
>737MAX is not nor never has been dynamically/aerodynamically unstable. Full stop.
Correct in the jargonic sense. Incorrect in the colloquial. MCAS was necessary because the MAX was not compliant with Stick force response curves in high AoA flight regimes, and would experience a reversal in the pressures required to bring the plane up to a stall.
So yes, it was not aerodynamically unstable, but in the layman sense there is an instability or undesired quirk being compensated for.
I know we're all pedants here, but lets be productively pedantic.
Wait, wasn't MCAS used to fix two completely different flying issues, and weren't the changes introduced in the MCAS software twice, for two different points in the flight? Wasn't at least one crash caused by MCAS activation in the phase of the flight that was not even described in most of MCAS explanations initially (which reflected the decision behind the initial introduction of MCAS, not the later modifications)?
Therefore I believe the interpretation that MCAS "just augments" is too simplified from what it really was supposed to do. And the current "fixes" as they are implemented (still as to keep the "water not wet" there) could still leave plane as not behaving as it should, neither with MCAS active, nor when it is not active when it was supposed to be.
MCAS was introduced to handle slackening Control surface response force at high AoA in high speed high AoA situations (Wind-up turns) and low speed high AoA situations (generally landing). That type of slackening would normally disqualify an airframe from use as a Civil Transport aircraft according to the FAA final report on the matter.
I've said this elsewhere in the thread, but stabilizing a dynamically unstable system is half of the reason why control theory remains an active research area instead of a mathematical backwater; this kind of set up is extremely common for aerospace systems. Software is hard to get right - which is why aerospace software has traditionally faced much higher bars for verification than 'traditional' software (and is much more expensive as a result!) The same is true of hardware, which I think many HN commentators forget; the cost of a bolt or connector that is aerospace-grade is typically many times that of a conventional or automotive-grade part, due mostly to extensive testing+verification required for safety.
Most of the scenarios you're describing are dealt with in a few ways:
1. Building systems with sufficient margin to account for this kind of uncertainty; even with passively stable aircraft, these margins exist. Feedback control typically increases these margins.
2. Extensive verification under a wide range of input conditions; this is more challenging (how can you enumerate every possible failure condition?), but usually boils down to some kind of Monte-Carlo sampling or worst-case analysis when those cases can be identified. Here's [0] a neat paper that does this in a more sample-efficient way.
I was under the impression that this was never a software problem, just that they are attempting to fix the problem with software.
If you get a faulty AoA sensor, or maintenance installs it poorly, there is nothing the software can do to fix that.
The problem was dual AoA sensors were sold as an additional feature instead of a base requirement.
Since the problem was not caused by software, the best you can do with software is to try and build some workarounds.
I think the only way to fix this with software would be to use the other AoA sensor from the secondary MCAS, making the backup system no longer fully redundant, but that's just a guess.
Would be interested in feedback if this is accurate.
At any rate, the software will never be 100%. The biggest change in regards to safety is that pilots are now aware they can turn the MCAS off. Which is the necessary knowledge that would have prevented both crashes.
737Max is certainly tainted now. But will that last forever? And do non-HN-aviation-geek consumers really care enough to check the model of the plane they'll be flying on, let alone make a flight decision based on the model?
Certainly another crash could be devastating to the model.
But was the 737Max a poorly designed death trap rushed to production or a super safe airplane with a single fatal flaw?
Unless, of course, it was fixed and scrutinised by organisations which still have the same systemic flaws as the first time around.
Until the sociotechnical systems that do the work change, they will keep overlooking problems and making similar mistakes, from a high-level perspective.
Do you mean the same regulatory organizations that have reduced the US airline fatality rate by 50x over the last 50 years to the point where it's now over 100x safer per mile to fly than to drive?
I mean the FAA certainly has some flaws, but it's important to keep things in perspective.
A caveat here is that the modern FAA is very different than the FAA of even 20 years ago. In response to decades of stagnant funding, 'the beast' is fundamentally unable to fill the same regulatory role it was intended to do - to all of our detriment [0].
I think the passenger miles statistic is baloney (calculated by multiplying the number of passengers by the number of miles travelled), and I'm a bit sick of seeing it trumpeted everywhere to claim flying is vastly safer than driving. The collective risk of everyone on board the plane is meaningless to calculating risk to your personal safety. At least for me, the fatality rate per journey, per hour of travel, or at the very least per mile I myself am travelling, is far more relevant. According to one source, flying is actually three times deadlier per journey than driving (fun fact, this is the metric aviation industry insurance companies use), but about four times safer per hour travelled. So flying certainly can be safer than driving in the right context, but these crazy "100x safer than driving" stats are kinda useless and take a lot of "creativity" for airlines to arrive at.
source: https://en.wikipedia.org/wiki/Aviation_safety#Transport_comp..., citing Beck, L. F.; Dellinger, A. M.; O'neil, M. E. (2007). "Motor vehicle crash injury rates by mode of travel, United States: using exposure-based methods to quantify differences"
Maybe because the choice I make as a consumer isn't between going to Hawaii by flight or by car -- it's whether to make a plane journey to Hawaii or a car journey upstate.
So maybe per total hour from door to door is the relevant metric: you tend to make decisions based on comparable travel times, whatever the reason for travel or mode eventually selected.
Don't get me wrong. If I'm going to trust anyone to learn from their mistakes, passenger aviation are the ones.
I'm just saying that when it comes to complex systems, it's not evident that someone who said "I've looked at it and it checks out", the thing fails, and then the same someone said, "Okay, now I've really looked at it and it checks out again" that it's now safe. There's more nuance to it than that.
Whether or not that nuance has been taken in consideration by the FAA this time I really am not in a position to say.
> Do you mean the same regulatory organizations that have reduced the US airline fatality rate by 50x over the last 50 years to the point where it's now over 100x safer per mile to fly than to drive?
As a layman, per-mile normalizing of the safety statistics feels wrong to me, given the speed and distance disparities between car and air travel (for many trips, the two modes aren't really substitutes).
IOW, 100x safer per mile doesn't look as good when contemplating a plane trip 200x longer than your daily commute.
I'm not sure what would be best, but either time-based or per-flight normalization seem like they would be an improvement. Or perhaps per-person (eg. x people fly per year, y have been in an accident).
To be a bit more nuanced, it's not that the engine placement was the problem, rather it was that Boeing made software adjustments to make the plane fly like a regular 737 without training the pilots in these changes.
> rather it was that Boeing made software adjustments to make the plane fly like a regular 737 without training the pilots in these changes
No, this is a persistent and pernicious myth on HN – that the MCAS was some sort of “737 Emulator” intended to allow the plane’s customers to avoid pilot training.
In reality, during testing it was discovered that the engines’ new position caused the stick forces to invert in some situations during flight. “The stick forces invert” means that it becomes easier to pull into an aerodynamic stall than push away from it.
This fails a Fundamental Airworthiness Requirement that all commercial aircraft are required to conform with for certification.
Boeing’s “solution” was MCAS – using the stabilizer trim to automatically push the plane’s nose down as it approaches a stall (and therefore putting additional force on the stick that keeps it at all times easier to push away from the stall than pull into it).
The pilot training thing was just that they concealed the existence of MCAS from pilots out of fear that it would prompt calls for additional training.
tl;dr the problem was that the engine aerodynamics made the plane fundamentally uncertifiable without a software hack.
The fundamental problem is a lack of effective redundancy for bad sensors. They haven't fixed that. Software alone will not fix it. They've just implemented superficial procedures that don't address the real safety issue.
It is methodologically unsound. The airframe is unstable. The fixes are software and training, human factors engineering, and hence don't address the underlying problem which is one of physics. I am sure that the measures taken will reduce the rate of crashes, but doubt that they will eliminate them, as you can't exclude effects without first excluding causes.
In my experience the non aviation geeks are also worried about 737 Max’s.
That’s validated by the fact that the involved companies are referring to it as the 737-8 instead, which will not fool anyone who knows anything about aviation and is geared entirely towards ordinary people.
There's already the 737-800. So you're saying companies flying the Max may have in their fleet both a 737-800 (aka the "738"), and what they're now calling a "737-8"?
Not an aviation geek. You'd be surprised how nitpicky people will get when it comes to their family's safety. Between when the MAX problems came out and the fleet was grounded, I cancelled my family's vacation at substantial cost and inconvenience because the airline had 737Maxes in the fleet and I saw that my flight had been flown by Maxes previously.
How many people actually look at what plane they're meant to get when they compare times, dates and prices for their booking? Let alone what plane is actually at the boarding gate 6 months later...
I bet more than a few traders looking for an edge are trying to find someone who works at Kayak to tell them how many more clicks there are in “see full flight details” before purchasing a flight there are now.
Thats great. But then when you get to the gate and there is a 737Max sat there waiting for you, do you board? Or do you accept that you won't get a refund and now need to buy another flight and just hope there is one today for an affordable price with a seat not on a 737Max?
Consumers aren't exactly helpless here. The worst-case scenario is the customer is unable to get another flight (for whatever reason) and 'has to' board the 737Max that one time. The customer can then choose not to book with that airline again. I'm already not a fan of AA, and with this news I can happily avoid this situation by simply not flying AA.
Will I always feel this way? We'll see. I'm fine with letting other people be volunteer guinea pigs before I commit to something.
It would be interesting to see how elastic demand is for this factor. I guess it depends on how easy it is to book the same flight with another airline who don't use 737Max vs how much of a discount the airline can get for using them (plus passenger numbers and what proportion care and how effective a rebranding they can run etc).
except at least initial the airlines will probably accommodate the people who don't want to get on the plane because it is a Max. Better a little problem of rebooking, than social media posts that will remind people hey they are forcing you on a death trap.
Whether it is or not, best not bring attention to the fact you might be flying on a Max.
That's fine as long as there is a flight between the same 2 destinations with the same airline in a few hours that doesn't use a 737max.
If not then what?
I can see the 737 being pushed to infrequent routes with minimal competition. If you want to fly from Fairbanks to Springfield, it's the 737 or nothing and you either fly now or wait 4 days for the next flight (or pay 8000usd for a 19h, 4 leg super combo...).
Was thinking similarly. I don't think there's any guarantee you'll get the particular plane model that is scheduled. Maintenance or other factors may mean model X is unavailable, and they substitute model Y instead. You've contracted to get from point A to point B via plane, that's typically it.
Was the article pounded together by an overworked, exhausted and underpaid reporter, or put together by some kind of summarization/content generation algorithm? That is the question.
Is there any way to know what kind of aircraft you'll be boarding when purchasing tickets? I've never paid attention until now, and the 737-Max is definitely a non-starter.
Just curious, what would it take for you to get on a 737-Max?
European and American regulators have gone over it with a fine tooth comb at this point and allow it to fly. There is always gonna be people that will say the plane shouldn't fly. Arguably the amount of attention this plane has gotten will probably make it one of the safest in the industry going forward.
Nothing more than approval by relevant authorities. Once I use a different treshold than that, it becomes very difficult to fly at all.
I mean all else being equal (Two planes to London leaving at almost exactly the same time and exactly the same cost) then perhaps I'd prefer the A32X. But the point is all else isn't equal. It becomes a matter of how many hundred you want to spend to fly the Airbus. Or how many hours you want to spend at the airport waiting for the non-Max flight. And I'll happily take the MAX if it saves me 30 minutes or $20. And I'll take my family along too without hesitation.
The whole thing has been badly handled. The FAA/EU agencies should have declared at the very outset that airlines will need to bear the cost of retraining the pilots who will be flying this. It was the attraction of not having to retrain pilots that was the biggest incentive for Boeing to pull the shortcuts they did. At a bare minimum the aviation agencies should have pulled that benefit away.
No it is not. No regulators has yet been prepared to certify a fixed-wing aircraft that is intrinsically unstable, even after decades of proven fly-by-wire development.
The 737 Max has different yoke force during pitch-up than predecessor 737 models, such that at higher angles of attack it does not natively require increasing yoke force to continue to pitch up. That doesn't mean it would pitch up uncontrollably. MCAS was designed to provide pitch-down force in these high-AoA cases so that yoke forces would be equivalent to 737 NG models and minimal training would be necessary to fly both.
https://en.wikipedia.org/wiki/Relaxed_stability#Unstable_air... indicates that the MD-11 (which regulators certified) is aerodynamically unstable. (That plane has a compensation system, similar to the 737-MAX.) Is "intrinsically unstable" different from "relaxed stability" in some subtle way?
And while military planes are quite different from commercial planes, many (most at this point?) military jets are aerodynamically unstable.
There are different kinds of "relaxed stability", largely depending on which axes of the aircraft are affected, and the magnitude of the instability.
Longitudinal stability is something of a special case, in that essentially all swept-wing aircraft are vulnerable to "Dutch roll" instability and are generally fitted with yaw dampers. Since such stabilizers are, practically-speaking, omnipresent, regulators are OK with using them in what is now a well-understood domain. While it can be unpleasant, all of these aircraft can be flown with a failed yaw damper - notably the 707 family has a particular proclivity for yaw instability, and while almost all civilian users opted for the yaw damper, the largest fleet user, the USAF, did not fit their KC-135s with dampers until well into their service life.
For good reason, pitch instability is a much more serious issue, and there has been very little interest in trying to bring to market a transport aircraft that required active pitch stabilization. Many, if not all, modern clean-sheet airliner designs are fly-by-wire due the the safety, performance, and efficiency improvements to be had, but they are all safely flyable in an "alternate law" (or equivalent) fallback mode.
Combat aircraft, generally speaking, aren't certified aircraft (they have no need be), for good reason - if you're flying a modern fighter and the FBW computers die on you, it's over, you eject. Understandably, that's not an option in a transport aircraft.
Aerospace controls engineer here - while the airframe might not be passively stable (as is common for civilian aircraft), dynamically unstable aircraft have been stabilized with control software since the 70s [0]. If you've flown on an MD-11, you've flown on an 'aerodynamically flawed' aircraft. Most real systems are dynamically unstable without some kind of controller (implying software) in the loop.
Ah - I didn't say Boeing's ability to write and test that control software was particularly good (in fact, I think their current track record says exactly the opposite.) I just hate when non-domain experts make judgements about things being 'fundamentally flawed.'
Insufficiently tested and documented? Sure. Bad UI/UX? Most definitely. Irredeemable 'because of aerodynamics' according to some private pilot that flew a 737 once in sim? Absolutely not.
But yes. MCAS was put in place due to concerns over aero. If that was just to avoid the need for extra pilot training then it should have been scrapped since new training will be required now anyway. But since great effort has been made to fix MCAS we can conclude that the root problem is aerodynamic.
Can aerodynamic issues be compensated for with software? Sure. I need to read up on the final hardware/software/instruction solution before passing Judgement.
You're completely ignoring that flying the 737 MAX without MCAS is not an automatic death sentence. Meanwhile a malfunctioning MCAS is actually an automatic death sentence.
The big flaws are in the software, not in the hardware. So stop focusing on that.
It’s “atypical” because it’s a 30+ year old superseded model and there are more efficient designs available. KLM, a flag carrier, was flying them up until just a few years ago. If it’s certified for carrying passengers, it’s certified. There are no special concessions made to airworthiness regulations for aircraft that sell few in number.
The MD-11 has been certified for air transport since it was introduced, was flying in revenue service until 2014, and as far as I know, that certification has never been revoked.
I don't think the flight safety record of the MD-11 bears that out[0] - most crashes of significance were either cargo flights (which are much more prone to dynamical issues than passenger flights) or flights in conditions that exceeded design specs (landing in typhoons). It sounds like most airlines sold it because it missed range/fuel burn targets, not because of safety issues.
My Dad was a frequent business traveller in the 1980s and 90's and I remember him commenting on the MD-11 and saying that he hated them because they were noisy and had lot of vibrations at the back from the center engine.
He said that was the the reason airlines switched to using them as cargo planes.
>Travis is unequivocal in his assessment of the Boeing 737 MAX. “It’s a faulty airframe. You’ve got to fix the airframe [and] you can’t fix the airframe without moving the engines” back and away from their current position.
>The root problem with the engine-forward design is “once this thing pitches up, it wants to keep pitching up,” said Travis. “That’s a big no-no,” he continued, because pitch-up on an aircraft increases angle of attack.
"Gregory Travis, a veteran software engineer and experienced, instrument-rated pilot who has flown aircraft simulators as large as the Boeing 757"
I know a few veteran software engineers that are instrument-rated and frankly I'm not sure I would listen to any of them over the FAA or aeronautical engineers. Probably good for some perspective, but not exactly a great source for determining if an airplane is "aerodynamically flawed by design".
That article, and Gregory Travis' assessment, offer zero actual evidence that the design is unstable. Lot of hand waving and "the engines are different so it must be dynamically unstable" but no actual evidence, which is obvious because no independent engineer/pilot is going to be able to effectively assess the upset aerodynamics of an airliner and come to a different conclusion than both the FAA and EASA about whether or not the aircraft is dynamically unstable.
He's somewhat right on other details, but that doesn't make his assessment of the aerodynamic issues correct.
I suppose it boils down to whether you have confidence in the FAA of 2020 to make a decision that would be strongly against the financial interests of Boeing and many US carriers.
I think the Max will crash again. Excuse me, the 737-8 will crash again.
If pilots can disable the malfunctioning MCAS during emergencies then this type of accident won't happen again. The 737 max might suffer from more emergency landings than usual though.
Every airline will show you the scheduled aircraft when booking tickets, usually right next to the airports and travel times. Nothing guarantees they won't change it at some point before the flight though.
The short answer is no. The longer answer is that you can see the planned type of aircraft when you book your ticket which doesn't typically change. But airlines can and do sometimes switch aircraft types at the last minute up to the point where you're already at the gate.
ADDED: And I'm guessing things are more fluid than usual in the current situation.
It really depends on the route (and the airline). Some routes I've flown are scheduled for different types throughout the day; it's not uncommon to fly on the other type. As a bonus, different types have different premium rows, if you reserve a non-premium seat and the type is changed, you may keep the seat number and get a premium seat.
If I saw 737MAX pulling at the terminal I would have cancelled the trip, but usually airline shows plane at itinerary and you can check flightradar what planes fly that route.
IMHO, the 737Max should be forced to serve in non-passenger service - e.g. courier shipping - for a number of cumulative flight hours (e.g. 5,000) before it goes back to passenger use.
Given the huge rise in shipping during the holiday season this criteria could be satisfied by the end of the year.
,,The announcement comes even though Boeing is yet to implement a software upgrade that his agency demanded. It could be two years before it’s ready.''
It's not like it's impossible to make the 737 Max safe but the problem is that Boeing took shortcuts and how can we trust them to not have taken shortcuts again?
My friends who have recently flown American have all complained how shitty American's COVID precautions are. Bringing the 737Max back isn't going to change bad service.
I suspect that after this year, with 5 737Max's worth of people dying a day, that this plane now falls into the "acceptable risk" category for most people.
What's the alternative? There was a flaw in the aircraft design, a dreadful one. Some fundamental structural issues and conflicts of interest at the FCC (that the NTSB has been complaining about for roughly its entire existence) were again highlighted. Boeing executives turned out to be as subject to lying to themselves when making difficult decisions as the rest of humanity. Other nation's certification processes turned out be inappropriately trustful of the American certification process (that's widespread through all sorts of areas, but one of the few positives of the Trump regime will be a re-evaluation of that little habit).
People make mistakes. Systems (human and technological) fail. The holes in the Swiss cheese sometimes line up just enough to permit a tragedy, as issues with training and maintenance lined up with an inexcusable design flaw to allow one crash and then bureaucratic inertia and incompetence (and perhaps even a little racism) allowed a second. The reason modern commercial air travel is so absurdly, unimaginably safe is that we always, always make sure we understand these events when they lead to tragedy or even just near misses.
This has happened before. If you think aircraft automation vs. pilot is a new problem, take a look at Airbus' history. The pre-MAX 737 (arguably the safest commercial aircraft in widespread use) shipped with a flaw in its rudder actuator design that took four crashes and a half-dozen near misses to finally figure out. I'd happily board one (MAX or otherwise) tomorrow, knowing that among the myriad of things that might kill me, rudder actuator failure or MCAS won't be found. Because we fix these things when we figure them out. And not just the part. The process that allowed the part to fail so tragically as well.
Remember the DC-10? Even a cursory read of its history puts the MCAS affair to shame, and it ultimately killed not only hundreds of passengers but the reputation and brand of the legendary Douglas Aircraft. Know what else? Still flying. Pilots love them, although they call them MD-10s now and they're rarely used for passenger service. There's a good chance your next package from Amazon will fly on one to get to you. And when the pilots board one they can be pretty certain that even if the plane kills them, it won't be with a cargo bay door failure. Because we fixed that.
What do people propose? Shut down Boeing? Let Airbus have a monopoly on commercial air vehicles? That's won't serve safety. Start buying our aircraft from Tupolev? Might want to check their record first.
Want carriers to just scrap their 737 MAX tails? Right now? That's the same thing as just declaring bankruptcy. The investment in a commercial aircraft takes years of steady use to pay off, and no one in the industry is in a financial position to take that hit. Once the aircraft are deemed safe (and, trust me, the MCAS problem will be solved), they should be flown. If you really want to save a lot of lives, lobby to hold the automobile or pharmaceutical industries to even a fraction of the standards we require of commercial air travel carriers.
It lists no fewer than 89 findings about the causes that lead to that crash and 25 recommendations for how to make sure it doesn't happen again. The industry culture that makes such reports possible, makes them public, and takes them very seriously is why I would feel safe flying on a 737 MAX tomorrow. Because I have very good, very well supported, evidence that it would be safe to do so.
We don't yet have a final report on the Ethiopian Airlines mishap, and the investigation process has been a little more political that what we saw with Indonesia, but the preliminary reports and analyses point to a similar complexity of causes, and will undoubtedly generate a similarly thorough and useful set of recommendations.
Let me remind you of why we're all still talking about Boeing.
Not once, but TWICE, software taking readings from faulty sensors caused the airplane to nosedive into the ground, killing every single person on board, with the pilots powerless to take over.
It happened once, Boeing and the U.S. government reassured everyone that it wasn't going to happen again, then it happened again.
When nations around the world began to issue emergency orders to ground the 737 MAX, the U.S. was the last to do so.
The leaked emails from Boeing indicate clearly that this was not a freak accident, but a product of a corporate culture of irresponsibility and recklessness at Boeing reaching mind-boggling proportions. [0] Here are some quotes from said emails:
"This airplane is designed by clowns who in turn are supervised by monkeys."
"We'll probably have to go to other regulators around the world to Jedi-mind trick them into accepting the FSB findings, but that shouldn't be too hard."
"Would you put your family on a Max simulator trained aircraft? I wouldn't."
"I still haven't been forgiven by God for the covering up I did last year."
> What do people propose? Shut down Boeing?
No. What I propose is what I'm doing; I don't fly on Boeing planes anymore. If I see a flight change to a Boeing plane, I call the airline and demand to be switched to a different flight. It worked once, and I plan to keep doing it.
> Want carriers to just scrap their 737 MAX tails? Right now? That's the same thing as just declaring bankruptcy. The investment in a commercial aircraft takes years of steady use to pay off, and no one in the industry is in a financial position to take that hit.
I don't care what carriers have to do. At this point, I would consider it justice to see Boeing go bankrupt. And I really don't care if every airline that runs Boeing planes goes bankrupt. Companies come and go. Money is made and lost. But human lives cannot be returned and corruption like this can't be allowed to continue.
But that won't happen. What will happen is that the government will continue to bail out all the above, indefinitely. But if enough customers begin showing concern over Boeing, the airlines will purchase their planes less and less, and we can expect things to get better, either with Boeing's demise or its reform.
>Not once, but TWICE, software taking readings from faulty sensors caused the airplane to nosedive into the ground, killing every single person on board, with the pilots powerless to take over.
I believe technically if they followed the runaway trim in memory checklist the system would have been disabled? This is how the pilot of the Lion Air flight the day before prevented disaster.
>At this point, I would consider it justice to see Boeing go bankrupt.
And what when this happens to Airbus, is that the end of air travel? As long as humans are involved, there will be issues. Airbus still averages pilot input, rather than providing feedback to each pilot, which has led to more than one accident (AF447 being one example, where one pilot tried to pull up out of a stall warning).
>I believe technically if they followed the runaway trim in memory checklist the system would have been disabled? This is how the pilot of the Lion Air flight the day before prevented disaster.
Yes, but the failure they experienced feels absolutely nothing like runaway trim. It's great that some pilots were able to troubleshoot the failure in time, but that's not something you can really expect from everyone. Adequate training may well have prevented the mishaps, but the airplane as a system was still poorly designed.
I agree and they should fix the process as well as the causes (as they have).
But there was a way to stop it is all I'm saying (the claim was that there wasn't). The Ethiopian Air pilots also tried, but missed a crucial step when running the checklist.
If your interest is understanding what happened and how it could have been prevented, you would do far better to read the accident reports, in their entirety, carefully. A half dozen cherry-picked and context-free lines from a store of thousands of emails and other documentation are useful for getting clicks and stoking reader emotions to drive social media reposts but are typically less dispositive in failure analysis.
If I went trolling through all the emails about any multi-billion project, you don't think I could pull out a few to support whatever narrative I wanted to push? Especially if it was a nice juicy one that I could count on much of my audience to really want to be true?
Do you honestly think that there was anyone at Boeing that thought, "well, this aircraft is definitely unsafe and is going to kill a bunch of people, which will likely destroy this company and greatly damage the entire industry I've spent my whole career on, and that I and everyone I care for will regularly board and fly in, but hell, my stock options are due, so what the fuck, I think I'll organize a conspiracy to commit mass murder"? These were human and systemic failures that, like most human failures, were perhaps not innocent but understandable. Of course, there were warnings. There always are. The problem is that the real warnings are easy to pick out of the noise after the fact. Before the fact, they're mixed in with an awful lot of other concerns and warnings and complaints that will turn out to have been about nothing.
The main difference with this particular incident of corporate malfeasance and systemic failure is that the we have a process that will identify and publish what happened, why it happened, and what can be done to correct it. Now, that certainly doesn't generate a nice simple narrative with cartoonish villains that even the most vapid readers will cherish, but it does generate an incredibly safe commercial aircraft industry.
Lashing out at Boeing and its customers isn't cost free. Removing Airbus' competition won't make its aircraft safer. Destroying the major commercial carriers won't encourage small carriers to expand into the new hulls and training and maintenance standards that safe travel requires. Making air travel more expensive and balkanizing the industry into a maze of low-cost carriers will make it less safe, less tenable, and do enough damage to the world economy that inequality and unavailability will cost far more lives and livelihoods than even the most gratuitously simplistic narrative about Boeing could begin to compass.
> Do you honestly think that there was anyone at Boeing that thought, "well, this aircraft is definitely unsafe and is going to kill a bunch of people, which will likely destroy this company and greatly damage the entire industry I've spent my whole career on, and that I and everyone I care for will regularly board and fly in, but hell, my stock options are due, so what the fuck, I think I'll organize a conspiracy to commit mass murder"? These were human and systemic failures that, like most human failures, were perhaps not innocent but understandable. Of course, there were warnings. There always are. The problem is that the real warnings are easy to pick out of the noise after the fact.
No, that would indicate thoughtfulness & deliberation. Everything that seems to have emerged indicates recklessness and a lack of commitment (at the company level) to sound engineering processes, bordering willful disregard.
You absolutely have the right to not board an aircraft if you don't feel safe, and should exercise it. Laurence Gonzales has a story about declining to fly on a DC-10, which saved his life. But even he admits that that decision wasn't rational: you can't judge a decision by what you know after the fact. Even at its worst, a flight on a DC-10 was much safer than his morning commute.
You'll have less luck getting a refund for that decision, but I do appreciate your admitting that the decision is about your feelings, not demonstrable evidence.
the 737 max is probably the safest plane in the world right now. like jack in the box was actually the safest place in the world to eat right after they were serving the ecoli burger
Would you have said that before and after the first Lion Air 737 Max crash prior to the Ethopian crash?
Certainly a lot of people have spent a lot of time looking into a lot of the plane's systems. But are there more fundamental issues that can't or haven't been addressed?
Those same people spent a lot of time prior to certification looking into the plane...
I don’t know much about airplane design. But if you told me that a software was so buggy that it was pulled out of market and then years were spent fixing the bugs in it, I almost certainly would not trust the resultant software more than I would have trusted a complete rewrite.
If aircraft manufacturing is anything like software development (and considering a lot of the issues in the Max are software related there’s at least some of that), this does not make me confident in the Max at all.
Is your software safe from multiple simultaneous cosmic bit flips? The FAA required Boeing engineers to handle this situation when rewriting parts of the software even though flight computers are hardened against this sort of anomaly.
There's a similar tenet for purchasing refurbished hardware. The supplier only wants to stomach a single RMA, so they will put in the effort to make sure the re-certified doesn't ever come back.
That's not true at all. All work is a trade-off between effort/cost and reward. The person refurbishing the equipment will decide how much work is reasonable for the amount of money they are making on it.
In an ideal world, we want to sell something that works perfectly and don't want any returns for sure but the truth is we never know its perfect and perfection costs money.
A piece of hardware that has been re-certified has absolutely been through more extensive testing than those sold as new, its a simple fact of the matter
>It’s not clear that’s true. Flying doesn’t appear to be causing covid to spread.
Come on now. Just because we don't have peer reviewed scientific studies confirming the fact doesn't mean common sense can't apply. You're sitting in an enclosed terminal with thousands of other people from all over the world who may or may not even be masked, waiting in multiple lines with no social distancing, and touching an endless amount of common surfaces. It's spreading like wildfire at airports without even including the actual flight itself.
I understand why common sense wants you to make that last statement, but we would be hearing that in the news. So far, I haven't run across stories asserting spread in airports.
How did covid get to Europe or the Americas? I realize you were trying to talk only about person-to-person contact while on the plane, but don't forget why covid spread so quickly to all the other countries on earth in the first place, that's part of what parent was referring to.
Yeah, people can have it, travel, and spread it elsewhere, certainly. I mean that person to person contact. If you're being safe at each end, flying doesn't appear to be causing an impact.
They could have got it just as easy at the store before or after the flight, in the airport, or in the uber. Hard to know... Certainly possible but having flown a few times this past year, not too worried.
>The airline is trying to entice passengers to take a tour of the plane at selected airports.
This is just so sad. One, because American clearly thinks customers are stupid enough to think that this will assuage their fears, and also because the American public is stupid enough that this will probably work for some people
> Through 2015, the Airbus A320 family has experienced 0.12 fatal hull-loss accidents for every million takeoffs, and 0.26 total hull-loss accidents for every million takeoffs; one of the lowest fatality rates of any airliner.[3]
If you looked at the crash rates of the A320 after two years of commercial service, it wouldn't have been so great either, with AF296 and IC605 having both occurred. (Though, to be fair, both were pilot error… but both 737 MAX crashes were initially reported as such too.)
I’d take an A320 over a 737 every day, the latter seems so cramped and a little older, to be honest. Or maybe me only experiencing them on Ryanair made me think that way.
And also country of origin. If you look at that list, there are WAY more accidents in non-US and non-EU countries. The same is true of commercial air accidents in recent history:
I do not trust modern day American corporations nor the oversight bodies. There are too many financial incentives to cut corners.