This is off-topic, but WalterBright's participation here has reminded me of my own weaknesses. Everything I have read about the 737Max has put a pitchfork in my hands to go after Boeing. Walter's are the first comments I have read that make me think perhaps Boeing wasn't completely, utterly, criminally unjustified.
It is interesting that Walter has chosen to jump in like this, and to hold his position so firmly so publicly. He must realize that this action threatens to paint him very unfavorably to a lot of people. There seems to be no reason for him to speak out and take such a risk.
To do this seems to me to require either a certain level of stupidity or a certain level of conviction and courage. My impression is that Walter has considerable courage and some motivation to try to counteract public ignorance.
FWIW, Walter's courage has given at least one person pause. I'm going to put the pitchfork down for a little bit. Boeing still isn't on my good list, but now I admit that I don't know as much about this as I thought I did.
The outrage mob over this has made it difficult for the whole truth to surface. For months, many people have said exactly what Walter is saying in this thread, Walter just happens to be more eloquent and qualified than other people who have made generally the same points.
Most of these people receive insults and downvotes so they stop talking about it. This leads to the classic “spiral of outrage” and the truth becomes lost.
I’m tooting my own horn here, but I’ve said what Walter has said in previous threads, and my comments were often downvoted into invisibility and I eventually gave up trying to point out that the pilots, the airlines, and the maintenance staff of the 737-MAX deserve some portion of the blame in addition to Boeing. Planes have become so safe that some airlines skip out on pilot emergency safety training, and Airworthiness Directives were ignored by the two airlines which had a 737-MAX crash.
This doesn’t mean that Boeing has no culpability, but it does mean that Boeing is not the sole party at fault. For everyone saying “Boeing cut costs and cost lives”, this is equally true for the airlines which skimped on pilot training and skimped on maintenance. The 737-MAX crashes were the result of a series of bad decisions and mistakes, not merely the result of bad MCAS system design.
Note: my late father worked at Boeing for 25 years so I have some personal reasons for wanting to defend Boeing. My mother’s widow pension is also dependent on Boeing stock not cratering into the ground.
>The paradox is that the failures of the 737 Max were really the product of an incredible success: a decades-long transformation of the whole business of flying, in which airplanes became so automated and accidents so rare that a cheap air-travel boom was able to take root around the world. Along the way, though, this system never managed to fully account for the unexpected: for the moment when technology fails and humans — a growing population of more than 300,000 airline pilots of variable and largely unpredictable skills — are required to intervene. In the drama of the 737 Max, it was the decisions made by four of those pilots, more than the failure of a single obscure component, that led to 346 deaths and the worldwide grounding of the entire fleet.
In a way, these accidents were inevitable. When safety is so assured, some airlines will begin to take a casual approach to training their pilots. Post-accident, this leads to Boeing/Airbus making their planes even more immune to poor airmanship, and the virtuous cycle continues until another accident inevitably happens, and Boeing/Airbus get fingered instead of the airline (because we want to blame the agents we think we can change, rather than the agents we cannot change).
Can you be a little more specific about what WalterBright said that changed your mind? Because the only thing I see that could possibly be considered a mitigating factor is this:
> Both the LA and EA did make the adjustments within 10 seconds. They then did NOT throw the cutoff switches
(Emphasis added, because I missed this the first time I read it.)
If I squint hard enough I guess I can see a tiny hint of merit in the argument that the fault for the two crashes lies at least in part with the pilots because they failed to throw the cutoff switches. But that seems like a mighty thin reed to me. Have I missed something?
I don't think you have. Bright's arguments have focused entirely on the design of the MCAS software, and have as far as I can tell completely ignored the fact that that software, driven by input from a single AoA sensor, creates a very short critical failure path which requires immediate and precise human intervention to avert a fatal accident. That such human intervention was imperfectly performed in two cases does not indict the humans in question, so much as it indicts a design which errs so far on the side of unsafety that perfection in human behavior is required to prevent it killing everyone on board a commercial aircraft.
Any competent engineer knows that a design which requires human perfection for safety is a design not only doomed to failure, but a failed design in itself. At least one Boeing engineer raised this very concern during the 737 MAX design process, only to be quashed by management. It would be invidious to suggest that at least one ex-Boeing engineer should argue in the defense of that design out of any motivation other than a genuine conviction of the merit in his argument. But conviction alone doesn't suffice to render that argument meritorious, and I'm surprised and disappointed to see anyone here or elsewhere claim otherwise.
Thanks, but I really would like to hear what supportlocal4h has to say about it. You're just repeating the party line. (And just for the record, I agree with the party line. But I think it's important to listen to and understand dissenting views.)
1. Boeing is not blameless.
2. Boeing has a point about MCAS issues manifesting exactly like another well-known event in other models and having the exact same solution.
3. The well-known solution to the well-known event is one that pilots must memorize because they don't have time to look it up.
4. The pilots seem to have demonstrated that they recognized the problem and, in fact, executed the well-known solution in time. They just failed to complete all the steps for some unknown reason.
5. Points 2-4 don't mean that Boeing is perfect. MCAS needs to be fixed. But it isn't completely absurd to argue that MCAS really is so similar in its misbehavior and so identical in the correct response that a reasonable person might expect pilots to do the right thing even if they had never heard of MCAS.
Taken together, this paints a picture to me that is different than the completely evil, conniving picture I had. I'm not sure where to draw the line between them, but probably not on the extreme end where I had it.
But my point is not so much about Boeing. I was observing the actions of a person who took what I expect to be a very unpopular stand in the face of overwhelming popular opinion. For what? Who cares if somebody else is mischaracterized? There's nothing you can do about it except get yourself muddy. Just let it happen and keep your head down.
I don't know why Walter is speaking up now. I'm not sure how much it changes my opinion. But I still tip my hat to a person who will say what they think is right even when they know they will be burned at the stake for it.
> Boeing has a point about MCAS issues manifesting exactly like another well-known event in other models and having the exact same solution.
No, they don't, because (a) the MCAS issue does not manifest exactly the same as another well-known event (runaway trim), and (b) the solution to the MCAS issue is not the same as the solution to runaway trim.
Re (a), normal runaway trim on a 737 manifests as a continuous automatic adjustment of trim. The trim starts moving and doesn't stop until the pilot disables the automatic trim system entirely.
The MCAS issue, however, manifests as an intermittent automatic adjustment of trim, at times that seem completely random to the pilot. It is not at all the same as normal runaway trim.
Re (b), the procedure for normal runaway trim on previous 737s is to shut off the automatic trim system. You can then use the manual electric trim system to put the trim back where it belongs. The critical fact here is that shutting off the automatic trim system does not shut off the manual electric trim system.
But on the 737 MAX, shutting off the automatic trim system, which is what you need to do to disable MCAS, also shuts off the manual electric trim system. So now the only way to get the trim back where it is supposed to be is to use the mechanical trim wheel; and MCAS has enough control authority to put the trim in a place where it is impossible for the pilot to exert enough mechanical force on the trim wheel to move the trim back to where it belongs. So the normal runaway trim response procedure does not work for an MCAS failure.
There is a way to recover from an MCAS failure, which is to wait until you are in between intermittent MCAS adjustments of the trim, use the manual electric trim system to put the trim where it is supposed to be, and then shut off the automatic trim system (which, as noted, also disables the manual electric trim system in the 737 MAX). Then you have MCAS disabled and you have the trim in a place where you can use the mechanical trim wheel if needed. But that procedure is not the standard procedure that 737 pilots are trained to do.
> MCAS issues manifesting exactly like another well-known event in other models and having the exact same solution
By "another well-known event" do you mean a runaway trim? Because if you do, then you're mistaken. MCAS and runaway trim differ in significant ways. And if you don't, what do you mean?
> I don't know why Walter is speaking up now.
Have you considered the possibility that he's a shill?
> Have you considered the possibility that he's a shill?
A fair question. I left Boeing's employ (as a flight controls engineer) in 1982. I am not a spokesman for Boeing, paid or otherwise. The facts I've presented here are all public information (though routinely omitted from sensationalist articles about it). My interpretation of those facts is mine alone.
We'll see what the final NTSB report says. They have earned a reputation for going where ever the facts lead them, regardless of political pressure. I sincerely hope they continue with this tradition, as it is the only way to make airline travel safe.
This highly political case will surely test the NTSB's commitment to dispassionate examination of the facts. We shall see.
> I am not a spokesman for Boeing, paid or otherwise.
Isn't that exactly what an effective shill would say? It could even be true. "Shill" and "spokesman" are not synonyms.
FWIW, I went back and re-read some of your comments in other branches of this thread and it's really hard for me to figure out what your position actually is. For example:
> It's true that if the MCAS software requirements weren't inadequate, the accidents would not have happened.
Apart from being a nearly-impossible-to-parse triple negative, it's just absurd on its face. No requirements can ever prevent an accident. I can write down as a requirement: "MCAS software must never cause the plane to crash." But obviously the planes did not crash because someone failed to write down that requirement.
If you're really a flight controls engineer then you obviously meant something else. But have no idea what that something else could possibly be.
> But I don't see why the shortcomings in the MCAS software design requirements were the result of cost savings.
Again, it is hard for me to wring any plausible interpretation out of this sentence under the assumption that you are well informed. It is well known that the reason MCAS exists at all is because Boeing attempted to make a radical change to an existing airframe design without getting it re-certitifed, and the reason for doing that was cost savings, both for Boeing and its customers. What other underlying reason could there possibly be for MCAS to exist at all?
> I did not defend Boeing's MCAS design.
OK, but do you see how someone could come away with that impression?
> Isn't that exactly what an effective shill would say?
Of course. There's no telling how deep this conspiracy to point out publicly available facts goes :-)
> No requirements can ever prevent an accident.
That's not what I meant by requirements. Boeing came up with a set of rules for what the software must do in each situation. This is called the requirements specification for the software.
Anybody who contracts with someone to write some software comes up with such a specification.
> What other underlying reason could there possibly be for MCAS to exist at all?
There's nothing at all wrong with the concept of MCAS. There's a long history of flight control augmentation in jet airliners to make them behave better. In fact, you cannot control a jetliner at all without augmentation, it's too fast and heavy. It's the implementation that was faulty.
The B-17 was perhaps the largest successful airplane with no augmentation, and a strong man could barely handle it (source - my dad was a B-17 pilot).
The 757, which I worked on, has fully powered controls. The control column just opens and closes valves. In order to prevent the pilot from inadvertently making violent maneuvers a hydraulic "feel computer" was added to push back on the stick to fake the behavior of a manually controlled system. The forces it imparted had to be dialed back to accommodate the advent of female pilots, which caused some worry that the men would overcontrol the airplane. Fortunately, that turned out to not be a problem.
> OK, but do you see how someone could come away with that impression?
I not only never defended MCAS' design, I wrote that it was faulty several times. You should ask the someone why they conclude the opposite.
Everybody is at fault. Pilots for not flipping the switch. Foreign aviation regulations for not requiring more knowledge (hours) in the cockpit. Airlines for not buying safety equipment. Boeing for not making safety equipment standard and then playing the cover-up/shift-blame game.
You all can debate who is responsible for what %, but I’m not a judge nor a jury so I won’t speculate. But facts is facts, and everyone in the chain above deserves blame
> have as far as I can tell completely ignored the fact that that software, driven by input from a single AoA sensor, creates a very short critical failure path which requires immediate and precise human intervention to avert a fatal accident.
Not too precise. Lowering flaps or not raising them in the first place solves it since flaps disengage MCAS. And on the Lion Air flight, the AOA sensor was already squawked prior to the flight but the incompetent Lion Air maintenance process ignored it despite that sensor being on the MEL for that airplane. Lion Air allowed a legally un-airworthy aircraft to depart. Boeing owns some of the blame, but the pilot-factories of third world airlines deserve a lot of the blame as well. In Lion Air’s case, their maintenance failures deserve 100% of the blame because they allowed a plane to take off with a system required for airworthiness to not be fixed.
If a plane requires a widget to be legally airworthy and maintenance and the pilot in command knowingly allowed the plane in the air without that functioning widget, anything that happens as a result afterwards is the fault of the maintenance and pilot in command. That the widget was required; that’s on Boeing. That the widget failed, that’s also on Boeing; that the plane was allowed to fly by that airline — that’s on the airline.
> Lowering flaps or not raising them in the first place solves it since flaps disengage MCAS.
But the pilots weren't told that and didn't know it. Nobody was trained or informed that "lower flaps" was a proper response to "trim system malfunction", and I don't see why it would be an obvious thing to come up with on your own.
> they allowed a plane to take off with a system required for airworthiness to not be fixed
Did Lion Air know the AoA sensor was required for airworthiness? Nobody outside Boeing knew MCAS existed at the time.
They did use the cutoff switches with the nose down too far. The correct procedure (as stated in the Airworthiness Directive distributed to all MAX crews) is to use the column trim switches to restore normal trim, then use the cutoff switches.
They had already used the column trim switches twice to restore normal trim.
...but then turned them back on afterwards because they weren’t sure if that was the correct action. MCAS reenabled until aerodynamic failure caused the crash (wind speed prevented elevator from rising).
Ultimately, more knowledge in the cockpit would have helped, see previous LA flight where pilot with training knew the correct action to take.
> Walter's are the first comments I have read that make me think perhaps Boeing wasn't completely, utterly, criminally unjustified.
They shouldn't make you think that; the fact that, considered in the abstract, there were actions the pilots could have taken that would have avoided the fatal crashes does not change the fact that Boeing designed a system where the failure of a single sensor could cause a fatal accident. There can be responsibility in both places.
It is interesting that Walter has chosen to jump in like this, and to hold his position so firmly so publicly. He must realize that this action threatens to paint him very unfavorably to a lot of people. There seems to be no reason for him to speak out and take such a risk.
To do this seems to me to require either a certain level of stupidity or a certain level of conviction and courage. My impression is that Walter has considerable courage and some motivation to try to counteract public ignorance.
FWIW, Walter's courage has given at least one person pause. I'm going to put the pitchfork down for a little bit. Boeing still isn't on my good list, but now I admit that I don't know as much about this as I thought I did.