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Boeing's Crashes Expose Systemic Failings

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Re: Boeing's Crashes Expose Systemic Failings

#11

Post by barkingcat »

PhasmaFelis wrote: post #2

> By the end, the planes had gained so much speed and were descending so steeply that the pilots would have had to possess superhuman strength to counter the pressure on the horizontal stabilizer trim. I thought these systems were all fly-by-wire now? Edit: Don't downvote for asking an honest question, guys. Thanks to the people who actually answered.

The plane in question is the 737 Max, which is the renewed version of the 737 series that started production in 1968. The whole family of planes does not have fly-by-wire.

Re: Boeing's Crashes Expose Systemic Failings

#12

Post by nness »

FabHK wrote: post #9

> What's more, over the course of his 55 years in the profession, he [lawyer Marc Moller] [has] learned that every plane crash can be traced back to a single, simple cause. I don't know, that strikes me as nonsense. It's precisely the interplay of many factors that lead to an accident - and if any one of them had been different, the outcome might have been different. See Reason's "swiss cheese" model of accidents - a…

I think, as a lawyer, he's using the phase a "simple cause" to mean "a singular responsibility, culpability, and liability."

Re: Boeing's Crashes Expose Systemic Failings

#13

Post by FabHK »

linuxftw wrote: post #7

It's obvious to me neither the FAA nor Boeing attempted to accurately replicate the first crash scenario, because this could have wholly averted the second crash. As soon as the planes were grounded, we were getting all sorts of reports about the stablizer being too hard to move and basically an unrecover situation. Jail time is the only outcome I will accept.

How is it obvious to you that they didn't investigate the first crash sufficiently?

I'd say some time after the first accident it was reasonably well understood what had happened, and the FAA (and many others!) concluded that it was still safe to fly the plane, as the pilots could easily interrupt the accident chain by doing the right thing quick (as the pilots on the Lion Air flight preceding the accident flight had done).

Why that assessment was wrong is a complicated story that has to be examined carefully.

From what I gather, in aviation safety circles "jail time" is very rarely considered a wise answer. As soon as you threaten jail, people will cover their ass and obstruct investigations. Instead, the goal is and should be to examine the entire system to ensure accidents don't repeat, and by and large, the system works exceedingly well.

Re: Boeing's Crashes Expose Systemic Failings

#14

Post by FabHK »

nness wrote: post #12
FabHK wrote: post #9

> What's more, over the course of his 55 years in the profession, he [lawyer Marc Moller] [has] learned that every plane crash can be traced back to a single, simple cause. I don't know, that strikes me as nonsense. It's precisely the interplay of many factors that lead to an accident - and if any one of them had been different, the outcome might have been different. See Reason's "swiss cheese" model of accidents - a…

I think, as a lawyer, he's using the phase a "simple cause" to mean "a singular responsibility, culpability, and liability."

Probably. Goes to show that the lawyer representing the victims and the safety folks (NTSB etc.) trying to make sure an accident does not repeat have very different goals, incentives, ways of thinking, etc.

Re: Boeing's Crashes Expose Systemic Failings

#15

Post by FabHK »

msbarnett wrote: post #8
PhasmaFelis wrote: post #2

> By the end, the planes had gained so much speed and were descending so steeply that the pilots would have had to possess superhuman strength to counter the pressure on the horizontal stabilizer trim. I thought these systems were all fly-by-wire now? Edit: Don't downvote for asking an honest question, guys. Thanks to the people who actually answered.

The 737 series, including the MAX, has mechanical linkages to the control surfaces. Boeing’s recommendation for dealing with a runaway MCAS scenario, in fact, was to cut power to the stabilizer trim motors at just the right moment in a short window of opportunity between cycles of it running, and then have the pilot manually crank the trim by hand turning a wheel that pulls a cable. With excessive speed, or too much…

Yes. Truly terrible. And, possibly the pilots could turn the wheel if both collaborated on it - but then, who pulls back the control column to keep the elevator up? Terrible terrible situation.

Re: Boeing's Crashes Expose Systemic Failings

#16

Post by dsfyu404ed »

nness wrote: post #6

> Bickeböller's complaint endangered the planned inauguration of the 787, which had already been delayed due to technical difficulties. The problems identified by the engineer, however, weren't addressed by Boeing, which is why he turned to EASA in June. [...] In those papers, it states that management and top executives at Boeing had ordered that the coordination problems with the company's suppliers be "closed." Th…

We're talking about the 787 here, not the 737 variant that's falling out of the sky. Despite initial teething issues (something all big systems like this have to some extent) the 787 has gone on to be a successful design. To say "I, for one, hope this plane never flies again" is an overreaction, especially since said problems have been fixed and the plane is in service without the issue popping up.

Re: Boeing's Crashes Expose Systemic Failings

#17

Post by xvector »

lisper wrote: post #5
yeezul wrote: post #3

Earlier quoted context omitted.

My understanding is that the 737 does not use Fly by wire [1] and if I remember correctly it's because they wanted to piggyback on the original 737 certification. I could be wrong. 1: https://www.quora.com/Does-the-737-MAX-family-use-fly-by-wir...

> I could be wrong. You're not :-) The 737 still has direct mechanical linkages to the control surfaces. Changing that would require completely redesigning the aircraft.

What's the motivation for this? Regulatory, I get that. But why use direct mechanical linkage in an era where fly-by-wire would probably be faster/safer/etc?

Re: Boeing's Crashes Expose Systemic Failings

#18

Post by mieseratte »

FabHK wrote: post #14
nness wrote: post #12

Earlier quoted context omitted.

I think, as a lawyer, he's using the phase a "simple cause" to mean "a singular responsibility, culpability, and liability."

Probably. Goes to show that the lawyer representing the victims and the safety folks (NTSB etc.) trying to make sure an accident does not repeat have very different goals, incentives, ways of thinking, etc.

Given how vague the language is, I don't know that we can necessarily draw a conclusion.

That "single item" might be the component-failure, that which fell through the aligned holes in the swiss-cheese, or it could be "the single layer of the system that was left out" that would have mitigated or otherwise precluding the class of failure.

One could castigate Boeing for not having a more redundant use of sensors the MAX case, or one could say "Why don't you have 'hackers' as a part of your process, whose job it is to find these classes of problems and raise all hell when they do."

Then again based on the phrasing "single, simple cause" I'm more inclined to say you're on the money. That the lawyer is looking at the component-failure rather than "avoiding non-redundant systems" as a class of problem to solve.

Re: Boeing's Crashes Expose Systemic Failings

#19

Post by notfashion »

FabHK wrote: post #9

> What's more, over the course of his 55 years in the profession, he [lawyer Marc Moller] [has] learned that every plane crash can be traced back to a single, simple cause. I don't know, that strikes me as nonsense. It's precisely the interplay of many factors that lead to an accident - and if any one of them had been different, the outcome might have been different. See Reason's "swiss cheese" model of accidents - a…

The journalist writing the article may have distorted what he said. Is their a dogma of accident investigation that says there is always a root cause, or is it just a conventional way of working? There are certainly domains in which root cause analysis is inappropriate—psychiatry, for example.

https://en.wikipedia.org/wiki/Root_cause_analysis

Re: Boeing's Crashes Expose Systemic Failings

#20

Post by LifeLiverTransp »

FabHK wrote: post #13
linuxftw wrote: post #7

It's obvious to me neither the FAA nor Boeing attempted to accurately replicate the first crash scenario, because this could have wholly averted the second crash. As soon as the planes were grounded, we were getting all sorts of reports about the stablizer being too hard to move and basically an unrecover situation. Jail time is the only outcome I will accept.

How is it obvious to you that they didn't investigate the first crash sufficiently? I'd say some time after the first accident it was reasonably well understood what had happened, and the FAA (and many others!) concluded that it was still safe to fly the plane, as the pilots could easily interrupt the accident chain by doing the right thing quick (as the pilots on the Lion Air flight preceding the accident flight had…

So, asses are currently uncovered?
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