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FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

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Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#231

Post by linuxftw »

tanakachen wrote: post #109
rfugger wrote: post #59

I'd be pretty comfortable flying it after all this attention and review. It will probably be the best reviewed passenger plane software developed in America, if not the world once this is over. Boeing deserves a 9-figure fine though, and its shareholders should lose massively to make sure this doesn't happen again.

> It will probably be the best reviewed passenger plane software developed in America, if not the world once this is over. The problem is that this is not actually a software problem. It’s an airplane design problem, and Boeing is trying to convince you that it’s just the software. Even if the software is perfect, this plane remains a flying coffin until it is redesigned from scratch. The only real fix is not to fly…

Yes, everyone focuses on the software here. They assume that MCAS just needs a few updates and it will be all good.

How can we trust that assessment? What if the plane is inherently unsafe? There's been no critical 3rd party review of the plane without MCAS in operation. Everything is a Boeing talking point. Their proposed fix is 2 AoA sensors (on top of whatever slapped-together software updates), and if they disagree, disable MCAS. That's going to decrease the MTBF of that system. So, IMO, the real question is, why should MCAS even be allowed if it's so easily disabled? Either the planes can fly without it or they can't.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#232

Post by cmiles74 »

brentm wrote: post #55
jussij wrote: post #41

The FAA suffered a major loss of credibility in their handling of the first round of testing/accreditation of the MAX. The FAA can't afford another stuff up this second time around and as such I suspect they will be checking every aspect of the plane in very fine detail. That could spell more trouble for Boeing.

I think overall we should consider this process a very positive thing, FAA and Boeing (and Airbus as well) are all going to learn a lot from this process which will make air travel safer in the future. It's unfortunate that it took two tragedies to get us here but if you look at the history of aviation improvements this isn't the first and it won't be the last time.

I would prefer that Boeing be put out of business, rather than "learning a lot from this process". I think that the word "unfortunate" is too conservative to cover this situation.

A corporation is not a person and punishment isn't always the answer, but we are looking at a lot of deaths and this new issue sounds like it could have caused even more. If the FAA had missed this one we could have been looking at another crash. Maybe putting Boeing out of business would serve as a cautionary tale to the remaining companies in this space that they should be making more conservative choices when it comes to development of a product that has the potential to injure or kill such a large number of people.

As it is, I'm not sure what the moral of this story is for Boeing. Is it that the company is "too big to fail"? It is that they need to tough out the bad press to really be successful?

I worry that maybe it's something along the lines of "you have to crack a few eggs to make an omelette."

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#233

Post by jussij »

jonknee wrote: post #138
jussij wrote: post #84

Earlier quoted context omitted.

Hence the reason I said time will tell. But there are also many examples of aircraft with terrible early safety records that never recovered from their bad start.

> But there are also many examples of aircraft with terrible early safety records that never recovered from their bad start. From Boeing? They have a history of sorting their shit out. Maybe this time is different, but I doubt it.

I would say times have changed at Boeing, because it seems for the MAX, rather than sorting their shit out they instead seem to prefer covering up their design faults.

They also seem to have a bad habit of blaming the dead pilots for not being able to fly they broken planes.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#234

Post by hwestiii »

This all points up the glaring conflicts of interest in the corporate business environment. Most of us think that Boeing is the business of building airplanes, but as a publicly traded company, its real business is making money for its shareholders, and aerospace is just a vehicle toward that end. The Boeing CEO's steadfast refusal to take responsibility for these two crashes are nothing more than CYA designed to limit or defer financial responsibility for >300 deaths and protect and privilege shareholder value above the safety and well-being of the flying public.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#235

Post by BuildTheRobots »

ls612 wrote: post #25
closetohome wrote: post #20

Earlier quoted context omitted.

Or conversely what are the odds that the others have similar undiscovered or undisclosed issues?

Fairly low, given that every other type in widespread service has been flying much longer than the MAX with a very good safety record

And Boeing do have form when it comes to software.

https://www.engadget.com/2015/05/01/boeing-787-dreamliner-so...

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#236

Post by faraggi »

kahirsch wrote: post #86

When the Boeing CEO had his press conference in April, he said "we've confirmed that the MCAS system as originally designed did meet our design and safety analysis criteria and our certification criteria."[1] I yelled at the screen "you know that means the criteria are flawed , right? If the procedures didn't catch this mistake, that means there are other mistakes that weren't caught!" A flabbergasted reporter then a…

The question asked in 14:05 was super clear, and he repeated like a parrot the same thing he had said earlier during the press conference.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#237

Post by salawat »

cmurf wrote: post #122
teh_infallible wrote: post #97

I hate the fact that all discussion focuses on the software and ignores the airframe.

What's the problem with the airframe? What's the problem with the larger engine nacelle causing a different pitching moment? I've yet to read either of those violate any portion of FAR 25. There is still an open question whether the MAX should have or will have a separate type certificate from other 737's, thereby requiring pilots of a type rating to fly the MAX, thereby requiring full disclosure and training on all…

The problem with the airframe is that the shape of the nacelles, and their forward position create extra lifting surface in front of the center of gravity at high AoA.

What this results in, is a non-compliant stick force response curve at high AoA. This violates FAA regulations which state that the stick force required to bring a plane to a stall must consistently increase all the way to the stall. No sickening or decreases in apparent required stick force are certifiable as airworthy for Civil Transport Aircraft.

This was explained in a recent Seattle Times Article. I also posted it here as a theory back in March abouts.

[1]https://www.seattletimes.com/seattle-news/times-watchdog/the...

[2]https://news.ycombinator.com/item?id=19568158

[3]relevant FAR 25.173, see stick force requirements

MCAS was designed to artificially induce a mistrim which has the end result of smoothing out that force curve. Initially it was only for high-speed, high-G, but was eventually loosened to accommodate the same behavior happening at a low speed low G part of the flight envelope.

This is a hack in the truest sense of the word, because you'll notice the regs indicate the plane having to be within a certain point of appropriate trim; except in those flight regimes, the trim is artificially massaged from what the pilot set it to, to what MCAS thinks it should be, which is determined by the input of only a single AoA sensor.

In short, the airframe is aerodynamically flawed in some of the most fundamental ways known to the aviation community. It can work; given a correct MCAS system. There was no excuse, however, to hide this from both regulators and pilots.

Hope that explains things.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#238

Post by foldr »

jussij wrote: post #227
foldr wrote: post #213

Earlier quoted context omitted.

>because it also failed to tell that other pilot he was being ignored. It didn't fail to tell him. That's what the dual input alarm is for.

I will have to take your word on this dual input alarm as I have not read or seen any details on this alarm. Now if that alarm was raised then that suggests both pilots were in error as they both seemed to have ignore that alarm. However that was never the reason for my original reply. All I was replying to was idea that the flight control was doing some sort of averaging of the two pilot inputs . That to me just see…

>Now if that alarm

The sounding of the alarm is in the transcripts in the accident report.

The Airbus does average the inputs if both pilots are making inputs at the same time.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#239

Post by rsynnott »

notatoad wrote: post #54
dsfyu404ed wrote: post #15

Earlier quoted context omitted.

The industry is pretty homogeneous and somewhat of a revolving door between the few OEMs. What are the odds that the code on this plane is orders of magnitude worse (in terms of code quality) than every other similar bit of code in the sky? Edit. I should have to say this but I'm not defending Boeing here. I'm saying it's not at al unforeseeable that the other planes, even ones by other manufacturers are just as bad.…

My instinct is that you're probably correct, and most planes are probably riddled with similar problems and would look bad if they came under the same scrutiny as the 737 Max is currently under. For example, I remember after the 787 was launched there was a few stories in the press about the batteries catching fire mid-flight, but it turned out the designers and engineers had accounted for that possibility and it was…

> My instinct is that you're probably correct, and most planes are probably riddled with similar problems and would look bad if they came under the same scrutiny as the 737 Max is currently under.

0.5% of all 737 MAXes which exist have killed everyone on board. No other mass market production airliner in recent history has that sort of record, AFAIK.

Re: FAA Finds New Risk on 737 Max, Orders Boeing to Make Changes

#240

Post by rsynnott »

333c wrote: post #26
ngcc_hk wrote: post #9

Not going to trust that model, like dc10 (?). May work not engineer. But as customer, only get 1 life. Not as software beta tester.

How can you practically avoid a model of plane, other than avoiding all airlines that operate them?

> other than avoiding all airlines that operate them?

Answered your own question. Assuming Boeing doesn't just scrap this, most airlines will operate either it or the A320neo, not both.

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