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Boeing Built Deadly Assumptions into 737 Max, Blind to a Late Design Change

nytimes.com

181–190 of 280 posts

Re: Boeing Built Deadly Assumptions into 737 Max, Blind to a Late Design Change

#181
post #85

The day someone very high up the corporate ladder truly gets held responsible for this type of greed & negligence and will be put a way for a long prison sentence would be a good day for society. But I am not holding my breath... But I hope that the CEO Dennis Muilenburg deep down understands he seriously fuxxed up real bad and every now and then is having a hard time falling a sleep in his $10M mansion knowing that…

Your comment makes it sound like you believe there was a single person with nefarious intentions or criminal negligence who chose to put lives at stake in exchange for profits. That is almost certainly not what happened. It is more likely a system of procedures and policies which failed. The company should take the hit, but unless an investigation reveals otherwise, I see no reason a single individual should take the…

> That is almost certainly not what happened. It is more likely a system of procedures and policies which failed. The company should take the hit, but unless an investigation reveals otherwise, I see no reason a single individual should take the blame for all of this.

Aren't the insane compensations of executives justified by their "great responsibility"? So I think it makes them eventually responsible for what their companies do.

Re: Boeing Built Deadly Assumptions into 737 Max, Blind to a Late Design Change

#182
post #27

I really see this as a failure of the Systems Engineering process. With so many people unaware of the impacts of the changes, it’s up to the systems types to have the big picture view and make sure these sorts of things are taken into account. Especially if as the article says a failure of the AOA sensor on the system would be Hazardous (looks like it was Catastrophic when paired with MCAS in retrospect), that would…

I don't know if one could say a failure of the Systems Engineering process. One could also say it is a situation where management, regulatory and market constraints became so unwieldy that there was simply no way Systems Engineering could possibly satisfy the requirements. Sure, it's a failure to push back again this but that seems a bit different.

Management and "the market" were providing faulty feedback that engineering couldn't push back against, no matter how much force was applied.

Re: Boeing Built Deadly Assumptions into 737 Max, Blind to a Late Design Change

#183

Earlier quoted context omitted.

> There the thing: nobody wants to pay engineers on par with managers I used to think like that but I learned in time that the core issue is that engineers rarely know how to present their job in terms of monetary benefit during salary negotiations. i.e. as an automation engineer I led an initiative that saved a previous employer more than 60k€ yearly using automation and optimizing other validation workflows. as pri…

I assume these must be small examples on a long list of accomplishments, because 30k/year doesn't seem like it's enough to offset your salary. I have to imagine the impact of a principal engineer should be measured in the 10-100x of their salary?

That's some pretty impressive ingrained bias towards rent-seekers. Why not 1.1x or the board can try doing the work?

Re: Boeing Built Deadly Assumptions into 737 Max, Blind to a Late Design Change

#184
Great article. But for me there's a huge question being left unanswered, like the elephant in the room:

Why did exactly did the engineers/test pilots feel the need to "enhance" the original MCAS with the new, more powerful version that worked at lower speeds? What did they know? I doubt they did it for the hell of it. And therefore, what has changed that that enhanced functionality is now no longer necessary, and it's fine that MCAS is being returned to its original, more subtle implementation?

These things just don't add up for me and Boeing's constant pronouncements that they did nothing wrong, everything was fine, and now they're fixing it so everything will be even more fine ring very hollow indeed. I would almost like to see everyone involved in this subpoenaed so the public can learn the truth of what, exactly, took place.

Until we have some answers, especially to my main one - what was so bad about the airframe's handling that it was necessary to massively increase the power of the MCAS system, but is now apparently not necessary anymore and it's fine for them to nerf it - I don't think I'll be flying on a MAX.

Re: Boeing Built Deadly Assumptions into 737 Max, Blind to a Late Design Change

#185

Earlier quoted context omitted.

But MCAS was added because the plane doesn't handle well in some situations.

It handles differently, yes. That could be handled with a bit of training.

It will not satisfy the current handling requirements, hence either making it completely unairworthy or a special category with vastly different handling from usual passenger-rated airplanes.

Re: Boeing Built Deadly Assumptions into 737 Max, Blind to a Late Design Change

#186
post #114
post #104

Earlier quoted context omitted.

the airplane did not have stable flight characteristics because of its physical design. that’s a hardware problem. MCAS only exists because of that hardware problem. the fact that boeing also did not train or tell pilots about MCAS, in order to make the airplane more financially appealing by retaining the 737 type rating, is a separate (also bad) issue.

Citation needed. FAR 25 applies to all transport category aircraft. The section on stability (§§ 25.171 - 25.181). In exactly what manner is the airplane not stable, with or without MCAS?

It's not stable in a "crashes into the ground and kills everyone on board in spite of the best efforts of its pilots" manner.

In exactly what manner is it not obvious this is not an acceptable design outcome?

Re: Boeing Built Deadly Assumptions into 737 Max, Blind to a Late Design Change

#187
Empires destroy institutions.. they hollow them out until are barely cloths for one figure residing within. Proofing something to an institution is hard. Proofing something to one person is "easyish". The problem is not that one plane manufacturers internal culture allowed falling behind, but that this rot and decay bypassed controlling institutions, because these where hollowed out for empire reasons. You can not defeat this problem unless you solve the root node. Which are hidden deals instead of proper procedure replacing the physics of capitalism.

Re: Boeing Built Deadly Assumptions into 737 Max, Blind to a Late Design Change

#188

Earlier quoted context omitted.

I believe the airplane is aerodynamically stable even at high alpha. What it fails in certification is the requirement to have continually increasing pitch feedback forces. I believe the pitch feedback forces are still in the stable region, just too low. This is not a flying wing or intentionally unstable airplane (as the F-16).

I believe the airplane is aerodynamically stable even at high alpha. That would put you at odds with Boeing's test pilots.

No it wouldn't (or "citation needed" if so).

The issue is not that the airplane shows negative or neutral aerodynamic pitch stability, it's that it does not exhibit an increasing stick force gradient, as required by certification rules.

https://airfactsjournal.com/2019/03/can-boeing-trust-pilots/

Re: Boeing Built Deadly Assumptions into 737 Max, Blind to a Late Design Change

#190

I posted this as a comment the other day in another Boeing and MCAS discussion. In my research into the topic the saddest bit of information I've seen is the image of the black box data for the flight (the first crash): https://i.imgur.com/WJuhjlO.png You can see from the graph that in the final minutes and seconds, the pilot put insane amounts of force on the control column (aka the yoke) to try to pull the plane ou…

If the pilots were putting that much force on the yoke it is pretty apparent that the pilots really truly wanted the plan to do what they asked of it.

I am curious what scenarios the designers of the plan drove then to not trust that the human in the seat really has no idea what they are doing. Was the ignoring the wishes of the pilot and attempt to prevent a crazed irresponsible and unlicensed idiot from doing something? These are trained humans why does the computer totally ignore there efforts?

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