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

nytimes.com

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

#171

Post by m_mueller »

kdazzle wrote: post #142

> It never tested a malfunctioning sensor, according to the three officials. That one popped out to me. Man. Lots to learn. > Boeing continued to defend MCAS and its reliance on a single sensor after the first crash, involving Indonesia’s Lion Air. Also...how? So many non safety critical services use a load balancer and at least a couple of servers because who can trust just one thing working perfectly all the time?

Another one that popped out: test pilots were pushed to simulator-only by management, with simulators apparently being incomplete with regards to MCAS behavior. Bean counting and incompetence abound in safety critical areas of airplane design - I will think twice before stepping in another recent model of Boeing.

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

#173

Post by LoSboccacc »

deanCommie wrote: post #162
LoSboccacc wrote: post #158

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?

it was just a bunch of examples of stuff that was specifically done on top of my other job resps. also, not every place is the silicon valley and not every company is a fortune 500, plus some perspective about relative worth also applies - i.e. the automation stuff was calculated in time saved by the Indian based testing team, which reduces the raw impact.

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

#174

Post by m_mueller »

jaggirs wrote: post #64
cmurf wrote: post #41

Boeing engineers did consider [MCAS activation due to failed sensor] in their safety analysis of the original MCAS. They classified the event as “hazardous,” ... could trigger erroneously less often than once in 10 million flight hours. The incuriosity of all parties to an event categorized as hazardous is astonishing. Boeing says it's a system that's completely transparent to the pilot, and therefore there is no nee…

If the pilots had recieved training, then they could be a backup. So probably whoever did that safety analysis was assuming pilots would know how and when to turn off the system, but the pilots in fact didn't know this system existed at all.

Also don't forget that they also jiggered the switches to not be able to shut off MCAS alone, only together with automated trim.

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

#175

Post by FartyMcFarter »

mikeash wrote: post #126
bwbw223 wrote: post #80

Earlier quoted context omitted.

Would you not need three sensors? With only two, wouldn’t it be difficult to determine which is correct?

You don’t need to determine which is correct. MCAS is not a safety critical system and can just shut down if the sensors disagree.

That assumes the sensors are likely to disagree if they're broken, which may not be true.

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

#176

Post by 01100011 »

danols wrote: 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 blame for all of this.

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

#177

Post by _ph_ »

tacosx wrote: post #87
CamperBob2 wrote: post #48

Earlier quoted context omitted.

Anything short of admitting "we fundamentally screwed up, and are rethinking the poor decision to pair this engine with this airframe" Can you cite the basis for this often-expressed sentiment? There's absolutely no reason why a properly-designed and -vetted MCAS system wouldn't have been a perfectly acceptable solution to any handling irregularities caused by the engine configuration. The idea was fine. The fault wa…

It's not impossible to make it work, and in the future I'd expect more and more automated systems in planes for sure. But you have to recognize the whole engine hack is just a convoluted workaround to avoid as much pilot training as possible. The entire goal of the project seems to be to avoid ever training pilots for as long as possible. It's a brand new plane, the newest plane on the market, and the first thing you…

The problem with training pilots for a new machine isn't the training itself but rather, that a pilot is rated for one machine type only. If the MAX had a different type rating, MAX pilots would no longer be rated for the non-MAX 737. There are some larger US carriers which are 737 only, partly so that all pilots are trained for all of the machines. Having to split the fleet into two types would have a huge impact on business. Most likely these carriers would avoid getting any MAX as long as possible.

I don't know what is the correct answer to the problem, but clearly good safety regulations are trapping some carriers and Boeing. Sooner or later Boeing will have to build a true successor to the 737 (and I guess, they now wish they had sooner)

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

#178

Post by Haga »

GoToRO wrote: post #118
kejaed wrote: 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…

engineers overseeing this work There the thing: nobody wants to pay engineers on par with managers. Maybe one can not manage something he/she can not understand.

Leaky systemic process abstraction.

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

#179

Post by _ph_ »

pseingatl wrote: post #172

Why didn't they just bring back the already-certified 757 instead of stretching the 737?

The problem isn't the certification of the plane, it is the certification of the pilot. A 757 or a true successor to the 737 would have meant that pilots would have to be certified for the new plane - and that means they lose their certification for the plain 737. The MAX is targetted at carriers which already have large fleets of 737 and the idea was that the same pilot could fly both.

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

#180

Post by Haga »

djsumdog wrote: post #76
ficklepickle wrote: post #52

This whole plane sounds like any ugly hack. They slapped very different engines on an existing airframe. Then, when it inevitability exhibited undesirable behaviour, they tried to paper over the cracks. Then they hid this information from their customers, regulatory agencies and the pilots. It makes me wonder if there are other issues with the Max that the public doesn't know about yet. I hope a thorough review of Bo…

The sad thing is that we'll probably see this plane fly again by the end of the year, because the millions of dollars in retrofits will still be cheaper than having to scrap all existing planes. We have no idea what other potentially lethal corners have been cut. What if they go back into service, after several months of retrofitting all of them at Boeing maintenance hangers, and then the following year there are two…

It will fly only to be voted down with customers feet. I know a lot of people who looked on the plane type for the first time during their holiday bookings. This plane is finished.
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