Latest 737 Max Fault That Alarmed Test Pilots Rooted in Software • Hacker News Board

Re: Latest 737 Max Fault That Alarmed Test Pilots Rooted in Software

#131

Post by linuxftw » Sat, Jul 27, 2019, 2:39 PM UTC

tus88 wrote: post #28

burfog wrote: post #18

Earlier quoted context omitted.

It's proper. This is exactly how you do things with life-critical embedded software. You detect when things are crazy, which of course shouldn't happen but nevertheless does, and you react in a way that is hopefully not disastrous. The alternative is to ignore the problem. Sensors go bad. Actuators go bad. Voting hardware goes bad. Message routing goes bad. Even the RAM sometimes goes bad. When the hardware is failin…

The way I read it they are not detecting malfunctioning sensors, but essentially a computer fault caused by it's inability to deal with erroneous input. Rather than fixing the computer, they are essentially wrapping a great big try/catch around it....good God.

But what's erroneous input? A bit is flipped? A .1V increase over 0 makes it a logical 1, when it should be .3V? I mean, this is the domain of computer/electrical engineers in the first place, to prevent these kind of problems. This is what happens when you outsource your critical components to 3rd parties.

Re: Latest 737 Max Fault That Alarmed Test Pilots Rooted in Software

#132

Post by linuxftw » Sat, Jul 27, 2019, 2:42 PM UTC

jeremyjh wrote: post #118

marcyb5st wrote: post #98

Earlier quoted context omitted.

Agreed. However, the worst part is the FAA. Specifically, what baffles me is the massive hand-wave they did on this considering it is one of their mandates to check flight-worthiness of Airplanes/Airlines. I hope all the other agencies worldwide will double check all the prior certifications issued by the FAA, because all their credibility is gone. Especially considering the US was the one the last countries to groun…

Regulatory capture. After their careers at the FAA they will go work at Boeing.

Do you think regulatory capture actually exists? If so, why is the pharmaceutical industry immune?

Re: Latest 737 Max Fault That Alarmed Test Pilots Rooted in Software

#133

Post by selectodude » Sat, Jul 27, 2019, 2:45 PM UTC

acqq wrote: post #127

DanHulton wrote: post #110

Earlier quoted context omitted.

I see this sentiment a lot, but its kind of surprising. Traditional wisdom states the opposite - never do a full rewrite, you lose the years of buit-up fixes and edge cases and have to learn from scratch in too many places. Despite everything, I still don't think the solution to the 737 MAX problem is to start over. The base problem that Boeing has its actually their terrible engineering culture, the one that values…

The problem here is that what Boeing is selling ("737 that spends significantly less fuel and doesn't need recertification") simply can't be made safe. Whatever results from the marketing driven goal (selling something that doesn't and can't exist in reality) will remain unsafe as long as all the "already sold features" are preserved. So it's not if they should "start from clean" but just accept the need for the new…

The funny thing is this plane already exists. It’s called the 757 and Boeing stopped making it 15 years ago because the airlines wanted stretched 737s far more than they wanted the clean sheet redesign.

Re: Latest 737 Max Fault That Alarmed Test Pilots Rooted in Software

#134

Post by linuxftw » Sat, Jul 27, 2019, 2:48 PM UTC

ninth_ant wrote: post #95

anticristi wrote: post #58

Before upgrading to the latest Ubuntu, I like to wait for a few months until my friends confirm that it's for the better. I guess I would do the same for the MAX. I can't imagine what it must be like to be one of the first pilots to fly the MAX once the grounding is lifted. Can pilots refuse to fly a specific plane "for a few months, 'cause I have kids waiting for me home"?

There were almost 400 delivered by the time it was grounded, some of them in service since 2017. Yes there were two high profile failures and this failure rate is extremely out of the norm by the very stringent standards of aviation — but these are not sudden-unavoidable-death machines that gets sensationalized.

That's exactly what they are. How many planes have malfunctioned in the same way and haven't nose-dived into the ground? So far, 0 planes that have had this issue haven't been lost (first plane had the issue, was recovered using non-standard procedures, then same plane killed everyone, even after sensor was replaced!)

Re: Latest 737 Max Fault That Alarmed Test Pilots Rooted in Software

#135

Post by LifeLiverTransp » Sat, Jul 27, 2019, 2:57 PM UTC

mtgx wrote: post #91

taneq wrote: post #54

Earlier quoted context omitted.

Yeah, it’s a nice way of saying “this is a hack”.

Move fast and kill things. At least that seems to be the motto of self-driving carmakers, too.

Hey, just add a "I-the-User-m-Responsible" dead-men-switch to the plane, that the pilot has to press and you will be fine.

Regards the Lawyers department for engineering & software hacks

Re: Latest 737 Max Fault That Alarmed Test Pilots Rooted in Software

#136

Post by adrianN » Sat, Jul 27, 2019, 3:16 PM UTC

freehunter wrote: post #113

adrianN wrote: post #106

Earlier quoted context omitted.

No, it's not. Certification is an extremely expensive process with dubious benefits for safety. Why would you change hardware that has worked fine if it can fulfill your requirements?

Because it obviously did not work fine and does not fulfill the requirements. What seems to have dubious benefits for safety is lying to the regulators and shoehorning new processes into old technology. Because hundreds of people have died from that exact thing, just on this one airplane.

The airplanes didn't crash because the computer was too slow. They crashed because safety critical data was read from a sensor without redundancies.

Re: Latest 737 Max Fault That Alarmed Test Pilots Rooted in Software

#137

Post by ricardobeat » Sat, Jul 27, 2019, 3:35 PM UTC

Someone1234 wrote: post #123

I'm surprised nobody is discussing this paragraph from the article: > The failure scenario was known previously and had been assessed in a safety analysis when the plane was certified before entering service in 2017. At that time, Boeing concluded that pilots could overcome the nose-down movement by performing a procedure to shut off the motor driving the stabilizer movement. This isn't a new fault. Boeing certified…

I’ve only recently started following the air industry more closely, but isn’t it ironic that Boeing, the one on the “direct control” side vs computerized systems from AirBus, is the one now suffering from software and automation failures?

I wonder if it might be a consequence of being a late adopter, and rushing the development of systems they never had before.

Re: Latest 737 Max Fault That Alarmed Test Pilots Rooted in Software

#138

Post by ant6n » Sat, Jul 27, 2019, 3:52 PM UTC

ubersoldat2k7 wrote: post #77

jacobush wrote: post #55

Earlier quoted context omitted.

There is so much of U.K. which is incredible and depressing at the same time. Completely pummelled by war, (receiving no aid like West Germany did) they managed to, in 1949, release a Space Age passenger commercial airliner, defining the genre. It looks modern even today. Yet, fumbled the ball. They also had a space program, closed it down after their first satellite, which was a success. Concorde! (With France.) It…

Last week I was at Munich, with +40 other Europeans: French, Spanish, Italian, German, Dutch, Swedes and of course Irish and British. As I was sipping my beer at a biergarten I realized we were all speaking English, in Germany, surrounded by people whose native language wasn't English, right when Brexit is about to happen, just when any British could say: we won. But no, as you said, they just fumbled the ball, again…

I thought the US won..

Re: Latest 737 Max Fault That Alarmed Test Pilots Rooted in Software

#139

Post by aurelwu » Sat, Jul 27, 2019, 4:03 PM UTC

adrianN wrote: post #136

freehunter wrote: post #113

Earlier quoted context omitted.

Because it obviously did not work fine and does not fulfill the requirements. What seems to have dubious benefits for safety is lying to the regulators and shoehorning new processes into old technology. Because hundreds of people have died from that exact thing, just on this one airplane.

The airplanes didn't crash because the computer was too slow. They crashed because safety critical data was read from a sensor without redundancies.

But now during simulations test pilots apparently found situations where the computer was too slow to handle their input in adequate time. So while the crash was not the caused by this problem, there seems to be a problem.

Re: Latest 737 Max Fault That Alarmed Test Pilots Rooted in Software

#140

Post by ulfw » Sat, Jul 27, 2019, 4:10 PM UTC

ricardobeat wrote: post #137

Someone1234 wrote: post #123

I'm surprised nobody is discussing this paragraph from the article: > The failure scenario was known previously and had been assessed in a safety analysis when the plane was certified before entering service in 2017. At that time, Boeing concluded that pilots could overcome the nose-down movement by performing a procedure to shut off the motor driving the stabilizer movement. This isn't a new fault. Boeing certified…

I’ve only recently started following the air industry more closely, but isn’t it ironic that Boeing, the one on the “direct control” side vs computerized systems from AirBus, is the one now suffering from software and automation failures? I wonder if it might be a consequence of being a late adopter, and rushing the development of systems they never had before.

The only reason Boeing is in the “direct control” business is because their best seller is from the 1960s and they don’t dare touch it. Their newer wide bodies 777 and 787 are fly-by-wire and in the latter case even fully electric to a fault.