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A Matter of Millimeters: The story of Qantas flight 32

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Re: A Matter of Millimeters: The story of Qantas flight 32

#161

Post by survivorBias »

magicalhippo wrote: post #157
f1shy wrote: post #120

Earlier quoted context omitted.

As an engineer I think a lot about tradeoffs of cost vs other criteria. There is little I can learn from nuclear or aviation industry, as the cost structure ist so completely different. I’m very happy that the costs of safety in aviation are very good accepted, but I understand that few people are willing to pay similar costs for other things like, say, cars.

We're making a niche B2B application, and this is very much it for us as well. Our customers are in a cutthroat market with low margins. We can't spend a ton on pre-analysis, redundancies and so on. Instead we've focused reduced the impact of failures. We've made it trivial to switch to an older build in case the new one has an issue. Thus if they hit a bug they can almost always work around it by going to an older b…

You can not. AI though, can be cheap enough to produce that. I wonder what happens if you take a b2b application and let it rewrite with AI to Nuclear Industry/ Aviation standards into a seperate repo. Then on fixes/rewrite the engineers take the "safety aware repository" as inspiration.

Re: A Matter of Millimeters: The story of Qantas flight 32

#163

Post by eastbound »

woutr_be wrote: post #143
abrookewood wrote: post #115

Earlier quoted context omitted.

Honestly, each and every one of those people should either be charged with reckless endangerments, put on an no-fly list or both. It really pisses me off when I see that. F**ing entitled idiots.

I remember there was this video of a plane in Russia that was on fire, multiple people died. And you see people walking away with their luggage, can’t help it think people would still be alive if it wasn’t for those who so urgently needed their suitcases.

People don’t follow the rules when they don’t trust their government for providing sane rules.

Case in point when you provide an example with Russia. Other example is Covid.

Re: A Matter of Millimeters: The story of Qantas flight 32

#165

Post by ogurechny »

The article is complex and well written, but I am a bit perplexed by the victorious tone and never-ending praise of safety. It resembles a sales pitch a bit too much, even though no one is selling anything. Maybe it's unintentional, and being around salesmen just does that to people.

If you are like me, you've probably said “hmm…” to yourself multiple times when certain things were mentioned, because those were things that actually didn't work (that they were left intact really boosts the credibility of the author). From calculation software that had never ever been tested with out-of-ordinary data to the computer keeping the broken engine running. From pure luck with fuel tanks being almost full and unable to explode to absence of any physical kill switch to stop the engine. An hour being generously available to go through ALL the checklists to clear the notifications. An hour of passengers and crew staying on top of the poodle of fuel hoping that nothing would ignite it. Finally, pure randomness in debris flying the way it did. It's not a story of “layers of safety” overlapping, it's a story of “layers of randomness” overlapping.

What would be really interesting is a distribution of outcomes for all possible trajectories of debris, i. e., how (un)lucky they actually were. I guess corporations don't release models like those to the public.

Also, that special chamber for oil filter requiring precise drilling of a perfectly fine pipe seems “ewww” to me. It is not serviceable anyway without reinstalling everything from scratch, as far as I understand, why not make it a single piece?

Re: A Matter of Millimeters: The story of Qantas flight 32

#167

Post by masklinn »

danhor wrote: post #160
masklinn wrote: post #135

Earlier quoted context omitted.

As it turns out (and as much as we wouldn’t want them to) human lives are still subject to cost/benefit analysis. An airliner is a lot of lives, a lot of money, a lot of fuel, and a lot of energy. Which is why a lot has been invested in training, procedure, and safety systems. Cars operates in an environment which is in most ways a lot more forgiving, they’re controlled by (on average) low-training low-skill non-redu…

I wouldn't say it's simply cost-benefit analysis. It's also scale of accidents. A whole lot more people die from car accidents, yet there are few reports on national news on accidents. So fewer people care. Meanwhile each time there is an aviation disaster, 100s of people die and it's all over the news for weeks. Similarly with train accidents and nuclear accidents. There where only 2 very large ones but they still h…

> I wouldn't say it's simply cost-benefit analysis. It's also scale of accidents.

But that is cost/benefit analysis. When any accident can kill hundreds and do millions to billions in damage besides (to say nothing of the image damage to both the sector and the specific brand), the benefit of trying to prevent every accident is significant, so acceptable costs are commensurate.

Re: A Matter of Millimeters: The story of Qantas flight 32

#168

Post by kergonath »

peteradio wrote: post #55
V__ wrote: post #39

I'm wondering why the tolerances for the oil pipe were so small in the first place. Why not make the pipe one or two mm thicker?

Because its dead simple to machine a center and the designer did not factor in machinist/engineer/qa/facility incompetence.

You don’t need any such incompetence in this case, as explained in the article, though it does help and that specific facility had several issues. The tube was built to spec, it’s the specs that were not what they should have been.

The failures were more with the whole process (like the reference points with different tolerances and the inadequate paperwork) rather than machinist incompetence. They are just the guys at the bottom.

Re: A Matter of Millimeters: The story of Qantas flight 32

#169

Post by EVa5I7bHFq9mnYK »

aaronmdjones wrote: post #166
EVa5I7bHFq9mnYK wrote: post #162

With the engine ruptured, still operating and the fuel leaking, how did they know the whole thing is not gonna explode at any moment?

They didn't, which is why they shut it down.

I've read the ruptured engine was still operating for 3 hours after the plane landed.

Re: A Matter of Millimeters: The story of Qantas flight 32

#170

Post by kergonath »

rgmerk wrote: post #61
nradov wrote: post #23

And this is why fully autonomous flight control systems won't be certified for airliners in our lifetimes. While autonomous systems are capable of taking off, navigating to a destination, and landing they are largely incapable of handling major emergencies. It's impossible for engineers to foresee every possible failure mode and program for it.

It’s worth pointing out that there are also plenty of airliner crashes that are attributed to pilot error.

Plenty compared to the set of airliner crashes, which is very small. There are also a lot of near misses that don’t turn into crashes precisely because of pilots being good at their jobs.

For AI to replace pilots, you don’t need to prove that sometimes humans fuck up. You need to demonstrate that AI would fuck up less often and in a more acceptable way. This requires looking at the big picture, not only bad cases.

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