United finds loose bolts on plug doors during 737 Max 9 inspections • Hacker News Board

Re: United finds loose bolts on plug doors during 737 Max 9 inspections

#521

Post by xyzzy_plugh » Tue, Jan 09, 2024, 3:34 AM UTC

bb88 wrote: post #504

vegetablepotpie wrote: post #456

Earlier quoted context omitted.

Does it make sense to degrade the performance of good software teams because bad software teams exist? Ideally we’d always have good software teams, but in the real world sometimes you have to build software with bad teams. Leaders have options, they can do things like reduce scope, increase budget, increase schedule, or full on abandon or cancel the project. These are all options available to leaders, but they requi…

> Ideally we’d always have good software teams, but in the real world sometimes you have to build software with bad teams. Here's a real, perhaps unexpected counterpoint. Say you have a good software team. How do they build good software with bad management?

They quit.

Re: United finds loose bolts on plug doors during 737 Max 9 inspections

#522

Post by thsksbd » Tue, Jan 09, 2024, 3:35 AM UTC

ethbr1 wrote: post #502

Robotbeat wrote: post #474

Earlier quoted context omitted.

I agree. I’m regularly critical of Boeing Defense (particularly space contracts where I’m a huge Boeing skeptic), but I think people are pretty off base if they think Boeing is just completely incompetent. Airliner safety is insanely good. Just vast seas of competence, but when there’s a super rare failure, the incorrect impression people get is that Boeing (or Airbus) is just full of incompetency. Almost nothing tha…

> Airliner safety is insanely good. Because I dug it up for another comment, commercial carriers operating under Part 121 (roughly: scheduled passenger and cargo operation) had 4 fatal incidents in the last 10 years. [0] Totalling 6 deaths. In 10 years of US commercial carrier aviation. One of those was literally 'the engine exploded and threw part of the turbine into the cabin (and also shredded some of the wing)'!!…

Ya but your sample size is way too small to measure the death rate. Aircraft deaths are rare, but flying is too.

The two MAX 8s that fell from the sky were 100% Boeing's fault and could have happened in the US. If 5% of airline traffic is in the US you can renormalize those hundreds of dead and you get dozens dead.

Re: United finds loose bolts on plug doors during 737 Max 9 inspections

#523

Post by bb88 » Tue, Jan 09, 2024, 3:36 AM UTC

johnnyworker wrote: post #514

bb88 wrote: post #488

Earlier quoted context omitted.

> Good software teams build quality into projects by introducing continuous integration, unit testing, creating feedback, and tightening these feedback loops. No. Good software teams are led by competent, technical management. Managers who aren't afraid to get down into the dirty details. Managers who aren't afraid to roll up their sleeves and write code if they need to. The process doesn't matter. The management of…

But that doesn't contradict the parent, does it? I'd say you both make good points.

Well... here's a thought experiment.

Let's say you have a bunch of school children and architects create a skyscraper. I've given both groups the process to design a skyscraper.

So in both cases, I should end up with a safe building?

Re: United finds loose bolts on plug doors during 737 Max 9 inspections

#524

Post by thsksbd » Tue, Jan 09, 2024, 3:36 AM UTC

bb88 wrote: post #513

ethbr1 wrote: post #502

Earlier quoted context omitted.

> Airliner safety is insanely good. Because I dug it up for another comment, commercial carriers operating under Part 121 (roughly: scheduled passenger and cargo operation) had 4 fatal incidents in the last 10 years. [0] Totalling 6 deaths. In 10 years of US commercial carrier aviation. One of those was literally 'the engine exploded and threw part of the turbine into the cabin (and also shredded some of the wing)'!!…

> Totalling 6 deaths. In 10 years of US commercial carrier aviation. Okay, awesome. But how much of that was luck with the 737 Max that they didn't crash on US soil by US airlines?

Most of it. Statistically. Its not hard to assign part of the deaths from the MAXes to the US.

Re: United finds loose bolts on plug doors during 737 Max 9 inspections

#525

Post by bb88 » Tue, Jan 09, 2024, 3:36 AM UTC

xyzzy_plugh wrote: post #521

bb88 wrote: post #504

Earlier quoted context omitted.

> Ideally we’d always have good software teams, but in the real world sometimes you have to build software with bad teams. Here's a real, perhaps unexpected counterpoint. Say you have a good software team. How do they build good software with bad management?

They quit.

Exactly!

Re: United finds loose bolts on plug doors during 737 Max 9 inspections

#526

Post by ethbr1 » Tue, Jan 09, 2024, 3:39 AM UTC

bb88 wrote: post #513

ethbr1 wrote: post #502

Earlier quoted context omitted.

> Airliner safety is insanely good. Because I dug it up for another comment, commercial carriers operating under Part 121 (roughly: scheduled passenger and cargo operation) had 4 fatal incidents in the last 10 years. [0] Totalling 6 deaths. In 10 years of US commercial carrier aviation. One of those was literally 'the engine exploded and threw part of the turbine into the cabin (and also shredded some of the wing)'!!…

> Totalling 6 deaths. In 10 years of US commercial carrier aviation. Okay, awesome. But how much of that was luck with the 737 Max that they didn't crash on US soil by US airlines?

How much was a rigorous safety regime and high quality training?

Re: United finds loose bolts on plug doors during 737 Max 9 inspections

#527

Post by thsksbd » Tue, Jan 09, 2024, 3:39 AM UTC

Scoundreller wrote: post #34

Syonyk wrote: post #20

Earlier quoted context omitted.

No, it's as insane as it reads. It means people were careless and sloppy during assembly. Think of it like seeing "one cockroach in your kitchen." It's not one cockroach. You just haven't opened up the rest of the walls.

Or it means the torque specs were a little too low, or too high and stripped, or the bolt threading was defective/spec’d wrong. Or bad metallurgy. Or the spec didn’t specify which order to tighten the bolts, so which direction you go causes different outcomes. Lots of stuff is assembled consistently and carefully “wrong”, but as specified.

So it's not the worker who ducked up, but there are loose bolts either way because the Walsh gang took over.

Re: United finds loose bolts on plug doors during 737 Max 9 inspections

#528

Post by bb88 » Tue, Jan 09, 2024, 3:41 AM UTC

darylteo wrote: post #384

ethbr1 wrote: post #371

Earlier quoted context omitted.

I expect even at its worst, software development could learn a lot from aircraft QA. Especially since most shops have pretty much tossed professional career QA out the window.

software development: what is QA?

That's where failed software devs / management go to.

Re: United finds loose bolts on plug doors during 737 Max 9 inspections

#529

Post by thsksbd » Tue, Jan 09, 2024, 3:41 AM UTC

t-writescode wrote: post #397

Syonyk wrote: post #20

Earlier quoted context omitted.

No, it's as insane as it reads. It means people were careless and sloppy during assembly. Think of it like seeing "one cockroach in your kitchen." It's not one cockroach. You just haven't opened up the rest of the walls.

When a junior software engineer drops a table in production, we don’t say the junior engineer was sloppy. We say the protections and process in place were bad. I don’t like how the sentence in this parent comment blames individuals for process problems.

It doesn't matter if the worker is sloppy and should have been fired, or if Boeings training is poor and should be improved.

Boeing has a responsibility to make sure its workers do their jobs as needed.

Re: United finds loose bolts on plug doors during 737 Max 9 inspections

#530

Post by lmm » Tue, Jan 09, 2024, 3:53 AM UTC

spaceywilly wrote: post #394

sparky_z wrote: post #275

Earlier quoted context omitted.

Which doesn't rule out, say, a design flaw that allows the bolt to loosen over time under certain circumstances.

The Max 9 has been in service since 2018 though, I think if it was a design issue it would have occurred before now. This seems like a Manufacturing QA “escape” to me. Some bolt was either not installed properly or not tightened to the proper spec, QA did not catch it

> The Max 9 has been in service since 2018 though, I think if it was a design issue it would have occurred before now.

That's a bit of a leap. If the bolts are e.g. too soft and have worn out in use, that would be a design issue that would only show up after a period of use.