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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

#131

Post by rswail »

MBCook wrote: post #79
metadat wrote: post #10

An amazing recovery, there's even an Air Crash Investigations episode about it: https://imdb.com/title/tt3234896/

Love that show. Makes me wish we dealt with software even a tiny bit like that. Checklists alone for troubleshooting common customer problems would save so much hassle. But so many companies (including mine) still work on more of the “heroic” model where it’s up to individuals to just learn the hard way through helping lots of customers and noticing patterns.

I'm trying to introduce SRE as a practice in to my organization. We don't have anywhere near the safety requirements of aviation or medical or power generation software, but our operations do affect thousands of people around the world.

Getting people to understand that SRE is a code of practise and an overall approach has been very difficult, even with the so-called "QA" team, who think their job ends when the latest upgrade is deployed.

We do work in public transport, and the best solution I've found so far, is when they say they're "done", I ask them whether they are willing to stand at the railway station at peak hour and explain to passengers why they can't get home on time (or to work).

The usual result is that they go away and think about it and there is more testing done. But getting that to be a standard approach and way of thinking is very difficult, especially when product owners and project managers are only focussed on the next milestone/payment.

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

#132

Post by ponector »

spenczar5 wrote: post #68
WalterBright wrote: post #66

Earlier quoted context omitted.

Airliners face constantly changing specifications. No two airliners are built the same.

Do you mean no two individual planes? Like two 767s made a month apart, do you mean they literally would have different requirements?

I think they means that airplanes are made in different versions, catered to particular airline. Also planes are constantly updated.

Two 767 made few months apart will have initial difference, like two different versions of java 8 SDK.

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

#133

Post by ChickeNES »

brutusborn wrote: post #118
camkego wrote: post #27

This article highlights the dangers from fake/illegitimate/non-oem aircraft replacement parts that are being used to repair aircraft. https://www.reuters.com/business/aerospace-defense/engine-ma... Doesn't make me feel comfortable about flying.

It doesn’t really specify the risk though, the parts may not be critical. I would hope regulations require independent certification for critical parts, but I’m scared to look.

Sometimes non-critical parts can cause a disaster though, as in Swissair 111, where arcing in the in-flight entertainment system led to a fire that quickly doomed the plane.

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

#134

Post by solids »

modernpacifist wrote: post #40

I don't know about others, but I can't help but smile when I read the detailed series of events in aviation postmortems. To be able to zero in on what turned out to be a single faulty part and then trace the entire provenance and environment that led to that defective part entering service speaks to the robustness of the industry. I say that sincerely since mistakes are going to happen and in my view robustness has l…

I agree, and also I enjoy the attitude. While in my profession the postmortems goal is finding who to blame, here the attitude is towards preventing it to happen again, no matter what. Or at least that’s how I feel.

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

#135

Post by masklinn »

uselpa wrote: post #126
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.

Cars might not be the best example, since human lives are at stake, as in aviation. Unless you work on Teslas autopilot, it seems. But yes, backups and restores are often good enough.

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-redundant crews, they’re much more at risk of “enemy action”, the material stresses are in a different realm, and they’re much, much more sensitive to price pressure.

Hell, the difference is already visible in aviation alone, crop dusters and other small planes are a lot less regulated amongst every axis than airliners are.

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

#136

Post by gumby »

MBCook wrote: post #73
gumby wrote: post #34

30 years ago I was in an emergency landing due to engine failure situation (flight attendants take away your shoes, practice crash position, rearrange the passengers etc) and the thing that stuck out the most for me was that everybody did as they were told. No self righteous people; it was clear to everyone why there are flight attendants aboard and that they were key to your survival. The evacuation was orderly, tho…

You’re not supposed to take anything on the slides. No luggage. No shoes. Just you. But it is ignored. Which is sad, people could really get hurt. Your right though the fact as many people comply as they do is kind of incredible given how people act in other situations.

They took out per shoes away so that was that. According to a parallel reply, they no longer do that.

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

#137

Post by jstanley »

modernpacifist wrote: post #40

I don't know about others, but I can't help but smile when I read the detailed series of events in aviation postmortems. To be able to zero in on what turned out to be a single faulty part and then trace the entire provenance and environment that led to that defective part entering service speaks to the robustness of the industry. I say that sincerely since mistakes are going to happen and in my view robustness has l…

> robustness has less to do with the number of mistakes but how one responds to them

It must have something to do with the number of mistakes, otherwise it's all a waste of time!

It's all well and good responding to mistakes as thoroughly as possible, but if it's not reducing the number of mistakes, what's it all for?

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

#138

Post by Grimburger »

> By specifying an landing weight in excess of the maximum, the system logic changed to apply the operational coefficient only once — for unrelated and obscure reasons — and lo and behold, when he ran the numbers this time, the computer said they could just barely land on any of the 4,000-meter runways at Singapore Changi Airport, with only 100 meters to spare. It wasn’t much, but with no better runways anywhere nearby, it would have to do.

Hacking overflows in an emergency, topnotch.

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

#139

Post by Grimburger »

hugh-avherald wrote: post #82
sundvor wrote: post #54

Earlier quoted context omitted.

Yep, they were very heavy and needed to land essentially at stall speed - which they basically did seeing as the stall warning chimed in moments before touch down - in order to allow for as much space as possible to stop the plane. I took from the article that their calculations were kind of hacked together with a number of overrides, so I guess they erred on the side of caution in case any of the assumptions needed…

> especially the pilot Worth noting that there was an unusual flight crew: 3 captains (one to check the captain's proficiency, and another to check the checker's proficiency) plus the first and second officers.

Plus the off-duty one upstairs watching the tail camera on the entertainment console. Article says 140 years of combined experience between them which is more than impressive. Airbus really couldn't have hoped for a better crew for this to eventually happen to.

One of my favourite things about the A380 is that in-flight live feed from the tail, surprised more planes don't do it. Offers visual detail of the entire topside and a lot of information that might not otherwise be available.

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

#140

Post by jnsaff2 »

aunty_helen wrote: post #35

My first job was working at a mro that overhauled engines a bit smaller than the Trent 900s but same principles apply. I built qa software to digitize the forms and signature process like what’s mentioned in the article as having not correctly been signed off on. I ate lunch with repair engineers that had dark wells of knowledge about the engines they worked on. They could talk so deep on a subject that lunch break w…

I had a small experience with RR as a company through a contract. Including some time spent in Derby.

The things I saw left me question how any innovation could happen at all in there or why we did not have a much higher rate of fuck-you-shima per year or how the hell plane engines are not exploding daily.

IIRC the B777 engine controllers are still m68k. Discontinued in 1995.

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