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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

#121

Post by modernpacifist »

mzi wrote: post #109
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…

It took hundreds of subject experts from ten organizations in seven countries almost three years to reach that conclusion. Here at HN we want a post mortem for a cloud failure in a matter of hours.

> Here at HN we want a post mortem for a cloud failure in a matter of hours.

I'll go one further - I've yet to finish writing a postmortem on one incident before the next one happens. I also have my doubts that folks wanting a PM in O(hours) actually care about its contents/findings/remediations - its just a tick box in the process of day-to-day ops.

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

#122

Post by Gibbon1 »

defrost wrote: post #93
dataflow wrote: post #87

Earlier quoted context omitted.

Why in the world do you have to take your shoes off before going down the slides? I could understand jackets or jewelry, but shoes?

As silly as it might seem, you do something enough times and oddball rare things happen .. this is an instruction intended to reduce: * shoes | boots with sharp objects embedded in soles (glass, bent nails) * extra spikey high heels, * work boots with hard edged metal hooks for laces, (etc) causing damage to both inflatable slipways and to other passengers. How often has a passenger going down an emergancy slide caus…

And if something gets caught on the slide as you go down you could fall a dozen or more feet onto hard asphalt. Friend fell on a slide and got a compound leg fracture.

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

#123

Post by cwalv »

girvo wrote: post #64
Horffupolde wrote: post #62

Earlier quoted context omitted.

If 200 people died after a db instance crashed, software would be equal in that regard.

To prove this, software that deals with medical stuff is somewhat more like aviation.

Also, aviation and software aren't orthogonal. E.g., the article mentioned that part of the reason the pilot was able to sustain a very narrow velocity window between stall and overrunning the runway was because of the A380's fly by wire system.

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

#124

Post by polonbike »

defrost wrote: post #93
dataflow wrote: post #87

Earlier quoted context omitted.

Why in the world do you have to take your shoes off before going down the slides? I could understand jackets or jewelry, but shoes?

As silly as it might seem, you do something enough times and oddball rare things happen .. this is an instruction intended to reduce: * shoes | boots with sharp objects embedded in soles (glass, bent nails) * extra spikey high heels, * work boots with hard edged metal hooks for laces, (etc) causing damage to both inflatable slipways and to other passengers. How often has a passenger going down an emergancy slide caus…

Also, try to swim/stay afloat with shoes ... Apart from young athletes, most people will drown within a minute

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

#125

Post by uselpa »

cedivad wrote: post #112
WalterBright wrote: post #65

Earlier quoted context omitted.

As a former Boeing engineer, other industries can learn a great deal from how airplanes are designed. The Fukushima and Deepwater Horizon disasters were both "zipper" failures that showed little thought was given to "when X fails, then what?" Note I wrote when X fails, not if X fails. It's a different way of thinking.

> When my AoA sensor fails, then what? crickets, let's just randomise which sensor we use during boot, that ought to do it!

Epic fail indeed, costing many lives.

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

#126

Post by uselpa »

f1shy wrote: post #120
WalterBright wrote: post #65

Earlier quoted context omitted.

As a former Boeing engineer, other industries can learn a great deal from how airplanes are designed. The Fukushima and Deepwater Horizon disasters were both "zipper" failures that showed little thought was given to "when X fails, then what?" Note I wrote when X fails, not if X fails. It's a different way of thinking.

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.

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

#127

Post by Kosirich »

tgbugs wrote: post #110

My internal alarm bells started going off as soon as I read about datum AA and datum M. Shouldn't it be possible if not standard practice for the design software to issue a giant warning if you have a part that is defined by two datums that are almost but not quite the same? If they aren't the exact same datum then something like this will inevitably happen.

There is nothing wrong with 2 datums, the issue is that during machining this is not "a part" but an assembly that moves. There are so many failings from my POV in the manufacturing process and verification of the part, which is summarized nicely by the following quote:

. Furthermore, initial inspections at the start of the production run were supposed to verify that the manufacturing process was creating products that satisfied the “design intent,” but the initial products were checked against the manufacturing drawings, not the design drawings.

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

#129

Post by switch007 »

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 can only hope that the software/tech industry can one day be an equal in this regard

I’d love to be an engineer with unlimited time budget to worry about “when, not if, X happens” (to quote a sibling comment).

But people don’t tend to die when we mess up, so we don’t get that budget.

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

#130

Post by rswail »

dabiged wrote: post #119
grecy wrote: post #44

Earlier quoted context omitted.

> As for Qantas, near the end it mentions the plane was repaired at great cost Indeed. Qantas has been ranked the safest airline int he world almost every year since forever [1] I clearly remember when QF32 happened and everyone was utterly shocked. That simply DOES NOT happen to Qantas. [1] https://www.forbes.com/sites/laurabegleybloom/2023/01/03/ran...

QANTAS has, for the last 10+, had a CEO who was not part of this culture and did everything he could to drive costs down. He laid off huge swaths of engineers, outsourced key maintenance contracts to the lowest bidder and left the airline with an aging fleet that needs billions spent to replenish. He was recently fired by the board for essentially destroying the reputation of the airline within Australia, with their…

The destruction of Qantas as a quality airline is entirely driven by exactly the same MBA/shareholder-value bullshit that destroyed Boeing and others.

Financial engineers should be banned from operating businesses. They are not focused on the quality of the business, from which profits are derived. They work backwards from their financially engineered results to drive down "costs", even if those "costs" are entirely essential to the operation of the business.

Qantas (and its subsidiary Jetstar) are having to recover their engineering, customer service, and other "costs" to actually achieve the operating business that their expensive tickets require. Currently they are being priced out of operating in Asia, not because they have too expensive operations, but because their board and CxOs were entirely driven by shareholders, not the ongoing operation of the business.

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