Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

A Matter of Millimeters: The story of Qantas flight 32

admiralcloudberg.medium.com

Post reply on HN
Print view View original

101–110 of 307 posts

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

#101

Post by mannykannot »

stevepeg wrote: post #45
XorNot wrote: post #21

The one thing which sticks out to me is the ECAM system including a baked corrective message of "open fuel transfer valves" due to the imbalance. That seems like an odd message to include in an emergency action system, which by definition is only active in unexpected situations. Is there really no system to confirm if a fuel leak is happening?

A320/330/340/350 driver here (can't get away from Airbus apparently). Nope, there is no system to confirm a leak apart from a camera around the tail if you're lucky enough to have one, my previous airline had a flight where an engine leak was detected this way. Think about it, how would you design such a system? So this falls on the crew. The procedure to determine if you have a leak is pretty much the same across ty…

Thank you for bringing your expertise here. I was wondering if you could give some insight on something that occurred to me while reading this: at first sight, transferring fuel to the leaking tanks might seem to be a substitute for the failure of the fuel jettison system, while also doing something about the increasing lateral imbalance.

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

#102

Post by MBCook »

resolutebat wrote: post #92
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?

High heels are not OK, for obvious reasons. Regular shoes are fine.

Huh. That sounded wrong so I googled it. I thought it was all shoes.

You’re right. What I said above used to be true. That seems to have been questioned in the 90s and in 2000 the FAA finalized a rule changing it.

The current recommendation (https://www.faa.gov/travelers/fly_safe/information) say you can keep your shoes on but to remove high heels, as you said.

A bit of googling says it was changed because of passengers injuring their feet on the terrain/debris after crashes. Additionally modern slides are much tougher than they used to be and won’t tear from shoes and probably even high heels.

But I bet high heels are probably not a smart thing to be wearing on possibly uneven debris covered terrain in an emergency when you need to move fast and safely.

Learn something new every day.

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

#103

Post by gumby »

resolutebat wrote: post #92
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?

High heels are not OK, for obvious reasons. Regular shoes are fine.

They confiscated all our shoes. Crashing into someone at the bottom with shoes could be a problem too.

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

#105

Post by stevepeg »

SkyPuncher wrote: post #78
stevepeg wrote: post #45

Earlier quoted context omitted.

A320/330/340/350 driver here (can't get away from Airbus apparently). Nope, there is no system to confirm a leak apart from a camera around the tail if you're lucky enough to have one, my previous airline had a flight where an engine leak was detected this way. Think about it, how would you design such a system? So this falls on the crew. The procedure to determine if you have a leak is pretty much the same across ty…

You could absolutely design a system that could detect a leak. I’m guessing that it’s just not common enough, or at least catastrophically common enough, to warrant. At its simplest you measure estimated volume delivered to the engines against estimated volume remaining in the tank. Both are things that should be digitally measurable. The problem seems to be that the only case it really matters is in a catastrophic a…

It’s a good idea, some aircraft have quite complex fuel systems though so it would have to account for fuel moving between tanks.

E.g. the A330 has an inner tank in each wing (which itself can be split into two compartments if damaged), an outer tank in each wing and fuel in the horizontal stabiliser which is used for CG control in the cruise. All of that plumbing can leak too. You’d be adding significant weight and complexity implementing leak detection across all that.

Regardless of all of this, the aircraft is still fully controllable even with a total asymmetry (one side empty the other full) so balancing the tanks isn’t a massive priority.

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

#106

Post by jshier »

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.

Yeah, according to the linked article 5 - 10% of people are injured using the escape slides, which is why they waited for the stairs in this case.

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

#107

Post by jshier »

sammy2255 wrote: post #100
rvnx wrote: post #89

Earlier quoted context omitted.

[flagged]

Are you seriously accusing Admiral Cloudberg of writing articles with ChatGPT?

It's an especially ironic accusation given she's currently dealing with YouTube channels stealing her write-ups and reading them into a video using AI. She even had a "if you read this you're an AI bot" section in an article a few weeks ago.

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

#108

Post by stevepeg »

mannykannot wrote: post #101
stevepeg wrote: post #45

Earlier quoted context omitted.

A320/330/340/350 driver here (can't get away from Airbus apparently). Nope, there is no system to confirm a leak apart from a camera around the tail if you're lucky enough to have one, my previous airline had a flight where an engine leak was detected this way. Think about it, how would you design such a system? So this falls on the crew. The procedure to determine if you have a leak is pretty much the same across ty…

Thank you for bringing your expertise here. I was wondering if you could give some insight on something that occurred to me while reading this: at first sight, transferring fuel to the leaking tanks might seem to be a substitute for the failure of the fuel jettison system, while also doing something about the increasing lateral imbalance.

That’s good lateral thinking :)

Given that the aircraft can be landed over max landing weight (needs a maintenance inspection) and is still controllable with total imbalance I’d say that balancing just wasn’t as pressing of a concern.

Also, with that much damage you never really know where else it could be leaking. Leaking fuel into critical spaces of the aircraft could be bad so turning on the fuel crossfeed might add extra issues.

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

#109

Post by mzi »

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.

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

#110

Post by tgbugs »

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.
Post reply on HN