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Why was there a wall near runway at S Korea plane crash airport?

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Re: Why was there a wall near runway at S Korea plane crash airport?

#351

Post by iso8859-1 »

neom wrote: post #110
iso8859-1 wrote: post #105

Earlier quoted context omitted.

[flagged]

"One strategy I use for my relationships with foreigners is to gently pat them on their heads if they understand me. That way, there is positive reinforcement and they are encouraged to improve their understanding." - this may very well be one of the most condescending and disrespectful things I've read on hackernews ever. Also, my wife has a PhD in American History from Yale and teaches at SUNY, I don't suspect she…

You're assessment is correct and it was indecent of me to say such things. I'd like to apologize for both the condescension and the lack of respect.

Re: Why was there a wall near runway at S Korea plane crash airport?

#352

Post by neom »

iso8859-1 wrote: post #351
neom wrote: post #110

Earlier quoted context omitted.

"One strategy I use for my relationships with foreigners is to gently pat them on their heads if they understand me. That way, there is positive reinforcement and they are encouraged to improve their understanding." - this may very well be one of the most condescending and disrespectful things I've read on hackernews ever. Also, my wife has a PhD in American History from Yale and teaches at SUNY, I don't suspect she…

You're assessment is correct and it was indecent of me to say such things. I'd like to apologize for both the condescension and the lack of respect.

We'll consider the matter settled then. I genuinely appreciate the apologies. Have a happy new year.

Re: Why was there a wall near runway at S Korea plane crash airport?

#353

Post by dredmorbius »

m463 wrote: post #328
alkonaut wrote: post #301

Earlier quoted context omitted.

If it’s possible in any way to keep the next few km after a runway clear, then it should be clear. Ocean is great. Empty fields are great. If you are lucky enough to have empty fields but put a concrete wall there, then that’s almost malicious. The cause of any fatality in aviation is never a single thing. It’s invariably a chain of events where removing any one thing in the chain would prevent the disaster.

The wall might critical to keeping things off the runway, like animals and people.

This one isn't. It's a relatively short support structure, not a battlement.

There are cinderblock a cinderblock wall and numerous chin-link (and razor-wire-topped) fences in the area, which do control airport access. Those would likely not have proved fatal to the aircraft to any similar extent however.

Re: Why was there a wall near runway at S Korea plane crash airport?

#354

Post by dredmorbius »

bagels wrote: post #287
dredmorbius wrote: post #267

Earlier quoted context omitted.

It's a vastly more challenging goal, with higher engineering, financial, and land-use requirements. Passenger survivial: Decelleration g-forces kept within a given threshold, evacuation slides operable, passengers cleared within 90 seconds. Hull is sacrificed. Airframe survival: No significant damage to aircraft structure or systems. Humans in this case are substantially more robust than aircraft. You'll find a simil…

When the wings come off, you get a pretty big fire though. Obviously they cannot be made infinitely strong, but I'd rather be in the plane that isn't disintegrating and in fire.

Armouring wings against fuel-system penetration (tanks, hoses, valves, etc.) in a mishap is an absolutely insane level of engineering, and all but certainly infeasible.

The much more reasonable alternative is to have 1) fuel-dumping systems which rid the craft of excess fuel prior to an emergency landing (another reason, BTW, to remain aloft as long as possible after an emergency has been declared), and 2) to have the means to evacuate the aircraft quickly. Modern standard is 90 seconds, with only half the exits in use. Initial fireballs, whilst impressive, usually occur largely above the aircraft and direct heat upwards. It's the subsequent ground- and cabin-based fires which are most lethal, and those tend not to develop for about two minutes.

https://simpleflying.com/aircraft-90-second-evacuation/>

After that, you want the actual fuselage and passenger restraint systems (seats, seat belts) to provide maximum protection against injury in the crash itself. They largely do this. At least when aircraft aren't encountering Muan Murder Walls at speeds well in excess of 100 kt and disintegrating fully.

Re: Why was there a wall near runway at S Korea plane crash airport?

#355

Post by dredmorbius »

YeGoblynQueenne wrote: post #331
SoftTalker wrote: post #254

Earlier quoted context omitted.

The plane was sliding on its belly, wheels up. It wasn't slowing down very much. Ever play on a slip-n-slide as a kid?

Can't speak about the OP but I didn't weigh a few thousand metric tons as a kid. Or as an adult. I am on a diet though.

Set yourself a goal!

And good news! A fully-loaded 737-800 has a maximum takeoff weight of less than 80 tonnes, not thousands, so your challenge is much more attainable!

https://en.wikipedia.org/wiki/Boeing_737_Next_Generation#Spe...>

Re: Why was there a wall near runway at S Korea plane crash airport?

#356

Post by dang »

carabiner wrote: post #278
neom wrote: post #99

My wife is South Korean (from andong). I asked her and she looked at me like I'd grown a second head "because it's South Korea? We're a young country and that is tiny airport in the south, half of Korea is a safety hazard and you know that fine well, some freaking idiot put a wall there, oh well, it's korea" and walked off pretty angry I'd even asked.

[flagged]

Personal attacks will get you banned here—and this was a shameful one. No more of this, please.

Edit: we've had to ask you many times to stop breaking the site guidelines:

https://news.ycombinator.com/item?id=38198402 (Nov 2023)

https://news.ycombinator.com/item?id=37367901 (Sept 2023)

https://news.ycombinator.com/item?id=36896498 (July 2023)

https://news.ycombinator.com/item?id=35759087 (April 2023)

https://news.ycombinator.com/item?id=34698866 (Feb 2023)

https://news.ycombinator.com/item?id=25128446 (Nov 2020)

Eventually we have to ban accounts that keep doing this, so please stop.

Re: Why was there a wall near runway at S Korea plane crash airport?

#357

Post by cameronh90 »

ak217 wrote: post #265
cameronh90 wrote: post #156

Earlier quoted context omitted.

The obstacle obviously didn't cause the crash, but it's still probable that fewer people would have died if it wasn't there, and it seems to have been put there for no valid reason, quite recently, and against standard practice. Along with the reports that their bird control devices had not been implemented and that only 1 of the required 4 staff to repel birds were on duty. All these factors together may suggest an…

I don't know why the pilots landed the way they did but the structure was there for a valid reason. It's the runway localizer antenna. It was elevated off the ground to protect it from flooding. Should it have been frangible, yes, but it's not at all out of the ordinary as far as structures near runways go, and I think the focus on it is sensationalist and misguided.

By structure I meant the dirt mound with a concrete wall inside it, not the localizer. Entirely normal to have a localizer, but usually on a frangible structure if it needs to be elevated.

Re: Why was there a wall near runway at S Korea plane crash airport?

#358

Post by dredmorbius »

blueflow wrote: post #307
dredmorbius wrote: post #237

Earlier quoted context omitted.

History says otherwise. Most runway overruns occur with no or few fatalities: https://news.ycombinator.com/item?id=42606790 >

Yes, because the speed was lower. Kinetic energy increases with speed squared. Uncontrolled 300 km/h on the ground kills you in any vehicle.

That's a fair argument, and I've noted the kinetic energy aspect elsewhere in this discussion.

That said, based on my observations of the terrain past the runway / airport threshold, it seems to me that absent the Muan Murder Wall, survivability would have been far higher in this case. See: https://news.ycombinator.com/item?id=42607464>

I've yet to find a source that does a better job of organising incidents by landing speed / profile in a way which might better provide for more direct comparisons.

Re: Why was there a wall near runway at S Korea plane crash airport?

#359

Post by YeGoblynQueenne »

dredmorbius wrote: post #355
YeGoblynQueenne wrote: post #331

Earlier quoted context omitted.

Can't speak about the OP but I didn't weigh a few thousand metric tons as a kid. Or as an adult. I am on a diet though.

Set yourself a goal! And good news! A fully-loaded 737-800 has a maximum takeoff weight of less than 80 tonnes, not thousands, so your challenge is much more attainable! https://en.wikipedia.org/wiki/Boeing_737_Next_Generation#Spe... >

Yeah I always overestimate those things by far :)

Re: Why was there a wall near runway at S Korea plane crash airport?

#360

Post by LtWorf »

lolc wrote: post #344
LtWorf wrote: post #343

Earlier quoted context omitted.

Even if they lock completely, they'll skid more than the entire hull's skidding no?

The trick is not to lock and use static friction. https://en.m.wikipedia.org/wiki/Stiction Hm, the stiction page on Wikipedia does not explain how it relates to braking. Maybe check out https://en.m.wikipedia.org/wiki/Threshold_braking

Thanks for the link. Nowhere it seems to indicate that the friction of the breaking would be greater than the friction of the hull, since the pages related to non-destructive braking.
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