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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?

#291

Post by ricardobeat »

Xixi wrote: post #263
pixelesque wrote: post #250

Earlier quoted context omitted.

Firstly, this airport has only been taking international flights since the early December. There was also construction work going on at one end of the runway (until March), and the threshold was pushed back 300 metres, shortening the runway by that much: http://aim.koca.go.kr/eaipPub/Package/2024-10-31-AIRAC/html/... The runway also is not flat (which is why the localiser beams at that end need to be raised in the fi…

Very good point regarding international flights. Of course, I'm making the assumption that the pilots somehow had to attempt a "a very fast landing, with no gear or flaps, spoilers". The core of the issue is probably there, hopefully the investigation will yield useful results. But what I am fundamentally questioning is whether the pilots would have attempted that landing if they had been expecting a piece of reinfor…

In most airports you can expect highways, buildings, water and other structures after the runoff area.

The airport where it happened doesn’t appear to have any less clearance than usual around the runway [1], if not more when comparing to Jeju Airport for example [2].

[1] https://maps.apple.com/?ll=34.976342,126.382712&q=Marked%20L...

[2] https://maps.apple.com/?ll=33.515456,126.498733&q=Marked%20L...

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

#292

Post by YuukiRey »

reso wrote: post #149

The wall is a red herring. The plane landed halfway down the runway at high speed. Something bad is going to happen if you do that at any runway on earth. In SFO you'll end up in the bay or hit the terminal depending on the orientation. In Toronto you'll crash into a highway. Stop looking at the wall and look at the minutes before the crash.

If you can get the same features with less risk it seems like a worthwhile thing to consider.

Meaning if we can build the same antenna array but with less risk to airplanes and all at an acceptable economical cost, it feels like something we should do. Regardless of whether or not a runway overrun at other airports and in other situations poses more or less risk.

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

#293

Post by 3ple_alpha »

dgfitz wrote: post #132
formerly_proven wrote: post #90

Earlier quoted context omitted.

I'm not a pilot. In the video it looked like the plane was only running on the rear landing gears, I assume with no brakes applied, since that would've caused it to violently pitch down I assume. Only in the last bit did it pitch down and started scraping along the runway. It certainly doesn't look like it was efficiently shedding speed (but looks can be deceiving).

I have been under the distinct impression for a long time that a plane slowing on the runway has very little to do with landing gear brakes.

If one divides weight of the airplane by the number of wheels it has, one would find one wheel carries around 10 times more weight than that of a truck. You even get a slightly better deal on landing when you don't have as much fuel.

That's a lot of weight but nothing crazy, so on a dry runway wheel brakes alone are more than enough to stop normally. They would also wear out a lot, overheat and occasionally ignite if used like that, so that's what thrust reversers are for.

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

#294

Post by neom »

user_7832 wrote: post #286
neom wrote: post #256

Earlier quoted context omitted.

They executed a pretty difficult turn, apparently it's called the impossible tear drop and you're trained specifically NOT to ever do it. I looked at the flight tracking, I suspect the maneuver they pulled just put them at that point in the runway[1]. If you read my reply to the comment above you, it has some additional context you might find interesting. They pilots I watched all mentioned really, it doesn't make se…

> it's called the impossible tear drop Minor nit, I believe it’s called the teardrop go around for such cases. You also have the impossible turn which is meant typically for engine/power failure during takeoff, and it actually is possible to be safely done - as demonstrated by the former ALPA Air Safety Institute Senior VP Richard McSpadden in one of his YouTube videos. However, it can be deceptively difficult to hav…

Thank you for the clarification, I hoped I couched everything enough people knew I'm just reading internet and not at all an expert, I appreciate the reply!

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

#295

Post by [deleted] »

MoreMoore wrote: post #164
blueflow wrote: post #77

I'll recite an avherald comment: If you look at "Video of aircraft after touchdown sliding along the runway and impacting the fence:", you will find out that it took them ~1.7 sec from leaving the tarmac until they hit the construction. If you measure the distance on Google earth you come up with ~140m. That means they hit the construction with roughly 296km/h or 160 knots. If it wasn't the construction it would have…

So you'd rather them have a certain 100% chance of death instead of more leeway and a chance against much less robust trees? Honestly, if I crash land, I think I prefer 150 more meters and a tree as the obstacle over the concrete block. What is going on here and what's with this crazy ass logic?

[deleted]

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

#296

Post by [deleted] »

chii wrote: post #247
reso wrote: post #244

Earlier quoted context omitted.

You're making an assumption that the outcome would have been different if that wall wasn't there. You're wrong. 50m past that wall is another wall, 5m after that is a highway.

the 2nd wall is a brick wall, rather than reinforced concrete (which is what seems to be the first wall). I dont think the plane would get pulverized hitting a brick wall, and the distance will also slow the speed. And the highway is not above the plane's travel axis, so the highway is a non sequitur. Not to mention even more distance to slow down.

[deleted]

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

#297

Post by nhinck3 »

dredmorbius wrote: post #237
reisse wrote: post #203

Earlier quoted context omitted.

No amount of ample room will help if the plane touches down overshooting more than half of the runway. Furthermore (this is pure speculation at the moment) I think chances are the crew were kind of cosplaying PIA PK-8303 - forgot about landing gears in a stress from bird strike, attempted go-around after realising it, but had not enough power from engines due to bird strike or ground hit. It's plausible final investi…

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

I looked into all of those and of the ones that had speeds available, they were half or less than half the speed at the time of overrun

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

#298

Post by throwaway290 »

> At a news conference on Tuesday, Jeju Air's chief executive Kim Yi-bae would not be drawn when asked about the concrete wall.

I don't understand what means "would not be drawn"?

> Asked by a reporter if he thought the wall was a factor in the disaster, he did not give a direct answer and instead said it was right to call the plane crash the Jeju Air disaster, rather than the Muan Air disaster.

If I get this right, I think this CEO deserves props for not trying to point blame away. Let's see what investigation shows.

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

#299

Post by JohnKemeny »

ricardobeat wrote: post #289
tooltalk wrote: post #184

Earlier quoted context omitted.

Occam's razor: the wall is most probably the cause of the unnecessary explosion that killed 179 people. The airport built ILS, or localizer, on unnecessarily over-engineered concrete structure where there shouldn't have been any obstruction. The ILS are supposed to be built on level surface or "frangile" structure so they can be easily destroyed when there is an overrun. There are reportedly at least 4 other airports…

If the wheels drop off my car at 100km/h and I lose control and hit a wall, is the wall the cause of the accident? The barrier was 250m away from the end of the runway, the extra 50m if following regulations wouldn’t have changed the outcome. And if the wall wasn’t there, the plane would dive right into a highway anyway. That’s the point.

The wall is clearly not the cause of your accident, but might nevertheless be the cause of your death.

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

#300

Post by blueflow »

MoreMoore wrote: post #164
blueflow wrote: post #77

I'll recite an avherald comment: If you look at "Video of aircraft after touchdown sliding along the runway and impacting the fence:", you will find out that it took them ~1.7 sec from leaving the tarmac until they hit the construction. If you measure the distance on Google earth you come up with ~140m. That means they hit the construction with roughly 296km/h or 160 knots. If it wasn't the construction it would have…

So you'd rather them have a certain 100% chance of death instead of more leeway and a chance against much less robust trees? Honestly, if I crash land, I think I prefer 150 more meters and a tree as the obstacle over the concrete block. What is going on here and what's with this crazy ass logic?

Do you believe the plane would have stayed in one piece if it wasn't for obstacles?
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