[tooltalk]

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 with such obstructions in South Korea -- at Yeosu, it's 4 meters high (also concrete foundation)[1].

<strikethrough>There was a similar accident in Hiroshima, Japan several years ago: Airbus A320-200 skidded past the end of the runway at similar speed and struck down ILS. It eventually stopped -- damaged the airplane but no fatality.</strikethrough>

1. Localizer at Yeosu Airport, similar to Muan's, raises safety concerns, 2025.01.02 (23:58), KBS News.

[yongjik]

> There was a similar accident in Hiroshima, Japan several years ago: Airbus A320-200 skidded past the end of the runway at similar speed and struck down ILS. It eventually stopped -- damaged the airplane but no fatality.

Are you talking about Asiana Airlines 162? It hit localizer on its way to the runway because it came in too low. It then hit the runway, skidded on the runway, and stopped about halfway (after veering off the runway at the last moment).

If the same thing happened in Muan, the plane would have hit the localizer and then touched down, stopping in the runway. The fact that the localizer's base was concrete wouldn't have mattered because that's not where the plane would hit it.

[ricardobeat]

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.

[JohnKemeny]

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

[ricardobeat]

Technically correct yet missing the point. The plane could have disintegrated in a dozen other ways if the wall wasn’t there, or something else could be in the way.

I think the fact we have dramatic footage of the crash makes it a very attractive topic for engagement. News are spinning it into something it is not. A handful of massive errors happened and we know nothing yet, the focus on the structure for being in the way just makes for good clickbait, gives people an easy target to blame - the airport, engineers, regulators (doesn’t really matter who), and something to get riled up about.

[nialv7]

bad analogy. a better one would be: a wheel fell of an F1 car, car hit perimeter wall, driver dies. should we maybe put a crash barrier in front of the wall?

[ricardobeat]

This airport is basically already complying with the highest possible standard [1]; so in your analogy the crash barrier already exists, the equivalent argument would be for the track to have a 200m run-off area all around.

It's not feasible to plan for every possible freak occurrence, an accident like this is only possible after a long list of other safety procedures have failed (as is often the case for aviation).

[1] https://en.wikipedia.org/wiki/Runway_safety_area

[wlll]

Standards are the minimum, not the maximum.

Planes sometimes overshoot the runway, building an unecessary wall at the end of it might comply with a standard, but that doesn't make it a good idea.

[xmodem]

Perhaps the standard is flawed and needs to be updated.

[__m]

Not at all. Highest standard would have been a engineered materials arresting system, which the airport didn’t have.

[broeng]

Maybe that section of highway could easily be cleared in time with a warning system, like when we warn for crossing trains. A wall doesn't have to be the only solution.

[parasense]

I suppose we have to get into the engineering thought process of these Asian cultures.

Where did the idea of fortifying Localizer (LOC) come from, was there prior art specifying any degree of fortification (or lack) ? Perhaps these kind of radar (adjacent) installations are traditionally fortified, like maybe the civil air services were influenced from militry air services were things tend to be overengineered?

Perhaps saving the LOC is more important than saving a single aircraft? Some idea like this piece of infrastructure being more important that any single aircraft's safety?

The point is we might not see the reason why fortifying the LOC was obvious or straight forward to the Korean engineers.

Also, I've seen no credible evidence to support the idea the LOC is supposed to be built on a level surface, or built in a destructable way. Addressing the first point, the LOC makes sense to be slightly elevated given how they operate with near field low power radio waves. That said, these kind of slightly elevated instrument might not require an earthen mound, sourounded by concreate walls. Which goes to the second point, I can think of reasons to have these kind of LOC runways homing antenas destructable, and I can see them being robustly durrable. This thing was way past the end of the runway, and as unpo0pular as it might seems... it's a very bad thing to run out of runway. Somebody else wrote that some airports have a lack of open field beyond the end of the runway, and so it's a persuasive argument stuff could be built out there.

[dredmorbius]

You might find AA 1420 (1999) of interest, similar situation though far fewer fatalities (11 of 145 souls):

<https://en.wikipedia.org/wiki/American_Airlines_Flight_1420>

Partially-effective runway braking and a much greater distance from runway perimeter to the nonfrangible ILS structure likely played a role.

[inoffensivename]

Are you talking about Asiana 162? https://en.m.wikipedia.org/wiki/Asiana_Airlines_Flight_162

That one touched down short of the runway at a much lower speed and configured for landing.

[rmccue]

> The ILS are supposed to be built on level surface or "frangile" structure

Nit: I think the word you want is “frangible”, easy to break.