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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?

#311
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 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.

Agreed. I work on a different type of vehicle with safety-critical systems for a living, and I'm naturally also very interested in the interactions between the pilots and the machine (and among themselves) and the spiral of events in the cockpit.

But that doesn't mean debating whether there's a better way to engineer typhoon-resilient localizer antenna arrays isn't also a good use of time. Safety makes it imperative to discuss all of these matters exhaustively.

Re ocean, no, that isn't so great - sea rescue is a lot more difficult to perform than on land.

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

#312
post #311

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.

Agreed. I work on a different type of vehicle with safety-critical systems for a living, and I'm naturally also very interested in the interactions between the pilots and the machine (and among themselves) and the spiral of events in the cockpit. But that doesn't mean debating whether there's a better way to engineer typhoon-resilient localizer antenna arrays isn't also a good use of time. Safety makes it imperative…

Sure but if you have 3km of open water following the runway then don’t block it with a concrete wall (even if that wall prevents storm flooding 2 days every 5 years). Sea rescue is a lot easier than rescuing people who drove into a concrete wall.

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

#313
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.

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…

> 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.

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

#314
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 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.

> If you are lucky enough to have empty fields but put a concrete wall there ...

I am fairly sure this will be one of the findings of the investigation. I hazard a guess that every sane operator of an airport in the world is walking from the end of their runway to the airfield perimeter and taking a look anyway.

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

#316
post #171
post #51

Earlier quoted context omitted.

They retracted the gear after the first landing attempt. I suspect they either missed it on the teardrop or had secondary hydraulic failure and no time to do a gravity drop. I would err on the side of crew error because there were clear signs the hydraulic systems were functioning (thrust reverser and that they could retract the gear in the first place). Hydraulics don’t fail instantly and one engine was spooling sti…

I've seen reports they had gear down in the first approach and also that they didn't. Is there anything conclusive yet?

Yes, if you view the footage of the bird strike on first approach you will see the landing gear is extended.

ETA: The primary footage is hard to find now that the topic is so saturated, but there is a specific clip from a close vantage where it is highly visible. I'll include a link if I can find it.

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

#317
> Firefighters said some bodies were scattered 100 to 200 m (330 to 660 ft) from the crash site while others were found mutilated or burnt among the wreckage.[61] Police officials said it would require over a week to identify the more than 600 human remains recovered.[62] Some family members provided officials with DNA samples at the airport to help identify the dead.[4] (Wikipedia)

Does this mean the crash was so violent that the 179 bodies disintegrated into more than 600 parts?

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

#318

> Firefighters said some bodies were scattered 100 to 200 m (330 to 660 ft) from the crash site while others were found mutilated or burnt among the wreckage.[61] Police officials said it would require over a week to identify the more than 600 human remains recovered.[62] Some family members provided officials with DNA samples at the airport to help identify the dead.[4] (Wikipedia) Does this mean the crash was so vi…

The plane hit a concrete wall at something like 150 knots, so it was pretty violent.

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

#319
post #290

Earlier quoted context omitted.

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?

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).…

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.

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

#320
post #309

Earlier quoted context omitted.

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).…

Perhaps the standard is flawed and needs to be updated.

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