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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?

#101

Post by krisoft »

formerly_proven wrote: post #90
mmooss wrote: post #89

Earlier quoted context omitted.

> 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. (Assuming the math is correct:) That's the average speed over that distance. The plane would have been slowing down the whole time.

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).

> In the video it looked like the plane was only running on the rear landing gears,

Are we talking about the same crash? In the video I have seen[1] the plane appears to be on its belly dragging on the runway.

1: https://www.youtube.com/watch?v=qJY7oaZpxDU

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

#102

Post by formerly_proven »

krisoft wrote: post #101
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).

> In the video it looked like the plane was only running on the rear landing gears, Are we talking about the same crash? In the video I have seen[1] the plane appears to be on its belly dragging on the runway. 1: https://www.youtube.com/watch?v=qJY7oaZpxDU

True! I misremembered, in the longer video it's hard to see that the nacelles are dragging on the ground all the way. Still doesn't seem to slow down much.

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

#104

Post by drdrey »

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…

just because that aircraft was doomed (maybe?), that doesn't make it a good idea to have the concrete wall there

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

#105

Post by iso8859-1 »

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]

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

#106

Post by loeg »

earnestinger wrote: post #97
loeg wrote: post #82

Earlier quoted context omitted.

They declared mayday and then were on the ground in like 3 minutes. I think they probably just forgot gear given how rushed the landing was. We'll find out from the investigation.

Youtuber’s Denys Davydov (ex pilot of same plane), pet theory: bird got into the engine, pilot by mistake shut off wrong engine, due to no engine - hydraulic pump was non-functional, which resulted in landing gear problems. (also something about ground effect)

So... the degree of control they have over the plane on landing suggests they have some degree of hydraulic control. It's possible they throttled down the wrong engine, but this is speculation at this time.

Landing gear has a manual gravity release by the first officer that doesn't require the hydraulics. (But does take some time.)

Ground effect was certainly involved (why they glided so far before touching down) but the bigger factor was their high speed, lack of flaps, and lack of gear.

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

#107

Post by TylerE »

loeg wrote: post #80
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…

Maybe. But maybe another 1000m of dirt would have been enough to slow them before the treeline. The area south of the runway is mostly an easement for the ILS approach equipment, then a parking lot and finally some trees. It's also definitely the case that the cement-reinforced dirt mound is not best practice for a locator array.

Yes, but in basically every single circumstance if you have room for 1000m of dirt, you have room for another 1000m of runway, which is even safer.

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

#108

Post by ynniv »

blitzar wrote: post #103
baq wrote: post #29

The title question is like the 20th in order of importance why this crash happened…

Cause of death was impacting a concrete barrier.

Cause of death was landing halfway down a runway at high speed with no gear. Why were they cleared to land if they hadn't set flaps and locked gear? There was ocean in front of them both before and after their turn: landing there would have been more survivable than landing fast and hard with no gear. They were below minimum turnback altitude, and wouldn't have been able to complete the planned turn without the same power that could have been used to stay aloft and sort out their problems.

Nothing about this crash was normal, and talking about a thing past the end of the runway is misdirection.

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

#109

Post by frosting1337 »

iso8859-1 wrote: post #105
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]

> Tell her she is wrong. It's an international airport with commercial traffic. 11th most busiest airport in the country.

It's... a tiny airport, both by commercial standards and by South Korean standards.

Pretty sure you're just trolling though, no way this is a serious comment.

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

#110

Post by neom »

iso8859-1 wrote: post #105
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]

"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 misunderstood the question.
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