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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?

#81

Post by loeg »

rich_sasha wrote: post #68
ra wrote: post #23

Earlier quoted context omitted.

That's not correct. A runway can be used in either direction, if you look on Google maps you can see the runway at Jeju has markings at both ends including a number (denoting it's compass heading) - both ends are usable. You always want to land with a headwind and never a tailwind, so ATC will use whichever end is favorable for the current conditions. In this case, if they attempted to land with a tailwind then the o…

I read that the opposite direction had a NOTAM exclusion, i.e. was excluded from use. From the professional pilot forum linked a few days ago in a similar thread. If that's right then OP would be correct in saying, this direction wasn't meant to be used.

Ok but in an emergency all bets are off, the opposite direction is better than a crash landing. So you can't just assume 100% of landings are in one direction.

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

#82

Post by loeg »

K0balt wrote: post #39
gazchop wrote: post #13

Earlier quoted context omitted.

They already botched a gear down landing, which is almost never mentioned. They retracted the gear and did a teardrop go around from a headwind into a tailwind belly flop. Stinks of bad crew resource management and ATC which is why the ATC and airline for raided by SK officials.

We don’t know why the pilot elected to double back instead of go around. There may have been indications of a progressive failure that indicated that course of action, but it does seem hasty. That haste may have caused them to not be able to set up a stabilized, minimum speed approach, and may have contributed to the long touchdown, which certainly was a contributing factor. If there were significant winds it would h…

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.

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

#83

Post by loeg »

tedunangst wrote: post #19

How much difference would an additional 50m have made?

They'd probably have another 1000m of relatively clear ground without the localizer mound. The brick fence probably wouldn't significantly slow the aircraft, then you have a relatively clear easement (with ILS approach towers, hopefully frangible) until a parking lot and trees on the south coast.

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

#84

Post by loeg »

EliRivers wrote: post #54
baq wrote: post #36

Earlier quoted context omitted.

To be brutally honest, the plane would crash about a second later, so approximately none whatsoever. But this isn’t the right question to ask, as it isn’t the right question to ask why the wall was there. Why did the pilot and ATC decide it’s a good idea to attempt a gear up landing in the wrong direction is a good start.

I recall back in 2020, when Pakistan International flight 8303 belly landed at Karachi, slid down the runway, and then took off again and had a go at going around, the investigation showed that between them, the pilots just screwed up on having the landing gear down and had a go at landing without it for no other reason than they fumbled it.

The PIA pilots totally fucked up the approach, missed that they were very high late in the approach, dive bombed down to the runway at the last minute instead of going around. CRM issues -- the senior pilot plausibly couldn't actually fly (he had a history of bad approaches with unsafe descents) and the first officer failed to raise major problems or push back at all on unsafe decisions. When they first touched down gear up, they had dual stick inputs (one pilot was pushing down, one was pulling up) -- this is a huge no no. Communication in the cockpit was awful. Just lots of awful.

After the incident, PIA pilots were audited and determined like 1/3 had fake or suspicious pilot licenses(!!!). Lots of paying other people to pass tests for you. Internationally, PIA has been banned from landing by like all first world countries.

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

#85

Post by robinson-wall »

underseacables wrote: post #74
f1shy wrote: post #72

Earlier quoted context omitted.

There are 3 different hydraulic system plus one electric that can be operated out of a battery… anything is possible, but it seems until now they failed to lower the gear.

Something else that may be a factor, a lot of Asian carriers teach their pilots to use auto pilot for landing. American pilots almost universally SOP do not use auto pilot when landing. It's possible the South Korean pilot was using auto pilot to land, forced to do a go around, but wasn't in the habit of manually configuring the plane for landing. That's how the flaps and the gear were both missed. He assumed autopil…

Which aircraft have flaps or gear controlled by an autopilot? I'm just an armchair "Air Crash Investigations" fan, but I've never heard of any aircraft where either flaps and gear would be automatically controlled by their autopilot. Speedbreaks / spoilers are usually armed and moved automatically on landing.

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

#86

Post by loeg »

f1shy wrote: post #72
K0balt wrote: post #45

Earlier quoted context omitted.

When an engine blows up, it’s hard to say what still worked and what didn’t. They aren’t supposed to, but when turbines come apart, there is often a lot of shrapnel that has a history of taking out multiple systems. But, it is possible that it was a case of poor crew performance. In any case, the concrete blockhouse at the end of the runway was unhelpful, and it is also outside of the standard guidance for runway ali…

There are 3 different hydraulic system plus one electric that can be operated out of a battery… anything is possible, but it seems until now they failed to lower the gear.

There's also a backup manual gear release. But from the degree of control over the airplane demonstrated during landing, it seems likely they had hydraulics.

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

#87

Post by kiririn »

underseacables wrote: post #33
hilux wrote: post #2

So many things went wrong, and yet the pilots brought the plane down safely – and then this!? Just infuriating.

They did not bring the plane down safely! The pilot failed to lower the landing gear, or extend the flaps, both of which, for all intensive purposes were technologically possible. Multiple redundant systems for these. I think they completely lost situational awareness, and panicked.

>for all intensive purposes

Always a funny one, it's for all intents and purposes

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

#88

Post by rogerrogerr »

lutusp wrote: post #60
ge96 wrote: post #37

I was wondering what if they tried to turn whether by rudder or thrust differential would the outcome have been different/worse. Maybe you can't do much at that speed and so little room.

I'm a pilot. The airplane was sliding on the ground and the landing gear was not deployed. Too fast to stop but not fast enough to use the rudder for directional control. There was no realistic chance to change direction. If there had been enough engine power to control direction on the ground, there might also have been enough power to remain airborne, but based on limited information, that wasn't so. Under the circ…

> not fast enough to use the rudder for directional control.

Sure about that? 160kt (how fast someone calculated it went off the end of the runway) is way above Vs1 for a 737, there should be plenty of rudder authority. Heck, Vapp is usually in the 130-150kt range.

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

#89

Post by mmooss »

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…

> 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.

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

#90

Post by formerly_proven »

mmooss wrote: post #89
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…

> 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).

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