Korean airline emergency landing goes wrong and many killed

It did look like a late touchdown, but what the reason was?

Huh, just went back to watch the video in my post#3, and how about that? The URL has had the video changed so that it no longer shows the actual crash, now it only shows the flaming and smoking wreckage over & over again.

There's rumours this same aircraft squaked 7700 with a hydraulics issue a few days prior to this.

The mound at the end of the runaway has a big role to play too.

The only issue with a Total Hydraulic failure is that Modern Airliners have at least 2 and usually 3 separate Hydraulic systems, with engine driven Pumps on each engine, and a electric hydraulic pump, and usually a reversible hydraulic pump motor assembly, not to mention the RAT or Ram Air Turbine that can provide a minimum hydraulic and electrical power for emergency use. The only realistic way you can have a total loss of hydraulic power is to lose all of the fluid, and as there are no common lines shared between the systems, and they all have separate reservoirs. It would take a case like the United Airlines Sioux City Iowa crash where the #2 engine fan assembly came off and cut thru all 3 systems lines in the horizontal stabilizer where they are in close proximity on the DC-10. And even then it took over 30 minutes for enough fluid to leak out to make the A/C uncontrollable.

Granted something catastrophic happened, but I do not think it was a total hydraulic system failure. But we will see what the investigation uncovers. But I suspect it will not be this week that we get an answer.

fubar57 said:

CBC just reported about a wall that should not have been at the end of the runway. This area is supposed to be free of obstacles to allow for overshooting. The "expert" on CBC said, had this wall not been there, no explosion

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The embankment is 250 meters or 800 feet from the end of the runway. That is a long way from the end of the runway.

The fact that the aircraft was going 150 mph when it hit that embankment is not the fault of the design of the airport.

Aircraft aren't supposed to be going 150 mph on the ground 800 feet from the end of the runway.

Here's the runway if anyone is interested, dated Sept. '24

I just remembered an odd incident from my airline days that could also lead to a full hydraulic failure, but I don't think it would be a factor in this crash.

At one of our smaller out stations that at the time only smaller DC-9's and Convair 580's flew into. Someone contaminated the Hydraulic refilling bowser with hand soap of all things. Apparently the station had 55 gallon drums of both Skydrol hydraulic fluid and the hand soap side by side and as both fluids have a purple color to them they got confused.

The Convair's were not affected as they still used 5606 Hydraulic fluid that is dyed red. The 5 or so DC-9's that were affected were having odd hydraulic issues, and more frequent failures of the seals on hydraulic actuators. The actual biggest complaint by the flight crews was inconsistent braking, and nose gear shimmy at high taxi speeds. We had replaced the shimmy dampers and bled the brakes many times. The actual brakes had also been replaced, and the write ups continued.

The problem was finally discovered several weeks later when one of the A/C developed a pin hole leak in one of the hydraulic lines in the right wheel well. A pin hole in a line under pressure usually results in a fine mist spraying out of the hole. In this case besides the fine mist it looked like a bubble machine was operating in the right wheel well! With purple bubbles coming out of the wheel well with the main gear door opened!

Well we had to conduct fluid sampling of the entire fleet's hydraulic systems after that. And we did find that it was contained to about 5 of the smaller DC-9-10 & DC-9-30 models. All the affected A/C were taken out of service, had there Hydraulic systems drained and flushed. I am not sure what if any of the hydraulic components were changed as most of the work was done at the main Maintenance base. We only performed the work on the 1st DC-9 that the issues was discovered on.

So Hydraulic fluid contamination is also a remote possibility. But I still think that it was not a hydraulic issue as the aircraft looked to still be controllable and was wings level and headed down the runway at the time of the accident. If there was a big issue with the hydraulic systems it would have affected the abilities of the crew to steer the aircraft.

That being said I should also state that I do not have any experience with 737's other than a few small servicing items on older 727-200 & 300 models. And the most modern Boeing products I have worked on are 757 & 747-400 models.

ThomasP said:

It did look like a late touchdown, but what the reason was?

Huh, just went back to watch the video in my post#3, and how about that? The URL has had the video changed so that it no longer shows the actual crash, now it only shows the flaming and smoking wreckage over & over again.

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Video here....for now. Scroll down a wee bit..... World News | International Headlines - Breaking World News

Still watching this video, and I'm unqualified to comment anyway, but --


View: https://www.youtube.com/watch?v=8OflieROU

Nothing like a raid by people who do not know what they are looking at to destroy the evidence that the experts will need when they try to do things slowly and methodically.

Without gear down, no wheel braking, and appears to be neither flaps or spoilers for aero braking, which would have likely forced nose down. Appears to be very long in touchdown, metal on concrete is low friction, and nose high attitude seems strange.
Few reports have mentioned there was a very effective plowed gravel area at runway end, but that would work only with gear down, nose down.
Until NTSB, etc. we're armchair experts, but seems like a lot of bad decisions, system failures, and short runway working together.

Just to add to the speculation on this indecent, I just watched a news video of the recovery of the engines, and the fan blades of the #2 engine (Rt side) show extensive damage that indicate it was running at the time of the impact with the earthen wall, the #1 engine fan blades only seem to be slightly damaged, they are packed with dirt, but to my eyes it would indicate the #1 engine was not running at the time of the impact.
The Video's of the crash seem to show the #2 engine ingest birds, and compressor stall, I have not seen any video evidence of the #1 engine ingesting birds, or experiencing a compressor stall. But that does not mean it did not happen. I also wont speculate on if the crew shut down the wrong engine, it has happened before, and probably will again. We all make mistakes.
The news cast also said the information from the flight data recorder and voice record was expected to be delivered to the South Korean authorities some time today.

cammerjeff said:

Just to add to the speculation on this indecent, I just watched a news video of the recovery of the engines, and the fan blades of the #2 engine (Rt side) show extensive damage that indicate it was running at the time of the impact with the earthen wall, the #1 engine fan blades only seem to be slightly damaged, they are packed with dirt, but to my eyes it would indicate the #1 engine was not running at the time of the impact.
The Video's of the crash seem to show the #2 engine ingest birds, and compressor stall, I have not seen any video evidence of the #1 engine ingesting birds, or experiencing a compressor stall. But that does not mean it did not happen. I also wont speculate on if the crew shut down the wrong engine, it has happened before, and probably will again. We all make mistakes.
The news cast also said the information from the flight data recorder and voice record was expected to be delivered to the South Korean authorities some time today.

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Remember that the video showing the #2 bird strike was taken by a phone camera and depending on how the phone was held by the owner that CAN produce picture reversal - meaning that may actually be a showing #1 engine bird strike.

SEOUL, South Korea (AP) — The black boxes of a Boeing jetliner that crashed in South Korea last month stopped recording about four minutes before the accident, South Korean officials said Saturday, possibly complicating investigations into the cause of the disaster that killed 179 people.

After analyzing the devices, the U.S. National Transportation Safety Board concluded that both the flight data and cockpit voice recorders stopped working about four minutes before the crash, the South Korean Transportation Ministry said.

The Boeing 737-800 operated by Jeju Air skidded off a runway in the South Korean town of Muan on Dec. 29 after its landing gear failed to deploy, slamming into a concrete structure and bursting into flames, killing all but two of the 181 people on board.

That's interesting, I can't remember how the electrical shed buses work on Boeing products, but that makes me think they lost the electrical power from both engines, did not have the APU running, and the flight controls and radio's were being run off the aircraft batteries. I don't have access to the electrical schematic's for any 737 models. But it is possible the electrical systems shed busses may have turned off the power to the Black boxes to preserve power for the aircraft control systems.

But that is just speculation on my part. I know that on non fly by wire aircraft they would not shed the power from the black boxes, I can't remember what the Airbus A320 or A330 models do in that situation. I may still have manuals on those models in the basement. Now I may have to look for them.

I am fairly sure that the recorders are not only on the essential buss but cannot be turned off by the crew so this indicates something serious was happening. It suggests the decision to belly land immediately was probably forced on the crew.

What are the chances that a bird strike could compromise the primary power system, though?

Could there have been an external impact that may have led the pilot think that it was a bird strike?

Only time will tell. A single engine failure should not take out anything essential. And there is no indication of an un-contained engine failure which could have caused secondary damage so all we can do is wait for the NTSB and Koreans to provide reports

IIRC The black boxes have their own independent power supply (ie onboard batteries whose sole purpose are to power the recording devices and the location transponders), but if the devices that send the information to the black boxes stopped sending at 4 minutes before the crash then saying that the black boxes stopped recording might be an imprecise way of saying what happened - ie the sending devices stopped sending so there was no incoming data for the black boxes to record. Maybe?