Muan Airport plane crash, most passengers presumed dead

■ Host: Anchor Moon Sung-gyu and Anchor Park Se-mi
■ Starring: Lee Young-joo, Professor of Fire and Disaster Prevention at Kyungil University

* The text below may differ from the actual broadcast content, so please check the broadcast for more accurate information. Please specify [YTN News Special] when quoting.

[Anchor]
This time, we will continue to bring experts and update you on the aircraft accident. Lee Young-joo, a professor of fire and disaster prevention at Kyungil University, is here. Please come in. We're talking with various experts today to understand the cause of the accident and we're talking like that. Unfortunately, it is now understood that all but two rescuers have died. Why was this accident so victimized?

[Lee Young-joo]
Aircraft accidents. If we look at previous accidents in other countries and in Korea through reports, aircraft accidents do not occur frequently, but they are accidents that cause a lot of casualties once they occur, so those characteristics are also a basic premise. However, in the case of this accident, such as a fuselage landing, the process of attempting an abnormal landing without properly unfolding the landing gear, and these slide off the runway and collide with the wall, leading to a fire explosion. Therefore, it was a dangerous situation where the situation had already been completed before the actual passengers and these people were evacuated or rescued, leading to a sad accident in which many lives were lost and almost all but two people died.

[Anchor]
I sent it to you earlier as a report. There was a shooting down of Korean Air in 1983 and a crash in Guam in 1997, and there were also many victims. The Asiana Airlines plane accident at San Francisco Airport in 2013 killed three people. But there were also a lot of people who were hurt. There were about 180 people, and even then, the fuselage was quite damaged.

[Lee Young-joo]
That's right. At that time, the fuselage was damaged a lot, but it didn't lead to a fire explosion right away, so the process of quickly evacuating or rescuing people from emergency situations after the fuselage landed, so this was a possibility that could reduce deaths even more. In the case of this accident, there is a difference in the situation where there is not a stop due to landing, but a situation where the people in it were not able to do something, and in fact, there was no opportunity to rescue or evacuate themselves by directly leading to a collision and an explosion in the situation where they slipped. Let's look at it like this.

[Anchor]
It happened during the landing process of this accident. The plane, which was landing at a great speed, crashed into the outer wall. What is the normal speed of running on the runway when a plane lands?

[Lee Young-joo]
Basically, in the case of medium-sized planes, this plane performs considerable deceleration when landing on the runway. So, the landing is carried out with the speed of about 130km to 140km to reach the ground of the runway, and after that, various air resistance devices are used to increase the resistance value and reduce the speed. However, in the case of this plane where the accident occurred, it is known that one engine had some problems due to a bird strike. In this case, there is a possibility that the speed may have been increased a little more because the landing should be done with only one engine or balance when landing the speed. Pilots say that these things were not rather decelerated, but rather balanced and normal landing. So I can guess that the normal speed, the speed of landing was a little higher than the speed I mentioned earlier. So many people look at these situations and question whether the deceleration was not done properly, but I can tell you that these were the way to control in a normal emergency situation.

[Anchor]
What are some ways if it was a normal situation? There's also a way to slow down.

[Lee Young-joo]
How to Decelerate As you said, we talk a lot about problems that the landing gear itself is not unfolded, but the landing gear itself is not a decelerating equipment. Rather, this is a device that helps the aircraft to settle well on the ground because the wheels come out. However, in the process of rolling these things due to the wheels, devices that strongly adjust various air resistances operate and brake the aircraft. Even now, if there is no wheel in fact, it is possible that this braking itself is much less likely than it is actually operated by the wheel. Also, if it is a situation that slides rapidly like this, it is likely that it has not been controlled, so it would be correct to assume that such dangerous situations and such things have led to great damage to the accident.

[Anchor]
I don't think it would have led to this big disaster if the fire hadn't occurred, but would it be possible to say that it led to a fire as soon as it crashed?

[Lee Young-joo]
Witnesses and witnesses at the scene state that flames within seconds of hitting the wall led to the explosion. Perhaps because of the strong frictional force, the flames, the fuselage itself, collided with the wall in a very heated state, causing defects or cracks in the aircraft, and the fire spread to it, and I think it was caused by explosive combustion. So, as you said, if the fire did not occur, there is a clear possibility that it would not have led to such a large number of casualties if rescue and escape were possible while stopped by a strong impact. However, in any case, the fire broke out and the situations in which the fire broke out actually contributed the most to raising the overall human damage. It is correct to say this.

[Anchor]
In fact, the accident happened around 9 a.m. this morning, and you've been watching the accident with us since then, right? After that, the fire department was dispatched, and how was it to see the process of dealing with the accident? Such processes.

[Lee Young-joo]
In fact, it is confirmed that it took about 45 minutes for the fire to be completely extinguished immediately after the fire broke out. In the event of a fire, in the case of an airport, all airport fire teams are deployed at the airport itself to fully prepare for the emergency or danger of aircraft fire. That's why if you said there was an abnormal landing, you would have been prepared for these parts. If the aircraft has already stopped, you can probably see it as a situation where you arrive at the site as soon as possible and extinguish the fire. It's very skeptical that, even if the fire had already been put out quickly, because it was so fast in the early stages of the explosion that the fire was formed so strongly that it could have saved more people, for example. Because the fire grew so strongly in the early stages and was exposed to the fire, it would have been difficult for these parts to be contained faster or for activities on the site.Even if Ma said he did, there was a clear limit to significantly reducing casualties. You can see it like this.

[Anchor]
It was an inevitable situation. to reduce accident damage I don't think it's easy to put out the flames in case of an aircraft crash. We saw it on the video, and we saw the aftershocks continue. Are there any precautions to be taken in combating the fire?

[Lee Young-joo]
Aircraft accidents actually form a very strong fire when a fire occurs. This is because aviation oil, which is mostly burned by fire, is much more energy dense than regular gasoline and these oils. In short, it's not like it's explosive, but it's very flammable when it burns, so it's the heat from it. Since it is the type that forms a strong fire, it is generally difficult to turn it off with water because it is an oil fire, and it is very difficult because it is a very strong fire. Therefore, it is the most common situation to suppress these special equipment, which can suffocate, block radiant heat, and cool down through special vehicles. However, when a fire breaks out inside an airplane, it is a fire that occurs from general combustibles, so try to extinguish it with fire extinguishers or things in it. Anyway, I understand that the fire was suppressed by using special equipment foam extinguishing facilities and other things that the airport fire brigade had in it.

[Anchor]
One of the most curious things about the cause of the accident right now. Isn't it that the landing gear landed without spreading out? First of all, that was the screen we could see, but why didn't the landing gear open?

[Lee Young-joo]
That's actually a very questionable part. This is because the landing gear itself is operated by the hydraulic device, which is now estimated to have caused problems in the hydraulic system due to the occurrence of bird strikes on the engine in advance. That's why I'm assuming it didn't work. However, the problem is that these hydraulic facilities are actually installed one by one on each side, so even if there is a problem with one side, the other side is supposed to operate to maintain the functions, but it seems that both of these methods were not possible. So, in fact, there are some people in the technology sector who wonder if this is a possible situation if both sides have problems.

[Anchor]
To the naked eye, it seems that one engine had an abnormality on the screen, and the other engine was actually invisible when landing, but if there was an abnormality in one engine and the other engine operated normally, would that be directly connected to the reason why the landing gear did not unfold? In fact, the Ministry of Land, Infrastructure and Transport said earlier that even if there was a bird collision, there was no connection or connection between the two accidents.

[Lee Young-joo]
That's right, because two bird strikes occur at the same time on both sides is actually very difficult to occur in terms of probability. So we can't rule out the fact that both of these engines lost those functions at the same time and at the same time because of Bird Strike.Ma is a very difficult situation to occur probabilistically, so it's a very slim possibility to say that the landing gear didn't work because there was something wrong with both hydraulic facilities due to this situation. However, aside from that reason, the landing gear was not working, so these were actually situations in which they had no choice but to try to land the fuselage. And in the process of landing the fuselage, we believe that there was a very urgent situation in which we had to turn around again and land immediately within almost two minutes at the time when we actually requested Mayday by Bird Strike.

[Anchor]
So what happens if the landing gear doesn't work properly? Will the risk of accidents increase like this accident?

[Lee Young-joo]
That's right, because as I said before, landing gear does these things to allow the wheels to come out when the plane hits the ground and land smoothly. In short, if you don't have this part, it's a situation where you have to just fall off your body as I said before. In fact, things that do not have this part are situations where the plane has to receive very absolute shocks for landing, and the first thing to do is to receive a proper impact. The other thing is that if the deceleration parts are done correctly during deceleration, this wheel part must be transmitted and deceleration must be achieved. In any case, the fact that the landing gear did not work can cause a serious and fatal problem for a normal landing, apart from deceleration. So, when landing gear is not working properly all the time, how to control it in various emergencies, and how to operate it manually. This is because it's actually that important that airplane pilots always train and prepare for these things.

[Anchor]
The question I'm trying to ask now might be useless in a way, but after landing, we slid all the way onto the runway as we tried to land the fuselage. But the runway is like very hard asphalt, so there's a lot of friction. But what if the brakes didn't slow down to the point where it didn't seem to have worked at all, and if it went off the runway, what if it went off to the grass or dirt, not asphalt, let's just guess.

[Lee Young-joo]
It doesn't actually slide all the way as you said. In short, if you've had that problem by moving over or turning around, it can be a little difficult to get around the possibility that it's been safely stopped. Because in a situation where the road surface is clean like a runway at high speed, the resistance will be small, but it will be pushed out more.If there are irregularities on the floor or if there are various lumps, such as, there is a clear possibility that those parts can shock or hit the fuselage and lead to gas defects or fires. Because even small objects, rocks, and other things on the runway could actually be lightly splashed, and in fact, these parts could be strongly impacted and appear as unexpected defects. In fact, it would be correct to assume that even if the gas moved to another space outside the runway, it would not have been a safe situation.

[Anchor]
Then how do you see that? First of all, it's 323m from the end of the runway to the outer wall, but for now, I kept going straight, bumped into the outer wall, hit the outer wall, and the fuselage was completely damaged and didn't it cause a fire? Questions about the outer wall are also being raised a lot now, but isn't it too strong?

[Lee Young-joo]
But it's a little hard to actually look like that. If you look at the shape of the outer wall, it looks like a wall made by stacking block walls. The wall itself is not so tightly physically protected or a wall with this kind of performance. Also, the purpose of building the wall does not seem to have been created for this purpose, such as defending or blocking the aircraft. However, it seems to be a wall with this characteristic of a fence to mark the boundary of an airport or the boundary of a runway. So, as I said earlier, even if it was a smaller, less powerful wall, if exposed to such a strong impact at such a high speed, there is a good chance that it could cause defects in the gas or problems with the gas, so it is a little hard to agree that this wall itself was too solid.

[Anchor]
Many people say bird collisions as the cause of accidents, but do they occur more during bird collisions and takeoffs and landings? Or does it happen a lot in the sky?

[Lee Young-joo]
In the actual situation, there is a much more possibility of taking off and landing. Rather than leading to more accidents, it is more likely that such an occurrence is high. It would be correct to see it like this. Basically, the height of the birds' activity is about 1km from the ground and about 900m. That's why most airplanes fly at a higher altitude than this, so these possibilities of exposure to birds during take-off and landing or, in fact, are not relatively high. On the other hand, since there are many birds in wetlands around the airport and places formed such as pastures here, the possibility of bird strikes that can lead to accidents is much higher during take-off and landing because there are more movements and movements of birds near the airport.

[Anchor]
So don't all airports have such devices to prevent birds and birds from accessing them?

[Lee Young-joo]
That's right. For example, shooting, or using sound to block birds from approaching, even though humans can't hear it, they fire uncomfortable sounds at birds. In short, we're also using these lights to keep birds away from us when airplanes take off and land. But the problem is, I hope the birds move as we intended anyway.Ma is also not in all situations, so there are situations like this that temporarily move and then come back, so there is a limit to seeing that 100% of the work of chasing birds is done perfectly. It's right to see it like this.

[Anchor]
I usually looked at the time order of the accident today, and you issued a bird collision warning at 8:57 a.m. Be careful. And two minutes later, Mayday, that is, we asked for help. What kind of situation is this? What was the situation back then?

[Lee Young-joo]
As you said, we approved the landing normally and it seems that it was a process of preparing for a normal landing. However, in this situation, parts of the collision and strike prevention risks of birds at this time were notified. However, this notice is not about taking action against these birds, but about bird strikes, so you can think of it as the concept of landing normally while preparing for these things. So, maybe in this situation, a bird strike occurred in the meantime that Mayday occurred just a minute or two after such a warning came out during the landing process. So various problems arose with the aircraft. That's why I'm assuming that it was an emergency. After that, one of the things that many people are wondering about the flight's actions was that it would have been a little more normal if it was a situation where we were in a hurry and prepared to land and land again. After a bird strike like this, it turns to the runway right next to it within two to three minutes and lands right on the runway. At this time, there are some parts that are very urgent in terms of time, such as the bypassing rotation angle. However, it is difficult to see this urgency as simply a mistake of control or manipulation. There must have been some reason why I had to land like this urgently. I think there is a possibility that such judgments will be made. However, these situations seem to require a process of figuring out what was wrong with the aircraft or what was the emergency with audio recorders, communication contents, and data that can confirm the judgment of the situation at that time.

[Anchor]
So, when you usually say that there was a plane accident or almost a plane accident, if you look at the situation at that time, the plane is about to land and then takes off again. And you turn around and use up all the fuel in one way or another, and then you try to land again, and you buy time during that time. So I try to contact the control tower or talk to the authorities to find a solution, but the first attempt was at 8:54 and I couldn't take off again, right? It went back up and after that, a bird warning came out. So first, do you think there was something wrong with the previous one? How do you think about it?

[Lee Young-joo]
It's hard for me to judge hastily that there was a problem in front of me. However, there was a warning of a bird strike in the process of coming down like this, so I think that the bird strike has already occurred in the process of turning again without the first landing of the first flight.

[Anchor]
Possibility that the failure of the primary landing was already the primary cause of Bird Strike.

[Lee Young-joo]
It's possible that it was. Because the 2nd landing attempt was very urgent, I think it shows that there was a problem during the 1st landing process, so there was not enough room to solve the problem and land again.
So it's actually hard to judge these various changes in the situation by time, these things, these things are still known because of the lack of information.In fact, these things require investigation and analysis by closely looking at flight records and communication details by time.

[Anchor]
Then what do you think of this? I also asked someone else. First of all, there's a video that the viewers caught under the plane. In the meantime, flames and smoke came out as if the right engine had broken down due to a tide, so why did the viewer film it? So first, there are other abnormal symptoms and the plane is weird, so you may have caught it while filming. Is that why the bird crash was 1st and I couldn't land after that. What do you think of this as if something is the primary abnormality and then there was a bird strike, a possibility?

[Lee Young-joo]
So, it is necessary to check whether the time when the video was filmed was the process of trying the second landing or the process of trying the first landing. Anyway, if I look at these situations, the person who filmed this video wouldn't have expected that there would be something wrong with the aircraft itself, and I think I took it while watching the situations with something wrong. Then, in fact, it can be seen that it was taken during the second landing. Or, for example, there is a possibility that such situations may have been confirmed in the process of filming these things on a daily basis because the plane about the aircraft passes upward. So actually.

[Anchor]
I wonder what kind of situation the person took it in.

[Lee Young-joo]
In fact, it is necessary to check whether it is the first landing process or the second landing process as you said. However, there are two crew members who were rescued, and according to a statement later made by the crew at the hospital, there was a bird strike that caused one engine problem and caught fire. If that's the case, it might be more correct to think that it was the process of preparing for the second round after going back up because of that situation in the first round. So this part needs to be more about the situation.

[Anchor]
Even if it is primarily caused by a bird collision, there is also a possibility of additional airframe defects or maintenance defects. First of all, Jeju Air said that it has no history of accidents and no airframe defects have been found. The accident investigation committee collected the flight recorders, can this alone determine the cause of the accident?

[Lee Young-joo]
Basically, as you said, there are two types of black boxes and accident recorders. One is voice information, so communication between the control tower and the pilot, and communication between the pilot and the assistant manager are all recorded and stored. Therefore, you will be able to check the abnormal situations and how these abnormal situations were communicated with each other and how they were controlled and controlled. At that time, flight recorders were able to check the altitude of the plane, the normal route, and then the abnormalities of the plane's system, so if you look at these two records together, you can actually come to a conclusion about these things because of what factors. However, as you said, it is possible to check whether these parts are defects in the gas, or whether these parts are not defects in the gas, or whether the gas was normal but various maintenance problems.

[Anchor]
If the location of the accident is Muan Airport, what are the characteristics? So, this is located in a place where most airports are located along the sea, so can you capture the characteristics of Muan Airport? What do you think?

[Lee Young-joo]
In the case of Muan Airport, the characteristics are not much different from other general airports.Ma has a lot of wetlands around here, so there's a lot of migratory birds, so there's a lot of birds, and of course, most other airports actually have more birds than nearby areas.Ma was said to be a place where more birds live and are observed, especially in this area. According to another survey, there were also media reports that Muan Airport had the largest number of accidents related to birds. If you look at these things, in fact, even if bird strikes and strikes don't occur, the risk of these birds is a little higher than other places.

[Anchor]
How about the runway? There was a lot of controversy over the length of the runway.

[Lee Young-joo]
In fact, it is difficult to say that the length of the runway was very dangerous. The length of the runway related to aircraft, such as airports, is not simply set by separate standards in Korea. In most international airports, the length of the runway of the aircraft is determined by international standards. If the runway length that a
heavy aircraft can land is about 2400-2800m. That's why Muan Airport adheres to 2,800m standards in accordance with such standards. Many people say that it would have been safer if the runway had been longer because it is not just a situation where a plane lands and exits under normal conditions, but it is difficult to say that there was a problem with the runway itself if it was a safe distance standard that is recognized and used internationally.

[Anchor]
I see. I've heard your expert help. This has been Lee Young-joo, a professor of fire and disaster prevention at Kyungil University. Thank you.