179 dead in Jeju Air disaster...The largest number of domestic airliner accidents

■ Host: Anchor Chung Chae-woon and Anchor Cho Ye-jin
■ Starring: Yeom Gun-woong, Professor of the Department of Police Fire and Public Administration at Yuwon 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]
The Jeju Air plane disaster at Muan International Airport in Jeollanam-do remains the most casualty-related accident in Korea. Let's talk in detail with Yeom Gun-woong, a professor of police fire administration at Yuwon University. Please come in. A very unfortunate accident has occurred, so please explain this accident first.

[Yum Gunwoong]
There was an accident yesterday morning. It was an international flight from Bangkok, Thailand to Muan, Jeollanam-do. It's a Jeju Air flight with a Boeing 737 plane. It was originally scheduled to land at around 8:20, but at this time, a bird collision occurs 200m above the sky. So I collided with a flock of birds while preparing to land and the right engine is flaming. So, I give up landing and communicate with the control tower while circling the sky. So, after the first landing attempt, it's called Gore-Round, and it develops into a situation where it repeats itself and even makes the second attempt. I tried to land around 9:05 and there was a fire in the right engine. At this point, we try to land the fuselage. In the end, in the process of attempting to land the fuselage, the runway of Muan Airport was about 2.8km, but it went all the way without slowing down to the end of 2.8km. So there was a structure, and there was an outer wall. So the collision with the outer wall led to a disaster in which the aircraft broke into two and many victims occurred there.

[Anchor]
Presumptive is one of the biggest causes of this accident, as you said, a bird strike and a bird strike. This Muan Airport was one of the airports with the highest rate of bird collisions.

[Yum Gunwoong]
Because there are migratory birds in the nearby area. For this reason, this is a migratory bird island, and it was an area that raised questions about the appropriateness of the airport. There have been previous discussions about whether the airport should have been built in another area, and there have already been questions about its feasibility since the airport's construction stage. And recently, in the case of migratory birds, a lot of winter birds are moving, and since this area is a migratory bird, there is a possibility that it may have provided the cause of an aircraft collision in the morning. When migratory birds come, there are many activities in the morning and evening while flying. Because we take off in the morning to find food and return home in the evening, the amount of movement increases in the morning and evening. Since the time of the accident is also known to be 9:03-5 minutes, it is highly likely that migratory birds moved in large groups at this time. However, even if you watch the current video, you can see the collision video. On the right engine side of the aircraft, we see something that is believed to be a migratory bird. So, the possibility that migratory birds hit by aircraft and that the engine was stopped by bird strikes and migratory collisions. And it is presumed that this eventually led to the aircraft having no choice but to make an emergency landing.

[Anchor]
However, as you said, some pointed out that if there are many birds in the main bus of Muan Airport, there are bird detection radars or countermeasures in place at the airport in the first place.

[Yum Gunwoong]
Civilian airports and military facilities that operate aircraft also make a lot of efforts to chase migratory birds. They actually set up a scarecrow. Some shoot horror bullets to scare birds away. So, I usually make efforts to drive out migratory birds. Obviously, we expect these efforts to have been made at Muan Airport. However, migratory birds suddenly move and appear, so the damage caused by migratory birds is very large. In the case of Korea, according to the data reported to the National Assembly by the Land, Infrastructure and Transport Commission, the number of aircraft collisions caused by migratory birds has reached 623 in the past five and a half years. You can think of it as a lot. On average, I think we can look at about 100 cases a year. Then, about 100 aircraft crashes a year have not led to major accidents so far. This aircraft crash can cause engine, hydraulic system, and electrical system failures like yesterday's accident, but it can also be simply hit. In such a case, the contents do not lead to a major accident, so I think yesterday's accident led to a major accident and a disaster due to a combination of various coincidences and accident environments.

[Anchor]
Bird strikes are a phenomenon that occurs a lot around the world. It is said that even if it collides with a small bird, the strength is very high. What is the reason for that? It depends on

[Yum Geon-woong]
altitude. If you go up to a high altitude, birds with high flying capabilities of hawks and sparrows are large. So when these birds collide, they are rather shocked. If the altitude is lowered further, for example, if a mallard with a speed of 370km/h 900g hits, it will receive a weight impact of 4.8 tons. It's actually a shock of tremendous intensity. If a bird collides while the aircraft maintains an altitude at a very high speed, it will be very shocked. Particularly problematic is when the current flows into the engine and collisions occur. Then, in the case of aircraft, there are cases where these devices work because there are electronic devices, hydraulic devices, and electronic instrument devices to maintain altitude. In fact, even in the case of yesterday, there is a very high possibility that all electronic and hydraulic devices were stopped due to a tidal current collision. Because if you look at the causal relationship yesterday, the Ministry of Land, Infrastructure and Transport also said that the landing gear would not have been damaged by engine damage. Then, in the end, the landing gear does not open in a few minutes, so it has no choice but to land quickly. So the situation where pilots have no choice but to land on the fuselage here is that the engine may have been damaged by the damage to the device, and not one, but both. Because if two engines stop, all the devices here stop. The auxiliary device called APU does not work and all electronic devices stop operating. If that happens, the landing gear won't come down. It's supposed to come down automatically.

[Anchor]
Can't I get off manually?

[Yum Gunwoong]
Getting off manually can be done manually by gravity, which is known to take about 30 seconds. Then you can assume that you didn't even have time for 30 seconds. With the landing gear itself unable to be lowered manually. For example, two engines were damaged and all the devices failed, and then the landing gear did not come down manually. And there is a possibility that it has led to a situation where you can't buy time. Another possibility is that. In the case of Boeing 737s, there are three landing gears on the floor. There are two at the front and two at the back, and you can think of the landing gear as the wheels come down. The wheels went up when I took off and landed.It's going down and down, but the wheels are exposed to the outside. What I'm talking about is that even when it's folded, there's no wheel cover. What I'm saying is that bigger aircraft are supposed to cover the wheels. When you go up, the wheel goes up and the cover covers underneath it. When you look down, you can't see the wheels. Larger aircraft. But in the case of this aircraft, it is known that the wheel is visible. Then, since the wheel is visible, we assume that the bird must have crashed yesterday when we saw it on the screen, but the fact that both of them may have had their engines damaged was that the control tower warned them a few minutes ago. It is possible that a flock of birds was not just one bird, but several birds. Then, it is possible that several affected one or two aircraft engines as mentioned earlier by the collision. So the first possibility is that electronics or hydraulic devices have failed. The second is that the birds may have damaged the landing gear in the area I explained. What are you talking about? It crashed into the landing gear and the landing gear can manually come down in 30 seconds, but there is a possibility that even the landing gear did not come down at all because the landing gear was broken. Because it is a screen that was taken from over 200m above the sky, even if you pull it by zoom from here, it is difficult to analyze everything with an accurate screen. Therefore, the rest of the flight records or damage should be determined through voice recording and flight recording devices, and accident investigation or accident cause analysis should be continued accordingly. It's all just an estimate for me, too. All the records were not confirmed by the Ministry of Land, Infrastructure and Transport. However, I'm telling you that these possibilities exist because yesterday's accident led to a major disaster.

[Anchor]
The story that keeps coming out in the media is that there may have been an engine failure due to the current hitting the engine. And what the professor just said is that since the lid of the model is not covered on the landing gear side, the tide may hit it and the landing gear may have broken down, suggesting this possibility. Even if the bird collision was the primary cause, it does not rule out the possibility that it was defective on its own, right?

[Yum Gunwoong]
I can't rule it out. If the maintenance was done properly there when they came back to Korea from Thailand. Or whether it was properly maintained when going back to Thailand from Korea. This maintenance needs to be continuously maintained every time the aircraft takes off. Therefore, preventive maintenance or occasional maintenance should be carried out, but we cannot rule out the possibility that such maintenance has not been done properly. Whenever you look at aircraft accidents, the accident rate due to bird collisions is also very high. Next, there are many accidents due to poor aircraft maintenance. Then there are definitely accidents caused by the pilot's inexperience in controlling. So we can't rule out all of these causes of accidents. All of these things have to be put together assuming that any cause of an accident or any factor can work. As you said, we also need to find out whether there is a maintenance failure. I think it will take a very long time to investigate that part. As the Ministry of Land, Infrastructure and Transport said yesterday, basically, it takes at least six months to investigate aircraft accidents. If it gets longer, it takes up to three years. Because it is a Boeing aircraft in the United States, U.S. engineers have to come in and check the aircraft together, and there are many parts that need to be checked. So in these areas, YTN reported earlier that the first investigation began in Korea. During the first investigation, it is expected to check various airframe defects or maintenance defects.

[Anchor]
There are still a lot of questions left. You tried to land the fuselage. But I tried to land the first time and came back right away and tried to land, but the situation was very urgent, right?

[Yum Gunwoong]
That's right. It was a very urgent situation. There are many different manuals that don't have to land on the fuselage. What I mean is that if a bird strike occurred and a gas defect occurred, there are two engines, and even if only one is alive, it will remain able to operate in the air. If that were the case, the control tower would have suggested another option. Turn around a little bit. Assuming there is fuel, it turns around, and in the case of Muan Airport here, the runway was very short. 2. They are airports in the Seoul metropolitan area with different long runways because they are only 8km away. For example, Gimpo and Incheon International Airport are about 3.6km long. There would have been a way to guide them to these airports and try to land the fuselage because it's extended by about km. I would have suggested other measures, but in yesterday's situation, it must be assumed that the aircraft had a very large air defect, leading to a situation where it had no choice but to land on the fuselage here. Unfortunately, the Ministry of Land, Infrastructure and Transport said that the length of the 2.8km runway at Muan Airport is not a problem in international standards, but this may mean that it is safe enough to secure 2.8km when landing with the landing gear lowered, but I personally question whether it was the path we assumed to land on the fuselage. Because yesterday, it came out as a result. Eventually, the aircraft was dragged over 2.8km. Because there was an outer wall at the end, it collided with that outer wall. So there are many other manuals when landing the fuselage. So I put special foam underneath. So, we put special foam on it to control drag, adjust the coefficient of friction, and then adjust the fire to prevent it from getting bigger. They even lay sand if it's urgent. To generate friction. But it seems that none of those things were done yesterday. In particular, aviation oil has other additives because it has high octane levels. Aerial oil is used to add special additives to function normally because the higher the altitude, the lower the temperature. So, in the case of aviation oil, when a fire occurs, it does not spread slowly, but explodes. It explodes so much that even in yesterday's accident, you can see the aircraft exploding in two rivers. So, in the event of an explosion, it is most important to secure golden time to escape right away. Yesterday, it exploded right when it collided with the outer wall, leading to a big fire, so I couldn't even buy time to escape. In particular, many casualties were inevitable because the outer wall broke in two and passengers were bouncing off. So what I told you is that even if we had to meet the international standard of 2.8km, assuming that the fuselage landing was only 2.8km, it is possible to assume that we could have been dragged a little more and stopped at some point after passing through the outer wall and having a lawn or sand field. So, even if we couldn't lay the foam or sand, assuming that there was a sand field or grass at the end of the fuselage landing, I'm telling you with regret that we could have avoided this unfortunate situation. In fact, in the case of Muan Airport, the Ministry of Land, Infrastructure and Transport discussed the extension yesterday. I made an announcement that we are having discussions about the extension. In fact, as far as I know, it fits the international standards of the airport, but the Ministry of Land, Infrastructure and Transport also felt that 2.8km needs to be extended a little more. I understand that there was definitely an extension discussion because I thought about it.

[Anchor]
I think we should open up various scenarios and talk about them. I requested the May Day Declaration at 8:59 a.m. Shouldn't this pilot be responding on the ground after making the May Day declaration? It's the same in the fire department. How do you see the response on the ground?

[Yum Gunwoong]
Yesterday, it seems that there was no response from the ground if we put together videos and other data. Because in a fuselage landing, the pilot declared that Mayday could not control the aircraft in the end. In that case, I'm asking you to get all the available resources up and running. Then we have to prepare for landing. In particular, the safety of the runway landing on the fuselage. Then the available equipment and resources that allow immediate implementation of measures to save passengers. And the equipment and resources to put out the fire immediately in the event of a fire. There should have been things like this right away. As far as I know yesterday, the fire department was dispatched and the suppression was completed 45 or 47 minutes later. It has no choice but to say that the fire fighting equipment that was initially secured at the airport was not extinguished. Then, is there enough manpower there to fight such fires? And it seems necessary to check whether measures have been taken properly during the crash process.

[Anchor]
This time, let's talk about equipment called localizer. It is said to be a device that induces aircraft landing. It is usually installed on the floor, but it is said that Muan Airport was installed on concrete on a pile of dirt. How do you see this part?

[Yum Gunwoong]
Usually, airports are not installed on the dirt floor. It's all installed on concrete, but it's still presumed from what YTN says.In this regard, I think we can't rule out the possibility that this airport was insolvent. As I said earlier, the maintenance of the aircraft has not yet been raised, but Jeju Air has announced that it has been well maintained, but it is also a matter we need to look into, so we need to pay attention to how safety facilities at the airport are in place, equipped, and secured. Here, the localizer was on a pile of dirt in the case of Muan Airport. If you say that there were things that were installed on the concrete floor here, it's the point that these things were not kept to the basics.

[Anchor]
I heard that there is a device called Reverse Trust, what role does this device play?

[Yum Gunwoong]
the Libertarian Trust Among the various equipment of the aircraft, there should be a fuselage landing and these devices. I'll check this part, too.

[Anchor]
I think we need to check whether this part is working properly. Three minutes after takeoff and eight minutes before landing. It is said that the risk of an accident is the highest at this time, but for what reason is this?

[Yum Gunwoong]
It's most dangerous when you take off and land. The aircraft itself is geared to all electronic systems and hydraulic systems running at high altitudes. That's why it's safer when you're driving at a high altitude. Because there are automatic navigation systems and functions called Autopilot, those who have been on aircraft at high altitude will know. There are cases where it shakes greatly due to air pressure, and the situation is not that dangerous. This aircraft itself has a streamlined airframe structure. Various electronic devices are sufficiently capable of withstanding air pressure, but the problem is that the main role of the aircraft is floating in the air, so you can think of it as a newborn baby when traveling on the ground. In fact, the most important thing in the process of landing the fuselage is that the landing gear has to come down. You can think of it as a brake-like device of a car. So, it actually depends on the aircraft, but it operates on the ground with a brake pedal under the pilot's foot and a device that stops like a car by pressing the brake pedal. So, because these equipment is used to take off and land, the risk of accidents increases very high between 3 minutes after takeoff and 8 minutes before landing. There are also a lot of accidents that actually happen around this time.

[Anchor]
Today, the Ministry of Land, Infrastructure and Transport is expected to move the black box of the aircraft to the analysis center in Gimpo to review whether it is possible to analyze it. What will be included in this black box?

[Yum Gunwoong]
There are two voice recorders and two flight recorders. Yesterday, at first, a flight recorder was collected, and later, all voice recorders were collected. Flight recorders have 3D flight records. That's why the flight records, including this 3D record, remain for up to several tens of hours. So we can secure that record to see what kind of problems the plane had and what kind of mechanical defects occurred on the flight path. Also, the voice recorder contains about a day of voice conversations, including the captain, the assistant manager, the pilots, the conversation with the cabin crew, and the control tower. So, the voice recorder can be the first keyword to tell you what kind of problems there were. That's why you can check these things and analyze these things more closely through the flight recorder. Since there is a test and analysis center at Gimpo Airport in Korea, we will analyze it first here, but when I checked the contents yesterday, I heard that some black box devices were damaged. Then it might not be possible to analyze. If that happens, you will eventually have to send it to the US Aviation Administration and request an analysis from there again. They also ask them to analyze the black boxes of accidents and airplanes all over the world. It means that the accident is very urgent and a big accident, but it may not be able to analyze it right away. It can take up to a year. The time of the black box record itself. So I think it would be a relief if these things could be analyzed in Korea. You have to quickly investigate the accident and analyze the cause to recover from the damage to the victim's family. If it is difficult to analyze in Korea, I know that we will request the United States to conduct the analysis.

[Anchor]
We hope that the cause of the accident will be identified quickly and clearly as soon as possible. So far, I've talked with Yeom Gun-woong, a professor of police fire administration at Yuwon University. Thank you for saying that.