Muan Airport Aircraft Accident Expands Search Scope

■ Host: Anchor Sung-gyu Sung-gyu and Anchor Park Se-mi
■ Starring: Professor of Safety Airport in Eul-gu, Hameun-gu District

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

[Anchor]
Then, this time, we will continue to update you on the Muan Airport aircraft accident with an expert. He is a professor of safety engineering at Hameun-gu District. Please come in. All but 179 passengers and two crew members who were rescued earlier have been confirmed dead. How do you see this accident as a whole?

[Hangeungu]
As many viewers know, landing was attempted in this emergency situation called fuselage landing without the landing gear operating properly due to an unknown cause. In the process of attempting this, I can tell you that it is an accident in which 179 people are killed, except for two rescued passengers, who were unable to slow down the runway and collide with the airport's outer wall.

[Anchor]
The most curious thing right now is the cause of the accident, but we keep checking that screen with our eyes, but the cause has not been clearly identified.

[Hangeungu]
That's right. The most direct cause is that the so-called aircraft wheels have not been deployed properly because the landing gear, which is actually witnessed with the naked eye, has not worked properly. Second, even if there is an emergency landing, or a fuselage landing like this, there are many cases in which most passengers are killed in an accident like this in many cases. However, the problem is that in the process of making an emergency landing and a fuselage landing, it collides with the outer wall of the airport. In this process, it is believed that a very high physical impact was received, and in addition, the fire was caused by a series of fires, causing as much damage as it is now.

[Anchor]
Some people say that we should have circled enough to return to the port, but we didn't have enough time, so what do you think?

[Hangeungu]
If you look at the communications with various known control towers and things like this, the order to return to service has been issued. And even though you have to raise your altitude to a certain degree and turn around...

[Anchor]
Returning port means taking off again, going around once, and landing.

[Hangeungu]
That's right. We can say that the process of gradually lowering the altitude by preparing for landing and then raising the altitude again without the landing gear working properly is a return. There was some instruction, so this seems to be the part where the pilot's attempt to return to the port was not smooth. So, not this part of Runway 1, which was originally known, but Runway 9, so much of it should have been turned wide and kept at a high altitude, but now this part is not smooth and in the process of turning, the retry was made as you said.

[Anchor]
If you look at the graphic and explain it, it's been recorded since 8:57.Aren't you saying that Ma made the first landing attempt at 8:54? But now, at 8:57 p.m., the control tower alerted the bird crash warning, and two minutes later, at 59, the pilot sent out a rescue signal, Mayday. And I'm just looking at it now in chronological order. And two minutes later, we tried to land using the opposite runway, and we didn't succeed, and we hit the outside wall, and we ended up with a big accident. So, what happened between 8:54 and 9:03 when the landing was first attempted, and the time when it finally hit the outer wall for about 9 to 10 minutes? Isn't this the key right now? Those nine minutes.

[Hangeungu]
That's right. As the anchor explained, if you divide it by time zone, the control tower has issued a warning about bird warnings to the aircraft around 57 minutes now. However, as many people say, it seems that the airport and most airports were at the level of caution about birds. So, it seems that at that time, whether there was a direct impact on birds or something like this should be investigated accurately. However, as you said at that time, there was a problem with landing, so you had to order the return and raise the altitude of the aircraft to the turning altitude for this return, so if you look at the conversation with the control tower, it is known that this part is not smooth. So, we can't turn at a sufficient altitude and go around the trajectory of about a half and try to land again around 9:01 as you just mentioned. In fact, during the process of taking off and landing, the landing gear does not work, and an emergency landing called fuselage landing is attempted, and the runway is operated for about two minutes and then hit the outer wall.

[Anchor]
So there are various stories about the cause of the accident.Is the Ma bird collision first or the landing gear not coming down first? That's why I returned to the port, collided with a current while returning, or collided with a current, so I couldn't land and came back up. Isn't this part clearly not coming out in time?

[Hangeungu]
That's right. Anyway, it is believed that the landing gear did not start even during the first attempt.

[Anchor]
Is that before or after colliding with a bird?

[Hangeungu]
In fact, it's a matter of whether the collision with the so-called flock of birds actually occurred.

[Anchor]
From the screen, we kept looking at the screen with white smoke on the right engine. You're saying that it's not clear whether the cause is a bird collision or not, right?

[Hangeungu]
That's right. The part where the sparks fly and spark over there, for example, as the algae go into the engine room or something like this, the bird burns and it can be seen as an abnormal form of combustion. In this part, it is necessary to accurately examine various black boxes and things like this. Among the various interviews, there are people near the airport who say that no flock of birds was seen on the day, so in fact, much of this needs to be investigated from the ground up. But it's known that it collided with a flock of birds.Even so, I can understand to some extent that it actually affected the engine part and these parts, but it's very difficult to say that this part had a very direct impact on the operation of the landing gear. In other words, the reason why the damage is so great now is that the landing gear did not work in the end. So whether the reasoning about that part was influenced by such a collision of birds, as the anchor said, there was an influence of the birds, but whether the landing gear did not operate due to another defect or these conditions, the fact that it did not work anyway.

[Anchor]
In the end, the problem is that the landing gear did not come out, but the direct cause of the fuselage landing was. Why didn't that landing gear come out, you're saying you don't know the cause yet. But if you think about that screen again, wouldn't that be a picture taken by an ordinary citizen anyway? With a cell phone. But I don't think he did it on purpose to film it colliding with a bird. I think they captured this and that scene because the plane was working something weird. So, before that accident, before that right engine accident, I think there was an abnormal operation and movement of the plane.

[Hangeungu]
That's right. In fact, if you look at the contents of the conversation between the control tower and the pilot and look at these parts, it seems that it is possible to identify the cause to some extent. And the landing gear proceeds by checking those parts before actually landing. In that situation, the pilot also recognized that the landing gear had not been deployed, and that's why it's seen as having carried out the procedure called return as mentioned earlier. Anyway, there are various predictions and things like this, but it's important to wait a little calmly to find out the exact cause.

[Anchor]
If so, I think we can check the details of the accident more through the black box. It seems that it takes time to analyze the black box. How long will it usually take?

[Hangeungu]
The plane in question is a commercial flight. The same goes for Boeing, including our country now. And international airlines and investigative committees should be comprehensively reviewed.
That's why many people may be a little different depending on the case, but I think it'll take about 6 months.

[Anchor]
But first of all, since two crew members survived, and communication is possible. There was also a briefing on the current status of male flight attendants.Ma said that in the case of female flight attendants, a bird collision was the cause of the accident. So after one engine smoked, it exploded and then it seemed like it was falling, he testified like that. So, the black box is also a black box, but there were two survivors and that was a flight attendant, so I think it will help to find out the cause of the accident.

[Hangeungu]
That's right. According to the surviving flight attendant's message, there was actually a problem with the engine, and it was an abnormal combustion form, and the output was deteriorated enough to be recognized by those on board. Even if there is a power drop on the engine or an abnormal situation equivalent to a fire, it is very unlikely that the landing gear can be linked to the engine separately and disabled together.

[Anchor]
Is it not directly or mechanically related to the fact that the landing gear does not unfold just because the engine is out of order?

[Hangeungu]
That's right. Mechanically, all circuits are designed to be structurally separated like this because they are functions for very important components. But, as you said, it's impossible to rule out that related circuits and related systems can be affected in the course of various developments. But basically, everything about safety, such as engines and landing gears, is parallelized. So, the system is set up so that when engine No. 1 becomes a nailer, there are multiple things that can produce similar outputs. So a lot of these systems, which operate to be safe in the event of such a problem, are actually in spatial conditions that are almost impossible to respond to, so a lot of these efforts have been made to dualize and parallelize them.

[Anchor]
Even if the engine and landing gear are directly connected, the left engine is actually not clear to the naked eye right now.E. If there was nothing wrong with the left engine with the naked eye, in fact, the landing gear did not unfold because of the engine, so it's hard to understand.

[Hangeungu]
That's right. In any case, fire or abnormal circumstances may affect the control system that actually controls it, but that possibility is quite low. Because of such structural safety. And even though it was not able to raise the altitude of the aircraft properly turning or returning, it remained level with the aircraft during the actual landing process. What this means is that in the end, it's a very important part of lowering the altitude to the right position and landing the aircraft to the runway, but an emergency landing was attempted while maintaining the level. However, when you make an emergency landing like this, these systems that try to brake as much as possible by pushing back or folding their wings should be operated, but a large part of it just keeps flowing according to basic friction.

[Anchor]
So, there must be various engines for the plane to slow down, but the landing gear did not come out. Landing gear is a tire, but you couldn't put the brake on the tire for now, so you're saying you were able to slow down due to various different operations, right? What is engine reverse propulsion?

[Hangeungu]
To put it simply, the engine operates in the opposite direction. So you can go backwards. So you give it a part of the reverse, basically these braking forces, and hydrodynamically speaking, it actually makes the lower part convex, for example, like a car near spoiler. Then, the upper part will have higher forward power. So if we want to fly, we have the power of the lift, so the pressure on the bottom is high, so we have to push it up. So if you want to land upside down, the air will be pressed from the top. So these devices that increase drag are installed as supplementary devices that reduce altitude and brake.

[Anchor]
You said that's hydrodynamics, but is that the movement of the wings?

[Hangeungu]
That's right. To put it simply, the fluid called air actually moves, so the longer the travel distance, the faster it should be. So what I'm saying is that if you look at the wings of the plane, the top is protruding like this, and the bottom is flat. So the fluid and air passing upward around this wing are long enough to pass through, so the speed will increase. Then, if the speed increases, because of the definition of Berno Equation, if the speed increases, the pressure decreases. So, because the lower part is relatively slow and the pressure is high at the lower part, the airplane floats. Earlier, I gave you a spoiler about the car. So in the case of sports cars, in the case of race cars, the wings are opposite to the wings of the aircraft. The lower part is convex. So if you drive at high speed, you can hear the front like an airplane. So you have to have a near spoiler so that the vehicle can drive at high speed without flipping like an airplane. So it's like you can use your wings to have that effect. These things seem to have not worked properly with the naked eye.

[Anchor]
I'd like to talk to you while looking at the graphic you showed me earlier. So, I was going to take off again and come back, but I was going to try to land again, but I was going to land from south to north using the right runway as shown now, but I landed from north to south. Then, we failed. Don't we have to turn 360 degrees around the runway and come back to the runway?

[Hangeungu]
That's right. According to the general principle, it would be a basic rule to turn wide enough and get back down to the original runway. So, whether the reason why we changed the runway from 1 to 9 is because of currents or these effects, or whether it is a gas situation that cannot be used by returning the runway again, we need to closely examine the cause.

[Anchor]
Because of the length of the runway, the length of the runway is short, at Muan Airport. There was also a story about the cause of the accident because the runway was short. Because as soon as I got off, I didn't slow down enough and received the outer wall. I think that's why it came out, but what do you think of this interpretation?

[Hangeungu]
So it's a difference in perspective of what kind of discussion. As you said, if the runway was actually longer than 3,600 meters instead of 2,800 meters, these physical collisions, called outer wall collisions, could be mitigated or less damaged. In conclusion, it worked. But it's another context to say that the outer wall is a problem. So, as you said, it is calculated that all airports are fuselage landings, so the consideration of sufficient separation distances and such is actually not considered in the current concept. I can tell you this. According to the law, there is no legal problem at all in terms of international airport standards. But if the legal standards established now are reversed, that is, in terms of performance, is it safe in such an emergency situation as sufficient? That's not true. So anyway, it meets the legal and legal standards, but in the process of landing the fuselage as it is now, and in fact, there is not an outer wall, but a simple steel fence or a so-called buffer zone that is very wide in this form, so if there is a certain area, I personally think a large number of people died in the process of colliding with the outer wall. So the risk of that can be very low. In conclusion, yes.

[Anchor]
You said that the length of the runway was sufficiently made in consideration of fuselage landing and emergency landing, but wouldn't the length of the runway change as you attempted the second landing on the opposite runway? Do you have any shorter ones or something?

[Hangeungu]
I didn't exactly check that, but I didn't mean that the length of the runway was calculated in consideration of the fuselage landing. So basically, it's called a fuselage landing, so the runway length is actually, for example, short, so isn't there a set starting point for the pilot to actually enter the runway when the runway length is relatively short? Because I actually have a braking distance. So in some areas, runways can be more stressful with slang than airports. I need to lower the altitude quickly and land exactly at the landing point where I have to start and get off.

[Anchor]
In extreme terms, the U.S. aircraft carrier is a very short runway. Accordingly, technology that is quite difficult to get down must be accompanied.

[Hangeungu]
That's right. And in the case of fighter jets, the battlefield and these parts are quite shorter than general airliners. And it's true that it's accompanied by a variety of devices that actually use the carrier's own wires to hook and finally brake. However, according to the basic standards, a runway of about 2,800 meters can satisfy the legal international airport standards.

[Anchor]
It wasn't an accident because it was short. To view it as a cause.

[∀}{함}What I'm trying to say is that it's short, so it's not a cause, but it worked as a factor to expand the damage caused by this high number of deaths. Without the outer walls, the possibility of a significant number of people actually surviving could increase.

[Anchor]
The professor said this earlier, too.It takes enough time for a clear cause of the accident to come out, and it actually takes that way, and aren't black boxes and voice recorders all secured now? You said you needed enough time to analyze it. Anyway, it was a big accident today, so I hope you understand that we have no choice but to guess the cause of the accident and talk about it while estimating the cause. I saw it in the graphic.How do you see Ma? To continue talking about the runway, you mentioned earlier when the plane finally made the second landing attempt. So, do you think the very starting point where you land, that starting point, has secured enough runway length? Or do you think you put it down in the middle? On the overall screen?

[Hangeungu]
Actually, I don't have the information about the exact location of the landing part. To some extent, it seems that it landed close to the end point I mentioned earlier, and it seems that it tried. Anyway, it's the process of landing. So, in this condition where the runway meets the actual fuselage, in fact, it should have slowed down sufficiently, but there is one part where the speed was quite low. So in the end, there is a brake function on the area where the wheel touches, so if you say a tire, it also has a brake function on the area where the wheel touches, but as you know from the aircraft, you can push it backwards in terms of fluid mechanics.

[Anchor]
It feels like the brakes are on.

[Hangeungu]
These parts show this mechanism that reduces the speed of the plane as it works. But when a lot of people see the actual videos and things like that, other than the so-called braking part on the landing gear, those elements related to braking work properly on the other side. Of course, we need to investigate further, but it's now shown that it didn't work properly.

[Anchor]
In the end, it seems that the collision while running without slowing down the outer wall had a big impact. In the case of emergency landings and fuselage landings like this, would it be a little too much to reduce the speed? Isn't there any way to reduce it?

[Hangeungu]
So, as I said, things like actually pushing back or the process of increasing resistance by reversing the flow of fluid should be done. So one of the unfortunate parts is that the material of the plane itself is the body, and this material itself does not have enough strength to mitigate the impact on the outer wall. So you have to reduce the weight of an airplane. Basically, we use very soft metal called aluminum and it's made up of carbon fibers and things like that, so we actually take into account the various so-called safety packs when a car hits that outer wall, the rigidity of the body that reduces the impact on the collision. However, in the case of aircraft, it has now appeared in the form of an accident. So, there is no concept for this part of reducing the physical exercise of the impact when the outer wall collides. So it's completely Muju-Communist.

[Anchor]
The important thing is to make the aircraft, but you can't make the aircraft heavy or put on a device in front of it in consideration of this collision.

[Hangeungu]
So it came out in the fire department briefing, but quite a lot of the body shape is unrecognizable, so it's affected by more than just the degree to which a car gets crumpled in an accident. Due to the nature of the aircraft's own material, insufficient consideration of these accidents seems to have contributed to the increase in damage.

[Anchor]
I see. That's all for the experts. Until now, he was a professor of safety engineering at Hameun-gu District. Thank you for your help.