"Mayday, Bird Collision" Communication Revealed...launch a joint investigation into the black box

■ Host: anchor Lee Hyun-woong, anchor Cho Ye-jin
■ Telephone connection: Choi Ki-young, professor of aerospace at Inha University

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

[Anchor]
This time, let's point out the questions that need to be solved one by one with an expert. I'll connect with Choi Ki-young, a professor of aerospace at Inha University. Professor, you're out, right?

[Choi Ki-young]
Hello.

[Anchor]
Some of the communications between the control tower and the pilot just before the accident were released. When I look at this, is there a chance of a collision before I get a bird activity warning from the control tower?

[Choi Ki-young]
I don't think so. This is not a small matter in the case of bird warnings, so I carefully assume that if there was a collision, the pilots would have communicated to the control tower and notified it.

[Anchor]
However, rather than immediately making the May Day Declaration, I heard that there are procedures before that.

[Choi Ki-young]
The pilot's judgment is important. So, as I said, rather than disposing of it according to all accidents or emergency measures, it does not immediately issue the problem, but literally serves to inform the surroundings. So, judging from the cockpit, the current situation is very urgent, including all aircraft around and on the ground or in the air, so of course, they will take care of it, but since it serves as a reminder to prevent secondary damage and carry out necessary preparations, I think there will be a procedure to check whether the problem is an emergency enough to notify all around when a problem arises.

[Anchor]
Two minutes after the control tower's warning, there were Bird Strike and May Day Declaration, and depending on the situation, you think it's possible to declare May Day in two minutes, right?

[Choi Ki-young]
Exactly at what point did the bird crash occur, isn't that one key thing? So what happened from the crash to the May Day declaration. If it gets sucked into the engine or the engine is damaged almost immediately, those are problems that can be recognized right from the cockpit. In addition, some parts of the aircraft may be damaged by hitting other parts of the aircraft, and in such a case, if there is no obstacle to flight, I don't think it would have come out until the May Day declaration. So I think we should talk about such judgments and things like that while looking at the data.

[Anchor]
We should also pay attention to the fact that the landing gear did not come down. Witnesses' photos and videos show that the front wheels were operating normally at the time of the first landing attempt. However, the landing gear was not unfolded in the second landing attempt. Do you estimate that there must have been any problems during this process?

[Choi Ki-young]
We have some facts out right now, right? When you watch the report video, you can see that the engine is on fire, and then you walk, but unlike normal circulation, the process of re-landing is very urgent. Then, you slide and hit the localizer. There are facts like this. In fact, there are a lot of parts that we haven't yet connected to in the middle. Representatively, there is a witness that the landing gear problem has recently been lowered in the first attempt between yesterday and today. If that's what we've confirmed, and if it's a fuselage landing when the landing gear is not lowered during the second landing, wouldn't it be possible to say that the landing gear has been folded? However, my estimate is that if there are two engines, even if one engine is turned off, the other engine can lower the landing gear and manually lower it. It is certain that there was a collision of birds between the first and second collisions. If there are many birds in between and some birds are caught in the landing gear storage space, I think we can assume that those could be one of the causes because there was a problem in lowering the landing gear in the second attempt.

[Anchor]
There's also what you said. And considering that after the repeat, they couldn't enter runway 01 again and entered runway 19, so they couldn't take a large radius of rotation, is there a possibility that both engines were abnormal?

[Choi Ki-young]
I also think about that problem first and ask a maintenance expert. In the case of this model, if both engines are turned off, all hydraulics and electricity will be cut off. But if you look at it, in the second attempt, the plane is right in the middle of the runway, and the touchdown point is a problem.Ma sat right in the middle of the runway. So, the process of turning it around and aligning the plane in the center of the runway involves high-level adjustment, so it would be hard to think that the engine would have turned off both in the air at the same time if the adjustment function was maintained to some extent.

[Anchor]
One of the other causes now is the localizer of the concrete structure. Professor, would the outcome of the accident have changed without this, what do you think?

[Choi Ki-young]
Doesn't it start with a flock of birds now and the problem with no landing gear, a few things keep happening in a row? In the case of aircraft, since it is a machine that operates in extreme environments, these various safety devices are double or triple, and in order to lead to such a major disaster, everything has to be connected to cause a major disaster. Likewise, if it were a normal situation, there wouldn't have been any problems, but since the things I mentioned earlier continued, it's hard to say that we're the only one that's the cause of the problem.What is certain is that if the flatland continued without this, the situation would have been different.

[Anchor]
Then, what do you think about the position that the Ministry of Land, Infrastructure and Transport and the airport claim that there is no legal problem because this is not a set standard?

[Choi Ki-young]
I'm just reading the regulations. If you look here, I think we need to carefully examine it with the Ministry of Land, Infrastructure and Transport, but I don't know if this is a useful rule at the moment that the soft ground should be selected and the foundation should be at the same height as the surface.Ma has these regulations in 2012. I think I need to check it out.

[Anchor]
Are you looking at airport safety standards now?

[Choi Ki-young]
It's called the Navigation Safety Facility Protection Manual. I just looked it up.

[Anchor]
In that regard, we will have to wait and see how the Ministry of Land, Infrastructure and Transport and the investigative agency will make decisions in the future.

[Choi Ki-young]
That's right.

[Anchor]
As you said, it's important to consider the rules one by one.There are cases in which preparations are made assuming that aircraft accidents can cause great casualties. So, in the case of localizers, there are cases where materials that are brittle are used in overseas cases. What do you think about that?

[Choi Ki-young]
It is basically set up around the airport of the aircraft. Isn't the local riser now with a support structure and a foundation underneath? The problem now seems to be that the first problem is about 2m thick. When installing the hillside at that time, the influence of the surrounding terrain would have been considered, along with that problem. Then, isn't the structure itself a question of whether to make a fragile plastic material or a very hard steel column? Whether such things are comprehensively judged and followed the regulations. I think the regulations must be comprehensive for those things.

[Anchor]
To return to the story of the bird collision, the bereaved families mentioned the bird habitat near the airport and pointed out that it is not a natural disaster but a man-made disaster. There are talks about the appropriateness of the airport's location, and it is known that this Muan Airport is also an airport with a high possibility of a bird collision, and if so, there is no bird detection radar. So what did you see and send when the control station sent you a bird warning?

[Choi Ki-young]
In the case of the control tower, when the control tower and the aircraft communicate, then the aircraft is almost visible. at approximately 10 kilometers ahead Therefore, I think the control tower will primarily look at it with the naked eye and then combine the information from the facilities detected by the radar and the bird detection response teams on the ground.

[Anchor]
However, at the time of the accident, there was a small number of bird control personnel and only one person, and some point out that an airport with such a large number of bird collision accidents should have been well prepared in the first place.

[Choi Ki-young]
As a result, it's a disappointing result. But if I don't think this is a bird migration that changes rapidly every year, then I think we need to look at what it was like in previous years. So, it is said that there were not many operations at the beginning of the opening of Muan Airport, but the number of operations has increased a lot this year.In previous years, there were similar bird migration patterns, and I think there would have been less manpower because the airport is used less frequently, but isn't dealing with such risks separate? So, even if the frequency of use is low, if there are many birds, there is a regret that we should have strengthened our countermeasures against birds.

[Anchor]
Bird collisions are not that uncommon in themselves, but is there any way to prevent the aircraft from being sucked into the engine itself, other than avoiding the birds or chasing them?

[Choi Ki-young]
Nothing for now. Since we can't control living things at our disposal, it's a priority to avoid those things first. So if you block the engine and install a screen, it reduces weight, resistance, or efficiency, and there are frequent bird collisions. It's not unusual for us, but that doesn't mean it happens routinely, so we deal with it when it happens, we deal with it when it's dangerous, we deal with it near the airport. It is not technically easy to attach any more special devices to an airplane.

[Anchor]
Now it's important to find out the cause. It will be important to find out the cause and take measures to prevent the same from happening in the future, but the black box has been collected and an investigation has been launched. Last evening, the National Transportation Safety Board and Boeing employees also arrived and will join the investigation in the future. It says it will take at least a month to decrypt the black box, what do you think should be focused on?

[Choi Ki-young]
Isn't it to know exactly what happened and what to do to prevent it, whether the pilot's actions were appropriate? Then the question of why didn't the landing gear come down, which everyone is curious about. The question of why they had to repeat it so urgently, these things, even though communication with the control center was cut off, the captain and the assistant manager had roles divided, so there must have been a lot of conversations. Then why did they make such decisions on such matters as emergency rehabilitation? What's based on that is the data that appeared on the dashboard that pilots saw at the time. As you know, there are two main black boxes, the voices of the pilot and co-pilot were recorded for about 30 minutes. The final 30 minutes. And then the plane is for tens of hours. Dozens of hours of plane record data that are slightly different for each model. There are data on engine conditions, various instruments, and important warnings, so I think it will be recorded to some extent how many hours the aircraft flew. So I think securing these things is a necessary factor in identifying the exact cause.

[Anchor]
I told you that it takes at least a month to detoxify, but since there are so many reasons to be estimated and there are many things to consider, how long will it take for us to find out more specific causes?

[Choi Ki-young]
We call it a black box, but it's functionally the same as a memory stick, to put it simply. I can print out the data first, but as I said earlier, rather than causing confusion by estimating it and releasing it. In addition to the black box, there will be other communication materials, CCTVs installed at Muan Airport, and other materials. incidental materials We put all those things together and we put the puzzle together. If the puzzle pieces are scattered now, it's because we want to take a variety of puzzles, put them together thoroughly, and then come up with one exact conclusion. It takes at least this much time to approach them numerically and draw a primary conclusion, and looking at the data itself is not that difficult.

[Anchor]
Due to the aircraft accident, there is a lot of psychological anxiety among the people about the plane. The same model as this disaster was returned beyond landing gear. So, the Ministry of Land, Infrastructure and Transport decided to inspect the Boeing 737-800, the model of the accident. What do you think you're going to look into?

[Choi Ki-young]
In the case of aircraft, major failures are supposed to be reported, and then there are things that are not reported and are done on their own. So, when it comes to warnings, there are some things that do not lead to direct problems such as accidents, and airlines are supposed to manage themselves with information. So, once again, airlines and a large number of 737-800s in Korea are operating, so the Ministry of Land, Infrastructure and Transport should work closely with each airline to focus on the problems that occurred in each airline and the situations in which all problems occur in common. Then, when unfortunate events that were unthinkable like this continue in succession. In fact, if we had known about these things in advance, wouldn't we have prepared a little better? Assuming this situation again, I think it will be an opportunity for airport authorities, airline maintenance, and even pilots to think about these things once again.

[Anchor]
It's also important to find out the cause as soon as possible.I think it's also important to be accurate. That's all for today's talk. I was with Choi Ki-young, a professor of aerospace at Inha University. Thank you.