Transcript of What videos of the Jeju Air jet can tell us about the plane crash in South Korea

We begin with breaking news. A fiery plane crashed in South Korea, killing 179 people, leaving just two survivors. Witness video shows the moment the Juju airjet skidded across the runway earlier today, unable to stop itself exploded at the end of the runway, killing nearly everyone on board. Witness is describing the chaotic moments.

I think it was about 9:00 or 8:50 AM. I heard a bang. At first, I thought it was an oil tanker accident, as we can see a lot of oil tankers nearby. Then I felt different. So I went outside and I saw a big dark smoke. Then I could hear a big explosion sound, not the one from the crash itself. Then I heard more explosion at least seven times.

Now, before the crash, a passenger sent this text message to a friend. Wait a minute, we can't land because a bird or birds caught in our wing. Since when, the friend says. Just now. Should I leave my last words? The passenger responds. Meantime, the two survivors, both crew members, are now in the hospital, and officials there are saying that one is now conscious and speaking with officials. The National Transportation Safety Board now is saying that it is sending its leading team of investigators to assist in the case. Cnn's Mike Valerio has more from Seoul.

The cataclysmic scene, stunning South Korea, a Jujuer Boeing 737, 800 with 181 people aboard The plane's landing gear, local officials saying, likely failed. The aircraft's belly scraping the pavement, coming down close to the end of the runway before crashing into an embankment and exploding. A breathtaking plume of smoke seen for hours. In its wake, hundreds of mourners, families of the dead, crowding into the arrivals hall at South Korea's Muan International Airport. The man in the white helmet, tasked with naming those who would never come home. Their bodies identified with loss and unspoken fairwells, too much for families to bear. I'm going crazy, a man shouts, shattered by the calamity. According to South Korean officials, on Sunday, 8:57 AM, local time, the flight arriving from Bangkok, Thailand, was contacted by the Muan Airport Control Tower. An air traffic controller, warning of birds near the runway, and a danger of potential bird strikes. Two minutes later, at 08:59 AM, the pilot makes a mayday call, and at 08:03 AM, the plane crashes.

One thing that's very perplexing is the reports that are coming in that the aircraft landed without the undercarriage deployed. Now, whether or not, it's a little bit unclear whether or not the undercarriage collapsed on landing or whether the undercarriage was not deployed at all.

Two crew members miraculously survived. They were both sitting in the back of the 737, 800 near the tail of the aircraft. Authorities hope the survivors can shed light on what happened. The voice inflate data recorder also recovered. Now, for our country that has been through so much with martial law declared earlier this month, this catastrophe has certainly cast a new Paul over South Korea, adding to the urgency to find out just how this could have happened. Mike Valerio, CNN, possible.

Just how this could have happened is certainly the question, and a lot to discuss. Let me bring in now my colleague, CNN's Richard Quest. Richard, good to have you. You have obviously covered your fair share of plane crashes over the years. I'm curious what your first questions are, obviously early days in terms of the investigation, but what are your first questions about what may have happened here?

This is one of the most perplexing accidents. If you read the various for her from experts, everyone is puzzled because we don't know. We have got a general idea of the sequence of events from that press conference. We know that the plane attempted to land, went past, called the mayday, then came back. But What we don't know is where the bird strike happened, how badly it hit the aircraft, clearly catastrophically, because it was unable to deploy the various things like landing gear, flaps, stress deploy, thrust deploys, thrust reverses, and the like. We don't know the exact sequence and the consequence of the various actions that took place. Why is that significant? Because if you look at the video of the plane when it finally does come in to land. Number one, the landing gear has not been deployed. It's not sheared off, the doors aren't open, it's not there. Secondly, it's I believe the flaps haven't been deployed, the thrust reversers haven't been deployed. It looks like the plane is landing way too fast, even in those circumstances. It touches down on the runway very far and very late into the runway. Therefore, we can say that whatever the pilots were grappling with was in extremis.

They were dealing with the most serious aspects of loss of control that barely... And they have this video, but there you go. Now, that video is believed to be showing the moment of Bird Strike. If you look at that, the plane is at a height sufficient enough where the wheels aren't down yet, so they haven't deployed the gear. Were they unable to do so? Were they basically sidetracked? Were they obsessed with what they were dealing with? We just don't know at the moment.

Yeah, I mean, to that point, Richard, as you mentioned the landing gear, we've heard a few possible causes floated. One, that there was a landing gear malfunction. Two, that it was the bird strike. Three, that bad weather may have played a part. From your perspective, what's the likelihood that perhaps it was all three or a combination of the three?

No, it doesn't look like there's any bad weather there. I wouldn't put necessarily bad weather in its clear blue skies, as you can see. The bird strike could certainly have so affected the performance of the engines that it had degraded the hydraulic capability of the 737. But this aircraft, you can also lower the landing gear by gravity. There's a lever you pull up and the thing falls down. That hadn't happened. Now, this is entirely possible because the pilots are overwhelmed in the moment. The pilots are dealing with just trying to keep this thing in the air, seeing the runway. Remember, they've been vected, so they were heading towards the runway. They They can see the runway. Their goal is just to get the plane on the ground as best they can. We just don't know what... We will find out because... Look, this is, by the way, one of the... This is an old one. I just brought this in to give you an idea of the thing that we talk about. When we talk about the black boxes, this is what we're talking about. This is actually quite an old one. But it gives you an idea of the thing.

There are two of them on board the aircraft. There's the cockpit voice recorder and the cockpit data recorder. Now, both of those have been recovered. South Korea is an extremely sophisticated and advanced country, and we'll be able to read them along maybe with help from others, but it will certainly be able to do it That will tell us what happened on the plane, what flight instruments were degraded to the point of being abandoned, what the pilots were saying to each other, and we will find out exactly what happened in this crash.

Yeah. Then in addition to the black boxes, Richard, we know that two people miraculously survived this, and they were crew members. Their understanding of what would have been happening, perhaps more sophisticated than just a passenger, how helpful will that be?

It will be helpful because they will be able to... They will have known what area of flight the plane was in. They will have known what the captain may have said in the cabin. They will be able to give an idea of just how it felt. Look, it's awful to be discussing this, Rahel. But that message, that message that was sent from one passenger to the ground. Now, obviously, an announcement had been made that there had been a bird strike, that the plane was now seriously degraded in its control capabilities. Then you take that and you add on to it what the flight data will tell us. I can tell you that the circumstances and the sequence of events here and the complexity of those events is way up there. This is one of those that we'll find out what happened. My guess is that it's going to be the pilots did a bloody good job in very difficult circumstances.

Yeah, complicated indeed. To that end, Richard Quist, we appreciate your expertise as we try to understand exactly what happened. That's Richard Quist. Thank you. Thank you.