Why was there a wall next to the runway?

Aviation experts have raised questions about an “unusual” concrete wall near the runway and its role in the South Korean airliner crash that killed 179 people.

Footage shows a Jeju Air plane skidding off the runway before crashing into a wall and bursting into flames at Muan International Airport.

Authorities investigating the cause of South Korea’s worst plane crash are considering the importance of a concrete wall about 250m (820ft) from the end of the road.

Air safety expert David Learmount said that if the “disruption” had not occurred, the plane “would have made it to rest with most – possibly all – of those on board alive”.

The pilot reported that the plane had hit a bird and he withdrew the first place he had landed and asked for permission to land on the other side.

The aircraft descended for a long distance near the 2,800m runway and appeared to land without using its wheels or other landing gear.

Mr Learmount said the landing was “as good as a flapless/gearless touch: wings level, nose not too high to avoid breaking the tail” and the plane suffered no major damage as it skidded down the runway.

“The reason why so many people died was not because of landing like that, but because the plane collided with a heavy obstacle on the other side of the road,” he said.

Christian Beckert, a Lufthansa pilot based in Munich, called the concrete structure “unusual”, telling Reuters: “Normally, in an airport with a runway at the end, you don’t have a wall.”

The concrete structure houses a navigation system that helps the aircraft land – known as a navigation system – according to South Korea’s Yonhap News Agency.

At 4m high, it was covered in dirt and raised to maintain the level of the area and the runway to ensure it works properly, Yonhap reported.

The Ministry of Transport in South Korea said that some airports in the country and some overseas have machines installed in concrete. However, officials will check whether they should have been made of lighter materials that will break easily in a collision.

Chris Kingswood, a 48-year-old pilot who flew the same type of aircraft involved in the crash, told BBC News: “Obstacles within a certain distance of the runway need to be easy, that is when the plane is moving. beating them for breaking in.

“It seems unusual for something to be that strong. The plane, as I understand it, was traveling at high speed, it was going a long way down the runway, so it would have gone a long way to the end of the runway… so where do you draw the line with that?

“Airplanes are not rigid structures – by design, they’re easy to make flyable. They’re not really designed to go very fast on their belly so any kind of structure can cause the fuselage to come apart and it’s a disaster.

“Fuel is stored in the wings so when the wing explodes, then firepower is important.

“So it goes without saying that if the wall hadn’t been there, it would have been a completely different outcome.”

Mr Kingswood said he would be “surprised if the airport did not meet all requirements in line with industry standards”.

“I suspect that if we go around the airfields at the major international airports… we will find many obstacles that can be equally accused of introducing risks,” he added.

Aviation analyst Sally Gethin questioned whether the pilot knew the obstacle was there, especially if the plane was coming from the opposite direction on the normal approach.

He told BBC News: “We need to know, did (the pilots) know there was this hard edge at the end?

“If they were ordered by the control tower to postpone the use of the runway for the second time, that should come from the investigation of the black boxes.

“I think there are a lot of questions.”