ReutersAviation experts have raised questions about an “unusual” concrete wall near the runway and its role in the South Korean plane crash that killed 179 people.
Footage shows the Jeju Air plane running off the runway before hitting the wall and bursting into flames at Muan International Airport.
Authorities investigating the cause of South Korea's worst-ever plane crash are examining the significance of the location of the concrete wall about 250 meters (820 feet) from the end of the runway.
Air safety expert David Learmont said that if the “obstacle” had not been present, the plane “would have stabilized with most – and perhaps all – of those on board still alive.”
The pilot reported that the plane collided with a bird, then canceled the original landing and requested permission to land from the opposite direction.
The plane fell some distance along the 2,800-meter runway and appeared to land without using its wheels or any other landing gear.
Mr. Lermont said the landing was “as good as a landing without flaps or without gears: the wings are level, the nose is not too high to avoid breaking the tail” and the plane did not suffer serious damage as it slid along the runway.
He added: “The reason behind the death of so many people was not the landing itself, but the fact that the plane collided with a very difficult obstacle directly behind the runway.”
Christian Beckert, a Lufthansa pilot based in Munich, described the concrete structure as “unusual” and told Reuters news agency: “Normally, in an airport with a runway at the end, there is no wall.”
The concrete structure holds a navigation system that helps planes land – known as a GPS locator – according to South Korea's Yonhap News Agency.
Yonhap reported that the 4-meter-high runway was covered with dirt and was raised to maintain the site level with the runway to ensure its proper operation.
South Korea's Ministry of Transport said other airports in the country and some abroad have the equipment installed with concrete structures. However, officials will examine whether it should be made of lighter materials that could break more easily on impact.
Chris Kingswood, a pilot with 48 years experience who flew the same type of plane involved in the crash, told BBC News: “Obstacles within a certain range and distance of the runway have to be breakable, which means that if the plane hits them they break.
“It seems unusual for it to be so rigid. The plane, I understand, was going very fast, and it landed a long way down the runway, so it will have come a long way past the end of the runway… so where do you draw the line with that? That's definitely something It will be investigated.
“Airplanes are not strong structures – they are, by design, lightweight to make them efficient in flight. They are not really designed to fly at high speed on their belly, so any type of structure can cause the fuselage to disintegrate and then break apart.” Disastrous.
“Fuel is kept in the wings, so once a wing explodes, the potential for a fire is high.
“So it is not a given that if the wall had not been there, the outcome would have been completely different.”
Kingswood said he would be “surprised if the airport does not meet all requirements according to industry standards.”
He added, “I think that if we were to tour the airports in many major international airports… we would find many obstacles that could similarly be accused of posing a danger.”
Aviation analyst Sally Gethin wondered whether the pilot knew the barrier was there, especially since the plane was approaching from the opposite direction to the usual landing path.
She told BBC News: “We want to know, did they (the pilots) know that there were these hard limits at the end?
“If they were directed by the control tower to change the use of the runway the second time, that should come out in the black boxes investigation.
“I think there are a lot of questions.”
