Airport design caused controversy during the Jeju Air tragedy

A Jeju Air plane carrying 181 people on December 29 seemed to hit a bird, had landing gear problems and had to land on its belly at Muan Airport in South Jeolla Province. The Boeing 737-800 could not decelerate, rushed off the runway and crashed into the concrete wall at the end of the runway, breaking into many pieces and burning fiercely, killing 179 people.

On January 2, Korean police deployed forces to search the Muan airport operating unit, looking for records and data related to flight operations. Investigators are also looking into communications between air traffic control and the plane, as well as the reasonableness of the concrete walls that house the landing support system (ILS) at both ends of the runway.

The investigation with Muan airport management was conducted after Korean public opinion criticized the design of this airport facility, pointing out limitations such as no landing buffer zone outside the runway to minimize casualties. in accident. The fact that the structure housing the ILS system was solidly built with a height of more than 2 meters and reinforced with earthen mounds caused it to be called the “wall of death” during the tragedy.

Investigators are looking at the design of Muan airport as part of the reason why so many people died in the incident. The structures at Muan airport are not uncommon at airports around the world, but they have their own standards in terms of location and materials.

Aviation safety experts believe that the concrete wall contributed to making the accident more deadly, because if it had not crashed into it and had more space, the Jeju Air plane could have continued to slide, crashing into the surrounding steel mesh wall. airport, then safely stopped in an open field nearby.

“The plane landed almost perfectly on its belly and was fine until it hit the wall,” John Cox, a former Boeing 737 pilot, now an aviation safety expert, told WSJ. “That architecture certainly made the accident more serious.”

A Muan airport official said on December 30 that the concrete wall will be built in 2023, during the process of Muan airport replacing the old ILS system. This person added that the ground at the end of the runway sloped down, so they had to build a large mound and build a 2m high concrete wall on top of it. With this design, the ILS system and support platform have an overall height of about 4 m.

“Investigators will evaluate that wall,” said Hassan Shahidi, president of the non-profit aviation safety consulting organization Flight Safety Foundation.

Mr Shahidi said barriers near the runway “must be easily breached in the event of an ejection so that the impact from a collision is not catastrophic”. “What we saw in Muan was the plane crashing into a very thick concrete wall,” he added.

The Korean Ministry of Land, Infrastructure and Transport (MOLIT) stipulates that airports in this country must have a safety zone at least 90 m long from the end of the runway. All structures in this area must be built from lightweight materials that are easily broken upon impact. Muan airport safety zone is nearly 200 m long, the concrete wall is more than 50 m from the end of the safety zone.

According to Korean standards, the concrete wall was built outside the safe zone and did not violate any regulations. But this is what makes aviation experts worried, because the Jeju Air tragedy has shown that that safety zone is too short.

At most major commercial airports in the US, the runway end safety zone is usually 300 meters long and more than 150 meters wide, according to the Federal Aviation Administration (FAA). The International Civil Aviation Organization (ICAO) recommends that standard buffer zones should be between 180 m and 300 m long.

However, determining whether the safety area at the airport meets the requirements depends on many factors, such as geographical location. Some runways were built before buffer zone regulations were in place.

The 2020 edition of the Muan Airport Operations Manual also noted the location of the wall in the ILS system being too close to the runway, recommending a review during the planned airport expansion, Korea Herald reported.

The investigation also discovered that information about the concrete wall, such as thickness and height, was not mentioned in the Notice to Aeronautics (NOTAM). NOTAMs are used to warn pilots of potential hazards, such as obstacles or changes in airport infrastructure.

At space-limited airports like New York’s LaGuardia, officials also arrange a barrier called an “engineered material deceleration system (EMAS)” to stop aircraft from flying off the runway without causing damage. great harm. EMAS consists of many porous concrete panels arranged close together on a flat surface, which will break under the weight of the aircraft, causing the aircraft’s wheels to sink and help reduce speed quickly.

In October 2016, the plane carrying then US Vice President-elect Mike Pence crashed off the runway at LaGuardia Airport, but everyone on board was safe thanks to the EMAS system.

“Without EMAS, runways must have clear safety zones,” according to Jeff Guzzetti, founder of safety consultancy Guzzetti Aviation.

The accident also sparked debate about whether the Jeju Air pilot had any other landing options that could have minimized the damage. Muan Airport has only one runway 2,800 m long, with two calls “01” if landing in the north direction and “19” if landing in the south direction.

During the runway expansion from October 2024, the usable length of runway “19” in the south direction is reduced to 2,500 m. In the opposite direction, the length of runway “01” is 2,800 m, including 300 m of stopway.

The plane initially landed in a northerly direction but failed, apparently due to a bird strike. After announcing the emergency, the pilot aborted the landing, regained altitude and then circled back. During the second landing attempt, the pilot chose to land in a southerly direction, at the beginning of runway “19”.

Experts say that if the pilot lands in the north direction, a 300 m stopway can help the plane decelerate further and reduce damage. In addition, the southbound end of the runway has an ILS concrete wall, while on the northbound side, this structure has been removed to serve the runway extension project.

MOLIT announced that it has requested a comprehensive inspection of infrastructure at 17 airports in Korea. This process will evaluate construction standards, materials used and the location of structures relative to the runway, especially factors that can threaten flight safety.

According to Korean daily newspaper Maeil Business Newspapersome airports such as Yeosu, Gwangju and Pohang Gyeongju also have concrete structures similar to Muan airport. The mound at Yeosu airport is even twice as high as that at Muan airport.

MOLIT Deputy Minister in charge of civil aviation Joo Jong-wan said officials still maintain the same opinion as before, that the wall built at the end of the runway complies with industry standards.

“However, we will comprehensively gather other regulations, such as from ICAO, and re-announce our position,” Mr. Joo said.