Members of the police special forces inspect the site of a Jeju Air plane crash at Muan International Airport, South Jeolla Province, Tuesday. Yonhap

The Ministry of Land, Infrastructure, and Transport (MOLIT) reiterated on Tuesday that the controversial localizer and its concrete foundation at Muan International Airport, linked to the severity of casualties in the Jeju Air flight 7C2216 crash, were constructed in accordance with regulations.

The design firm responsible for adding a concrete slab beneath the localizer also asserted that there was no violation of any safety guidelines.

At a press briefing on Tuesday, officials reaffirmed that the localizer was "constructed in accordance with regulations," despite criticism from domestic and international experts that its structure contributed to the high number of casualties.

The Dec. 29 crash saw the aircraft successfully execute a belly landing, only to overshoot the runway and collide with a 2-meter-high localizer embankment, resulting in an explosion that claimed 179 lives. The embankment, supported by 19 concrete pillars, has been cited as a critical factor in exacerbating casualties.

The controversy centers on the interpretation of the guidelines. Under the "Standards for Airport and Airfield Facilities and Runway Installation," the runway end safety area (RESA) must extend at least 90 meters beyond the runway end, with a recommendation to expand it up to 240 meters where feasible.

Some argued that the guideline mandates extending the RESA to include the localizer, while others interpreted it as requiring extension only up to the localizer.

The ministry explained that its review concluded the requirement to extend the runway end safety area (RESA) "up to" the localizer, as stipulated in the installation standards, aligns with International Civil Aviation Organization (ICAO) regulations.

Joo Jong-wan, head of the ministry's aviation policy division, said, "It is reasonable to interpret that obstacles must be removed within the runway end safety area (RESA), and that the RESA should be secured up to the localizer facility."

He added that Muan Airport's RESA, extending 199 meters to the localizer, exceeds the mandatory 90-meter minimum and complies with current guidelines.

In contrast, Federal Aviation Administration (FAA) regulations in the United States specify that localizer facilities should be located "beyond" the RESA, according to the ministry.

The second engine retrieved from the localizer at Muan International Airport is loaded onto a trailer for relocation on the seventh day after the crash, Thursday. Yonhap

Concrete pillars compliant but raise safety concerns

Addressing criticisms over the use of robust materials in the embankment, Joo said, "There are no domestic or international regulations governing the materials or design of facilities outside the RESA." He emphasized that the localizer's construction does not violate any existing standards.

However, he acknowledged shortcomings, saying, "Regardless of regulatory compliance, greater emphasis should have been placed on ensuring maximum safety."

The localizer embankment, built 264 meters from the runway end, was constructed during Muan Airport's opening in 2007. It features 19 concrete pillars, each 3 meters high and 0.26 meters wide, beneath an earthen embankment approximately 1.5 meters thick.

The design for the structure was initiated between 1997 and 1999 under the management of the Busan Regional Office of Aviation. From January 2000 to December 2007, during the construction phase, oversight was transferred to the Seoul Regional Office of Aviation.

In a renovation project last year, a concrete slab measuring 30 centimeters in thickness, 42 meters in length, and 3.4 meters in width was added atop the embankment.

Commissioned by the Korea Airports Corporation, the design phase for this project occurred between May and August 2020, with construction taking place from September 2023 to February 2024.

The renovation involved trimming 30 centimeters off the top of the existing 19 concrete pillars, filling the area with 40 centimeters of soil, and then placing the slab on top.

Following the upgrade, the exposed height of the installation above the embankment now stands at 70 centimeters.

Conflicting regulations

The ministry announced plans to revise conflicting regulations between the "Standards for Airport and Airfield Facilities and Runway Installation" (installation standards) and the "Standards for Airport Safety Operations" (operational standards).

While the installation standards do not restrict the materials used for facilities located outside the RESA, the operational standards state that navigational aids within 240 meters should be made of "breakable facilities and equipment" and installed "as low as possible."

Joo said, "The operational standards have been in effect since 2010, meaning they did not apply during Muan Airport's construction. However, the need to improve airport facilities to align with these standards during operation and management has been raised, and we will swiftly review this matter to ensure safety."

He added, "As there are inconsistencies between the construction and operational standards introduced alongside international guidelines, we plan to harmonize these regulations moving forward."

Police and firefighters conduct search operations at the site of a Jeju Air plane crash at Muan International Airport, South Jeolla Province, Tuesday, the 10th day since the accident. Yonhap

Bird strike confirmed

The government officially confirmed that a bird strike occurred during the Jeju Air flight crash.

According to the Aviation and Railway Accident Investigation Board, feathers were found in one of the aircraft's engines. However, whether both engines failed during the accident remains under investigation.

Lee Seung-yeol, head of the accident investigation board, said, "One engine clearly shows evidence of a bird strike. However, we need to investigate further to determine whether both engines were affected or if the other engine experienced less severe damage."

He added, "Even if a bird strike is severe, it does not immediately cause the engine to shut down."

As evidence of the bird strike, Lee said, "During the process of removing soil from the engine, we found some feathers." He said that the investigation would examine the engine's interior to identify the bird species and determine how it entered the engine.

Meanwhile, the investigation into the accident is expected to take a significant amount of time. As of Jan. 7, the investigation board has begun collaborating with the U.S. National Transportation Safety Board (NTSB) to retrieve data from the flight data recorder (FDR).

All but two people on the Jeju Air Boeing 737-800 plane carrying 181 died after it crashed at Muan International Airport on Dec. 29.

Transport Minister Park Sang-woo bows after a briefing on the Jeju Air crash at the Government Complex Sejong, Tuesday. Yonhap

This article from the Hankook Ilbo, a sister publication of The Korea Times, is translated by a generative AI and edited by The Korea Times.