It was confirmed on the 31st that Muan International Airport was criticized for failing to comply with the recommended standards for the runway end safety area while installing a localizer (landing guidance safety facility). A tragedy occurred at Muan Airport on the 28th when a Jeju Air passenger aircraft with 181 passengers on board collided with a localizer and an outer wall during landing, resulting in the death of 179 people.
According to the 'Muan International Airport Operation Rules' posted on the Korea Airports Corporation website on May 9, Muan Airport was pointed out by Korea Airports Corporation for failing to comply with the regulations of 'Article 76 of Airport Safety Operation Standards and Article 21 of Aerodrome Facility Installation Standards on the Runway End Safety Area.'
The Airport Operations Manual contains comprehensive information on airport operations, from site and facility information to safety management systems and restrictions. It also includes emergency operation plans, such as snow removal operation plans during snowfalls. The critique that the localizer installation point does not comply with recommended standards is listed under 'Restrictions' in the Airport Operations Manual.
According to these Airport Operations Manual, Muan Airport is required to establish a safety area up to 240 meters from the runway end. However, it installed the localizer 202 meters from the end in the 01 direction (normal direction, south to north) and 199 meters in the 19 direction (reverse, north to south). A localizer refers to an antenna-shaped facility installed around the airport runway, playing a role in guiding the aircraft to land in the center of the runway.
Regarding this, Korea Airports Corporation pointed out that the safety area is inadequate by 38 meters in the 01 direction and 41 meters in the 19 direction. The airport responded, "We will consider securing additional areas in the second phase expansion of Muan International Airport."
The distance between Muan Airport's localizer installation point (LLZ) and the end is relatively short compared to other airports. At Incheon International Airport, a leading domestic airport, the localizer is installed 295 meters (runways 1-3) and 298 meters (runway 4) away from the runway end. Other airports are also reported to have installed localizers about 240 meters behind the runway end according to the airport safety operation standards.
However, the aircraft that had the accident at Muan Airport passed the LLZ and also collided with an outer wall 323 meters from the runway end. Even if the airport had adhered to the standard and installed the localizer 240 meters back, it is likely the collision could not have been avoided.
Meanwhile, there are criticisms that the structural form of the localizer installed at Muan Airport did not comply with regulations. Article 24 of the Ministry of Land's notice 'Airport and Aerodrome Facility and Take-off and Landing Space Installation Standards' stipulates that 'the strength of the runway end safety area should reduce the risk of damage to aircraft landing before or overshooting the runway and help decelerate the aircraft and facilitate the movement of rescue and fire vehicles.'
The localizer installed at Muan Airport is embedded 30-40 cm deep in a mound with a height of 2-3 meters and protruding about 7 cm above the mound. Experts point out that this form does not comply with the notice's requirement to 'reduce the risk of damage to overshooting aircraft.'
In the case of Incheon Airport, the antenna is installed on a foundation structure that rises only 7.5 cm above the ground and is designed with a steel frame to prevent damage to the exterior of the aircraft in the event of a collision.
According to the 'Incheon Airport Localizer Antenna Installation Status' submitted by Incheon Airport to the office of lawmaker Yeom Tae-young of the Democratic Party of Korea, it explained, “Incheon Airport installed the localizer on a buried concrete base underground, not in a mound shape,” and noted, “The antenna is made of materials and structures designed to easily break or bend.”
An aviation industry official explained, “The form of the localizer installed at Incheon Airport is like a ‘crash prevention bump’ installed in parking lots,” and noted, “The protruding antenna is made of materials that can easily break or bend.”
Thanks to this structure, in 2016, when a UPS cargo plane overran the runway at Incheon Airport due to landing gear damage and collided with the localizer, there was almost no impact on the aircraft. At the time, the aircraft had five crew members on board, including one pilot, and all occupants evacuated to safety immediately after the accident.
An aviation industry official said, “The localizer installation rules can be considered common sense. If the structure is too hard or too high, it would damage the aircraft,” while adding, “Standards are set taking such factors into consideration.” The official further noted, “It seems that the structural form of Muan Airport's localizer did not comply with the related regulations.”