Authorities investigate causes behind deadly Jeju Air crash

Typically, localizers are designed to be "frangible," collapsing easily upon impact to reduce damage to aircraft. Investigators are looking into why this particular structure was built so close to the runway and if it adhered to regulations. The area beyond runways, known as the runway end safety area (RESA), should be free of rigid structures; however, Muan Airport's localizer was constructed with concrete supported by dirt embankments.

South Korea's transport ministry has stated that the structure complied with regulations since it was outside Muan Airport's designated 199-meter RESA. Experts suggest revisiting aviation regulations after this accident. While international guidelines recommend a minimum RESA length of 90 meters—with at least 240 meters advised—many question why an engineered materials arrestor system (EMAS) wasn't installed to decelerate overrunning aircraft.

Hwang Ho-won from Korea Aerospace University explained that EMAS beds can significantly enhance safety by slowing down aircraft during overruns or aborted takeoffs.

Muan International Airport’s operations manual had previously flagged concerns about the localizer’s proximity to the runway and called for a review amid planned expansions. The transport ministry has now ordered reviews across all 17 airports in South Korea for potential safety hazards.

Meanwhile, data from one of the aircraft’s black boxes—the cockpit voice recorder (CVR)—has been successfully converted into an audio file by South Korea’s Aviation and Railway Accident Investigation Board. This will aid investigators in understanding pilot actions before the crash. The flight data recorder (FDR), damaged in the crash and missing a key component, has been sent to the United States for analysis in hopes of extracting its data.