On Tuesday, a Chinese People’s Liberation Army Air Force (PLAAF) fighter entered South Korea’s air defense identification zone (Korea-ADIZ, or KADIZ) for more than four hours without notifying South Korean authorities.
According to the Korea Herald, citing the South Korean Joint Chiefs of Staff, the aircraft “came close to South Korean territory, prompting the [Republic of Korea] Air Force to scramble fighter jets to monitor its activity.”
The ROKAF scrambled more than 10 aircraft to intercept the PLAAF fighter, including F-15K Slam Eagles and KF-16s.
According to the South Korean Joint Chiefs, the Chinese fighter entered South Korea’s ADIZ at 9:34 am local time on Tuesday and approached South Korean territory northwest of Ulleungdo in the Sea of Japan, coming as close as 55.5 kilometers to South Korean territory.
After receiving warnings from the South Korean military, the Chinese fighter left the area at 2:01 pm. The Chinese fighter’s trajectory required it to transit the Tsushima strait, which separates Japan from the Korean Peninsula.
“Our military warned it to stop the act of raising tensions that can trigger an accidental conflict through the South Korea-China [military] hotline and [pilot’s] radio communication,” the South Korean Joint Chiefs noted, describing the Chinese fighter’s flight path as “unsual.”
Chinese fighters have previously violated South Korea’s ADIZ, but have usually done so on the western side of the Korean Peninsula or in the northern reaches of the East China Sea.
The South Korean Joint Chiefs noted that Tuesday’s flight was unprecedented, in that it marked the first time a Chinese fighter had come so close to South Korean territory on the eastern side of the Peninsula, above the Sea of Japan.
China’s self-declared air defense identification zone, which was announced in 2013, partially overlaps with South Korea’s in the East China Sea over Ieodo, a disputed submerged rock between the two countries.
ADIZs are not considered sovereign or territorial air space and are unilaterally declared by states to monitor activity by foreign aircraft during an approach toward their territorial airspace.
Tuesday’s incident comes amid generally improved bilateral ties between South Korea and China after both countries reached an agreement to set aside a long-simmering bilateral dispute over Seoul’s acceptance of a U.S. missile defense system — the Terminal High Altitude Area Defense (THAAD) system — on its territory in 2017.