In a statement on its website, the Ministry described the flight as 10 hours long and controlled both by controllers on the ground and from an A-50U aircraft, the Russian version of the E-3 Sentry AWACS plane. The Ministry of Defense also said:
In the course of fulfilling the missions, the aircraft of both countries acted strictly in accordance with the provisions of international law. The airspace of foreign states was not violated.
The Russian and Chinese bombers entered South Korea’s ADIZ, an imaginary line sketched out by most countries over neighboring airspace. Aircraft that enter an ADIZ are looked at a little more rigorously by a country’s air force and are required to file flight plans that give advance notice. Foreign military aircraft that enter ADIZs are routinely intercepted by fighter jets.
In this case, the Republic of Korea Air Force scrambled F-15K “Slam Eagle” and F-16 fighter jets as a precautionary measure. The Chosun Ilbo reports a total of 19 Russian and Chinese aircraft flew near South Korea that day. South Korea’s Joint Chiefs of Staff say the Chinese pilots told Korean fighter pilots they were undertaking “routine training,” but the Russian aircraft “entered (the ADIZ) without prior notice.”
The flight, the Korean Joint Chiefs noted, was probably a response to recent U.S. bomber flights near China.
Last month, two U.S. Air Force B-1B Lancer bombers flew into China’s ADIZ in the East China Sea, and B-1Bs also flew into the South China Sea in early December. The B-1B is a heavy bomber, but it’s incapable of carrying nuclear weapons. In no instance did any of the bombers from Russia, China, or the U.S. enter the actual airspace of any other country.