The 3rd Bomb Wing consisting of the 8th, 13th and 90th Bomb Squadrons flew the B-26 Invader bomber during the war, remaining at Kunsan from August 1951 until October 1954. A Marine aviation squadron, VMF(N)-513, arrived in April 1952, and a few months later the base added the 474th Fighter-Bomber Group, which included three squadrons of F-84 fighters, bringing the total size of the operation to one wing, one group, and a Marine fighter squadron. The 474th bombed and strafed such targets as bunkers, troops, artillery positions, bridges, vehicles, airfields, and power plants, and sometimes escorted bombers that attacked munitions factories and other objectives. In April 1953, the 474th Fighter-Bomber Group returned to the United States and was replaced by the 49th Fighter-Bomber Wing, also flying the F-84. During the Korean War, the large number of locations used for bases and the similarity of some geographical names prompted the Air Force to use alphanumeric identifiers for bases in addition to their proper designations. Under this system, each base in Korea received a "K number," simplifying positive identification when referring to the various bases. Kunsan received the number K-8, while Osan Air Base was also known as K-55. After hostilities ceased, the base began to draw down. The F-84 forces of the 49th Fighter-Bomber Wing left in November 1953, and by October 1954 the host unit of the base, the 3d Bombardment Wing, also departed. This left the base with a much-reduced mission. From 1953 to 1954, the 808th and 841st Engineering Aviation Battalions constructed what is today's main runway. For the next several years Kunsan merely hosted periodic rotations of fighter and light bomber squadrons, with base facilities maintained and operated by an air base group. During 1957 and 1958 the base hosted squadrons from Japan temporarily. During 1957–8 a Republic of Korea Air Force (ROKAF) F-86 Sabre crashed into the Yellow Sea south of the base after having a flame out and a USAF F-100 Super Sabre crashed in the rice paddies north of the base. The base remained a radar site as a back up during this time to Osan, until the Radar site was turned over to the ROKAF in mid 1958. The Osan detachment on the base also maintained a radio relay site from a hill on the base.