(and later FAA) General Surveillance Radar stations into a centralized center for Air Defense, intended to provide early warning and response for a Soviet nuclear attack. The 438th Fighter-Interceptor Squadron was upgraded again to the F-106 Delta Dart interceptor in June 1960, one of the first ADC squadrons to receive the new interceptor. In addition, the 507th Fighter Group was upgraded to the 507th Fighter Wing (Air Defense), which was established, and activated, on 28 December 1960. With the upgrade to wing level, the 507th Combat Support Group became the host unit at Kincheloe on 1 February 1961. The 507th Fighter Wing continued to employ F-106 aircraft at Kincheloe AFB until its inactivation on Sep. 30, 1968. Air Defense Command inactivated its interceptor facilities due to budgetary reasons caused by the cost of the Vietnam War. By the late 1960s, and with the development of Intercontinental Ballistic Missiles (ICBM), it was believed that the chance of a Soviet bomber attack on the United States was remote and the USAF began closing fighter-interceptor bases at the direction of the Secretary of Defense. The BOMARC missiles were inactivated four years later in 1972. As a result of the phase down, ADC moved the 438th Fighter Interceptor Squadron to Griffiss AFB, New York. With its inactivation, jurisdiction of Kincheloe AFB was transferred to Strategic Air Command on 1 October 1968. Strategic Air Command In the 1950s, the USAF adopted a policy of dispersing Strategic Air Command (SAC) bombers and tankers. At Kincheloe the runway was extended to 12,000 feet in 1958 to accommodate 15 B-52H bombers and ten KC-135 tankers. In addition to the runway, overruns of 1,000 feet (305 m) were constructed on both ends of the runway, along with 75-foot (23 m) shoulders on each side of the runway, providing a paved width of 300 feet (91 m). Along with the runway extension, a "Christmas tree" alert pad area was constructed on the north side of the runway end to accommodate alert aircraft, as well as a "Mole hole" crew living facility, where alert crews would live on shifts ready to man the alert aircraft and take off within a few minutes' notice. The original cost of the undertaking was estimated at $30 million. On 2 February 1959, SAC established the 4239th Strategic Wing at Kincheloe AFB, Michigan as part of SAC's plan to disperse its B-52 Stratofortress heavy bombers over