The United States Army Air Forces activated Air Defense Command (ADC) in 1946, with a Numbered Air Force of the former Continental Air Forces, from which it took its mission of air warning and air defense. In September 1947, it became part of the newly established United States Air Force. The command become a subordinate organization of Continental Air Command (ConAC) on 1 December 1948. ConAC gradually assumed direct charge of ADC air defense components, and ADC inactivated on 1 July 1950. But five months later, on 10 November 1950, Generals Vandenberg and Twining notified General Whitehead that "the Air Force had approved activation of a separate Air Defense Command CONAC with headquarters on Ent" with the mission to stop a handful of conventionally armed piston engine-powered bombers on a one-way mission. The command was formally reactivated on 1 January 1951.