The 19th Bombardment Group transferred to active duty in September 1941. It was replaced by the AAC Ferrying Command Specialized Four Engine school. The school operated under the Army Air Corps Ferrying Command, which had been established in late May 1941 and charged with transporting aircraft overseas for delivery to the Royal Air Force. The students were training to ferry Consolidated B-24 Liberator bombers, (the aircraft used at the Four-Engine School) and other multi-engine aircraft to the RAF in Great Britain. TWA chose Albuquerque for the school's location because of its 10,000-foot runway, which could accommodate B-24s, as well as its fair weather. The students were trained in pilot skills, instrument flying, meteorology, radio, briefing, and general transition.