Pursuit Group at Wheeler Field. Commanding a pursuit group involved a considerable change of pace for a man whose career thus far had been spent in bombers. His adjutant, First Lieutenant Bruce K. Holloway felt that Walker never demonstrated the "emotional exhilaration toward flying a high performance machine that is so typical of fighter pilots." Nor did he warm to the Curtiss P-36 Hawk fighter, especially after a near-fatal accident. World War II Air War Plans Division Walker returned to the United States in January 1941 and joined the Air War Plans Division in the Office of the Chief of the United States Army Air Corps in Washington, D.C., as an assistant chief of staff. Brigadier General Carl Andrew Spaatz was head of the division. Lieutenant Colonels Olds and Muir S. Fairchild, old colleagues of Walker's from the Air Corps Tactical School, were two of Spaatz' assistants. Walker was promoted to temporary lieutenant colonel on 15 July 1941. In the June 1941 reorganization of the Air Corps, Spaatz became chief of staff to the Commanding General, United States Army Air Forces, Major General Henry H. Arnold, who appointed Colonel Harold L. George, a former student of Walker at the Air Corps Tactical School from 1931 to 1932, to replace Spaatz as head of the Air War Plans Division. Walker joined George's planning team, along with Majors Haywood S. Hansell and Laurence S. Kuter. All were former instructors at the Air Corps Tactical School and members of the "Bomber Mafia". The Air War Plans Division was tasked with developing a production requirements plan for President Franklin D. Roosevelt, who wanted it by 10 September 1941. In just nine days in August 1941, George, Olds, Fairchild, Walker, Kuter and Hansell drafted the AWPD-1 plan for a war against Germany. Reflecting their belief in bombardment as the principal form of aviation, the plan was based upon the number of bombers that they estimated would be required to knock out Germany's key industries – electric power, transportation and petroleum. In order to neutralize anticipated opposition from the German Air Force, they planned for bombing aircraft factories and the sources of the light metals needed for aircraft production. These targets were collated along with the estimated tonnage of bombs required to destroy them. The plan called for a bomber force of 98 medium, heavy and very heavy bomber groups, totaling 6,834 aircraft. Sixteen fighter groups