From 1941 on, United States aircraft production was much greater than the combined output of Japan and Germany, and the force of 3,305 combat planes in December 1941 grew to 41,000 in August 1945 [REF].
In early 1939, a combination of Army Air Forces tactical staff under General Arnold and Materiel Division engineers under then-Lieutenant Colonel Echols, prescribed the military requirements around which the B-29 Superfortress was to be built.