History of The United States Air Force - World War II

World War II

The Air Force came of age in World War II. President Franklin D. Roosevelt took the lead, calling for a vastly enlarged air force based on long-range strategic bombing. Organizationally it became largely independent in 1941, when the Army Air Corps became a part of the new U.S. Army Air Forces (AAF), and the GHQ Air Force was redesignated the subordinate Combat Command. In the major reorganization of the Army by War Department Circular 59, effective March 9, 1942, the newly created Army Air Forces gained equal voice with the Army and Navy on the Joint Chiefs of Staff and complete autonomy from the Army Ground Forces and the Services of Supply. The reorganization also eliminated both Combat Command and the Air Corps as organizations (the latter became a combat arm until 1947) in favor of a streamlined system of commands and numbered air forces for decentralized management of the burgeoning Army Air Forces.

The reorganization merged all aviation elements of the former air arm into the Army Air Forces. Although the Air Corps still legally existed as an Army branch, the position and Office of the Chief of the Air Corps was dissolved. However, people in and out of AAF who remembered the prewar designation often used the term "Air Corps" informally, as did the media.

Carl A. Spaatz took command of the Eighth Air Force in London in 1942; with General Ira Eaker he supervised the strategic bombing campaign. In late 1943, Spaatz was made commander of the new U.S. Strategic Air Forces, reporting directly to the Combined Chiefs of Staff. Spaatz began daylight bombing operations using the prewar doctrine of flying bombers in close formations, relying on their combined defensive firepower for protection from attacking enemy aircraft rather than supporting fighter escorts. The doctrine proved flawed when deep-penetration missions beyond the range of escort fighters were attempted, because German fighter planes overwhelmed U.S. formations, shooting down bombers in excess of "acceptable" loss rates, especially in combination with the vast number of flak anti-aircraft batteries defending Germany's major targets. American fliers took heavy casualties during raids on the oil refineries of Ploieşti, Romania, and the ball-bearing factories at Schweinfurt and Regensburg, Germany, and it was the loss rate in crews and not materiel that brought about a pullback from the strategic offensive in the autumn of 1943.

The Eighth Air Force had attempted to use both the P-47 and P-38 as escorts, but while the Thunderbolt was a capable dog-fighter it lacked the range, even with the addition of drop tanks to extend its range, and the Lightning proved mechanically unreliable in the frigid altitudes at which the missions were fought. Bomber protection was greatly improved after the introduction of North American P-51 Mustang fighters in Europe. With its built-in extended range and competitive or superior performance characteristics in comparison to all existing German piston-engined fighters, the Mustang was an immediately available solution to the crisis. In January 1944 the Eighth Air Force obtained priority in equipping its groups, so that ultimately 14 of its 15 groups fielded Mustangs. P-51 escorts began operations in February 1944 and increased their numbers rapidly, so that the Luftwaffe suffered increasing fighter losses in aerial engagements beginning with Big Week in early 1944. Allied fighters were also granted free rein in attacking German fighter airfields, both in pre-planned missions and while returning to base from escort duties, and the major Luftwaffe threat against Allied bombers was severely diminished by D-Day.

In the Pacific Theater of Operations, the AAF provided major tactical support under General George Kenney to Douglas MacArthur in the Southwest Pacific theater. Kenney's pilots invented the skip-bombing technique against Japanese ships. Kenney's forces claimed destruction of 11,900 Japanese planes and 1.7 million tons of shipping. The first development and sustained implementation of airlift by American air forces occurred between May 1942 and November 1945 as hundreds of transports flew more than half a million tons of supplies from India to China over the Hump.

The AAF created the Twentieth Air Force to employ long-range B-29 Superfortress bombers in strategic attacks on Japanese cities. The use of forward bases in China (needed to be able to reach Japan by the heavily laden B-29's) was ineffective because of the difficulty in logistically supporting the bases entirely by air from its main bases in India, and because of a persistent threat against the Chinese airfields by the Japanese army. After the Mariana Islands were captured in mid-1944, providing locations for air bases that could be supplied by sea, Arnold moved all B-29 operations there by April 1945 and made General Curtis LeMay his bomber commander (reporting directly to Arnold, who personally commanded Twentieth Air Force until July). LeMay reasoned that the Japanese economy, much of which was cottage industry in dense urban areas where manufacturing and assembly plants were also located, was particularly vulnerable to area attack, and abandoned inefficient high-altitude precision bombing in favor of low-level incendiary bombings, aimed at destroying large urban areas. Tokyo suffered a firestorm in which over 100,000 persons died. At the same time the B-29 was also employed in widespread mining of Japanese harbors and sea lanes. Neither Arnold and General Carl Spaatz wanted to use the atomic bomb, but were ordered by Secretary of War Henry Stimson and President Harry Truman to use the new weapon against Japan during the Atomic bombings of Hiroshima and Nagasaki in August 1945.