Mouwembleem 3rd Air Force (Sleeve patch 3rd Air Force)

One of the four original numbered air forces, Third Air Force was activated as the Southeast Air District of the GHQ Air Force on 18 December 1940 (which became Air Force Combat Command on 20 June 1941), at MacDill Field, Florida. It was redesignated Third Air Force on 26 March 1941 with a mission for the defense of the Southeast and Gulf of Mexico regions of the United States.

World War II

Headquartered at MacDill Army Airfield, Florida during World War II, Third Air Force initially provided air defense for the southeastern United States (1940–1941) and flew antisubmarine patrols along coastal areas of the Atlantic Ocean and Gulf of Mexico from after Pearl Harbor. In January 1942, the command was withdrawn by Air Force Combat Command from the Eastern Defense Command and assigned operational training of units, crews, and replacements for medium bombardment, fighter, and reconnaissance operations.

In 1942, the antisubmarine patrols were turned over to the Coast Guard and other agencies and the command was engaged primarily in training replacements for combat units and operational training of units, crews, and individuals for bombardment, fighter, and reconnaissance operations. It received graduates of Army Air Forces Training Command flight schools; navigator training; flexible gunnery schools and various technical schools, organized them into combat groups and squadrons, and provided operational unit training (OTU) and replacement training (RTU) to prepare groups and replacements for deployment overseas to combat theaters. Third Air Force primarily trained B-25 Mitchell and B-26 Marauder medium bomber groups and A-20 Havoc andA-36 Apache light bomber groups. It also trained replacement fighter pilots, initially using P-39 Aircobra and P-40 Warhawks in 1942, later with P-47 Thunderbolts and P-51 Mustangs beginning in 1943 and 1944 as they became available. Third Air Force also provided support to the Army Air Forces School of Applied Tactics in Florida. By 1944, most of the Operational Training of groups ended, with the command concentrating on RTU training using Army Air Force Base Units (AAFBU) as training organizations at the airfields controlled by Third Air Force.

Also by 1944, the majority of the Numbered Air Forces of the AAF were fighting in various parts of the world, such as the Eighth Air Force in Europe and the Twentieth Air Force in the Pacific. They were supported by four numbered air forces located within the United States (known as the Zone of the Interior, or "ZI".) On 13 December 1944, First, Second, Third and Fourth Air Force were all were placed under the unified command of the Continental Air Forces, the predecessor of the later established Strategic Air Command, Tactical Air Command, and Air Defense Command, which were all established in 1946.