Constituted as 509th Composite Group on 9 Dec 1944 and activated on 17 Dec. Became the first AAF group to be organized, equipped, and trained for atomic warfare. Moved to Tinian, Apr-Jun 1945. Assigned to Twentieth AF. Flew practice missions in Jun and Jul. On 6 Aug 194 one of the group's B-29's, the "Enola Gay," piloted by the group commander Col Paul W Tibbets Jr, dropped an atomic bomb on Hiroshima, Japan. Three days later a B-29, "Bock's Car," piloted by Maj Charles W Sweeney, dropped an atomic bomb on Nagasaki. These two bombs, the first atomic weapons ever employed, quickly brought the war to an end. The group returned to the US, Oct-Nov 1945. Assigned to Strategic Air Command on 21 Mar 1946, providing the nucleus for the command's atomic striking force. Redesignated 509th Bombardment Group (Very Heavy) in Jul 1946. Participated in atomic tests (Operation Crossroads) in the Marshall Islands in 1946. Redesignated 509th Bombardment Group (Medium) in Jul 1948. Converted from B-29 to B-50 aircraft, 1949-1950. Inactivated on 16 Jun 1952.
Squadrons. 320th Troop Carrier: 1944-1946. 393d Bombardment: 1944-1952. 715th: 1946-1952. 830th: 1946-1952.
Stations. Wendover Field, Utah, 17 Dec 1944-26 Apr 1945; North Field, Tinian, 29 May-17 Oct 1945; Roswell AAFld, NM, 6 Nov 1945-16 Jun 1952.
Commanders. Col Paul W Tibbets Jr, 17 Dec 1944; Col William H Blanchard, 22 Jan 1946; Col John D Ryan, 15 Sep 1948; Col William H Blanchard, 21 Jul 1951-16 Jun 1952.
Campaigns. Air Offensive, Japan; Eastern Mandates; Western Pacific.
Insigne. Shield: Or, in base a label of three points gules, surmounted by an atomic cloud proper, between a pair of wings conjoined in base azure. Crest: On a wreath of the colors, or and azure, an atomic cloud or, with broken pattern gules, between two lightning bolts gules. Motto: Defensor Vindex - Defender Avenger. (Approved 10 Jul 1952.)
Data from Air Force Combat Units of World War II By Maurer, Maurer, Published 1986