504th_Bombardment_Group

504th Bombardment Group

The 504th Bombardment Group (504th BG) was a World War II United States Army Air Forces combat organization. It was inactivated on 15 June 1946.

History

The unit served primarily in the Pacific Ocean theater of World War II as part of Twentieth Air Force. The 504th Bomb Group's aircraft engaged in very heavy bombardment B-29 Superfortress operations against Japan.

Operational units

393d Bombardment Squadron 1944
398th Bombardment Squadron 1943-1946
421st Bombardment Squadron 1943-1946
507th Bombardment Squadron 1944
680th Bombardment Squadron 1944-1946

Aircraft flown

Stations assigned

Dalhart AAF, Texas 11 Mar 1944
Fairmont AAF, Nebraska 12 Mar-5 Nov 1944
North Field, Tinian 23 Dec 1944
Clark Field, Luzon 6 Mar-15 Jun 1946

Operational history

The 504th Bombardment Group (Very Heavy) was constituted on 18 February 1944 and activated on activated on 11 March 1944 at Dalhart AAF, near Dallas, Texas. The group was initially equipped with B-17 Flying Fortresses due to a lack of B-29 Superfortress aircraft. The unit was then reassigned for advanced training and received B-29s at Fairmont AAF, Nebraska during the late spring and summer of 1944. While in training status, the 504th was reduced to two squadrons instead of the normal three allocated to B-29 groups. One of the original squadrons, the 393rd, was transferred out for a highly classified mission. It became the nucleus of the 509th Composite Group, the first and only military unit in history to drop a Atomic Bomb in combat.

After training, the unit was reassigned to the South West Pacific theatre in late in 1944 for service with the Twentieth Air Force. The 504th was assigned to the 313th Bombardment Wing on Tinian. The group began combat operations from Tinian in Jan 1945 with attacks on Japanese airfields and other installations on Maug and Iwo Jima and in the Truk Islands. Flew its first mission against the Japanese home islands early in Feb 1945 when the group bombed the industrial area of Kobe. Continued to attack strategic targets in Japan, operating in daylight and at high altitude to bomb such objectives as aircraft factories, chemical plants, harbors, and arsenals.

Received a Distinguished Unit Citation (DUC) for striking the industrial center at Yokohama late in May 1945. Began incendiary raids in Mar 1945, flying at night and at low altitude to strike area targets in Japan. Started mining operations against enemy shipping late in Mar, receiving a 2d DUC for mining Korean shipping lanes, the Shimonoseki Strait, and harbors of the Inland Sea, July-August 1945. In April and May 1945 the group hit airfields from which the Japanese launched kamikaze planes against the invasion force during the assault on Okinawa. During mid June 1945 the 680th Bomb Squadron joined the 504th bomb group bring them up to full strenght of 3 squardons.

After the war it dropped food and supplies to Allied prisoners, participated in show-of-force missions, and flew over Japan to evaluate damage inflicted by bombardment operations. Moved to the Philippines in March 1946. Inactivated at Clark Field on Luzon on 15 June 1946.

Historical note: The 504th Bombardment Group flew the last combat mission by the United States Army Air Forces of World War II, its last combat mission being on 15 August, 1945.