第21爆撃集団
Re-designated on 1 April 1944 as a B-29 Superfortress Very Heavy bombardment squadron. When training was completed moved to North Field Guam in the Mariana Islands of the Central Pacific Area in January 1945 and assigned to XXI Bomber Command, Twentieth Air Force. Its mission was the strategic bombardment of the Japanese Home Islands and the destruction of its war-making capability.