Activated as a Boeing B-29 Superfortress squadron in early 1944; trained under Second Air Force. Due to a shortage of B-29s, the squadron was initially equipped with former II Bomber Command Boeing B-17 Flying Fortresses previously used for training heavy bomber replacement personnel as engineering flaws were being worked out of the B-29. The squadron was then reassigned for advanced training and received B-29s at Fairmont Army Air Field, Nebraska during the late spring and summer of 1944.
In December 1944 reassigned as the only operational B-29 squadron to 509th Composite Group at Wendover Field, Utah in December. Aircraft were refitted to Silverplate configuration becoming atomic bomb capable under a highly classified program. Deployed to North Field in late May 1945, flying non-combat missions practicing atomic bomb delivery techniques. The squadron was the only unit in the world to ever carry out and deliver nuclear weapons in combat, which dropped the first atomic bomb on Hiroshima, Japan, on 6 August 1945, and the second atomic bomb on Nagasaki, Japan, on 9 August 1945. Reassigned to the United States in November 1945, it became part of Continental Air Forces. The unit was deployed to Kwajalein Atoll in 1946 to carry out Operation Crossroads atomic bomb tests on Bikini Atoll in July.
Strategic Air Command
Began upgrading to the new Boeing B-50 Superfortress, an advanced version of the B-29 in 1949. The B-50 gave the unit the capability to carry heavy loads of conventional weapons faster and farther as well as being designed for atomic bomb missions if necessary. Squadron deployed to SAC airfields in England, and also to Andersen Air Force Base, Guam on long-term deployments in the 1950s. By 1951, the emergence of the Soviet Mikoyan-Gurevich MiG-15 interceptor in the skies of North Korea signaled the end of the propeller-driven B-50 as a first-line strategic bomber. Received new, swept wing Boeing B-47 Stratojets in 1955 which were designed to carry nuclear weapons and to penetrate Soviet air defenses with its high operational ceiling and near supersonic speed. The squadron flew the B-47 for about a decade when by the mid-1960s it had become obsolescent and vulnerable to new Soviet air defenses. The squadron began to send its stratojets to AMARC at Davis-Monthan Air Force Base, Arizona for retirement in 1965. Was scheduled for inactivation however instead received Boeing B-52D Stratofortresses in 1965. It rotated aircraft and crews to Andersen Air Force Base, Guam in support of Southeast AsiaOperation Arc Light operations between 1966 and 1969. Not operational, Nov 1969–Jun 1971. Re-equipped with General Dynamics FB-111 nuclear capable medium bomber in 1970; operated until retirement in 1990. It was reactivated in 1993 as first operational Northrop Grumman B-2 Spirit stealth bomber squadron.
Operations and decorations
Combat operations: Combat in Western Pacific, 1 Jul – 14 Aug 1945. Only squadron trained for atomic warfare in World War II. Participated in atomic bomb tests on Bikini Atoll, Jul 1946, while deployed on Kwajalein. Rotated aircraft and crews to Andersen AFB, Guam, in support of Southeast Asia Operations, 1966–1969.
Decorations: Air Force Outstanding Unit Awards: Apr – 1 Oct 1968; 1 Jul 1977 – 30 Jun 1979; 1 Jul 1981 – 30 Jun 1982; 1 Jul 1982 – 30 Jun 1984; 1 Jul 1988 – 30 Jun 1990. Republic of Vietnam Gallantry Cross with Palm: 5 Mar – 14 Oct 1969.
Lineage
Constituted as the 393d Bombardment Squadron, Very Heavy on 28 February 1944
