509th Composite Group-Bringers of the Atomic Age

The 509th Composite Group was formed on December 17, 1944. The group was formed with the sole purpose of dropping the Atomic Bomb.



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Insignia of the 509th Composite Group during its 1946 assignment to the 58th Bombardment Wing

In 1939, after warnings from leading physicists including Albert Einstein about Germany’s atomic bomb program, the United States began its own project to develop a nuclear bomb. On July 16, 1945, after years of research and nearly 2 billion dollars spent (nearly 26 billion in 2016 dollars), an atomic bomb was successfully detonated on the bombing and gunnery range of  Alamogordo Army Airfield in New Mexico.

While the atomic bomb was being developed, the 509th Composite Group, under the command of Colonel Paul W. Tibbets, conducted long range training missions at Wendover Field, Utah and Batista Army Airfield in Cuba. The group’s B-29 Superfortresses were modified to carry the unusually long and wide “Thin Man,” “Little Boy,” and “Fat Man” atomic bombs.

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The Enola Gay the B29 Superfortress that dropped the first atomic bomb on Hiroshima



In July 1945, the 509th Composite Group deployed to Tinian in the Mariana Islands to prepare for operations against Japan. For security reasons, their planes were given identification markings of other B-29 units to keep their presence a secret.

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Colonel Paul W. Tibbets waving out the cockpit of the Enola Gay

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The mushroom cloud from the “Fat Man” bomb over Nagasaki

On August 6, 1945, the B-29 Superfortress, Enola Gay, piloted by Colonel Tibbets dropped a uranium bomb named “Little Boy” on the city of Hiroshima. Three days later, the Superfortress, Bockscar piloted by Major Charles W. Sweeney dropped a plutonium bomb named “Fat Man” on Nagasaki. The two bombs immediately killed an estimated 120,000 people including 20,000 Japanese soldiers. Thousands more would later die from radiation sickness.

On August 15, 1945, Japan announced its surrender, with an official surrender ceremony taking place in Tokyo Bay on September 2, 1945.

After WWII, the 509th Composite Group took part in Operation Crossroads, the atomic bomb testing’s at Bikini Atoll in the Marshall Islands.  On July 1, 1946, a 509th B-29 Superfortress named “Dave’s Dream” dropped an atomic bomb over a group of target ships gathered in Bikini’s lagoon. Although the bomb missed its aiming point by 2130 feet, (649 meters) it did manage to sink 5 ships and seriously damage 14 others.

Upon returning to the US, the 509th Composite Group became one of the founding units of the US Air Force’s nuclear capable Strategic Air Command (SAC), but was de-activated in June 1952. In 1993 the unit was re-activated as the 509th Operations Group and today is the only US Air Force unit to operate the B-2 Stealth Bomber.

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Nuclear explosion over The Bikini Atoll on July 25, 1946. Taken during the nuclear bomb testing’s of Operation Crossroads

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M1938 Field jacket from a member of the 509th Composite Group



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Pilots from the 509th Composite Group in 1946

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Crew of “Dave’s Dream” from the 509th Composite Group during Operation Crossroads

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B-29 Superfortress with Nose art insignia of the 509th Composite Group

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One thought on “509th Composite Group-Bringers of the Atomic Age

  • Peter Kubicek says:

    Fascinating history of the development of the atomic bomb, which, after all, ended the Second World War.

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