1946, NASA history collection. NASA public domain image colelction.

The Boeing B-29 Superfortress is a four-engine heavy bomber designed by Boeing during the Second World War. It was used primarily by the United States Army Air Forces in the Pacific theatre of World War II and also during the Korean War. The B-29 was one of the largest aircraft of its time, with a wingspan of 141 feet and a length of 99 feet. It had a top speed of 357 mph and a range of over 3,000 miles. The B-29 was also the first bomber to have a pressurised cabin, allowing it to fly at high altitudes without the need for oxygen masks. One of the most famous B-29s was the Enola Gay, which dropped the atomic bomb on Hiroshima, Japan on 6 August 1945.