X-1E Loaded in B-29 Mothership on Ramp

The X-planes are a series of experimental United States aircraft and rockets, used to test and evaluate new technologies and aerodynamic concepts. They have an X designator, which indicates the research mission within the US system of aircraft designations. The first, the Bell X-1, became well known in 1947 after it became the first aircraft to break the sound barrier in level flight. Most of the X-planes have been operated by the National Advisory Committee for Aeronautics (NACA) or, later, the National Aeronautics and Space Administration (NASA), often in conjunction with the United States Air Force. The majority of X-plane testing has occurred at Edwards Air Force Base. Some of the X-planes have been well publicized, while others have been developed in secrecy. Most X-planes are not expected to go into full-scale production.

NASA Photo Collection

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.