The B-47A (49-1900) bomber was the first to be built at the Boeing Aircraft Company in Witchita, Kansas. NACA High-Speed Flight Research Station obtained that B-47A Stratojet (NACA 150) to study the characteristics of a large, flexible swept-wing aircraft in 1953.
The B-47A testing resulted in reports that gave engineers and design teams around the country access to reliable information on the dynamic behavior and response characteristics that could be expected of large, flexible sweptwing airplanes, such as the Boeing KC-135 and the B-707 transport.