The YB-49 had a wingspan of 172 feet and a crew of six. It was powered by eight Allison J35-A-15 turbojet engines-upgraded to J35-A-19s in the YRB-49A variant-each producing 4,000 pounds of thrust.

The new interceptor was built with a narrow fuselage, embedded Allison J35 turbojet engines, and a thin, straight wing. Originally, the aircraft was built with swept wings, but the jet’s ...