Boeing XB-56

The Boeing XB-56 was a proposal to rebuild the B-47 Stratojet jet bomber with new engines. The B-47 used six General Electric J47 turbojets in four nacelles, and the idea was to fit one more powerful engine to each nacelle so the bomber would be lighter, simpler and stronger. A contract of January 1950 covered one B-47B, and the Allison J35, the J71 and the Pratt and Whitney J57 were each considered in turn, but engine delays and the priority given to the B-52 held the work back. The original designation was YB-47C, and a production version was planned as the RB-56A. The program was cancelled in December 1952 before the prototype was converted, and the aircraft became a ground instruction airframe.