The project was originally designated XA-44 in 1945 under the old "attack" category. An unusual forward-swept wing-design powered by three J35-GE turbojets, the project was developed in parallel with Convair's XB-46. The original design had a wing with a 12° forward-sweep and a solid nose section, but when the Army Air Force revamped the advanced attack aircraft requirement into a light bomber requirement in 1946, the aircraft was redesignated XB-53 and the wing redesigned with a 30° forward-sweep and 8° dihedral that was borrowed from German wartime research, but also a glazed nose section. The swept-forward configuration would give the aircraft a greater climb rate and maneuverability.[1] [2] It looked promising enough at one point for the Army Air Force to consider canceling the XB-46 in favor of the XA-44, since there was not enough funding for both.[3]
Classified as a medium bomber, the XB-53 would have carried up to 12,000 pounds of bombs as well as 40 High Velocity Aerial Rockets (HVAR) mounted on underwing pylons.[3]
Convair argued for completion of the XB-46 prototype as a flying testbed, without armament and other equipment, and with the substitution of two XA-44s for the other two B-46 airframes on contract. The Air Force ratified this in June 1946 but the project did not progress, nor were additional B-46s built. The XB-53 program was reinstated in February 1949 but only for a short while.