At the end of World War II, the Glenn L. Martin Company began the XA-45 attack aircraft project. It quickly became clear that its design ? two turbojet and two turboprop engines - is not the best solution. So the XA-45 was transformed into the XB-51 jet bomber project. October 28, 1949 - the first flight of the Martin XB-51 bomber.
The XB-51 was a medium-sized plane with a T-shaped tail and an unusual arrangement of engines. 2 ? General Electric J47-GE-13 with a thrust of 23 kN was placed in the ventral pylons closer to the nose, and one in the tail. The maximum speed is 1036 km/ h, the flight range is 1730 km. Armament ? 8 ? 20 mm guns M24 + 8 ? missiles or up to 4720 kg bombs.
2 XB-51 prototypes were built. Tests have shown that the aircraft is inferior to the English bomber English Electric Canberra. As a result, Glenn L. Martin Company acquired a license for its production under the designation B-57 Canberra, and the XB-51 project was closed.