Northrop XB-35 (S/N 42-13603), the first XB-35 with dual contra-rotating 3-blade propellers. (U.S. Air Force photo) The XB-35 was the first Northrop flying wing bomber design. The initial contract for a single aircraft was awarded in November 1941 and amended to include another in January 1942. An order for 13 YB-35 service test aircraft was placed in September 1942 and another order for 200 production B-35Bs was placed in June 1943. It soon became apparent, however, that the aircraft would not be ready in time for use in World War II. Furthermore, jet bomber prototypes already on the drawing board made the propeller driven XB-35 obsolete before its first flight. The Army decided to continue the B-35 program, but only in test status. The B-35B order was canceled and the YB-35 order was amended to include conversions to jet powered aircraft (YB-49 and YRB-49A). The development of the XB-35 continued but at a slower pace, and the first flight of the XB-35 (S/N 42-13603) wasn't made until June 25, 1946.