Referred to at the time as a "assault drone", and the only aircraft ever designated in the 'BD' series, the XBDR-1 was designed by Interstate in response to a Navy requirement in late 1943 and early 1944. The aircraft featured a tailless design, and was essentially a flying wing with a small vertical stabiliser. The XBDR-1 was intended to be powered by two Westinghouse 19B axial-flow turbojet engines, which were to be buried in the wing near the wing roots. The planned warload was not detailed, however it was planned that the assault drone would be guided to its target via a television link.
1/17-scale wind tunnel model of the XBDR-1 with alternative intakes
Two prototypes (BuNos 337635 and 37636) were ordered, and tests of a 1/17-scale model of the XBDR were conducted in a NACAgust tunnel at Langley Field in 1944. Requested by the Bureau of Aeronautics in an attempt to determine the load factors of the unusually configured aircraft, these tests initially encountered difficulty with the center of gravity of the model, but once this was resolved the tests were successfully carried out, and a gust factor of 1.22 was recommended for use in the design. Despite the successful testing the Navy decided not to pursue full-scale development of the aircraft, and the order for the two prototypes was cancelled.