Interstate XBDR

Lore & Background

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, essentially a flying wing with a small vertical stabiliser. It was intended to be powered by two Westinghouse 19B axial-flow turbojet engines buried in the wing near the wing roots. The planned warload was not detailed, but the assault drone was to be guided to its target via a television link.

Two prototypes (BuNos 37635 and 37636) were ordered, and tests of a 1/17-scale model were conducted in a NACA gust tunnel at Langley Field in 1944. These tests, requested by the Bureau of Aeronautics to determine load factors of the unusual configuration, initially encountered difficulty with the model's center of gravity. Once 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, and the order for the two prototypes was cancelled. No full-scale examples of the aircraft were built.

Reader's Guide

The Interstate XBDR represents an early attempt at a television-guided assault drone, reflecting the Navy's interest in remotely guided weapons during the latter stages of the Second World War. Its tailless flying-wing design was unusual for the period, and the use of twin turbojet engines buried in the wing roots was a forward-looking configuration. The wind tunnel tests, though initially problematic with center-of-gravity issues, were successfully completed and provided a recommended gust factor for the design. However, the project was cancelled before any full-scale aircraft were built, leaving the XBDR as a design study rather than an operational weapon. Its cancellation highlights the experimental nature of early drone and missile development, where many concepts were explored but few reached production. The XBDR remains the only aircraft ever assigned the 'BD' designation, marking it as a unique entry in the history of unmanned aerial vehicles.

Did You Know?

• It was designed as an 'assault drone' guided by a television link.
• Two prototypes were ordered but cancelled before any full-scale examples were built.
• Wind tunnel tests of a 1/17-scale model were conducted at Langley Field in 1944.