be seen as the successful application of the Rapier design principles in a Mach 2 supersonic design. Hughes Aircraft would continue the development of the advanced fire control system and the GAR-9 missile. Development of the F-108 radar and missiles was continued by the USAF and the system was eventually used in the Lockheed YF-12 program. The final configuration for the rear cockpit in the YF-12A looked similar to that of the F-108 since it incorporated the same displays and controls required for the Hughes AN/ASG-18 fire control system. Design The initial F-108 configuration featured a very large "cranked" delta wing. There were fixed ventral stabilizers on the wings, mounted at mid-span, and a tall all-moving vertical tailfin, supplemented by two ventral stabilizers that extended when the landing gear retracted. Although some earlier versions of the design had separate tailplanes or forward canards, both were abandoned in the final design. The large fuselage and wing had two and five fuel tanks, respectively, giving an estimated combat radius of some . Top speed was estimated at , about Mach 3, at . The aircraft was powered by two General Electric J93 turbojet engines, also used in North American's XB-70 Valkyrie bomber, in the fuselage. The F-108 was intended to carry the Hughes AN/ASG-18 radar, the U.S.'s first pulse-Doppler radar set. It was to have look-down/shoot-down capability, but could track only one target at a time. The radar was paired with an infra-red search and tracking (IRST) system on the wing leading edges. The radar was used to guide the Hughes GAR-9 (later redesignated AIM-47) air-to-air missile, three of which would be carried on a rotary launcher in an internal weapons bay. The GAR-9 was a very large, long-range weapon with its own radar set for terminal homing. It was intended to fly at Mach 6, with a range of almost . XQ-11 target drone As part of WS-202A, a design for a high-speed (Mach 3+) aerial target for use in testing the F-108's weapons system was proposed. The Wright Air Development Center requested the designation XQ-11 for the target design; the request was denied due to the early stage of development, and the F-108 program was cancelled before further work was undertaken. Specifications (XF-108) See also References Notes Citations Bibliography External links Anigrand Models produces 1/72 and 1/144 scale resin kits of the XF-108 F-108 Rapier page on GlobalSecurity.org Additional illustrations,