below the centerline of the aircraft. The RJ55 was installed inline with the fuselage in the extreme rear, as if it were the exhaust of a conventional engine installation. There was a significant empty space above the J67 for ducting. Wings and control surfaces All of the control surfaces were pure delta wings. The main wing was swept at 55 degrees, and could be rotated around the spar to provide variable incidence. For takeoff and landing, the wing was tilted upwards to increase the angle of incidence while keeping the fuselage nearly horizontal. The length of the fuselage made it difficult to achieve the same end by tilting the entire aircraft upwards, which would have required a very long extension on the landing gear. The system also allowed the fuselage to fly flat to the airflow at various speeds, setting the trim angle independent of the aircraft as a whole. This decreased trim drag, thus improving range. The wing was split at about two-thirds of the span. The portion outside of this line able to rotate independently of the rest of the wing. These movable portions acted as large ailerons, or as Republic called them, tiperons. To keep the surface area in front and behind the pivot point somewhat similar, the split line was closer to the fuselage in front of the pivot. Large conventional flaps ran from the fuselage to the tiperons. Hard points for drop tanks were available at about of the way out from the wing root. The horizontal stabilizers were seemingly undersized, and mounted below the line of the wing. The larger vertical fin was supplemented by a ventral fin for high-speed stability. This fin folded to the right, as seen from behind, during takeoff and landing to avoid hitting the ground. Two petal-style air brakes were mounted directly behind the horizontal surfaces, opening out and up at about a 45° angle into the gap between the horizontal and vertical surfaces. A provision for a braking parachute is not evident on the mock-up or the various artwork, although this was common for aircraft of the era. Fuselage The fuselage was completely smooth, with a high fineness ratio for low drag at supersonic speeds. The design was developed prior to the discovery of the area rule, and does not display any of the wasp waisting common to aircraft primarily developed after 1952. The fuselage contours were mainly