X-WING STABILITY AND CONTROL DEVELOPMENT AND WIND TUNNEL DEMONSTRATION TESTS - HELICOPTER, CONVERSION AND FIXED WING FLIGHT

The X-Wing aircraft combines the characteristics and attributes of a helicopter with those of a high aspect ratio transonic aircraft. A single wing/rotor lift and control system is combined with a conventional aircraft fuselage and tail. The proposed stability and control concept uses cyclic and collective modulation of rotor/wing circulation control air with hub moment feedback and conventional augmentation. The concept utilizes rotor/wing circulation control technology developed by DTNSRDC. Under a DARPA/DTNSRDC contract, a 25 foot diameter rotor/wing and breadboard control system model for a potential X-Wing demonstrator aircraft was fabricated and tested in the NASA/Ames 40 × 80 foot wind tunnel by the Lockheed California Company. The tests were completed in May, 1979. A brief description of the X-Wing aircraft, aerodynamic lift, and control concept which makes possible continuous lift and control during rotary, conversion between rotary and fixed, and fixed wing modes of flight is provided. Analytic methods used to predict control and stability characteristics are briefly described. Test results are compared with predictions and conclusions are drawn relative to a control configuration for a flight aircraft.