| A Series 200 BAC 111 modified with two contra-rotating circulation controlled rotors (shown above). In an effort to attack storage problems of tilt-and-fold rotors, NGTE created a rigid rotor with a circular/elliptical cross-section. Lift is generated by air blowing tangentially around the upper surface of the blades from narrow spanwise slots. The result is fewer, shorter blades and no need for flapping or drag hinges. Once the airflow to the slots is cut off, no significant lift is generated. With this rotor design, lift is independent of rotor speed. R&D on this program began in 1959. |
