Patent ID: 6021976
Filing Date: 2000-02-08
Classification: B64C

Abstract:
In a helicopter including a main rotor, a tail boom having opposed sides and a rear end portion, a longitudinal circulation control slot along a predetermined one side of the tail boom and a thruster which is accommodated in the rear portion of the tail boom, a method of operating the thruster to control yaw of the helicopter, the method comprising the steps of:directing an air flow longitudinally along the tail boom toward deflecting vanes of the thruster, the deflecting vanes being arranged to deflect longitudinal air flow laterally toward opposed sides of the helicopter and toward openings in the sides of the rear portion of the tail boom; andadjusting, with respect to each opening, a height dimension of the opening using shutters, the height dimension being generally normal to both a longitudinal direction which corresponds to a general direction of extension of the tail boom and a lateral direction which is lateral to the longitudinal direction, the height dimension being generally symmetrical from opposed extremities of the opening such that a geometrical centre of the opening remains substantially static regardless of a status of the adjustment of the respective opening,wherein the shutters rotate about a longitudinal axis of the helicopter.