A controllable flow deflection system for guiding the flow of a fluid medium in a desired discharge direction includes a steered deflection device mounted in a body or support member. The deflecting device includes a rotatable element containing at least one outlet opening for discharging the fluid medium which flows to the element from a reservoir. A driving and braking device is connected to the rotatable element. The one or more outlet openings are arranged so that the discharged fluid medium does not cause any torque on the rotatable element, or a torque is developed from a combination of two torque vectors symmetrical with respect to the axis of rotation of the element. Such a system may be used in a thrust system for steering a flying body member, in a secondary injection system, or in a hot gas motor, such as a vane motor.