Apparatus and methods provide for a controllable upper surface blown (USB) nozzle aperture. Aspects of the disclosure provide a powered-lift aircraft that utilizes a controllable nozzle aperture to maximize the spreading of the engine exhaust flow over the wing and USB flap surfaces to increase lift when desirable and to minimize exhaust plume contact with the wing and USB flap surfaces when minimizing drag is desirable. The controllable USB nozzle aperture includes movable upper, lower, and side duct surfaces to dynamically vary the geometry of the nozzle exit aperture to minimize the height and maximize the width of the exit aperture for maximum spreading of the exhaust plume or to maximize the height and minimize the width of the exit aperture for minimizing the spreading of the exhaust plume and minimizing the associated drag.