A turbofan with a fan casing and a nacelle which comprises a fixed structure, a movable assembly with a movable cowl and a slide, which is translationally movable between an advanced position and a retreated position in which the movable cowl is moved away from the fan casing in order to define a window open between a duct and the outside of the nacelle, a plurality of blades, each being mounted rotatably on the slide, where each blade is movable between a retracted position in which the blade is outside of the duct and a deployed position in which the blade is across the duct, a set of actuators for moving the slide and an operating system configured to move each blade from the retracted position to the deployed position, and vice versa.