A turbofan with a nacelle having a slider that is movable between an advanced position and a retracted position to open a window between a duct and the outside, blades, each one being able to move in rotation between a stowed position and a deployed position, and a maneuvering system that moves each blade, a transmission arrangement that rotates the blades one after the other, a drive system that converts the translational movement of the slider into a rotational movement of a first blade and that has a ball screw system, an epicyclic gear train, and an assembly of arms and levers.