A turbofan having a nacelle comprising a slider mobile in translation between advanced position and retracted positions to open a window between a duct and the exterior, a plurality of blades, each one being rotatably mobile on the slider between stowed and deployed positions, and a maneuvering system moving each blade and comprising for each blade, a shaft rotatably mobile on the slider and onto which the blade is fixed, for each shaft, a balance beam fixed to the shaft and having first and second ends, for three consecutive balance beams, two connecting rods where the first connecting rod is mounted articulated between the first balance beam and the second balance beam, and where the second connecting rod is mounted articulated between the second balance beam and the third balance beam, and an actuation system rotating one of the connecting rods in one direction and in the other.