An aeronautical thrust reverser including a sliding cowl, shutter flaps and deflection cascades. The reverser includes, for each flap, a return member hinged to the sliding cowl, to a driving connecting rod itself hinged to a front frame of the reverser, and to a return connecting rod itself hinged to the flap, the latter being moreover hinged by its rear end to the sliding cowl. The return member, the driving connecting rod and the return connecting rod form an actuation system capable of opening the secondary flow duct in a direct thrust configuration.