An assembly for a nacelle, which includes a fixed cowl, a movable cowl that is movable between a closed position and an open position, and including an upper edge and a lower edge and, between the two edges, a reinforcing rib. The fixed cowl includes, an upper reinforcing rib and a lower reinforcing rib, a hinge including a fixed part attached to the upper reinforcing rib of the fixed cowl, a movable part attached to the reinforcing rib of the movable cowl, and at least two locks, each one including a first part secured to the lower reinforcing rib and a second part secured to the reinforcing rib of the movable cowl. An assembly of this kind serves to provide access to the inside of the nacelle while ensuring that the cowls remain sufficiently rigid.