An aircraft assembly has: a cover with an outer aerodynamic surface and an aperture with a stop adjacent an edge of the aperture, and a moveable device for extending through the aperture in the cover. The moveable device carries a panel attached to the moveable device by a plurality of leaf springs. The assembly is configured so that when the moveable device is moved towards a retracted position the panel bears against the stop forming a substantially flush surface with the outer aerodynamic surface of the cover surrounding the aperture. The panel is displaced from the moveable device by elastic deformation of at least some of the leaf springs.