A deployment system for deploying a moveable wing surface (22) from a main wing section (8). The deployment system includes a plurality of swing arm assemblies (24,26) connecting the moveable wing surface (22) to the main wing section (8) and a drive means for deploying and retracting the moveable wing surface (22), wherein at least one of the swing arm assemblies (24,26) includes a swing arm (28) pivotably connected to the main wing (8) and a connector mechanism (34) for connecting the movable wing surface (22) to the swing arm (28). The connector mechanism (34) includes a first joint (36) having at least first and second rotational degrees of freedom and a second joint (40) having at least first and second rotational degrees of freedom and at least first and second translational degrees of freedom, said connector mechanism (34) being arranged to provide, in use, rotation of the moveable wing surface (22) about its longitudinal axis during deployment of the moveable wing surface (22), and allowing relative movement between the moveable wing surface (22) and the main wing section (8) due to thermal expansion and contraction of the movable wing surface (22).