A hinge assembly (4) for rotatably mounting a control surface (3) on an aircraft comprising an actuating shaft (9), a support element (16) configured to mount the actuating shaft to a first component of an aircraft and a hinge element (17) configured to mount the actuating shaft (9) to a second component of an aircraft, wherein the actuating shaft (9) is slidabty mounted to the support element (16) and configured to slide along its longitudinal axis relative to the support element (16), and the hinge element (17) engages with the actuating shaft (9) so that the actuating shaft and the hinge element are urged to rotate relative to each other about the longitudinal axis of the actuating shaft when the actuating shaft is urged to slide along its longitudinal axis, such that one of said first and second components is urged to rotate relative to the other said component about the longitudinal axis.