U.S. Patent Specifications

In an aircraft, a pair of laterally spaced control surfaces adapted to be operated simultaneously to initiate a flight control movement of the aircraft about one of its manoeuvre axes, a control element mounted within the aircraft for rotation about a pivot axis, means operatively connected to the control element adapted to move it in rotation about its pivot in either direction from a neutral reference point, respective operative connexions carried by the control element adapted to provide simultaneous movement of each control surface in the same direction, the said connexions being disposed on the control element to follow a curvilinear path upon actuation thereof and operating linkages joining the said connexions to the respective control surfaces, the said connexions being further characterized by having an established spatial relationship with respect to each other and the pivot axis whereby the two connexions and the pivot form the apices of a triangle such that as said control element is moved in one direction or the other from neutral both control surfaces will be moved in the same direction but the linear components of the rotational movement of the control element transmitted through the said linkages will be of unequal magnitude causing one of said control surfaces to assume an effective control position differing from that of the other, the angles of deflexion of the respective control surfaces being inversely proportional to their relative distances from the manoeuvre axis.