Abstract: System for controlling an aerodynamic surface (1) (flap, aileron, control surface, etc.) of an aircraft. According to the invention, this system comprises: an electric machine (8) which can operate either as a motor or as a generator, the output of which is connected mechanically to said aerodynamic surface (1); and a logic device (17) receiving information about the operating status of the electrical power supply (11) of the machine (8) and of the hydraulic servocontrol (2, 5) and controlling the actuation of said surface (1) either by said machine (8) or by said servocontrol (2, 5).

Abstract: A system for controlling the tab (6) of an aircraft control surface (3) having a pair of position sensors (12 and 15) that supply information regarding the turning of the control surface (3) and the position of a jack (13), respectively, on the basis of signals generated by the sensors (12 and 15) as well as possibly on the basis of at least one parameter (p) originating from the aircraft, such as airspeed, positions of lift-augmenting devices, forces exerted by the pilot on a control, etc., and which formulates a command for the jack (13).

Abstract: Flight control system for aircraft of the type provided with ailerons, elevators, upper surface spoilers, and upper surface air-brakes, a rudder and horizontal stabilizers with variable angle of incidence, said system comprising an electric control, in some cases without any mechanical emergency control for said upper surface spoilers and air-brakes.According to the invention:the ailerons and elevators are electrically controlled without any mechanical aid,the rudder is mechanically controlled, andthe horizontal stabilizers with variable angle of incidence are electrically controlled with mechanical aid.the electrical flight controls are optimized.

Abstract: This invention relates to a digital-analog interface for insertion between the control circuit of a moving element and a transmitter of digital control signals.This interface comprises an inductive detector of the actual position of the moving element. The inductive detector has a single primary winding directly connected to an a.c. source and two secondary windings. The detector secondary windings are connected in parallel to one input of a summing circuit, through a first resistance of fixed value and through a second resistance of adjustable value, respectively. Means responsive to the transmitter digital control signals are provided to adjust the value of the second resistance. The output of the summing circuit is connected to the control circuit of the moving element.

Abstract: In a servocontrol device for controlling a control surface of an aircraft, which device is associated with a mechanical control member such as control column, wheel, pedals, and which comprises two identical double-acting hydraulic rams, integral with each other and each controlled by means of a slide valve, the slide valves each being controlled by a servovalve, whilst each servovalve is controlled by an electrical chain associated therewith, emitting an electrical control signal taking into account the displacements of said control member, the chains are connected to each other by crossed connections and they comprise apparatus for delivering equal signals to said servovalves.The invention is directed to the control of the control surfaces of an aircraft.