Abstract: An hydraulic actuator composed of a double-acting actuator, a mobile switching member disposed in a housing connected hydraulically to the actuator, two fluid inlet and outlet pipes and a control member adapted to command the mobile switching member to move between a neutral configuration and an active service configuration. A variable speed pump system is connected to the housing by an auxiliary circuit; the mobile switching member has an active second configuration in which the actuator communicates with the auxiliary circuits, whereby the actuator, the pump system and the auxiliary circuit constitute a hydrostatic transmission.

Abstract: The system in accordance with the invention provides braking while an aircraft (1) is being towed on the ground by a tractor vehicle (2) which is mechanically connected to the aircraft and which is fitted with a brake device under the control of a brake pedal (27), with the aircraft being fitted with a braking circuit. The system comprises a towing brake member (7) disposed in the aircraft's braking circuit line (34) for connecting the brake control member (27) of the vehicle to the towing brake member (7) of the aircraft.

Abstract: A hydraulic circuit for aircraft braking, the circuit including wheel brakes (11) fed with hydraulic fluid by servovalves (8, 22) mounted in a normal circuit and in an emergency circuit. The normal circuit and the emergency circuit are selectively connected to the wheel brakes by switching devices (9) and protected from excessive loss of hydraulic fluid by hydraulic fuses (6, 24). The servovalves of the normal circuit are associated in pairs. The hydraulic fuses (6) of the normal circuit are disposed upstream from the servovalves (8) on lengths of line (5) which are common to each pair of servovalves. The devices (9) for switching from the normal circuit to the emergency circuit are disposed downstream from the servovalves (8).