An actuator control arrangement includes a hydraulic actuator having a housing and a piston rod axially moveable within the housing, a stop disposed within the housing to limit the extent of movement of the piston rod into the housing, and a solenoid valve arranged between a pressure source and the actuator. The solenoid valve is switchable between a first mode and a second mode in response to an electric control signal, wherein, in the first mode, the solenoid valve creates a fluid flow path from the pressure source to the actuator so as to locate the stop in its neutral position and in the second mode, the solenoid valve creates a fluid flow path to release pressure from the actuator to permit the stop to move to its retracted position. In the event of electrical failure, the stop will set the actuator to its neutral position.

A method and apparatus for positioning a control surface. A desired position for the control surface associated with an aerodynamic aircraft structure is identified. The control surface is moved to the desired position using an electronically controlled rotary actuator system located inside of the aerodynamic aircraft structure, wherein a shape of the aerodynamic aircraft structure with the electronically controlled rotary actuator system has a desired aerodynamic performance.

An electro hydrostatic actuator comprises a hydraulic pump driven by an electric motor to supply hydraulic fluid to a hydraulic actuator. The pump comprises an inlet and an outlet for the hydraulic fluid and an active flow path arranged therebetween such that, in an active mode of operation when the pump is driven by the electric motor, hydraulic fluid is actively drawn in through the inlet and exhausted out through the outlet. The pump further comprises a bypass flow path arranged to open between the inlet and outlet such that, in a damping mode of operation when the pump is not driven by the electric motor, hydraulic fluid is able to pass through the pump along the bypass flow path between the inlet and outlet.

A starboard wing of an aircraft includes various movable aerodynamic surfaces, such as a spoiler, slat, aileron, flap or the like. An actuator is provided for moving each such surface. The location and mounting of the actuator of the starboard wing is symmetrical about the centreline of the aircraft to that of the actuator of the port wing. The location of the piston, arm or other mechanical output of the actuator is at a centre portion of the actuator (i.e. at or near the midline of the actuator. The input port(s) for power is/are also at the centre portion. The actuator for the starboard wing may thus be substantially identical to the actuator for the port wing.

Distributed trailing edge wing flap systems are described. An example wing flap system for an aircraft includes a flap and first and second actuators. The flap is movable between a deployed position and a retracted position relative to a fixed trailing edge of a wing of the aircraft. The first and second actuators are configured to move the flap relative to the fixed trailing edge. The first actuator is operatively coupled to the second actuator via a shaft. The first actuator is actuatable via pressurized hydraulic fluid to be supplied from a hydraulic system of the aircraft to the first actuator via a hydraulic module operatively coupled to the first actuator. The first actuator is configured to control movement of the second actuator via the shaft when the hydraulic system and the hydraulic module are functional. The second actuator is actuatable via an electric motor of the second actuator. The electric motor is selectively connectable to an electrical system of the aircraft. The electric motor is connected to the electrical system in response to detection of a failure of the hydraulic system or of the hydraulic module. The second actuator is configured to control movement of the first actuator via the shaft when the electric motor is connected to the electrical system.

An actuation system for resolving the effects of force-fight between multiple stages within an actuator coupled to an aircraft flight control member includes a yoke configured for connection to the flight control member. A first control member is operatively coupled to a first actuator and configured to cause the first actuator to output a first force to the yoke, and a second control member is operatively coupled to a second actuator and a third actuator symmetrically arranged on opposite sides of the first actuator. The second control member is configured to operate independent of the first control member and to cause the second actuator and the third actuator to output a second force to the yoke and a third force to the yoke respectively, wherein the combined force is substantially the same as the first force to effect motion of the flight control member.

An electrohydrostatic actuator, comprising an actuator for driving a component, a pump configured to pump hydraulic fluid for operation of the actuator, and a control valve for controlling passage of the hydraulic fluid between the actuator and the pump, wherein the control valve is movable between first and second positions. In the first position the control valve is configured to convey hydraulic fluid from the pump through the control valve for operation of the actuator, and in the second position the control valve is configured to fluidly disconnect the pump and the actuator, and circulate hydraulic fluid arriving from the pump back to the pump via a first constriction within the control valve.

An electro hydrostatic actuator comprising a hydraulic pump driven by an electric motor to supply hydraulic fluid to a hydraulic actuator, the pump comprising an inlet and an outlet for the hydraulic fluid and an active flow path configured therebetween such that, in an active mode of operation when the pump is driven by the electric motor, hydraulic fluid is actively drawn in through the inlet and exhausted out through the outlet. The pump further comprises a bypass flow path configured to open between the inlet and outlet such that, in a damping mode of operation when the pump is not driven by the electric motor, hydraulic fluid is able to pass through the pump along the bypass flow path between the inlet and outlet. The hydraulic pump is a rotary piston pump comprising a pump barrel driven to rotate by a motor shaft.

A control system may be used to control actuators that actuate movement of flight control surfaces of an aircraft. Each actuator is couplable to a flight control surface and includes a motion control assembly having a hydraulic motor and a drive path from the hydraulic motor to the flight control surface. Each hydraulic motor includes an extend port and a retract port. The system includes a hydraulic control module fluidly connected to the extend port and the retract port of each hydraulic motor and a controller operable to output hydraulic power from the hydraulic control module to the motion control assembly to actuate movement of the flight control surfaces. The controller is configured to identify an actuator that positionally leads the other actuators and reduce hydraulic power to the motion control assembly assigned to such actuator.

Distributed trailing edge actuation systems and methods for aircraft are described herein. An example aircraft includes a wing, a flap coupled to the wing, the flap movable between a stowed position and a deployed position, and a distributed trailing edge (DTE) actuation system including a flap actuator coupled to the wing to move the flap. The flap actuator includes an integrated hydraulic powered actuator and electric powered actuator. The flap actuator is operable in a hydraulic powered mode in which the hydraulic powered actuator is activated to move the flap, an electric powered mode in which the electric powered actuator is activated to move the flap, and a hybrid mode in which the hydraulic powered actuator and the electric powered actuator are activated simultaneously to move the flap.