Abstract: An upper attachment system for a trimmable horizontal stabiliser actuator (THSA) comprises: a housing, holding a yoke and a ballscrew; a nut coupled to the housing and cooperating with the ballscrew such that rotation of the ballscrew relative to the nut results in linear motion of the ballscrew; a recess formed between the yoke and the ballscrew and arranged to receive, in use, an upper part of a tie bar of the secondary load path of the actuator; and a biasing mechanism arranged such that, in use, when no axial load is applied to the tie bar, the yoke and the ballscrew are held by balanced forces from the biasing mechanism in a position within the recess.

Abstract: A spoiler actuator can be operated by applying high pressure to a first chamber of the actuator on receipt of a command to extend the spoiler; applying high pressure to a second chamber of the actuator on receipt of a command to retract the spoiler; and on failure of a supply of the high pressure actuating an anti-extension valve to prevent extension of the spoiler; disengaging the anti-extension valve to permit extension if pressure applied to the anti-extension valve exceeds a predetermined force of a spring biasing the anti-extension valve to the engaged position, wherein additional force is applied to the anti-extension valve if the spoiler is retracted beyond a neutral position.

Abstract: An apparatus for pumping a fluid from a fluid inlet to a fluid outlet is disclosed. The apparatus comprises: a spool axially movable within a cavity, wherein a first chamber is located at a first axial end of the cavity and a second chamber is located at a second axial end of the cavity, wherein the volume of the first chamber and the second chamber varies depending upon the axial position of the spool within the cavity; a valve movable between a first position and a second position, wherein in the first position the valve is configured to convey fluid from the fluid inlet to the first chamber and from the second chamber to the fluid outlet, and in the second position the valve is configured to convey fluid from the fluid inlet to the second chamber and from the first chamber to the fluid outlet.

Abstract: An actuator is provided with means for controlling whether or not forces are transferred between a cylinder 12 (controlled by a motor of the actuator) and an output shaft 14. The output shaft 14 is located between the cylinder 12 and the control rod 18, 38. The cylinder 12 coaxially surrounds the output shaft 14, and the output shaft 14 in turn coaxially surrounds the control rod 18, 38. The control rod 18, 38 has one or more splines 20 on its outer surface facing the output shaft 12. The output shaft 14 has one or more holes 15, each containing a ball bearing 16.

Abstract: A lower attachment system for a trimmable horizontal stabiliser actuator comprising: a ballnut for being disposed on a screwshaft of the actuator and forming a part of a primary load path of the lower attachment system; a trunnion connected to the ballnut and forming a part of the primary load path of the lower attachment system; a failsafe plate disposed about the trunnion and forming a part of a secondary load path; a secondary connection connected to the failsafe plate and forming a part of the secondary load path; a sheet plate attached to a first mounting point on the secondary connection and a second mounting point on the ballnut; and an adjustment mechanism provided with the sheet plate for adjusting the size or position of the sheet plate to adapt it to fit a distance between the first and second mounting points.

Abstract: A test apparatus is provided for testing a sensorless check device of an actuator. The sensorless check device is arranged to be used by mechanically moving a check device pin from a resting position to an actuation position and then releasing the check device pin to allow it to return to a resting position urged by an elastic return mechanism. The test apparatus comprises: a piston for contact with an actuator surface associated with the check device pin; a piston spring for urging the piston toward the actuator surface, wherein the piston spring is softer than the elastic return mechanism of the check device; and an adjustment and testing mechanism.

Abstract: There is provided a method of manufacturing a housing configured to hold an actuator and an electronic control unit for the actuator. The method comprises additively manufacturing the housing as a single piece, wherein the housing comprises a central portion configured to house the actuator, and one or more side portions configured to house components of the electronic control unit.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Disclosed is an actuator for varying the position of a flight control surface on an aircraft, wherein the actuator comprises a no-back device including a backlash adjuster, which is arranged to select a plurality of different backlash lengths. The backlash adjuster may be a nut which moves relative a housing of the no-back device by rotating the nut. Also disclosed is a method of adjusting the backlash (B) in a flight control surface actuator, by moving the backlash adjuster axially to adjust the backlash (B) to a desired value.

Abstract: An abradable seal is provided, comprising an outer ring arrangement and an energiser for urging said outer ring arrangement against an opposing surface, wherein an outermost surface of said outer ring arrangement defines a sealing surface of said abradable seal; wherein said outer ring arrangement is configured such that after a first period of operation said sealing surface suddenly transitions from having a relatively large surface area to having a relatively small surface area, so as to cause a sudden increase in internal leakage across the seal at said transition.

Abstract: An actuator control arrangement is provided comprising a pair of rotary control valves used in combination to control the operation of an actuator. The rotary control valves are driven synchronously through a hydraulic or mechanical coupling. Each rotary control valve has a by-pass mode which activates in the event of a jam. In addition each rotary control valve has a mechanism for activating the by-pass mode absent any jam. The actuator control arrangement further comprises a circuit coupling a pilot control and/or a flight control computer (FCC) to one or both of the mechanisms for remotely switching the rotary control valve(s) from an active mode to a by-pass mode under control of a pilot or FCC.

Abstract: A planetary gear assembly is provided, comprising a first planetary gear stage and a second planetary gear stage. The first planetary gear stage comprises a first sun gear, first planet gears and an outer ring gear, and the second planetary gear stage comprises a second sun gear, second planet gears and one or more output ring gears. The outer ring gear and the second sun gear are the same component, and the first planetary gear stage is located within the second planetary gear stage.

Abstract: A connecting rod assembly for a flight control surface actuation system, the assembly comprising a connecting rod for connecting a flight control surface to a rotary actuator and a position sensor mounted to the connecting rod for sensing the position of the connecting rod relative to a rotary actuator.

Abstract: An actuator drive disconnection system comprises a housing and a drive coupling mounted in the housing, the drive coupling coupling a drive motor to an actuator drive train. A manually operable drive disconnection mechanism selectively moves the drive coupling from a first position in which the motor and actuator drive train are coupled and a second position in which the motor and actuator drive train are disconnected. The drive disconnection mechanism comprises an operating element which is manually extended from the housing to move the drive coupling from the first position to the second position.

Abstract: An electrical connection comprises a first connector, a second connector, a first wall surrounding the first connector, and a second wall surrounding the second connector. The first wall is configured to fit inside the second wall when the first and second connectors are connected. The first and second walls include leading faces comprising first and second chamfered portions, respectively. The first and second chamfered portions are angled complementarily for guiding the first wall inside the second wall during connection of the first and second connectors.

Abstract: A lower attachment system for a trimmable horizontal stabilizer actuator (THSA) includes a screwshaft forming a part of or coupled to a main screw of the actuator, the screwshaft having an axial direction and a primary ballnut disposed on the screwshaft and forming a part of a primary load path of the lower attachment system. The THSA also includes a lower secondary nut and an upper secondary nut as well as a secondary connection arranged for axial and rotational movement and coupled to each of the lower secondary nut and the upper secondary nut. The secondary connection is arranged to be loaded when the secondary load path is loaded and the secondary load path also includes the upper and lower secondary nuts.

Abstract: A hydraulic circuit comprising an actuator having an extension chamber and a retraction chamber, a bypass passage provided in the hydraulic circuit between defined between the extension chamber and the retraction chamber, and a damping device. The damping device includes first and second chambers separated by a wall, a first movable element received within the first chamber and a second movable element received within the second chamber. The first moveable element is movable from its closed position against the force of the first spring by entry of fluid into the second chamber, and the second movable member being movable from its closed position against the force of the second spring by entry of fluid into the first chamber.

Abstract: An upper attachment system for a trimmable horizontal stabilizer actuator (THSA) comprises: a housing, holding a yoke and a ballscrew; a nut coupled to the housing and cooperating with the ballscrew such that rotation of the ballscrew relative to the nut results in linear motion of the ballscrew; a recess formed between the yoke and the ballscrew and arranged to receive, in use, an upper part of a tie bar of the secondary load path of the actuator; and a biasing mechanism arranged such that, in use, when no axial load is applied to the tie bar, the yoke and the ballscrew are held by balanced forces from the biasing mechanism in a position within the recess.