Abstract: A connection for a lower attachment for a trimmable horizontal stabilizer actuator (THSA) for connecting the lower attachment to a flight control surface. The attachment includes: a surface bracket for coupling to the flight control surface, the surface bracket mounted about a gimbal of the lower attachment by a bushing disposed between the gimbal and the surface bracket; a failsafe plate fittingly engaged on a first end of the bushing; and a tightening ring mounted on a second end of the bushing opposite the first end and secured to the surface bracket by at least one contact screw, such that the contact screw is operable to urge the bushing against the failsafe plate.

Abstract: The present invention goes away from conventional teaching and provides a stator having a construction that creates or allows induced currents thus providing a damping function. This effect is provided by forming the stator back iron of a solid piece of iron material or iron alloy as opposed to a stack of laminations or compressed powder.

Abstract: A damping assembly is described herein for use in a device having moving aerodynamic surfaces including a first component comprising a back iron and at least one permanent magnet, said at least one permanent magnet providing a first magnetic field, and an electrically conductive second component, said electrically conductive second component and said first component being positioned coaxially about a central axis with said at least one permanent magnet being positioned between said back iron of said first component and said electrically conductive second component; the assembly further comprising means for rotating one or both of said at least one permanent magnet of said first component and said electrically conductive second component about said central axis to cause relative rotational movement between the at least one permanent magnet and second component, to thereby induce a variable magnetic flux in said electrically conductive second component and cause eddy currents to develop.

Abstract: An electro hydrostatic actuator (EHA) comprises a hydraulic pump and an electric motor driving the hydraulic pump. The hydraulic pump comprises an inlet and an outlet for hydraulic fluid and an active fluid 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 hydraulic pump further comprises a bypass flow path arranged between the pump inlet and outlet, such that, in a damping mode of operation, hydraulic fluid is able to freely flow between the inlet and outlet in either direction.

Abstract: A servo valve torque motor apparatus including a pair of pole pieces; one or more permanent magnet(s) held between the pole pieces an armature supported between the pole pieces for rotation about an axis; the armature being for connection to a member that resists rotation of the armature; and a coil on the armature; wherein when an electrical current is passed through the coil the armature is rotated against the member; and wherein the magnet(s) is/are secured to the two pole pieces by mechanical fixings passing through holes in the magnet(s).

Abstract: A compound planetary gear train includes a sun gear, a stationary annulus gear, a first set of planet gears meshing with the stationary annulus gear, a moving annulus gear and a second set of planet gears meshing with the sun gear and the moving annulus gear. The planet gears are biased into contact with the annulus gears.

Abstract: A Stability and Command Augmentation System (SCAS) for an aircraft, the SCAS including, a first input shaft providing a first rotational input; a second input shaft providing a second rotational input; and a device for summing the first and second rotational inputs to give a rotational output for controlling an actuator. A method of operating a SCAS on an aircraft, the method including providing a pilot input order in the form of a rotating first shaft, providing an augmentation input order in the form of a rotating second shaft, summing the rotation of the pilot input order and the augmentation input order to give an output order; and using the output order to control an actuator.

Abstract: A rotary actuator for controlling a flight control surface and a flight control surface actuation assembly including the rotary actuator. The actuator comprises a rotary output shaft for driving a flight control surface, a locking mechanism for selectively preventing rotation of the rotary output shaft and a torque limiter for allowing the locking mechanism to be bypassed upon the locking mechanism experiencing a torque above a predetermined limit.

Abstract: There is disclosed a method of monitoring the health of an abradable seal located on a piston of an actuator, the method comprising the steps of: (i) measuring an initial velocity of said actuator piston while said actuator is maintained in a passive condition at an initial time; (ii) operating said actuator; (iii) measuring a subsequent velocity of said actuator piston while said actuator is maintained in a passive condition at a subsequent time; (iv) repeating steps (ii)-(iii) and either: recording or outputting the measured subsequent velocities over time; or determining a health status of said actuator when said subsequent velocity has increased above a predetermined amount.

Abstract: An assembly comprises a component and a spherical bearing mounted in a bore of the component. The spherical bearing comprises an outer race received within the component bore, an inner spherical member mounted for rotation within the outer race and a releasable retaining element for releasably retaining the outer race in the component bore. The outer race and the component comprise interengaging indexing formations whereby said outer race may be mounted within said component bore in a plurality of angular positions relative to the longitudinal axis (A) of the component bore.

Abstract: An electrical motor including a stator, said stator comprising a back iron, a plurality of teeth extending therefrom, and windings wound around said teeth; a rotary body comprising permanent magnets positioned between said stator and said rotary body; said rotary body being coaxially rotatable relative to the stator about a central axis; means for rotating said rotary body about said central axis of rotation relative to said stator, and wherein said back iron of said stator further comprises a first loop of electrical resistive wire extending therein.

Abstract: An actuator including a pair of load sensors arranged in the load path through the actuator. The load sensors are antagonistically preloaded and their outputs electrically connected to a processor for calculating a load in the actuator from the difference in loads measured by the respective load sensors.

Abstract: A screw (20) assembly for an actuator (10) is described comprising: a screw (20); a nut (22) threaded on said screw (20), such that rotation of said screw (20) causes axial movement of said nut (22); a stop located at an end of said screw (20) and defining an axial limit of said nut (22); a first feature located on said nut (22); and a second feature located on said stop; wherein said first and second features are configured to cooperate with one another substantially upon contact of said nut (22) with said stop so as to indicate an amount of free movement between said nut (22) and said screw (20).

Abstract: A flight control actuator drive including a first motor for providing a first rotational input, a second motor for providing a second rotational input and a speed summing device for combining the first and second rotational inputs into a rotational output for controlling an actuator. The speed summing device comprises first and second input gears to which the first and second motors are connected via first and second irreversible gears so that the first and second input gears can each transmit power in one direction only. The speed summing device may be a planetary gear assembly.

Abstract: A gearbox includes two axially spaced epicyclic gear trains, each having a sun gear, axially spaced planet gears carried by a planet carrier, and a ring gear fixed to the gear box. One of the planet gears engages with the fixed ring gear, and another of the planet gears engages with an output ring gear. The sun gears of the two gear trains are mounted on a single shaft. The planet carriers of the two gear trains are mounted on a shaft so that they can freely rotate but have limited axial motion along the shaft. The two output ring gears are helical gears of opposite handedness.

Abstract: A control valve comprises a first spool 22, a second spool 24 encircling at least part of the first spool 22 and angularly moveable relative thereto, and a sleeve 32 encircling at least part of the second spool 24, the second spool 24 being angularly moveable relative to the sleeve 32, the first and second spools 22, 24 having first and second series of ports 28, 30 registrable with one another, depending upon the relative angular positions of the first and second spools 22, 24, to control communication between at least a pressure line 16, a return line 18 and a control line 50 provided in or connected to the sleeve 32, the second spool 24 and the sleeve 32 having third and fourth series of ports 66, 68, axially spaced from the first and second series of ports 28, 30 and registrable with one another, depending upon the relative angular positions of the second spool 24 and the sleeve 32, to control communication between at least the control line 50 and the return line 18, and latch means 56 operable to resist

Abstract: A device (13) for detecting the breakage of a primary path in a flight control actuator, said actuator having a primary path (1) comprising a rotary hollow screw (2), a secondary path (10) comprising a safety rod (3) that reacts the load passing through the screw (2), said device (13) being characterized in that it comprises a position sensor (15), connected to the screw (2), to measure information representative of the angular position thereof, and a disconnection system (17) able to disconnect the screw (2) position sensor (15) in the event of relative movement of the rod (3) with respect to the screw (2) if there is a break in the primary path (1).

Abstract: The invention relates to a flight-control actuator comprising a control screw (1) that engages with a primary nut (2), the actuator also comprising a secondary nut (5) that engages with the control screw in the event the primary nut fails. The primary nut and the secondary nut are remote from one another, the secondary nut moving substantially along a portion of the screw that is usually not fitted with the primary nut.

Abstract: The disclosure relates to a device for testing means of detecting the loading of the secondary path of a flight control actuator of the type including a primary path and a secondary path able to take up the effort of the primary path in the event of a breakdown of the latter, wherein a tool is able to press against at least one zone of at least one element of the secondary path, as well as a lever arm which by tilting allows the tool to press against the zone so that it exerts a traction and/or compression force on the secondary path, the lever arm being mounted pivotingly on a support able to be fastened on a structure that is mechanically independent of the secondary path.

Abstract: A control valve comprises a first spool 22, a second spool 24 encircling at least part of the first spool 22 and angularly moveable relative thereto, and a sleeve 32 encircling at least part of the second spool 24, the second spool 24 being angularly moveable relative to the sleeve 32, the first and second spools 22, 24 having first and second series of ports 28, 30 registrable with one another, depending upon the relative angular positions of the first and second spools 22, 24, to control communication between at least a pressure line 16, a return line 18 and a control line 50 provided in or connected to the sleeve 32, the second spool 24 and the sleeve 32 having third and fourth series of ports 66, 68, axially spaced from the first and second series of ports 28, 30 and registrable with one another, depending upon the relative angular positions of the second spool 24 and the sleeve 32, to control communication between at least the control line 50 and the return line 18, and latch means 56 operable to resist