A control valve for a multi-stage hydraulic actuator includes a valve body defining a translation axis, a spool disposed within the valve body and movable along the translation axis, and a flange. The flange is fixed relative to the spool and has an aperture disposed externally of the valve body to removably fix the spool to a spool of a redundant control valve independently connected to the multi-stage hydraulic actuator for mitigating force fights between actuators coupled to the control valve.

An electromechanical actuator assembly comprises a first actuator and a second actuator. The first actuator and the second actuator are coupled together end-to-end and are independently operable. A method of actuating a moveable element using an actuator assembly, comprises: coupling a first actuator between a fixed structure and a second actuator so that the first actuator is operable to move the second actuator relative to the fixed structure; coupling the second actuator to the moveable element; and moving the moveable element by moving the second actuator using the first 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.

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.

A failsafe vale provides “Hole-In-The-Wall” failsafe functionality for thin-wing aircraft control surface actuation systems having a geared rotary actuator powered by a hydraulic rotary motor. The failsafe valve is associated with the hydraulic rotary motor and mechanically connected to the control surface, and enables the flight control surface to return to an aerodynamically neutral failsafe position if electrical control and/or hydraulic pressure is lost. When the failsafe valve receives a normal command pressure from the hydraulic system, the valve is inactive and the actuation system operates normally. However, if there is a loss of electrical command capacity to control hydraulic valves and/or a loss of hydraulic pressure, the failsafe valve is activated and connects one of the motor hydraulic control lines to the case return line for the motor if the control surface is away from its failsafe position. Consequently, the control surface will be hydraulically powered or aerodynamically ratcheted to its failsafe position in the failure event.

A failsafe vale provides “Hole-In-The-Wall” failsafe functionality for thin-wing aircraft control surface actuation systems having a geared rotary actuator powered by a hydraulic rotary motor. The failsafe valve is associated with the hydraulic rotary motor and mechanically connected to the control surface, and enables the flight control surface to return to an aerodynamically neutral failsafe position if electrical control and/or hydraulic pressure is lost. When the failsafe valve receives a normal command pressure from the hydraulic system, the valve is inactive and the actuation system operates normally. However, if there is a loss of electrical command capacity to control hydraulic valves and/or a loss of hydraulic pressure, the failsafe valve is activated and connects one of the motor hydraulic control lines to the case return line for the motor if the control surface is away from its failsafe position. Consequently, the control surface will be hydraulically powered or aerodynamically ratcheted to its failsafe position in the failure event.

Inerters with friction disk assemblies, and aircraft hydraulic systems and aircraft including the same. An inerter comprises an inerter housing containing an inerter fluid, a threaded shaft extending within the inerter housing and fixed relative to the first terminal, and an inerter rod extending at least partially within the inerter housing and fixed relative to the second terminal. The inerter further includes a friction disk assembly that, together with the inerter fluid, is configured to damp a motion of the second terminal relative to the first terminal. The friction disk assembly includes a fixed portion and a rotating portion, and is configured such that rotation of the rotating portion generates a frictional torque that opposes the rotation of the rotating portion. In some examples, the inerter is a component of a hydraulic actuator, an aircraft hydraulic system including the hydraulic actuator, and/or an aircraft including the aircraft hydraulic system.

Inerters with friction disk assemblies, and aircraft hydraulic systems and aircraft including the same. An inerter comprises an inerter housing containing an inerter fluid, a threaded shaft extending within the inerter housing and fixed relative to the first terminal, and an inerter rod extending at least partially within the inerter housing and fixed relative to the second terminal. The inerter further includes a friction disk assembly that, together with the inerter fluid, is configured to damp a motion of the second terminal relative to the first terminal. The friction disk assembly includes a fixed portion and a rotating portion, and is configured such that rotation of the rotating portion generates a frictional torque that opposes the rotation of the rotating portion. In some examples, the inerter is a component of a hydraulic actuator, an aircraft hydraulic system including the hydraulic actuator, and/or an aircraft including the aircraft hydraulic system.

An aircraft assembly, having: a reference component; a first component and a first actuator, the first actuator configured to move the first component relative to the reference component; a second component and a second actuator, the second actuator configured to move the second component relative to the reference component; a position sensor configured to measure a position of the first component, and to output a position value, the sensor being capable of outputting a plurality of non-zero position values; and a controller configured to control the movement of the second component by the second actuator based at least partially on the position value output by the position sensor.

An aircraft assembly, having: a reference component; a first component and a first actuator, the first actuator configured to move the first component relative to the reference component; a second component and a second actuator, the second actuator configured to move the second component relative to the reference component; a position sensor configured to measure a position of the first component, and to output a position value, the sensor being capable of outputting a plurality of non-zero position values; and a controller configured to control the movement of the second component by the second actuator based at least partially on the position value output by the position sensor.