A linear electromechanical actuator with a main screw-nut assembly driven by a main motion device and having a hollow screw with an abutting surface; an anti-jamming piston arranged coaxially within the screw and shiftable between an engaged position in which locking dogs interfere with the abutting surface and a disengaged position in which the piston is free to slide within the screw; and actuating elements configured to shift the piston from the engaged to the disengaged position upon electrical or mechanical failure of the actuator. The actuating elements include a key axially movable between the engaged and disengaged positions and having a locking section, configured to bias the locking dogs into interference with the abutting surface in the engaged position, and an unlocking section, configured to allow free sliding of the piston within the screw in the disengaged position. An anti-jamming device for operating a critical flight control surface.

A method of controlling an overly determined actuator system that has a first number of actuators (α.sub.i) which is greater than a second number of the actuators needed to perform a predetermined physical task. The method includes: automatically controlling the first number of actuators by a control unit (CU) for jointly performing the predetermined physical task; repeatedly checking a functional state of the first number of actuators to detect an actuator failure of any one thereof; in case of any detected actuator failure, generating at least one emergency signal (EM) representative of an adapted physical task to be performed by a remaining number of the actuators. The emergency signal is generated based on kinematics of the actuator system, on known physical capacities at least of the remaining actuators, and optionally on a computational performance model of the actuator system. The adapted physical task includes activating each of the remaining actuators below a predetermined threshold of maximum physical load on a respective actuator and activating the ensemble of remaining actuators in a way to prevent further damage to the actuator system. An emergency control system and an aircraft are also provided.

An example aircraft disclosed herein includes a wing, a spoiler rotatably coupled to the wing, the spoiler movable between a cruise position and an upward position and between the cruise position and a droop position, and a spoiler actuation system coupled to a hydraulic system of the aircraft, the spoiler actuation system including a first piston and a second piston, a rack coupled between the first piston and the second piston, the rack movable between a first position and a second position, a pinion coupled to the rack, the pinion to rotate between a third position and a fourth position when the rack moves between the first position and the second position, a first crank arm coupled to the pinion, the first crank arm to rotate with the pinion between the third position and the fourth position, and a second crank arm coupled to the first crank arm and to the spoiler, the second crank arm to move the spoiler between the cruise position and the upward position when the first crank arm rotates between the third position and the fourth position.

An example aircraft disclosed herein includes a wing, a spoiler rotatably coupled to the wing, the spoiler movable between a cruise position and an upward position and between the cruise position and a droop position, and a spoiler actuation system coupled to a hydraulic system of the aircraft, the spoiler actuation system including a first piston and a second piston, a rack coupled between the first piston and the second piston, the rack movable between a first position and a second position, a pinion coupled to the rack, the pinion to rotate between a third position and a fourth position when the rack moves between the first position and the second position, a first crank arm coupled to the pinion, the first crank arm to rotate with the pinion between the third position and the fourth position, and a second crank arm coupled to the first crank arm and to the spoiler, the second crank arm to move the spoiler between the cruise position and the upward position when the first crank arm rotates between the third position and the fourth position.

A Stability and Control Augmentation System (“SCAS”) module includes a SCAS actuator. The SCAS actuator has a substantially cylindrical hydraulic chamber having a first and second regions. A piston is arranged for linear motion in first and second directions along an axis of the hydraulic chamber. The SCAS module also includes a valve system for controlling a flow of a hydraulic fluid into the hydraulic chamber. The valve system has: at least one supply line arranged to provide a first fluid flow path to the first region of the hydraulic chamber and/or a second fluid flow path to the second region of the hydraulic chamber, and a moveable valve member arranged to have a position between a first and second positions.

A Stability and Control Augmentation System (“SCAS”) module includes a SCAS actuator. The SCAS actuator has a substantially cylindrical hydraulic chamber having a first and second regions. A piston is arranged for linear motion in first and second directions along an axis of the hydraulic chamber. The SCAS module also includes a valve system for controlling a flow of a hydraulic fluid into the hydraulic chamber. The valve system has: at least one supply line arranged to provide a first fluid flow path to the first region of the hydraulic chamber and/or a second fluid flow path to the second region of the hydraulic chamber, and a moveable valve member arranged to have a position between a first and second positions.

A hydraulic system 300 for an aircraft including a backup hydraulic pressure source 216 to provide hydraulic pressure to a brake 222 in the event of a failure condition of a primary hydraulic brake pressure source. The hydraulic system 300 also includes a landing gear backup system to provide hydraulic pressure to enable extension and/or retraction of landing gear 100. The backup hydraulic pressure source 216 is arranged to provide hydraulic pressure to the landing gear backup system in the event of a failure condition of a primary landing gear hydraulic pressure source.

A hydraulic system 300 for an aircraft including a backup hydraulic pressure source 216 to provide hydraulic pressure to a brake 222 in the event of a failure condition of a primary hydraulic brake pressure source. The hydraulic system 300 also includes a landing gear backup system to provide hydraulic pressure to enable extension and/or retraction of landing gear 100. The backup hydraulic pressure source 216 is arranged to provide hydraulic pressure to the landing gear backup system in the event of a failure condition of a primary landing gear hydraulic pressure source.

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 actuator for moving a first component relative to a second component includes a first actuating mechanism secured to the first component and having a first motor, a first nut, and a first shaft secured to the first motor and the first nut such that the first nut is rotatable with the first motor. A second actuating mechanism is secured to the second component and has a second motor, a second nut, and a second shaft secured to the second motor and the second nut such that the second nut is rotatable with the second motor. A screw is threadably engaged with the first nut and the second nut such that rotation of at least one of the first motor and the second motor causes movement between the first and second nuts to move the second component relative to the first component.