A stability and control augmentation system (SCAS) actuator is operable for actuating a flight control surface of an aircraft. The SCAS actuator includes an actuator housing having a first aperture, a second aperture and a hydraulic chamber therebetween. A piston extends through the actuator housing. Fluid inlets are in fluid communication with regions of the hydraulic chamber. A first end portion of the piston is arranged to slide through the first aperture without a seal between the first end portion and the first aperture. A second end portion of the piston is arranged to slide through the second aperture without a seal between the second end portion and the second aperture. An intermediate portion of the piston is arranged to slide in the hydraulic chamber without a seal between the intermediate portion and the hydraulic chamber.

There is provided a control module for a hydraulic system. The module comprises a tank and a plurality of valves. The tank is configured to store hydraulic fluid and is substantially cylindrical. The plurality of valves fluidly connect with the tank and are configured to control distribution of hydraulic fluid from the tank to one or more components of the system. The plurality of valves are spaced around a circumference of the tank. One or more passages fluidly connect the tank with at least one of the plurality of valves and/or a first of the plurality of valves with a second of the plurality of valves.

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.

An apparatus for damping an actuator includes an inerter. The inerter includes a first terminal and a second terminal movable relative to one another along an inerter axis and configured to be mutually exclusively coupled to a support structure and a movable device actuated by an actuator. The inerter further includes a rod coupled to and movable with the first terminal and a threaded shaft coupled to and movable with the second terminal. The inerter further includes a flywheel having a flywheel annulus coupled to one of the rod and the threaded shaft. The flywheel is configured to rotate in proportion to axial acceleration of the rod relative to the threaded shaft in correspondence with actuation of the movable device by the actuator.

An apparatus for damping an actuator includes an inerter. The inerter includes a first terminal and a second terminal movable relative to one another along an inerter axis and configured to be mutually exclusively coupled to a support structure and a movable device actuated by an actuator. The inerter further includes a rod coupled to and movable with the first terminal and a threaded shaft coupled to and movable with the second terminal. The inerter further includes a flywheel having a flywheel annulus coupled to one of the rod and the threaded shaft. The flywheel is configured to rotate in proportion to axial acceleration of the rod relative to the threaded shaft in correspondence with actuation of the movable device by the actuator.

An automatic engine driven pump (EDP) depressurization system for an aircraft is disclosed. The aircraft includes at least two EDPs driven by a main engine for converting mechanical power provided by the main engine into hydraulic power for distribution by a hydraulic system. The EDP depressurization system includes a depressurization device corresponding to each of the at least two EDPs and a control module. The depressurization devices are each energized to depressurize a respective EDP. The control module is in signal communication with each of the depressurization devices. The control module includes control logic for automatically generating a depressurization signal that energizes one of the depressurization devices based on a plurality of operational conditions of the aircraft.

The present disclosure provides an aircraft thermal management system. The aircraft thermal management system includes a first hydraulic system for circulating a first hydraulic fluid, a second hydraulic system for circulating a second hydraulic fluid, and a third hydraulic system for circulating a third hydraulic fluid. The aircraft thermal management system also includes a controller configured to: (i) determine a temperature of the first hydraulic fluid, a temperature of the second hydraulic fluid, and a temperature of the third hydraulic fluid, and (ii) based on the determined temperature of the first hydraulic fluid, utilize the second hydraulic fluid and/or the third hydraulic fluid to modify an operational temperature of the first hydraulic fluid.

A method is provided for verifying proper operation of a left elevator tab disposed at an end portion of a left elevator of an aircraft and a right elevator tab disposed at an end portion of a right elevator of the aircraft. Because proper operation of the elevator tabs cannot be directly verified by existing aircraft instrument, the operation of the elevator tabs can be indirectly verified by analyzing flight data of the aircraft. After identification of a verification event, in which the elevator tabs move relative to the elevators, the positions of the left elevator and right elevator can be measured, and differences in the positions of the left elevator and right elevator can indicate proper operation of the left and right elevator tabs.