A SCAS module includes one or more SCAS actuators wherein each SCAS actuator comprises a piston arranged for linear motion within a hydraulic chamber in response to a flow of hydraulic fluid metered by a valve. The piston comprises a flexible rod or quill for providing a linear output along the first axis, the flexible rod or quill being mounted internally within an annular portion of the piston so that a space is defined around the flexible rod or quill. The flexible rod or quill is capable of deforming into the surrounding space in order to accommodate movement of the flexible rod or quill.

A SCAS module includes one or more SCAS actuators wherein each SCAS actuator comprises a piston arranged for linear motion within a hydraulic chamber in response to a flow of hydraulic fluid metered by a valve. The piston comprises a flexible rod or quill for providing a linear output along the first axis, the flexible rod or quill being mounted internally within an annular portion of the piston so that a space is defined around the flexible rod or quill. The flexible rod or quill is capable of deforming into the surrounding space in order to accommodate movement of the flexible rod or quill.

An aircraft control comprises a mobile pedal and comprises a cylinder coupled to the pedal such that a displacement of the pedal according to at least a first direction reduces the volume of a first chamber of the cylinder. A control device comprises a fluid type bus system connecting two aircraft controls. Additionally, an aircraft is equipped with such a control device.

An aircraft control comprises a mobile pedal and comprises a cylinder coupled to the pedal such that a displacement of the pedal according to at least a first direction reduces the volume of a first chamber of the cylinder. A control device comprises a fluid type bus system connecting two aircraft controls. Additionally, an aircraft is equipped with such a control device.

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.

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.

A hydrostatic automatic flight servo system is provided. The automatic flight servo system includes a manifold that defines a first fluid chamber, and a hydraulic fluid is received in the first fluid chamber. The first fluid chamber includes a first bellows and a second bellows. The automatic flight servo system includes a stick received at least partially within the manifold and pivotally coupled to the manifold. The stick includes a control arm fixedly coupled to the first bellows, and the stick is to receive an input. The automatic flight servo system includes a flight output system pivotally coupled to the manifold. The flight output system includes a second control arm received at least partially within the manifold and coupled to the second bellows such that the pivotal movement of the stick pivots the flight output system relative to the manifold.

According to one embodiment, a pilot assistance system includes a trim assembly and a trim assembly control system. The trim assembly is operable to communicate with a pilot control device and operable to apply a force against the pilot control device in resistance of a command received from a pilot via the pilot control device. The trim assembly control system is in communication with the trim assembly, configured to identify a first pilot control device position relative to a reference pilot control device position, and configured to instruct the trim assembly to apply a cueing force against the pilot control device if the pilot control device is positioned proximate to the first pilot control device position.

According to one embodiment, a pilot assistance system includes a trim assembly and a trim assembly control system. The trim assembly is operable to communicate with a pilot control device and operable to apply a force against the pilot control device in resistance of a command received from a pilot via the pilot control device. The trim assembly control system is in communication with the trim assembly, configured to identify a first pilot control device position relative to a reference pilot control device position, and configured to instruct the trim assembly to apply a cueing force against the pilot control device if the pilot control device is positioned proximate to the first pilot control device position.

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.