An aircraft includes an airframe having an extending tail, a counter rotating, coaxial main rotor assembly disposed at the airframe including an upper rotor assembly and a lower rotor assembly and a translational thrust system positioned at the extending tail and providing translational thrust to the airframe. A flight control computer is configured to control a main rotor rotational speed of the upper and the lower rotor assemblies of the main rotor assembly as a function of airspeed of the aircraft. A method of operating an aircraft includes retrieving a threshold main rotor rotational speed of the dual coaxial main rotor assembly and calculating an actual main rotor rotational speed according to an environment of the aircraft. The actual main rotor rotational speed is maintained to remain at or below the threshold main rotor speed according to an airspeed of the aircraft.

An aircraft includes an airframe having an extending tail, a counter rotating, coaxial main rotor assembly disposed at the airframe including an upper rotor assembly and a lower rotor assembly and a translational thrust system positioned at the extending tail and providing translational thrust to the airframe. A flight control computer is configured to control a main rotor rotational speed of the upper and the lower rotor assemblies of the main rotor assembly as a function of airspeed of the aircraft. A method of operating an aircraft includes retrieving a threshold main rotor rotational speed of the dual coaxial main rotor assembly and calculating an actual main rotor rotational speed according to an environment of the aircraft. The actual main rotor rotational speed is maintained to remain at or below the threshold main rotor speed according to an airspeed of the aircraft.

An anti-torque rotor includes a mast rotatable about a first axis; a plurality of blades; an element slidable along the first axis, rotating integrally with the mast and operatively connected to the blades. The rotor also has a slidable control rod; a first bearing with a rotatable first ring, a second ring radially internal to the first ring and a plurality of first rolling bodies; a third ring slidable along the first axis and angularly fixed with respect to the first axis; and a locking element arranged in a first configuration, in which it prevents the relative rotation of the second and third rings and is movable from the first configuration to at least one emergency configuration, in which it renders the second ring free to rotate with respect to the third ring, when the first bearing is in a failure condition.

An anti-torque rotor includes a mast rotatable about a first axis; a plurality of blades; an element slidable along the first axis, rotating integrally with the mast and operatively connected to the blades. The rotor also has a slidable control rod; a first bearing with a rotatable first ring, a second ring radially internal to the first ring and a plurality of first rolling bodies; a third ring slidable along the first axis and angularly fixed with respect to the first axis; and a locking element arranged in a first configuration, in which it prevents the relative rotation of the second and third rings and is movable from the first configuration to at least one emergency configuration, in which it renders the second ring free to rotate with respect to the third ring, when the first bearing is in a failure condition.

A linear sensor module includes a fixed housing and a piston movable within the housing in response to an input. At least one biasing mechanism is operably coupled to the piston. A fly-by-wire input is associated with the piston and is operable to communicate the input to a control system.

A magnetorheological fluid clutch apparatus comprises an input rotor adapted to be coupled to a power input, the input rotor having a first set of at least one input shear surface, and a second set of at least one output shear surface. An output rotor is rotatably mounted about the input rotor for rotating about a common axis with the input rotor, the output rotor having a first set of at least one output shear surface, and a second set of at least one output shear surface, the first sets of the input rotor and the output rotor separated by at least a first annular space and forming a first transmission set, the second sets of the input rotor and the output rotor separated by at least a second annular space and forming a second transmission set. Magnetorheological fluid is in each of the annular spaces, the MR fluid configured to generate a variable amount of torque transmission between the sets of input rotor and output rotor when subjected to a magnetic field. A pair of electromagnets are configured to deliver a magnetic field through the MR fluid, the electromagnets configured to vary the strength of the magnetic field, whereby actuation of at least one of the pair of electromagnets results in torque transmission from the at least one input rotor to the output rotor.

A magnetorheological fluid clutch apparatus comprises an input rotor adapted to be coupled to a power input, the input rotor having a first set of at least one input shear surface, and a second set of at least one output shear surface. An output rotor is rotatably mounted about the input rotor for rotating about a common axis with the input rotor, the output rotor having a first set of at least one output shear surface, and a second set of at least one output shear surface, the first sets of the input rotor and the output rotor separated by at least a first annular space and forming a first transmission set, the second sets of the input rotor and the output rotor separated by at least a second annular space and forming a second transmission set. Magnetorheological fluid is in each of the annular spaces, the MR fluid configured to generate a variable amount of torque transmission between the sets of input rotor and output rotor when subjected to a magnetic field. A pair of electromagnets are configured to deliver a magnetic field through the MR fluid, the electromagnets configured to vary the strength of the magnetic field, whereby actuation of at least one of the pair of electromagnets results in torque transmission from the at least one input rotor to the output rotor.

An anti-torque rotor includes a mast rotatable about a first axis; a plurality of blades; an element slidable along the first axis, rotating integrally with the mast and operatively connected to the blades. The rotor also has a slidable control rod; a first bearing with a rotatable first ring, a second ring radially internal to the first ring and a plurality of first rolling bodies; a third ring slidable along the first axis and angularly fixed with respect to the first axis; and a locking element arranged in a first configuration, in which it prevents the relative rotation of the second and third rings and is movable from the first configuration to at least one emergency configuration, in which it renders the second ring free to rotate with respect to the third ring, when the first bearing is in a failure condition.

A pitch control device for a ducted tail rotor of a rotorcraft. The pitch control device comprises a control input member with a disc-shaped central component and at least two connecting arms that extend radially from the disc-shaped central component, wherein the disc-shaped central component is provided for being mounted to an associated pitch control shaft of the ducted tail rotor, and a control transfer member with a ring-shaped connector and at least two push rods that extend axially from the ring-shaped connector, wherein each one of the at least two push rods is provided for being coupled to an associated pitch lever of a rotor blade of the ducted tail rotor.

An aircraft includes an airframe with an upper portion and an extending tail, a counter-rotating, coaxial main rotor assembly disposed at the upper portion of the airframe, a translational thrust system, including a propeller, disposed at the extending tail of the airframe and a flight control system configured to control at least one of revolutions-per-minute (RPM) and pitch of the propeller of the translational thrust system in response to an input speed or acceleration command.