A method for controlling a hybrid helicopter having at least one lifting rotor, at least one forward-movement propeller and an empennage provided with at least one moveable empennage surface. The method includes the following steps: using a main sensor to determine a current value of a rotor parameter conditioning a current power drawn by the lifting rotor, using an estimator to determine a current setpoint of the rotor parameter, adjusting a position of the moveable empennage surface using a deflection controller as a function of the current value and of current setpoint.

An aircraft provided with a rotary wing driven by a mechanical kinematic linkage, the aircraft having a power plant provided with at least one engine, the mechanical kinematic linkage comprising a free-wheel associated with the engine, the free-wheel comprising a driving part and a driven part, the driving part being connected by a mechanical connection to a working shaft of the associated engine and the driven part being connected kinematically to the rotary wing. A disengageable connection is arranged in parallel with the free-wheel in order to transmit mechanical power between the rotary wing and the engine on request, the power plant having a braking system comprising an engine brake of the engine.

A yaw control system for a helicopter having a tailboom includes one or more tail rotors rotatably coupled to the tailboom and a quiet mode controller. The quiet mode controller includes a noise monitoring module configured to monitor one or more flight parameters of the helicopter and a quiet mode command module configured to selectively switch the one or more tail rotors to a quiet mode based on the one or more flight parameters. The quiet mode command module is also configured to modify one or more operating parameters of the one or more tail rotors in the quiet mode to reduce noise emitted by the helicopter.

An exemplary anti-torque system for a rotorcraft includes a fan located inside of a channel that extends inside of a fuselage from an inlet proximate a forward end of the tail boom to an outlet at an aft end of the tail boom, the outlet is oriented to direct airflow from the channel onto a rudder coupled to a trailing edge of a vertical stabilizer.

An exemplary anti-torque system for a rotorcraft includes a fan located inside of a channel that extends inside of a fuselage from an inlet proximate a forward end of the tail boom to an outlet at an aft end of the tail boom, the outlet is oriented to direct airflow from the channel onto a rudder coupled to a trailing edge of a vertical stabilizer.

A method is provided for alerting a rotorcraft crew member of a potential collision of a rotor blade of the rotorcraft having a rotor shaft and a rotor azimuth. The method comprises estimating a total rotor flapping value associated with the rotor blade during an operating condition of the rotorcraft. The estimated total rotor flapping value is relative to the rotor shaft as a function of the rotor azimuth. The method also comprises comparing the estimated total rotor flapping value to a rotor flapping limit value during the operating condition of the rotorcraft. The method further comprises sending a warning signal to a warning device when the estimated total rotor flapping value lies outside of the rotor flapping limit value to alert the rotorcraft crew member of a potential collision of the rotor blade of the rotorcraft.

A method is provided for alerting a rotorcraft crew member of a potential collision of a rotor blade of the rotorcraft having a rotor shaft and a rotor azimuth. The method comprises estimating a total rotor flapping value associated with the rotor blade during an operating condition of the rotorcraft. The estimated total rotor flapping value is relative to the rotor shaft as a function of the rotor azimuth. The method also comprises comparing the estimated total rotor flapping value to a rotor flapping limit value during the operating condition of the rotorcraft. The method further comprises sending a warning signal to a warning device when the estimated total rotor flapping value lies outside of the rotor flapping limit value to alert the rotorcraft crew member of a potential collision of the rotor blade of the rotorcraft.

An aircraft rotor system including a hub having a hub axis about which the hub is configured to rotate; a plurality of rotor blades configured to extend from the hub and rotate about the hub axis, at least one of the rotor blades rotatable about a respective pitch change axis; wherein the hub is configured to be rotated about the hub axis only by the plurality of rotor blades. Another aspect includes a method of operating the rotor system.

An aircraft rotor system including a hub having a hub axis about which the hub is configured to rotate; a plurality of rotor blades configured to extend from the hub and rotate about the hub axis, at least one of the rotor blades rotatable about a respective pitch change axis; wherein the hub is configured to be rotated about the hub axis only by the plurality of rotor blades. Another aspect includes a method of operating the rotor system.

A method of fitting a single engine helicopter having a tail boom to avoid exhaust gases at the tail boom, the single engine helicopter comprising a longitudinally centrally positioned single engine and a corresponding symmetrically positioned exhaust manifold and symmetrically positioned rear tail boom, and the method includes securing to the exhaust manifold a curved and bent deflector exhaust nozzle, the deflector exhaust nozzle configured to receive exhaust from the single engine and direct the exhaust gases away from the tail boom. A single engine helicopter includes a longitudinally centrally positioned single engine and a corresponding symmetrically positioned exhaust manifold and a symmetrically positioned rear tail boom, the helicopter having a curved and bent deflector exhaust nozzle secured to the manifold, the deflector exhaust nozzle configured to receive exhaust gases from the single engine and direct the exhaust away from the tail boom.