An electrically distributed yaw control system for a helicopter having a tailboom and a power system includes one or more tail rotors including a motor rotatably coupled to the tailboom and a power distribution unit. The power distribution unit includes a power management monitoring module configured to monitor one or more flight parameters of the helicopter and a power management command module configured to allocate power between the power system and the one or more tail rotor motors based on the one or more flight parameters of the helicopter.

According to one implementation of the present disclosure, a tail rotor system of a rotorcraft includes an electric motor, a swiveling actuator, a spindle, and a hub assembly. The hub assembly may be configured to position two or more blades. Also, in response to a control signal, the swiveling actuator may be configured to actuate swivel rotation of the spindle around a vertical axis such that the hub assembly turns from a first horizontal directional axis to a second horizontal directional axis.

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 anti-torque system for a rotorcraft includes a first tail fan assembly including a plurality of first fan blades, a second tail fan assembly including a plurality of second fan blades and a motor adapted to provide torque to the first and second fan blades. The first fan blades have a larger rotational inertia than the second fan blades. The second fan blades are adapted to experience a larger angular acceleration than the first fan blades in response to torque from the motor, thereby providing responsive yaw control for the rotorcraft.

Systems and methods include providing an aircraft with a tail rotor system having a tail rotor housing that forms a cambered airfoil between an upper cambered surface and a lower cambered surface of the tail rotor housing. The cambered airfoil design of the tail rotor housing is capable of providing sufficient lifting force of an aircraft to offload the tail rotor during forward flight, thereby eliminating the need for a traditional vertical stabilizer or fin. The tail rotor blades of the tail rotor system are disposed within an aperture in the tail rotor housing, which minimizes or preferably eliminates exposure of the tail rotor blades to edgewise airflow typically encountered during forward flight, thereby allowing rigid rotor hubs, both in-plane and out-of-plane, to be used in the tail rotor system while also reducing noise output of the tail rotor system.

Tail boom drive systems for helicopters are described which utilize a fan internal to the tail boom to provide yaw control, and an external propulsor to provide forward thrust. In one embodiment, the tail boom drive system includes a shaft, a fan, and a propulsor. The shaft is disposed lengthwise within an interior space of the tail boom, and the shaft has a first end and a second end. The fan is mechanically coupled coaxially to the shaft within the interior space between the first end and the second end, and the fan generates a variable airflow directed towards the second end that is ejected from the interior space substantially perpendicular to the tail boom. The propulsor is external to the tail boom and is mechanically coupled coaxially to the shaft at the second end, and the propulsor generates a variable thrust directed towards the first end.

The present invention includes an a plurality of first variable speed motors mounted on a tail boom of the helicopter; one or more fixed pitch blades attached to each of the plurality of first variable speed motors; and wherein a speed of one or more of the plurality of first variable speed motors is varied to provide an anti-torque thrust.

A hybrid propulsion engine for a rotorcraft includes a core turboshaft engine having a gas path and an output shaft that provides torque to a main rotor. A fan module is disposed relative to the core turboshaft engine and is coupled to the output shaft. The fan module has a bypass air path that is independent of the gas path. A thrust nozzle is configured to mix exhaust gases from the core turboshaft engine with bypass air from the fan module and to discharge the mixture to provide propulsive thrust. In a turboshaft configuration, the fan module is closed to prevent the flow of bypass air therethrough such that the thrust nozzle does not provide propulsive thrust. In a turboshaft and turbofan configuration, the fan module is open allowing the flow of bypass air therethrough such that the thrust nozzle provides propulsive thrust, thereby supplying propulsion compounding for the rotorcraft.

An exemplary anti-torque system for a helicopter includes two or more electric fans rotatably mounted on a tail boom, the two or more electric fans rotatable about a longitudinal axis of the tail boom.

According to one implementation, a rotating device includes at least one ring, at least one motor and a power transmission mechanism. The least one ring rotates in a circumference direction. The at least one ring includes no hub for housing a motor inside the at least one ring. The at least one motor generates power for rotating the at least one ring. The power transmission mechanism transmits the power to the at least one ring.