A directional control system for a rotorcraft having a tail boom including a no-tail-rotor apparatus configured to control rotorcraft yaw using forced air ejected from the tail boom and a duct configured to deliver the forced air to the no-tail-rotor apparatus. The directional control system comprises a heat exchanger having air passages and fluid passages, the air passages in fluid communication with the duct, the fluid passages in heat exchange relationship with the air passages and configured for receiving a cooling fluid, and a forced air driver in fluid communication with the duct for driving the forced air through the duct to the no-tail-rotor apparatus. Methods of providing directional control in a rotorcraft are also discussed.

In some embodiments, an aircraft includes a fuselage having a forward portion and an aft portion. First and second ducted fans are supported by the forward portion of the fuselage. The first and second ducted fans are tiltable relative to the fuselage between a generally horizontal orientation, in a vertical takeoff and landing mode, and a generally vertical orientation, in a forward flight mode. A tailboom having an aft station extends from the aft portion of the fuselage. A cross-flow fan is disposed in the aft station of the tailboom and is operable to generate a pitch control moment.

A helicopter has a fuselage, a main rotor system connected to the fuselage and configured to rotate in a rotor direction, the main rotor system comprising a retreating rotor blade side and an opposing advancing rotor blade side, and a first wing extending from the fuselage on the retreating rotor blade side. The helicopter comprises no tail rotor system and comprises no counter-rotating rotor system coaxial with the main rotor system.

In one embodiment, a rotorcraft comprises a fuselage, a tail boom, a rotor system, and a centrifugal blower system. The centrifugal blower system comprises a centrifugal blower configured to generate thrust using an airflow, wherein the centrifugal blower is located within the tail boom. The centrifugal blower system also comprises a plurality of ducts configured to control the thrust generated by the centrifugal blower, wherein the plurality of ducts is located on a portion of the tail boom surrounding the centrifugal blower, and wherein the plurality of ducts comprises one or more adjustable ducts configured to vary a size of an associated duct opening.

In some embodiments, an aircraft includes a fuselage having a forward portion and an aft portion. First and second ducted fans are supported by the forward portion of the fuselage. The first and second ducted fans are tiltable relative to the fuselage between a generally horizontal orientation, in a vertical takeoff and landing mode, and a generally vertical orientation, in a forward flight mode. A tailboom having an aft station extends from the aft portion of the fuselage. A cross-flow fan is disposed in the aft station of the tailboom and is operable to generate a pitch control moment.

In some embodiments, a rotorcraft includes a fuselage, a tailboom, a drive system and a variable thrust cross-flow fan system. The cross-flow fan system includes a cross-flow fan assembly that is mechanically coupled to a drive shaft and operable to rotate with the drive shaft about a longitudinal axis. The cross-flow fan assembly includes first and second driver plates having a plurality of blades rotatably mounted therebetween. The blades are disposed radially outwardly from the longitudinal axis and have a generally circular path of travel when the cross-flow fan assembly rotates about the longitudinal axis. The blades are moveable between a plurality of pitch angle configurations. A control assembly is coupled to the blades. The control assembly is operable to change the pitch angle configuration of the blades to generate variable thrust at a substantially constant rotational speed of the cross-flow fan assembly.

The present invention relates to a device for controlling the yaw of an aviation device, such as a helicopter, said aviation device comprising a bearing structure and a rotating member connected to the bearing structure to be mobile in rotation, around an axis of rotation, relative to said bearing structure, wherein the rotating member comprises fixing means for fixing at least one blade, the yaw control device comprising a rotor and a stator which form, in combination, an electrical machine, wherein the bearing structure is connected to the first of this stator and this rotor, and wherein the rotating member is connected to the second of this stator and this rotor, wherein the electrical machine is suitable for generating an electromotive force applied to the rotating member.

The present disclosure is directed to a method for controlling rotors of a rotorcraft system comprising the steps of: receiving air velocity data, first and second rotors rotational angular velocity data, external air temperature data and rotorcraft altitude data by the control module; calculating air velocity over the plurality of blades based on the received data using the control module; calculating, based on the calculated air velocity, if one or more retreating blades of one of the first and second counterrotating rotors are generating insufficient lift; and sending one or more actuation signals from the control module to the electric motor and/or actuators of the other of the first and second counterrotating rotors to maintain a predetermined amount of lift.

A directional tail thrust system for a helicopter includes a tailboom defining an internal air passage. The aft portion of the internal air passage includes an aft diffuser. The directional tail thrust system also includes a fan in fluid communication with the aft diffuser and a vane array including vanes coupled to the aft diffuser and configured to receive air from the fan via the aft diffuser. The vanes are pivotable to switch the vane array between various modes including an anti-torque mode to produce anti-torque thrust, a forward thrust mode to produce forward thrust and a pro-torque mode to produce pro-torque thrust.

Apparatus and methods for controlling yaw of a rotorcraft in the event of one or both of low airspeed and engine failure are disclosed. A yaw propulsion provides a yaw moment at low speeds. The yaw propulsion device may be an air jet or a fan. A pneumatic fan may be driven by compressed air released into a channel surrounding an outer portion of the fan. The fan may be driven by hydraulic power. Power for the yaw propulsion device and other system may be provided by a hydraulic pump and/or generator engaging the rotor. Low speed yaw control may be provided by auxiliary rudders positioned within the stream tube of a prop. The auxiliary rudders may one or both of fold down and disengage from rudder controls when not in use.