A bidirectional aircraft rotor for a rotorcraft tail rotor. The rotorcraft tail rotor uses a hub and a first tail rotor blade affixed to the hub. A pitch of the first tail rotor blade is fixed, and a profile of a leading edge of the first tail rotor blade is identical to a profile of a trailing edge of the first tail rotor blade. The tail rotor is driven by a torque source, such as an electric motor or an engine. The tail rotor uses variable RPM and reversible rotational direction to provide rotorcraft with yaw control.

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.

An improved vehicle with superior performance and reliability. The vehicle, such as an unmanned aerial vehicle, is capable of vertical takeoff and landing, uses three swashless, variable-pitch vertical lift main rotors with a yaw tail rotor system. Two rear main rotors are optionally tiltrotors, which pivot to increase forward speed without the increased coefficient of drag inherent in tilting the entire vehicle. The three main rotors are positioned in an equilateral triangular configuration, improving balance, increasing load-bearing strength, and making it more compact in size. Movements are controlled through changes in pitch of the rotors, allowing the motors to maintain constant governed rotations per minute, maximizing drivetrain efficiency. Vehicle configurations disclosed herein allow for smaller vehicle size with greater performance than prior art vehicles.

A method of providing an anti-torque force in a rotorcraft with an anti-torque system comprised of a primary ducted tail rotor system mechanically connected to an engine, and a secondary ducted tail rotor system electrically connected to an electric power supply. The method includes receiving an indication of a change in the operating condition of the anti-torque system based upon a change in a rotorcraft condition input, a feedback input associated with a primary ducted tail rotor system and/or a secondary ducted tail rotor system, and/or a pilot input; responsive to the indication of the change, determining, by a control system, an anti-torque control input including at least a secondary output command for controlling the secondary ducted tail rotor system; and transmitting the secondary output command to the secondary ducted tail rotor system to energize at least one ducted tail rotor assembly therein to provide the second anti-torque force.

A diverter duct for a propeller includes a second duct element having a semi-annular wedge shape, which is pivotably coupled to the first duct element, a first drive structure configured to drive a pivoting of the second duct element relative to the first duct element and a second drive structure configured to drive a rotation of the first and second duct elements about an axis of rotation of the propeller.

A yaw control system of an aircraft includes an aircraft having an airframe extending along a longitudinal axis, a coaxial contra-rotating main rotor system rotatable about a first axis, and a rotor system rotatable about a second axis to move air between a first side of the airframe and a second, opposite side of the airframe. The first side and the second side are disposed on opposing sides of the longitudinal axis. The yaw control provided by operation of the rotor system is supplemental to the yaw control provided by the coaxial contra-rotating main rotor system.

Systems and methods include providing a helicopter, with a fuselage, a tail boom extending from the fuselage, a main rotor system, and a tail rotor assembly disposed on an aft end of the tail boom. The tail rotor assembly includes a tail rotor housing, at least one normal ducted fan that generate anti-torque thrust to prevent rotation of the fuselage, and at least one canted ducted fan configured to generate both anti-torque thrust to prevent of the fuselage and lift to the tail boom in order to control the pitch of the helicopter. The canted ducted fans generate sufficient lift to prevent a nose-up orientation of the helicopter when the center of gravity of the helicopter is shifted rearward behind the main rotor system, while the normal ducted fans maintain sufficient anti-torque thrust to prevent rotation of the fuselage when the main rotor is operated.

A fuselage arranged within a fuselage outer shell; at least one main rotor located on top of the fuselage; at least one engine provided for driving the at least one main rotor; and at least one energy source storage unit comprising at least one energy source configured to provide energy for powering the at least one engine for driving the at least one main rotor; wherein the at least one energy source storage unit is arranged outside the fuselage outer shell; and wherein the fuselage and the fuselage outer shell form in vicinity of the at least one energy source storage unit a crashable structure configured to be crashable in an emergency landing at least for limiting effects of impact on the at least one energy source storage unit.

A system and method for slowing the rotation of a rotor using, for example, rotor brake system for a rotorcraft comprises: one or more generators connected to a main rotor gearbox; an electric distributed anti-torque system mounted on a tail boom of the rotorcraft comprising two or more electric motors connected to the one or more generators, wherein the two or more electric motors are connected to one or more blades; and wherein a rotation of the rotor is slowed by placing a drive load on the main rotor gearbox with the one or more generators to bleed the mechanical power from rotor into electrical power via the two or more electric motors, wherein the electric distributed anti-torque system generates thrust in opposing directions.

Systems and methods include providing an aircraft with a fuselage, a tail boom or empennage extending from the fuselage, a main rotor, a tail rotor, and at least one counter torque device. The counter torque device provides counter torque to the fuselage to prevent rotation of fuselage when the main rotor is operated, particularly in right sideward flight (RSF) for conventional helicopters with a counter-clockwise rotating (when viewed from above the helicopter) main rotor.