A rotor system is disclosed for a reactive drive rotary wing aircraft. Apparatus and methods are disclosed for maintaining the rigidity of the rotor and eliminating play between flight controls and the rotor by mounting swashplate actuators to a flange rigidly secured to the mast. Apparatus and methods are disclosed for thermal management of the rotor in order to avoid bearing failure or loss of bearing preload. Methods include modulating the temperature of oil pumped over one or more of the mast bearing, swashplate bearing, and spindle bearing. The temperature of air passively or actively drawn through rotor may also be modulated to maintain bearing temperature within a predetermined range. Structures for reducing pressure losses and drag on components due to air flow through the rotor are also disclosed. A rotor facilitating thermal management by oil and air flow is also disclosed.

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.

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. The generator may be used to charge a battery during autorotation or descending. 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.

A helicopter main rotor control system includes a trunnion head mountable to a rotatable helicopter mast wherein the trunnion head has a control bar pivot supported by the trunnion head and pivotal about an axis substantially at a right angle to the helicopter mast. A control bar extends through the control bar pivot at a right angle thereto, and a pair of opposing leaf hinges are pivotal about the control bar and centered about said trunnion head. Each leaf hinge has a hinge plate extending from the control bar and defines a rotor blade mount hole therethrough.

A rotorcraft consisting of a fuselage, a plurality of arms on which electric motors driving propellers are mounted, one or a plurality of pivoting rotor supports on which thrust generating rotors with one or a plurality of blades attach. The rotor supports are substantially vertical when the aircraft is flying vertically, hovering, or on the ground, and tilted with respect to the aircraft when the aircraft has a forward motion component. The rotors can be powered on the ground, in hover, or in vertical flight, and spin in autorotation in horizontal flight.

A system to prevent or limit resonance in a rotocraft. The system comprises an airframe, a rotor system having a natural frequency and including a rotor and a mast attached to the airframe, and a non-linear spring positioned between the rotor system and the airframe. The rotor system and the airframe are operable to move relative to each other as the rotor system begins to oscillate. The non-linear spring is configured to be deformed when the rotor system and the airframe move relative to each other such that the deformation of the non-linear spring causes the natural frequency of the rotor system to change. Also disclosed is a related method for preventing or limiting resonance in a rotorcraft.

A rotorcraft comprising of a fuselage, a plurality of arms on which electric motors driving propellers are mounted, one or a plurality of pivoting rotor supports on which thrust generating rotors with one or a plurality of blades attach. The rotor supports are substantially vertical when the aircraft is flying vertically, hovering, or on the ground, and tilted with respect to the aircraft when the aircraft has a forward motion component. The rotors are configured to be powered on the ground, in hover, or in vertical flight, and spin in autorotation in horizontal flight.

A vertical-takeoff-and-landing (VTOL) aircraft includes a plurality of navigation sensors and processing circuitry configured to implement a navigation system. The plurality of navigation sensors is configured to output navigation sensor data. The navigation system is configured to receive road map data, aviation map data, and navigation sensor data and execute an automated emergency landing control module. The automated emergency landing control module is configured to identify a plurality of candidate landing sites using the road map data, the aviation map data, and the navigation sensor data, and select a target landing site from among the plurality of candidate landing sites. Upon detection of an emergency condition, the automated emergency landing control module outputs the target landing site.