Abstract: An apparatus with rotor input detection includes: a first reactance element disposed at a rotor configured such that at least a part of the rotor rotates around a rotation axis, and disposed at the rotor such that reactance of the first reactance element varies depending on relative rotation between a first portion of the rotor and a second portion of the rotor; and a second reactance element disposed at the rotor such that reactance of the second reactance element varies depending on a contact or a force applied to a side surface of the rotor. The first and second reactance elements are configured to detect inputs of different areas of the rotor.

Abstract: A swashplate assembly includes: a mounting sleeve configured for coupling to and around an upper portion of a gearbox, wherein the mounting sleeve extends downwards from the upper portion of the gearbox; a tilt sleeve coupled to the mounting sleeve, wherein the tilt sleeve has a curved exterior surface; a non-rotating swashplate ring positioned around the tilt sleeve, wherein the non-rotating swashplate ring has a first set of pitch control connectors and an anti-rotation connector; a rotating swashplate ring rotatable about the non-rotating swashplate ring, wherein the rotating swashplate ring has a second set of pitch control connectors and a drive link connector; and a first bearing system mounted between the non-rotating swashplate ring and the rotating swashplate ring.

Abstract: One embodiment is an electric drive system for an aircraft including a motor, a gear box associated with the motor, and a cooling fan for drawing air into the unit across an electronic component to cool the electronic component and for expelling air into an oil cooler for cooling oil contained therein. The electric drive system further includes an oil distribution system for distributing oil cooled by the oil cooler to at least one motor and at least one gearbox, the distributed oil being used to cool the motor and the gearbox, a reservoir for collecting the distributed oil after it has been used to cool the motor and the gearbox, and at least one structural element for retaining the motor, gearbox, the cooling fan, the oil distribution system, and the reservoir together as a unit.

Abstract: A compact and unobtrusive rotor control mechanism is presented that provides collective and cyclic pitch change to both rotors of a coaxial rotor system as well as a differential collective pitch change to one or both rotors simultaneously.

Abstract: A gyroplane employing torque compensated main rotor and hybrid power train is disclosed. The invention incorporates a torque-compensated main rotor system with a common Collective pitch control, which can be driven transiently during flight to allow Vertical Take-Off, Landing and Hovering (VTOLH) flight operations. Torque compensation is via a coaxial counter-rotating (CACR) rotor system, or alternatively using a single rotor in conjunction with one or more electronically-controlled, fixed-pitch, thruster motors. The use of electric motors for lift and torque compensation facilitates electronic and potentially autonomous control of all phases of vertical flight.

Abstract: A rotorcraft swashplate assembly includes a rotationally fixed swashplate fixed against rotating with a rotorcraft rotor. The swashplate assembly also includes a rotatable swashplate coupled to the rotor to rotate with the rotor. The swashplate assembly also includes multiple pitch change links, each pitch change link coupled to a respective rotor blade and to the rotatable swashplate to rotate with the rotor. The swashplate assembly also includes an annular track coupled to the rotationally fixed swashplate and configured to support each pitch change link riding on the annular track as each pitch change link rotates with the rotor. The track includes multiple bearings upon which a pitch change link rides, and actuators that move the bearings changing a shape of the annular track and thereby the pitch of each rotor blade as each pitch change link rides on the annular track during rotation of the rotor blades.

Abstract: A rotor hub assembly that includes a yoke configured to attach blades thereto, a universal joint configured to attach to, and transmit forces between, a mast and the yoke, and an elastomeric member configured to attenuate vibrations transmitted from the universal joint to the mast.

Abstract: An aerial vehicle adapted for vertical takeoff and landing using a set of wing mounted thrust producing elements and a set of tail mounted rotors for takeoff and landing. An aerial vehicle which is adapted to vertical takeoff with the rotors in a rotated, take-off attitude then transitions to a horizontal flight path, with the rotors rotated to a typical horizontal configuration. The aerial vehicle uses different configurations of its wing mounted rotors and propellers to reduce drag in all flight modes.

Abstract: A wind turbine blade comprises a flexible external skin and an internal support structure, together defining an aerodynamic profile of the wind turbine blade. At least a portion of the internal support structure is adjustable to thereby vary the aerodynamic profile.

Abstract: The present invention relates to a rotor assembly where associated electric motors are configured to rotate the rotor, control the collective pitch of the rotor/assembly, and/or control the cyclic pitch of the rotor/assembly, by varying the relative rotational angle between two or more of the associated electric motors.

Abstract: An aircraft having a vertical takeoff and landing flight mode and a forward flight mode. The aircraft includes a fuselage and a dual tiltwing assembly having a vertical lift orientation and a forward thrust orientation relative to the fuselage. The dual tiltwing assembly includes a forward wing and an aft wing coupled together and to the fuselage by a quadrilateral linkage. A distributed propulsion system is coupled to the dual tiltwing assembly and includes a plurality of forward propulsion assemblies coupled to the forward wing and a plurality of aft propulsion assemblies coupled to the aft wing. A flight control system is operably associated with the distributed propulsion system and the dual tiltwing assembly. The flight control system is operable to independently control each of the propulsion assemblies and is operable to transition the dual tiltwing assembly between the vertical lift orientation and the forward thrust orientation.

Abstract: A propeller arrangement for an aircraft, and an aircraft having a propeller arrangement of said type, are specified. The propeller arrangement has a first propeller blade and a second propeller blade, and a propeller mount on which both the first propeller blade and the second propeller blade are mounted. The propeller arrangement furthermore has a drive shaft with a holding unit, and a first connecting unit. The first propeller blade is rotatable about a first axis of rotation and the second propeller blade is rotatable about a second axis of rotation. The propeller mount is pivotable about a pivot axis. The first connecting unit is coupled to the first propeller blade and to the holding unit, such that, in the event of a pivoting of the propeller mount about the pivot axis, the first propeller blade is set in rotational motion about the first axis of rotation.

Abstract: Aircraft autothrottle system, having a motor to impart rotational movement to a shaft extending from the motor. An actuator is connected to the shaft and to an attachment end of a throttle lever having a control end, opposite the attachment end. The actuator has bearings to apply thrust to a longitudinal surface of the shaft such that the actuator is translated longitudinally along the shaft surface in response to motor-imparted rotation of the shaft. The shaft surface being smoothly continuous and longitudinally unbroken along its elongation to allow the actuator to longitudinally slip along the shaft irrespective of any shaft rotation by the motor when the thrust force exceeds a linear force manually applied at the throttle lever. An electronic controller for the motor to move the throttle lever so the motor moves the actuator assembly along the shaft based on an engine parameter monitored by the controller.

Abstract: A method, apparatus, and system for charging an electrical storage system in a vehicle. The vehicle comprises a support frame, a propulsion, an electric storage system, an extendable structure, and a power management unit. The propulsion system, the electrical storage system, and the power management unit are physically coupled to the support frame. The electrical storage system supplies the electrical energy to the propulsion system. The group of thermoelectric modules physically is physically coupled to the extendable structure and generates a current in response to a heat being transferred through the group of modules. The power management unit is electrically coupled to the electrical storage system and the group of thermal thermoelectric modules and controls storing the electrical energy in the electrical storage system using the current from the group of thermoelectric modules and supplying the electrical energy to the propulsion system.

Abstract: An aerial vehicle adapted for vertical takeoff and landing using pivoting thrust producing elements for takeoff and landing. An aerial vehicle which is adapted to takeoff with thrust units providing vertical thrust and then transitioning to a horizontal flight path. An aerial vehicle with pivoting thrust units with propellers, wherein some or all of the propellers are able to be stowed and fully nested during forward flight. An aerial vehicle able to quickly alter its thrust. A quick reaction propeller system which alters the pitch of the propeller blades in response to changes in coning angle of the propeller.

Abstract: Aircraft autothrottle system, having a motor to impart rotational movement to a shaft extending from the motor. An actuator is connected to the shaft and to an attachment end of a throttle lever having a control end, opposite the attachment end. The actuator has bearings to apply thrust to a longitudinal surface of the shaft such that the actuator is translated longitudinally along the shaft surface in response to motor-imparted rotation of the shaft. The shaft surface being smoothly continuous and longitudinally unbroken along its elongation to allow the actuator to longitudinally slip along the shaft irrespective of any shaft rotation by the motor when the thrust force exceeds a linear force manually applied at the throttle lever. An electronic controller for the motor to move the throttle lever so the motor moves the actuator assembly along the shaft based on an engine parameter monitored by the controller.

Abstract: A rotor hub assembly that includes a yoke configured to attach blades thereto, a universal joint configured to attach to, and transmit forces between, a mast and the yoke, and an elastomeric member configured to attenuate vibrations transmitted from the universal joint to the mast.

Abstract: A thrust producing unit for producing thrust in a predetermined direction, comprising a shrouding and at least two rotor assemblies, wherein the shrouding defines an internal volume, and wherein a first rotor assembly of the at least two rotor assemblies defines a first rotor axis and a second rotor assembly of the at least two rotor assemblies defines a second rotor axis, the first and second rotor axes being one of: (i) coaxially arranged, and (ii) inclined by associated inclination angles with respect to the predetermined direction, the associated inclination angles being comprised in a range between ?60° and +60°, and preferably amounting to 0°, and wherein the first rotor assembly is arranged outside of the internal volume of the shrouding.

Abstract: A connector assembly to connect a swashplate and a rotor shaft or hub is provided. The connector assembly includes a mount configured to fixedly connect to the rotor shaft or hub, a sleeve pivotably attached to the mount, and a translating element translationally retained within the sleeve and configured to engage with the swashplate such that the swashplate and the rotor shaft or hub rotate at the same rotational speed.

Abstract: In a first aspect, there is a personal air vehicle including a body having a forward portion, a central portion and an aft portion; a first ducted fan supported by the forward portion of the body; a second ducted fan supported by the aft portion of the body; and third and fourth ducted fans supported by the left and right sides of the body and pivotable relative to the body. An aspect provides a method of flying the personal air vehicle.

Abstract: A rotor blade assembly includes a rotor blade comprising an inboard end and an outboard end. A composite yoke fitting made from a composite material is attached to the rotor blade. The composite yoke fitting includes an outboard portion inserted into the inboard end of the rotor blade, an inboard portion, and a flexure region about which the rotor blade is configured to flex. The inboard portion and the flexure region are outside the rotor blade.

Abstract: An aircraft having a vertical takeoff and landing flight mode and a forward flight mode. The aircraft includes a fuselage and a dual tiltwing assembly having a vertical lift orientation and a forward thrust orientation relative to the fuselage. The dual tiltwing assembly includes a forward wing and an aft wing coupled together and to the fuselage by a quadrilateral linkage. A distributed propulsion system is coupled to the dual tiltwing assembly and includes a plurality of forward propulsion assemblies coupled to the forward wing and a plurality of aft propulsion assemblies coupled to the aft wing. A flight control system is operably associated with the distributed propulsion system and the dual tiltwing assembly. The flight control system is operable to independently control each of the propulsion assemblies and is operable to transition the dual tiltwing assembly between the vertical lift orientation and the forward thrust orientation.

Abstract: A vectored thrust control module for an aircraft that includes a servo system that couples to the aircraft structure at an output shaft connection point. A thrust motor assembly is fully supported by the servo system and rotates a bladed component to provide thrust to the aircraft. Further, the thrust motor assembly is rigidly connected with the servo system to rotate together about a longitudinal axis thrust line with respect to the aircraft structure. The bladed component and the thrust motor assembly generate a line of thrust that extends through the connection point of the servo system to the aircraft structure.

Abstract: A swashplate of a blade pitch control assembly is provided including a metal component having one or more interfacing features. The metal component includes a hollow first cylinder having a first flange extending outwardly from a first end thereof and a second flange extending outwardly from a second end thereof. A sidewall extends between the first and second flanges such that a cavity is defined between the first flange, the second flange, and the sidewall. A plurality of connecting members is connected to a portion of the first flange and the second flange and is spaced about a periphery of the first cylinder. A tubular composite component is arranged at least partially within the cavity between adjacent pairs of the connecting members.

Abstract: An aircraft's two wings and joined thruster propellers or turbines serve as rotary wings in helicopter mode and as fixed wings in airplane mode. The thrusters along the wingspans or at the wing tips drive both rotary wing rotation and airplane flight. Large-angle controlled feathering about the pitch change axes of the left and right wings and thrusters allows them to rotate, relative to each other, between facing and thrusting forward in the same direction for airplane flight or facing and thrusting oppositely for helicopter flight. Optional controls include: helicopter cyclic and collective pitch; airplane roll by differential wing pitch; yaw by differential prop thrust; fuselage pitch by wing pitch change and prop thrust change interacting with an underslung craft e.g.; and fuselage yaw control independent of rotor rotation via a powered rotary mast coupling or a tail responsive to rotor downwash. A teetering rotor hub is a further option.

Abstract: Aerial vehicles may be operated with discrete sets of propellers, which may be selected for a specific purpose or on a specific basis. The discrete sets of propellers may be operated separately or in tandem with one another, and at varying power levels. For example, a set of propellers may be selected to optimize the thrust, lift, maneuverability or efficiency of an aerial vehicle based on a position or other operational characteristic of the aerial vehicle, or an environmental condition encountered by the aerial vehicle. At least one of the propellers may be statically or dynamically imbalanced, such that the propeller emits a predetermined sound during operation. A balanced propeller may be specifically modified to cause the aerial vehicle to emit the predetermined sound by changing one or more parameters of the balanced propeller and causing the balanced propeller to be statically or dynamically imbalanced.

Abstract: A hub system comprises at least one yoke, at least one shear bearing, and at least one mast adapter. The at least one mast adapter is configured to support the at least one yoke and the at least one shear bearing, and the at least one yoke has a flapping hinge that is non-coincident with a flapping hinge of the at least one shear bearing. Another hub system comprises a stacked yoke and a mast adapter. The mast adapter is configured to transfer rotation from a rotor mast to the hub system to rotate the hub system about a central axis of rotation. The mast adapter is further configured to support the stacked yoke such that each yoke in the stacked yoke is configured to accommodate at least some amount of rotation about an axis that is perpendicular to or about perpendicular to the central axis of rotation.

Abstract: A wind turbine system may be configured with at least one wind turbine having an exterior surface. A distribution pipe positioned between the exterior surface and a drag feature with the drag feature connected to the exterior surface via at least one attachment feature. At least one nozzle can continuously extend from the distribution pipe through the drag feature. A controller connected to the distribution pipe may selectively activate the at least one nozzle to eject compressed fluids from the turbine blade to modify a preexisting radial velocity of the at least one turbine blade.

Abstract: Aerial vehicles may be operated with discrete sets of propellers, which may be selected for a specific purpose or on a specific basis. The discrete sets of propellers may be operated separately or in tandem with one another, and at varying power levels. For example, a set of propellers may be selected to optimize the thrust, lift, maneuverability or efficiency of an aerial vehicle based on a position or other operational characteristic of the aerial vehicle, or an environmental condition encountered by the aerial vehicle. At least one of the propellers may be statically or dynamically imbalanced, such that the propeller emits a predetermined sound during operation. A balanced propeller may be specifically modified to cause the aerial vehicle to emit the predetermined sound by changing one or more parameters of the balanced propeller and causing the balanced propeller to be statically or dynamically imbalanced.

Abstract: A method for equalizing rolling moments at high advance ratios is disclosed including impelling an aircraft in a forward direction at an airspeed by means of a thrust source and rotating a rotor of the aircraft at an angular velocity with respect to the airspeed effective to cause a positive total lift on each blade due to air flow over the blades in the retreating direction when the blade is moving in the retreating direction. The rotor includes an even number of blades placed at equal angular intervals around the rotor hub. One or both of cyclic pitch and rotor angle of attack are adjusted such that a rolling moment of the retreating blade due to reverse air flow is between 0.3 and 0.7 times a rolling moment on the advancing blade due to lift.

Abstract: An aircraft includes a first rotor assembly, a second rotor assembly, and a rotor phase angle control system. The system includes a phase adjustor operably associated with the first rotor assembly and the second rotor assembly. The method includes sensing vibrations exerted on the aircraft and offsetting a phase angle of the first rotor assembly and the second rotor assembly to minimize the vibrations.

Abstract: A wind blade includes a self-supporting structural framework, having a span-wise member, a plurality of chord-wise members, a fabric skin, and at least one of a stiffener and a mechanical element. The plurality of chord-wise members is coupled to the span-wise member and each chord-wise member and the span-wise member maintains an aerodynamic contour of the wind blade. Further, the fabric skin is disposed over the self-supporting structural framework. The stiffener and/or the mechanical element are coupled to the self-supporting structural framework, and are operable to provide a relative movement to the self-supporting structural framework for adjusting the aerodynamic contour and provide pretension to the fabric skin.

Abstract: According to one embodiment, a flight control device includes a grip, a stick associated with the grip, and a gimbal. The stick defines a first axis. The gimbal includes a first platform, a second platform, a first electro- rheological elastomeric bearing, and a second electro-rheological elastomeric bearing. The first platform is coupled to the stick and configured to rotate on a second axis that is perpendicular to the first axis. The second platform is in mechanical communication with the first platform and configured to rotate on a third axis that is perpendicular to the second axis. The first electro-rheological elastomeric bearing defines the second axis, and the second electro-rheological elastomeric bearing defines the third axis. The first and second electro-rheological elastomeric bearing being configured to each have a variable stiffness.

Abstract: A system and method to tilt coaxial counter-rotating rotor hub assemblies relative to a fuselage. The system includes a first rotor hub assembly and a second rotor hub assembly spaced apart from the first hub assembly and carried by the fuselage. The method includes pivotally attaching the first rotor hub assembly and the second rotor hub assembly to a pivot joint and thereafter tilting the first rotor hub assembly and the second rotor hub assembly about the pivot joint with a driver.

Abstract: A rotor state sensor system is provided for use with a rotor including a hub, a hub arm and a blade coupled to the hub by the hub arm. The sensor system includes sensors disposed on the hub arm to define a first plane, which emit emissions and receive reflected emissions, and which generate a signal according to the received reflected emissions, reflector plates disposed on the blade which define a second plane at locations where the emissions from the sensors are incident on the reflector plates and from which the reflected emissions are reflected towards the sensors and a computing device which receives the signal from the sensors, determines relative orientations of the first and second planes according to the received signal and determines a condition of the rotor based on the determined relative orientations.

Abstract: Described embodiments include an unmanned aerial vehicle and a method. The unmanned aerial vehicle includes an airframe and a rotary wing system coupled with the airframe and configured to aerodynamically lift the vehicle in the air. The unmanned aerial vehicle includes a flight controller configured to control a movement of the vehicle while airborne. The unmanned aerial vehicle includes a cleansing controller configured to manage a removal of a surface contaminant from a selected portion of a surface of an external object using an airflow generated by the rotary wing system.

Abstract: A rotor blade assembly includes a rotor blade, a rotatable flap portion disposed along a span of the rotor blade. A rotary actuator is located inside the rotor blade and is operably connected to the flap portion to rotate the flap portion about a flap axis. A rotary-winged aircraft includes an airframe and a main rotor assembly operably connected to the airframe. The main rotor assembly includes a plurality of rotor blade assemblies rotatable about a rotor assembly axis. At least one rotor blade assembly of the plurality of rotor blade assemblies includes a rotor blade and a rotatable flap portion disposed along a span of the rotor blade. A rotary actuator located inside the rotor blade and is operably connected to the flap portion to rotate the flap portion about a flap axis. The rotary actuator is absent oil, grease or other fluid lubricant.

Abstract: A transmission mechanism for a remote-controlled model simulation helicopter includes a body frame which is orderly provided with a main rotor holder, a main rotor shaft, and a main reduction gear provided with a plurality of washout holes which are evenly distributed about an axis thereof. The body frame is provided with a swashplate module and a servo arrangement at a middle portion thereof. Since the main reduction gear is provided with washout holes and the introduction of internally installed swashplate module together with taking advantage of self structural features of the body frame, it enables the elimination of the commonly used swashplate guide board. The servo devices are provided in a same plane within the body frame and provide a triangular configuration, so that the structure is reasonable and the transmittance of motion is stable.

Abstract: Aerial vehicles may be equipped with collapsible lift propellers and thrust propellers. The collapsible lift propellers may include retractable tips that may pivot or rotate from a first orientation substantially co-aligned with a main body of the collapsible lift propellers during ordinary operations and a second orientation substantially transverse to the main body of the collapsible lift propellers when rotation of the collapsible lift propellers is stopped. The collapsible lift propellers may further include biasing elements, e.g., springs for biasing the retractable tips into the second orientation, and mechanical stops for inhibiting the pivoting or rotation of the retractable tips beyond the first orientation.

Abstract: A hover-capable aircraft having propulsion means; at least one rotor; transmission means for transmitting power from the propulsion means to the rotor and lubricated with a lubricant; a heat exchanger, which receives the heated lubricant from the transmission means and feeds the cooled lubricant back to the transmission means; and a fan for producing airflow through the heat exchanger to cool the lubricant, and which has an impeller with blades, and an exhaust pipe for expelling the hot air produced by cooling the lubricant; at least one portion of the wall of the exhaust pipe has dissipating means designed to selectively absorb pressure waves in a given frequency band related to the rotation speed of the impeller and to the number of blades of the impeller.

Abstract: 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. Methods are disclosed for 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. Surfaces interfacing between the swashplate and the mast and between control rods and the swashplate or pitch horn may bear a solid lubricant layer.

Abstract: A rotor system of a reactive drive rotary wing maintains rigidity and stiffness and resists slack and backlash by mounting swashplate actuators to a flange rigidly secured to the mast, and may be monolithic therewith. A mast tilt actuator and a mast pivot may secure to the mast flange, with vibration suppressors. A shroud may provide a sealed fluid path for airflow therethrough encircling portions of the rotor hub and restricting airflow between the rotor hub and shroud. A rotor cavity, in fluid communication with blade ducts (hollow portions of the blade spars), and either or both contoured to reduce pressure losses, may assist in temperature control, and may feed into tip jets on the blades.

Abstract: According to one embodiment, a bearing is situated between a pitch link and a swashplate or a hub. The bearing comprises an outer housing having a first opening therethrough, an elastomeric bearing adjacent the housing inside the first opening and having a second opening therethrough, and an inner housing adjacent the elastomeric bearing inside the second opening and having a third opening therethrough. The inner housing comprising a first inner surface and a second inner surface defining the third opening. A first member is adjacent the first inner surface inside the third opening having a fourth opening therethrough. A second member is adjacent the second inner surface inside the third opening having a fifth opening therethrough coaxial with the fourth opening.

Abstract: A method and apparatus for reducing flapping loads imposed on a rotor are disclosed. The method may include flying a rotorcraft comprising an airframe, a rotor, a mast extending to connect the rotor to the airframe, a tilt mechanism, at least one sensor, and a computer system. The computer system may obtain in real time, from the at least one sensor, data characterizing at least one flapping load experienced by the rotor during the flying. Using the data, the computer system may issue at least one command to the tilt mechanism. In response to the command, the tilt mechanism may reorient the mast with respect to the airframe. This reorienting may lower the flapping load experienced by the rotor.

Abstract: 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. Methods are disclosed for 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. Surfaces interfacing between the swashplate and the mast and between control rods and the swashplate or pitch horn may bear a solid lubricant layer.

Abstract: A method and apparatus for optimized crossing of natural frequencies of a rotorcraft rotor are disclosed. The method may include flying a rotorcraft comprising an airframe, a rotor, a mast extending to connect the rotor to the airframe, a tilt mechanism, and a computer system. The computer system may identify during the flying, an impending crossing of a natural frequency of the rotor. In preparation for the crossing, the computer system may issue at least one command to the tilt mechanism. In response to the command, the tilt mechanism may reorient the mast with respect to the airframe. That reorientation quickly results in a change to the rotational speed of the rotor, moving it quickly across the natural frequency. The reorientation may also prevent the rotor from experiencing any significantly deleterious flapping loads during the crossing of the natural frequency.

Abstract: A rotor (10) provided with a hub (11) and a plurality of blades (12), said rotor (10) including a mast (15) secured to said hub (11) and protection means (30) for providing protection against lightning. The protection means (30) comprise rotary electric current conduction means (32) constrained to rotate with said mast (15) and connected to each of the blades (12) via a respective first electrical connection member (31), said protection means (30) including non-rotary electric current conduction means (33) facing said rotary conduction means (32) while not being constrained to rotate with said mast (15), said protection means (30) including electrical connection trigger means (35), said non-rotary conduction means (33) being provided with a second electrical connection member (34) suitable for being electrically connected to a target member (38) external to said rotor (10).

Abstract: A rotor assembly includes a rotor shaft rotatable about a rotor axis and a plurality of rotor blades operably connected to the rotor shaft. A rotor control assembly has a plurality of substantially concentric control tubes extending through the rotor shaft. Each control tube of the plurality of control tubes is operably connected to a rotor blade of the plurality of rotor blades such that movement of one or more of the control tubes of the plurality of control tubes along the rotor axis effects a pitch change in one or more rotor blades of the plurality of rotor blades. A method of controlling pitch of a plurality of rotor blades of a rotor assembly includes locating a plurality of concentric control tubes inside of a rotor shaft of the rotor assembly capable of changing a pitch of one or more of the rotor blades.

Abstract: Methods and apparatus for vertical or short takeoff and landing. In one embodiment, the apparatus comprises two or more counter driven rings with one or more airfoils attached. In one variant, there is an upper ring and a lower ring, each with multiple airfoils attached. In one variant, lift is generated largely via ambient air currents, allowing for long term on-station operation of the device.

Abstract: According to one embodiment, a method for determining a position of a rotor blade includes receiving a plurality of measurements from a plurality of magneto-resistive sensors and determining a position of the at least one magnet based on the received plurality of measurements. In this example, one of the plurality of magneto-resistive sensors and the at least one magnet moves with a rotor blade.