Abstract: There is described a method and system for in-flight start of an engine. The method comprises rotating a propeller; generating electrical power at an electric generator embedded inside a propeller hub from rotation of the propeller; transmitting the electrical power from the electric generator to an engine starter mounted on a core of the engine via an electric power link; and driving the engine with the engine starter to a sufficient speed while providing fuel to a combustor to light the engine to achieve self-sustaining operation of the engine.

Abstract: There is described a method and system for in-flight start of an engine. The method comprises rotating a propeller; generating electrical power at an electric generator embedded inside a propeller hub from rotation of the propeller; transmitting the electrical power from the electric generator to an engine starter mounted on a core of the engine via an electric power link; and driving the engine with the engine starter to a sufficient speed while providing fuel to a combustor to light the engine to achieve self-sustaining operation of the engine.

Abstract: There is described a method and system for in-flight start of an engine. The method comprises rotating a propeller; generating electrical power at an electric generator embedded inside a propeller hub from rotation of the propeller; transmitting the electrical power from the electric generator to an engine starter mounted on a core of the engine via an electric power link; and driving the engine with the engine starter to a sufficient speed while providing fuel to a combustor to light the engine to achieve self-sustaining operation of the engine.

Abstract: An aircraft control system includes a propeller shaft assembly. Also included is first rotor operatively coupled to the propeller shaft assembly, the first rotor having a first plurality of blades mounted thereto, the first blades disposed at a substantially identical nominal pitch during rotation of the first rotor, the first rotor rotatable in a first direction. Further included is a second rotor operatively coupled to the propeller shaft assembly and rotatable in a second direction, the second rotor having a second plurality of blades mounted thereto, wherein a pitch of the second blades cyclically changes during rotation of the second rotor, the first rotor and the second rotor disposed and rotated proximate a fixed wing of an aircraft about a common axis extending parallel to a longitudinal axis of the aircraft, cyclically changing the pitch of the second plurality of blades generating a moment for controlling the aircraft.

Abstract: There is described a method and system for in-flight start of an engine. The method comprises rotating a propeller; generating electrical power at an electric generator embedded inside a propeller hub from rotation of the propeller; transmitting the electrical power from the electric generator to an engine starter mounted on a core of the engine via an electric power link; and driving the engine with the engine starter to a sufficient speed while providing fuel to a combustor to light the engine to achieve self-sustaining operation of the engine.

Abstract: There is described a method and system for in-flight start of an engine. The method comprises rotating a propeller; generating electrical power at an electric generator embedded inside a propeller hub from rotation of the propeller; transmitting the electrical power from the electric generator to an engine starter mounted on a core of the engine via an electric power link; and driving the engine with the engine starter to a sufficient speed while providing fuel to a combustor to light the engine to achieve self-sustaining operation of the engine.

Abstract: A propeller assembly is provided including a plurality of blades arranged in diametrically opposed pairs. Each of the plurality of blades has an electrical deicer located thereon. The propeller assembly also includes a slip ring, and a stationary brush arranged in contact with the slip ring. The brush is configured to transfer electrical power from a power source to the slip ring. A movable portion of an actuator is configured to sequentially couple the electrical deicers of each pair of blades to the rotating slip ring.

Abstract: A power generation unit for generating electric power within a rotating reference frame includes a generator and a gear assembly. The generator has a plurality of first generator parts disposed concentrically with and radially outward from a plurality of second generator parts. The gear assembly is rotatably attached to the second generator parts and configured to allow relative rotation between the first and second generator parts caused by a single rotating component. The generator and the gear assembly are axially disposed along a common rotational axis.

Abstract: A method of controlling a Counter-Rotating Open-Rotor (CROR) includes mechanically linking a pitch change system of a first rotor with a pitch change system of a second rotor and commanding a Blade Angle (Beta1 commanded) of the first rotor such that a Blade Angle (Beta2 Actual) of the second rotor is a function of the commanded Blade Angle (Beta1 commanded) to provide a linear relationship between an actual Blade angle (Beta1 Actual) and Beta1 commanded of the first rotor and a non-linear relationship between Beta2 Actual and Beta1 commanded.

Abstract: A wind turbine blade assembly comprises a rotatable hub, a blade secured to the hub, and a pitch system. The pitch system is disposed to rotate the blade with respect to the hub about a pitch axis not extending through an aerodynamic centroid of the blade. The pitch system comprises a hydraulic cylinder pitch actuator and a relief valve. The hydraulic cylinder pitch actuator has first and second pressure chambers. The relief valve is configured to aerodynamically unload the blade by equilibrating the first and second pressure chambers in response to a pressure differential between the first and second pressure chambers exceeding a critical threshold corresponding to a pre-strain blade twist.

Abstract: An aircraft control system includes a propeller shaft assembly. Also included is first rotor operatively coupled to the propeller shaft assembly, the first rotor having a first plurality of blades mounted thereto, the first blades disposed at a substantially identical nominal pitch during rotation of the first rotor, the first rotor rotatable in a first direction. Further included is a second rotor operatively coupled to the propeller shaft assembly and rotatable in a second direction, the second rotor having a second plurality of blades mounted thereto, wherein a pitch of the second blades cyclically changes during rotation of the second rotor, the first rotor and the second rotor disposed and rotated proximate a fixed wing of an aircraft about a common axis extending parallel to a longitudinal axis of the aircraft, cyclically changing the pitch of the second plurality of blades generating a moment for controlling the aircraft.

Abstract: An aircraft control system includes a co-axial, counter-rotating propeller shaft assembly. Also included is a first rotor operatively coupled to the propeller shaft assembly, the first rotor having a first plurality of blades mounted thereto, wherein the first plurality of blades are disposed at a substantially identical nominal pitch during rotation of the first rotor. Further included is a second rotor operatively coupled to the propeller shaft assembly, the second rotor having a second plurality of blades mounted thereto, wherein a pitch of the second plurality of blades is configured to cyclically change during rotation of the second rotor.

Abstract: A propeller balancing device includes at least one stationary outer disc and a drive wheel arranged adjacent to the outer disc. The drive wheel includes magnets arranged at the periphery. A balancing weight is arranged in a groove formed in one of the outer disc or the drive wheel. A propeller including the propeller balancing device and a method of balancing a propeller are also disclosed.

Abstract: A propulsion system and related methods are disclosed. A propulsion system may have a propulsor, an energy conversion system, an energy storage system that stores electrical energy, and a turbine. The propulsor may be in electrical communication with the energy conversion system, and the energy conversion system may receive electrical energy from the turbine or the energy storage system and deliver it to the propulsor. In this manner, a vehicle may be propelled by the propulsor even when the turbine is not operating.

Abstract: A power generation unit for generating electric power within a rotating reference frame includes a generator and a gear assembly. The generator has a plurality of first generator parts disposed concentrically with and radially outward from a plurality of second generator parts. The gear assembly is rotatably attached to the second generator parts and configured to allow relative rotation between the first and second generator parts caused by a single rotating component. The generator and the gear assembly are axially disposed along a common rotational axis.

Abstract: A pitchlock system includes a ballscrew screw mounted along an axis of rotation of an actuator, the ballscrew screw has an internal ballscrew bore; a pitchlock nut mounted about the ballscrew screw, the pitchlock nut including an internal pitchlock nut thread; a ballscrew ballnut mounted about the ballscrew screw and axially adjacent the pitchlock nut; a pitchlock actuation rod mounted axially within the internal ballscrew bore, the pitchlock actuation rod having an internal pitchlock actuation bore and a ball bearing aperture for receiving multiple ball bearings; a pitchlock retainer pin mounted axially within the internal pitchlock actuation bore; and a belleville spring which biases the ballscrew screw towards an axially fixed surface of the actuator in a pitchlock position, the ballscrew screw being movable between an operational position and the pitchlock position.

Abstract: There is described a method and system for in-flight start of an engine. The method comprises rotating a propeller; generating electrical power at an electric generator embedded inside a propeller hub from rotation of the propeller; transmitting the electrical power from the electric generator to an engine starter mounted on a core of the engine via an electric power link; and driving the engine with the engine starter to a sufficient speed while providing fuel to a combustor to light the engine to achieve self-sustaining operation of the engine.

Abstract: A propulsion system has a gas turbine engine optimized to operate at a single operating condition corresponding to a maximum continuous power output of the gas turbine engine, an electric motor system, an electric machine rotatably attached to the gas turbine engine and electrically connected to the electric motor system, and an energy storage system having bi-directional electrical connections with the electric motor system and the electric machine. A method of operating the propulsion system including operating the gas turbine engine for a first period of time to provide electric power to the electric motor system and to recharge the energy storage system, turning off the gas turbine for a second period of time, and discharging the energy storage system to operate the electric motor system during the second period of time.

Abstract: A counter-rotating propeller system comprises a cyclic pitch system connected to a first plurality of propeller blades and a variable pitch system connected to a second plurality of propeller blades. The first plurality of propeller blades and the second plurality of propeller blades are configured to rotate about a common axis.

Abstract: A method of controlling a Counter-Rotating Open-Rotor (CROR) includes measuring a speed of a first rotor and deriving a speed of a second rotor and controlling a pitch of the first rotor and the second rotor.