According to one implementation, a rotating device includes at least one ring, at least one motor and a power transmission mechanism. The least one ring rotates in a circumference direction. The at least one ring includes no hub for housing a motor inside the at least one ring. The at least one motor generates power for rotating the at least one ring. The power transmission mechanism transmits the power to the at least one ring.

An exemplary aircraft includes a turbine engine having a gas generator spool and a power spool, the power spool operational to drive a rotor, a first generator coupled to the gas generator spool, and a controller operable to increase a load on the gas generator spool when the gas generator spool is on a speed limit thereby increasing a speed limit margin in order to increase power available from the turbine engine.

An exemplary aircraft includes a turbine engine having a gas generator spool and a power spool, the power spool operational to drive a rotor, a first generator coupled to the gas generator spool, and a controller operable to increase a load on the gas generator spool when the gas generator spool is on a speed limit thereby increasing a speed limit margin in order to increase power available from the turbine engine.

An exemplary anti-torque system for a rotorcraft includes a fan located inside of a channel that extends inside of a fuselage from an inlet proximate a forward end of the tail boom to an outlet at an aft end of the tail boom, the outlet is oriented to direct airflow from the channel onto a rudder coupled to a trailing edge of a vertical stabilizer.

An exemplary anti-torque system for a rotorcraft includes a fan located inside of a channel that extends inside of a fuselage from an inlet proximate a forward end of the tail boom to an outlet at an aft end of the tail boom, the outlet is oriented to direct airflow from the channel onto a rudder coupled to a trailing edge of a vertical stabilizer.

A rotor-regulation system includes a rotor comprising a plurality of blades, a mechanically driven hydraulic pump, a rotor drive shaft operable to drive the rotor and the mechanically driven hydraulic pump, and a throttling valve coupled to the mechanically driven hydraulic pump and operable to modulate rotation of the rotor.

A rotor-regulation system includes a rotor comprising a plurality of blades, a mechanically driven hydraulic pump, a rotor drive shaft operable to drive the rotor and the mechanically driven hydraulic pump, and a throttling valve coupled to the mechanically driven hydraulic pump and operable to modulate rotation of the rotor.

Embodiments are directed to a rotor system for an aircraft comprising a gearbox configured to receive torque from a drive train, a mast having a first end and a second end, wherein the first end is attached to the gearbox and the mast configured to rotate in response to the torque from the drive train, a rotor hub attached to the second end of the mast, a first light transceiver mounted adjacent to the first end of the mast, wherein the first light transceiver is does not rotate relative to the mast, and a second light transceiver mounted adjacent to the second end of the mast, wherein the second light transceiver rotates with the mast.

Aircraft capable of vertical takeoff and landing, hovering, and efficient forward flight are described. An aircraft includes two side mounted tiltable proprotors and a central rotor disposed above the proprotors. The proprotors are tiltable between at least a horizontal position for forward flight and a vertical position for vertical or hovering flight. The central rotor may be powered for vertical and transitional flight modes and may turn by free autorotation during forward flight. The proprotors may be differentially tilted during vertical or hovering flight to counter torque effects of the central rotor. The central rotor may be foldable and/or easily detachable from the aircraft to facilitate storage and transportation. Left and right proprotors may provide both forward thrust and attitude control. Control inputs to left and right proprotors may be connected directly to an autopilot creating closed loop actuation using motor RPM feedback.

Aircraft capable of vertical takeoff and landing, hovering, and efficient forward flight are described. An aircraft includes two side mounted tiltable proprotors and a central rotor disposed above the proprotors. The proprotors are tiltable between at least a horizontal position for forward flight and a vertical position for vertical or hovering flight. The central rotor may be powered for vertical and transitional flight modes and may turn by free autorotation during forward flight. The proprotors may be differentially tilted during vertical or hovering flight to counter torque effects of the central rotor. The central rotor may be foldable and/or easily detachable from the aircraft to facilitate storage and transportation. Left and right proprotors may provide both forward thrust and attitude control. Control inputs to left and right proprotors may be connected directly to an autopilot creating closed loop actuation using motor RPM feedback.