A hybrid electric aircraft equipped with gyroscopic stabilization control is provided. In one aspect, a hybrid electric aircraft includes a turbo-generator having a gas turbine engine and an electric generator operatively coupled thereto for generating electrical power. The turbo-generator defines a rotation axis. The aircraft also includes one or more electrically-driven propulsors for producing thrust for the aircraft. In addition, the aircraft includes a pivot mount operatively coupled with the turbo-generator. To provide gyroscopic stabilization control of the aircraft, the pivot mount is controlled to adjust the rotation axis of the turbo-generator relative to a prime stability axis of the aircraft. Additionally or alternatively, a rotational speed of the turbo-generator can be changed to provide gyroscopic stabilization control of the aircraft.

An abnormality warning system provides an abnormality warning for multiple motor systems that drive a motor used correspondingly to each of multiple rotors included in an electric aircraft. The abnormality warning system includes an abnormality determination unit and a warning level setting unit. The abnormality determination unit determines an abnormal one of the motor systems. The warning level setting unit sets a warning level to warn abnormality, based on at least position information of the rotor in the electric aircraft or the usage of the rotor corresponding to a motor system determined to be abnormal by the abnormality determination unit.

An aircraft includes a short-range radar that is configured to detect a trajectory, which is specified based on a position detection of the aircraft by a ground station.

A tiltrotor aircraft having a propulsion configuration that divorces the engine core power from the thrust fan, using a combined gearbox with a plurality of clutches to couple and decouple one or more rotor systems and one or more thrust fans. The aircraft can be operable for vertical takeoff and landing (VTOL) in a helicopter mode, forward flight in a proprotor mode, and high-speed forward flight in an airplane (jet) mode. The propulsion configuration provides shaft horsepower (SHP) to rotors for VTOL flight, while also providing SHP to the thrust fan for high speed flight. Allowing the rotor and the thrust fan to be clutched on and off, sequentially, enables transition from rotor-borne VTOL flight to wing-borne thrust fan flight, and back.

A vibration attenuator for a rotor of an aircraft has a housing adapted for rotation with the rotor about an axis. A first ring is rotatably carried within the housing on a first bearing, a first weight being coupled to the first ring for rotation therewith relative to the housing about the axis. A second ring is rotatably carried by the first ring on a second bearing, a second weight being coupled to the second ring for rotation therewith relative to the housing and to the first ring. A first motor is configured for rotating the first ring relative to the housing, and a second motor is configured for rotating the second ring relative to the housing and to the first ring. The first and second motors are operated to rotate the weights within the housing and position the weights relative to each other for attenuating vibrations.

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.

A ducted propulsion assembly for an aircraft includes a duct and a plurality of stators. The distal ends of the stators are coupled to the duct. The ducted propulsion assembly includes a line replaceable centerbody assembly isostatically coupled to the proximal ends of the stators. The line replaceable centerbody assembly includes one or more electric motors driving an output driveshaft. The ducted propulsion assembly also includes a proprotor assembly interchangeably coupled to and rotatable with the output driveshaft of the line replaceable centerbody assembly. The proprotor assembly is rotatable in a rotational plane to generate thrust.

Winged tilt-rotor vertical take-off and landing (VTOL) aircraft and related methods are disclosed. Aircraft comprise an airframe comprising one or more wings; one or more tilt-adjustable rotors positioned forward of the one or more wings; and one or more fixed-tilt rotors positioned behind at least one of the one or more wings. Methods comprise tilting only one or more forward rotors positioned in front of one or more wings of the aircraft, and not tilting one or more rearward rotors positioned behind at least one of the one or more wings.

A vertical take-off and landing multirotor aircraft with an airframe and at least eight thrust producing units, each one of the at least eight thrust producing units being provided for producing thrust in an associated predetermined thrust direction, wherein at least four thrust producing units of the at least eight trust producing units form a first thrust producing units sub-assembly, and at least four other thrust producing units of the at least eight thrust producing units form a second thrust producing units sub-assembly, the first thrust producing units sub-assembly being operable independent of the second thrust producing units sub-assembly.

A system for retaining a folded proprotor blade in flight. The system includes a rotary actuator mechanism operable to generate torque via a shaft that rotates about an axis generally parallel to a chordwise direction of the folded proprotor blade, a pair of clamping arms movable in a direction generally parallel to a beamwise direction of the folded proprotor blade, a pair of linkage arms interoperably responsive to the rotary actuator mechanism and coupled between the rotary actuator mechanism and the pair of clamping arms, and a first guide rod extending between the pair of clamping arms in the direction generally parallel to the beamwise direction.