A propeller system for a tail section of an aircraft includes a propeller hub located at the tail section of the aircraft, a plurality of propeller blades mounted to and extending outwardly from the propeller hub, a propeller shaft coupled to the propeller hub and operable to rotate the propeller hub about an axis of rotation, and a propeller gearbox connected to the propeller shaft. The propeller gearbox is fluidly cooled by an airflow within the tail section. A spinner assembly surrounds the propeller hub. The spinner assembly includes at least one outlet opening formed therein downstream from the propeller hub relative to the airflow. The spinner assembly is rotatable to draw the airflow into at least one cooling flow inlet formed in the tail section and across the propeller gearbox to cool the propeller gearbox and out the at least one outlet opening.

A rotor for a hover-capable aircraft is described that comprises: a hub rotatable about a first axis and at least two blades hinged to the hub; each blade comprises a main portion hinged to the hub and a tip portion, which is arranged radially outermost with respect to first axis with respect to the corresponding main portion; the tip portion of each blade is movable with respect to the corresponding main portion of that blade; the tip portion of each blade is selectively movable with respect to the corresponding main portion of that blade between a first position, in which it defines a dihedral or anhedral angle with respect to the corresponding main portion; and a second position, in which it defines a positive or negative sweep angle with respect to the corresponding main portion.

A rotor for a hover-capable aircraft is described that comprises: a hub rotating about an axis and, in turn, comprising a plurality of blades, a mast connectable to a power unit of the aircraft and operatively connected to the hub to drive the hub in rotation about said axis, and an attenuating device to attenuate the transmission of vibrations from the mast to the aircraft parallel to said; the attenuating device, in turn, comprising a casing, a first mass free to oscillate parallel to said axis with respect to the casing and elastically connected to the casing, a second mass free to oscillate parallel to said axis, connection means adapted to make the first and second masses integrally movable along said axis when the angular speed of the mast assumes a first value, and actuator means activatable to decouple the first and second masses when the angular speed of the mast assumes a second value, different from the first value.

A rotor for a hover-capable aircraft is described that comprises: a hub rotating about an axis and, in turn, comprising a plurality of blades, a mast connectable to a power unit of the aircraft and operatively connected to the hub to drive the hub in rotation about said axis, and an attenuating device to attenuate the transmission of vibrations from the mast to the aircraft parallel to said; the attenuating device, in turn, comprising a casing, a first mass free to oscillate parallel to said axis with respect to the casing and elastically connected to the casing, a second mass free to oscillate parallel to said axis, connection means adapted to make the first and second masses integrally movable along said axis when the angular speed of the mast assumes a first value, and actuator means activatable to decouple the first and second masses when the angular speed of the mast assumes a second value, different from the first value.

A tiltrotor aircraft is designed to accommodate rotors of different diameters, as well as corresponding wings and fuselages with different span and length, while maintaining very high parts commonality, especially with respect to drive train and power source. This enables design and operation of a fleet of such aircraft with significantly different rotor diameters, which are nevertheless optimized for different missions. In preferred embodiments the rotors are configured to have high stiffness and low weight to reduce aero-structural dynamic issues across the fleet. Also in preferred embodiments drive systems are designed for a full range of speed, torque, and power associated with all intended rotors. Turboshaft engine speeds are restricted to a narrow RPM range, so that a single gearset can be replaced to achieve the desired rotor RPM. Also in preferred embodiments, aircraft in a fleet can differ in folded length, empty weight, payload length by up 50%.

A UAV preferably has 6 rotors mounted on an H-Frame setup with two parallel longitudinally extending support beams with a cross beam. The rotors are mounted along the longitudinal extending support beams, with one rotor mounted at each end and one motor mounted at the cross beam. Such an arrangement is more efficient than a helicopter of similar disk size and will be more efficient than a traditional hex rotor setup when lifting heavy payloads at a construction site.

A flight vehicle capable of improving the accuracy of the arrival position of baggage. The flight vehicle according to the present disclosure includes a mounting unit that holds a mounted object, holds the mounting unit via a string member, and has a moving means including a rotor blade provided between the upper end and the lower end of the mounting unit, when the mounting unit is viewed from the side.

A bond fixture includes a frame defining a chamber for receiving a component. At least one bladder assembly is connected to the frame. The at least one bladder assembly includes a pad for contacting the component. A position of the pad relative to the component is controlled by a pressure of the bladder assembly. A caul assembly is adapted to thermally couple to the component to heat a localized portion of the component.

A bond fixture includes a frame defining a chamber for receiving a component. At least one bladder assembly is connected to the frame. The at least one bladder assembly includes a pad for contacting the component. A position of the pad relative to the component is controlled by a pressure of the bladder assembly. A caul assembly is adapted to thermally couple to the component to heat a localized portion of the component.

Rotor assemblies for aircraft are described where one or more blades of the rotor assembly includes a blade alignment device that passively orients a blade in response to an airflow around the blade alignment device when the rotor assembly is free-wheeling. One embodiment comprises a method of operating a rotor assembly for aircraft. The method comprises operating the rotor assembly in a free-wheeling state, where the rotor assembly includes a rotary hub that rotates about an axis and a plurality of blades extending radially from the rotary hub. At least one of the plurality of blades includes a blade alignment device. The method further comprises aligning the at least one of the plurality of blades in response to airflow around the blade alignment device when the rotor assembly is in the free-wheeling state.