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 main rotor blade 1, which is the main rotor blade 1 for a high-velocity helicopter, includes: a blade root part 10 having a length of 30% or more of a rotor radius R; and a blade main body 20 continuous with the blade root part 10. Preferably, a cross-sectional shape of the blade root part 10 satisfies (x/a).sup.m+(y/b).sup.m=1 and a>b, where m: arbitrary number, x: chord length direction, and y: blade thickness direction.

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 system for regenerating fastener holes in a replacement tip section of a rotor blade includes a first fixture, a second fixture, and a third fixture positionable adjacent a tip section of the rotor blade. The first fixture is used to verify a position of an opening formed in the spar. The second fixture includes a removable bushing having a drillable opening. The drillable opening is aligned with the at least one opening formed in the spar and defines at least one hole to be formed in the replacement tip section. The third fixture includes a countersink opening. The countersink opening is aligned with the at least one hole to be formed in the replacement tip section and the at least one opening formed in the spar to define a countersink feature to be formed in the at least one hole.

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.

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.

The present disclosure relates to a blade and a rotor of a rotor craft, and a rotor craft. The blade includes a blade root, a blade tip, and an upper aerofoil and a lower aerofoil disposed vertically opposite to each other. One sides of the upper aerofoil and the lower aerofoil are connected to form a front edge, and other sides of the upper aerofoil and the lower aerofoil are connected to form a tail edge. The upper aerofoil is defined by an upper aerofoil characteristic line formed by (kx, ky, kz) defined by a plurality of coordinate pairs. The lower aerofoil is defined by a lower aerofoil characteristic line formed by (kx, ky, kz) defined by a plurality of coordinate pairs.

A proprotor blade for a ducted aircraft including a duct includes a main body having a distal end and a sacrificial blade tip coupled to the distal end of the main body. The sacrificial blade tip includes a deformable core material and a shell layer at least partially covering the deformable core material. The sacrificial blade tip deforms upon contact with the duct, thereby reducing damage to the ducted aircraft.

A vertical take-off and landing aircraft includes a ducted rotary wing. The ducted rotary wing includes a duct and a rotary wing. The duct runs through a body from an upper surface to a lower surface thereof. The rotary wing is provided inside the duct and includes a hub and a blade configured to rotate about the hub. The blade includes a tip inlet, a trailing-edge outlet, and a trailing-edge flow path. The tip inlet is provided on a tip surface of the blade. The trailing-edge outlet is provided at a trailing edge that is an edge on a rear side in a rotation direction of the blade. The trailing-edge flow path allows the tip inlet and the trailing-edge outlet to be in communication with each other.