A composite piece tool used to create a composite piece. The tool includes a substrate having a substrate surface, walls disposed on the substrate and extending from the substrate surface in a thickness direction of the composite piece to define opposite locations of longitudinal composite piece ends and composite piece sides, a tooling surface disposed to occupy an entirety of a space delimited by the walls and on which the composite piece formed and a servo controller coupled to the tooling surface and configured to move the tooling surface upwardly and downwardly relative to the substrate surface and walls to form the composite piece.

A rotor assembly for a rotary wing aircraft includes a rotor hub having a central axis. The rotor hub is rotatable about the central axis. A plurality of flexible structural members extend radially outwardly from the rotor hub. Each flexible structural member is substantially U-shaped having a first arm extending from the hub, a second arm extending from the hub, and an end portion connecting the first arm to the second arm at a radially outboard end of the flexible structural member. The first arm, the second arm and/or the end portion have a cross section with a height along the central axis greater than a thickness of the cross section to increase stiffness of the rotor assembly along the central axis. The rotor assembly further includes a plurality of rotor blades, each rotor blade being secured to each flexible structural member of the plurality of flexible structural members.

A blade attachment (1, 20) for a bearingless main rotor of a helicopter with an airfoil blade (2), a flexbeam (3, 21) including a flexbeam body (16, 17) and a flexbeam head (13) at an end of the flexbeam body (16, 17). A control cuff (4, 22) encloses and extends along at least a predominant portion of the flexbeam (3, 21). A separable junction arrangement between the flexbeam head (13), the control cuff (4, 22) and the root end of the airfoil blade (2) is mechanical with removable fasteners. The removable fasteners comprise a main bolt (7) and at least one supporting bolt (8).

A blade attachment (1, 20) for a bearingless main rotor of a helicopter with an airfoil blade (2), a flexbeam (3, 21) including a flexbeam body (16, 17) and a flexbeam head (13) at an end of the flexbeam body (16, 17). A control cuff (4, 22) encloses and extends along at least a predominant portion of the flexbeam (3, 21). A separable junction arrangement between the flexbeam head (13), the control cuff (4, 22) and the root end of the airfoil blade (2) is mechanical with removable fasteners. The removable fasteners comprise a main bolt (7) and at least one supporting bolt (8).

A spar for a rotor blade assembly is provided including a generally hollow tubular body. A spacer protrudes from at least one surface of the body along a length of the body. A hole extends through the body and the spacer. The hole is configured to align with a through hole in an adjacent flexbeam assembly. The spacer is configured to contact a surface of the adjacent flexbeam assembly to create a match fit between the body and the flexbeam assembly.

A spar for a rotor blade assembly is provided including a generally hollow tubular body. A spacer protrudes from at least one surface of the body along a length of the body. A hole extends through the body and the spacer. The hole is configured to align with a through hole in an adjacent flexbeam assembly. The spacer is configured to contact a surface of the adjacent flexbeam assembly to create a match fit between the body and the flexbeam assembly.

The ‘Air Wheel’ rotor is a rotor with blades of variable pitch and variable twist. The ‘Air Wheel’ rotor comprises one or more hubs connected to the closed axisymmetric wing via flexible blades. There is provided a wide range of combinations of the wing relative width and coning angle typical for a lifting rotor with a thin planar wing attached to the tips of long blades, for a shrouded fan in a wide annular wing, or an impeller in a rotating cylindrical wing is provided.

The ‘Air Wheel’ rotor combines and enhances the advantages of a rotor and a wing. The ‘Air Wheel’ rotor has high aerodynamic properties, and eliminates limitations of the rotor size and flight speed. The ‘Air Wheel’ rotor can be used for designing vertical take-off and landing aircraft.

The ‘Air Wheel’ rotor is a rotor with blades of variable pitch and variable twist. The ‘Air Wheel’ rotor comprises one or more hubs connected to the closed axisymmetric wing via flexible blades. There is provided a wide range of combinations of the wing relative width and coning angle typical for a lifting rotor with a thin planar wing attached to the tips of long blades, for a shrouded fan in a wide annular wing, or an impeller in a rotating cylindrical wing is provided.

The ‘Air Wheel’ rotor combines and enhances the advantages of a rotor and a wing. The ‘Air Wheel’ rotor has high aerodynamic properties, and eliminates limitations of the rotor size and flight speed. The ‘Air Wheel’ rotor can be used for designing vertical take-off and landing aircraft.

An aircraft rotor assembly has a central hub and a plurality of rotor blades coupled to the hub for rotation with the hub about an axis, each blade having a Lock number of approximately 5 or greater. A lead-lag pivot for each blade is formed by a flexure coupling the associated blade to the hub. Each pivot is a radial distance from the axis and allows for in-plane lead-lag motion of the associated blade relative to the hub, each pivot allowing for in-plane motion from a neutral position of at least 1 degree in each of the lead and lag directions. Elastic deformation of the flexure produces a biasing force for biasing the associated blade toward the neutral position, and the biasing force is selected to achieve a first in-plane frequency of greater than 1/rev for each blade.

A rotor assembly for a rotorcraft, comprising a rotor shaft, a torque transmission unit that is non-rotatably mounted to the rotor shaft, a rotor hub that is rotatably mounted to the rotor shaft via an associated angular displacement enabling component, and at least two rotor blades that are connected to the rotor hub, wherein the torque transmission unit is coupled to the at least two rotor blades on a rotor assembly outflow side via a pitch control unit, wherein the pitch control unit transmits to the at least two rotor blades torque that is applied from the rotor shaft to the torque transmission unit, and wherein the pitch control unit increases a respective pitch angle of the at least two rotor blades if the torque is increased.