Abstract: An elastic flapping hinge for connecting a rotor blade to a rotor hub of a rotary wing aircraft, comprising an elastic flapping hinge member arrangement that includes a hub attachment area for attachment to the rotor hub, a connection area for attachment to the rotor blade, and an elastic flapping hinge area that is arranged between the hub attachment area and the connection area and adapted to allow flapping movements, the elastic flapping hinge member arrangement comprising at least two elastic flapping hinge members having a first bending stiffness for flapping movements and a second bending stiffness for lead-lag movements, the first bending stiffness being smaller than the second bending stiffness, wherein the at least two elastic flapping hinge members diverge from each other in the elastic flapping hinge area by a predetermined divergence angle.

Abstract: An elastic torsion element for connecting a rotor blade to a rotor hub of a rotor, the elastic torsion element comprising at least two elastically deformable plates, wherein each one of the at least two elastically deformable plates comprises fiber reinforced polymers, wherein respective fibers of the fiber reinforced polymers of each one of the at least two elastically deformable plates are at least arranged along one of a first and a second dominant fiber directions, wherein the first dominant fiber direction crosses the second dominant fiber direction in a predetermined fiber direction crossing region, and wherein the elastic torsion element comprises an integrated elastic lead-lag hinge that is formed at the predetermined fiber direction crossing region.

Abstract: A multi-blade rotor for a rotary wing aircraft, comprising a plurality of rotor that is connected to an associated rotor head via a plurality of flexbeam elements, wherein at least one flexbeam element of the plurality of flexbeam elements comprises an asymmetrical flexbeam root that is mounted to the associated rotor head.

Abstract: An elastic torsion element for connecting a rotor blade to a rotor hub of a rotor, the elastic torsion element comprising at least two elastically deformable plates, wherein each one of the at least two elastically deformable plates comprises fiber reinforced polymers, wherein respective fibers of the fiber reinforced polymers of each one of the at least two elastically deformable plates are at least arranged along one of a first and a second dominant fiber directions, wherein the first dominant fiber direction crosses the second dominant fiber direction in a predetermined fiber direction crossing region, and wherein the elastic torsion element comprises an integrated elastic lead-lag hinge that is formed at the predetermined fiber direction crossing region.

Abstract: An elastic flapping hinge for connecting a rotor blade to a rotor hub of a rotary wing aircraft, comprising an elastic flapping hinge member arrangement that includes a hub attachment area for attachment to the rotor hub, a connection area for attachment to the rotor blade, and an elastic flapping hinge area that is arranged between the hub attachment area and the connection area and adapted to allow flapping movements, the elastic flapping hinge member arrangement comprising at least two elastic flapping hinge members having a first bending stiffness for flapping movements and a second bending stiffness for lead-lag movements, the first bending stiffness being smaller than the second bending stiffness, wherein the at least two elastic flapping hinge members diverge from each other in the elastic flapping hinge area by a predetermined divergence angle.

Abstract: In a rotary wing aircraft a bar (1) of composite matrix material has a longitudinal axis (8) perpendicular to a cross section with upper and lower surfaces (2, 3). At least one torsion box (17) comprises an upper and a lower layers (10, 21, 11, 22) respectively offset of a longitudinal axis (8) and of the upper and the lower surfaces (2, 3), said upper and lower layers (10, 21, 11, 22) being laterally joint, while cross sections are filled with the first group of fibers extending essentially parallel to the longitudinal axis (8).

Abstract: A multi-blade rotor for a rotary wing aircraft, comprising a plurality of rotor that is connected to an associated rotor head via a plurality of flexbeam elements, wherein at least one flexbeam element of the plurality of flexbeam elements comprises an asymmetrical flexbeam root that is mounted to the associated rotor head.

Abstract: 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).

Abstract: An airfoil blade (2) of a bearingless rotor of a helicopter. Said airfoil blade (2) has a pitch axis from a tip end to a root end and said root end is provided with junction means for a separable junction arrangement of said airfoil blade (2) with a flexbeam head (13), and a control cuff (4, 22). Said junction arrangement is mechanical with removable fasteners respectively removable connecting said root end of said airfoil blade (2) to said control cuff (4, 22) and said flexbeam head (13). Said root end comprises at least two openings (7, 8) being asymmetric with regard to said pitch axis.

Abstract: A partly cruciform flexbeam (1) of a bearingless main rotor system of a helicopter with a hub drive and an airfoil blade. The partly cruciform flexbeam (1) comprises a flexbeam head (2) with a flat bearing laminate at one end, a root end (3) opposed to said flexbeam head (2) and a flexbeam body (6) between said flexbeam head (2) and said root end (3), said flexbeam body (6) being torsion soft with a substantially cruciform cross section. The invention is as well related to a method of manufacturing such a partly cruciform flexbeam (1).

Abstract: In a rotary wing aircraft a bar (1) of composite matrix material has a longitudinal axis (8) perpendicular to a cross section with upper and lower surfaces (2, 3). At least one torsion box (17) comprises an upper and a lower layers (10, 21, 11, 22) respectively offset of a longitudinal axis (8) and of the upper and the lower surfaces (2, 3), said upper and lower layers (10, 21, 11, 22) being laterally joint, while cross sections are filled with the first group of fibers extending essentially parallel to the longitudinal axis (8).

Abstract: An aerodynamic blade attachment (1) for a bearingless rotor, particularly a main rotor, of a helicopter, comprising: an airfoil blade (2) having a tip end and a root end and having a pitch axis from said tip end to said root end; a flexbeam (3); a control cuff (4, 22) enclosing and extending along said flexbeam (3) and a separable junction arrangement between said flexbeam (3), said control cuff (4) and said root end of said airfoil blade (2). Said junction arrangement is mechanical between said flexbeam (3), said control cuff (4) and said root end of said airfoil blade (2). Removable fasteners (5, 6) connect said root end of said airfoil blade (2) and said control cuff (4) with said flexbeam (3). Said junction arrangement comprises fairing means (10, 27, 28, 31, 32 and 39) encompass the removable fasteners (5, 6) and said flexbeam (3).

Abstract: A partly cruciform flexbeam (1) of a bearingless main rotor system of a helicopter with a hub drive and an airfoil blade. The partly cruciform flexbeam (1) comprises a flexbeam head (2) with a flat bearing laminate at one end, a root end (3) opposed to said flexbeam head (2) and a flexbeam body (6) between said flexbeam head (2) and said root end (3), said flexbeam body (6) being torsion soft with a substantially cruciform cross section. The invention is as well related to a method of manufacturing such a partly cruciform flexbeam (1).

Abstract: 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 said flexbeam body (16, 17). A control cuff (4, 22) encloses and extends along at least a predominant portion of said flexbeam (3, 21). A separable junction arrangement between said flexbeam head (13), said control cuff (4, 22) and said root end of said airfoil blade (2) is mechanical with removable fasteners. Said removable fasteners comprise a main bolt (7) and at least one supporting bolt (8).