A rotor-hub-flap anisotropic-sensor system includes a rotor hub, a plurality of anisotropic-sensor arrangements interoperably coupled to the rotor hub and operable to measure flapping of the rotor hub, a plurality of rotor blades connected to the rotor hub, and at least one flight control computer interoperably coupled to the plurality of anisotropic-sensor arrangements.

A rotor arm assembly for use in a rotor craft rotor hub system includes a pitch shaft and a plurality of discrete bearings coupled to the pitch shaft. The plurality of bearings are elastomeric bearings configured to facilitate movement of the rotor arm assembly about a plurality of degrees of freedom. A respective one of the plurality of bearings is configured to accommodate a single degree of freedom.

A rotor arm assembly for use in a rotor craft rotor hub system includes a pitch shaft and a plurality of discrete bearings coupled to the pitch shaft. The plurality of bearings are elastomeric bearings configured to facilitate movement of the rotor arm assembly about a plurality of degrees of freedom. A respective one of the plurality of bearings is configured to accommodate a single degree of freedom.

A helicopter includes a gimbal assembly, a first rotor assembly, a second rotor assembly, a fuselage, and a controller. The first rotor assembly, the second rotor assembly, and the fuselage are mechanically coupled to the gimbal assembly. The first rotor assembly includes a first rotor and the second rotor assembly includes a second rotor, the first rotor including a plurality of first fixed-pitch blades and the second rotor including a plurality of second fixed-pitch blades. Each of the plurality of first and the second fixed-pitch blades are coupled to a hub of its respective rotor via a hinge mechanism that is configured to allow each of the fixed-pitch blades to pivot from a first position to a second position, the first position being substantially parallel to the fuselage and the second position being substantially perpendicular to the fuselage.

A helicopter includes a gimbal assembly, a first rotor assembly, a second rotor assembly, a fuselage, and a controller. The first rotor assembly, the second rotor assembly, and the fuselage are mechanically coupled to the gimbal assembly. The first rotor assembly includes a first rotor and the second rotor assembly includes a second rotor, the first rotor including a plurality of first fixed-pitch blades and the second rotor including a plurality of second fixed-pitch blades. Each of the plurality of first and the second fixed-pitch blades are coupled to a hub of its respective rotor via a hinge mechanism that is configured to allow each of the fixed-pitch blades to pivot from a first position to a second position, the first position being substantially parallel to the fuselage and the second position being substantially perpendicular to the fuselage.

A damper for a rotor hub for a rotorcraft can include a housing, a piston resiliently coupled to the housing with a first elastomeric member and a second elastomeric member, a plurality of conical members, a fluid, and an orifice.

A damper for a rotor hub for a rotorcraft can include a housing, a piston resiliently coupled to the housing with a first elastomeric member and a second elastomeric member, a plurality of conical members, a fluid, and an orifice.

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.

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.

An exemplary continuous variable pitch rotor system includes a blade extending radially from a hub along a longitudinal axis, the blade rotationally coupled to the hub to permit limited rotation of the blade about the longitudinal axis in response to a change in a rotational speed of the hub. In some embodiments, the blade is held in a radially fixed position relative to the hub. In some embodiments, the blade is permitted to translate radially.