A tunable mass damper assembly is attachable to a rotor blade. The tunable mass damper assembly comprises a base configured to be attached to the rotor blade and a pendulum mass structure movably attached to the base and configured to move relative to the base in accordance with a rotational speed of the rotor blade about a rotor axis. The pendulum mass structure is configured to reduce vibratory forces of the rotor blade induced by a rotation of the rotor blade about the rotor axis. An entirety of the pendulum mass structure being configured to be contained within and enclosed by the rotor blade.

A fail safety apparatus of the air mobility is provided. Locations of propeller modules are adjusted by rotation parts and length adjustment units to evenly distribute thrust of the re-located propeller modules so that the attitude of the air mobility is stabilized. In particular, when one propeller module among a plurality of propeller modules fails, the attitude of the air mobility is normalized by adjusting a location of the failed propeller module and locations of remaining normal propeller modules so that flight safety of the air mobility is secured.

A blade positioning system and method are provided to dynamically measure blade position during flight of a rotorcraft. In the context of a method, a blade of the rotorcraft is repeatedly illuminated by a light source during flight of the rotorcraft while the blade is rotating. The method also includes detecting radiation scattered from the blade in response to illumination of the blade. The method further includes determining at least one of a blade pitch angle, a blade flap angle, a blade leading position or a blade lagging position based upon the radiation that is scattered from the blade and detected. A rotorcraft is also provided that includes a chip-scale light detection and ranging (LIDAR) sensor configured to illuminate the plurality of blades while the blades are rotating in order to permit blade position to be measured or to illuminate terrain beneath the rotorcraft in order to provide an altitude measurement.

A rotor-hub flap-measurement system includes a rotor hub operable to flap relative to a rotational axis of a rotor mast. The rotor hub includes a fork driver fixedly coupled to the rotor mast and operable to rotate about the rotational axis, a drive plate operable to rotate about the rotational axis and to rotate out of a plane perpendicular to the rotational axis, out-of-plane rotation indicating flapping of the rotor hub, and a universal joint coupled to the drive plate and comprising a cross, the cross comprising four trunnions equally spaced azimuthally about the rotational axis. The rotor-hub flap-measurement system also includes a magneto-resistive sensor system coupled to the cross and operable to detect rotation of a first trunnion of the four trunnions.

A tracking wedge, a rotor and a method for modifying a movement of air over a tracking wedge. According to aspects of the disclosure, a tracking wedge used to correct the tracking of a helicopter rotor blade may include one or more acoustic management mechanisms. The acoustic management mechanisms may change the manner in which air moves over the surface of the tracking wedge. In some examples, changing the manner in which air moves over the surface of the tracking wedge may reduce noise generated by the use of the tracking wedge.

The rotor of a hybrid aerodyne for producing lift by rotating during a stage of vertical flight and then for being held stationary and stored longitudinally during a stage of cruising flight has at least one single-blade with a counterweight. The length of the active blade that generates lift of the rotor while rotating is significantly shorter than the length of the radius of the rotor. The portion that carries the active blade that makes the connection between the active blade and rotor mast is structurally rigid. The rigid portion that carries the active blade presents a cross-section optimized to provide zero or almost zero lift and very little aerodynamic drag while the rotor is rotating. The assembly is hinged about a transverse axis perpendicular to the vertical axis of the rotor and substantially on the vertical axis of the rotor mast.

A device to verify main rotor swashplate positioning includes an inner surface of a first section and a gradient surface of a second section. The gradient surface of the second section may have a plurality of graduation indications. In one implementation, the inner surface of the first section at least partially defines a travel arc that is parallel to and concentric with the inner surface. In such an implementation, the device may be configured to move along the travel arc as it rotates about a collective sleeve to contact a swashplate lug.

A rotor system is provided including a rotor hub configured to rotate about an axis and a plurality of rotor blade assemblies mounted to the rotor hub and configured to rotate within a plane about the axis. A vibration reducing system is operably coupled to the rotor hub. The vibration reducing system is arranged at a position offset from a center of rotation of the rotor hub.

A rotor-hub flap-measurement system includes a rotor hub operable to flap relative to a main-rotor axis, a flap-linkage arm, a first end of the flap-linkage arm rotatably coupled to the rotor hub, the flap-linkage arm responsive to flapping of the rotor hub, and a magneto-resistive sensor system rotatably coupled to a second end of the flap-linkage arm and responsive to movement of the flap-linkage arm.

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.