A pitch angle blocking device for blocking the pitch angle of a multi-blade rotor that has neighboring first and second rotor blades in circumferential direction that extend from a rotor hub of a rotary-wing aircraft In non-operational mode of the rotary-wing aircraft. The present embodiments further relate to a multi-blade rotor of a rotary-wing aircraft that is adapted to receiving such a pitch angle blocking device, and to a rotary-wing aircraft with such a multi-blade rotor. The pitch angle blocking device comprises first and second attachment means that are configured to be non-rotatably and releasably attached to the first and second rotor blades spaced apart from the rotor hub, and a connecting device that non-rotatably connects the first attachment means with the second attachment means.

An aerial vehicle includes a wing body. The aerial vehicle includes a plurality of rotors coupled to the wing body. Each one of the rotors includes a plurality of rotor blades. The aerial vehicle includes a drive assembly configured to rotate the rotors. The aerial vehicle includes a controller configured to selectively control thrust produced by each one of the rotors. Selective control of the thrust produced by each one of the rotors induces a pitch motion of the aerial vehicle to transition the aerial vehicle between a horizontal flight state and a vertical flight state. In the horizontal flight state, the wing body is approximately horizontal and a collective thrust from the rotors is directed forward. In the vertical flight state, the wing body is approximately vertical and the collective thrust from the plurality rotors is directed upward.

A rotor craft changes a torsional angle of a blade by driving an actuator. The rotor craft includes a plurality of torsion applying mechanisms that each twist a proximal end portion of a corresponding blade relative to a distal end portion of the corresponding blade about a center axis A of the blade. Each blade includes a spar having a proximal end portion connected to a hub and a skin in which the spar is inserted, such that a distal end portion of the skin and a distal end portion of the spar are connected to each other, and such that other portions of the skin than the distal end portion are rotatable relative to the spar about a center axis of the spar. The hub includes a hub body mounted to a main rotor shaft, and a hub arm that connects the spar to the hub body.

A turbine engine module having longitudinal axis X including an unducted propeller for rotating about the longitudinal axis X; —at least one flow straightener wiht a plurality of stator vanes extends substantially along a radial axis Z, each stator vane having a root and a blade rising radially from the root; and—a pitch change system for changing the pitch of the stator vanes. At least two adjacent stator vanes are connected to each other by at least one retaining member coupled to the blades of the stator vanes by at least one pivot shaft and mounted radially from the root of the stator vanes. The pivot shaft extends along a pivot axis B coaxial with the pitch adjustment axis A to enable the stator vanes to pivot about the pivot axis B. An anti-vibration unit dampens vibration of the pivot shaft.

A turbine engine module having longitudinal axis X including an unducted propeller for rotating about the longitudinal axis X; —at least one flow straightener wiht a plurality of stator vanes extends substantially along a radial axis Z, each stator vane having a root and a blade rising radially from the root; and—a pitch change system for changing the pitch of the stator vanes. At least two adjacent stator vanes are connected to each other by at least one retaining member coupled to the blades of the stator vanes by at least one pivot shaft and mounted radially from the root of the stator vanes. The pivot shaft extends along a pivot axis B coaxial with the pitch adjustment axis A to enable the stator vanes to pivot about the pivot axis B. An anti-vibration unit dampens vibration of the pivot shaft.

In an embodiment, proprotor pitch ranges used during nominal cruise flight may be varied. By selecting ideal combinations of proprotor pitch angle and proprotor rpm, instead of the proprotor blade pitch bearing spending most of its time in a first range, multiple ranges may be alternated between. Additionally, in an aircraft with multiple proprotors, the portion of total thrust produced by each individual proprotor may be varied over time in order to allow for proprotor blade pitch angle to be varied without varying proprotor rpm. By properly cycling between different blade pitch ranges, bearing life can be significantly increased.

A propeller system includes a rotatable housing having at least one propeller blade mounted thereon and an electric pitch control motor within the rotatable housing. A pitch control member is coupled to the propeller blade and extends through a wall of the rotatable housing. The pitch control motor is configured to move the pitch control member and to thereby vary the pitch of the propeller blade.

A propeller system includes a rotatable housing having at least one propeller blade mounted thereon and an electric pitch control motor within the rotatable housing. A pitch control member is coupled to the propeller blade and extends through a wall of the rotatable housing. The pitch control motor is configured to move the pitch control member and to thereby vary the pitch of the propeller blade.

An aircraft rotor system including a hub having a hub axis about which the hub is configured to rotate; a plurality of rotor blades configured to extend from the hub and rotate about the hub axis, at least one of the rotor blades rotatable about a respective pitch change axis; wherein the hub is configured to be rotated about the hub axis only by the plurality of rotor blades. Another aspect includes a method of operating the rotor system.

A propeller provided with interchangeable blades, and to a method of mounting such interchangeable blades on the propeller. The propeller comprises a hub, fastening fittings, rotation guide devices for guiding the fastening fittings in rotation relative to the hub, locking parts, and blades. The fastening fittings are configured to be assembled into the hub from the inside of the hub, and the locking parts lock respective ones of the fastening fittings onto the hub. The blades are fastened to respective ones of the fastening fittings outside the hub and can thus easily be replaced with other blades without removing the propeller.