A propeller blade arrangement comprising a propeller blade attached to and rotatable with a hub, via a retention bearing, the blade being rotatable about a center line of the blade, the retention bearing configured to tilt the blade such that its center line is tilted with respect to the hub.

A rotor system includes a rotor duct; at least one rotor blade that includes an outboard end; a tip extension mechanism affixed at the outboard end of the at least one rotor blade, the tip extension mechanism including at least one shim, the at least one rotor blade with the tip extension mechanism affixed thereto including an extended rotor blade; and a blade tip affixed to an outboard end of the extended rotor blade, wherein the blade tip is affixed to the extended rotor blade via at least one removable fastener.

Anti-icing stacks for protecting an aerodynamic surface are described. In some embodiments, an anti-icing stack includes an anti-icing layer, an elastomeric erosion protection layer, and an additional layer. The erosion protection layer is disposed between the anti-icing layer and the additional layer. The additional layer has a thickness greater than the thickness of the erosion protection layer and a tensile modulus of no more than the tensile modulus of the erosion protection layer. The additional layer may be a foam adhesive layer.

An example unmanned aerial vehicle includes a housing; a wireless communication module; a plurality of propulsion systems; and a navigation circuit. At least one of the plurality of propulsion systems includes a motor; and a propeller assembly rotatably connected to the motor. The propeller assembly comprises: a hub structure including a surface facing away from the motor; a first connecting member including a first post and a second post extending in parallel to and spaced apart from the first post, and the first post and the second post are fixed to the surface and are able to move elastically in a second direction perpendicular to the first direction; a first blade detachably coupled to the first connecting member and comprising an opening to which the first post and the second post are coupled; and a cap detachably coupled to the top of the first connecting member.

An example unmanned aerial vehicle includes a housing; a wireless communication module; a plurality of propulsion systems; and a navigation circuit. At least one of the plurality of propulsion systems includes a motor; and a propeller assembly rotatably connected to the motor. The propeller assembly comprises: a hub structure including a surface facing away from the motor; a first connecting member including a first post and a second post extending in parallel to and spaced apart from the first post, and the first post and the second post are fixed to the surface and are able to move elastically in a second direction perpendicular to the first direction; a first blade detachably coupled to the first connecting member and comprising an opening to which the first post and the second post are coupled; and a cap detachably coupled to the top of the first connecting member.

An exemplary blade lock for a tiltrotor aircraft to enable and disable a folding degree of freedom and a pitching degree of freedom of a rotor blade assembly includes a link pivotally connected to a lever and a bellcrank, where the link is in a center position when the lever is in a locked position disabling the folding degree of freedom and the lever is secured in the locked position when the link is positioned in an over-center position.

An exemplary blade lock for a tiltrotor aircraft to enable and disable a folding degree of freedom and a pitching degree of freedom of a rotor blade assembly includes a link pivotally connected to a lever and a bellcrank, where the link is in a center position when the lever is in a locked position disabling the folding degree of freedom and the lever is secured in the locked position when the link is positioned in an over-center position.

An improved efficiency propeller for aircraft includes a blade structure mounted onto a propeller hub, a servo unit, and a cantilevered base. A distinctive feature of the invention is that the blade structure includes a main mast, which is mounted onto a propeller hub and forms the spine of the leading edge of the blade structure, and at least one secondary mast aligned with the main mast, and turning spacers with struts fitted with a strut are mounted onto the main mast, and the struts are covered by lateral pieces of a skin module, and the overlapping and flexible lateral piece of the skin module form a skin.

The invention relates to a test stand comprising a support (19, 25) which is moveably connected to a wall (18, 18′, 18″), a base, a frame (26) of the test stand or another part of the test stand and can be moved on a predetermined path; an actuator (22) which is connected to the support and by means of which the support (19, 25) that can be moved on the predetermined path, two clamping devices (13) respectively comprising a ball joint, wherein one of the two clamping devices (13) is seemed to the support (19, 25) and the other of the two clamping devices (13) is arranged in an axis (10) with the first of the two clamping devices (13), such that a test body (1) is clamped between the two clamping devices (13) on outer surfaces of the test body and can be maintained by the clamping devices (13), and a test force exerted by a test body by moving the support (19, 25) through the first of the two clamping devices (13) acts essentially along the axis (10). The test body is fixed by means of an elastic element (23) in order to limit a rotation of the test body about the axis (10).

The invention relates to a test stand comprising a support (19, 25) which is moveably connected to a wall (18, 18′, 18″), a base, a frame (26) of the test stand or another part of the test stand and can be moved on a predetermined path; an actuator (22) which is connected to the support and by means of which the support (19, 25) that can be moved on the predetermined path, two clamping devices (13) respectively comprising a ball joint, wherein one of the two clamping devices (13) is seemed to the support (19, 25) and the other of the two clamping devices (13) is arranged in an axis (10) with the first of the two clamping devices (13), such that a test body (1) is clamped between the two clamping devices (13) on outer surfaces of the test body and can be maintained by the clamping devices (13), and a test force exerted by a test body by moving the support (19, 25) through the first of the two clamping devices (13) acts essentially along the axis (10). The test body is fixed by means of an elastic element (23) in order to limit a rotation of the test body about the axis (10).