A rotor blade for a rotary wing aircraft and a tip for the rotor blade. The rotor blade includes a blade root, a blade tip and a blade body that extends from the blade root to the blade tip. The blade tip includes: a continuously swept leading edge, a compound trailing edge, and a continuous anhedral.

Rotor assemblies for aircraft are described where one or more blades of the rotor assembly includes a blade alignment device that passively orients a blade in response to an airflow around the blade alignment device when the rotor assembly is free-wheeling. One embodiment comprises a method of operating a rotor assembly for aircraft. The method comprises operating the rotor assembly in a free-wheeling state, where the rotor assembly includes a rotary hub that rotates about an axis and a plurality of blades extending radially from the rotary hub. At least one of the plurality of blades includes a blade alignment device. The method further comprises aligning the at least one of the plurality of blades in response to airflow around the blade alignment device when the rotor assembly is in the free-wheeling state.

A wingtip of a lifting surface of an aeronautical vehicle, the lifting surface having a span, a leading edge, a trailing edge, an upper surface and a lower surface, the wingtip being in a range of five percent to fifteen percent of an end portion of the span of the lifting surface, the wingtip including: an elliptical shape between the leading and trailing edges, the elliptical shape tapering in a direction towards an outer edge of the wing tip, wherein the tapering occurs in a plurality of geometric parameters of the lifting surface including spanwise chord distribution between the leading and trailing edges, spanwise mean camber distribution between the leading including and trailing edges, spanwise maximum thickness between the upper and lower surfaces, and spanwise twist of a mean average of the spanwise chord distribution of the wingtip.

An aerodynamic blade is provided and includes a blade body and a light module. The blade body includes an inboard end and a tip outboard of the inboard end. The blade body is connectable with a hub at the inboard end such that rotations of the hub drive rotations of the tip about a rotational axis. The light module is disposed in the tip and configured to activate in response to the rotations of the tip about the rotational axis to emit light visible at an exterior of the blade body.

An aerodynamic blade is provided and includes a blade body and a light module. The blade body includes an inboard end and a tip outboard of the inboard end. The blade body is connectable with a hub at the inboard end such that rotations of the hub drive rotations of the tip about a rotational axis. The light module is disposed in the tip and configured to activate in response to the rotations of the tip about the rotational axis to emit light visible at an exterior of the blade body.

A biplaner rotor blade has an upper airfoil section connected to a lower airfoil section such that the upper airfoil and lower airfoil are rotated in separate planesan upper plane and a lower plane. The upper airfoil has a root end attached to a hub at an upper location of the hub and the lower airfoil has a root end attached to the hub at a lower location of the hub. The upper airfoil converges with the lower airfoil to form a blade tip end at the outermost portion of the blade, thus generating lift along two geometric planes.

A rotor system for a rotorcraft has a hub rotatable about an axis and a plurality of blades coupled to the hub for rotation therewith about the axis. Each blade is capable of rotation about a pitch axis relative to the hub, and a ring couples adjacent blades to each other.

A replacement tip section for a rotor blade, from which a legacy tip section was removed, includes a blade tip portion configured to be attached to an intermediate section of the rotor blade after removal of the legacy section. The intermediate section has a connection feature at an end of the intermediate section to which the blade tip portion is attachable. The replacement tip section includes a transition region configured to be attached to a forward end of the connection feature. The transition region is configured to form a leading edge of the rotor blade and extends from the blade tip portion to form an opening into which the intermediate section is attached. The transition region includes a first end having a first airfoil that conforms to the intermediate section airfoil at the connection feature, and a second end having a second airfoil that conforms to the blade tip portion.

Vortex reduction apparatus for use with airfoils are disclosed. An example vortex reduction apparatus includes a housing to couple to a tip of an airfoil. The housing defines a volute fluid flow passageway between an inlet and an outlet. The volute fluid flow passageway is structured to induce a rotational fluid flow in a first rotational direction opposite a second rotational direction of a shed vortex induced at the tip of the airfoil during flight.

An aerial vehicle may be equipped with propellers having reconfigurable geometries. Such propellers may have blade tips or other features that may be adjusted or reconfigured while the aerial vehicle is operating, on any basis. Propellers having reconfigurable blade tips joined to blade roots may cause the blade tips to be aligned with the blade roots, or substantially perpendicular to the blade roots, e.g., in order to counter adverse effects of tip vortices, or at any intervening angle. The propellers may be reconfigured at predetermined times during operation of an aerial vehicle, or upon sensing one or more operational characteristics or environmental conditions, as may be desired or required.