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.

A wing tip designed for attachment to a winglet of an aircraft, the winglet coupled to a wing of the aircraft and having a leading edge and a trailing edge continuously transitioning from a leading edge and trailing edge of the wing. The wing tip may include a curved leading edge from the winglet leading edge to a leading end point, a curved trailing edge from a winglet trailing edge to a trailing end point, and an end segment connecting the leading end point and the trailing end point. The end segment may be swept back from the trailing end point to the leading end point at an end segment angle.

A rotor blade is provided. The rotor blade includes a blade portion, a tip cap formed to define a dimple, a fastener and a doubler. The fastener includes a flat-headed shaft and is disposable such that the flat-headed shaft extends through the blade portion and the tip cap at the dimple. The fastener is configured to urge the blade portion toward the tip cap. The doubler includes a dimpled portion disposable between the tip cap and a portion of the flat-headed shaft at the dimple and an exterior portion. The exterior portion is disposable flush with respective exterior surfaces of the blade portion and the flat-headed shaft.

A rotor blade assembly includes a blade body having a leading edge and a trailing edge. A damper element is disposed within the blade body and along a forcing axis extending between the leading and trailing edges of the blade body to apply damping force in-plane with the blade body to damp load and oppose edgewise motion of the blade body associated with the load.

A rotor blade configured to couple to a rotor assembly having an axis of rotation includes a blade radius R between the axis of rotation and an outboard end of the rotor blade when coupled to the rotor assembly. When an inboard end of the rotor blade is coupled to the rotor assembly at about x/R=0.10, between about 18 percent and about 22 percent of the total mass of the rotor blade is located between about x/R=0.88 and about x/R=0.93, x corresponding to a radial location of the rotor blade measured from the axis of rotation.

Wingtip shields are described. In one embodiment, a wingtip shield includes an inner surface facing a high-pressure side of an airfoil. The airfoil is attached to the main body. The wingtip shield also includes an outer surface configured opposite from the inner surface. The wingtip shield is attachable to the airfoil along a peripheral edge of the airfoil from a first point of a leading edge of the airfoil to a second point of a trailing edge of the airfoil. A first span distance from the first point at the leading edge to the main body is less than a second span distance of the second point at the trailing edge to the main body.

The present disclosure presents systems, apparatuses, and methods of active flow controls for dissipating tip vortices. In this regard, a method comprises positioning one or more fan-shaped plasma actuators on an end surface of a tip of one or more airfoils of an aircraft, wherein the fan-shaped plasma actuators are surface compliant with the surface of the tip of the one or more airfoils; and activating the one or more fan-shaped plasma actuators during a flight of the aircraft, wherein at least one tip vortex generated by a flight of the aircraft is reduced by an introduction of one or more vortices generated by the one or more fan-shaped plasma actuators on the end surface of the tip of the one or more airfoils of the aircraft. Other systems, apparatuses, and methods are also presented.

A blade for use in a rotor of an aircraft is swept in a region extending to a blade tip from a first position located between the rotation center of the rotor and the blade tip in a radial direction of the VTOL rotor, the sweep amount increases from the first position toward the blade tip, and the rate of change of the sweep amount in a region extending to the blade tip from a second position located between the first position and the blade tip in the radial direction of the VTOL rotor, is greater than the rate of change of the sweep amount in a region extending from the first position to the second position.

The disclosed rotorcraft includes a rotor blade and a prime mover. The rotor blade extends in a radial direction. The prime mover is configured to rotate the rotor blade. The rotor blade includes a blade body and a blade end portion. The blade end portion is disposed on an outer side of the blade body in the radial direction. The blade end portion includes a leading edge (i.e., an edge facing the rotational direction) that tilts in a rotational direction to the outer side in the radial direction. The disclosed configuration reduces noise produced by the rotorcraft.

A method of designing a rotor blade for a rotary aircraft includes establishing a target thrust-weighted solidity of the rotor blade, calculating a reverse flow circle of the rotor blade at a target forward speed of the rotary aircraft, inboard of the reverse flow circle, decreasing chord of the rotor blade relative to a baseline rotor blade possessing the target thrust-weighted solidity, and outboard of the reverse flow circle, increasing the chord of the rotor blade relative to the baseline rotor blade. The rotor blade possesses the target thrust-weighted solidity of the baseline rotor blade and improved stall margin or speed margin at the target forward speed relative to the baseline rotor blade.