A cover panel for an aircraft including: a first region, a second region for forming an overlap with a second panel, and a ramp, wherein at least a portion of the ramp is between the first and second regions, wherein the ramp includes a tapered region such that a width of the ramp tapers towards a free-edge of the first region, and wherein the free-edge is configured to form a butt-joint with the second panel.

An unmanned aerial vehicle includes a fuselage body and a lift mechanism. The lift mechanism includes a rotor blade assembly and a rotary driving member and defines an axis of rotation. The lift being mechanism is coupled to the fuselage body. The rotary driving member is configured to controllably rotate the rotor blade assembly about the axis of rotation. The rotor blade assembly includes at least one rotor blade. The at least one rotor blade including a vortex generator defined along an upper surface of the rotor blade.

An unmanned aerial vehicle includes a fuselage body and a lift mechanism. The lift mechanism includes a rotor blade assembly and a rotary driving member and defines an axis of rotation. The lift being mechanism is coupled to the fuselage body. The rotary driving member is configured to controllably rotate the rotor blade assembly about the axis of rotation. The rotor blade assembly includes at least one rotor blade. The at least one rotor blade including a vortex generator defined along an upper surface of the rotor blade.

An aircraft can include a first wing and a second wing. The first wing can extend laterally from an aircraft body to a first tip, and the second wing can extend laterally from the aircraft body to a second tip. The aircraft can include a first end effector and a second end effector, each including a fore winglet and an aft winglet. The fore and aft winglets of the first end effector can be pivotably connected to the first tip. The fore and aft winglets of the second end effector can be pivotably connected to the second tip. The fore and aft winglets of the first and second end effectors can be independently operable. The first and second end effectors can be independently operable. A processor can be operatively connected to control movement of the fore and aft winglets of the first and second end effectors.

A Short Takeoff and Landing (STOL) aircraft has a fuselage with an axis and an engine providing thrust, a first aileron at an end of a first wing, a second aileron at an end of a second wing, a first slot having a length through the first wing proximate the first aileron, orthogonal to the axis; a second slot having a length through the second wing proximate the second aileron, orthogonal to the axis; a first electric motor in the first wing driving a first two-blade propeller in the first slot, a second electric motor in the second wing driving a second two-blade propeller in the second slot, and a control mechanism enabling a user to drive the first and second electric motors in a same rotary direction, to reverse the rotary direction, and to drive the first and second motors at a same rpm.

An adjustable lift modification wingtip may be attached to a baseline wing of an aircraft. The adjustable lift modification wingtip may comprise a horizontal portion including a control surface and a vertical portion coupled to the horizontal portion. The vertical portion may move about an axis that may be substantially perpendicular to the horizontal portion. The control surface and the vertical portion may be adjusted in conjunction to increase wing efficiency at a flight condition.

A strake may extend along a portion of an approaching side of a tail boom of a helicopter. A number of vortex generators (VGs) may extend along a portion of a retreating side of the tail boom. For tail booms with circular cross sections, the strake and the VGs are positioned between approximately 5 and 15 degrees below a horizontal plane of the tail boom when viewed end on, on respective sides of the tail boom. For tail booms with non-circular cross sections, the strake and the VGs is positioned between approximately 5 and 15 degrees above a location where a change in curvature is greatest (e.g., where flow separation would otherwise occur) on a bottom half of the tail boom when viewed end on, on respective sides of the tail boom. A fairing may be located on the retreating side on the upper half of the tail boom, to create an asymmetric profile.

A strake may extend along a portion of an approaching side of a tail boom of a helicopter. A number of vortex generators (VGs) may extend along a portion of a retreating side of the tail boom. For tail booms with circular cross sections, the strake and the VGs are positioned between approximately 5 and 15 degrees below a horizontal plane of the tail boom when viewed end on, on respective sides of the tail boom. For tail booms with non-circular cross sections, the strake and the VGs is positioned between approximately 5 and 15 degrees above a location where a change in curvature is greatest (e.g., where flow separation would otherwise occur) on a bottom half of the tail boom when viewed end on, on respective sides of the tail boom. A fairing may be located on the retreating side on the upper half of the tail boom, to create an asymmetric profile.

An aircraft wing (2) including a main wing (3) and a wing tip device (4) at the tip of the main wing (3), wherein the wing tip device (4) has a variation of leading edge droop with respect to unrolled span-wise position such that flow separation on the wing tip device (4) first occurs in an outboard region (O) of the wing tip device (4). The leading edge droop of the wing tip device (4) may be a maximum in an outboard region (O) of the wing tip device.

A wing of an aircraft that includes a wing leading edge, a wing trailing edge, and a wing surface defined by a wing upper surface and a wing lower surface is described herein. The wing extends from the wing root to the wingtip, and the wingtip has a wingtip chord. A winglet extends from the wingtip and has a winglet leading edge, a winglet trailing edge, a winglet inboard surface, a winglet outboard surface, a winglet root having a winglet root chord, and a winglet tip. A flow fence is disposed on the wing surface inboard from the winglet and overlapping with the winglet. The flow fence is adapted to delay and/or prevent airflow separation on the winglet inboard surface at high angle of sideslip, increasing lateral stability and linearizing aircraft behavior at high angle of sideslip.