A skin for an aircraft is configured to be disposed on a first rigid member and on a second rigid member. The second rigid member is movable with respect to the first rigid member and a distance is defined between the first rigid member and the second rigid member. A morphing member of the skin extends between the first rigid member and the second rigid member. The morphing member comprises first segments forming a first portion attached to the first rigid member and second segments forming a second portion attached to the second rigid member. The first and second portions are separated along a substantially linear seam in the absence of change in the distance and an orientation between the first rigid member and the second rigid member.

A multirotor aircraft that includes a chassis, at least three engines that are equipped with propellers, and a free wing that is axially connected to the chassis. The attack angle of the free wing is changed relatively to the chassis due to flow of air. When the aircraft is hovering then the free wing is free to rotate, when wind flows over the wing during hovering then the tilt angle of the wing is changed by forces of the wind to a position in which a drag force on the wing is reduced, and by that enables a precise hovering relative to a ground point and precise control over the aircraft. The free wing provides lift force in horizontal flight and in situations of front horizontal wind during hovering and by that reducing the amount of energy required to operate the aircraft.

An aircraft includes a fuselage and first and second pairs of aerofoils, the aerofoils of each pair extend from opposing sides of the fuselage. Each aerofoil includes a first lift body and a second lift body which is arranged behind the first lift body in a direction of flow of the aerofoil. The second lift body is pivotable relative to the first lift body between a cruising flight position in which both lift bodies together define an elongate and substantially continuous cross section of the aerofoil in the direction of flow, and a take-off/landing position in which the second lift body is angled downwards relative to the first lift body in order to increase a lift of the aerofoil. At least one engine is arranged on the second lift body of at least one of the first and second pairs of aerofoils.

A multi-boom aircraft with an adjustable wing geometric twist includes at least one wing, and at least three booms arranged transversely to at least one of the wings. Each of the booms includes at least one actuator, and the at least one wing is mounted on the booms so as at least a portion of the corresponding wing can be pivoted by means of the actuators about an axis extending substantially along the corresponding wing.

A method for operating a propulsion system of an aircraft includes moving a plurality of forward and aft propulsors to a vertical thrust position. While in the vertical thrust positions, the method also includes providing a first forward to aft ratio of electric power to the plurality of forward and aft propulsors. The method also includes moving the plurality of forward and aft propulsors to a forward thrust position. While in the forward thrust positions, the method also includes providing a second forward to aft ratio of electric power to the plurality of forward and aft propulsors. The first forward to aft ratio of electric power is different than the second forward to aft ratio of electric power to provide certain efficiencies for the aircraft.

Embodiments are directed to adding wing extensions outboard of the engine nacelles on tiltrotor aircraft to increase cruise efficiency. By using pivoting wing extensions, the download penalty during hover operations is decreased because the wing extensions will pivot into the downwash rather than act as a barrier. Freely pivoting wing extensions will align with the local airflow during conversion mode flight, which eliminates flow separation issues. The freely pivoting wing extensions also reduce gust response by rotating out of the way of turbulence and updrafts. A trailing edge trim flap provides simple and effective control of the incidence angle for the free-pivot wing extension.

Transitioning quadcopters and tricopters use passively adjusting tiltwings to reduce the number of actuators needed to control flight. Both transitioning copters can operate with four controlled actuators comprising four motor speeds for the quadcopter and three motor speeds and one rudder position for the tricopter.

Embodiments include an apparatus comprising an aircraft wing and a trailing edge aerodynamic surface connected to a trailing edge of the aircraft wing via a piston assembly in which the piston assembly holds the trailing edge aerodynamic surface in a neutral position relative to the aircraft wing at a constant supply pressure. The piston assembly may be implemented using a pneumatic piston or a hydraulic piston. A first end of the piston assembly may be connected to the aircraft wing and a second end of the piston assembly may be connected to the trailing edge aerodynamic surface. The piston assembly may include a pressure relief valve which may open or close, raising or lowering the aerodynamic surface, responsive to lift load on the aircraft wing.

A high-efficiency, stall-proof airfoil is an aircraft wing configuration whereby a motive force directly induces gaseous fluid flow across a lifting surface of the airfoil without requiring a movement of the wing through an air space. The airfoil is provided with means to control a pitch, a roll and a yaw motion and to control a position and stability of the aircraft. When not undergoing horizontal displacement, it provides highly efficient use of fuel resources, precluding the formation of drag and its incumbent power consumption. Air pressure at a bottom of the wing remains essentially ambient. Therefore, differential pressure between a lower surface of the wing and an upper surface of the wing maintains its maximum possible quantity. Virtually, all of the power consumed is utilized in a production of lift. Additionally, because lift is generated without regard to an angle-of-attack, forward speed, nor a configuration of a leading edge of the wing, the configuration is essentially stall proof.

An aircraft convertible between fixed-wing and hovering orientations includes a fuselage. The aircraft includes a main wing pair comprising two opposing wings attached to the fuselage, where each wing of the two opposing wings includes a fixed wing section attached to the fuselage and a movable wing section rotatably mounted to the fixed wing section. The aircraft includes at least a first propulsor mounted to the movable wing section of each of the two opposing wings. The aircraft includes at least a first rotation mechanism attached to the fixed wing section and movable wing section of each of the two opposing wings, the at least a first rotation mechanism configured to rotate the movable wing section between a first movable wing section position parallel to the fixed wing section and a second movable wing section position perpendicular to the fixed wing section.