An airfoil system is provided that includes an airfoil. This airfoil includes a first exterior surface, a second exterior surface, a first airfoil segment and a second airfoil segment. The airfoil extends widthwise between the first exterior surface and the second exterior surface. The first airfoil segment includes first composite material and a receptacle. A base of the receptacle is embedded within the first composite material. The second airfoil segment includes second composite material and a key. A base of the key is embedded within the second composite material. The key is mated with the receptacle thereby attaching the second airfoil segment to the first airfoil segment.

A composite structure includes a first composite skin and a second composite skin defining a longitudinal cavity therebetween. The first composite skin and the second composite skin further define at least one edge where the first composite skin contacts the second composite skin. The composite structure further includes at least one core disposed within the longitudinal cavity. The core includes a first surface and a second surface which define a core edge where the first surface contacts the second surface. The core is positioned with the core edge adjacent the at least one edge with the first surface contacting the first composite skin and the second surface contacting the second composite skin.

An airfoil body is provided for an aircraft which includes a first skin, a second skin, a plurality of first stiffeners and a plurality of second stiffeners. The first stiffeners are configured from or otherwise include first stiffener composite material. The first stiffeners extends widthwise between and are connected to the first skin and the second skin. Each of the first stiffeners has a first stiffener longitudinal centerline that extends spanwise along the first skin and the second skin. The second stiffeners are configured from or otherwise include second stiffener composite material. The second stiffeners extend widthwise between and are connected to the first skin and the second skin. Each of the second stiffeners has a second stiffener longitudinal centerline that extends lengthwise along the first skin and the second skin.

An airfoil body is provided for an aircraft which includes a first skin, a second skin, a plurality of first stiffeners and a plurality of second stiffeners. The first stiffeners are configured from or otherwise include first stiffener composite material. The first stiffeners extends widthwise between and are connected to the first skin and the second skin. Each of the first stiffeners has a first stiffener longitudinal centerline that extends spanwise along the first skin and the second skin. The second stiffeners are configured from or otherwise include second stiffener composite material. The second stiffeners extend widthwise between and are connected to the first skin and the second skin. Each of the second stiffeners has a second stiffener longitudinal centerline that extends lengthwise along the first skin and the second skin.

A method for forming a fiber-reinforced thermoplastic control surface may comprise: stacking plies of thermoplastic composite sheets to a first desired thickness to form a first skin; stacking plies of thermoplastic composite sheets to a second desired thickness to form a second skin; forming the first skin in a first contour; forming the second skin in a second contour; forming a stiffening member including a thermoplastic resin, the stiffening member including a shape having a plurality of peaks and troughs; assembling the stiffening member between the first skin and the second skin; and joining the stiffening member to the first skin and the second skin.

A vertical take-off and landing (VTOL) aircraft has a first drivable configuration in which the pilot seat is positioned between the wings and facing the direction of forward travel. The VTOL may be driven in the first configuration as a normal automobile. In the first configuration the wings are aligned with the direction of forward travel and their surfaces are vertically oriented. In the first configuration, the VTOL may also attain altitude and be maneuvered using thrust from propulsion sources. In a second configuration, the pilot seat is rotated 90 degrees from the direction of forward travel to a direction of forward flight. Forward flight is achieved using thrust to rotate the wings from the vertical orientation to a lift-providing orientation. In concert with the rotation of the wings, the pilot seat is counter-rotated to maintain the seat facing the direction of forward flight.

A manufacturing method of a control surface of an aircraft, the control surface including an upper skin, a lower skin, ribs joining the upper skin and the lower skin and located along a chordwise direction of the control surface. The manufacturing method includes the steps of providing a single composite preform comprising the upper skin, the lower skin and the ribs, and curing the single composite preform such that an integrated box comprising the upper skin, the lower skin and the ribs is formed.

A method of forming a structural honeycomb includes cutting and folding a substrate sheet according to predetermined cutting and folding patterns and fold angles that cause the sheet to form a honeycomb having cells that each have at least one face abutting, or nearly abutting, the face of another cell. The honeycomb is then stabilized by joining abutting, or nearly abutting, faces to hold the honeycomb together. The honeycomb may have a prespecified three-dimensional shape. The folding pattern may include corrugation, canted corrugation, or zig-zag folds. Joining may employ fixed and/or reversible joinery, including slotted cross section, tabbed strip, angled strip, integral skin, sewn, or laced. At least some folds may be partially-closed to create bends and twists in the honeycomb structure. Some surfaces of the honeycomb may be covered with a skin or face sheet. The substrate sheet may have flexible electronic traces.

A method of forming a structural honeycomb includes cutting and folding a substrate sheet according to predetermined cutting and folding patterns and fold angles that cause the sheet to form a honeycomb having cells that each have at least one face abutting, or nearly abutting, the face of another cell. The honeycomb is then stabilized by joining abutting, or nearly abutting, faces to hold the honeycomb together. The honeycomb may have a prespecified three-dimensional shape. The folding pattern may include corrugation, canted corrugation, or zig-zag folds. Joining may employ fixed and/or reversible joinery, including slotted cross section, tabbed strip, angled strip, integral skin, sewn, or laced. At least some folds may be partially-closed to create bends and twists in the honeycomb structure. Some surfaces of the honeycomb may be covered with a skin or face sheet. The substrate sheet may have flexible electronic traces.

Provided herein is a method to reinforce a junction of fiber-composite aircraft components forming an elongate conduit. The method comprises (a) abrading the junction and (b) applying sealant along the junction from a tool moveable through the conduit, the tool exerting force on an interior surface of the conduit opposite the junction.