A fixed wing aircraft has a wing with an aerofoil cross-section defining an upper and lower geometric surfaces which meet at a geometric leading edge of the wing. The wing has an upper and lower aerodynamic surfaces while in flight. The upper aerodynamic surface and the lower aerodynamic surface meet at an aerodynamic leading edge at the intersection with an attachment line dividing the air that passes over the upper aerodynamic surface from the air that passes over the lower aerodynamic surface. The lower geometric surface adjacent the geometric leading edge has a roughness strip with a step height of at least 50 microns over the lower geometric surface. The roughness strip is located on the lower aerodynamic surface of the wing when the aircraft is flown at a load factor of 1 g and is located on the upper aerodynamic surface when the load factor is above 1.2 g.

Systems for removing gas from a sealant and transferring gas-less sealant to an applicator are provided. The system may comprise: a rotatable chamber including: a first opening for receiving sealant; a hollow conduit arranged such that when gas accumulates in the center of the rotatable chamber when the rotatable chamber is rotating, the gas is ventable from the rotatable chamber; a second opening for receiving gas-less sealant from the rotatable chamber after the gas is vented from the hollow conduit; and a motor operatively configured to rotate the rotatable chamber; and a gas-less sealant applicator in fluid communication with the second opening of the rotatable chamber such that gas-less sealant released by the second opening is flowable into the applicator. The system may also include a robot arm including an end effector with a sealant dispensing nozzle. A method for applying sealant to an aircraft structure is also provided.

Systems for removing gas from a sealant and transferring gas-less sealant to an applicator are provided. The system may comprise: a rotatable chamber including: a first opening for receiving sealant; a hollow conduit arranged such that when gas accumulates in the center of the rotatable chamber when the rotatable chamber is rotating, the gas is ventable from the rotatable chamber; a second opening for receiving gas-less sealant from the rotatable chamber after the gas is vented from the hollow conduit; and a motor operatively configured to rotate the rotatable chamber; and a gas-less sealant applicator in fluid communication with the second opening of the rotatable chamber such that gas-less sealant released by the second opening is flowable into the applicator. The system may also include a robot arm including an end effector with a sealant dispensing nozzle. A method for applying sealant to an aircraft structure is also provided.

An aircraft comprising a wing having a spanwise lift distribution extending from a root to a tip, the lift distribution defining an inboard region defining a positive lift contribution, an outboard region defining a negative lift contribution, and an intermediate region defining a neutral lift contribution, the neutral region being spaced from the tip and from the root. A propulsion system is provided, comprising a wing mounted propulsor. The wing mounted propulsor has a rotational axis (x) positioned substantially at a span of the wing where a value of δLift/δSpan is at a maximum for the span of the wing, and may be located at the intermediate region along the span of the wing.

A fluid adjustment device is provided with: a body part mounted on a wing tip, which is an end part of a main wing on the opposite side to the wing root, and having an upper opening and a lower opening formed in an upper surface of the body part and a lower surface of the body part; a first Francis turbine that sucks air from the upper opening and the lower opening and discharges the sucked air from the trailing edge side of the main wing; and a first motor for rotating the first Francis turbine in a direction opposite to a rotation direction of a wingtip vortex generated at the wingtip. The first Francis turbine has a central axis extending from the leading edge of the main wing toward the trailing edge, sucks air from the circumferential direction, and discharges the sucked air in the axial direction.

A transport carriage for wings that are secured together, wherein the transport carriage comprises a chassis mounted on wheels, cradles mounted on positioning cylinders, support cylinders that each have a support mounted on the stem of the support cylinder, a central support having a frame and, for each wing, a rotatable lateral cradle, wherein the frame is movable vertically, for each wing, a lifting system with a mast and an arm, wherein each arm is movable vertically on the mast between a low position and a high position, and for each arm, at least two bearing points for the wing. The use of different movable elements allows good loading of the wings and makes it easier to move the wings thus loaded.

In one embodiment, a method includes fastening a plurality of components of a composite structure in an assembly fixture, wherein the assembly fixture comprises a plurality of strands of a fiber-reinforced thermoplastic material, wherein the fiber-reinforced thermoplastic material comprises a thermoplastic embedded with a plurality of reinforcement fibers, wherein the plurality of reinforcement fibers is aligned within each strand of the plurality of strands, and wherein the assembly fixture further comprises an anisotropic thermal expansion property based on an orientation of the plurality of reinforcement fibers within the assembly fixture; and heating the assembly fixture in an autoclave to bond the plurality of components of the composite structure.

In one embodiment, a method includes fastening a plurality of components of a composite structure in an assembly fixture, wherein the assembly fixture comprises a plurality of strands of a fiber-reinforced thermoplastic material, wherein the fiber-reinforced thermoplastic material comprises a thermoplastic embedded with a plurality of reinforcement fibers, wherein the plurality of reinforcement fibers is aligned within each strand of the plurality of strands, and wherein the assembly fixture further comprises an anisotropic thermal expansion property based on an orientation of the plurality of reinforcement fibers within the assembly fixture; and heating the assembly fixture in an autoclave to bond the plurality of components of the composite structure.

A combination of an airfoil, turbine blade, or compressor blade with a flow separation control device includes an airfoil, a flow separation control device, and an injection system. The airfoil includes a body with an upper surface and a lower surface that extend from a leading edge to a trailing edge. The flow separation control device includes a plurality of openings on the upper surface of the body. The injection system includes an inlet tube, a pump in gaseous communication with the inlet tube, and a flow regulator in gaseous communication with the pump and the plurality of capillary tube.

A combination of an airfoil, turbine blade, or compressor blade with a flow separation control device includes an airfoil, a flow separation control device, and an injection system. The airfoil includes a body with an upper surface and a lower surface that extend from a leading edge to a trailing edge. The flow separation control device includes a plurality of openings on the upper surface of the body. The injection system includes an inlet tube, a pump in gaseous communication with the inlet tube, and a flow regulator in gaseous communication with the pump and the plurality of capillary tube.