A method of determining an initial leading edge circle for airfoils of a blade and of improving a blade, and also an improved blade and a advancement propeller including the improved blade. The radius of the initial leading edge circle of each airfoil of the blade is determined and then increased, and its leading edge is moved away from a pressure side half-airfoil towards a suction side half-airfoil, thereby modifying the airfoil of each cross-section of the blade and modifying the camber of each airfoil. Consequently, the absolute value of the negative stall angle of attack of the blade is increased, thus making it possible to increase the aerodynamic performance of the blade under a negative angle of attack compared with a blade that is not modified, and without significantly degrading its aerodynamic performance under a positive angle of attack.

A wing tip device for a fixed wing aircraft is disclosed having an alular-like projection, a first leading edge region having a first sweep angle, a second leading edge region outboard of the first leading edge region in a spanwise direction and having a second sweep angle greater than the first sweep angle, a third leading edge region outboard of the second leading edge region in the spanwise direction and adjacent a tip end of the wing tip device and having a third sweep angle greater than the first sweep angle. The second leading edge region is adapted to generate a first vortex, and the third leading edge region is adapted to generate a second vortex which builds towards the tip end of the wing tip device.

Disclosed herein is a VTOL tilt-wing aircraft that serves as a 4-6 passenger airliner for scheduled service between city centers and that is optimized for travel distances from 100-500 miles fully loaded with passengers and fuel. The VTOL aircraft solves technical, cost, and time problems inherent in other forms of transportation, including, but not limited to, rail, passenger airlines, and helicopters. The VTOL aircraft (1) takes off and lands like a helicopter, (2) flies fast like a jet, and (3) costs less than or comparable to a helicopter.

A wing for an aircraft, including a main wing, a slat, and a connection assembly movably connecting the slat to the main wing, the slat movable between a retracted and at least one extended position. The connection assembly includes an elongate slat track. A wing has a connection assembly without requiring the front spar being penetrated. The slat track has a first end mounted to the slat and a second end guided at the main wing for movement along a predetermined path extending in a direction from a front spar to a leading edge of the main wing and from a lower side to an upper side of the main wing. Between the first and second ends the slat track is mounted to the main wing allowing translation of the slat track and rotation of the slat track about a first axis of rotation parallel to the leading edge.

A wing comprising a fixed main part and a leading edge slat with upper and lower surface rear edges. The wing main part has an upper surface wall, which extends downstream and in alignment with the upper surface rear edge, and a lower surface wall, which extends downstream and in alignment with the lower surface rear edge. The wing has an upper surface gap between the end of the upper surface rear edge and the end of the upper surface wall and a lower surface gap between the end of the lower surface rear edge and the end of the lower surface wall. The wing has an upper surface channel downstream of the upper surface gap and a lower surface channel downstream of the lower surface gap. The wing comprises a suction system connected to each channel and arranged to suck the air contained in the channel.

Continuous skin leading edge slats are disclosed. A disclosed example leading edge slat for use with an aircraft includes a single-piece nose skin defining upper and lower external surfaces of the leading edge slat, where the single-piece nose skin is to extend between a fore end and an aft end of the leading edge slat, and a box spar coupled to an inner surface of the single-piece nose skin. The box spar includes lateral walls extending away from the inner surface of the single-piece nose skin. The lateral walls define at least one compartment of the box spar.

An impingement cooling system is disclosed, including an airfoil having an aerodynamically sharp leading edge, a fluid source, and a fluid dispersal device connected to the fluid source. The leading edge has a concave internal surface and the fluid dispersal device is configured to project a fluctuating stream of fluid toward the internal surface.

A leading edge skin panel for an aerodynamic structure of an aircraft. The skin panel includes attachment components for attaching the leading edge skin panel to the structure. A primary attachment component is configured to substantially prevent spanwise relative movement between the leading edge skin panel and the structure. The remaining attachment component are configured to permit a predetermined amount of spanwise relative movement between the leading edge skin panel and the structure.

An airflow profiled structure having a profiled leading edge. The profiled leading edge having, along a leading edge line, a serrated profile line with a succession of teeth and depressions. The airflow profiled structure also includes a porous acoustically absorbent region located towards the bottom of the depressions.

Various embodiments of an airfoil and machines with airfoils are disclosed. The airfoils include a thicker leading airfoil portion and a thinner trailing airfoil portion. In one embodiment, the leading airfoil portion is formed by bending a body of the airfoil back toward itself. In another embodiment, the leading airfoil portion has a solid geometry and includes two elliptic surfaces. To prevent detachment of airflow, the leading airfoil portion includes at least two arc portions or surfaces that act to direct the airflow down to the trailing airfoil portion in a manner that stabilizes vortexes that may form in the region of changing thickness.