When a fluid flows around an object, the fluid exerts a force on the object. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the force parallel to the flow direction. Lift conventionally acts in an upward direction in order to counter the force of gravity, but it is defined to act perpendicular to the flow and therefore can act in any direction.
In fluid dynamics, a stall is a reduction in the lift coefficient generated by a foil as angle of attack increases. This occurs when the critical angle of attack of the foil is exceeded. The critical angle of attack is typically about 15°, but it may vary significantly depending on the fluid, foil, and Reynolds number.
An airfoil or aerofoil is a streamlined body that is capable of generating significantly more lift than drag. Wings, sails and propeller blades are examples of airfoils. Foils of similar function designed with water as the working fluid are called hydrofoils.
In fluid dynamics, the lift coefficient is a dimensionless quantity that relates the lift generated by a lifting body to the fluid density around the body, the fluid velocity and an associated reference area. A lifting body is a foil or a complete foil-bearing body such as a fixed-wing aircraft. CL is a function of the angle of the body to the flow, its Reynolds number and its Mach number. The section lift coefficient cl refers to the dynamic lift characteristics of a two-dimensional foil section, with the reference area replaced by the foil chord.
A paper plane is a toy aircraft, usually a glider, made out of single folded sheet of paper or paperboard. It typically takes the form of a simple nose-heavy triangle thrown like a dart.
A supercritical aerofoil is an airfoil designed primarily to delay the onset of wave drag in the transonic speed range.
In aeronautics and aeronautical engineering, camber is the asymmetry between the two acting surfaces of an airfoil, with the top surface of a wing commonly being more convex. An airfoil that is not cambered is called a symmetric airfoil. The benefits of cambering were discovered and first utilized by George Cayley in the early 19th century.
NACA stands for the National Advisory Committee for Aeronautics, which was a U.S. federal agency founded in 1915 to undertake, promote, and institutionalize aeronautical research. It played a crucial role in advancing aviation technology, including the development of airfoils, which are the cross-sectional shapes of wings and other aerodynamic surfaces. The NACA airfoil series is a set of standardized airfoil shapes developed by this agency, which became widely used in the design of aircraft wings.
The Viking Dragonfly is an American amateur-built aircraft, designed by Bob Walters and produced by Viking Aircraft LLC of Elkhorn, Wisconsin. The aircraft is supplied as a kit or as plans for amateur construction.
The Yakovlev Yak-50 aerobatic aircraft is a single-seat all-metal low-wing monoplane with retractable main wheels and exposed tail wheel. The control surfaces are fabric-covered to save weight. The aircraft is not equipped with flaps.
The General Aviation GA-43 was a single engine low-wing monoplane airliner produced in small numbers in the United States in the mid-1930s, also known as the Pilgrim 150, Fairchild 150, and sometimes but erroneously as the Clark GA-43 for the designer, Virginius E. Clark who was also responsible for the Clark Y airfoil section used.
The Polikarpov I-3 was a Soviet fighter designed during the late 1920s. It entered service in 1929, but was retired in 1935 with the advent of fighters with higher performance.
The Gloster IV was a British racing floatplane of the 1920s. A single-engined biplane, the Gloster IV was a development of the earlier Gloster III intended to compete in the 1927 Schneider Trophy race. One aircraft competed in the race, but retired part way through. The three aircraft built continued to be used as trainers by the High Speed Flight for several years.
The Blue Yonder EZ Flyer is a Canadian-designed-and-built, tandem two-seat, open cockpit, pusher configuration, recreational and training aircraft provided as a completed aircraft or in kit form by Blue Yonder Aviation.
The Hall XP2H-1 was an American prototype four-engined biplane flying boat of the 1930s. Intended as an experimental very-long-range maritime patrol aircraft, a single example was built. The XP2H-1 was the largest four engine biplane aircraft ever procured by the US Navy.
The Star Cavalier was an American two-seat high-wing light aircraft first introduced in the late 1920s.
A supersonic airfoil is a cross-section geometry designed to generate lift efficiently at supersonic speeds. The need for such a design arises when an aircraft is required to operate consistently in the supersonic flight regime.
The Kline–Fogleman airfoil or KF airfoil is a simple airfoil design with single or multiple steps along the length of the wing. It was originally devised in the 1960s for paper airplanes.
The Stolp SA-900 V-Star is an American aerobatic homebuilt biplane, currently produced by Aircraft Spruce & Specialty Co in the form of plans for amateur construction. In the 1990s it was also available as a kit from Stolp Starduster Corporation of Riverside, California.
The Politechnika Warszawska PW-4 Pelikan was a motor-glider variant of the two seat Polish PW-3 Bakcyl glider. Only one flew.
