Slats are small aerodynamic surfaces on the leading edge of an airplane wing which, when deployed, allow the wing to operate at a higher angle of attack. Lift is a product of angle of attack and speed, so by deploying slats an aircraft can fly slower or take off and land in a shorter distance. They are usually used while landing or performing manoeuvres which take the aircraft close to the stall, but are usually retracted in normal flight to minimise drag. Fixed-wing aircraft is a term used to refer to what are more commonly known as aeroplanes in Commonwealth English (excluding Canada) or airplanes in North American English. ... A Laughing Gull on the beach in Atlantic City. ... In this diagram, the black arrow represents the direction of the wind. ... Lift consists of the sum of all the fluid dynamic forces on a body perpendicular to the direction of the external flow around that body. ... In aerodynamics, a stall is a condition in which an excessive angle of attack causes loss of lift due to disruption of airflow. ...

The position of the leading edge slats on an airliner (Airbus A310). In this picture, the slats are extended.

Types include: Download high resolution version (600x809, 90 KB)The position of the leading edge slats on an airliner (Airbus A300). ... Download high resolution version (600x809, 90 KB)The position of the leading edge slats on an airliner (Airbus A300). ...

• Automatic - the slat lies flush with the wing leading edge until reduced aerodynamic forces allow it to extend by way of springs when needed. This type is typically used on light aircraft.
• Fixed - the slat is permanently extended. This is rarely used, except on specialist low-speed aircraft (see: slot).
• Powered - the slat extension can be controlled by the pilot. This is commonly used on airliners.

The chord of the slat is typically only a few percent of the wing chord. They may extend over the outer third of the wing or may cover the entire leading edge. Slats work by increasing the camber of the wing, and also by opening a small gap (the slot) between the slat and the wing leading edge, allowing a small amount of high-pressure air from the lower surface to reach the upper surface, where it helps postpone the stall. A leading edge slot on a Stinson 108-3. ... In reference to aircraft, chord refers to the distance between the front and back of a wing, measured in the direction of the normal airflow. ...

The slat has a counterpart found in the wings of some birds, the alula – a feather or group of feathers which the bird can extend under control of its "thumb". For other meanings of bird, see bird (disambiguation). ... The alula, or bastard wing, is a small, feathered projection on the anterior edge of the wing of modern birds. ...

History

Slats were first developed by Handley-Page in 1919; licensing the design became one of their major sources of income in the 1920s. The original designs were in the form of a fixed slot in the front of the wing, a design that was found on a number of STOL aircraft. During World War II German aircraft commonly fitted a more advanced version that pushed back flush against the wing by air pressure to reduce drag, popping out on springs when the airflow decreased during slower flight. In the post-war era slats have generally been hydraulically or electrically operated, allowing for more complex and efficient designs. Slats is also a slang term for ribs. The Handley Page Aircraft Company was founded by Frederick Handley Page in 1909. ... 1919 (MCMXIX) was a common year starting on Wednesday (see link for calendar). ... Income, generally defined, is the money that is received as a result of the normal business activities of an individual or a business. ... Sometimes referred to as the Jazz Age or primarily in North America and in Australia as the Roaring Twenties . In Europe it is sometimes refered to as the Golden Twenties. ... STOL is an acronym for Short Take-Off and Landing, used in the aircraft industry to describe airplanes with very short runway requirements. ... Combatants Allied Powers Axis Powers Commanders {{{commander1}}} {{{commander2}}} Strength {{{strength1}}} {{{strength2}}} Casualties 17 million military deaths 7 million military deaths World War II, also known as the Second World War, was a mid-20th century conflict that engulfed much of the globe and is accepted as the largest and deadliest... Atmospheric pressure is the pressure caused by the weight of air above any area in the Earths atmosphere. ... For a solid object moving through a fluid or gas, drag is the sum of all the aerodynamic or hydrodynamic forces in the direction of the external fluid flow. ... Hydraulics is a branch of science and engineering concerned with the use of liquids to perform mechanical tasks. ... The article on electrical energy is located elsewhere. ...

Today slats are generally one of several high-lift devices used on airliners, complex flap systems running along the trailing edge of the wing as well. In aircraft design, high-lift devices are a variety of mechanisms intended to add lift during certain portions of flight. ... An airliner is a large fixed-wing aircraft (an aeroplane/airplane) initially designed for the transport of paying passengers, and usually operated by an airline company (which owns or leases the aircraft). ... Flaps are hinged surfaces on the trailing edge of an airplane wing which, when deployed, increase the lift (and drag) of a wing. ...

See also:

• Aviation
• Flight
• Flight controls

... Flight is the process of flying: either movement through the air by aerodynamically generating lift or aerostatically using buoyancy, or movement beyond earths atmosphere by spacecraft. ... It has been suggested that this article or section be merged with Aircraft flight mechanics. ...