angle of attack

The drag equation may be derived to within a multiplicative constant by the method of dimensional analysis. If a moving fluid meets an object, it exerts a force on the object, according to a complicated (and not completely understood) law. We might suppose that the variables involved under some conditions to be the speed, density and viscosity of the fluid, the size of the body (expressed in terms of its frontal area A), and the drag force. Using the algorithm of the π-theorem, one can reduce these five variables to two dimens ...

See also:

Drag equation, Drag equation - Derivation of the drag equation

Read more here: » Drag equation: Encyclopedia II - Drag equation - Derivation of the drag equation

An angle of incidence is the angle between a beam incident on a surface and the normal (line perpendicular to the surface at the point of incidence). The beam can be formed by any wave: optical, acoustical, microwave, X-ray etc. In Fig.1 the red line representing a ray makes an angle θ with the normal (dotted line). Another common usage is in aviation, where it refers to the angle between the wing's chord (aircraft) and the longitudinal axis of an aircraft (a fixed value). Fig.2 shows a side view of part of an ae ...

Including:

• Angle of incidence - Optics
• Angle of incidence - Aviation

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Dihedral is the upward angle of an aircraft's (or bird's) wings from root to tip, as viewed from directly in front of or behind the aircraft. Downward angled wings are said to have anhedral. The purpose of dihedral is to confer stability in the roll axis. A popular but erroneous explanation for how it works is that if the aircraft is perturbed such that one wing is lowered relative to the other, dihedral causes the lower wing to increase its surface area relative to the airflow, thus increasing its lift. This acts to opp ...

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An Aeroplane (Airplane in US usage), is defined as: a power-driven heavier than air Aircraft, deriving its lift chiefly from aerodynamic reactions on surface which remain fixed under given conditions of flight. (ICAO Doc 9110) Aircraft flight mechanics - Straight and level flight of airplane. In steady, level flight, an airplane can be considered as being acted on by four forces in equilibrium: lift, weight, thrust, and drag. Thrust is the force generated by the engine and acts along the engine's thr ...

Including:

• Aircraft flight mechanics - Straight and level flight of airplane
• Aircraft flight mechanics - Airplane control and movement
• Aircraft flight mechanics - Airplane control surfaces
• Aircraft flight mechanics - Aerodynamics

Read more here: » Aircraft flight mechanics: Encyclopedia - Aircraft flight mechanics

Oscillation is the periodic variation, typically in time, of some measure as seen, for example, in a swinging pendulum. The term vibration is sometimes used more narrowly to mean a mechanical oscillation but sometimes is used to be synonymous with oscillation. Oscillations occur not only in physical systems but also in biological systems and in human society. Oscillations are the origin of the sensation of musical tone. Oscillation - Simple systems. The simplest oscillating system is a mass, s ...

Including:

• Oscillation - Simple systems
• Oscillation - Damped driven and self-excited oscillations
• Oscillation - Self-exciting systems
• Oscillation - Coupled oscillations
• Oscillation - Continuous systems - waves
• Oscillation - Neural systems
• Oscillation - Examples
• Oscillation - Mechanical
• Oscillation - Electrical
• Oscillation - Electro-mechanical
• Oscillation - Biological
• Oscillation - Human
• Oscillation - Economic and social
• Oscillation - Climate and geophysics

Read more here: » Oscillation: Encyclopedia - Oscillation

Autorotations are used in helicopters to perform power off landings from altitude in the event of an engine failure. Autorotation is also used in autogyro aircraft as the main means of achieving lift during normal operation. See autogyro for more information. Autorotation - Maneuver Description. An autorotation is used when the engine fails, or when a tail rotor failure requires the pilot to effectively shut down the engine. It is very similar to gliding in an airplane. The e ...

Including:

• Autorotation - Maneuver Description
• Autorotation - Common Mistakes

Read more here: » Autorotation: Encyclopedia - Autorotation

A wing is a surface used to produce an aerodynamic force normal to the direction of motion by travelling in air or another gaseous medium, facilitating flight. It is a specific form of airfoil. The first use of the word was for the foremost limbs of birds, but has been extended to include the wings of Insects, bats and pterosaurs; also man-made devices. A wing is an extremely efficient device for generating lift. Its aerodynamic quality, expressed as a Lift-to-drag ratio, can be up to 60 on some gliders and even more. Th ...

Including:

• Wing - Use
• Wing - Artificial wings
• Wing - Terms used to describe aeroplane wings
• Wing - Design features
• Wing - Wing types
• Wing - Science of wings
• Wing - Evolution of wings in animals

Read more here: » Wing: Encyclopedia - Wing

An aerofoil ( in British English, or airfoil in American English, ) is the shape of a wing or blade (of a propeller or ship's screw or sail) as seen in cross-section. It is passed through a fluid in order to provide either lift or downforce, depending on its application. Subsonic-flight aerofoils have a characteristic shape with a rounded leading edge, followed by a sharp trailing edge, and often with camber. To understand lift itself, see lift. As well as the wing, an aircraft's horizontal and vertical stabilizers are a ...

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In aerodynamics, wing loading is the loaded weight of the aircraft divided by the area of the wing. It is broadly reflective of the aircraft's lift-to-mass ratio, which affects its rate of climb, load-carrying ability, and turn performance. Typical wing loadings range from 20 lb/ft² (100 kg/m²) for general aviation aircraft, to 80 to 120 lb/ft² (390 to 585 kg/m²) for high-speed designs like modern fighter aircraft. Wings generate lift owing to the motion of air over the wing surface. Larger wings move more air, so an ...

Read more here: » Wing loading: Encyclopedia - Wing loading

ρ The lift coefficient (CL) is a number associated with a particular shape of an airfoil, and is incorporated in the lift equation to predict the lift force generated by a wing using this particular cross section. The lift coefficient CL is equal to: where L is the lift force, ρ< ...

Read more here: » Lift coefficient: Encyclopedia - Lift coefficient

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. These front and back points are referred to as the leading edge and trailing edge. Most wings change their chord over their width (or span). To give a characteristic figure which can be compared among various wing shapes, the mean aerodynamic chord, or MAC, is used. The MAC is somewhat more complex to calculate, because most wings vary in area over the s ...

Read more here: » Chord aircraft: Encyclopedia - Chord aircraft

Camber may refer to: Camber, East Sussex, a seaside resort in England, near to Camber Sands. Royal Camber Lawn Tennis Club - Dulwich Village Tennis Club in London Camber also has slightly different meanings in different technical fields: See camber angle for the use of the term in automobile technology In aeronautical engineering camber is the asymmetry between the top and the bottom curves of an aerofoil. Cambered aerofoils generate lift at positive, zero, or eve ...

Read more here: » Camber: Encyclopedia - Camber

Flight is the mode of locomotion used by most of the world’s bird species. It is important to birds for feeding, breeding and avoiding predators. Bird flight - Evolution and purpose of bird flight. The origin of bird flight is still somewhat unclear, even though most paleontologists agree that birds evolved from small theropod dinosaurs. It seems likely that they evolved from ground living species, with flight developing after the evolution of feathers. It seems likely in this case that flight evol ...

Including:

• Bird flight - Evolution and purpose of bird flight
• Bird flight - Basic mechanics of bird flight
• Bird flight - The wing
• Bird flight - Wing shape and flight
• Bird flight - Elliptical wings
• Bird flight - High speed wings
• Bird flight - High aspect ratio wings
• Bird flight - Soaring wings with deep slots
• Bird flight - Hovering
• Bird flight - Take-off and landing
• Bird flight - Adaptations for flight

Read more here: » Bird flight: Encyclopedia - Bird flight

A helicopter is an aircraft which is lifted and propelled by one or more horizontal rotors (propellers). Helicopters are classified as rotary-wing aircraft to distinguish them from conventional fixed-wing aircraft. The word helicopter is derived from the Greek words helix (spiral) and pteron (wing). The engine-driven helicopter was invented by the Slovak inventor Jan Bahyl. The first stable, fully-controllable helicopter pl ...

Including:

• Helicopter - Applications
• Helicopter - History
• Helicopter - Generating lift
• Helicopter - Conventional layout
• Helicopter - Alternative layouts
• Helicopter - Controlling flight
• Helicopter - Stability
• Helicopter - Limitations
• Helicopter - Landing
• Helicopter - On a ship
• Helicopter - Hazards of helicopter flight
• Helicopter - Helicopter models and identification

Read more here: » Helicopter: Encyclopedia - Helicopter

A biplane is a fixed-wing aircraft with two main wings of similar spans, normally one mounted above, and the other level with the underside of the fuselage. The upper wing normally overlaps the lower wing, and vertical or slightly raked slender struts are often positioned symmetrically on either side of the fuselage (connecting the rigid sections of the upper and lower wings into a stong box structure). When the upper and lower wing overlap only partially, this is known as stagger; it is designed to minimise aerodynamic interference b ...

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A waverider is a hypersonic aircraft design that improves its supersonic lift-to-drag ratio by producing a lifting surface built out of the shock waves being generated by its own flight, a technique known as compression lift. To date the only aircraft to use the technique is the supersonic XB-70 Valkyrie, although it was not a waverider. The waverider remains a well-studied design for high-speed aircraft in the Mach 5 and higher hypersonic regime, although no ...

Including:

• Waverider - History
• Waverider - Design

Read more here: » Waverider: Encyclopedia - Waverider

In unpowered flight, rising air is needed to keep a glider aloft. This rising air can come from two sources: when the sun heats features on the ground, columns of rising air known as thermals are generated when wind encounters a ridge in the landscape, the air is forced upwards, providing ridge lift. In mountainous environments, flying is mostly based around thermals, which can be used to stay aloft before heading for a landing field below the launch site. In hill environments, ridge lift is use ...

See also:

Paragliding, Paragliding - Gliders, Paragliding - Flying, Paragliding - Ridge soaring, Paragliding - Thermal flying, Paragliding - Cross-country flying, Paragliding - Launching / landing, Paragliding - Control of the glider, Paragliding - Collapses, Paragliding - Sports/competitive flying, Paragliding - Safety, Paragliding - Learning to fly, Paragliding - World records, Paragliding - History, Paragliding - Comparison with hang gliders

Read more here: » Paragliding: Encyclopedia II - Paragliding - Flying

In conventional aircraft, the wing profile (called airfoil) is designed to have a shape where the bottom surface has a shorter path than the top surface. The longer path that the fluid (in this case air) must travel across the top surface equates to a higher speed. The higher the speed of a fluid, the lower the dynamic pressure (as opposed to static pressure) on the surface. Thus, by causing the air to flow faster over the top surface than the bottom, the airfoil causes a pressure difference directed upward. This pressure difference integrat ...

See also:

Helicopter, Helicopter - Applications, Helicopter - History, Helicopter - Generating lift, Helicopter - Conventional layout, Helicopter - Alternative layouts, Helicopter - Controlling flight, Helicopter - Stability, Helicopter - Limitations, Helicopter - Landing, Helicopter - On a ship, Helicopter - Hazards of helicopter flight, Helicopter - Helicopter models and identification

Read more here: » Helicopter: Encyclopedia II - Helicopter - Generating lift

Messerschmitt Bf 109 - Bf 109A/B/C. The planned Bf 109A series was canceled before production begun, because of its weak armament (it was planned to have only two nose-mounted machine guns). Instead of this, the Bf 109 V4 was constructed, carrying a third MG 17, mounted behind the engine, firing through the propeller axis. In the following three prototype planes (V5, V6, V7), the new Jumo 210B engine was installed. They also were armed with three machine guns and were identical ...

See also:

Messerschmitt Bf 109, Messerschmitt Bf 109 - Designation, Messerschmitt Bf 109 - Contest history, Messerschmitt Bf 109 - Design Features, Messerschmitt Bf 109 - Prototypes, Messerschmitt Bf 109 - The Contest, Messerschmitt Bf 109 - Models, Messerschmitt Bf 109 - Bf 109A/B/C, Messerschmitt Bf 109 - Bf 109D Dora, Messerschmitt Bf 109 - Bf 109E Emil, Messerschmitt Bf 109 - Bf 109F Friedrich, Messerschmitt Bf 109 - Bf 109G Gustav, Messerschmitt Bf 109 - Bf 109H, Messerschmitt Bf 109 - Bf 109K Kurfürst, Messerschmitt Bf 109 - Bf 109T Trägerflugzeug Carrier Aircraft, Messerschmitt Bf 109 - Bf 109Z Zwilling, Messerschmitt Bf 109 - Bf 109W Wasserfluzeug projekt, Messerschmitt Bf 109 - Developments after the war, Messerschmitt Bf 109 - Operators

Read more here: » Messerschmitt Bf 109: Encyclopedia II - Messerschmitt Bf 109 - Models

A conventional aircraft is able to fly because the forward motion of the angled wings creates lift by seperating the air into two streams. One stream of air goes over the wing and one goes under. Because the air traveling over the top of the wing has a longer distance to travel, due to the curve on the upper part of the wing, (called camber) and because the air traveling over the top and bottom of the wing wants to meet at the same time, the air flowing over the top of the wing has to travel at a faster rate than the air flowing over the bot ...

See also:

Helicopter, Helicopter - Applications, Helicopter - History, Helicopter - Generating lift, Helicopter - Conventional layout, Helicopter - Alternative layouts, Helicopter - Controlling flight, Helicopter - Stability, Helicopter - Limitations, Helicopter - Landing, Helicopter - On a ship, Helicopter - Hazards of helicopter flight, Helicopter - Helicopter models and identification

Read more here: » Helicopter: Encyclopedia II - Helicopter - Generating lift