Aircraft

Aircraft

Overview


An aircraft is a vehicle
Vehicle
A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....

 that is able to fly
Flight
Flight is the process by which an object moves either through an atmosphere or beyond it by generating lift or propulsive thrust, or aerostatically using buoyancy, or by simple ballistic movement....

 by gaining support from the air, or, in general, the atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...

 of a planet. An aircraft counters the force of gravity by using either static lift
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...

 or by using the dynamic lift
Lift (force)
A fluid flowing past the surface of a body exerts a surface force on it. 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 surface force parallel to the flow direction...

 of an airfoil
Airfoil
An airfoil or aerofoil is the shape of a wing or blade or sail as seen in cross-section....

, or in a few cases the downward thrust from jet engines.

Although rocket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

s and missile
Missile
Though a missile may be any thrown or launched object, it colloquially almost always refers to a self-propelled guided weapon system.-Etymology:The word missile comes from the Latin verb mittere, meaning "to send"...

s also travel through the atmosphere, most are not considered aircraft because they do not have wings and rely on rocket thrust as the primary means of lift.

The human
Human
Humans are the only living species in the Homo genus...

 activity that surrounds aircraft is called aviation
Aviation
Aviation is the design, development, production, operation, and use of aircraft, especially heavier-than-air aircraft. Aviation is derived from avis, the Latin word for bird.-History:...

.
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Encyclopedia


An aircraft is a vehicle
Vehicle
A vehicle is a device that is designed or used to transport people or cargo. Most often vehicles are manufactured, such as bicycles, cars, motorcycles, trains, ships, boats, and aircraft....

 that is able to fly
Flight
Flight is the process by which an object moves either through an atmosphere or beyond it by generating lift or propulsive thrust, or aerostatically using buoyancy, or by simple ballistic movement....

 by gaining support from the air, or, in general, the atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...

 of a planet. An aircraft counters the force of gravity by using either static lift
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...

 or by using the dynamic lift
Lift (force)
A fluid flowing past the surface of a body exerts a surface force on it. 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 surface force parallel to the flow direction...

 of an airfoil
Airfoil
An airfoil or aerofoil is the shape of a wing or blade or sail as seen in cross-section....

, or in a few cases the downward thrust from jet engines.

Although rocket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

s and missile
Missile
Though a missile may be any thrown or launched object, it colloquially almost always refers to a self-propelled guided weapon system.-Etymology:The word missile comes from the Latin verb mittere, meaning "to send"...

s also travel through the atmosphere, most are not considered aircraft because they do not have wings and rely on rocket thrust as the primary means of lift.

The human
Human
Humans are the only living species in the Homo genus...

 activity that surrounds aircraft is called aviation
Aviation
Aviation is the design, development, production, operation, and use of aircraft, especially heavier-than-air aircraft. Aviation is derived from avis, the Latin word for bird.-History:...

. Manned aircraft are flown by an onboard pilot
Aviator
An aviator is a person who flies an aircraft. The first recorded use of the term was in 1887, as a variation of 'aviation', from the Latin avis , coined in 1863 by G. de la Landelle in Aviation Ou Navigation Aérienne...

. Unmanned aerial vehicle
Unmanned aerial vehicle
An unmanned aerial vehicle , also known as a unmanned aircraft system , remotely piloted aircraft or unmanned aircraft, is a machine which functions either by the remote control of a navigator or pilot or autonomously, that is, as a self-directing entity...

s may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as lift type, propulsion, usage, and others.

History


Flying model craft and stories of manned flight go back many centuries, however the first manned ascent - and safe descent - in modern times took place by hot-air balloon in the 18th century. Each of the two World Wars led to great technical advances. Consequently the history of aircraft development can be divided into five eras:
  • Pioneers of flight, from the earliest experiments to 1913.
  • First World War
    Aviation in World War I
    World War I was the first war in which aircraft were deployed on a large scale. Tethered observation balloons had already been employed in several wars, and would be used extensively for artillery spotting. Germany employed Zeppelins for reconnaissance over the North Sea and strategic bombing raids...

    , 1914 to 1918.
  • Inter-war, sometimes called the Golden Age
    Golden Age of Aviation
    The Golden Age of Aviation was the period between World War I and World War II in which civil aviation, fueled by many daring and dramatic record-breaking feats, became popularized...

    , 1919 to 1938.
  • Second World War
    Air warfare of World War II
    Air warfare of World War II was a major component of World War II in all theatres, and consumed a large fraction of the industrial output of the major powers....

    , 1939 to 1945.
  • Postwar era, also called the jet age
    Jet age
    The Jet Age is a period of history defined by the social change brought about by the advent of large aircraft powered by turbine engines. These aircraft are able to fly much higher, faster, and farther than older piston-powered propliners, making transcontinental and inter-continental travel...

    , 1946 to the present day.

Lighter than air – aerostats


Aerostat
Aerostat
An aerostat is a craft that remains aloft primarily through the use of buoyant lighter than air gases, which impart lift to a vehicle with nearly the same overall density as air. Aerostats include free balloons, airships, and moored balloons...

s use buoyancy
Buoyancy
In physics, buoyancy is a force exerted by a fluid that opposes an object's weight. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the...

 to float in the air in much the same way that ships float on the water. They are characterized by one or more large gasbags or canopies, filled with a relatively low-density gas such as helium
Helium
Helium is the chemical element with atomic number 2 and an atomic weight of 4.002602, which is represented by the symbol He. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table...

, hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...

, or hot air
Hot air balloon
The hot air balloon is the oldest successful human-carrying flight technology. It is in a class of aircraft known as balloon aircraft. On November 21, 1783, in Paris, France, the first untethered manned flight was made by Jean-François Pilâtre de Rozier and François Laurent d'Arlandes in a hot air...

, which is less dense than the surrounding air. When the weight of this is added to the weight of the aircraft structure, it adds up to the same weight as the air that the craft displaces.

Small hot-air balloons called sky lanterns date back to the 3rd century BC, and were only the second type of aircraft to fly, the first being kite
Kite
A kite is a tethered aircraft. The necessary lift that makes the kite wing fly is generated when air flows over and under the kite's wing, producing low pressure above the wing and high pressure below it. This deflection also generates horizontal drag along the direction of the wind...

s.

A balloon
Balloon (aircraft)
A balloon is a type of aircraft that remains aloft due to its buoyancy. A balloon travels by moving with the wind. It is distinct from an airship, which is a buoyant aircraft that can be propelled through the air in a controlled manner....

 was originally any aerostat, while the term airship
Airship
An airship or dirigible is a type of aerostat or "lighter-than-air aircraft" that can be steered and propelled through the air using rudders and propellers or other thrust mechanisms...

 was used for large, powered aircraft designs – usually fixed-wing – though none had yet been built. The advent of powered balloons, called dirigible balloons, and later of rigid hulls allowing a great increase in size, began to change the way these words were used. Huge powered aerostats, characterized by a rigid
Rigid airship
A rigid airship is a type of airship in which the envelope retained its shape by the use of an internal structural framework rather than by being forced into shape by the pressure of the lifting gas within the envelope as used in blimps and semi-rigid airships.Rigid airships were produced and...

 outer framework and separate aerodynamic skin surrounding the gas bags, were produced, the Zeppelin
Zeppelin
A Zeppelin is a type of rigid airship pioneered by the German Count Ferdinand von Zeppelin in the early 20th century. It was based on designs he had outlined in 1874 and detailed in 1893. His plans were reviewed by committee in 1894 and patented in the United States on 14 March 1899...

s being the largest and most famous. There were still no fixed-wing aircraft or non-rigid balloons large enough to be called airships, so "airship" came to be synonymous with these aircraft. Then several accidents, such as the Hindenburg disaster
Hindenburg disaster
The Hindenburg disaster took place on Thursday, May 6, 1937, as the German passenger airship LZ 129 Hindenburg caught fire and was destroyed during its attempt to dock with its mooring mast at the Lakehurst Naval Air Station, which is located adjacent to the borough of Lakehurst, New Jersey...

 in 1937, led to the demise of these airships. Nowadays a "balloon" is an unpowered aerostat, whilst an "airship" is a powered one.

A powered, steerable aerostat is called a dirigible. Sometimes this term is applied only to non-rigid balloons, and sometimes dirigible balloon is regarded as the definition of an airship (which may then be rigid or non-rigid). Non-rigid dirigibles are characterized by a moderately aerodynamic gasbag with stabilizing fins at the back. These soon became known as blimps
Non-rigid airship
A blimp, or non-rigid airship, is a floating airship without an internal supporting framework or keel. A non-rigid airship differs from a semi-rigid airship and a rigid airship in that it does not have any rigid structure, neither a complete framework nor a partial keel, to help the airbag...

. During the Second World War
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

, this shape was widely adopted for tethered balloons; in windy weather, this both reduces the strain on the tether and stabilizes the balloon. The nickname blimp was adopted along with the shape. In modern times, any small dirigible or airship is called a blimp, though a blimp may be unpowered as well as powered.

Heavier than air – aerodynes


Heavier-than-air aircraft must find some way to push air or gas downwards, so that a reaction occurs (by Newton's laws of motion) to push the aircraft upwards. This dynamic movement through the air is the origin of the term aerodyne. There are two ways to produce dynamic upthrust: aerodynamic lift
Aerodynamics
Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with...

, and powered lift
Powered lift
Powered lift or powered-lift refers to a type of aircraft that can take off and land vertically and functions differently from a rotorcraft in horizontal flight....

 in the form of engine thrust.

Aerodynamic lift involving wing
Wing
A wing is an appendage with a surface that produces lift for flight or propulsion through the atmosphere, or through another gaseous or liquid fluid...

s is the most common, with fixed-wing aircraft
Fixed-wing aircraft
A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...

 being kept in the air by the forward movement of wings, and rotorcraft
Rotorcraft
A rotorcraft or rotary wing aircraft is a heavier-than-air flying machine that uses lift generated by wings, called rotor blades, that revolve around a mast. Several rotor blades mounted to a single mast are referred to as a rotor. The International Civil Aviation Organization defines a rotorcraft...

 by spinning wing-shaped rotors sometimes called rotary wings. A wing is a flat, horizontal surface, usually shaped in cross-section as an aerofoil
Airfoil
An airfoil or aerofoil is the shape of a wing or blade or sail as seen in cross-section....

. To fly, air must flow over the wing and generate lift
Lift (force)
A fluid flowing past the surface of a body exerts a surface force on it. 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 surface force parallel to the flow direction...

. A flexible wing is a wing made of fabric or thin sheet material, often stretched over a rigid frame. A kite
Kite
A kite is a tethered aircraft. The necessary lift that makes the kite wing fly is generated when air flows over and under the kite's wing, producing low pressure above the wing and high pressure below it. This deflection also generates horizontal drag along the direction of the wind...

is tethered to the ground and relies on the speed of the wind over its wings, which may be flexible or rigid, fixed, or rotary.

With powered lift, the aircraft directs its engine thrust vertically
Vertical direction
In astronomy, geography, geometry and related sciences and contexts, a direction passing by a given point is said to be vertical if it is locally aligned with the gradient of the gravity field, i.e., with the direction of the gravitational force at that point...

 downward. V/STOL
V/STOL
Vertical and/or short take-off and landing is a term used to describe aircraft that are able to take-off or land vertically or on short runways. Vertical takeoff and landing describes craft which do not require runways at all...

 aircraft, such as the Harrier Jump Jet
Harrier Jump Jet
The Harrier, informally referred to as the Jump Jet, is a family of British-designed military jet aircraft capable of vertical/short takeoff and landing operations...

 and F-35B take off and land vertically using powered lift and transfer to aerodynamic lift in steady flight.

A pure rocket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

 is not usually regarded as an aerodyne, because it does not depend on the air for its lift (and can even fly into space); however, many aerodynamic lift vehicles have been powered or assisted by rocket motors. Rocket-powered missiles that obtain aerodynamic lift at very high speed due to airflow over their bodies are a marginal case.

Fixed-wing



Airplanes or aeroplanes are technically called fixed-wing aircraft
Fixed-wing aircraft
A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...

.

The forerunner of the fixed-wing aircraft is the kite
Kite
A kite is a tethered aircraft. The necessary lift that makes the kite wing fly is generated when air flows over and under the kite's wing, producing low pressure above the wing and high pressure below it. This deflection also generates horizontal drag along the direction of the wind...

. Whereas a fixed-wing aircraft relies on its forward speed to create airflow over the wings, a kite is tethered to the ground and relies on the wind
Wind
Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...

 blowing over its wings to provide lift. Kites were the first kind of aircraft to fly, and were invented in China
History of science and technology in China
The history of science and technology in China is both long and rich with many contributions to science and technology. In antiquity, independently of other civilizations, ancient Chinese philosophers made significant advances in science, technology, mathematics, and astronomy...

 around 500 BC. Much aerodynamic research was done with kites before test aircraft, wind tunnels, and computer modelling programs became available.

The first heavier-than-air craft capable of controlled free-flight were gliders. A glider
Glider aircraft
Glider aircraft are heavier-than-air craft that are supported in flight by the dynamic reaction of the air against their lifting surfaces, and whose free flight does not depend on an engine. Mostly these types of aircraft are intended for routine operation without engines, though engine failure can...

 designed by Cayley
George Cayley
Sir George Cayley, 6th Baronet was a prolific English engineer and one of the most important people in the history of aeronautics. Many consider him the first true scientific aerial investigator and the first person to understand the underlying principles and forces of flight...

 carried out the first true manned, controlled flight in 1853.

Besides the method of propulsion, fixed-wing aircraft are in general characterized by their wing configuration
Wing configuration
Fixed-wing aircraft, popularly called aeroplanes, airplanes or just planes may be built with many wing configurations.This page provides a breakdown of types, allowing a full description of any aircraft's wing configuration...

. The most important wing characteristics are:
  • Number of wings – Monoplane
    Monoplane
    A monoplane is a fixed-wing aircraft with one main set of wing surfaces, in contrast to a biplane or triplane. Since the late 1930s it has been the most common form for a fixed wing aircraft.-Types of monoplane:...

    , biplane
    Biplane
    A biplane is a fixed-wing aircraft with two superimposed main wings. The Wright brothers' Wright Flyer used a biplane design, as did most aircraft in the early years of aviation. While a biplane wing structure has a structural advantage, it produces more drag than a similar monoplane wing...

    , etc.
  • Wing support – Braced or cantilever, rigid, or flexible.
  • Wing planform – including aspect ratio
    Aspect ratio
    The aspect ratio of a shape is the ratio of its longer dimension to its shorter dimension. It may be applied to two characteristic dimensions of a three-dimensional shape, such as the ratio of the longest and shortest axis, or for symmetrical objects that are described by just two measurements,...

    , angle of sweep
    Swept wing
    A swept wing is a wing planform favored for high subsonic jet speeds first investigated by Germany during the Second World War. Since the introduction of the MiG-15 and North American F-86 which demonstrated a decisive superiority over the slower first generation of straight-wing jet fighters...

    , and any variations along the span (including the important class of delta wing
    Delta wing
    The delta wing is a wing planform in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta .-Delta-shaped stabilizers:...

    s).
  • Location of the horizontal stabilizer, if any.
  • Dihedral angle – positive, zero, or negative (anhedral).


A variable geometry
Variable geometry
Variable geometry may refer to:* Variable-geometry ways to alter the shape of an aircraft's wings in flight in order to alter their aerodynamic properties* Multi-speed Europe, a proposed strategy for European integration...

 aircraft can change its wing configuration during flight.

A flying wing
Flying wing
A flying wing is a tailless fixed-wing aircraft which has no definite fuselage, with most of the crew, payload and equipment being housed inside the main wing structure....

has no fuselage, though it may have small blisters or pods. The opposite of this is a lifting body
Lifting body
A lifting body is a fixed-wing aircraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage with little or no conventional wing...

, which has no wings, though it may have small stabilising and control surfaces.

Wing-in-ground-effect vehicles may be considered as fixed-wing aircraft. They "fly" effeiciently close to the surface of the ground or water, like conventional aircraft during takeoff. An example is the Russian ekranoplan (nicknamed the "Caspian Sea Monster"). Man-powered aircraft also rely on ground effect to remain airborne with a minimal pilot power, but this is only because they are so underpowered — in fact, the airframe is capable of flying higher.

Rotorcraft


Rotorcraft, or rotary-wing aircraft, use a spinning rotor with aerofoil section blades (a rotary wing) to provide lift. Types include helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

s, autogyro
Autogyro
An autogyro , also known as gyroplane, gyrocopter, or rotaplane, is a type of rotorcraft which uses an unpowered rotor in autorotation to develop lift, and an engine-powered propeller, similar to that of a fixed-wing aircraft, to provide thrust...

s, and various hybrids such as gyrodynes and compound rotorcraft.

Helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

s
have a rotor turned by an engine-driven shaft. The rotor pushes air downward to create lift. By tilting the rotor forward, the downward flow is tilted backward, producing thrust for forward flight. Some helicopters have more than one rotor and a few have rotors turned by gas jets at the tips.

Autogyro
Autogyro
An autogyro , also known as gyroplane, gyrocopter, or rotaplane, is a type of rotorcraft which uses an unpowered rotor in autorotation to develop lift, and an engine-powered propeller, similar to that of a fixed-wing aircraft, to provide thrust...

s
have unpowered rotors, with a separate power plant to provide thrust. The rotor is tilted backward. As the autogyro moves forward, air blows upward across the rotor, making it spin. This spinning increases the speed of airflow over the rotor, to provide lift. Rotor kite
Rotor kite
A rotor kite or gyroglider is an unpowered, rotary-wing aircraft. Like an autogyro or helicopter, it relies on lift created by one or more sets of rotors in order to fly...

s are unpowered autogyros, which are towed to give them forward speed or tethered to a static anchor in high-wind for kited flight.

Compound rotorcraft have wings that provide some or all of the lift in forward flight. They are nowadays classified as powered lift
Powered lift
Powered lift or powered-lift refers to a type of aircraft that can take off and land vertically and functions differently from a rotorcraft in horizontal flight....

types and not as rotorcraft. Tiltrotor
Tiltrotor
A tiltrotor is an aircraft which uses a pair or more of powered rotors mounted on rotating shafts or nacelles at the end of a fixed wing for lift and propulsion, and combines the vertical lift capability of a helicopter with the speed and range of a conventional fixed-wing aircraft...

aircraft (such as the V-22 Osprey
V-22 Osprey
The Bell Boeing V-22 Osprey is an American multi-mission, military, tiltrotor aircraft with both a vertical takeoff and landing , and short takeoff and landing capability...

), tiltwing
Tiltwing
A tiltwing aircraft features a wing that is horizontal for conventional forward flight and rotates up for vertical takeoff and landing. It is similar to the tiltrotor design where only the propeller and engine rotate. Tiltwing aircraft are typically fully capable of VTOL operations.The tiltwing...

, tailsitter
Tailsitter
A tailsitter is a type of VTOL aircraft that launches and lands on its tail. One of the most famous examples of this type of aircraft is the Ryan X-13 Vertijet. Among the propeller-driven versions were the Lockheed XFV, and the Convair XFY Pogo. Studies and wind tunnel models were made of a...

, and coleopter
Coleopter
A coleopter is a type of Vertical Take-Off and Landing aircraft design that uses a ducted fan as the primary fuselage of the entire aircraft. Generally they appear to be a large barrel-like extension at the rear, with a small cockpit area suspended above it. Like most ducted fan designs, coleopters...

 aircraft have their rotors/propellers
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...

 horizontal for vertical flight and vertical for forward flight.

Other methods of lift



  • A lifting body
    Lifting body
    A lifting body is a fixed-wing aircraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage with little or no conventional wing...

    is an aircraft body shaped to produce lift. If there are any wings, they are too small to provide significant lift and are used only for stability and control. Lifting bodies are not efficient: they suffer from high drag, and must also travel at high speed to generate enough lift to fly. Many of the research prototypes, such as the Martin-Marietta X-24, which led up to the Space Shuttle
    Space Shuttle
    The Space Shuttle was a manned orbital rocket and spacecraft system operated by NASA on 135 missions from 1981 to 2011. The system combined rocket launch, orbital spacecraft, and re-entry spaceplane with modular add-ons...

    , were lifting bodies (though the shuttle itself is not), and some supersonic
    Supersonic
    Supersonic speed is a rate of travel of an object that exceeds the speed of sound . For objects traveling in dry air of a temperature of 20 °C this speed is approximately 343 m/s, 1,125 ft/s, 768 mph or 1,235 km/h. Speeds greater than five times the speed of sound are often...

     missile
    Missile
    Though a missile may be any thrown or launched object, it colloquially almost always refers to a self-propelled guided weapon system.-Etymology:The word missile comes from the Latin verb mittere, meaning "to send"...

    s obtain lift from the airflow over a tubular body.
  • Powered lift
    Powered lift
    Powered lift or powered-lift refers to a type of aircraft that can take off and land vertically and functions differently from a rotorcraft in horizontal flight....

    types rely on engine-derived lift for vertical takeoff and landing (VTOL
    VTOL
    A vertical take-off and landing aircraft is one that can hover, take off and land vertically. This classification includes fixed-wing aircraft as well as helicopters and other aircraft with powered rotors, such as cyclogyros/cyclocopters and tiltrotors...

    ). Most types transition to fixed-wing lift for horizontal flight. Classes of powered lift types include VTOL
    VTOL
    A vertical take-off and landing aircraft is one that can hover, take off and land vertically. This classification includes fixed-wing aircraft as well as helicopters and other aircraft with powered rotors, such as cyclogyros/cyclocopters and tiltrotors...

     jet aircraft (such as the Harrier jump-jet) and tiltrotors (such as the V-22 Osprey
    V-22 Osprey
    The Bell Boeing V-22 Osprey is an American multi-mission, military, tiltrotor aircraft with both a vertical takeoff and landing , and short takeoff and landing capability...

    ), among others.

Unpowered



Gliders are heavier-than-air aircraft that do not employ propulsion once airborne. Take-off may be by launching forward and downward from a high location, or by pulling into the air on a tow-line, either by a ground-based winch or vehicle, or by a powered "tug" aircraft. For a glider to maintain its forward air speed and lift, it must descend in relation to the air (but not necessarily in relation to the ground). Many gliders can 'soar' - gain height from updrafts such as thermal currents. The first practical, controllable example was designed and built by the British scientist and pioneer George Cayley
George Cayley
Sir George Cayley, 6th Baronet was a prolific English engineer and one of the most important people in the history of aeronautics. Many consider him the first true scientific aerial investigator and the first person to understand the underlying principles and forces of flight...

, whom many recognise as the first aeronautical engineer. Common examples of gliders are sailplanes
Glider (sailplane)
A glider or sailplane is a type of glider aircraft used in the sport of gliding. Some gliders, known as motor gliders are used for gliding and soaring as well, but have engines which can, in some cases, be used for take-off or for extending a flight...

, hang gliders and paragliders.

Balloons
Balloon (aircraft)
A balloon is a type of aircraft that remains aloft due to its buoyancy. A balloon travels by moving with the wind. It is distinct from an airship, which is a buoyant aircraft that can be propelled through the air in a controlled manner....

 drift with the wind, though normally the pilot can control the altitude, either by heating the air or by releasing ballast, giving some directional control (since the wind direction changes with altitude). A wing-shaped hybrid balloon can glide directionally when rising or falling; but a spherically shaped balloon does not have such directional control.

Kite
Kite
A kite is a tethered aircraft. The necessary lift that makes the kite wing fly is generated when air flows over and under the kite's wing, producing low pressure above the wing and high pressure below it. This deflection also generates horizontal drag along the direction of the wind...

s are aircraft that are tethered to the ground or other object (fixed or mobile) that maintains tension in the tether or kite line
Kite line
Kites have a wing and a kite line , or sometimes more than one line. Kite systems may have more than one kite and more than one kite line....

; they rely on virtual or real wind blowing over and under them to generate lift and drag. Kytoon
Kytoon
A kytoon is a kite with a significant amount of aerostatic lift from a lighter than air gas carried within.The primary advantage of a kytoon is that it remains up and at a reasonably stable position above the tether point, irrespective of the wind.The kytoon has been used in peace and war...

s are balloon-kite hybrids that are shaped and tethered to obtain kiting deflections, and can be lighter-than-air, neutrally buoyant, or heavier-than-air.

Propeller aircraft




A propeller
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...

 or airscrew spins on an axis aligned in the direction of travel to create thrust in a forward direction. The propeller is usually mounted in front of the power source in tractor configuration
Tractor configuration
thumb|right|[[Evektor-Aerotechnik|Aerotechnik EV97A Eurostar]], a tractor configuration aircraft, being pulled into position by its pilot for refuelling....

but can be mounted behind in pusher configuration
Pusher configuration
In a craft with a pusher configuration the propeller are mounted behind their respective engine. According to Bill Gunston, a "pusher propeller" is one mounted behind engine so that drive shaft is in compression...

. Variations of propellers layout include contra-rotating propellers
Contra-rotating propellers
Aircraft equipped with contra-rotating propellers, also referred to as coaxial contra-rotating propellers, apply the maximum power of usually a single piston or turboprop engine to drive two propellers in contra-rotation...

and ducted fan
Ducted fan
A ducted fan is a propulsion arrangement whereby a fan, which is a type of propeller, is mounted within a cylindrical shroud or duct. The duct reduces losses in thrust from the tip vortices of the fan, and varying the cross-section of the duct allows the designer to advantageously affect the...

s
.

Many kinds of power plant have been used to drive propellers. Early airships used man power and steam-power
Steam aircraft
Steam aircraft are aircraft that are propelled by steam engines. They were unusual devices because of the difficulty in producing a powerplant with a high enough power-to-weight ratio to be practical...

. The more practical internal combustion piston engine
Internal combustion engine
The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine, the expansion of the high-temperature and high -pressure gases produced by combustion apply direct force to some component of the engine...

 was the power source used for virtually all fixed-wing aircraft until World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 and is still used in many smaller aircraft. Many larger aircraft use turbine engines to drive a propeller in the form of a turboprop
Turboprop
A turboprop engine is a type of turbine engine which drives an aircraft propeller using a reduction gear.The gas turbine is designed specifically for this application, with almost all of its output being used to drive the propeller...

 or propfan
Propfan
A propfan was first defined as a small diameter, highly loaded multiple bladed variable pitch propulsor having swept blades with thin advanced airfoil sections, integrated with a nacelle contoured to retard the airflow through the blades thereby reducing compressibility losses and designed to...

. Human-powered heavier-than-air flight has been achieved, but has not become a practical means of transport. Unmanned aircraft and models have also used other power sources such as solar-powered electric motors and rubber bands.

Jet aircraft




Airbreathing jet engine
Airbreathing jet engine
An airbreathing jet engine is a jet engine propelled by a jet of hot exhaust gases formed from air that is drawn into the engine via an inlet duct....

s take in air, burn fuel with it in a combustion chamber
Combustion chamber
A combustion chamber is the part of an engine in which fuel is burned.-Internal combustion engine:The hot gases produced by the combustion occupy a far greater volume than the original fuel, thus creating an increase in pressure within the limited volume of the chamber...

, and accelerate the exhaust rearwards at high speed to provide thrust. Turbojet and turbofan
Turbofan
The turbofan is a type of airbreathing jet engine that is widely used for aircraft propulsion. A turbofan combines two types of engines, the turbo portion which is a conventional gas turbine engine, and the fan, a propeller-like ducted fan...

 engines use a spinning turbine to drive one or more fans, which provide thrust. An afterburner
AfterBurner
The AfterBurner is a lighting solution for the Game Boy Advance system that was created by Triton-Labs.Originally, portablemonopoly.net was a website created to petition Nintendo to put some kind of light in their Game Boy Advance system...

 may be used to inject extra fuel into the hot exhaust, especially on military "fast jets".

Jet engines can provide much higher thrust than propellers, at higher speeds, and are at their most efficient at higher altitudes, being able to operate above 40000 ft (12,192 m), and there their fuel efficiency is about the same as the best piston and propeller engines. They are also much more fuel-efficient than rocket
Rocket
A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

s. As a consequence, nearly all public transport liners, high-speed and high-altitude aircraft, use jet engines.
Use of a turbine is not absolutely necessary: other designs include the pulse jet
Pulse jet engine
A pulse jet engine is a type of jet engine in which combustion occurs in pulses. Pulsejet engines can be made with few or no moving parts, and are capable of running statically....

 and ramjet
Ramjet
A ramjet, sometimes referred to as a stovepipe jet, or an athodyd, is a form of airbreathing jet engine using the engine's forward motion to compress incoming air, without a rotary compressor. Ramjets cannot produce thrust at zero airspeed and thus cannot move an aircraft from a standstill...

. These mechanically simple designs cannot work when stationary, so the aircraft must be launched to flying speed by some other method. Other variants have also been used, including the motorjet
Motorjet
A motorjet is a rudimentary type of jet engine which is sometimes referred to as thermojet, a term now commonly used to describe a particular and completely unrelated pulsejet design.- Design :...

 and hybrids such as the Pratt & Whitney J58
Pratt & Whitney J58
The Pratt & Whitney J58 was a jet engine used on the Lockheed A-12, and subsequently on the YF-12 and SR-71 Blackbird aircraft. The J58 was a variable cycle engine which functioned as both a turbojet and a fan-assisted ramjet. The J58 was a single-spool turbojet engine with an afterburner...

, which can convert between turbojet and ramjet operation.

Rotorcraft


A helicopter
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forwards, backwards, and laterally...

 obtains lift from a powered rotary wing or rotor, which acts much like an upward-pointing propeller. Forward propulsion is provided by angling the rotor disc slightly forward so that a proportion of its lift is directed forward to provide thrust. The rotor may, like a propeller, be powered by a variety of methods such as a piston engine or turbine. Experiments have also used jet nozzles at rotor blade tips.

Other methods of propulsion

  • Rocket-powered aircraft
    Rocket-powered aircraft
    A rocket-powered aircraft or rocket plane is an aircraft that uses a rocket for propulsion, sometimes in addition to airbreathing jet engines. Rocket planes can achieve much higher speeds than similarly sized jet aircraft, but typically for at most a few minutes of powered operation, followed by a...

    have occasionally been experimented with, and the Messerschmitt Komet
    Messerschmitt Me 163
    The Messerschmitt Me 163 Komet, designed by Alexander Lippisch, was a German rocket-powered fighter aircraft. It is the only rocket-powered fighter aircraft ever to have been operational. Its design was revolutionary, and the Me 163 was capable of performance unrivaled at the time. Messerschmitt...

     fighter even saw action in the Second World War. Since then, they have been restricted to research aircraft, such as the North American X-15
    North American X-15
    The North American X-15 rocket-powered aircraft/spaceplane was part of the X-series of experimental aircraft, initiated with the Bell X-1, that were made for the USAAF/USAF, NACA/NASA, and the USN. The X-15 set speed and altitude records in the early 1960s, reaching the edge of outer space and...

    , which traveled up into space where air-breathing engines cannot work (rockets carry their own oxidant). Rockets have more often been used as a supplement to the main powerplant, typically for the rocket-assisted take off of heavily loaded aircraft, but also to provide high-speed dash capability in some hybrid designs such as the Saunders-Roe SR.53
    Saunders-Roe SR.53
    |- See also :-References:NotesBibliography* Jones, Barry. "Saro's Mixed Power Saga". Aeroplane Monthly, November 1994, Vol 22 No 11 Issue 259. pp. 32–39. London:IPC. ISSN 0143-7240....

    .
  • The ornithopter
    Ornithopter
    An ornithopter is an aircraft that flies by flapping its wings. Designers seek to imitate the flapping-wing flight of birds, bats, and insects. Though machines may differ in form, they are usually built on the same scale as these flying creatures. Manned ornithopters have also been built, and some...

    obtains thrust by flapping its wings. It has found practical use in a model hawk used to freeze prey animals into stillness so that they can be captured, and in toy birds.

General construction


The parts of an aircraft are generally divided into three categories:
  • The airframe comprises the mechanical structure and associated equipment.
  • The propulsion system comprises the engine or engines and associated equipment.
  • The avionics comprise the electrical flight control and communication systems.

Airframe




The airframe of an aircraft is its mechanical structure, which is typically considered to exclude the propulsion system
Air propulsion
Air propulsion is the generation of thrust during flight by an aircraft or a creature such as a bird, bat or insect.-Aircraft:An aircraft propulsion system must serve two purposes. First, the thrust from the propulsion system must balance the drag of the airplane when the airplane is cruising...

. Airframe design is a field of engineering
Engineering
Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...

 that combines aerodynamics
Aerodynamics
Aerodynamics is a branch of dynamics concerned with studying the motion of air, particularly when it interacts with a moving object. Aerodynamics is a subfield of fluid dynamics and gas dynamics, with much theory shared between them. Aerodynamics is often used synonymously with gas dynamics, with...

, materials technology
Materials science
Materials science is an interdisciplinary field applying the properties of matter to various areas of science and engineering. This scientific field investigates the relationship between the structure of materials at atomic or molecular scales and their macroscopic properties. It incorporates...

, and manufacturing
Manufacturing
Manufacturing is the use of machines, tools and labor to produce goods for use or sale. The term may refer to a range of human activity, from handicraft to high tech, but is most commonly applied to industrial production, in which raw materials are transformed into finished goods on a large scale...

 methods to achieve balances of performance, reliability
Reliability engineering
Reliability engineering is an engineering field, that deals with the study, evaluation, and life-cycle management of reliability: the ability of a system or component to perform its required functions under stated conditions for a specified period of time. It is often measured as a probability of...

, and cost.

The main parts of the airframe are the fuselage, wing and tail.

Fuselage



The fuselage
Fuselage
The fuselage is an aircraft's main body section that holds crew and passengers or cargo. In single-engine aircraft it will usually contain an engine, although in some amphibious aircraft the single engine is mounted on a pylon attached to the fuselage which in turn is used as a floating hull...

 is an aircraft's main body section containing the crew cockpit
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...

 or flight deck, and any passenger cabin
Aircraft cabin
An aircraft cabin is the section of an aircraft in which passengers travel. At cruising altitudes of modern commercial aircraft the surrounding atmosphere is too thin to breathe without an oxygen mask, so cabins are pressurized at a higher pressure than ambient pressure at altitude.In commercial...

 or cargo
Cargo
Cargo is goods or produce transported, generally for commercial gain, by ship, aircraft, train, van or truck. In modern times, containers are used in most intermodal long-haul cargo transport.-Marine:...

 hold. In single- and twin-engine aircraft, it will often also contain the engine or engines. The fuselage also serves to position control and stabilization surfaces in specific relationships to lifting surfaces, required for aircraft stability and maneuverability.

Wing


The wing
Wing
A wing is an appendage with a surface that produces lift for flight or propulsion through the atmosphere, or through another gaseous or liquid fluid...

s of an aircraft produce lift. Many different styles and arrangements of wings
Wing configuration
Fixed-wing aircraft, popularly called aeroplanes, airplanes or just planes may be built with many wing configurations.This page provides a breakdown of types, allowing a full description of any aircraft's wing configuration...

 have been used on heavier-than-air aircraft, and some lighter-than-air craft also have wings. Most early fixed-wing aircraft were biplane
Biplane
A biplane is a fixed-wing aircraft with two superimposed main wings. The Wright brothers' Wright Flyer used a biplane design, as did most aircraft in the early years of aviation. While a biplane wing structure has a structural advantage, it produces more drag than a similar monoplane wing...

s, having wings stacked one above the other. Most types nowadays are monoplane
Monoplane
A monoplane is a fixed-wing aircraft with one main set of wing surfaces, in contrast to a biplane or triplane. Since the late 1930s it has been the most common form for a fixed wing aircraft.-Types of monoplane:...

s, having one wing each side. Wings also vary greatly in their shape viewed from above
Planform
In aviation, a planform is the shape and layout of a fixed-wing aircraft's fuselage and wing. Of all the myriad planforms used, they can typically be grouped into those used for low-speed flight, found on general aviation aircraft, and those used for high-speed flight, found on many military...

.

Control surfaces


Flight control surfaces allow a pilot to control an aircraft's flight attitude.

Development of an effective set of flight controls was a critical advance in the development of aircraft. Early efforts at fixed-wing aircraft design succeeded in generating sufficient lift to get the aircraft off the ground, but, once aloft, the aircraft proved uncontrollable, often with disastrous results. The development of effective flight controls is what allowed flight.

Horizontal and vertical stabilizers


In spite of effective control surfaces, many early aircraft were virtually unflyable.

The horizontal and vertical stabilizers
Stabilizer (aircraft)
In aviation, a stabilizer provides stability when the aircraft is flying straight, and the airfoil of the horizontal stabilizer balances the forces acting on the aircraft....

 of most aircraft give stability, in a similar way to the feathers on an arrow. Most aircraft feature empennage
Empennage
The empennage , also known as the tail or tail assembly, of most aircraft gives stability to the aircraft, in a similar way to the feathers on an arrow...

 (a tail section) incorporating vertical, and horizontal stabilizing surfaces which allow equilibrium of aerodynamic forces, stabilize the flight dynamics
Flight dynamics
Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions about the vehicle's center of mass, known as pitch, roll and yaw .Aerospace engineers develop control systems for...

 of pitch and yaw, as well as housing control surfaces.

Today, only a few (often relatively less stable) heavier than air aircraft are able to fly 'tailless
Tailless aircraft
A tailless aircraft traditionally has all its horizontal control surfaces on its main wing surface. It has no horizontal stabilizer - either tailplane or canard foreplane . A 'tailless' type usually still has a vertical stabilising fin and control surface...

' without specific horizontal stabilizers.

Undercarriage


The undercarriage
Undercarriage
The undercarriage or landing gear in aviation, is the structure that supports an aircraft on the ground and allows it to taxi, takeoff and land...

 or landing gear, is the structure that supports an aircraft on the ground and allows it to taxi
Taxiing
Taxiing refers to the movement of an aircraft on the ground, under its own power, in contrast to towing or push-back where the aircraft is moved by a tug...

, take off, and land. In the typical undercarriage, wheels are used, but skids, floats, or a combination of these and other elements can be used, depending on the surface. Many aircraft have undercarriage that retracts into the wings and/or fuselage to decrease drag during flight.

Flying boat
Flying boat
A flying boat is a fixed-winged seaplane with a hull, allowing it to land on water. It differs from a float plane as it uses a purpose-designed fuselage which can float, granting the aircraft buoyancy. Flying boats may be stabilized by under-wing floats or by wing-like projections from the fuselage...

s are supported on water by their fuselage and hence have no undercarriage, except for amphibians
Amphibious aircraft
An amphibious aircraft or amphibian is an aircraft that can take off and land on either land or water. Fixed-wing amphibious aircraft are seaplanes that are equipped with retractable wheels, at the expense of extra weight and complexity, plus diminished range and fuel economy compared to planes...

, which have retractable undercarriage allowing them to take off from and alight on both land and water.

Other


Other structural and aerodynamic components are often present, canard
Canard (aeronautics)
In aeronautics, canard is an airframe configuration of fixed-wing aircraft in which the forward surface is smaller than the rearward, the former being known as the "canard", while the latter is the main wing...

s are wings situated near the nose of the vehicle, notably on fighter jets. Booms and other unusual components such as external drop tank
Drop tank
In aeronautics, a drop tank is used to describe auxiliary fuel tanks externally carried by aircraft. A drop tank is expendable and often jettisonable...

s.

Engines



Powered aircraft have one or more engines. Most aircraft engines are either lightweight piston engines or gas turbine
Gas turbine
A gas turbine, also called a combustion turbine, is a type of internal combustion engine. It has an upstream rotating compressor coupled to a downstream turbine, and a combustion chamber in-between....

s. The fuel is usually kept in tanks around the vehicle. Most aircraft store the fuel predominantly in the wings, but may have additional fuel tank
Fuel tank
A fuel tank is safe container for flammable fluids. Though any storage tank for fuel may be so called, the term is typically applied to part of an engine system in which the fuel is stored and propelled or released into an engine...

s elsewhere.

Avionics



The avionics comprise the flight control systems and other electronic equipment, including the cockpit
Cockpit
A cockpit or flight deck is the area, usually near the front of an aircraft, from which a pilot controls the aircraft. Most modern cockpits are enclosed, except on some small aircraft, and cockpits on large airliners are also physically separated from the cabin...

 instrumentation, radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

, and communication systems.

Flight envelope



The flight envelope of an aircraft refers to its capabilities in terms of airspeed
Airspeed
Airspeed is the speed of an aircraft relative to the air. Among the common conventions for qualifying airspeed are: indicated airspeed , calibrated airspeed , true airspeed , equivalent airspeed and density airspeed....

 and load factor or altitude. The term can also refer to other measurements such as maneuverability. When a plane is pushed, for instance by diving it at high speeds, it is said to be flown "outside the envelope", something considered unsafe.

Range


The maximal total range is the distance an aircraft can fly between takeoff
Takeoff
Takeoff is the phase of flight in which an aerospace vehicle goes from the ground to flying in the air.For horizontal takeoff aircraft this usually involves starting with a transition from moving along the ground on a runway. For balloons, helicopters and some specialized fixed-wing aircraft , no...

 and landing
Landing
thumb|A [[Mute Swan]] alighting. Note the ruffled feathers on top of the wings indicate that the swan is flying at the [[Stall |stall]]ing speed...

, as limited by fuel capacity in powered aircraft, or cross-country speed and environmental conditions in unpowered aircraft. The range can be seen as the cross-country ground speed multiplied by the maximum time in the air.

Ferry range means the maximum range an aircraft can fly. This usually means maximum fuel load, optionally with extra fuel tanks and minimum equipment. It refers to transport of aircraft for use on remote location.

The combat range is the maximum range an aircraft can fly when carrying ordnance. The combat radius
Combat radius
Combat radius refers to the distance from an airbase that a warplane can reach, patrol there for a set amount of time and return to base with minimal fuel left, thus completing a combat mission...

 is somewhat less.

The fuel time limit for powered aircraft is fixed by the fuel load and rate of consumption. For unpowered aircraft, the maximum flight time is limited by available daylight hours, weather conditions, and pilot endurance.

Flight dynamics




Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the angles of rotation in three dimensions
Dimensions
Dimensions is a French project that makes educational movies about mathematics, focusing on spatial geometry. It uses POV-Ray to render some of the animations, and the films are release under a Creative Commons licence....

 about the vehicle's center of mass
Center of mass
In physics, the center of mass or barycenter of a system is the average location of all of its mass. In the case of a rigid body, the position of the center of mass is fixed in relation to the body...

, known as pitch, roll, and yaw (quite different from their use as Tait-Bryan angles).
  • Roll is a rotation about the longitudinal axis (equivalent to the rolling or heeling of a ship) giving an up-down movement of the wing tips measured by the roll or bank angle.

  • Pitch is a rotation about the sideways horizontal axis giving an up-down movement of the aircraft nose measured by the angle of attack
    Angle of attack
    Angle of attack is a term used in fluid dynamics to describe the angle between a reference line on a lifting body and the vector representing the relative motion between the lifting body and the fluid through which it is moving...

    .

  • Yaw is a rotation about the vertical axis giving a side-to-side movement of the nose known as sideslip.


A fixed-wing aircraft
Fixed-wing aircraft
A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...

 increases or decreases the lift generated by the wings when it pitches, respectively, nose up or down by increasing or decreasing the angle of attack. A fixed-wing aircraft usually "banks" to change the horizontal direction of flight. To maintain direction, efficiency, and controllability of flight the sideslip angle must remain near zero, though there are instances when an aircraft may be deliberately "sideslipped," for example, a slip
Slip (aerodynamic)
A slip is an aerodynamic state where an aircraft is moving somewhat sideways as well as forward relative to the oncoming airflow. In other words, for a conventional aircraft, the nose will not be pointing directly into the relative wind .A slip is also a piloting maneuver where the pilot...

 in a fixed-wing aircraft.

Besides lift, the other main aerodynamic force on an aircraft is drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...

 opposing its motion through the air. An aircraft is usually streamlined from nose to tail to reduce drag.

Flight control
Aerospace engineers develop control system
Control system
A control system is a device, or set of devices to manage, command, direct or regulate the behavior of other devices or system.There are two common classes of control systems, with many variations and combinations: logic or sequential controls, and feedback or linear controls...

s for a vehicle's orientation (attitude) about its center of mass
Center of mass
In physics, the center of mass or barycenter of a system is the average location of all of its mass. In the case of a rigid body, the position of the center of mass is fixed in relation to the body...

. The control systems include actuators, which exert forces in various directions, and generate rotational forces or moment
Moment (physics)
In physics, the term moment can refer to many different concepts:*Moment of force is the tendency of a force to twist or rotate an object; see the article torque for details. This is an important, basic concept in engineering and physics. A moment is valued mathematically as the product of the...

s about the aerodynamic center
Aerodynamic center
The torques or moments acting on an airfoil moving through a fluid can be accounted for by the net lift applied at some point on the foil, and a separate net pitching moment about that point whose magnitude varies with the choice of where the lift is chosen to be applied...

 of the aircraft, and thus rotate the aircraft in pitch, roll, or yaw. For example, a pitching moment
Pitching moment
In aerodynamics, the pitching moment on an airfoil is the moment produced by the aerodynamic force on the airfoil if that aerodynamic force is considered to be applied, not at the center of pressure, but at the aerodynamic center of the airfoil...

 is a vertical force applied at a distance forward or aft from the aerodynamic center of the aircraft, causing the aircraft to pitch up or down. Control systems are also sometimes used to increase or decrease drag, for example to slow the aircraft to a safe speed for landing.

Areas of use


The major distinction in aircraft types is between military aircraft
Military aircraft
A military aircraft is any fixed-wing or rotary-wing aircraft that is operated by a legal or insurrectionary armed service of any type. Military aircraft can be either combat or non-combat:...

, which includes not just combat types but many types of supporting aircraft, and civil aircraft
Civil aviation
Civil aviation is one of two major categories of flying, representing all non-military aviation, both private and commercial. Most of the countries in the world are members of the International Civil Aviation Organization and work together to establish common standards and recommended practices...

, which include all non-military types.

Military




A military aircraft is any fixed-wing
Fixed-wing aircraft
A fixed-wing aircraft is an aircraft capable of flight using wings that generate lift due to the vehicle's forward airspeed. Fixed-wing aircraft are distinct from rotary-wing aircraft in which wings rotate about a fixed mast and ornithopters in which lift is generated by flapping wings.A powered...

 or rotary-wing
Rotorcraft
A rotorcraft or rotary wing aircraft is a heavier-than-air flying machine that uses lift generated by wings, called rotor blades, that revolve around a mast. Several rotor blades mounted to a single mast are referred to as a rotor. The International Civil Aviation Organization defines a rotorcraft...

 aircraft that is operated by a legal or insurrectionary armed service of any type. Military aircraft can be either combat or non-combat:
  • Combat aircraft are aircraft designed to destroy enemy equipment using its own armament. Combat aircraft divide broadly into fighters
    Fighter aircraft
    A fighter aircraft is a military aircraft designed primarily for air-to-air combat with other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets...

     and bomber
    Bomber
    A bomber is a military aircraft designed to attack ground and sea targets, by dropping bombs on them, or – in recent years – by launching cruise missiles at them.-Classifications of bombers:...

    s, with several in-between types such as fighter-bomber
    Fighter-bomber
    A fighter-bomber is a fixed-wing aircraft with an intended primary role of light tactical bombing and also incorporating certain performance characteristics of a fighter aircraft. This term, although still used, has less significance since the introduction of rockets and guided missiles into aerial...

    s and ground-attack aircraft (including attack helicopter
    Attack helicopter
    An attack helicopter is a military helicopter with the primary role of an attack aircraft, with the capability of engaging targets on the ground, such as enemy infantry and armored vehicles...

    s).
  • Non-Combat aircraft are not designed for combat as their primary function, but may carry weapons for self-defense. Non-combat roles include search and rescue, reconnaissance, observation, transport, training, and aerial refueling
    Aerial refueling
    Aerial refueling, also called air refueling, in-flight refueling , air-to-air refueling or tanking, is the process of transferring fuel from one aircraft to another during flight....

    . These aircraft are often variants of civil aircraft such as the Douglas DC-3
    Douglas DC-3
    The Douglas DC-3 is an American fixed-wing propeller-driven aircraft whose speed and range revolutionized air transport in the 1930s and 1940s. Its lasting impact on the airline industry and World War II makes it one of the most significant transport aircraft ever made...

     airliner.


Glider
Military glider
Military gliders have been used by the military of various countries for carrying troops and heavy equipment to a combat zone, mainly during the Second World War. These engineless aircraft were towed into the air and most of the way to their target by military transport planes, e.g...

s and balloon
Balloon
A balloon is an inflatable flexible bag filled with a gas, such as helium, hydrogen, nitrous oxide, oxygen, or air. Modern balloons can be made from materials such as rubber, latex, polychloroprene, or a nylon fabric, while some early balloons were made of dried animal bladders, such as the pig...

s have also been used as military aircraft; for example, balloons were used for observation during the American Civil War
American Civil War
The American Civil War was a civil war fought in the United States of America. In response to the election of Abraham Lincoln as President of the United States, 11 southern slave states declared their secession from the United States and formed the Confederate States of America ; the other 25...

 and World War I
World War I
World War I , which was predominantly called the World War or the Great War from its occurrence until 1939, and the First World War or World War I thereafter, was a major war centred in Europe that began on 28 July 1914 and lasted until 11 November 1918...

, and military glider
Military glider
Military gliders have been used by the military of various countries for carrying troops and heavy equipment to a combat zone, mainly during the Second World War. These engineless aircraft were towed into the air and most of the way to their target by military transport planes, e.g...

s were used during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...

 to land troops.

Civil


Civil aircraft divide into commercial and general types, however there are some overlaps.

Commercial aircraft
Commercial aviation
Commercial aviation is the part of civil aviation that involves operating aircraft for hire to transport passengers or cargo...

 include types designed for scheduled and charter airline flights, carrying both passengers and cargo
Cargo
Cargo is goods or produce transported, generally for commercial gain, by ship, aircraft, train, van or truck. In modern times, containers are used in most intermodal long-haul cargo transport.-Marine:...

. The larger passenger-carrying types are often referred to as airliners, the largest of which are wide-body aircraft
Wide-body aircraft
A wide-body aircraft is a large airliner with two passenger aisles, also known as a widebody aircraft or twin-aisle aircraft. The typical fuselage diameter is . In the typical wide-body economy cabin, passengers are seated seven to ten abreast, allowing a total capacity of 200 to 850 passengers...

. Some of the smaller types are also used in general aviation
General aviation
General aviation is one of the two categories of civil aviation. It refers to all flights other than military and scheduled airline and regular cargo flights, both private and commercial. General aviation flights range from gliders and powered parachutes to large, non-scheduled cargo jet flights...

, and some of the larger types are used as VIP aircraft.

General aviation
General aviation
General aviation is one of the two categories of civil aviation. It refers to all flights other than military and scheduled airline and regular cargo flights, both private and commercial. General aviation flights range from gliders and powered parachutes to large, non-scheduled cargo jet flights...

 is a catch-all covering other kinds of private
Private aviation
Private aviation is the part of civil aviation that does not include flying for hire. In most countries, private flights are always general aviation flights, but the opposite is not true: many general aviation flights are commercial in that the pilot is hired and paid...

 (where the pilot is not paid for time or expenses) and commercial use, and involving a wide range of aircraft types such as business jets (bizjets)
Business jet
Business jet, private jet or, colloquially, bizjet is a term describing a jet aircraft, usually of smaller size, designed for transporting groups of up to 19 business people or wealthy individuals...

, trainers
Trainer (aircraft)
A trainer is a class of aircraft designed specifically to facilitate in-flight training of pilots and aircrews. The use of a dedicated trainer aircraft with additional safety features—such as tandem flight controls, forgiving flight characteristics and a simplified cockpit arrangement—allows...

, homebuilt
Homebuilt aircraft
Also known as amateur-built aircraft or kit planes, homebuilt aircraft are constructed by persons for whom this is not a professional activity. These aircraft may be constructed from "scratch," from plans, or from assembly kits.-Overview:...

, aerobatic types
Aerobatics
Aerobatics is the practice of flying maneuvers involving aircraft attitudes that are not used in normal flight. Aerobatics are performed in airplanes and gliders for training, recreation, entertainment and sport...

, racers
Air racing
- History :The first ever air race was held in St. Louis, Missouri, in 1908. The participants piloted the only 4 airships in the U.S. around a course located at Forest Park...

, gliders
Glider (sailplane)
A glider or sailplane is a type of glider aircraft used in the sport of gliding. Some gliders, known as motor gliders are used for gliding and soaring as well, but have engines which can, in some cases, be used for take-off or for extending a flight...

, warbird
Warbird
Warbird is a term used, predominantly in North America, to describe vintage military aircraft.- Naming :Although the term originally implied piston-driven aircraft from the World War II era, it is now often extended to include all military aircraft, including jet-powered aircraft, that are no...

s, firefighters
Aerial firefighting
Aerial firefighting is the use of aircraft and other aerial resources to combat wildfires. The types of aircraft used include fixed-wing aircraft and helicopters. Smokejumpers and rappellers are also classified as aerial firefighters, delivered to the fire by parachute from a variety of fixed-wing...

, medical transports
MEDEVAC
Medical evacuation, often termed Medevac or Medivac, is the timely and efficient movement and en route care provided by medical personnel to the wounded being evacuated from the battlefield or to injured patients being evacuated from the scene of an accident to receiving medical facilities using...

, and cargo
Cargo aircraft
A cargo aircraft is a fixed-wing aircraft designed or converted for the carriage of goods, rather than passengers. They are usually devoid of passenger amenities, and generally feature one or more large doors for the loading and unloading of cargo...

 transports, to name a few. The vast majority of aircraft today are general aviation types.

Experimental



Experimental aircraft are one-off specials, built to explore some aspect of aircraft design and with no other useful purpose. The Bell X-1
Bell X-1
The Bell X-1, originally designated XS-1, was a joint NACA-U.S. Army/US Air Force supersonic research project built by Bell Aircraft. Conceived in 1944 and designed and built over 1945, it eventually reached nearly 1,000 mph in 1948...

 rocket plane, which first broke the sound barrier in level flight, is a famous example.

Model



A model aircraft is a small unmanned type made to fly for fun, for static display, for aerodynamic research or for other purposes. A scale model
Scale model
A scale model is a physical model, a representation or copy of an object that is larger or smaller than the actual size of the object, which seeks to maintain the relative proportions of the physical size of the original object. Very often the scale model is used as a guide to making the object in...

 is a replica of some larger design.

Lists



Topics

  • Air safety
    Air safety
    Air safety is a term encompassing the theory, investigation and categorization of flight failures, and the prevention of such failures through regulation, education and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel.-United...

  • Airmail
    Airmail
    Airmail is mail that is transported by aircraft. It typically arrives more quickly than surface mail, and usually costs more to send...

  • Aircraft design process
    Aircraft design process
    The term Aircraft design can have many different meanings:*An aircraft design as defined by type definition documentation, such as a type certificate for certified aircraft and as legally defined by the appropriate Airworthiness certificate, including a Standard Airworthiness Certificate for...

  • Aircraft axis
    Aircraft axis
    An aircraft in flight is free to rotate in three dimensions: pitch, nose up or down about an axis running from wing to wing), yaw, nose left or right about an axis running up and down; and roll, rotation about an axis running from nose to tail. The axes are alternatively designated as lateral,...

  • Aircraft recycling
  • Aircraft spotting
    Aircraft spotting
    Aircraft spotting or plane spotting is the observation and logging of the registration numbers of aircraft: gliders, powered aircraft, balloons, airships, helicopters, and microlights....

  • Airliner
    Airliner
    An airliner is a large fixed-wing aircraft for transporting passengers and cargo. Such aircraft are operated by airlines. Although the definition of an airliner can vary from country to country, an airliner is typically defined as an aircraft intended for carrying multiple passengers in commercial...

  • Aviation
    Aviation
    Aviation is the design, development, production, operation, and use of aircraft, especially heavier-than-air aircraft. Aviation is derived from avis, the Latin word for bird.-History:...

 
  • Contrail
    Contrail
    Contrails or vapour trails are artificial clouds that are the visible trails of condensed water vapour made by the exhaust of aircraft engines...

  • First flying machine
    First flying machine
    There are conflicting views as to what was the first flying machine.Much of the debate surrounding records of early flying machines depends on the exact definition of what constitutes a "flying machine", "flight", and even "first"....

  • Flight controls
    Aircraft flight control systems
    A conventional fixed-wing aircraft flight control system consists of flight control surfaces, the respective cockpit controls, connecting linkages, and the necessary operating mechanisms to control an aircraft's direction in flight...

  • Flight instruments
    Flight instruments
    Flight instruments are the instruments in the cockpit of an aircraft that provide the pilot with information about the flight situation of that aircraft, such as height, speed and altitude...

  • Flying car/roadable aircraft
  • Military aircraft
    Military aircraft
    A military aircraft is any fixed-wing or rotary-wing aircraft that is operated by a legal or insurrectionary armed service of any type. Military aircraft can be either combat or non-combat:...

  • Aircraft noise
    Aircraft noise
    Aircraft noise is noise pollution produced by any aircraft or its components, during various phases of a flight: on the ground while parked such as auxiliary power units, while taxiing, on run-up from propeller and jet exhaust, during take off, underneath and lateral to departure and arrival paths,...

  •  
  • Personal air vehicle
    Personal air vehicle
    A personal air vehicle or PAV, also personal aerial vehicle, is a class of light general aviation aircraft which meets design and performance goals intended to make flying as commonplace as driving...

  • Powered parachute
    Powered parachute
    A powered parachute is a parachute with motor and wheels. The aircraft's airspeed is typically about 25–35 mph . PPCs operate safely at heights ranging from a few feet off the ground to altitudes as high as 18,000+ feet...

  • Rocket
    Rocket
    A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. Rocket engines work by action and reaction...

  • Spacecraft
    Spacecraft
    A spacecraft or spaceship is a craft or machine designed for spaceflight. Spacecraft are used for a variety of purposes, including communications, earth observation, meteorology, navigation, planetary exploration and transportation of humans and cargo....

  • Spaceplane
    Spaceplane
    A spaceplane is a vehicle that operates as an aircraft in Earth's atmosphere, as well as a spacecraft when it is in space. It combines features of an aircraft and a spacecraft, which can be thought of as an aircraft that can endure and maneuver in the vacuum of space or likewise a spacecraft that...

  • Steam aircraft
    Steam aircraft
    Steam aircraft are aircraft that are propelled by steam engines. They were unusual devices because of the difficulty in producing a powerplant with a high enough power-to-weight ratio to be practical...

  • Wide-body aircraft
    Wide-body aircraft
    A wide-body aircraft is a large airliner with two passenger aisles, also known as a widebody aircraft or twin-aisle aircraft. The typical fuselage diameter is . In the typical wide-body economy cabin, passengers are seated seven to ten abreast, allowing a total capacity of 200 to 850 passengers...


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    History

    Information