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{{redirect|Aeroplane||Airplane (disambiguation)|and|Aeroplane (disambiguation)}}
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[[File:P-51 Mustang edit1.jpg|thumb|300px|[[North American P-51 Mustang]], a [[World War II]] fighter]]
[[File:First flight2.jpg|thumb|300px|The first flight of an airplane, the [[Wright Flyer]] on December 17, 1903]]

An '''airplane''' or '''aeroplane'''{{ref|Alpha|A}} (informally '''plane''') is a [[Motive power|powered]], [[fixed-wing aircraft]] that is propelled forward by [[thrust]] from a [[jet engine]] or [[Propeller (aircraft)|propeller]]. Airplanes come in a variety of sizes, shapes, and [[wing configuration]]s. The broad spectrum of uses for airplanes includes [[recreation]], [[air transportation|transportation]] of goods and people, [[military aviation|military]], and research. [[Commercial aviation]] is a massive industry involving the flying of tens of thousands of passengers daily on [[airliners]]. Most airplanes are flown by a [[aviator|pilot]] on board the aircraft, but some are designed to be [[unmanned aerial vehicle|remotely or computer-controlled]].

The [[Wright brothers]] invented and flew the first airplane in 1903, recognized as "the first sustained and controlled heavier-than-air powered flight".<ref name="auto1">[http://www.fai.org/news_archives/fai/000295.asp FAI News: 100 Years Ago, the Dream of Icarus Became Reality] posted 17 December 2003. Retrieved: 5 January 2007.</ref> They built on the works of [[George Cayley]] dating from 1799, when he set forth the concept of the modern airplane (and later built and flew models and successful passenger-carrying [[Glider aircraft|glider]]s).<ref name="auto">[http://www.britannica.com/eb/article-9360092 "Cayley, Sir George: Encyclopædia Britannica 2007."] ''Encyclopædia Britannica Online'', 25 August 2007.</ref> Between 1867 and 1896, the German pioneer of human aviation [[Otto Lilienthal]] also studied heavier-than-air flight. Following its limited use in [[Aviation in World War I|World War I]], aircraft technology continued to develop. Airplanes had a presence in all the major battles of [[World War II]]. The first [[jet aircraft]] was the German [[Heinkel He 178]] in 1939. The first [[jet airliner]], the [[de Havilland Comet]], was introduced in 1952. The [[Boeing 707]], the first widely successful commercial jet, was in commercial service for more than 50 years, from 1958 to at least 2013.

==Etymology and usage==
First attested in [[English language|English]] in the late 19th century (prior to the first sustained powered flight), the word ''airplane'', like ''aeroplane'', derives from the [[French (language)|French]] ''aéroplane'', which comes from the [[Ancient Greek|Greek]] ἀήρ (''aēr''), "air"<ref>[http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Da%29h%2Fr ἀήρ], Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus</ref> and either [[Latin]] ''planus'', "level",<ref>[http://www.merriam-webster.com/dictionary/aeroplane "aeroplane"], Merriam-Webster Online Dictionary.</ref> or Greek πλάνος (''planos''), "wandering".<ref>[http://www.perseus.tufts.edu/hopper/text?doc=Perseus%3Atext%3A1999.04.0057%3Aentry%3Dpla%2Fnos πλάνος], Henry George Liddell, Robert Scott, ''A Greek-English Lexicon'', on Perseus</ref><ref>[http://oxforddictionaries.com/view/entry/m_en_gb0011110#m_en_gb0011110 aeroplane], Oxford Dictionaries</ref> "''Aéroplane''" originally referred just to the wing, as it is a [[plane (geometry)|plane]] moving through the [[air]].<ref>[http://www.oed.com/view/Entry/3196#eid9528640 "aeroplane], Oxford English Dictionary online.</ref> In an example of [[synecdoche]], the word for the wing came to refer to the entire aircraft.

In the [[United States]] and [[Canada]], the term "airplane" is used for powered fixed-wing aircraft. In the [[United Kingdom]] and most of the [[Commonwealth of Nations|Commonwealth]], the term "aeroplane" is usually applied to these aircraft.

==History==
{{Main|Aviation history|First flying machine}}
[[File:LeBris1868.jpg|thumb|[[Jean-Marie Le Bris|Le Bris]] and his [[glider aircraft|glider]], Albatros II, photographed by [[Nadar (photographer)|Nadar]], 1868]]
[[File:Otto Lilienthal gliding experiment ppmsca.02546.jpg|thumb|[[Otto Lilienthal]] in mid-flight, c. 1895]]

===Antecedents===
Many stories from antiquity involve flight, such as the [[Greek mythology|Greek legend]] of [[Icarus (mythology)|Icarus]] and [[Daedalus]], and the [[Vimana]] in ancient [[Indian epic poetry|Indian epics]]. Around [[Ancient Greece|400 BC in Greece]], [[Archytas]] was reputed to have designed and built the first artificial, self-propelled flying device, a bird-shaped model propelled by a jet of what was probably steam, said to have flown some {{convert|200|m|sp=us|abbr=on}}.<ref>[[Aulus Gellius]], "Attic Nights", Book X, 12.9 at [http://penelope.uchicago.edu/Thayer/E/Roman/Texts/Gellius/10*.html LacusCurtius]</ref><ref>{{cite web|url=http://www.tmth.edu.gr/en/aet/1/14.html |title=Archytas of Tarentum, Technology Museum of Thessaloniki, Macedonia, Greece |publisher=Tmth.edu.gr |date= |accessdate=2013-05-30}}</ref> This machine may have been suspended for its flight.<ref>{{cite web|url=http://www.pressconnects.com/apps/pbcs.dll/article?AID=/20070104/NEWS02/701040323/1006/ |title=Modern rocketry |publisher=Pressconnects.com |date= |accessdate=2013-05-30}}</ref><ref>{{cite web|url=http://automata.co.uk/History%20page.htm |title=Automata history |publisher=Automata.co.uk |date= |accessdate=2013-05-30}}</ref>

Some of the earliest recorded attempts with [[Glider aircraft|gliders]] were those by the 9th-century poet [[Abbas ibn Firnas]] and the 11th-century monk [[Eilmer of Malmesbury]]; both experiments injured their pilots.<ref>White, Lynn. "Eilmer of Malmesbury, an Eleventh Century Aviator: A Case Study of Technological Innovation, Its Context and Tradition." ''[[Technology and Culture]]'', Volume 2, Issue 2, 1961, pp. 97–111 (97–99 resp. 100–101).</ref> [[Leonardo da Vinci]] researched the wing design of birds and designed a man-powered aircraft in his ''[[Codex on the Flight of Birds]]'' (1502).

In 1799, [[George Cayley]] set forth the concept of the modern airplane as a fixed-wing flying machine with separate systems for lift, propulsion, and control.<ref>{{cite web
| title = Aviation History
| url = http://www.aviation-history.com/early/cayley.htm
| publisher =
| accessdate =26 July 2009
| quote = In 1799 he set forth for the first time in history the concept of the modern aeroplane. Cayley had identified the drag vector (parallel to the flow) and the lift vector (perpendicular to the flow).}}</ref><ref>{{cite web
| title = Sir George Cayley (British Inventor and Scientist)
| url = http://www.britannica.com/EBchecked/topic/100795/Sir-George-Cayley-6th-Baronet
| publisher = Britannica
| accessdate =26 July 2009
| quote = English pioneer of aerial navigation and aeronautical engineering and designer of the first successful glider to carry a human being aloft. Cayley established the modern configuration of an airplane as a fixed-wing flying machine with separate systems for lift, propulsion, and control as early as 1799.}}</ref> Cayley was building and flying models of fixed-wing aircraft as early as 1803, and he built a successful passenger-carrying [[Glider aircraft|glider]] in 1853.<ref name="auto"/> In 1856, Frenchman [[Jean-Marie Le Bris]] made the first powered flight, by having his glider ''"L'Albatros artificiel"'' pulled by a horse on a beach.{{Citation needed|date=May 2011}} Then [[Alexander F. Mozhaisky]] also made some innovative designs. In 1883, the American [[John J. Montgomery]] made a controlled flight in a glider.<ref>The Journal of San Diego History, July 1968, Vol. 14, No. 3</ref> Other aviators who made similar flights at that time were [[Otto Lilienthal]], [[Percy Pilcher]], and [[Octave Chanute]].

Sir [[Hiram Maxim]] built a craft that weighed 3.5 tons, with a 110-foot (34-meter) wingspan that was powered by two 360-horsepower (270-kW) steam engines driving two propellers. In 1894, his machine was tested with overhead rails to prevent it from rising. The test showed that it had enough lift to take off. The craft was uncontrollable, which Maxim, it is presumed, realized, because he subsequently abandoned work on it.<ref>Beril, Becker (1967). ''Dreams and Realities of the Conquest of the Skies''. New York: Atheneum. pp. 124–125</ref>

In the 1890s, [[Lawrence Hargrave]] conducted research on wing structures and developed a [[box kite]] that lifted the weight of a man. His box kite designs were widely adopted. Although he also developed a type of rotary aircraft engine, he did not create and fly a powered fixed-wing aircraft.<ref>{{Cite book|last=Inglis|first=Amirah|chapter=Hargrave, Lawrence (1850–1915)|volume=9|title=Australian Dictionary of Biography|publisher=Melbourne University Press|url=http://adbonline.anu.edu.au/biogs/A090194b.htm|accessdate=5 July 2010}}</ref>

Between 1867 and 1896 the German pioneer of human aviation Otto Lilienthal developed heavier-than-air flight. He was the first person to make well-documented, repeated, successful gliding flights.

===Early powered flights===
The [[Wright brothers]] flights in 1903 are recognized by the ''[[Fédération Aéronautique Internationale]]'' (FAI), the standard setting and record-keeping body for [[aeronautics]], as "the first sustained and controlled heavier-than-air powered flight".<ref name="auto1"/> By 1905, the [[Wright Flyer III]] was capable of fully controllable, stable flight for substantial periods. The Wright brothers credited Otto Lilienthal as a major inspiration for their decision to pursue manned flight.

In 1906, [[Alberto Santos Dumont]] made what was claimed to be the first airplane flight unassisted by [[catapult]]<ref>{{cite web|url=http://www.airshowfan.com/first-airplane.htm|title=Bernardo Malfitano - AirShowFan.com|work=airshowfan.com|accessdate=1 April 2015}}</ref> and set the first world record recognized by the [[Aéro-Club de France]] by flying {{convert|220|m|sp=us|ft}} in less than 22 seconds.<ref>Jones, Ernest. [http://earlyaviators.com/edumonb.htm "Santos Dumont in France 1906–1916: The Very Earliest Early Birds."] ''earlyaviators.com'', 25 December 2006. Retrieved: 17 August 2009.</ref> This flight was also certified by the FAI.<ref>[http://www.aeroclub.com/santos_dumont_14bis_14bis.htm Les vols du 14bis relatés au fil des éditions du journal l'illustration de 1906.] The wording is: "cette prouesse est le premier vol au monde '''homologué''' par l'Aéro-Club de France et la toute jeune Fédération Aéronautique Internationale (FAI)."</ref><!--Armstrong, during his official tour of South American countries as a NASA ambassador, acknowledged Santos Dumont's role during addresses to Brazilian audiences. Please note - this reference does NOT include any acknowledgment of this role in Europe; any editor adding such a European claim should support it with a separate citation.--><ref>[http://www.aeroclub.com/santos_dumont_14bis_index.htm Santos-Dumont: Pionnier de l'aviation, dandy de la Belle Epoque.]{{dead link|date=May 2013}}</ref>

An early aircraft design that brought together the modern [[monoplane]] [[tractor configuration]] was the [[Bleriot VIII]] design of 1908. It had movable tail surfaces controlling both yaw and pitch, a form of roll control supplied either by wing warping or by ailerons and controlled by its pilot with a [[joystick]] and rudder bar. It was an important predecessor of his later [[Bleriot XI]] [[English Channel|Channel]]-crossing aircraft of the summer of 1909.<ref>{{cite book |title=Bleriot XI, The Story of a Classic Aircraft |last=Crouch |first=Tom |authorlink= |year=1982 |publisher=Smithsonian Institution Press |location= |isbn=0-87474-345-1 |page= |pages=21 and 22 |url=}}</ref>

In Romania the aircraft, [[Vlaicu Nr. I|A. Vlaicu nr. 1]], was finished in 1909, and was test flown on June 17, 1910. From the first flight the airplane had no need of changes. The plane was made from a single [[aluminum]] spar 10 meters long which supported the entire aircraft, making it very easy to fly. Ten planes were made for the Romanian Air Force, being the second-ever military air force in the world.

[[World War I]] served as a testbed for the use of the airplane as a weapon. Airplanes demonstrated their potential as mobile observation platforms, then proved themselves to be machines of war capable of causing casualties to the enemy. The earliest known aerial victory with a synchronized machine gun-armed [[fighter aircraft]] occurred in 1915, by German [[Luftstreitkräfte]] ''Leutnant'' [[Kurt Wintgens]]. [[Fighter aces]] appeared; the greatest (by number of Aerial Combat victories) was [[Manfred von Richthofen]].

Following WWI, aircraft technology continued to develop. [[Alcock and Brown]] crossed the Atlantic non-stop for the first time in 1919. The first international commercial flights took place between the United States and Canada in 1919.{{citation needed|date=March 2013}}<!-- Aircraft Transport and Travel (UK-France) and Chalk's International Airlines (US-Bahamas) suggest earlier/different -->

Airplanes had a presence in all the major battles of [[World War II]]. They were an essential component of the military strategies of the period, such as the German [[Blitzkrieg]], The [[Battle of Britain]], and the American and Japanese aircraft carrier campaigns of the [[Pacific War]].

===Development of jet aircraft===
The first 'operational' [[jet aircraft]] was the German [[Heinkel He 178]], which was tested in 1939. In 1943, the [[Messerschmitt Me 262]], the first 'operational' jet fighter aircraft, went into service in the German [[Luftwaffe]]. In October 1947, the [[Bell X-1]] was the first aircraft to exceed the speed of sound.<ref name=NTRS>Hallion, Richard, P. [https://www.yumpu.com/en/document/view/7095890/the-naca-nasa-and-the-supersonic-hypersonic-frontier "The NACA, NASA, and the Supersonic-Hypersonic Frontier."] ''NASA.'' Retrieved: 7 September 2011.</ref>

The first [[jet airliner]], the [[de Havilland Comet]], was introduced in 1952. The [[Boeing 707]], the first widely successful commercial jet, was in commercial service for more than 50 years, from 1958 to 2010. The [[Boeing 747]] was the world's biggest passenger aircraft from 1970 until it was surpassed by the [[Airbus A380]] in 2005.

==Propulsion==
{{See also|Powered aircraft|Aircraft engine}}

===Propeller engines===
{{Main|Propeller (aeronautics)}}
[[File:Antonov An-2 in Vitebsk.jpg|right|thumb|An [[Antonov An-2]] [[biplane]]]]

Smaller and older propeller planes make use of [[reciprocating engine]]s (or piston engines) to turn a [[Propeller (aircraft)|propeller]] to create thrust. The amount of thrust a propeller creates is determined by its disk area - the area in which the blades rotate. If the area is too small, efficiency is poor, and if the area is large, the propeller must rotate at a very low speed to avoid going supersonic and creating a lot of noise, and not much thrust. Because of this limitation, propellers are favored for planes which travel at below mach .5, while jets are a better choice above that speed. Propeller engines may be quieter than jet engines (though not always) and may cost less to purchase or maintain and so remain common on light general aviation aircraft such as the [[Cessna 172]]. Larger modern propeller planes such as the [[Bombardier Dash 8|Dash 8]] use a jet engine to turn the propeller, primarily because an equivalent piston engine in power output would be much larger and more complex.

===Jet engines===
{{Main|Jet engine}}
[[File:British Airways Concorde G-BOAC 03.jpg|right|thumb|The [[Concorde]] supersonic transport aircraft]]

[[Jet aircraft]] are propelled by [[jet engine]]s, which are used because the aerodynamic limitations of propellers do not apply to jet propulsion. These engines are much more powerful than a reciprocating engine for a given size or weight and are comparatively quiet and work well at higher altitude. Most modern jet planes use [[turbofan]] jet engines which balance the advantages of a propeller, while retaining the exhaust speed and power of a jet. This is essentially a ducted propeller attached to a jet engine, much like a turboprop, but with a smaller diameter. When installed on an airliner, it is efficient so long as it remains below the [[speed of sound]] (or subsonic). Jet fighters and other [[supersonic aircraft]] that do not spend a great deal of time supersonic also often use turbofans, but to function, air intake ducting is needed to slow the air down so that when it arrives at the front of the turbofan, it is subsonic. When passing through the engine, it is then re-accelerated back to supersonic speeds. To further boost the power output, fuel is dumped into the exhaust stream, where it ignites. This is called an [[afterburner]] and has been used on both pure jet aircraft and [[turbojet]] aircraft although it is only normally used on combat aircraft due to the amount of fuel consumed, and even then may only be used for short periods of time.  [[Supersonic transport|Supersonic airliners]] (e.g. [[Concorde]]) are no longer in use largely because flight at supersonic speed creates a [[sonic boom]] which is prohibited in most heavily populated areas, and because of the much higher consumption of fuel supersonic flight requires.

Jet aircraft possess high cruising speeds ({{convert|700|to|900|km/h|sp=us|abbr=on}}) and high speeds for [[takeoff]] and [[landing]] ({{convert|150|to|250|km/h|abbr=on}}). Due to the speed needed for takeoff and landing, jet aircraft use [[Flap (aircraft)|flaps]] and [[Leading edge slats|leading edge devices]] to control the lift and speed. Many jet aircraft also use [[thrust reverser]]s to slow down the aircraft upon landing.

===Electric engines===
{{Main|Electric motor}}
An [[electric aircraft]] runs on [[electric motor]]s rather than [[internal combustion engine]]s, with [[electricity]] coming from [[fuel cell]]s, [[solar cell]]s, [[ultracapacitors]], [[power beaming]],<ref>[http://www.dfrc.nasa.gov/gallery/Photo/Power-Beaming/index.html Power Beaming]. Dfrc.nasa.gov.</ref> or [[battery (electricity)|batteries]]. Currently, flying electric aircraft are mostly experimental prototypes, including manned and [[unmanned aerial vehicle]]s, but there are some production models on the market already.<ref>[http://www.avweb.com/avwebflash/news/PipistrelExpandsElectricAircraftLine_208598-1.html Pipistrel Expands Electric Aircraft Line] (2013)</ref>

===Rocket engines===
{{Main|Rocket engine}}
[[File:X-1-1 In Flight - GPN-2000-000134.jpg|thumb|right|[[Bell X-1]] in flight, 1947]]

In [[World War II]], the Germans deployed the [[Messerschmitt Me 163|Me 163 Komet]] [[rocket-powered aircraft]]. The first plane to break the [[sound barrier]] in level flight was a rocket plane – the [[Bell X-1]]. The later [[North American X-15]] broke many speed and [[Flight altitude record|altitude records]] and laid much of the groundwork for later aircraft and spacecraft design. Rocket aircraft are not in common usage today, although [[rocket-assisted take off]]s are used for some military aircraft. Recent rocket aircraft include the [[Scaled Composites SpaceShipOne|SpaceShipOne]] and the [[XCOR EZ-Rocket]].
{{clear}}

===Ramjet and scramjet engines===
{{Main|Ramjet|Scramjet}}
[[File:X43a2 nasa scramjet.jpg|thumb|left|Artist's concept of X-43A with [[scramjet]] attached to the underside]]
A ramjet is a form of jet engine that contains no major moving parts and can be particularly useful in applications requiring a small and simple engine for high-speed use, such as with missiles. Ramjets require forward motion before they can generate thrust and so are often used in conjunction with other forms of propulsion, or with an external means of achieving sufficient speed. The [[Lockheed D-21]] was a Mach 3+ ramjet-powered reconnaissance drone that was launched from a [[parent aircraft]]. A ramjet uses the vehicle's forward motion to force air through the engine without resorting to turbines or vanes. Fuel is added and ignited, which heats and expands the air to provide thrust.

A scramjet is a supersonic ramjet and aside from differences with dealing with internal supersonic airflow works like a conventional ramjet. This type of engine requires a very high initial speed in order to work. The [[NASA X-43]], an experimental unmanned scramjet, set a world speed record in 2004 for a jet-powered aircraft with a speed of Mach 9.7, nearly {{convert|sp=us|7500|mph}}.

==Design and manufacture==
{{main|Aerospace manufacturer}}
[[File:SR71 factoryfloor SkunkWorks.jpg|thumb|alt=SR-71 at Lockheed Skunk Works|Assembly line of the [[Lockheed SR-71 Blackbird|SR-71 Blackbird]] at [[Skunk Works]], [[Lockheed Martin]]’s Advanced Development Programs (ADP).]]

Most airplanes are constructed by companies with the objective of producing them in quantity for customers. The design and planning process, including safety tests, can last up to four years for small turboprops or longer for larger planes.

During this process, the objectives and design specifications of the aircraft are established. First the construction company uses drawings and equations, simulations, wind tunnel tests and experience to predict the behavior of the aircraft. Computers are used by companies to draw, plan and do initial simulations of the aircraft. Small models and mockups of all or certain parts of the plane are then tested in wind tunnels to verify its aerodynamics.

When the design has passed through these processes, the company constructs a limited number of prototypes for testing on the ground. Representatives from an aviation governing agency often make a first flight. The flight tests continue until the aircraft has fulfilled all the requirements. Then, the governing public agency of aviation of the country authorizes the company to begin production.

In the United States, this agency is the [[Federal Aviation Administration]] (FAA), and in the European Union, [[European Aviation Safety Agency]] (EASA). In Canada, the public agency in charge and authorizing the mass production of aircraft is [[Transport Canada]].

In the case of international sales, a license from the public agency of aviation or transport of the country where the aircraft is to be used is also necessary. For example, airplanes made by the European company, [[Airbus]], need to be certified by the FAA to be flown in the United States, and airplanes made by U.S.-based [[Boeing]] need to be approved by the EASA to be flown in the European Union.

[[File:A321 final assembly (9351765668).jpg|thumb|left|An [[Airbus A321]] on [[Assembly line|final assembly line]] 3 in the Airbus plant at [[Hamburg Finkenwerder Airport]].]]

Quieter planes are becoming more and more necessary due to the increase in air traffic, particularly over urban areas, as [[aircraft noise]] pollution is a major concern.

Small planes can be designed and constructed by amateurs as homebuilts. Other [[homebuilt aircraft]] can be assembled using pre-manufactured kits of parts that can be assembled into a basic plane and must then be completed by the builder.

There are few companies that produce planes on a large scale. However, the production of a plane for one company is a process that actually involves dozens, or even hundreds, of other companies and plants, that produce the parts that go into the plane. For example, one company can be responsible for the production of the landing gear, while another one is responsible for the radar. The production of such parts is not limited to the same city or country; in the case of large plane manufacturing companies, such parts can come from all over the world.

The parts are sent to the main plant of the plane company, where the production line is located. In the case of large planes, production lines dedicated to the assembly of certain parts of the plane can exist, especially the wings and the fuselage.

When complete, a plane is rigorously inspected to search for imperfections and defects. After approval by inspectors, the plane is put through a series of [[flight test]]s to assure that all systems are working correctly and that the plane handles properly. Upon passing these tests, the plane is ready to receive the "final touchups" (internal configuration, painting, etc.), and is then ready for the customer.

==Characteristics==
[[File:IAI Heron 1 in flight 2.JPEG|thumb|right|An [[IAI Heron]] - an [[unmanned aerial vehicle]] with a [[twin boom|twin-boom]] configuration]]

===Airframe===
{{Main|Airframe}}
The structural parts of a fixed-wing aircraft are called the airframe. The parts present can vary according to the aircraft's type and purpose. Early types were usually made of wood with fabric wing surfaces, When engines became available for powered flight around a hundred years ago, their mounts were made of metal. Then as speeds increased more and more parts became metal until by the end of WWII all-metal aircraft were common. In modern times, increasing use of [[composite material]]s has been made.

Typical structural parts include:

* One or more large horizontal ''wings'', often with an [[airfoil]] cross-section shape. The wing deflects air downward as the aircraft moves forward, generating [[Lift (force)|lifting force]] to support it in flight. The wing also provides stability in [[Flight dynamics (aircraft)|roll]] to stop the aircraft from rolling to the left or right in steady flight.

[[File:Antonov 225 (2010).jpg|thumb|right|The [[An-225 Mriya]], which can carry a 250-tonne payload, has two vertical stabilisers.]]

* A ''[[fuselage]]'', a long, thin body, usually with tapered or rounded ends to make its shape [[aerodynamically]] smooth. The fuselage joins the other parts of the airframe and usually contains important things such as the pilot, payload and flight systems.
* A ''[[vertical stabilizer]]'' or fin is a vertical wing-like surface mounted at the rear of the plane and typically protruding above it. The fin stabilizes the plane's [[Flight dynamics (aircraft)|yaw]] (turn left or right) and mounts the [[rudder]] which controls its rotation along that axis.
* A ''[[horizontal stabilizer]]'' or [[tailplane]], usually mounted at the tail near the vertical stabilizer. The horizontal stabilizer is used to stabilize the plane's [[Flight dynamics (aircraft)|pitch]] (tilt up or down) and mounts the [[Elevator (aircraft)|elevators]] which provide pitch control.
* ''[[Landing gear]]'', a set of wheels, skids, or floats that support the plane while it is on the surface. On seaplanes the bottom of the fuselage or floats (pontoons) support it while on the water. On some planes the landing gear retracts during flight to reduce drag.

===Wings===
{{Main|Wing}}
The wings of a fixed-wing aircraft are static planes extending either side of the aircraft. When the aircraft travels forwards, 
air flows over the wings which are shaped to create lift. This shape is called an [[airfoil]] and is shaped like a bird's wing.

====Wing structure====
Airplanes have flexible wing surfaces which are stretched across a frame and made rigid by the lift forces exerted by the airflow over them. Larger aircraft have rigid wing surfaces which provide additional strength.

Whether flexible or rigid, most wings have a strong frame to give them their shape and to transfer lift from the wing surface to the rest of the aircraft. The main structural elements are one or more spars running from root to tip, and many ribs running from the leading (front) to the trailing (rear) edge.

Early airplane engines had little power, and lightness was very important. Also, early airfoil sections were very thin, and could not have a strong frame installed within. So until the 1930s most wings were too lightweight to have enough strength and external bracing struts and wires were added. When the available engine power increased during the 1920s and 30s, wings could be made heavy and strong enough that bracing was not needed any more. This type of unbraced wing is called a cantilever wing.

====Wing configuration====
{{main|Wing configuration}}
[[File:Morane-Saulnier Type L - Captured with german insigna.jpg|thumb|Captured [[Morane-Saulnier L]] wire-braced parasol monoplane]]
The number and shape of the wings varies widely on different types. A given wing plane may be full-span or divided by a central [[fuselage]] into port (left) and starboard (right) wings. Occasionally even more wings have been used, with the three-winged [[triplane]] achieving some fame in WWI. The four-winged [[quadruplane]] and other [[multiplane]] designs have had little success.

A [[monoplane]] has a single wing plane, a [[biplane]] has two stacked one above the other, a [[tandem wing]] has two placed one behind the other. When the available engine power increased during the 1920s and 30s and bracing was no longer needed, the unbraced or cantilever monoplane became the most common form of powered type.

The wing [[planform (aeronautics)|planform]] is the shape when seen from above. To be aerodynamically efficient, a wing should be straight with a long span from side to side but have a short chord (high [[aspect ratio]]). But to be structurally efficient, and hence light weight, a wing must have a short span but still enough area to provide lift (low aspect ratio).

At transonic speeds (near the [[speed of sound]]), it helps to sweep the wing backwards or forwards to reduce drag from supersonic shock waves as they begin to form. The [[swept wing]] is just a straight wing swept backwards or forwards.

[[File:Dassault Mirage G8.jpg|thumb|Two [[Dassault Mirage G]] prototypes, one with wings swept]]

The [[delta wing]] is a triangle shape which may be used for a number of reasons. As a flexible [[Rogallo wing]] it allows a stable shape under aerodynamic forces, and so is often used for ultralight aircraft and even [[kites]]. As a supersonic wing it combines high strength with low drag and so is often used for fast jets.

A variable geometry wing can be changed in flight to a different shape. The [[variable sweep wing|variable-sweep wing]] transforms between an efficient straight configuration for takeoff and landing, to a low-drag swept configuration for high-speed flight. Other forms of variable planform have been flown, but none have gone beyond the research stage.

===Fuselage===
{{Main|Fuselage}}
A ''[[fuselage]]'' is a long, thin body, usually with tapered or rounded ends to make its shape [[aerodynamically]] smooth. The fuselage may contain the [[flight crew]], passengers, cargo or [[payload (air and space craft)|payload]], fuel and engines. The pilots of manned aircraft operate them from a ''[[Cockpit (aviation)|cockpit]]'' located at the front or top of the fuselage and equipped with controls and usually windows and instruments. A plane may have more than one fuselage, or it may be fitted with booms with the tail located between the booms to allow the extreme rear of the fuselage to be useful for a variety of purposes.

===Wings vs. bodies===

====Flying wing====
{{main|Flying wing}}
[[File:USAF B-2 Spirit.jpg|thumb|right|The US-produced [[B-2 Spirit]] is a [[strategic bomber]]. It has a flying wing configuration and is capable of intercontinental missions]]
A flying wing is a [[tailless aircraft|tailless]] aircraft which has no definite [[fuselage]]. Most of the crew, payload and equipment are housed inside the main wing structure.<ref name="Crane">Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 224. Aviation Supplies & Academics, 1997. ISBN 1-56027-287-2</ref>

The flying wing configuration was studied extensively in the 1930s and 1940s, notably by [[Jack Northrop]] and [[Cheston L. Eshelman]] in the United States, and [[Alexander Lippisch]] and the [[Horten brothers]] in Germany.
After the war, a number of experimental designs were based on the flying wing concept, but the known difficulties remained intractable. Some general interest continued until the early 1950s but designs did not necessarily offer a great advantage in range and presented a number of technical problems, leading to the adoption of "conventional" solutions like the [[Convair B-36]] and the [[B-52 Stratofortress]]. Due to the practical need for a deep wing, the flying wing concept is most practical for designs in the slow-to-medium speed range, and there has been continual interest in using it as a tactical [[airlift]]er design.

Interest in flying wings was renewed in the 1980s due to their potentially low [[radar]] reflection cross-sections. [[Stealth technology]] relies on shapes which only reflect radar waves in certain directions, thus making the aircraft hard to detect unless the radar receiver is at a specific position relative to the aircraft - a position that changes continuously as the aircraft moves. This approach eventually led to the Northrop [[B-2 Spirit]] [[Stealth aircraft|stealth]] bomber. In this case the aerodynamic advantages of the flying wing are not the primary needs. However, modern computer-controlled [[fly-by-wire]] systems allowed for many of the aerodynamic drawbacks of the flying wing to be minimized, making for an efficient and stable long-range bomber.

====Blended wing body====
{{main|Blended wing}}
[[File:NASA BWB.jpg|thumb|right|300px|Computer-generated model of the [[Boeing X-48]]]]
Blended wing body aircraft have a flattened and airfoil shaped body, which produces most of the lift to keep itself aloft, and distinct and separate wing structures, though the wings are smoothly blended in with the body.

Thus blended wing bodied aircraft incorporate design features from both a futuristic fuselage and flying wing design. The purported advantages of the blended wing body approach are efficient high-lift wings and a wide [[airfoil]]-shaped body. This enables the entire craft to contribute to [[lift (force)|lift]] generation with the result of potentially increased fuel economy.

====Lifting body====
[[File:X24.jpg|thumb|left|The Martin Aircraft Company [[Martin-Marietta X-24|X-24]] was built as part of a 1963 to 1975 experimental US military program.]]
{{main|Lifting body}}
A lifting body is a configuration in which the body itself produces [[lift (force)|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. Whereas a flying wing seeks to maximize cruise efficiency at [[Subsonic flight|subsonic]] speeds by eliminating non-lifting surfaces, lifting bodies generally minimize the drag and structure of a wing for subsonic, [[supersonic]], and [[hypersonic]] flight, or, [[spacecraft]] [[re-entry]]. All of these flight regimes pose challenges for proper flight stability.

Lifting bodies were a major area of research in the 1960s and 70s as a means to build a small and lightweight manned spacecraft. The US built a number of famous lifting body rocket planes to test the concept, as well as several rocket-launched re-entry vehicles that were tested over the Pacific. Interest waned as the [[US Air Force]] lost interest in the manned mission, and major development ended during the [[Space Shuttle design process]] when it became clear that the highly shaped fuselages made it difficult to fit fuel tankage.
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===Empennage and foreplane===
{{main|Empennage|Canard (aeronautics)}}
[[File:SaabViggen Canards.jpg|thumb|Canards on the [[Saab Viggen]]]]
The classic [[airfoil]] section wing is unstable in flight and difficult to control. Flexible-wing types often rely on an anchor line or the weight of a pilot hanging beneath to maintain the correct attitude. Some free-flying types use an adapted airfoil that is stable, or other ingenious mechanisms including, most recently, electronic artificial stability.

But in order to achieve trim, stability and control, most fixed-wing types have an [[empennage]] comprising a fin and rudder which act horizontally and a tailplane and elevator which act vertically. This is so common that it is known as the conventional layout. Sometimes there may be two or more fins, spaced out along the tailplane.

Some types have a horizontal "[[Canard (aeronautics)|canard]]" foreplane ahead of the main wing, instead of behind it.<ref name="Crane1">Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', page 86. Aviation Supplies & Academics, 1997. ISBN 1-56027-287-2</ref><ref name="GroundUp">Aviation Publishers Co. Limited, ''From the Ground Up'', page 10 (27th revised edition) ISBN 0-9690054-9-0</ref><ref name="FAR1.1">{{cite web|url = http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=49436e70336dc8d8f1ab7b3d789254af&rgn=div8&view=text&node=14:1.0.1.1.1.0.1.1&idno=14|title = Title 14: Aeronautics and Space - PART 1—DEFINITIONS AND ABBREVIATIONS|accessdate =5 August 2008|last = [[Federal Aviation Administration]]|authorlink = |date=August 2008}}</ref> This foreplane may contribute to the lift, the trim, or control of the aircraft, or to several of these.

===Controls and instruments===
{{main|Aircraft flight control system}}
[[File:robin.dr400slash500.g-rndd.arp.jpg|left|thumb|A light aircraft ([[Avions Robin|Robin]] DR400/500) cockpit]]
{{Further|Fixed-wing aircraft#Aircraft controls|Fixed-wing aircraft#Cockpit instrumentation}}
<!--[[File:Six flight instruments.JPG|thumb|Six basic flight instruments]]-->
Airplanes have complex [[Aircraft flight control system|flight control system]]s. The main controls allow the pilot to direct the aircraft in the air by controlling the [[Aircraft attitude|attitude]] (roll, pitch and yaw) and engine thrust.

On manned aircraft, [[cockpit]] instruments provide information to the pilots, including [[Flight instruments|flight data]], [[Aircraft engine|engine output]], navigation, communications and other aircraft systems that may be installed.
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==Safety==
{{Main|Air safety}}

When risk is measured by deaths per passenger kilometer, air travel is approximately 10 times safer than travel by bus or rail. However, when using the deaths per journey statistic, air travel is significantly more dangerous than car, rail, or bus travel.<ref>[http://www.numberwatch.co.uk/risks_of_travel.htm The risks of travel]. Numberwatch.co.uk.</ref> Air travel insurance is relatively expensive for this reason- insurers generally use the deaths per journey statistic.<ref>[http://space.newscientist.com/article/mg16321985.200-flight-into-danger.html Flight into danger - 7 August 1999 - New Scientist Space]. Space.newscientist.com (7 August 1999).</ref> There is a significant difference between the safety of airliners and that of smaller private planes, with the per-mile statistic indicating that airliners are 8.3 times safer than smaller planes.<ref>{{citation|title=Is GA Flying Safer Than Driving?|url=http://www.meretrix.com/~harry/flying/notes/safetyvsdriving.html|first=Harry|last=Mantakos|accessdate=13 May 2012}}</ref>

==See also==
{{Portal|Aviation}}
* [[Abbas Ibn Firnas]]
* [[Aircraft flight mechanics]]
* [[Airliner]]
* [[Aviation]]
* [[Aviation and the environment]]
* [[Aviation history]]
* [[Fuel efficiency]]
* [[List of altitude records reached by different aircraft types]]
* [[Maneuvering speed]]
* [[Rotorcraft]]
* [[Wright Brothers]]

==References==
:{{note|Alpha|A|Rare alternative spelling: æroplane}}
{{Reflist|33em}}

==Bibliography==
* Blatner, David. ''The Flying Book: Everything You've Ever Wondered About Flying On Airplanes''. ISBN 0-8027-7691-4

==External links==
 {{Wikiquote}}
{{Wiktionary|aeroplane|aircraft|airplane}}
{{Commons category|Aircraft by type of wing}}
* [http://www.aerocentre.blogspot.com/ The Aeroplane centre]
* [http://www.airliners.net/info/ Airliners.net]
* [http://www.aerospaceweb.org/ Aerospaceweb.org]
* [http://travel.howstuffworks.com/airplane.htm How Airplanes Work – Howstuffworks.com]

{{Aircraft types (by method of thrust and lift)}}

{{Authority control}}

{{DEFAULTSORT:Airplane}}
[[Category:Aircraft configurations]]
[[Category:American inventions]]
[[Category:1903 introductions]]