Editing Fixed-wing aircraft (section)

==Characteristics==
[[Image:IAI Heron 1 in flight 2.JPEG|thumb|The [[IAI Heron]] is an [[unmanned aerial vehicle]] (UAV) with a [[twin-boom]] configuration]]

===Air frame===
{{main|Airframe}}
The structural element of a fixed-wing aircraft is the air frame. It varies according to the aircraft's type, purpose, and technology. Early airframes were made of wood with fabric wing surfaces, When engines became available for powered flight, their mounts were made of metal. As speeds increased metal became more common until by the end of World War II, all-metal (and glass) aircraft were common. In modern times, [[composite material]]s became more common.

Typical structural elements include:

* One or more mostly horizontal wings, often with an [[airfoil]] cross-section. The wing deflects air downward as the aircraft moves forward, generating [[Lift (force)|lifting force]] to support it in flight. The wing also provides lateral stability to stop the aircraft level in steady flight. Other roles are to hold the fuel and mount the engines.
[[Image:Antonov 225 (2010).jpg|thumb|The [[An-225 Mriya]], which was the largest airplane in the world, could carry a 250-tonne payload, had two vertical stabilizers.]]
* A [[fuselage]], typically a long, thin body, usually with tapered or rounded ends to make its shape [[aerodynamically]] slippery. The fuselage joins the other parts of the air frame and contains the payload, and flight systems.
* A [[vertical stabilizer]] or fin is a rigid 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]], 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]] that provide pitch control.
* [[Landing gear]], a set of wheels, skids, or floats that support the plane while it is not in flight. On seaplanes, the bottom of the fuselage or floats (pontoons) support it while on the water. On some planes, the landing gear retracts during the flight to reduce drag.

===Wings===
The wings of a fixed-wing aircraft are static planes extending to either side of the aircraft. When the aircraft travels forwards, air flows over the wings that are shaped to create lift.

====Structure====

Kites and some lightweight gliders and airplanes have flexible wing surfaces that are stretched across a frame and made rigid by the lift forces exerted by the airflow over them. Larger aircraft have rigid wing surfaces.

Whether flexible or rigid, most wings have a strong frame to give them 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 ribs running from the leading (front) to the trailing (rear) edge.

[[file:Wing Components.png|thumb|right|Major components of a rigid wing.]]

Early airplane engines had little power and light weight was critical. Also, early airfoil sections were thin, and could not support a strong frame. Until the 1930s, most wings were so fragile that external bracing struts and wires were added. As engine power increased, wings could be made heavy and strong enough that bracing was unnecessary. Such an unbraced wing is called a [[cantilever]] wing.

====Configuration====
{{main|Wing configuration|Wing}}
[[File:Morane-Saulnier Type L - Captured with german insigna.jpg|thumb|Captured [[Morane-Saulnier L]] wire-braced parasol monoplane]]
The number and shape of wings vary widely. Some designs blend the wing with the fuselage, while left and right wings separated by the fuselage are more common. 

Occasionally more wings have been used, such as the three-winged [[triplane]] from World War I. Four-winged [[quadruplane|quadruplanes]] and other [[Multiplane (aeronautics)|multiplane]] designs have had little success.

Most planes are [[monoplane]]s, with one or two parallel wings. [[biplane|Biplanes]] and [[Triplane|triplanes]] stack one wing above the other.  [[tandem wing|Tandem wings]] place one wing behind the other, possibly joined at the tips. When the available engine power increased during the 1920s and 1930s and bracing was no longer needed, the unbraced or cantilever monoplane became the most common form.

The [[planform (aeronautics)|planform]] is the shape when seen from above/below. To be aerodynamically efficient, wings are straight with a long span, but a short chord (high [[aspect ratio]]). To be structurally efficient, and hence lightweight, wingspan must be as small as possible, but offer enough area to provide lift.

To travel at [[transonic]] speeds, variable geometry wings change orientation, angling backward to reduce drag from supersonic shock waves. 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. The [[swept wing]] is a straight wing swept backward or forwards.

[[Image:Dassault Mirage G8.jpg|thumb|Two [[Dassault Mirage G]] prototypes, one with wings swept (top)]]

The [[delta wing]] is a triangular shape that serves various purposes. As a flexible [[Rogallo wing]], it allows a stable shape under aerodynamic forces, and is often used for kites and other ultralight craft. It is supersonic capable, combining high strength with low drag.

Wings are typically hollow, also serving as fuel tanks. They are equipped with [[Flap (aeronautics)|flaps]], which allow the wing to increase/decrease drag/lift, for take-off and landing, and acting in opposition, to change direction.

===Fuselage===
{{Main|Fuselage}}

The fuselage is typically long and thin, usually with tapered or rounded ends to make its shape [[aerodynamically]] smooth. Most fixed-wing aircraft have a single fuselage. Others may have multiple fuselages, or the fuselage may be fitted with booms on either side of the tail to allow the extreme rear of the fuselage to be utilized.

The fuselage typically carries the [[flight crew]], passengers, cargo, and sometimes fuel and engine(s). [[Glider (aircraft)|Glider]]s typically omit fuel and engines, although some variations such as [[motor glider]]s and [[rocket glider]]s have them for temporary or optional use.

Pilots of manned commercial fixed-wing aircraft control them from inside a [[Cockpit (aviation)|cockpit]] within the fuselage, typically located at the front/top, equipped with controls, windows, and instruments, separated from passengers by a secure door. In small aircraft, the passengers typically sit behind the pilot(s) in the cabin, Occasionally, a passenger may sit beside or in front of the pilot. Larger [[Airliner|passenger aircraft]] have a separate passenger cabin or occasionally cabins that are physically separated from the cockpit.

Aircraft often have two or more pilots, with one in overall command (the "pilot") and one or more "co-pilots". On larger aircraft a [[navigator]] is typically also seated in the cockpit as well. Some military or specialized aircraft may have other flight crew members in the cockpit as well.

===Wings vs. bodies===

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

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, numerous experimental designs were based on the flying wing concept. General interest continued into the 1950s, but designs did not offer a great advantage in range and presented technical problems. The flying wing is most practical for designs in the slow-to-medium speed range, and drew continual interest as a tactical [[airlift]]er design.

Interest in flying wings reemerged in the 1980s due to their potentially low [[Radar cross section|radar cross-sections]]. [[Stealth technology]] relies on shapes that reflect radar waves only in certain directions, thus making it harder to detect. This approach eventually led to the Northrop [[B-2 Spirit]] [[Stealth aircraft|stealth]] bomber (pictured). The flying wing's aerodynamics are not the primary concern. Computer-controlled [[fly-by-wire]] systems compensated for many of the aerodynamic drawbacks, enabling an efficient and stable long-range aircraft.
====Blended wing body====
{{main|Blended wing}}
[[Image:NASA BWB.jpg|thumb|300px|Computer-generated model of the [[Boeing X-48]]]]
Blended wing body aircraft have a flattened airfoil-shaped body, which produces most of the lift to keep itself aloft, and distinct and separate wing structures, though the wings are blended with the body.

Blended wing bodied aircraft incorporate design features from both fuselage and flying wing designs. 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 potentially increased fuel economy.

====Lifting body====
[[Image:X24.jpg|thumb|The Martin Aircraft Company [[Martin-Marietta X-24|X-24]] was built as part of a 1963–1975 experimental US military program]]
{{main|Lifting body}}
A lifting body is a configuration in which the body 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 flight stability.

Lifting bodies were a major area of research in the 1960s and 1970s as a means to build small and lightweight manned spacecraft. The US built lifting body rocket planes to test the concept, as well as several rocket-launched re-entry vehicles. 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 highly shaped fuselages made it difficult to fit fuel tanks.
{{clear}}

===Empennage and foreplane===
{{main|Empennage|Canard (aeronautics)}}
The classic airfoil section wing is unstable in flight. Flexible-wing planes 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 mechanisms including electronic artificial stability.

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

[[File:SaabViggen Canards.jpg|thumb|Canards on the [[Saab Viggen]]]]
Some types have a horizontal "[[Canard (aeronautics)|canard]]" foreplane ahead of the main wing, instead of behind it.<ref name="Crane" />{{rp|86}}<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://www.ecfr.gov/cgi-bin/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|access-date = 5 August 2008|last = Federal Aviation Administration|author-link = Federal Aviation Administration|date = August 2008|archive-url = https://web.archive.org/web/20131220152531/http://www.ecfr.gov/cgi-bin/text-idx?c=ecfr&sid=49436e70336dc8d8f1ab7b3d789254af&rgn=div8&view=text&node=14:1.0.1.1.1.0.1.1&idno=14|archive-date = 20 December 2013|url-status = dead}}</ref> This foreplane may contribute to the trim, stability or control of the aircraft, or to several of these.

===Aircraft controls===

====Kite control====
Kites are controlled by one or more tethers.

====Free-flying aircraft controls====
{{Main|Aircraft flight control system}}
Gliders and airplanes have sophisticated control systems, especially if they are piloted.[[File:Pilotska kabina zrakoplova.JPG|thumb|Typical light aircraft ([[Cessna 150]]M) cockpit with control yokes]]
The controls allow the pilot to direct the aircraft in the air and on the ground. Typically these are:
*The [[yoke (aircraft)|yoke]] or [[joystick]] controls rotation of the plane about the pitch and roll axes. A [[yoke (aircraft)|yoke]] resembles a steering wheel. The pilot can pitch the plane down by pushing on the yoke or joystick, and pitch the plane up by pulling on it. Rolling the plane is accomplished by turning the yoke in the direction of the desired roll, or by tilting the joystick in that direction.
*[[Rudder]] pedals control rotation of the plane about the yaw axis. Two pedals pivot so that when one is pressed forward the other moves backward, and vice versa. The pilot presses on the right rudder pedal to make the plane yaw to the right, and pushes on the left pedal to make it yaw to the left. The rudder is used mainly to balance the plane in turns, or to compensate for winds or other effects that push the plane about the yaw axis.
*On powered types, an engine stop control ("fuel cutoff", for example) and, usually, a [[Throttle]] or [[thrust lever]] and other controls, such as a fuel-mixture control (to compensate for air density changes with altitude change).

Other common controls include:
*[[Flap (aircraft)|Flap]] levers, which are used to control the deflection position of flaps on the wings.
*[[Spoiler (aeronautics)|Spoiler]] levers, which are used to control the position of spoilers on the wings, and to arm their automatic deployment in planes designed to deploy them upon landing. The spoilers reduce lift for landing.
*[[Trim tab|Trim]] controls, which usually take the form of knobs or wheels and are used to adjust pitch, roll, or yaw trim. These are often connected to small airfoils on the trailing edge of the control surfaces and are called "trim tabs". Trim is used to reduce the amount of pressure on the control forces needed to maintain a steady course.
*On wheeled types, [[brake]]s are used to slow and stop the plane on the ground, and sometimes for turns on the ground.

A craft may have two pilot seats with dual controls, allowing two to take turns. 

The control system may allow full or partial automation, such as an [[autopilot]], a wing leveler, or a [[flight management system]]. An [[Unmanned aerial vehicle|unmanned aircraft]] has no pilot and is controlled remotely or via gyroscopes, computers/sensors or other forms of autonomous control.

===Cockpit instrumentation===
On manned fixed-wing aircraft, instruments provide information to the pilots, including [[Flight instruments|flight]], [[Aircraft engine|engines]], [[Air navigation|navigation]], [[Aviation communication|communications]], and other aircraft systems that may be installed.
[[File:Six flight instruments.JPG|thumb|upright=1.1|The six basic flight instruments.<br/>Top row (left to right): airspeed indicator, attitude indicator, altimeter.<br/>Bottom row (left to right): turn coordinator, heading indicator, vertical speed indicator.]]
The six basic instruments, sometimes referred to as the six pack, are:<ref name=6pack>{{cite web|title=Six Pack – The Primary Flight Instruments|url=http://www.learntofly.ca/six-pack-primary-flight-instruments/|publisher=LearnToFly.ca|access-date=31 January 2011|archive-url=https://web.archive.org/web/20110319004119/http://www.learntofly.ca/six-pack-primary-flight-instruments/|archive-date=19 March 2011|url-status=live|date=13 March 2010}}</ref>
* The [[airspeed indicator]] (ASI) shows the speed at which the plane is moving through the air.
* The [[attitude indicator]] (AI), sometimes called the artificial horizon, indicates the exact orientation of the aircraft about its [[Aircraft principal axes|pitch and roll axes]].
* The [[altimeter]] indicates the altitude or height of the plane [[Metres above sea level|above mean sea level]] (AMSL).
* The [[vertical speed indicator]] (VSI), or variometer, shows the rate at which the plane is [[Climb (aeronautics)|climbing]] or [[Descent (aeronautics)|descending]].
* The [[heading indicator]] (HI), sometimes called the directional gyro (DG), shows the [[Heading (navigation)|magnetic compass orientation]] of the fuselage. The [[Course (navigation)|direction]] is affected by wind conditions and [[magnetic declination]].
* The [[Turn and slip indicator#turn coordinator|turn coordinator]] (TC), or turn and bank indicator, helps the pilot to control the plane in a coordinated [[Orientation (geometry)|attitude]] while turning.

Other cockpit instruments include:
* A [[two-way radio]], to enable communications with other planes and with [[air traffic control]]. 
* A [[horizontal situation indicator]] (HSI) indicates the position and movement of the plane as seen from above with respect to the ground, including course/heading and other information.
* Instruments showing the status of the plane's engines ([[Engine#Speed|operating speed]], [[Engine#Thrust|thrust]], [[Operating temperature|temperature]], and other variables).
* Combined display systems such as [[primary flight display]]s or [[navigation aid]]s.
* Information displays such as onboard [[weather radar]] displays.
* A [[radio direction finder]] (RDF), to indicate the direction to one or more radio beacons, which can be used to determine the plane's position.
* A [[satellite navigation]] (satnav) system, to provide an accurate position.
Some or all of these instruments may appear on a computer display and be operated with touches, ala a phone.