"Flying machine" redirects here. For other uses see Flying machine (disambiguation). This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (January 2009) An Airbus A380 the world's largest passenger airliner Part of a series on Categories of aircraft Supported by lighter-than-air gases (aerostats) Unpowered Powered Balloon Airship Supported by LTA gases + aerodynamic lift Unpowered Powered Hybrid moored balloon Kytoon Hybrid airship Supported by aerodynamic lift (aerodynes) Unpowered Powered Unpowered fixed-wing Powered fixed-wing Glider Hang gliders Paraglider Kite Powered airplane (aeroplane) Powered hang gliders Powered paraglider Flettner airplane Ground-effect vehicle Powered hybrid fixed/rotary wing Tiltwing Tiltrotor Coleopter Unpowered rotary-wing Powered rotary-wing Rotor kite Autogyro Gyrodyne ("Heliplane") Helicopter Powered aircraft driven by flapping Ornithopter Other means of lift Unpowered Powered Hovercraft Flying Bedstead Avrocar A hot air balloon (aircraft) in flight.

Aircraft are vehicles which are able to fly by being supported by the air or in general the atmosphere of a planet. An aircraft counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil or in a few cases the downward thrust from jet engines.1

Although rockets and missiles also travel through the atmosphere most are not considered aircraft because they use rocket thrust instead of aerodynamics as the primary means of lift. However rocket planes and cruise missiles are considered aircraft because they rely on lift from the air. Another type of aircraft is the spaceplane which is an aircraft designed to fly up to extreme altitudes into space and land as a conventional aircraft.

The human activity which surrounds aircraft is called aviation. Manned aircraft are flown by an onboard pilot. Unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Target drones are an example of UAVs. Aircraft may be classified by different criteria such as lift type propulsion usage and others. Contents 1 History 2 Methods of lift 2.1 Lighter than air aerostats 2.2 Heavier than air aerodynes 2.2.1 Fixed-wing 2.2.2 Rotorcraft 2.2.3 Other methods of lift 3 Propulsion 3.1 Unpowered 3.1.1 Gliders 3.1.2 Balloons 3.1.3 Kites 3.2 Powered 3.2.1 Propeller 3.2.2 Jet 3.2.3 Helicopters 3.2.4 Other methods of propulsion 4 General construction 4.1 Airframe 4.2 Undercarriage 4.3 Fuselage 4.4 Wing configuration 4.5 Aircraft engine 4.6 Propellant tanks 4.7 Flight control surfaces 4.8 Empennage 4.9 Flight deck 4.10 Cabin 5 Performance of aircraft 5.1 Flight envelope 5.2 Aircraft range 6 Aircraft flight dynamics 7 Areas of use 7.1 Military 7.2 Civil 7.2.1 Commercial 7.2.2 General aviation 7.3 Experimental 7.4 Model 8 Aircraft manufacture 8.1 Manufacturers and types 8.2 Aircraft design 9 See also 9.1 Lists 9.2 Topics 10 References 11 External links History Main article: Aviation history See also: Timeline of aviation

The history of aircraft development divides broadly into five eras: Pioneers of flight First World War Inter-war sometimes called the Golden Age Second World War Postwar era also called the jet age Methods of lift Lighter than air aerostats

Aerostats use buoyancy 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 hydrogen or 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 kites.

Originally a balloon was any aerostat while the term airship was used for large powered aircraft designs usually fixed-wingcitation needed 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 outer framework and separate aerodynamic skin surrounding the gas bags were produced the Zeppelins 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 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. During the Second World War 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 and powered lift in the form of engine thrust. Aerodynamic lift involving wings is the most common with fixed-wing aircraft being kept in the air by the forward movement of wings and 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. To fly air must flow over the wing and generate lift. A flexible wing is a wing made of fabric or thin sheet material often stretched over a rigid frame. A kite 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 downwards. The initialism VTOL (vertical take off and landing) is applied to aircraft that can take off and land vertically. Most are rotorcraft. Others such as the Hawker Siddeley Harrier and F-35B take off and land vertically using powered lift and transfer to aerodynamic lift in steady flight. Similarly STOL stands for short take off and landing. Some VTOL aircraft often operate in a short take off/vertical landing mode known as STOVL. A pure rocket 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 which obtain aerodynamic lift at very high speed due to airflow over their bodies are a marginal case. Fixed-wing NASA test aircraft A size comparison of some of the largest fixed-wing aircraft. The Airbus A380-800 (largest airliner) the Boeing 747-8 the Antonov An-225 (aircraft with the greatest payload) and the Hughes H-4 "Spruce Goose" (aircraft with greatest wingspan). Airplanes or aeroplanes are technically called fixed-wing aircraft. The forerunner of the fixed-wing aircraft is the kite. 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 blowing over its wings to provide lift. Kites were the first kind of aircraft to fly and were invented in China 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 designed by Cayley carried out the first true manned controlled flight in 1853. Besides the method of propulsion fixed-wing aircraft are generally characterized by their wing configuration. The most important wing characteristics are: Number of wings Monoplane biplane etc. Wing support Braced or cantilever rigid or flexible. Wing planform including aspect ratio angle of sweep and any variations along the span (including the important class of delta wings). Location of the horizontal stabilizer if any. Dihedral angle positive zero or negative (anhedral). A variable geometry aircraft can change its wing configuration during flight. A flying wing has no fuselage though it may have small blisters or pods. The opposite of this is a lifting body which has no wings though it may have small stabilising and control surfaces. Most fixed-wing aircraft feature a tail unit or empennage incorporating vertical and often horizontal stabilising surfaces. Seaplanes are aircraft that land on water and they fit into two broad classes: Flying boats are supported on the water by their fuselage. A float plane's fuselage remains clear of the water at all times the aircraft being supported by two or more floats attached to the fuselage and/or wings. Some examples of both flying boats and float planes are amphibious being able to take off from and alight on both land and water. Some people consider wing-in-ground-effect vehicles to be fixed-wing aircraft others do not. These craft "fly" close to the surface of the ground or water. An example is the Russian ekranoplan (nicknamed the "Caspian Sea Monster"). Man-powered aircraft also rely on ground effect to remain airborne but this is only because they are so underpoweredthe airframe is theoretically capable of flying much higher. Rotorcraft Mil Mi-26 the world's largest production helicopter.2 Main article: Rotorcraft Rotorcraft or rotary-wing aircraft use a spinning rotor with aerofoil section blades (a rotary wing) to provide lift. Types include helicopters autogyros and various hybrids such as gyrodynes and compound rotorcraft. Helicopters have powered rotors. The rotor is driven (directly or indirectly) by an engine and pushes air downwards to create lift. By tilting the rotor forwards the downwards flow is tilted backwards producing thrust for forward flight. US-Recognition Manual (very likely copy of German drawing). Autogyros or gyroplanes have unpowered rotors with a separate power plant to provide thrust. The rotor is tilted backwards. As the autogyro moves forward air blows upwards across the rotor making it spin.(cf. Autorotation) This spinning dramatically increases the speed of airflow over the rotor to provide lift. Juan de la Cierva (a Spanish civil engineer) used the product name autogiro and Bensen used gyrocopter. Rotor kites such as the Focke Achgelis Fa 330 are unpowered autogyros which must be towed by a tether to give them forward ground speed or else be tether-anchored to a static anchor in a high-wind situation for kited flight. Gyrodynes are a form of helicopter where forward thrust is obtained from a separate propulsion device rather than from tilting the rotor. The definition of a 'gyrodyne' has changed over the years sometimes including equivalent autogyro designs. The Heliplane is a similar idea. Compound rotorcraft have wings which provide some or all of the lift in forward flight. Compound helicopters and compound autogyros have been built and some forms of gyroplane may be referred to as compound gyroplanes. They are nowadays classified as powered lift types and not as rotorcraft. Tiltrotor aircraft (such as the V-22 Osprey) have their rotors horizontal for vertical flight and pivot the rotors vertically like a propeller for forward flight. The Coleopter had a cylindrical wing forming a duct around the rotor. On the ground it sat on its tail and took off and landed vertically like a helicopter. The whole aircraft would then have tilted forward to fly as a propeller-driven fixed-wing aircraft using the duct as a wing (though this transition was never achieved in practice.) Some rotorcraft have reaction-powered rotors with gas jets at the tips but most have one or more lift rotors powered from engine-driven shafts. Other methods of lift X24B lifting body specialized glider A lifting body is the opposite of a flying wing. In this configuration the aircraft body is 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 were lifting bodies (though the shuttle itself is not) and some supersonic missiles obtain lift from the airflow over a tubular body. The flat bodies of recent jet fighters also produce lift as in the F-14 Tomcat's "pancake". Powered lift types rely on engine-derived lift for vertical takeoff and landing (VTOL). Most types transition to fixed-wing lift for horizontal flight. Classes of powered lift types include VTOL jet aircraft (such as the Harrier jump-jet) and tiltrotors (such as the V-22 Osprey) among others. A few examples rely entirely on engine thrust to provide lift throughout the whole flight. There are few practical applications. Experimental designs have been built for personal fan-lift hover platforms and jetpacks or for VTOL research (for example the flying bedstead). The Flettner airplane has a spinning cylinder in place of a wing relying on the Magnus effect to create lift. The FanWing is a recent innovation with some similarities to the Flettner rotor design. It uses a fixed wing with a cylindrical fan mounted spanwise just above. As the fan spins it creates an airflow backwards over the upper surface of the wing creating lift. The FanWing is (2010) in development in the United Kingdom. Propulsion Main article: air propulsion Unpowered Gliders Main article: Glider aircraft Heavier-than-air unpowered aircraft such as gliders (i.e. sailplanes) hang gliders and paragliders and other gliders usually do not employ propulsion once airborne. Take-off may be by launching forwards and downwards from a high location or by pulling into the air on a tow-line 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). Some 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 who many recognise as the first aeronautical engineer.3 Balloons Main article: Balloon (aircraft) Balloons 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. Kites Main article: kite Kites are aircraft4 that are tethered to the ground or other object (fixed or mobile) that maintains tension in the tether or kite line; they rely on virtual or real wind blowing over and under them to generate lift and drag. Kytoons are balloon kites that are shaped and tethered to obtain kiting deflections and can be lighter-than-air neutrally buoyant or heavier-than air. Powered Propeller Main article: Propeller (aircraft) A turboprop-engined DeHavilland Twin Otter adapted as a floatplane A propeller or airscrew comprises a set of small wing-like aerofoils set around a central hub which spins on an axis aligned in the direction of travel. Spinning the propeller creates aerodynamic lift or thrust in a forward direction. A tractor design mounts the propeller in front of the power source while a pusher design mounts it behind. Although the pusher design allows cleaner airflow over the wing tractor configuration is more common because it allows cleaner airflow to the propeller and provides a better weight distribution. A contra-prop arrangement has a second propeller close behind the first one on the same axis which rotates in the opposite direction. A variation on the propeller is to use many broad blades to create a fan. Such fans are traditionally surrounded by a ring-shaped fairing or duct as ducted fans. Many kinds of power plant have been used to drive propellers. The earliest designs used man power to give dirigible balloons some degree of control and go back to Jean-Pierre Blanchard in 1784. Attempts to achieve heavier-than-air man-powered flight did not succeed fully until Paul MacCready's Gossamer Condor in 1977. Gossamer Albatross a human-powered aircraft The first powered flight was made in a steam-powered dirigible by Henri Giffard in 1852. Attempts to marry a practical lightweight steam engine to a practical fixed-wing airframe did not succeed until much later by which time the internal combustion engine was already dominant. From the first controlled powered fixed-wing aircraft flight by the Wright brothers until World War II propellers turned by the internal combustion piston engine were virtually the only type of propulsion system in use. The piston engine is still used in the majority of smaller aircraft produced since it is efficient at the lower altitudes and slower speeds suited to propellers. Turbine engines need not be used as jets (see below) but may be geared to drive a propeller in the form of a turboprop. Modern helicopters also typically use turbine engines to power the rotor. Turbines provide more power for less weight than piston engines and are better suited to small-to-medium size aircraft or larger slow-flying types. Some turboprop designs (see below) mount the propeller directly on an engine turbine shaft and are called propfans. Since the 1940s propellers and propfans with swept tips or curved "scimitar-shaped" blades have been studied for use in high-speed applications so as to delay the onset of shockwaves in similar manner to wing sweepback where the blade tips approach the speed of sound. The Airbus A400M turboprop transport aircraft is expected to provide the first production example: note that it is not a propfan because the propellers are not mounted direct on the engine shaft but are driven through reduction gearing. Other less common power sources include: Electric motors often linked to solar panels to create a solar-powered aircraft. Rubber bands wound many times to store energy are mostly used for flying models. Jet Main article: Jet aircraft Airbreathing jet engines provide thrust by taking in air burning it with fuel in a combustion chamber and accelerating the exhaust rearwards so that it ejects at high speed. The reaction against this acceleration provides the engine thrust. A jet-engined Boeing 777 taking off Jet engines can provide much higher thrust than propellers and are naturally efficient at higher altitudes being able to operate above 40000 ft (12000 m). They are also much more fuel-efficient at normal flight speeds than rockets. Consequently nearly all high-speed and high-altitude aircraft use jet engines. The early turbojet and modern turbofan use a spinning turbine to create airflow for takeoff and to provide thrust. Many mostly in military aviation use afterburners which inject extra fuel into the exhaust. Use of a turbine is not absolutely necessary: other designs include the crude pulse jet high-speed ramjet and the still-experimental supersonic-combustion ramjet or scramjet. These designs require an existing airflow to work and cannot work when stationary so they must be launched by a catapult or rocket booster or dropped from a mother ship. The bypass turbofan engines of the Lockheed SR-71 were a hybrid design the aircraft took off and landed in jet turbine configuration and for high-speed flight the afterburner was lit and the turbine bypassed to create a ramjet. The motorjet was a very early design which used a piston engine in place of the combustion chamber similar to a turbocharged piston engine except that the thrust is derived from the turbine instead of the crankshaft. It was soon superseded by the turbojet and remained a curiosity. Helicopters HAL Dhruv a multi-role utility helicopter. Main article: Helicopter The rotor of a helicopter may like a propeller be powered by a variety of methods such as an internal-combustion engine or jet turbine. Tip jets fed by gases passing along hollow rotor blades from a centrally mounted engine have been experimented with. Attempts have even been made to mount engines directly on the rotor tips. Helicopters obtain forward propulsion by angling the rotor disc so that a proportion of its lift is directed forwards to provide thrust. Other methods of propulsion Rocket-powered aircraft have occasionally been experimented with and the Messerschmitt Komet fighter even saw action in the Second World War. Since then they have been restricted to rather specialised niches such as the Bell X-1 which broke the sound barrier or the North American X-15 which traveled up into space where no oxygen is available for combustion (rockets carry their own oxidant). Rockets have more often been used as a supplement to the main powerplant typically to assist takeoff of heavily loaded aircraft but also in a few experimental designs such as the Saunders-Roe SR.53 to provide a high-speed dash capability. The flapping-wing ornithopter is a category of its own. These designs may have potential but no practical device has been created beyond research prototypes simple toys and a model hawk used to freeze prey into stillness so that it can be captured. General construction Airframe Main article: Airframe Airframe diagram for a AgustaWestland AW101 helicopter The airframe of an aircraft is its mechanical structure5 which is typically considered to exclude the propulsion system. Airframe design is a field of engineering that combines aerodynamics materials technology and manufacturing methods to achieve balances of performance reliability and cost. Undercarriage Main article: 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. Typically wheels are used but skids floats or a combination of these and other elements can be deployed depending on the surface. Fuselage Main article: fuselage Fuselage of a Boeing 737 shown in brown The fuselage (from the French fusel "spindle-shaped") 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. The fuselage also serves to position control and stabilization surfaces in specific relationships to lifting surfaces required for aircraft stability and maneuverability. Wing configuration Main article: Wing configuration Many different styles and arrangements of wings have and are used on heavier-than-air aircraft and some lighter than air aircraft also have wings. The common wing configuration types have included monoplanes which has one wing each side biplane which have 4 wings. Wings also vary greatly in planform which is their shape viewed from above. Wings can be swept backwards or be delta wings and can have many other shapes. Aircraft engine Main article: aircraft engine An aircraft engine is a power source for an aircraft. Aircraft engines are almost always either lightweight piston engines or gas turbines. Powered aircraft have one or more engines. Propellant tanks Propellant (a chemical carried on board that is used to power the aircraft's flight) is usually a fuel and is kept in tanks around the vehicle. Most aircraft store the fuel predominantly in the wings but may have additional fuel tanks elsewhere. Flight control surfaces Main article: flight control surfaces Aircraft flight control surfaces allow a pilot to adjust and control the 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 stable flight. Empennage Main article: Empennage Empennage The empennage of a Boeing 747-200 Empennage ( /mpn/ or /mpnd/) is an aviation term used to describe the tail section of an aircraft.67 The empennage is also known as the tail or tail assembly; all three terms may be used interchangeably. The empennage gives stability to the aircraft and controls the flight dynamics of pitch and yaw.67 Flight deck Main article: cockpit Airbus A380 cockpit. Most Airbus cockpits are computerised glass cockpits featuring fly-by-wire technology. The control column has been replaced with an electronic sidestick. Swiss HB-IZX Saab 2000 cockpit Robin DR400/500 1936 De Havilland Hornet Moth 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. From the cockpit an aircraft is controlled on the ground and in the air. Cockpit as a term for the pilot's compartment in an aircraft first appeared in 1914. From about 1935 cockpit also came to be used informally to refer to the driver's seat of a car especially a high performance one and this is official terminology in Formula One. The term is most likely related to the sailing term for the coxswain's station in a Royal Navy ship and later the location of the ship's rudder controls.citation needed The cockpit of an aircraft contains flight instruments on an instrument panel and the controls which enable the pilot to fly the aircraft. In most airliners a door separates the cockpit from the passenger compartment. After the September 11 2001 terrorist attacks all major airlines fortified the cockpit against access by hijackers. On an airliner the cockpit is usually referred to as the flight deck. This term derives from its use by the RAF for the separate upper platform where the pilot and co-pilot sat in large flying boats. Cabin Main article: Aircraft cabin An aircraft cabin is the section of an aircraft in which any passengers travel often just called the cabin. At cruising altitudes if the surrounding atmosphere is too thin to breathe without an oxygen mask cabin pressurization adapts the cabin to atmospheric pressures. Performance of aircraft Flight envelope Main article: Flight envelope In aerodynamics the flight envelope or performance envelope of an aircraft refers to the capabilities of a design in terms of airspeed and load factor or altitude.89 The term is somewhat loosely applied and 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 rather dangerous. Flight envelope is one of a number of related terms that are all used in a similar fashion. It is perhaps the most common term because it is the oldest first being used in the early days of test flying. It is closely related to more modern terms known as extra power and a doghouse plot which are different ways of describing a flight envelope. Aircraft range Main article: range (aircraft) The Boeing 777-200LR is the longest-range commercial airliner capable of flights of more than halfway around the world. The maximal total range is the distance an aircraft can fly between takeoff and landing as limited by fuel capacity in powered aircraft or cross-country speed and environmental conditions in unpowered aircraft. Ferry range means the maximum range the 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. Combat range is the maximum range the aircraft can fly when carrying ordnance. Combat radius is a related measure based on the maximum distance a warplane can travel from its base of operations accomplish some objective and return to its original airfield with minimal reserves. The fuel time limit for powered aircraft is fixed by the fuel load and rate of consumption. When all fuel is consumed the engines stop and the aircraft will lose its propulsion. For unpowered aircraft the maximum flight time is variable limited by available daylight hours weather conditions and pilot endurance. The range can be seen as the cross-country ground speed multiplied by the maximum time in the air. The range equation will derived in this article for propeller and jet aircraft. Aircraft flight dynamics Main article: Flight dynamics (aircraft) 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 (quite different from their use as Tait-Bryan angles). Aerospace engineers develop control systems for a vehicle's orientation (attitude) about its center of mass. The control systems include actuators which exert forces in various directions and generate rotational forces or moments about the aerodynamic center of the aircraft and thus rotate the aircraft in pitch roll or yaw. For example a pitching moment 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. Roll pitch and yaw refer to rotations about the respective axes starting from a defined equilibrium state. The equilibrium roll angle is known as wings level or zero bank angle equivalent to a level heeling angle on a ship. Yaw is known as "heading". The equilibrium pitch angle in submarine and airship parlance is known as "trim" but in aircraft this usually refers to angle of attack rather than orientation. However common usage ignores this distinction between equilibrium and dynamic cases. The most common aeronautical convention defines the roll as acting about the longitudinal axis positive with the starboard (right) wing down. The yaw is about the vertical body axis positive with the nose to starboard. Pitch is about an axis perpendicular to the longitudinal plane of symmetry positive nose up.citation needed A fixed-wing aircraft increases or decreases the lift generated by the wings when it pitches nose up or down by increasing or decreasing the angle of attack (AOA). The roll angle is also known as bank angle on a fixed-wing aircraft which usually "banks" to change the horizontal direction of flight. An aircraft is usually streamlined from nose to tail to reduce drag making it typically advantageous to keep the sideslip angle near zero though there are instances when an aircraft may be deliberately "sideslipped" for example a slip in a fixed-wing aircraft.citation needed Areas of use The major distinction in aircraft types is between military aircraft which includes not just combat types but many types of supporting aircraft and civil aircraft which include all non-military types. Saab Gripen a Swedish multi-role fighter aircraft. Military Main article: 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.10 Military aircraft can be either combat or non-combat: Combat aircraft are aircraft designed to destroy enemy equipment using its own armament.10 Non-Combat aircraft are aircraft not designed for combat as their primary function but may carry weapons for self-defense. Mainly operating in support roles. Combat aircraft divide broadly into fighters and bombers with several in-between types such as fighter-bombers and ground-attack aircraft (including attack helicopters). Other supporting roles are carried out by specialist patrol search and rescue reconnaissance observation transport training and tanker aircraft among others. Many civil aircraft both fixed-wing and rotary have been produced in separate models for military use such as the civil Douglas DC-3 airliner which became the military C-47/C-53/R4D transport in the U.S. military and the "Dakota" in the UK and the Commonwealth. Even the small fabric-covered two-seater Piper J3 Cub had a military version the L-4 liaison observation and trainer aircraft. Gliders and balloons have also been used as military aircraft; for example balloons were used for observation during the American Civil War and World War I and military gliders were used during World War II to land troops. The Premium Class cabin of Jet Airways Boeing 777. Eurocopter EC 145 of the Rega air rescue service. Civil Main article: Civil aviation Civil aircraft divide into commercial and general types however there are some overlaps. Commercial Main article: Commercial aviation Commercial aircraft include types designed for scheduled and charter airline flights carrying both passengers and cargo. The larger passenger-carrying types are often referred to as airliners the largest of which are wide-body aircraft. Some of the smaller types are also used in general aviation and some of the larger types are used as VIP aircraft. General aviation Main article: General aviation General aviation is a catch-all covering other kinds of private and commercial use and involving a wide range of aircraft types such as business jets (bizjets) trainers homebuilt aerobatic types racers gliders warbirds firefighters medical transports and cargo transports to name a few. The vast majority of aircraft today are general aviation types. Within general aviation there is a further distinction between private aviation (where the pilot is not paid for time or expenses) and commercial aviation (where the pilot is paid by a client or employer). The aircraft used in private aviation are usually light passenger business or recreational types and are usually owned or rented by the pilot. The same types may also be used for a wide range of commercial tasks such as flight training pipeline surveying passenger and freight transport policing crop dusting and medical evacuations. However the larger more complex aircraft are more likely to be found in the commercial sector. For example piston-powered propeller aircraft (single-engine or twin-engine) are common for both private and commercial general aviation but for aircraft such as turboprops like the Beechcraft King Air and helicopters like the Bell JetRanger there are fewer private owners than commercial owners. Conventional business jets are most often flown by paid pilots whereas the new generation of smaller jets are being produced for private pilots. Experimental Main article: Experimental aircraft Experimental aircraft are one-off specials built to explore some aspect of aircraft design and with no other useful purpose. The Bell X-1 rocket plane which first broke the sound barrier in level flight is a famous example. A model aircraft weighing six grams. Boeing B-17E in flight. The Allies of World War II lost 160000 airmen and 33700 planes during the air war over Europe.11 The formal designation of "experimental aircraft" also includes other types which are "not certified for commercial applications" including one-off modifications of existing aircraft such as the modified Boeing 747 which NASA uses to ferry the space shuttle from landing site to launch site and aircraft homebuilt by amateurs for their own personal use. Model Main article: Model aircraft A model aircraft is a small unmanned type made to fly for fun for static display for aerodynamic research (cf Reynolds number) or for other purposes. A scale model is a replica of some larger design. Aircraft manufacture Manufacturers and types Within any general category aircraft are usually listed according to manufacturer and production type. Also see: List of aircraft Aircraft design Main article: Aircraft design process See also Lists List of aircraft by category List of Airliners by Historical Epoch List of civil aircraft List of early flying machines List of helicopter models List of large aircraft List of military aircraft List of Regional Airliners List of World War II jet aircraft Aviation portal List of aircraft by date and usage category List of aircraft engines List of altitude records reached by different aircraft types List of aviation aerospace and aeronautical terms Topics Air safety Airmail Airmails of the United States Air transports of Heads of State Aerial refuelling Aircraft design process Aircraft axis Aircraft carrier Aircraft spotting Airline call signs Aviation Balloon (aircraft) Cabin pressurization Contrail First flying machine   Flight controls Flight instruments Flight tracking Flight planning Flying car/roadable aircraft General aviation in Europe Gliding Loss of structural integrity on an aircraft Military aircraft Model rocket Noise pollution Personal air vehicle Powered parachute Powered paragliding   Pressure suit Rocket Rocket engine Rocket propellant Spacecraft Spaceflight Spaceplane Space Shuttle program Stealth aircraft Steam aircraft Surveillance aircraft Wide-body aircraft References dictionary.com definition of aircraft Mil Mi-26 Halo Dee Richard (2007). The Man who Discovered Flight: George Cayley and the First Airplane. Toronto: McClelland and Stewart. ISBN 978-0-7710-2971-4.  NASA's Beginners Guide to Aeronautics Ed Rouen (2005). Airplane Names. San Diego Aerospace Museum. http://www.marchfield.org/rouen01.html.  Names and dates of more than 2800 aircraft models produced since 1900. a b Crane Dale: Dictionary of Aeronautical Terms third edition page 194. Aviation Supplies & Academics 1997. ISBN 1-56027-287-2 a b Aviation Publishers Co. Limited From the Ground Up page 10 (27th revised edition) ISBN 0-9690054-9-0 23.333 Flight envelope Flight envelope - diagram a b Gunston 1986 p. 274 Kenneth K. Hatfield (2003). "Heartland heroes: remembering World War II.". p.91. Gunston Bill (1986). Jane's Aerospace Dictionary. London England: Jane's Publishing Company Limited. ISBN 0-7106-0365-7.  External links Look up aircraft in Wiktionary the free dictionary. Wikimedia Commons has media related to: Aircraft History History of Aviation in Australia - State Library of NSW Prehistory of Powered Flight The Channel Crossing The Evolution of Modern Aircraft (NASA) Virtual Museum Smithsonian Air and Space Museum Online collection with a particular focus on history of aircraft and spacecraft New Scientist's History of Aviation Amazing Early Flying Machines slideshow by Life magazine Aircraft Types Information Airliners.net Aviation Dictionary Free aviation terms phrases and jargons New Scientist's Aviation page Aircraft Components Technology v d eAircraft types Military aircraft ASW  Attack  AWACS  Bomber  Command and control  Cruise missile  Electronic warfare  Fighter  Patrol  Reconnaissance  Rescue  Tankers  Trainers  Transports  Utility Civil aircraft Agricultural  Airliners  Business  Cargo aircraft  Mailplanes  Sailplanes  Sport aircraft  Trainers  Ultralights  Utility  Trijets  Wide-body aircraft Miscellaneous Experimental aircraft  Seaplanes  Special-purpose v d eLists of aircraft By name pre 1914  0-A  B  C  D  E-F  G-H  IK  L  M  NO  P-Q  R  S  T  U-Z  gliders  HPA By category Civil aircraft By type Fuselage characteristics Double-deck  Narrow-body  Wide-body Size characteristics Commercial civilian passenger fixed-wing aircraft airliners with more than 9 seats (After 2005)  "Boeing 747 Jumbo Jet" variants  Jumbo jets  Other "Jumbo jets"  Maximum Takeoff Weight Manufacturer Airbus airliners  Boeing Airliners  McDonnell Douglas Airliners Models Lockheed Constellation Number of engines Trijets  Trimotors  Twinjets  Aircraft engine position number Range Regional airliners  Short-haul civilian passenger aircraft post war  Short-haul jet airliners Aircraft uses Airliners  Light Transport  Regional airliner  Regional jet Unique features Flying wing  Gliders  Large a/c  Prone pilot  Seaplanes and amphibious   HPA Exploratory Early flying machines  Experimental  Rocket planes  X-planes Rotor powered Autogyros  Rotorcraft  Tiltrotors Executive or private transport Business jets  Light-sport aircraft  Personal aircraft  Roadable aircraft  VLJs Rigid airships Zeppelins By country of origin Sweden By manufacturer de Havilland  Lockheed  Parseval  Santos-Dumont  Schtte-Lanz By user Imperial Airways Other By date and usage  By tail number  Most produced Military aircraft By nation Argentina  Australia: RAAF - RAN  Canada: RCAF - RCN - AIRCOM  China  Denmark  Finland  France  Germany: WWI I designations - RLM designations - WWII aircraft  India  Iran  Ireland  Israel  Japan: designation systems  New Zealand  Norway  Pakistan  South Africa  Soviet Union and the CIS: designation systems  Sweden  UK: designation systems - RAF - FAA - Army Air Corps  United States: designation systems - Active United States military aircraft - Airships of the United States Navy By type Fighter (Attack)  Bomber  Carrier-based By conflict WWII gliders  WWII helicopters  WWII jets  Undersea-carried WWII v d eAircraft components and systems Airframe structure Cabane strut  Canopy  Cruciform tail  Empennage  Fairing  Fabric covering  Flying wires  Former  Fuselage  Interplane strut  Horizontal stabilizer  Jury strut  Leading edge  Lift strut  Longeron  Nacelle  Rear pressure bulkhead  Rib  Spar  Stabilizer  Stressed skin  Strut  Tailplane  Trailing edge  T-tail  Twin tail  Vertical stabilizer  V-tail  Wing root  Wing tip Flight controls Aileron  Airbrake  Artificial feel  Autopilot  Canard  Centre stick  Deceleron  Dive brake  Elevator  Elevon  Electro-hydrostatic actuator  Flaperon  Flight control modes  Fly-by-wire  Gust lock  Rudder  Servo tab  Side-stick  Spoiler  Spoileron  Stabilator  Stick pusher  Stick shaker  Trim tab  Yaw damper  Wing warping  Yoke Aerodynamic and high-lift devices Active Aeroelastic Wing  Adaptive Compliant Wing  Blown flap  Channel wing  Dog-tooth  Flap  Gouge flap  Gurney flap  Krueger flaps  Leading edge cuff  LEX  Slats  Slot  Stall strips  Strake  Variable-sweep wing  Vortex generator  Wing fence  Winglet Avionic and flight instrument systems ACAS  Air data computer  Airspeed indicator  Altimeter  Annunciator panel  Attitude indicator  Compass  Course Deviation Indicator  EFIS  EICAS  Flight data recorder  Flight management system  Glass cockpit  GPS  Heading indicator  Horizontal situation indicator  INAS  TCAS  Transponder  Turn and bank indicator  Pitot-static system  Radar altimeter  Vertical Speed Indicator  Yaw string Propulsion controls devices and fuel systems Autothrottle  Drop tank  FADEC  Fuel tank  Gascolator  Inlet cone  Intake ramp  NACA cowling  Self-sealing fuel tank  Throttle  Thrust lever  Thrust reversal  Townend ring  Wet wing Landing and arresting gear Autobrake  Conventional landing gear  Arrestor hook  Drogue parachute  Landing gear extender  Tricycle gear  Tundra tire  Undercarriage Escape systems Ejection seat  Escape crew capsule Other systems Aircraft lavatory  Auxiliary power unit  Bleed air system  Deicing boot  Emergency oxygen system  Environmental Control System  Hydraulic system  Ice protection system  Landing lights  Navigation light  Passenger service unit  Ram air turbine