An aircraft is a vehicle that is able to
fly by gaining support from the
air
The atmosphere of Earth is the layer of gases, known collectively as air, retained by Earth's gravity that surrounds the planet and forms its planetary atmosphere. The atmosphere of Earth protects life on Earth by creating pressure allowing f ...
. It counters the force of gravity by using either
static lift or by using the
dynamic lift
A fluid flowing around an object exerts a force on it. Lift is the Vector (geometric)#Vector components, component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag (physics), drag force, which is th ...
of an
airfoil, or in a few cases the
downward thrust from
jet engines. Common examples of aircraft include
airplane
An airplane or aeroplane (informally plane) is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, Propeller (aircraft), propeller, or rocket engine. Airplanes come in a variety of sizes, shapes, and wing configurat ...
s,
helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...
s,
airship
An airship or dirigible balloon is a type of aerostat or lighter-than-air aircraft that can navigate through the air under its own power. Aerostats gain their lift from a lifting gas that is less dense than the surrounding air.
In early ...
s (including
blimp
A blimp, or non-rigid airship, is an airship (dirigible) without an internal structural framework or a keel. Unlike semi-rigid and rigid airships (e.g. Zeppelins), blimps rely on the pressure of the lifting gas (usually helium, rather than hy ...
s),
gliders,
paramotors
Powered paragliding, also known as paramotoring or PPG, is a form of ultralight aviation where the pilot wears a back-pack motor (a paramotor) which provides enough thrust to take off using a paraglider. It can be launched in still air, and on ...
, and
hot air balloon
A hot air balloon is a lighter-than-air aircraft consisting of a bag, called an envelope, which contains heated air. Suspended beneath is a gondola or wicker basket (in some long-distance or high-altitude balloons, a capsule), which carries ...
s.
The human activity that surrounds aircraft is called ''
aviation
Aviation includes the activities surrounding mechanical flight and the aircraft industry. ''Aircraft'' includes fixed-wing and rotary-wing types, morphable wings, wing-less lifting bodies, as well as lighter-than-air craft such as hot a ...
''. The science of aviation, including designing and building aircraft, is called ''
aeronautics.''
Crewed aircraft are flown by an onboard
pilot
An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its directional flight controls. Some other aircrew members, such as navigators or flight engineers, are also considered aviators, because they a ...
, but
unmanned aerial vehicle
An unmanned aerial vehicle (UAV), commonly known as a drone, is an aircraft without any human pilot, crew, or passengers on board. UAVs are a component of an unmanned aircraft system (UAS), which includes adding a ground-based controll ...
s may be remotely controlled or self-controlled by onboard
computers. Aircraft may be classified by different criteria, such as lift type,
aircraft propulsion
A powered aircraft is an aircraft that uses onboard propulsion with mechanical power generated by an aircraft engine of some kind.
Aircraft propulsion nearly always uses either a type of propeller, or a form of jet propulsion. Other potential ...
, usage and others.
History
Flying model craft and stories of manned
flight
Flight or flying is the process by which an object moves through a space without contacting any planetary surface, either within an atmosphere (i.e. air flight or aviation) or through the vacuum of outer space (i.e. spaceflight). This can be a ...
go back many centuries; however, the first manned ascent — and safe descent — in modern times took place by larger hot-air balloons developed in the 18th century. Each of the two
World Wars
A world war is an international conflict which involves all or most of the world's major powers. Conventionally, the term is reserved for two major international conflicts that occurred during the first half of the 20th century, World WarI (1914 ...
led to great technical advances. Consequently, the history of aircraft can be divided into five eras:
*
Pioneers of flight, from the earliest experiments to 1914.
*
First World War
World War I (28 July 1914 11 November 1918), often abbreviated as WWI, was one of the deadliest global conflicts in history. Belligerents included much of Europe, the Russian Empire, the United States, and the Ottoman Empire, with fightin ...
, 1914 to 1918.
*
Aviation between the World Wars, 1918 to 1939.
*
Second World War
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...
, 1939 to 1945.
*
Postwar era
In Western world, Western usage, the phrase post-war era (or postwar era) usually refers to the time since the end of World War II. More broadly, a post-war period (or postwar period) is the interval immediately following the end of a war. A po ...
, also called the
Jet Age
The Jet Age is a period in the history of aviation defined by the advent of aircraft powered by jet turbine engines, and by the social change this brought about.
Jet airliners were able to fly much higher, faster, and farther than older pisto ...
, 1945 to the present day.
Methods of lift
Lighter than air – aerostats
Aerostats use
buoyancy
Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the ...
to float in the air in much the same way that ships float on the water. They are characterized by one or more large cells or canopies, filled with a relatively low-density gas such as
helium
Helium (from el, ἥλιος, helios, lit=sun) is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas and the first in the noble gas group in the periodic table. ...
,
hydrogen
Hydrogen is the chemical element with the symbol H and atomic number 1. Hydrogen is the lightest element. At standard conditions hydrogen is a gas of diatomic molecules having the formula . It is colorless, odorless, tasteless, non-toxic ...
, or
hot air
''Hot Air'' is a conservative American political blog. It is written by the pseudonymous Allahpundit, Ed Morrissey, John Sexton, and Jazz Shaw.
Hot Air was founded by Michelle Malkin, a conservative author and blogger, in 2006, taking over '' ...
, 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 lantern
A sky lantern (), also known as Kǒngmíng lantern (), or Chinese lantern, is a small hot air balloon made of paper, with an opening at the bottom where a small fire is suspended.
In Asia and elsewhere around the world, sky lanterns have bee ...
s, were first invented in ancient China prior to the 3rd century BC and used primarily in cultural celebrations, and were only the second type of aircraft to fly, the first being
kite
A kite is a tethered heavier-than-air or lighter-than-air craft with wing surfaces that react against the air to create lift and drag forces. A kite consists of wings, tethers and anchors. Kites often have a bridle and tail to guide the fac ...
s, which were first invented in ancient China over two thousand years ago. (See
Han Dynasty
The Han dynasty (, ; ) was an imperial dynasty of China (202 BC – 9 AD, 25–220 AD), established by Liu Bang (Emperor Gao) and ruled by the House of Liu. The dynasty was preceded by the short-lived Qin dynasty (221–207 BC) and a warr ...
)
A
balloon
A balloon is a flexible bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, and air. For special tasks, balloons can be filled with smoke, liquid water, granular media (e.g. sand, flour or rice), or light so ...
was originally any aerostat, while the term
airship
An airship or dirigible balloon is a type of aerostat or lighter-than-air aircraft that can navigate through the air under its own power. Aerostats gain their lift from a lifting gas that is less dense than the surrounding air.
In early ...
was used for large, powered aircraft designs — usually fixed-wing. In 1919,
Frederick Handley Page
Sir Frederick Handley Page, CBE, FRAeS (15 November 1885 – 21 April 1962) was an English industrialist who was a pioneer in the aircraft industry and became known as the father of the heavy bomber.
His company Handley Page Limited was ...
was reported as referring to "ships of the air," with smaller passenger types as "Air yachts." In the 1930s, large intercontinental flying boats were also sometimes referred to as "ships of the air" or "flying-ships". — 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
Zeppelin
A Zeppelin is a type of rigid airship named after the German inventor Count Ferdinand von Zeppelin () who pioneered rigid airship development at the beginning of the 20th century. Zeppelin's notions were first formulated in 1874Eckener 1938, pp ...
s being the largest and most famous. There were still no fixed-wing aircraft or non-rigid balloons large enough to be called airships, so "airship" came to be synonymous with these aircraft. Then several accidents, such as the
Hindenburg disaster
The ''Hindenburg'' disaster was an airship accident that occurred on May 6, 1937, in Manchester Township, New Jersey, United States. The German passenger airship LZ 129 ''Hindenburg'' caught fire and was destroyed during its attemp ...
in 1937, led to the demise of these airships. Nowadays a "balloon" is an unpowered aerostat and 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
Aerodynamics, from grc, ἀήρ ''aero'' (air) + grc, δυναμική (dynamics), is the study of the motion of air, particularly when affected by a solid object, such as an airplane wing. It involves topics covered in the field of fluid dyn ...
gasbag with stabilizing fins at the back. These soon became known as ''
blimp
A blimp, or non-rigid airship, is an airship (dirigible) without an internal structural framework or a keel. Unlike semi-rigid and rigid airships (e.g. Zeppelins), blimps rely on the pressure of the lifting gas (usually helium, rather than hy ...
s''. During
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
, this shape was widely adopted for
tethered balloons
A tether is a cord, fixture, or flexible attachment that characteristically anchors something movable to something fixed; it also maybe used to connect two movable objects, such as an item being towed by its tow.
Applications for tethers includ ...
; 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, such as
airplane
An airplane or aeroplane (informally plane) is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, Propeller (aircraft), propeller, or rocket engine. Airplanes come in a variety of sizes, shapes, and wing configurat ...
s, 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. There are two ways to produce dynamic upthrust —
aerodynamic lift
A fluid flowing around an object exerts a force on it. Lift is the component of this force that is perpendicular to the oncoming flow direction. It contrasts with the drag force, which is the component of the force parallel to the flow direc ...
, and
powered lift
A powered lift aircraft takes off and lands vertically under engine power but uses a fixed wing for horizontal flight. Like helicopters, these aircraft do not need a long runway to take off and land, but they have a speed and performance similar ...
in the form of engine thrust.
Aerodynamic lift involving
wing
A wing is a type of fin that produces lift while moving through air or some other fluid. Accordingly, wings have streamlined cross-sections that are subject to aerodynamic forces and act as airfoils. A wing's aerodynamic efficiency is e ...
s is the most common, with
fixed-wing aircraft being kept in the air by the forward movement of wings, and
rotorcraft
A rotorcraft or rotary-wing aircraft is a heavier-than-air aircraft with rotary wings or rotor blades, which generate lift by rotating around a vertical mast. Several rotor blades mounted on a single mast are referred to as a rotor. The Internat ...
by spinning wing-shaped
rotors sometimes called "rotary wings." A wing is a flat, horizontal surface, usually shaped in cross-section as an
aerofoil
An airfoil (American English) or aerofoil (British English) is the cross-sectional shape of an object whose motion through a gas is capable of generating significant lift, such as a wing, a sail, or the blades of propeller, rotor, or turbine. ...
. To fly, air must flow over the wing and generate
lift
Lift or LIFT may refer to:
Physical devices
* Elevator, or lift, a device used for raising and lowering people or goods
** Paternoster lift, a type of lift using a continuous chain of cars which do not stop
** Patient lift, or Hoyer lift, mobil ...
. A ''flexible wing'' is a wing made of fabric or thin sheet material, often stretched over a rigid frame. A ''
kite
A kite is a tethered heavier-than-air or lighter-than-air craft with wing surfaces that react against the air to create lift and drag forces. A kite consists of wings, tethers and anchors. Kites often have a bridle and tail to guide the fac ...
'' 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 downward.
V/STOL
A vertical and/or short take-off and landing (V/STOL) aircraft is an airplane able to take-off or land vertically or on short runways. Vertical takeoff and landing (VTOL) aircraft are a subset of V/STOL craft that do not require runways at a ...
aircraft, such as the
Harrier jump jet
The Harrier, informally referred to as the Harrier jump jet, is a family of jet-powered attack aircraft capable of vertical/short takeoff and landing operations (V/STOL). Named after a bird of prey, it was originally developed by British ma ...
and
Lockheed Martin F-35B take off and land vertically using powered lift and transfer to aerodynamic lift in steady flight.
A pure
rocket
A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...
is not usually regarded as an aerodyne because it does not depend on the air for its lift (and can even fly into space); however, many aerodynamic lift vehicles have been powered or assisted by rocket motors. Rocket-powered missiles that obtain aerodynamic lift at very high speed due to airflow over their bodies are a marginal case.
Fixed-wing
The forerunner of the fixed-wing aircraft is the
kite
A kite is a tethered heavier-than-air or lighter-than-air craft with wing surfaces that react against the air to create lift and drag forces. A kite consists of wings, tethers and anchors. Kites often have a bridle and tail to guide the fac ...
. Whereas a fixed-wing aircraft relies on its forward speed to create airflow over the wings, a kite is tethered to the ground and relies on the
wind
Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few ho ...
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 tunnel
Wind tunnels are large tubes with air blowing through them which are used to replicate the interaction between air and an object flying through the air or moving along the ground. Researchers use wind tunnels to learn more about how an aircraft ...
s, and computer modelling programs became available.
The first heavier-than-air craft capable of controlled free-flight were
gliders. A glider designed by
George Cayley carried out the first true manned, controlled flight in 1853.
The practical, powered, fixed-wing aircraft (the
airplane
An airplane or aeroplane (informally plane) is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, Propeller (aircraft), propeller, or rocket engine. Airplanes come in a variety of sizes, shapes, and wing configurat ...
or aeroplane) was invented by
Wilbur and Orville Wright. Besides the method of
propulsion
Propulsion is the generation of force by any combination of pushing or pulling to modify the translational motion of an object, which is typically a rigid body (or an articulated rigid body) but may also concern a fluid. The term is derived f ...
, fixed-wing aircraft are in general characterized by their
wing configuration
The wing configuration of a fixed-wing aircraft (including both glider (aircraft), gliders and powered aeroplanes) is its arrangement of lifting and related surfaces.
Aircraft designs are often classified by their wing configuration. For examp ...
. The most important wing characteristics are:
* Number of wings —
monoplane
A monoplane is a fixed-wing aircraft configuration with a single mainplane, in contrast to a biplane or other types of multiplanes, which have multiple planes.
A monoplane has inherently the highest efficiency and lowest drag of any wing con ...
,
biplane, etc.
* Wing support — Braced or cantilever, rigid, or flexible.
* Wing planform — including
aspect ratio, angle of
sweep
Sweep or swept may refer to:
Cleaning
* Sweep, the action of using a brush to clean
* Chimney sweep, a worker who clears ash and soot from chimneys
* Street sweeper, a person's occupation, or a machine that cleans streets
* Swept quartz, a cleani ...
, and any variations along the span (including the important class of
delta wings).
* Location of the horizontal stabilizer, if any.
*
Dihedral angle
A dihedral angle is the angle between two intersecting planes or half-planes. In chemistry, it is the clockwise angle between half-planes through two sets of three atoms, having two atoms in common. In solid geometry, it is defined as the un ...
— 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
A lifting body is a fixed-wing aircraft or spacecraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage ...
'', which has no wings, though it may have small stabilizing and control surfaces.
Wing-in-ground-effect
A ground-effect vehicle (GEV), also called a wing-in-ground-effect (WIG), ground-effect craft, wingship, flarecraft or ekranoplan (russian: экранопла́н – "screenglider"), is a vehicle that is able to move over the surface by gainin ...
vehicles are generally not considered aircraft. They "fly" efficiently close to the surface of the ground or water, like conventional aircraft during takeoff. An example is the Russian ekranoplan nicknamed the "
Caspian Sea Monster
The KM (Korabl Maket) (Russian: Корабль-Макет, literally "Ship-maquette" or "Model-Ship"), known colloquially as the Caspian Sea Monster, was an experimental ground effect vehicle developed in the Soviet Union in the 1960s by the C ...
".
Man-powered aircraft also rely on
ground effect to remain airborne with minimal pilot power, but this is only because they are so underpowered—in fact, the airframe is capable of flying higher.
Rotorcraft
Rotorcraft, or rotary-wing aircraft, use a spinning
rotor
Rotor may refer to:
Science and technology
Engineering
* Rotor (electric), the non-stationary part of an alternator or electric motor, operating with a stationary element so called the stator
*Helicopter rotor, the rotary wing(s) of a rotorcraft ...
with aerofoil cross-section blades (a ''rotary wing'') to provide lift. Types include
helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...
s,
autogyro
An autogyro (from Greek and , "self-turning"), also known as a ''gyroplane'', is a type of rotorcraft that uses an unpowered rotor in free autorotation to develop lift. Forward thrust is provided independently, by an engine-driven propeller. Whi ...
s, and various hybrids such as
gyrodyne
A gyrodyne is a type of VTOL aircraft with a helicopter rotor-like system that is driven by its engine for takeoff and landing only, and includes one or more conventional propeller or jet engines to provide forward thrust during cruising flig ...
s and compound rotorcraft.
''
Helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...
s'' have a rotor turned by an engine-driven shaft. The rotor pushes air downward to create lift. By tilting the rotor forward, the downward flow is tilted backward, producing thrust for forward flight. Some helicopters have more than one rotor and a few have rotors turned by gas jets at the tips. Some have a
tail rotor
The tail rotor is a smaller rotor mounted vertically or near-vertically at the tail of a traditional single-rotor helicopter, where it rotates to generate a propeller-like horizontal thrust in the same direction as the main rotor's rotation. Th ...
to counteract the rotation of the main rotor, and to aid directional control.
''
Autogyro
An autogyro (from Greek and , "self-turning"), also known as a ''gyroplane'', is a type of rotorcraft that uses an unpowered rotor in free autorotation to develop lift. Forward thrust is provided independently, by an engine-driven propeller. Whi ...
s'' have unpowered rotors, with a separate power plant to provide thrust. The rotor is tilted backward. As the autogyro moves forward, air blows upward across the rotor, making it spin. This spinning increases the speed of airflow over the rotor, to provide lift.
Rotor kite
A rotor kite or gyrokite is an unpowered, rotary-wing aircraft. Like an autogyro or helicopter, it relies on lift created by one or more sets of rotors in order to fly. Unlike a helicopter, gyrokites and rotor kites do not have an engine power ...
s are unpowered autogyros, which are towed to give them forward speed or tethered to a static anchor in high-wind for kited flight.
''
Cyclogyro
The cyclogyro, or cyclocopter, is an aircraft configuration that uses a horizontal-axis cyclorotor as a rotor wing to provide lift and sometimes also propulsion and control. In principle, the cyclogyro is capable of vertical take off and land ...
s'' rotate their wings about a horizontal axis.
''Compound rotorcraft'' have wings that provide some or all of the lift in forward flight. They are nowadays classified as ''
powered lift
A powered lift aircraft takes off and lands vertically under engine power but uses a fixed wing for horizontal flight. Like helicopters, these aircraft do not need a long runway to take off and land, but they have a speed and performance similar ...
'' types and not as rotorcraft. ''
Tiltrotor
A tiltrotor is an aircraft which generates lift and propulsion by way of one or more powered rotors (sometimes called ''proprotors'') mounted on rotating shafts or nacelles usually at the ends of a fixed wing. Almost all tiltrotors use a trans ...
'' aircraft (such as the
Bell Boeing V-22 Osprey
The Bell Boeing V-22 Osprey is an American multi-mission, tiltrotor military aircraft with both vertical takeoff and landing (VTOL) and short takeoff and landing (STOL) capabilities. It is designed to combine the functionality of a conventio ...
),
tiltwing
A tiltwing aircraft features a wing that is horizontal for conventional forward flight and rotates up for vertical takeoff and landing. It is similar to the tiltrotor design where only the propeller and engine rotate. Tiltwing aircraft are typical ...
,
tail-sitter
A tail-sitter, or tailsitter, is a type of VTOL aircraft that takes off and lands on its tail, then tilts horizontally for forward flight.
Originating in the 1920s with the inventor Nikola Tesla, the first aircraft to adopt a tail-sitter configur ...
, and
coleopter
A coleopter is a type of VTOL aircraft design that uses a ducted fan as the primary fuselage of the entire aircraft. Generally they appear to be a large barrel-like extension at the rear, with a small cockpit area suspended above it. Coleopters ...
aircraft have their rotors/
propellers
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...
horizontal for vertical flight and vertical for forward flight.
Other methods of lift
* A ''
lifting body
A lifting body is a fixed-wing aircraft or spacecraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage ...
'' is an aircraft body shaped to produce lift. If there are any wings, they are too small to provide significant lift and are used only for stability and control. Lifting bodies are not efficient: they suffer from high drag, and must also travel at high speed to generate enough lift to fly. Many of the research prototypes, such as the
Martin Marietta X-24
The Martin Marietta X-24 was an American experimental aircraft developed from a joint United States Air Force-NASA program named PILOT (1963–1975). It was designed and built to test lifting body concepts, experimenting with the concept of u ...
, which led up to the
Space Shuttle
The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program ...
, were lifting bodies, though the Space Shuttle is not, and some
supersonic missile
In military terminology, a missile is a guided airborne ranged weapon capable of self-propelled flight usually by a jet engine or rocket motor. Missiles are thus also called guided missiles or guided rockets (when a previously unguided rocke ...
s obtain lift from the airflow over a tubular body.
* ''
Powered lift
A powered lift aircraft takes off and lands vertically under engine power but uses a fixed wing for horizontal flight. Like helicopters, these aircraft do not need a long runway to take off and land, but they have a speed and performance similar ...
'' types rely on engine-derived lift for vertical takeoff and landing (
VTOL
A vertical take-off and landing (VTOL) aircraft is one that can take off and land vertically without relying on a runway. This classification can include a variety of types of aircraft including helicopters as well as thrust-vectoring fixed-wi ...
). Most types transition to fixed-wing lift for horizontal flight. Classes of powered lift types include
VTOL
A vertical take-off and landing (VTOL) aircraft is one that can take off and land vertically without relying on a runway. This classification can include a variety of types of aircraft including helicopters as well as thrust-vectoring fixed-wi ...
jet aircraft (such as the
Harrier jump jet
The Harrier, informally referred to as the Harrier jump jet, is a family of jet-powered attack aircraft capable of vertical/short takeoff and landing operations (V/STOL). Named after a bird of prey, it was originally developed by British ma ...
) and
tiltrotor
A tiltrotor is an aircraft which generates lift and propulsion by way of one or more powered rotors (sometimes called ''proprotors'') mounted on rotating shafts or nacelles usually at the ends of a fixed wing. Almost all tiltrotors use a trans ...
s, such as the
Bell Boeing V-22 Osprey
The Bell Boeing V-22 Osprey is an American multi-mission, tiltrotor military aircraft with both vertical takeoff and landing (VTOL) and short takeoff and landing (STOL) capabilities. It is designed to combine the functionality of a conventio ...
, among others. A few experimental designs rely entirely on engine thrust to provide lift throughout the whole flight, including personal fan-lift hover platforms and jetpacks.
VTOL
A vertical take-off and landing (VTOL) aircraft is one that can take off and land vertically without relying on a runway. This classification can include a variety of types of aircraft including helicopters as well as thrust-vectoring fixed-wi ...
research designs include the
Rolls-Royce Thrust Measuring Rig
The Rolls-Royce Thrust Measuring Rig (TMR), was a pioneering vertical take-off and landing (VTOL) aircraft developed by Rolls-Royce in the 1950s. It has the distinction of being "the first jet-lift aircraft to fly anywhere in the world".
The ...
.
* The ''
Flettner airplane
A Flettner airplane is a type of rotor airplane which uses a Flettner rotor to provide lift. The rotor comprises a spinning cylinder with circular end plates and, in an aircraft, spins about a spanwise horizontal axis. When the aircraft moves ...
'' uses a rotating cylinder in place of a fixed wing, obtaining lift from the
Magnus effect
The Magnus effect is an observable phenomenon commonly associated with a spinning object moving through a fluid. The path of the spinning object is deflected in a manner not present when the object is not spinning. The deflection can be expl ...
.
* The ''
ornithopter
An ornithopter (from Greek ''ornis, ornith-'' "bird" and ''pteron'' "wing") is an aircraft that flies by flapping its wings. Designers sought to imitate the flapping-wing flight of birds, bats, and insects. Though machines may differ in form, ...
'' obtains thrust by flapping its wings.
Size and speed extremes
Size
The smallest aircraft are toys/recreational items, and
nano aircraft.
The largest aircraft by dimensions and volume (as of 2016) is the long British
Airlander 10
The Hybrid Air Vehicles Airlander 10, originally developed as the HAV 304, is a hybrid airship designed and built by British manufacturer Hybrid Air Vehicles (HAV). Comprising a helium airship with auxiliary wing and tail surfaces, it flies u ...
, a hybrid blimp, with helicopter and fixed-wing features, and reportedly capable of speeds up to , and an airborne endurance of two weeks with a payload of up to .
["World's largest aircraft the Airlander makes maiden flight in UK,"](_blank)
16 August 2016, London 'Daily Telegraph' via Telegraph.co.uk. Retrieved 22 November 2016.["Airlander 10, the world's largest aircraft, takes off for the first time," 19 August 2016, CBS News (TV) retrieved 22 November 2016.][Kottasova, Ivan]
"The world's largest aircraft crashes after 2nd test flight"
, 24 August 2016, ''CNN Tech'' on CNN
CNN (Cable News Network) is a multinational cable news channel headquartered in Atlanta, Georgia, U.S. Founded in 1980 by American media proprietor Ted Turner and Reese Schonfeld as a 24-hour cable news channel, and presently owned by ...
, the Cable News Network. Retrieved 22 November 2016.
The largest aircraft by weight and largest regular fixed-wing aircraft ever built, , was the
Antonov An-225 ''Mriya''. That Ukrainian-built six-engine Russian transport of the 1980s is long, with an wingspan. It holds the world payload record, after transporting of goods, and has recently flown loads commercially. With a maximum loaded weight of , it was also the heaviest aircraft built to date. It could cruise at .
["Watch the world's biggest plane land in Australia,"](_blank)
16 May 2016, Fox News. Retrieved 22 November 2016.[Rumbaugh, Andrea]
"World's biggest airplane lands at Bush airport,"
Updated 18 November 2016, ''Houston Chronicle'' / Chron.com. Retrieved 22 November 2016.[Lewis, Danny]
"The World's Largest Aircraft Might Lose its Title to a Blimp,"
18 September 2015, ''Smart News'', Smithsonian.com, Smithsonian Institution
The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums and education and research centers, the largest such complex in the world, created by the U.S. government "for the increase and diffusion of knowledge". Founded ...
, Washington, D.C.. Retrieved 22 November 2016.["Ask Us – Largest Plane in the World,"](_blank)
Aerospaceweb.org. Retrieved 22 November 2016. The aircraft was destroyed during the
Russo-Ukrainian War
The Russo-Ukrainian War; uk, російсько-українська війна, rosiisko-ukrainska viina. has been ongoing between Russia (alongside Russian separatists in Ukraine) and Ukraine since February 2014. Following Ukraine's Rev ...
.
The largest military airplanes are the Ukrainian
Antonov An-124 ''Ruslan'' (world's second-largest airplane, also used as a civilian transport),
["World's Second Largest Aircraft,"](_blank)
28 July 2013, NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
. Retrieved 22 November 2016. and American
Lockheed C-5 Galaxy transport, weighing, loaded, over .
[Loftin, Laurence K., Jr.]
"Wide-Body Transports"
, in Chapter 13, "Jet Transports," in Part II, "The Jet Age," in ''Quest for Performance: The Evolution of Modern Aircraft'', NASA SP-468, 1985, Scientific and Technical Information Branch, NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
, Washington, D.C., Updated: 6 August 2004. Retrieved 22 November 2016. The 8-engine, piston/propeller
Hughes H-4 ''Hercules'' "Spruce Goose" — an American
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
wooden flying boat transport with a greater wingspan (94m/260ft) than any current aircraft and a tail height equal to the tallest (Airbus A380-800 at 24.1m/78ft) — flew only one short hop in the late 1940s and never flew out of
ground effect.
The largest civilian airplanes, apart from the above-noted An-225 and An-124, are the
Airbus Beluga
The Airbus A300-600ST (Super Transporter), or Beluga, is a version of the standard A300-600 wide-body airliner modified to carry aircraft parts and outsize cargo. It received the official name of ''Super Transporter'' early on; however, the nam ...
cargo transport derivative of the
Airbus A300
The Airbus A300 is a wide-body airliner developed and manufactured by Airbus.
In September 1967, aircraft manufacturers in the United Kingdom, France, and West Germany signed a memorandum of understanding to develop a large airliner.
West ...
jet airliner, the Boeing Dreamlifter cargo transport derivative of the Boeing 747 jet airliner/transport (the 747-200B was, at its creation in the 1960s, the heaviest aircraft ever built, with a maximum weight of over ),
and the double-decker Airbus A380 "super-jumbo" jet airliner (the world's largest passenger airliner).
["Airbus reviews A380 schedule,"](_blank)
29 April 2008, ''The New York Times''. Retrieved 22 November 2016.
Speeds
The fastest recorded powered aircraft flight and fastest recorded aircraft flight of an air-breathing powered aircraft was of the NASA X-43A ''Pegasus'', a scramjet-powered, Hypersonic speed, hypersonic,
lifting body
A lifting body is a fixed-wing aircraft or spacecraft configuration in which the body itself produces lift. In contrast to a flying wing, which is a wing with minimal or no conventional fuselage, a lifting body can be thought of as a fuselage ...
experimental research aircraft, at Mach number, Mach 9.6, exactly . The X-43A set that new mark, and broke its own world record of Mach 6.3, exactly , set in March 2004, on its third and final flight on 16 November 2004.
["Hypersonic X-43A Takes Flight.htm,"](_blank)
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
retrieved November 2016.["Fastest aircraft, air-breathing engine,"](_blank)
Guinness World Records. Retrieved 2 December 2016.
Prior to the X-43A, the fastest recorded powered airplane flight (and still the record for the fastest manned, powered airplane / fastest manned, non-spacecraft aircraft) was of the North American X-15, North American X-15A-2, rocket-powered airplane at Mach 6.72, or , on 3 October 1967. On one flight it reached an altitude of .
[Jackson, Doug]
"Ask Us – Aircraft Speed Records,"
22 April 2001, Aerospaceweb.org. Retrieved 22 November 2016.["Fastest speed in a non-spacecraft aircraft,"](_blank)
Guinness World Records. Retrieved 2 December 2016.[Bergqvist, Pia]
"Fastest Airplanes: Top Performers in Their Class,"
17 September 2014, ''Flying (magazine), Flying''. Retrieved 3 December 2016
The fastest known, production aircraft (other than rockets and missiles) currently or formerly operational (as of 2016) are:
* The fastest fixed-wing aircraft, and fastest glider, is the
Space Shuttle
The Space Shuttle is a retired, partially reusable low Earth orbital spacecraft system operated from 1981 to 2011 by the U.S. National Aeronautics and Space Administration (NASA) as part of the Space Shuttle program. Its official program ...
, a rocket-glider hybrid, which has re-entered the atmosphere as a fixed-wing glider at more than Mach 25, equal to .
[Benson, Tom, ed.]
"Speed Regimes: Hypersonic Re-Entry,"
Glenn Research Center, NASA
The National Aeronautics and Space Administration (NASA ) is an independent agencies of the United States government, independent agency of the US federal government responsible for the civil List of government space agencies, space program ...
. Retrieved 22 November 2016.
* The fastest military airplane ever built: Lockheed SR-71 Blackbird, a U.S. reconnaissance jet fixed-wing aircraft, known to fly beyond Mach 3.3, equal to . On 28 July 1976, an SR-71 set the record for the fastest and highest-flying operational aircraft with an absolute speed record of and an absolute altitude record of . At its retirement in January 1990, it was the fastest air-breathing aircraft / fastest jet aircraft in the world, a record still standing .
["Lockheed SR-71A,"]
display notes, 29 May 2015, National Museum of the United States Air Force retrieved 2 December 2016[Trujillo, Staff Sgt. Robert M]
"SR-71 Blackbird: Gone but not forgotten,"
26 January 2016, 9th Reconnaissance Wing Public Affairs, U.S. Air Force. Retrieved 2 December 2016["Absolute speed record still stands 40 years later," 27 July 2016 ''General Aviation News''. Retrieved 22 November 2016.][Woolen, Angela]
"SR-71 pilots, crew relive absolute speed record,"
9 August 2016, 78th Air Base Wing Public Affairs, United States Air Force. Retrieved 2 December 2016
:Note: Some sources refer to the above-mentioned X-15 as the "fastest military airplane" because it was partly a project of the U.S. Navy and Air Force; however, the X-15 was not used in non-experimental actual military operations.
* The fastest current military aircraft are the Soviet/Russian Mikoyan-Gurevich MiG-25 — capable of Mach 3.2, equal to , at the expense of engine damage, or Mach 2.83, equal to , normally — and the Russian Mikoyan MiG-31E (also capable of Mach 2.83 normally). Both are fighter-interceptor jet airplanes, in active operations as of 2016.
[
Bender, Jeremy and Amanda Macias]
"The 9 fastest piloted planes in the world,"
18 September 2015, ''Business Insider''. Retrieved 3 December 2016["Fast and furious — the world's fastest military aircraft,"](_blank)
''Airforce Technology''. Retrieved 3 December 2016[The Five Fastest Military Jets Ever Made","](_blank)
2016, Bloomberg. Retrieved 3 December 2016
* The fastest civilian airplane ever built, and fastest passenger airliner ever built: the briefly operated Tupolev Tu-144 supersonic jet airliner (Mach 2.35, 1,600 mph, 2,587 km/h), which was believed to cruise at about Mach 2.2. The Tu-144 (officially operated from 1968 to 1978, ending after two crashes of the small fleet) was outlived by its rival, the ''Concorde'' (Mach 2.23), a French/British supersonic airliner, known to cruise at Mach 2.02 (1.450 mph, 2,333 kmh at cruising altitude), operating from 1976 until the small Concorde fleet was grounded permanently in 2003, following the crash of one in the early 2000s.
["Fastest aircraft, airliner,"](_blank)
Guinness World Records. Retrieved 2 December. 2016.
* The fastest civilian airplane currently flying: the Cessna Citation X, an American business jet, capable of Mach 0.935, or . Its rival, the American Gulfstream G650 business jet, can reach Mach 0.925, or
["Cessna rolls out first production unit of new Citation X,"](_blank)
15 April 2013, ''Wichita Business Journal''. Retrieved 22 November 2016.
* The fastest airliner currently flying is the Boeing 747, quoted as being capable of cruising over Mach 0.885, . Previously, the fastest were the troubled, short-lived Russian (Soviet Union) Tupolev Tu-144 SST (Mach 2.35; equal to ) and the French/British ''Concorde'', with a maximum speed of Mach 2.23 or and a normal cruising speed of Mach 2 or .
["Ask Us – Fastest Airliner and Area Rule,"](_blank)
Aerospaceweb.org. Retrieved 22 November 2016. Before them, the Convair 990 Coronado jet airliner of the 1960s flew at over .
Propulsion
Unpowered aircraft
Glider (aircraft), Gliders are heavier-than-air aircraft that do not employ propulsion once airborne. Take-off may be by launching forward and downward from a high location, or by pulling into the air on a tow-line, either by a ground-based winch or vehicle, or by a powered "tug" aircraft. For a glider to maintain its forward air speed and lift, it must descend in relation to the air (but not necessarily in relation to the ground). Many gliders can "soar", ''i.e.'', 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, whom many recognise as the first aeronautical engineer. Common examples of gliders are Glider (sailplane), sailplanes, Hang gliding, hang gliders and Paragliding, paragliders.
Balloon (aeronautics), 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 are aircraft 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-kite hybrids that are shaped and tethered to obtain kiting deflections, and can be lighter-than-air, neutrally buoyant, or heavier-than-air.
Powered aircraft
Powered aircraft have one or more onboard sources of mechanical power, typically aircraft engines although rubber and manpower have also been used. Most aircraft engines are either lightweight reciprocating engines or gas turbines. Engine fuel is stored in tanks, usually in the wings but larger aircraft also have additional fuel tanks in the fuselage.
Propeller aircraft
Powered aircraft#Propeller aircraft, Propeller aircraft use one or more
propellers
A propeller (colloquially often called a screw if on a ship or an airscrew if on an aircraft) is a device with a rotating hub and radiating blades that are set at a pitch to form a helical spiral which, when rotated, exerts linear thrust upon ...
(airscrews) to create thrust in a forward direction. The propeller is usually mounted in front of the power source in ''tractor configuration'' but can be mounted behind in ''pusher configuration''. Variations of propeller layout include ''contra-rotating propellers'' and ''ducted fans''.
Many kinds of power plant have been used to drive propellers. Early airships used man power or Steam aircraft, steam engines. The more practical Internal combustion engine, internal combustion piston engine was used for virtually all fixed-wing aircraft until
World War II
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
and is still used in many smaller aircraft. Some types use turbine engines to drive a propeller in the form of a turboprop or propfan. History of human-powered aircraft, Human-powered flight has been achieved, but has not become a practical means of transport. Unmanned aircraft and models have also used power sources such as Electric aircraft, electric motors and rubber bands.
Jet aircraft
Jet aircraft use airbreathing jet engines, which take in air, burn fuel with it in a combustion chamber, and accelerate the exhaust rearwards to provide thrust.
Different jet engine configurations include the turbojet and turbofan, sometimes with the addition of an afterburner. Those with no rotating turbomachinery include the pulsejet and ramjet. These mechanically simple engines produce no thrust when stationary, so the aircraft must be launched to flying speed using a catapult, like the V-1 flying bomb, or a rocket, for example. Other engine types include the motorjet and the dual-cycle Pratt & Whitney J58.
Compared to engines using propellers, jet engines can provide much higher thrust, higher speeds and, above about , greater efficiency.
They are also much more fuel-efficient than
rocket
A rocket (from it, rocchetto, , bobbin/spool) is a vehicle that uses jet propulsion to accelerate without using the surrounding air. A rocket engine produces thrust by reaction to exhaust expelled at high speed. Rocket engines work entirely fr ...
s. As a consequence nearly all large, high-speed or high-altitude aircraft use jet engines.
Rotorcraft
Some rotorcraft, such as
helicopter
A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...
s, have a powered rotary wing or ''
rotor
Rotor may refer to:
Science and technology
Engineering
* Rotor (electric), the non-stationary part of an alternator or electric motor, operating with a stationary element so called the stator
*Helicopter rotor, the rotary wing(s) of a rotorcraft ...
'', where the rotor disc can be angled slightly forward so that a proportion of its lift is directed forwards. The rotor may, like a propeller, be powered by a variety of methods such as a piston engine or turbine. Experiments have also used Tip jet, jet nozzles at the rotor blade tips.
Other types of powered aircraft
* ''Rocket-powered aircraft'' have occasionally been experimented with, and the Messerschmitt Me 163 Komet, Messerschmitt Me 163 ''Komet'' fighter even saw action in the Second World War. Since then, they have been restricted to research aircraft, such as the North American X-15, which traveled up into space where air-breathing engines cannot work (rockets carry their own oxidant). Rockets have more often been used as a supplement to the main power plant, typically for the JATO, rocket-assisted take off of heavily loaded aircraft, but also to provide high-speed dash capability in some hybrid designs such as the Saunders-Roe SR.53.
* The ''
ornithopter
An ornithopter (from Greek ''ornis, ornith-'' "bird" and ''pteron'' "wing") is an aircraft that flies by flapping its wings. Designers sought to imitate the flapping-wing flight of birds, bats, and insects. Though machines may differ in form, ...
'' obtains thrust by flapping its wings. It has found practical use in a Ornithopter#Applications for unmanned ornithopters, model hawk used to freeze prey animals into stillness so that they can be captured, and in toy birds.
Design and construction
Aircraft are aircraft design process, designed according to many factors such as customer and manufacturer demand, Aviation safety, safety protocols and physical and economic constraints. For many types of aircraft the design process is regulated by national airworthiness authorities.
The key parts of an aircraft are generally divided into three categories:
* The ''structure'' ("airframe"
[Gove, P.B., editor: ''Webster's Third New International Dictionary of the English Language, Unabridged,'' 1993, Merriam-Webster, Springfield, Mass., USA][Crane, D., editor: ''Dictionary of Aeronautical Terms,'' Third Edition, ASA (Aviation Supplies & Academics), Newcastle, Washington, USA][''2012 Federal Aviation Regulations for Aviation Maintenance Technicians,'' 2012, Federal Aviation Administration, U.S. Department of Transportation][Bill Gunston, Gunston, Bill, editor: ''Jane's Aerospace Dictionary'' 1980, Jane's, London / New York / Sydney]) comprises the main load-bearing elements and associated equipment, as well as flight controls.
* The ''propulsion system'' ("powerplant"
["Glossary"](_blank)
in ''Pilot's Handbook of Aeronautical Knowledge'' (PHAK), Federal Aviation Administration, Washington, D.C., retrieved September 12, 2022) (if it is powered) comprises the power source and associated equipment, as described above.
* The ''avionics'' comprise the electrical and electronic control, navigation and communication systems.
[Wragg, David W. editor: ''A Dictionary of Aviation,'' 1974, Frederick Fell, New York]
Structure
The approach to structural design varies widely between different types of aircraft. Some, such as paragliders, comprise only flexible materials that act in tension and rely on aerodynamic pressure to hold their shape. A
balloon
A balloon is a flexible bag that can be inflated with a gas, such as helium, hydrogen, nitrous oxide, oxygen, and air. For special tasks, balloons can be filled with smoke, liquid water, granular media (e.g. sand, flour or rice), or light so ...
similarly relies on internal gas pressure, but may have a rigid basket or gondola slung below it to carry its payload. Early aircraft, including
airship
An airship or dirigible balloon is a type of aerostat or lighter-than-air aircraft that can navigate through the air under its own power. Aerostats gain their lift from a lifting gas that is less dense than the surrounding air.
In early ...
s, often employed flexible Aircraft dope, doped aircraft fabric covering to give a reasonably smooth aeroshell stretched over a rigid frame. Later aircraft employed semi-monocoque techniques, where the skin of the aircraft is stiff enough to share much of the flight loads. In a true monocoque design there is no internal structure left. With the recent emphasis on sustainability hemp has picked up some attention, having a way smaller carbon foot print and 10 times stronger than steel, hemp could become the standard of manufacturing in the future.
The key structural parts of an aircraft depend on what type it is.
Aerostats
Lighter-than-air types are characterised by one or more gasbags, typically with a supporting structure of flexible cables or a rigid framework called its hull. Other elements such as engines or a gondola may also be attached to the supporting structure.
Aerodynes
Heavier-than-air types are characterised by one or more wings and a central fuselage. The fuselage typically also carries a tail or empennage for stability and control, and an undercarriage for takeoff and landing. Engines may be located on the fuselage or wings. On a
fixed-wing aircraft the wings are rigidly attached to the fuselage, while on a
rotorcraft
A rotorcraft or rotary-wing aircraft is a heavier-than-air aircraft with rotary wings or rotor blades, which generate lift by rotating around a vertical mast. Several rotor blades mounted on a single mast are referred to as a rotor. The Internat ...
the wings are attached to a rotating vertical shaft. Smaller designs sometimes use flexible materials for part or all of the structure, held in place either by a rigid frame or by air pressure. The fixed parts of the structure comprise the airframe.
Power
The source of motive power for an aircraft is normally called the ''powerplant,'' and includes engine or motor, propeller or
rotor
Rotor may refer to:
Science and technology
Engineering
* Rotor (electric), the non-stationary part of an alternator or electric motor, operating with a stationary element so called the stator
*Helicopter rotor, the rotary wing(s) of a rotorcraft ...
, (if any), jet nozzles and thrust reversers (if any), and accessories essential to the functioning of the engine or motor (e.g.: Starter motor, starter, ignition system, intake, intake system, exhaust system, Aircraft fuel system, fuel system, lubrication system, engine cooling system, and engine controls).
["Glossary"](_blank)
in ''Pilot's Handbook of Aeronautical Knowledge'' (PHAK), Federal Aviation Administration, Washington, D.C., retrieved September 12, 2022
Powered aircraft are typically powered by internal combustion engines (piston engine, piston
["Internal Combustion Engine,"](_blank)
Glenn Research Center, National Aeronautics and Space Administration (NASA), retrieved September 12, 2022 or gas turbine engine, turbine
["Engines,"](_blank)
Glenn Research Center, National Aeronautics and Space Administration (NASA), retrieved September 12, 2022) burning fossil fuels -- typically gasoline (avgas) or jet fuel. A very few are powered by rocket engine, rocket power, ramjet propulsion, or by electric motors, or by internal combustion engines of other types, or using other fuels. A very few have been powered, for short flights, by human-powered aircraft, human muscle energy (e.g.: Gossamer Condor).
[Bryan, C.D.B.: ''The National Air and Space Museum,'' 1979 / 1984, Abrams, New York][Taylor, Michael J.H., editor: ''Jane's Encyclopedia of Aviation,'' 1989 ed., Portland House / Random House, New York]["Electrified Aircraft Propulsion" (EAP)](_blank)
Glenn Research Center, National Aeronautics and Space Administration (NASA), retrieved September 12, 2022
Avionics
The avionics comprise any ''electronic'' aircraft flight control systems and related equipment, including electronic cockpit instrumentation, navigation, radar, monitoring, and communications systems.
[Wragg, David W. editor: ''A Dictionary of Aviation,'' 1974, Frederick Fell, New York]
Flight characteristics
Flight envelope
The flight envelope of an aircraft refers to its approved design capabilities in terms of airspeed, Load factor (aeronautics), load factor and altitude. The term can also refer to other assessments of aircraft performance such as maneuverability. When an aircraft is abused, for instance by diving it at too-high a speed, it is said to be flown ''outside the envelope'', something considered foolhardy since it has been taken beyond the design limits which have been established by the manufacturer. Going beyond the envelope may have a known outcome such as Aeroelasticity#Flutter, flutter or entry to a non-recoverable spin (possible reasons for the boundary).
Range
The range is the distance an aircraft can fly between takeoff and landing, as limited by the time it can remain airborne.
For a powered aircraft the time limit is determined by the fuel load and rate of consumption.
For an unpowered aircraft, the maximum flight time is limited by factors such as weather conditions and pilot endurance. Many aircraft types are restricted to daylight hours, while balloons are limited by their supply of lifting gas. The range can be seen as the average ground speed multiplied by the maximum time in the air.
The Airbus A350#A350-900ULR, Airbus A350-900ULR is now the longest range airliner.
Flight dynamics
Flight dynamics is the science of air vehicle orientation and control in three dimensions. The three critical flight dynamics parameters are the Angle of rotation, angles of rotation around Aircraft principal axes, three axes which pass through the vehicle's Center of mass#Center of gravity, center of gravity, known as ''Aircraft principal axes#Pitch, pitch'', ''Aircraft principal axes#Roll, roll,'' and ''Aircraft principal axes#Yaw, yaw''.
* Roll is a rotation about the longitudinal axis (equivalent to the rolling or Sailing#Heeling, heeling of a ship) giving an up-down movement of the wing tips measured by the roll or bank angle.
* Pitch is a rotation about the sideways horizontal axis giving an up-down movement of the aircraft nose measured by the angle of attack.
* Yaw is a rotation about the vertical axis giving a side-to-side movement of the nose known as sideslip.
Flight dynamics is concerned with the stability and control of an aircraft's rotation about each of these axes.
Stability
An aircraft that is unstable tends to diverge from its intended flight path and so is difficult to fly. A very stable aircraft tends to stay on its flight path and is difficult to maneuver. Therefore, it is important for any design to achieve the desired degree of stability. Since the widespread use of digital computers, it is increasingly common for designs to be inherently unstable and rely on computerised control systems to provide artificial stability.
A fixed wing is typically unstable in pitch, roll, and yaw. Pitch and yaw stabilities of conventional fixed wing designs require Stabilizer (aeronautics), horizontal and vertical stabilisers,
[Crane, Dale: ''Dictionary of Aeronautical Terms, third edition'', p. 194. Aviation Supplies & Academics, 1997. ][Aviation Publishers Co. Limited, ''From the Ground Up'', p. 10 (27th revised edition) ] which act similarly to the feathers on an arrow.
These stabilizing surfaces allow equilibrium of aerodynamic forces and to stabilise the flight dynamics of pitch and yaw.
They are usually mounted on the tail section (empennage), although in the Canard (aeronautics), canard layout, the main aft wing replaces the canard foreplane as pitch stabilizer. Tandem wing and tailless aircraft rely on the same general rule to achieve stability, the aft surface being the stabilising one.
A rotary wing is typically unstable in yaw, requiring a vertical stabiliser.
A balloon is typically very stable in pitch and roll due to the way the payload is slung underneath the center of lift.
Control
Flight control surfaces enable the pilot to control an aircraft's Flight dynamics (fixed-wing aircraft), flight attitude and are usually part of the wing or mounted on, or integral with, the associated stabilizing surface. Their development was a critical advance in the history of aircraft, which had until that point been uncontrollable in flight.
Aerospace engineering, 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 Moment (physics), 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. Control systems are also sometimes used to increase or decrease drag, for example to slow the aircraft to a safe speed for landing.
The two main aerodynamic forces acting on any aircraft are lift supporting it in the air and Drag (physics), drag opposing its motion. Control surfaces or other techniques may also be used to affect these forces directly, without inducing any rotation.
Impacts of aircraft use
Aircraft permit long distance, high speed Air travel, travel and may be a more Energy efficiency in transport#Aircraft, fuel efficient mode of transportation in some circumstances. Aircraft have Environmental impact of aviation, environmental and climate impacts beyond fuel efficiency considerations, however. They are also relatively Aircraft noise pollution, noisy compared to other forms of travel and high altitude aircraft generate contrails, which experimental evidence suggests may global dimming, alter weather patterns.
Uses for aircraft
Aircraft are produced in several different types optimized for various uses; military aircraft, which includes not just combat types but many types of supporting aircraft, and civil aviation, civil aircraft, which include all non-military types, experimental and model.
Military
A military aircraft is any aircraft that is operated by a legal or insurrectionary armed service of any type.
Military aircraft can be either combat or non-combat:
* Combat aircraft are aircraft designed to destroy enemy equipment using its own armament.
Combat aircraft divide broadly into Fighter aircraft, fighters and bombers, with several in-between types, such as fighter-bombers and attack aircraft, including attack helicopters.
* Non-combat aircraft are not designed for combat as their primary function, but may carry weapons for self-defense. Non-combat roles include search and rescue, reconnaissance, observation, transport, training, and aerial refueling. These aircraft are often variants of civil aircraft.
Most military aircraft are powered heavier-than-air types. Other types, such as 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
World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposing ...
to land troops.
Civil
Civil aircraft divide into ''commercial'' and ''general'' types, however there are some overlaps.
Commercial aviation, Commercial aircraft include types designed for scheduled and charter airline flights, carrying passengers, Airmail, mail and other cargo. The larger passenger-carrying types are the 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 Air transports of heads of state and government, VIP aircraft.
General aviation is a catch-all covering other kinds of Private aviation, private (where the pilot is not paid for time or expenses) and commercial use, and involving a wide range of aircraft types such as Business jet, business jets (bizjets), Trainer aircraft, trainers, Homebuilt aircraft, homebuilt,
gliders, warbirds and
hot air balloon
A hot air balloon is a lighter-than-air aircraft consisting of a bag, called an envelope, which contains heated air. Suspended beneath is a gondola or wicker basket (in some long-distance or high-altitude balloons, a capsule), which carries ...
s to name a few. The vast majority of aircraft today are general aviation types.
Experimental
An experimental aircraft is one that has not been fully proven in flight, or that carries a Airworthiness certificate#Special Airworthiness Certificate, Special Airworthiness Certificate, called an Experimental Certificate in United States parlance. This often implies that the aircraft is testing new aerospace technologies, though the term also refers to amateur-built and kit-built aircraft, many of which are based on proven designs.
Model
A model aircraft is a small unmanned type made to fly for fun, for static display, for aerodynamic research or for other purposes. A scale model is a replica of some larger design.
See also
Lists
* Early flying machines
* Flight altitude record
* List of aircraft
* List of civil aircraft
* List of fighter aircraft
* List of individual aircraft
* List of large aircraft
* wikt:Appendix:Glossary of aviation, aerospace, and aeronautics, List of aviation, aerospace and aeronautical terms
Topics
* Aircraft hijacking
* Aircraft spotting
* Air traffic control
* Airport
* Flying car
* Personal air vehicle
* Powered parachute
* Spacecraft
* Spaceplane
References
*
External links
History
The Evolution of Modern Aircraft (NASA)Smithsonian Air and Space Museum- online collection with a particular focus on history of aircraft and spacecraft
Amazing Early Flying Machines slideshow by ''Life (magazine), Life'' magazine
Information
Airliners.netAviation Dictionary- free aviation terms, phrases and jargons
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