Aircraft First Flown In 1970

An aircraft is a vehicle that is able to fly by gaining support from the air. It 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. Common examples of aircraft include airplanes, helicopters, airships (including blimps), gliders, paramotors, and hot air balloons.

The human activity that surrounds aircraft is called ''aviation''. The science of aviation, including designing and building aircraft, is called ''aeronautics.'' Crewed aircraft are flown by an onboard pilot, but unmanned aerial vehicles may be remotely controlled or self-controlled by onboard computers. Aircraft may be classified by different criteria, such as lift type, aircraft propulsion, usage and others.

History

Flying model craft and stories of manned flight go back many centuries; however, the first manned ascent — and safe descent — in modern times took place by larger hot-air balloons developed in the 18th century. Each of the two World Wars 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, 1914 to 1918.
* Aviation between the World Wars, 1918 to 1939.
* Second World War, 1939 to 1945.
* Postwar era, also called the Jet Age, 1945 to the present day.

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 cells 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, 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 kites, which were first invented in ancient China over two thousand years ago. (See Han Dynasty)

A balloon was originally any aerostat, while the term airship was used for large, powered aircraft designs — usually fixed-wing. In 1919, Frederick Handley Page 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 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 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 gasbag with stabilizing fins at the back. These soon became known as ''blimps''. During World War II, 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, such as airplanes, 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, 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 downward. V/STOL aircraft, such as the Harrier jump jet and Lockheed Martin F-35B take off and land vertically using powered lift and transfer to aerodynamic lift in steady flight.

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

The practical, powered, fixed-wing aircraft (the airplane or aeroplane) was invented by Wilbur and Orville Wright. Besides the method of propulsion, fixed-wing aircraft are in general 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 stabilizing and control surfaces.

Wing-in-ground-effect 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". 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 with aerofoil cross-section blades (a ''rotary wing'') to provide lift. Types include helicopters, autogyros, and various hybrids such as gyrodynes and compound rotorcraft.

''Helicopters'' 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 to counteract the rotation of the main rotor, and to aid directional control.

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

''Cyclogyros'' 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'' types and not as rotorcraft. ''Tiltrotor'' aircraft (such as the Bell Boeing V-22 Osprey), tiltwing, tail-sitter, and coleopter aircraft have their rotors/propellers horizontal for vertical flight and vertical for forward flight.

Other methods of lift

* A ''lifting body'' is an aircraft body shaped to produce lift. If there are any wings, they are too small to provide significant lift and are used only for stability and control. Lifting bodies are not efficient: they suffer from high drag, and must also travel at high speed to generate enough lift to fly. Many of the research prototypes, such as the Martin Marietta X-24, which led up to the Space Shuttle, were lifting bodies, though the Space Shuttle is not, and some supersonic missiles obtain lift from the airflow over a tubular body.
* ''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 Bell Boeing V-22 Osprey, 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 research designs include the Rolls-Royce Thrust Measuring Rig.
* The ''Flettner airplane'' uses a rotating cylinder in place of a fixed wing, obtaining lift from the Magnus effect.
* The ''ornithopter'' 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, 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,"
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, 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,"
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, Washington, D.C.. Retrieved 22 November 2016."Ask Us – Largest Plane in the World,"
Aerospaceweb.org. Retrieved 22 November 2016. The aircraft was destroyed during the Russo-Ukrainian War.

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,"
28 July 2013, NASA. 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, 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 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 cargo transport derivative of the Airbus A300 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,"
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