Aircraft


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 the dynamic lift of an airfoil, or, in a few cases, direct downward thrust from its engines. Common examples of aircraft include airplanes, drones, rotorcraft, airships, gliders, paramotors, and hot air balloons. Part 1 of Subchapter A of Chapter I of Title 14 of the U. S. Code of Federal Regulations states that aircraft "means a device that is used or intended to be used for flight in the air."
The human activity that surrounds aircraft is called aviation. The science of aviation includes, designing and building aircraft, is called aeronautics. Crewed aircraft are flown by an onboard pilot, whereas 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

The history of aviation spans over two millennia, from the earliest innovations like kites and attempts at tower jumping to supersonic and hypersonic flight in powered, heavier-than-air jet aircraft. Kite flying in China, dating back several hundred years BC, is considered the earliest example of man-made flight. In the 15th century, Leonardo da Vinci created flying machine designs incorporating aeronautical concepts, but they were unworkable due to the limitations of contemporary knowledge.
In the late 18th century, the Montgolfier brothers invented the hot-air balloon which soon led to manned flights. At almost the same time, the discovery of hydrogen gas led to the invention of the hydrogen balloon. Various theories in mechanics by physicists during the same period, such as fluid dynamics and Newton's laws of motion, led to the development of modern aerodynamics; most notably by Sir George Cayley. Balloons, both free-flying and tethered, began to be used for military purposes from the end of the 18th century, with France establishing balloon companies during the French Revolution.
In the 19th century, especially the second half, experiments with gliders provided the basis for learning the dynamics of winged aircraft; most notably by Cayley, Otto Lilienthal, and Octave Chanute. By the early 20th century, advances in engine technology and aerodynamics made controlled, powered, manned heavier-than-air flight possible for the first time. In 1903, following their pioneering research and experiments with wing design and aircraft control, the Wright brothers successfully incorporated all of the required elements to create and fly the first airplane. In 1906 Charles Frederick Page was granted the first U.S. patent for an aircraft. The basic configuration with its characteristic cruciform tail was established by 1909, followed by rapid design and performance improvements aided by the development of more powerful engines.
The first vessels of the air were the rigid steerable balloons pioneered by Ferdinand von Zeppelin that became synonymous with airships and dominated long-distance flight until the 1930s, when large flying boats became popular for trans-oceanic routes. After World War II, the flying boats were in turn replaced by airplanes operating from land, made far more capable first by improved propeller engines, then by jet engines, which revolutionized both civilian air travel and military aviation.
In the latter half of the 20th century, the development of digital electronics led to major advances in flight instrumentation and "fly-by-wire" systems. The 21st century has seen the widespread use of pilotless drones for military, commercial, and recreational purposes. With computerized controls, inherently unstable aircraft designs, such as flying wings, have also become practical.

Methods of lift

Lighter-than-air

Lighter-than-air aircraft or 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 lifting gas such as helium, hydrogen or hot air, which is less dense than the surrounding air. Other gases lighter than air also theoretically work, however, such gases also needs to be safe for human use.
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, although they also had military purposes. They, along with kites, were two forms of unmanned aircraft that originated from China. Kites were also used in the military, but unlike sky lanterns, their flight is caused by the differences of air pressure beneath and above the kite.
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".
Lighter-than-air aircraft don't typically require a pilot's license in the United States. In most countries in Europe, standards for flying Lighter-than-air aircraft tend to be stricter compared to the United States.

Heavier-than-air

Heavier-than-air aircraft or aerodynes are denser than air and thus must find some way to obtain enough lift that can overcome the aircraft's weight. There are two ways to produce dynamic upthrust — aerodynamic lift by having air flowing past an aerofoil, or powered lift in the form of reactional lift from downward engine thrust.
Aerodynamic lift involving wings is the most common, and can be achieved via two methods. Fixed-wing aircraft achieve airflow past the wings by having the entire aircraft moving forward through the air, while rotorcraft do so by having mobile, elongated wings spinning rapidly around a mast in an assembly known as the rotor.

Fixed-wing aircraft

were one of the first forms of a fixed wing aircraft. They are a special type of aircraft that doesn't require an engine. The first person to successfully build a human-carrying glider was George Cayley, who also was the first to discover the four major aerodynamic forces. The first powered aircraft was invented by Wilbur and Orville Wright.

Rotorcraft

A rotary-wing aircraft, rotorwing aircraft or rotorcraft is a heavier-than-air aircraft with rotary wings that spin around a vertical mast to generate lift. The assembly of several rotor blades mounted on a single mast is referred to as a rotor. The International Civil Aviation Organization defines a rotorcraft as "supported in flight by the reactions of the air on one or more rotors".
Rotorcraft generally include aircraft where one or more rotors provide lift throughout the entire flight, such as helicopters, gyroplanes, autogyros, and gyrodynes Compound rotorcraft augment the rotor with additional thrust engines, propellers, or static lifting surfaces. Some types, such as helicopters, are capable of vertical takeoff and landing. An aircraft which uses rotor lift for vertical flight but changes to solely fixed-wing lift in horizontal flight is not a rotorcraft but a convertiplane.

Other methods of lift

  • A lifting body is an aircraft which produces lift through the shape of its body, rather than its wings or rotors, like conventional aircraft. Lifting bodies were first experimented by NASA in the 1960s-70s, but the idea was already conceived in the 1950s.
  • A powered lift aircraft is one which has the capability of vertical takeoff and landing. These aircraft must transition from vertical to lateral movement, which is considered the most dangerous phases of a flight. Classes of powered lift types include VTOL jet aircraft and tiltrotors, such as the Bell Boeing V-22 Osprey, among others.
  • An ornithopter is an aircraft that produces lift through the movement of its wings, akin to how a bird flies.

    Size and speed extremes

Size

The largest aircraft by dimensions and volume 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.
The largest aircraft by weight and largest regular fixed-wing aircraft ever built, as of 2016, was the Antonov An-225 Mriya. That Soviet-built six-engine transport of the 1980s was long, with an wingspan. It holds the world payload record, after transporting of goods, and has flown loads commercially. With a maximum loaded weight of, it was also the heaviest aircraft built to date. It could cruise at. The aircraft was destroyed during the Russo-Ukrainian War.
The largest military airplanes are the Ukrainian Antonov An-124 Ruslan, and American Lockheed C-5 Galaxy transport, weighing, loaded, over. The 8-engine, piston/propeller Hughes H-4 Hercules "Spruce Goose" — an American World War II wooden flying boat transport with a greater wingspan than any current aircraft and a tail height equal to the tallest — 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, and the double-decker Airbus A380 "super-jumbo" jet airliner.

Speeds

The fastest fixed-wing aircraft and fastest glider, is the Space Shuttle, which re-entered the atmosphere at nearly Mach 25 or
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, lifting body experimental research aircraft, at Mach 9.68 or on 16 November 2004.
Prior to the X-43A, the fastest recorded powered airplane flight, and still the record for the fastest manned powered airplane, was the North American X-15, rocket-powered airplane at Mach 6.7 or 7,274 km/h on 3 October 1967.
The fastest manned, air-breathing powered airplane is the Lockheed SR-71 Blackbird, a U.S. reconnaissance jet fixed-wing aircraft, having reached on 28 July 1976.