Aircraft are machines that achieve flight through various methods of thrust and lift. They include vehicles such as airplanes, helicopters, gliders, airships, and balloons. These vehicles benefit from the comparably-low amounts of friction and drag experienced during travel. Since the implementation of safe and modern air travel, aircraft are the go-to solution for the rapid transit of people and freight across vast distances. Aircraft have also become the foremost instrument of military engagement. People largely regard the experience of flight as sensational, so there is an ever-growing market for recreational aviation as well. While fixed wing and rotary wing aircraft are amongst the fastest and most powerful vehicles ever created, lighter-than-air vehicles are actually quite slow.
Jet fighter; glider; coaxial helipter; Zeppelin airship
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Essentially, aircraft can be categorized as such:
- Fixed wing aircraft:
- Airplanes harness the fluid propulsion of a propeller or jet engine to create lift underneath wings with a load-proportional lift-to-drag ratio. These are the fastest, most common, and furthest innovated type of aircraft.
- Gliders rely on the same physical principles as airplanes, but do not utilize any type of constant mechanized propulsion. Instead, these heavier-than-air vehicles rely on the forward lift of air against its wings as it travels, as well as other meteorological phenomena. Gliders often require a mechanized launch or take-off, which may even include a small on-board motor. Some airplanes can function as a glider in instances of engine failure.
- Rotary wing aircraft spin rotors at a rate to create upward lift. While not as fast as planes, rotary wing aircraft have better maneuverability. Rotors are essentially large, vertical-axis propellers. The most common type of rotary wing aircraft is by far the helicopter, which establishes a carriage underneath a spinning rotor and horizontal-axis to combat the counter-torque produced. The counter-torque can also be combated by the use of two opposite-spinning rotors about the same vertical axis, or two rotors positioned along a line. Gyrodynes, rotor kites, autogyros, and cyclogyros are other types of rotary wing aircraft but are commercially and militarily insignificant.
- Lighter-than-air aircraft capture heated air or chemical gases -- which have densities less than Earth's atmosphere -- within a large ballast to create lift. A carriage underneath the ballast provides room for passengers and it also orients the vehicle.
- Airships incorporate rotors, engines, or thrusters to help direct the vehicle through airspace. Ballasts of airships may use a rigid, semi-rigid, or non-rigid ballast construction.
- Balloons heat air and capture it within a ballast; operators sit within a suspended gondola and are responsible for the ascent/descent of the balloon. Balloons, in general, are not steerable. They are the oldest form of aircraft, dating to 1783.
- Spacecraft are sometimes considered aircraft, but only because they use Earth's atmosphere as an avenue between destinations. As such, their suspended flight capabilities are very limited. The United States now-defunct Space Shuttles were analogous to 'flying bricks' according to NASA.