Types of Aircraft
Aircraft require a support from the atmosphere called the lift in order to sustain themselves in flight. Aircraft are broadly separated into lighter-than-air (LTA) and heavier-than-air (or aerodynamic lifting) vehicles, depending, respectively, upon whether the lift is produced by buoyancy, or by the motion of the vehicle (or a part of the vehicle) through the air.
Into the LTA category fall the balloons and airships, while the aerodynamic lifting vehicles are classified as being either fixed-wing, or rotary-wing craft depending upon whether their wings are fixed or rotary relative to the main structure.
The fixed-wing aircraft include the airplanes and the gliders, whereas the rotary-wing vehicles (also termed the rotorcraft) are the helicopters and autogyros. Although there is no flapping-wing flight vehicle currently in operation, they can be thought of as being aerodynamic vehicles in a class separate from the fixed-wing and the rotary-wing vehicles.