A flying machine is a type of aircraft that is capable of taking off and landing vertically, or with very short runways. The most common types of flying machines are aeroplanes, whirlybirds, copters, helicopters, gyroplanes, and planes. Aeroplanes are powered by propellers or jet engines and have fixed wings. Whirlybirds are a type of HELICOPTER that has two rotors and is used mainly for military purposes. Copters are a type of HELICOPTER that has one main rotor and one tail rotor. Helicopters are a type of aircraft that use rotors to generate lift and thrust. Gyroplanes are a type of aircraft that use an unpowered rotor in autorotation to generate lift and thrust. Planes are a type of aircraft that use wings to generate lift and thrust.