All three classes have been studied for use as lifting rotors and several variations have been flown on full-size aircraft, although only the vertical-axis rotary wing has become widespread on rotorcraft such as the helicopter.
Some types provide lift at zero forward airspeed, allowing for vertical takeoff and landing (VTOL), as in the helicopter.
The American Plymouth A-A-2004 floatplane had Flettner rotors in place of the main wings and achieved short flights in 1924.
During World War II Focke-Wulf proposed the Triebflügel, in which a tipjet-driven rotor wing is located around the fuselage waist.
[5] A few years later the American Vought XF5U circular-winged fighter prototype was designed with large radial-lift propellers.