A proprotor is a spinning airfoil that is used as both an airplane-style propeller and a helicopter-style rotor during the same flight. Proprotors are typically used on vertical takeoff and landing (VTOL) aircraft.
The dual-role airfoil is accomplished by one of several design approaches:
- changing the angle of attack of the wing that the proprotor is attached to, from approximately zero degrees to around ninety degrees: a tiltwing aircraft,
- changing the angle of attack of only the rotor hub, and possibly the engine that drives it, as on a tiltrotor,
- changing the angle of attack of the entire aircraft, as on a tailsitter, which launches and lands on its tail.
- United States Navy—V-22 Osprey Web
- Smriti Rao (January 20, 2010). "Meet the "Puffin," NASA's One-Man Electric Plane". Discover Magazine.