Proprotor
From Wikipedia, the free encyclopedia
A proprotor is a spinning airfoil that function as both an airplane-style propeller and a helicopter-style rotor. Several proprotor-equipped convertiplanes, such as the Bell Boeing V-22 Osprey tiltrotor, are capable of switching back and forth between flying akin to both helicopters and fixed-wing aircraft.[1] Accordingly this type of airfoil has been predominantly applied to 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.[2]