Powered lift

An USAF CV-22 in flight

The powered rotors of a tiltrotor (sometimes called proprotor) are mounted on rotating shafts or nacelles at the end of a fixed wing, and used for both lift and propulsion. For vertical flight, the rotors are angled to provide thrust upwards, lifting the way a helicopter rotor does. As the aircraft gains speed, the rotors progressively rotate or tilt forward, with the rotors eventually becoming perpendicular to the fuselage of the aircraft, similar to a propeller. In this mode, the wing provides the lift and the rotor provides thrust. The wing's greater efficiency helps the tiltrotor achieve higher speeds than helicopters.

The Osprey by Bell Helicopter and Boeing is a twin-engine tiltrotor design that has two turbine engines each driving three-blade rotors. The rotors function similar to a helicopter in vertical flight, and similar to an airplane in forward flight. It first flew on 19 March 1989. The AgustaWestland AW609 (formerly Bell/Agusta BA609) tiltrotor is civilian aircraft based on the V-22 Osprey. The aircraft can take off and land vertically with 2 crew and 9 passengers. The aircraft is expected to be certified in the mid-2020s.

The tiltwing is similar to the tiltrotor, except that the rotor mountings are fixed to the wing and the whole assembly tilts between vertical and horizontal positions.

The Vertol VZ-2 was a research aircraft developed in the late 1950s. Unlike other tiltwing aircraft, Vertol designed the VZ-2 using rotors in place of propellers.[2] On 23 July 1958, the aircraft made its first full transition from vertical flight to horizontal flight. By the time the aircraft was retired in 1965, the VZ-2 had accomplished 450 flights, including 34 full transitions.

A rotor wing aircraft has been attempted but is not in wide use. The Boeing X-50 Dragonfly had a two-bladed rotor driven by the engine for takeoff. In horizontal flight the rotor stopped to act like a wing. Fixed canard and tail surfaces provided lift during transition, and also stability and control in forward flight. Both examples of this aircraft were destroyed in crashes. The Sikorsky X-Wing had a four-bladed rotor utilizing compressed air to control lift over the surfaces while operating as a helicopter. At higher forward speeds, the rotor would be stopped to continue providing lift as tandem wings in an X configuration. The program was canceled before the aircraft had attempted any flights with the rotor system.

The Harrier family of military VSTOL jet aircraft uses thrust vectoring. These aircraft are capable of vertical/short takeoff and landing (V/STOL). They are the only truly successful design of this type from the many that arose in the 1960s. These aircraft are capable of operating from small spaces, such as fields, roads, and aviation-capable ships. The Lockheed F-35B Lightning II is proposed as the next military VSTOL/STOVL design, to replace the Harrier.

A lift jet is a lightweight jet engine used to provide vertical thrust for VTOL operation, and is then shut down in forward flight. Some VTOL designs have used both vectored thrust from the main engine together with auxiliary lift jets.

A lift fan configuration is where the lifting fans are located in large holes in an otherwise conventional fixed wing or fuselage. It is used for V/STOL operation. The aircraft takes off using the fans to provide lift, then transitions to more convention fixed-wing forward flight. Several experimental craft have been flown, but only the F-35 Lightning II entered into production.