The Sikorsky XV-2, also known by the

Sikorsky Aircraft Sikorsky Aircraft is an American aircraft manufacturer based in Stratford, Connecticut. It was established by aviation pioneer Igor Sikorsky in 1923 and was among the first companies to manufacture helicopters for civilian and military use. Pre ...

model number S-57, was a planned experimental stoppable rotor aircraft, designated as a

convertiplane A convertiplane is defined by the Fédération Aéronautique Internationale (FAI or World Air Sports Federation) as an aircraft which uses rotor power for vertical takeoff and landing (VTOL) and converts to fixed-wing lift in normal flight. In the ...

, developed for a joint research program between the

United States Air Force The United States Air Force (USAF) is the air service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part of the United States Army Signal ...

and the

United States Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, cla ...

. The program was cancelled before construction of the prototype began.

Design and development

The XV-2 was developed as part of a joint U.S. Air Force and U.S. Army program intended to explore technologies to develop an

aircraft An aircraft is a vehicle that is able to fly by gaining support from the air. It counters the force of gravity by using either static lift or by using the dynamic lift of an airfoil, or in a few cases the downward thrust from jet engines ...

that could take off and land like a

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...

but fly at faster airspeeds, similar to a conventional

airplane An airplane or aeroplane (informally plane) is a fixed-wing aircraft that is propelled forward by thrust from a jet engine, propeller, or rocket engine. Airplanes come in a variety of sizes, shapes, and wing configurations. The broad spe ...

. The XV-2's stoppable-rotor design was intended to allow it to hover and fly at low speed like a conventional

. It utilized a single-rotor design; a counterweight provided stability to the rotor system, while a tip-jet arrangement powered the rotor, which retracted into the upper fuselage when stopped, the XV-2 then flying like a conventional aircraft on

delta wing A delta wing is a wing shaped in the form of a triangle. It is named for its similarity in shape to the Greek uppercase letter delta (Δ). Although long studied, it did not find significant applications until the Jet Age, when it proved suitabl ...

s. A single jet engine was provided for forward flight. The XV-2 prototype was assigned the serial number 53-4403, but the project was cancelled before construction could begin.Pearcy 1993, p.103.

References

;Citations ;Bibliography * * * *

External links

Helis.com: Sikorsky History part 2
{{US STOL and VTOL aircraft Cancelled military aircraft projects of the United States Gyrodynes V-002 Stoppable rotor helicopters Single-engined jet aircraft Tipjet-powered helicopters High-wing aircraft

Design and development

See also

References

External links