A vertical take-off and landing (VTOL) aircraft is one that can hover, take off, and land vertically. This classification can include a variety of types of aircraft including fixed-wing aircraft as well as helicopters and other aircraft with powered rotors, such as cyclogyros/cyclocopters and tiltrotors. Some VTOL aircraft can operate in other modes as well, such as CTOL, STOL, or STOVL. Others, such as some helicopters, can only operate by VTOL, due to the aircraft lacking landing gear that can handle horizontal motion. VTOL is a subset of V/STOL. Some lighter-than-air aircraft also qualify as VTOL aircraft, as they can hover, takeoff, and land with vertical approach/departure profiles.
A vertical and/or short take-off and landing (V/STOL) aircraft is an airplane able to take-off or land vertically or on short runways. Vertical takeoff and landing (VTOL) aircraft are a subset of V/STOL craft that do not require runways at all. Generally, a V/STOL aircraft needs to be able to hover. Helicopters are not considered under the V/STOL classification as the classification is only used for aeroplanes, aircraft that achieve lift (force) in forward flight by planing the air, thereby achieving speed and fuel efficiency that is typically greater than the capability of helicopters.
The Bell X-22 is an American V/STOL X-plane with four tilting ducted fans. Takeoff was to selectively occur either with the propellers tilted vertically upwards, or on a short runway with the nacelles tilted forward at approximately 45°. Additionally, the X-22 was to provide more insight into the tactical application of vertical takeoff troop transporters such as the preceding Hiller X-18 and the X-22's successor, the Bell XV-15. Another program requirement was a true airspeed in level flight of at least 525 km/h.
The Curtiss-Wright X-19, company designation Model 200, was an American experimental tiltrotor aircraft of the early 1960s. It was noteworthy for being the last aircraft of any kind manufactured by Curtiss-Wright.
The Canadair CL-84 "Dynavert", designated by the Canadian Forces as the CX-131, was a V/STOL turbine tiltwing monoplane designed and manufactured by Canadair between 1964 and 1972. Only four of these experimental aircraft were built with three entering flight testing. Two of the CL-84s crashed due to mechanical failures, with no fatalities occurring in either of the accidents. Despite the fact that the CL-84 was successful in the experimental and operational trials carried out between 1972 and 1974 however, none of the prospective customers placed any orders for the type.
The Ryan XV-5 Vertifan was a jet-powered V/STOL experimental aircraft in the 1960s. The United States Army commissioned the Ryan VZ-11-RY in 1961, along with the Lockheed VZ-10 Hummingbird. It successfully proved the concept of ducted lift fans, but the project was cancelled after multiple fatal crashes unrelated to the lift system.
The Lockheed XV-4 Hummingbird was a U.S. Army project to demonstrate the feasibility of using VTOL for a surveillance aircraft carrying target-acquisition and sensory equipment. It was designed and built by the Lockheed Corporation in the 1960s, one of many attempts to produce a V/STOL vertical take off/landing jet. Both prototype aircraft were destroyed in accidents.
The Rockwell XFV-12 was a prototype supersonic United States Navy fighter which was built in 1977. The XFV-12 design attempted to combine the Mach 2 speed and AIM-7 Sparrow armament of the McDonnell Douglas F-4 Phantom II in a VTOL fighter for the small Sea Control Ship which was under study at the time. On paper, it looked superior to the subsonic Hawker Siddeley Harrier attack fighter. However, its inability to meet performance requirements terminated the program.
The Fairey Jet Gyrodyne is a British experimental compound autogyro built by the Fairey Aviation Company that incorporated helicopter, gyrodyne and autogyro characteristics. The Jet Gyrodyne was the subject of a Ministry of Supply (MoS) research contract to gather data for the follow-up design, the Rotodyne.
The Ling-Temco-Vought (LTV) XC-142 was a tri-service tiltwing experimental aircraft designed to investigate the operational suitability of vertical/short takeoff and landing (V/STOL) transports. An XC-142A first flew conventionally on 29 September 1964, and on 11 January 1965, it completed its first transitional flight by taking off vertically, changing to forward flight and finally landing vertically. Its service sponsors pulled out of the program one by one, and it eventually ended due to a lack of interest after demonstrating its capabilities successfully.
The Hunting H.126 was an experimental aircraft designed and built by British aviation company Hunting Aircraft.
A powered lift aircraft takes offs and lands vertically under engine power but uses a fixed wing for horizontal flight. Like helicopters, these aircraft do not need a long runway to take off and land, but they have a speed and performance similar to standard fixed-wing aircraft in combat or other situations.
The Anderson Greenwood AG-14 is a two-seat utility aircraft developed in the United States shortly after World War II. It is an all-metal, shoulder-wing monoplane of pod-and-boom configuration, equipped with a pusher propeller, side-by-side seating and fixed tricycle undercarriage.
The Stipa-Caproni, also generally called the Caproni Stipa, was an experimental Italian aircraft designed in 1932 by Luigi Stipa (1900–1992) and built by Caproni. It featured a hollow, barrel-shaped fuselage with the engine and propeller completely enclosed by the fuselage—in essence, the whole fuselage was a single ducted fan. Although the Regia Aeronautica was not interested in pursuing development of the Stipa-Caproni, its design influenced the development of jet propulsion.
The channel wing is an aircraft wing principle developed by Willard Ray Custer in the 1920s. The most important part of the wing consists of a half-tube with an engine placed in the middle, driving a propeller placed at the rear end of the channel formed by the half-tube.
The Mississippi State University XV-11A Marvel was an experimental American STOL research aircraft of the 1960s. The MARVEL (Mississippi Aerophysics Research Vehicle with Extended Latitude) was a single-engined pusher monoplane fitted with a boundary layer control system. The first all-composite aircraft, it carried out its initial program of research on behalf of the US Army in the late 1960s, and was rebuilt in the 1980s as a proof-of-concept for a utility aircraft.
The Curtiss-Wright VZ-7 was a VTOL quadrotor helicopter aircraft designed by the Curtiss-Wright company for the US Army. Like the Chrysler VZ-6 and the VZ-8 Airgeep it was to be a "flying jeep".
The Dornier Do 29 was an experimental aircraft developed by Dornier Flugzeugwerke and the Deutsche Versuchsanstalt für Luftfahrt in the 1950s, used to test a tilting-propeller system for short takeoff and landing (STOL) aircraft. The concept was proved to be successful in flight testing; however, no further development of the system or aircraft was proceeded with, and at the conclusion of its test program the Do 29 was retired.
The Bede XBD-2 was an experimental short takeoff and landing (STOL) aircraft, with several novel features such as structural use of glass-fibre and aluminium honeycomb, a suction boundary layer control (BLC) system and fuselage-mounted twin engines driving a pusher configuration, shrouded single propeller. The sole example flew in the early 1960s in the United States.
The General Dynamics–Boeing AFTI/F-111A Aardvark was a research aircraft modified from a General Dynamics F-111 Aardvark to test a Boeing-built supercritical mission adaptive wing (MAW). This MAW, in contrast to standard control surfaces, could smoothly change the shape of its airfoil in flight.
