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{{Short description|Aircraft takeoff and landing class}}{{Redirect|Heli-Jet|the helicopter airline based in Vancouver, British Columbia, Canada|Helijet}}{{for|rocket vertical takeoff and landing|VTVL}}{{Refimprove|date=September 2017}}
{{Use dmy dates|date=October 2020}}
[[File:BAe Harrier GR9 ZG502 landing arp.jpg|thumb|right|[[RAF]] Harrier GR9 arrives at [[RIAT]] 2008]]
[[File:US Navy 080220-N-5180F-015 A Marine Corps MV-22 Osprey prepares to land aboard the amphibious assault ship USS Nassau (LHA 4).jpg|thumb|right|A U.S. Marine Corps [[Bell-Boeing V-22 Osprey|MV-22 Osprey]] prepares to land aboard a ship.]]
A '''vertical and/or short take-off and landing''' ('''V/STOL''') aircraft is an [[airplane]] able to [[takeoff and landing|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)|lift]] in forward flight by planing the air, thereby achieving speed and [[fuel efficiency]] that is typically greater than the capability of helicopters.

The main advantage of V/STOL aircraft is closer basing to the enemy, which reduces response time and tanker support requirements. In the case of the [[Falklands War]], it also permitted high-performance fighter air cover and ground attack without a large aircraft carrier equipped with [[aircraft catapult]]. V/STOL was developed to allow fast jets to be operated from clearings in forests, from very short runways, and from small [[aircraft carrier]]s that would previously only have been able to carry [[helicopter]]s. 

A rolling takeoff, sometimes with a ramp ([[ski-jump (aviation)|ski-jump]]), reduces the amount of thrust required to lift an aircraft from the ground (compared with vertical takeoff), and hence increases the payload and range that can be achieved for a given thrust. For instance, the Harrier is incapable of taking off vertically with full weapons and fuel load.  Hence V/STOL aircraft generally use a runway if it is available. In other words, short takeoff and vertical landing (STOVL) or conventional takeoff and landing ([[CTOL]]) operation is preferred to vertical takeoff and landing (VTOL) operation.[[File:FA2_Sea_Harrier_Launches_from_HMS_Illustrious_MOD_45139505.jpg|thumb|A [[British Aerospace Sea Harrier|Sea Harrier]] launches from the flight deck of [[HMS Illustrious (R06)|HMS ''Illustrious'']] in 2001]]On [[Aircraft carrier|aircraft carriers]], non-catapult-assisted fixed-wing short takeoffs are accomplished with the use of [[thrust vectoring]], which may also be used in conjunction with a runway "[[Ski-jump (aviation)|ski-jump]]". There are 16 aircraft carriers that operate these STOVL aircraft: United States (9), Japan (2), United Kingdom (2), Italy (2), and Spain (1). Use of STOVL tends to allow aircraft to carry a larger payload compared to [[VTOL|vertical take-off and landing]] (VTOL), while still only requiring a short runway. The most famous examples are the [[Hawker Siddeley Harrier]] and the [[British Aerospace Sea Harrier|BAe Sea Harrier]]. Although technically a V/STOL aircraft, they are operationally STOVL aircraft due to the extra weight carried at take-off for fuel and armaments. The same is true of the B variant of the [[Lockheed Martin F-35 Lightning II]], which demonstrated VTOL capability in test flights but is operationally a STOVL.<ref>[http://www.bellhelicopter.com/en/aircraft/military/pdf/V-22_64214_pGuide.pdf V-22 Osprey Pocket Guide] {{webarchive|url=https://web.archive.org/web/20101229211428/http://www.bellhelicopter.com/en/aircraft/military/pdf/V-22_64214_pGuide.pdf|date=29 December 2010}}. Bell Boeing, 2007. Retrieved 17 April 2010.</ref>

=== VTOL ===
Vertical take-off and landing (VTOL) is a subset of V/STOL. This classification can include a variety of types of [[aircraft]] as well as [[thrust-vectoring]] [[fixed-wing aircraft]] and other hybrid aircraft with powered [[Helicopter rotor|rotors]] such as [[Cyclogyro|cyclogyros]] and [[Gyrodyne|gyrodynes]].<ref>{{Cite journal |last=Laskowitz |first=I. B. |date=1961 |title=Vertical Take-Off and Landing (Vtol) Rotorless Aircraft with Inherent Stability |url=http://dx.doi.org/10.1111/j.1749-6632.1961.tb30485.x |journal=Annals of the New York Academy of Sciences |volume=93 |issue=1 |pages=3–24 |bibcode=1961NYASA..93....3L |doi=10.1111/j.1749-6632.1961.tb30485.x |issn=0077-8923 |s2cid=84160729 |url-access=subscription}}</ref>
[[File:Royal_International_Air_Tattoo_2018_MOD_45164432.jpg|thumb|An [[Royal Air Force|RAF]] [[Lockheed Martin F-35 Lightning II|F-35B Lightning II]] demonstrating a vertical landing]]
Some VTOL aircraft can operate in other modes as well, such as [[CTOL]] (conventional take-off and landing), [[STOL]] (short take-off and landing), or STOVL (short take-off and vertical landing). Others, such as some helicopters, can only operate as VTOL, due to the aircraft's lack of [[landing gear]] that can handle [[taxiing]]. Some [[Aerostat|lighter-than-air aircraft]] also qualify as VTOL aircraft, as they can hover, take off and land with vertical approach/departure profiles.<ref>{{cite web |first=Bill | last=Virgin |date=December 2017 |title=Plimp, a Plane-Blimp Hybrid, Is Looking to Disrupt the Drone Market - Seattle brothers James and Joel Egan are adding a new airship to the drone market, and it could be available as soon as next year. |url=https://www.seattlebusinessmag.com/technology/plimp-plane-blimp-hybrid-looking-disrupt-drone-market |access-date=16 November 2021 |publisher=Seattle Business Magazine}}</ref>

Electric vertical takeoff and landing aircraft, or [[EVTOL|eVTOLs]], are being developed along with more autonomous flight control technologies and mobility-as-a-service (MaaS) to enable advanced air mobility (AAM), that could include on-demand air taxi services, regional air mobility, freight delivery, and [[personal air vehicles]] (PAVs).<ref>Le Bris, G. et al. (2022). "ACRP Research Report 236: Preparing Your Airport for Electric Aircraft and Hydrogen Technologies". Transportation Research Board, Washington, DC: https://nap.nationalacademies.org/catalog/26512/preparing-your-airport-for-electric-aircraft-and-hydrogen-technologies</ref>

Besides the ubiquitous helicopters, there are currently two types of VTOL aircraft in military service: [[tiltrotor]] aircraft, such as the [[Bell Boeing V-22 Osprey]], and thrust-vectoring airplanes, such as the [[Harrier jump jet|Harrier family]] and new [[Lockheed Martin F-35 Lightning II#F-35B|F-35B Lightning II]] [[Joint Strike Fighter]] (JSF). In the civilian sector, currently only helicopters are in general use (some other types of commercial VTOL aircraft have been proposed and are under development {{as of|2017|lc=yes}}). Generally speaking, VTOL aircraft capable of STOVL use the latter wherever possible, since it typically significantly increases takeoff weight, range, or payload compared to pure VTOL.<ref name="Khurana p. 133">{{cite book |url=https://books.google.com/books?id=ESWo4Zl5g1IC |title=Aviation Management: Global Perspectives |vauthors=Khurana KC |date=2009 |publisher=Global India Publications |isbn=9789380228396 |page=133}}</ref>

== History ==
[[File:LiftThrust1.PNG|thumb|Comparison of lift and thrust for various aircraft]]
Of dozens of V/STOL designs tried from the 1950s to 1980s, only the subsonic Hawker Siddeley Harrier and Yak-38 Forger reached operational status, with the Forger being withdrawn after the fall of the [[Soviet Union]].

=== Props, proprotors, and advanced rotorcraft ===
{{see also|Helicopter#History|Tiltrotor#History}}
The idea of vertical flight has been around for thousands of years, and sketches for a VTOL (helicopter) show up in [[Leonardo da Vinci]]'s sketch book. Manned VTOL aircraft, in the form of primitive helicopters, first flew in 1907, but would take until after World War Two to be perfected.<ref>Yefim Gordon, The History of VTOL, page 28</ref><ref>John Whiteclay Chambers, The Oxford Companion to American Military History, Oxford University Press, USA, 1999, page 748</ref>

In addition to [[helicopter]] development, many approaches have been tried to develop practical aircraft with vertical take-off and landing capabilities, including [[Henry Berliner]]'s 1922–1925 experimental horizontal-rotor fixed-wing aircraft, and [[Nikola Tesla]]'s 1928 patent, and George Lehberger's 1930 patent for relatively impractical VTOL fixed wing airplanes with tilting engines.<ref>{{patent|us|1655113}}</ref><ref>{{Cite web |last=Rayl |first=A. J. S. |title=Nikola Tesla's Curious Contrivance |url=https://www.airspacemag.com/history-of-flight/nikola-teslas-curious-contrivance-10187565/ |access-date=2021-04-29 |website=Air & Space Magazine |language=en}}</ref><ref name="globalsecurity.org">{{Cite web |title=Tiltrotor |url=https://www.globalsecurity.org/military/systems/aircraft/tiltrotor.htm |access-date=2019-10-20 |website=www.globalsecurity.org}}</ref> In the late 1930s, British aircraft designer [[L. E. Baynes|Leslie Everett Baynes]] was issued a patent for the [[Baynes Heliplane]], another tiltrotor aircraft. In 1941, German designer [[Heinrich Focke]]'s began work on the [[Focke-Achgelis Fa 269]], which had two rotors that tilted downward for vertical takeoff, but wartime bombing halted development.<ref name="globalsecurity.org" />
[[File:Convair_XFY-1_Pogo_2.jpg|thumb|[[Convair XFY-1 Pogo]] in vertical flight]]
In May 1951, both [[Lockheed Corporation|Lockheed]] and [[Convair]] were awarded contracts in the attempt to design, construct, and test two experimental VTOL fighters. Lockheed produced the [[Lockheed XFV|XFV]], and Convair producing the [[Convair XFY Pogo]]. Both experimental programs proceeded to flight status and completed test flights 1954–1955, when the contracts were cancelled.<ref>Allen 2007, pp. 13–20.</ref> Similarly, the [[Ryan X-13 Vertijet]] flew a series of test flights between 1955 and 1957, but also suffered the same fate.<ref>{{Cite magazine |date=1957-05-20 |title=The new Vertijet's straight-up flight: X-13 takes off like a rocket, lands tailfirst |url={{google books |plainurl=y |id=JD8EAAAAMBAJ|page=142}} |magazine=Life |publisher=Time Inc |page=136 |language=en}}</ref>

In 1962, Lockheed built the [[Lockheed XV-4 Hummingbird|XV-4 Hummingbird]] for the [[U.S. Army]]. It sought to "augment" available thrust by injecting the engine exhaust into an ejector pump in the fuselage. First flying vertically in 1963, it suffered a fatal crash in 1964. It was converted into the XV-4B Hummingbird for the [[U.S. Air Force]] as a testbed for separate, vertically mounted lift engines, similar to those used in the [[Yakovlev Yak-38]] 'Forger'. That plane flew and later crashed in 1969.<ref name="x-planes">Jim Winchester, ''X-Planes and Prototypes'', Barnes and Noble Books</ref> The [[Ryan XV-5 Vertifan]], which was also built for the U.S. Army at the same time as the Hummingbird, experimented with gas-driven lift fans. That plane used fans in the nose and each wing, covered by doors which resembled half garbage can lids when raised. However, it crashed twice, and proved to generate a disappointing amount of lift, and was difficult to transition to horizontal flight.

[[Rockwell International]] built, and then abandoned, the [[Rockwell XFV-12]] supersonic fighter which had an unusual wing which opened up like [[Window blind|window blinds]] to create an ejector pump for vertical flight. It never generated enough lift to get off the ground despite developing 20,000 [[Pound-force|lbf]] of thrust. The French had a nominally Mach 2 [[Dassault Mirage IIIV]] fitted with no less than 8 lift engines that flew (and crashed), but did not have enough space for fuel or payload for combat missions. The German [[EWR VJ 101]] used swiveling engines mounted on the wingtips with fuselage mounted lift engines, and the VJ 101C X1 reached supersonic flight (Mach 1.08) on 29 July 1964. The supersonic [[Hawker Siddeley P.1154]], which competed with the Mirage IIIV for use in NATO, was cancelled even as the aircraft were being built.[[File:Xv-15_inflight.jpg|thumb|[[Bell XV-15]]]]
[[NASA]] has flown other VTOL craft such as the [[Bell XV-15]] research craft (1977), as have the [[Soviet Navy]] and ''[[German Air Force|Luftwaffe]]''. [[Sikorsky Aircraft Corporation|Sikorsky]] tested an aircraft dubbed the [[Sikorsky S-72|X-Wing]], which took off in the manner of a helicopter. The rotors would become stationary in mid-flight, and function as wings, providing lift in addition to the static wings. [[Boeing X-50]] is a [[Canard Rotor/Wing]] prototype that utilizes a similar concept.<ref>{{Cite web |last=Simonsen |first=Erik |title=Another one for the X files: The Boeing Canard Rotor/Wing demonstrator officially becomes X-50A |url=http://www.boeing.com/news/frontiers/archive/2002/may/ts_pw.html |access-date=2021-04-29 |website=www.boeing.com}}</ref>
[[File:Fairey_Jet_Gyrodyne-1.jpg|thumb|[[Fairey Jet Gyrodyne]]]]
A different British VTOL project was the [[gyrodyne]], where a rotor is powered during take-off and landing but which then freewheels during flight, with separate propulsion engines providing forward thrust. Starting with the [[Fairey Jet Gyrodyne|Fairey Gyrodyne]], this type of aircraft later evolved into the much larger twin-engined [[Fairey Rotodyne]], that used [[Tipjet|tipjets]] to power the rotor on take-off and landing but which then used two [[Napier Eland]] [[Turboprop|turboprops]] driving conventional propellers mounted on substantial wings to provide propulsion, the wings serving to unload the rotor during horizontal flight. The Rotodyne was developed to combine the efficiency of a fixed-wing aircraft at cruise with the VTOL capability of a helicopter to provide short-haul airliner service from city centres to airports.
[[File:Aircraft.osprey.678pix.jpg|thumb|U.S. Marines jump from a [[Bell-Boeing V-22 Osprey]], the first production [[tiltrotor]] aircraft]]
[[File:CanadairCL-84DynavertSerialCX8402.jpg|thumb|[[Canadair CL-84 Dynavert]] CL-84-1 (''CX8402'') on display at the [[Canada Aviation and Space Museum]] in Ottawa, Ontario]]
The [[Canadair CL-84 Dynavert|CL-84 Dynavert]] was a Canadian V/STOL turbine tilt-wing monoplane designed and manufactured by [[Canadair]] between 1964 and 1972. The Canadian government ordered three updated CL-84s for military evaluation in 1968, designated the CL-84-1. From 1972 to 1974, this version was demonstrated and evaluated in the United States aboard the aircraft carriers USS ''Guam'' and USS ''Guadalcanal'', and at various other centres.<ref>{{Cite book |last=Khurana |first=K. C. |url=https://books.google.com/books?id=ESWo4Zl5g1IC&pg=PA134 |title=Aviation Management: Global Perspectives |date=2009 |publisher=Global India Publications |isbn=978-93-80228-39-6 |page=134}}</ref> These trials involved military pilots from the United States, the United Kingdom, and Canada. During testing, two of the CL-84s crashed due to mechanical failures, but no loss of life occurred as a result of these accidents. No production contracts resulted.<ref>Boniface 2000, p. 74.</ref>

Although tiltrotors such as the [[Focke-Achgelis Fa 269]] of the mid-1940s and the Centro Técnico Aeroespacial "Convertiplano" of the 1950s reached testing or mock-up stages, the [[Bell-Boeing V-22 Osprey]] is considered the world's first production [[tiltrotor]] aircraft. It has one three-bladed [[proprotor]], [[turboprop]] engine, and transmission [[nacelle]] mounted on each wingtip. The Osprey is a multi-mission aircraft with both a vertical takeoff and landing (VTOL) and short takeoff and landing capability ([[STOL]]). It is designed to perform missions like a conventional [[helicopter]] with the long-range, high-speed cruise performance of a [[turboprop]] aircraft. The FAA classifies the Osprey as a model of [[powered lift]] aircraft.<ref>Norton 2004, pp. 6–9, 95–96.</ref>

Attempts were made in the 1960s to develop a commercial passenger aircraft with VTOL capability. The [[Hawker Siddeley]] Inter-City Vertical-Lift proposal had two rows of lifting fans on either side. However, none of these aircraft made it to production after they were dismissed as too heavy and expensive to operate.<ref name="intercity">{{Cite web |title=BAE animates mothballed Intercity Vertical-Lift Aircraft |url=https://www.aerospace-technology.com/features/featurebae-mothballed-intercity-vertical-lift-aircraft |access-date=2021-04-29 |website=www.aerospace-technology.com}}</ref><ref name="baesystems">{{Cite web |title=Forgotten 1960s 'Thunderbirds' projects brought to life |url=https://www.baesystems.com/en/home |access-date=2021-04-29 |website=BAE Systems {{!}} International |language=en}}</ref>

In 1983, the Defense Advanced Research Projects Agency ([[DARPA]]) initiated the Advanced STOVL (ASTOVL) program to develop a supersonic STOVL fighter (SSF) to replace the Harrier for the U.S. Marine Corps and the U.K. Royal Navy. Several propulsion methods were explored under ASTOVL and assigned to different contractors for research and development. These include the Shaft-Driven Lift Fan (SDLF) by [[Lockheed Corporation|Lockheed]] which had a forward [[lift fan]] powered by a shaft connected to the main engine's low-pressure spool and engaged by a clutch, the Lift-Plus-Lift/Cruise (LPLC) by [[Northrop Corporation|Northrop]] (later [[Northrop Grumman]]) which had a separate dedicated lift engine alongside the main engine, and the Gas-Driven Lift Fan (GDLF) by [[McDonnell Douglas]] that used the main engine bleed air to power a lift fan; all methods had an aft vectoring nozzle for the main engine.<ref>{{cite web |last= |first= |date=20 February 1996 |title=As McDonnell Douglas revises JAST design |url=https://www.flightglobal.com/as-mcdonnell-douglas-revises-jast-design/11174.article |work=Flight International}}</ref>

ASTOVL would continue under the [[Common Affordable Lightweight Fighter]] (CALF) program, which eventually became part of the [[Joint Strike Fighter program]]; the [[Lockheed Martin X-35|Lockheed Martin X-35B]] with the SDLF was eventually selected for full-scale development in 2001, with the production aircraft for operational service becoming the F-35B with the [[Pratt & Whitney F135|F135-PW-600]] engine. [[NASA]] uses the [[abbreviation]] SSTOVL for Supersonic Short Take-Off / Vertical Landing,<ref>{{cite book |author=Barbara S. Esker |title=Performance characteristics of a one-third-scale, vectorable ventral nozzle for SSTOVL aircraft |date=1990 |publisher=NASA |isbn=9780760770917 |location=[Washington, D.C.] |oclc=24990569 |ol=17630526M}}</ref> and as of 2012, the X-35B/F-35B are the only aircraft to conform with this combination within one flight.<ref>[https://www.pbs.org/wgbh/nova/transcripts/3004_xplanes.html "X-planes".] ''PBS: Nova transcript''. Retrieved 9 January 2010.</ref><ref name="f-35b supersonic">Cavas, Christopher P. [http://www.marinecorpstimes.com/news/2010/06/dn_jsf_supersonic_061410/ "F-35B STOVL fighter goes supersonic."] {{webarchive|url=https://web.archive.org/web/20110714034433/http://www.marinecorpstimes.com/news/2010/06/dn_jsf_supersonic_061410/|date=14 July 2011}} ''[[Marine Corps Times]]'', 15 June 2010. Retrieved 15 June 2010.</ref>

In 2018, Opener Aero demonstrated an electrically powered fixed-wing VTOL aircraft, the [[Pivotal BlackFly|Blackfly]], which the manufacturer claims is the world's first ultralight fixed-wing, all-electric, VTOL aircraft.<ref name="Oconnor12Jul18">{{cite web |last=O'Connor |first=Kate |date=12 July 2018 |title=Opener Reveals Ultralight eVTOL |url=https://www.avweb.com/avwebflash/news/Opener-Reveals-Ultralight-eVTOL-231121-1.html |url-status=dead |archive-url=https://web.archive.org/web/20230127092714/https://www.avweb.com/avwebflash/news/Opener-Reveals-Ultralight-eVTOL-231121-1.html |archive-date=27 January 2023 |access-date=13 July 2018 |work=AVweb}}</ref>
[[File:Schiebel_CAMCOPTER_S-100.jpg|thumb|A [[Schiebel Camcopter S-100]], a modern VTOL [[unmanned aerial vehicle]]]]
In the 21st century, unmanned drones are becoming increasingly commonplace. Many of these have VTOL capability, especially the [[quadcopter]] type.<ref>{{Cite journal |last1=Woodbridge |first1=Ewan |last2=Connor |first2=Dean T. |last3=Verbelen |first3=Yannick |last4=Hine |first4=Duncan |last5=Richardson |first5=Tom |last6=Scott |first6=Thomas B. |date=2023-06-28 |title=Airborne gamma-ray mapping using fixed-wing vertical take-off and landing (VTOL) uncrewed aerial vehicles |journal=Frontiers in Robotics and AI |volume=10 |doi=10.3389/frobt.2023.1137763 |issn=2296-9144 |pmc=10337992 |pmid=37448876 |doi-access=free}}</ref>

=== Jet lift ===
[[File:Ryan_X-13.jpg|thumb|The Ryan X-13]]

==== Tail-sitters ====
In 1947, the [[Ryan X-13 Vertijet]], a [[tailsitter]] design, was ordered by the US Navy, who then further issued a proposal in 1948 for an aircraft capable of VTOL aboard platforms mounted on the afterdecks of conventional ships. Both [[Convair]] and [[Lockheed Corporation|Lockheed]] competed for the contract but in 1950, the requirement was revised, with a call for a research aircraft capable of eventually evolving into a VTOL ship-based convoy escort fighter.{{fact|date=November 2025}}

At the end of 1958, the French [[SNECMA Coléoptère]], a tailsitter [[Closed wing|annular wing]] design, performed its maiden flight. However the sole prototype was destroyed on its ninth flight in 1959, and financing was never sourced for a second prototype.{{fact|date=November 2025}}

==== Conventional design ====
[[File:Rolls-Royce_Thrust_Measuring_Rig_science_museum.jpg|thumb|"Flying Bedstead"- Rolls-Royce Thrust Measuring Rig]]
Another more influential early functional contribution to VTOL was [[Rolls-Royce Limited|Rolls-Royce]]'s [[Rolls-Royce Thrust Measuring Rig|Thrust Measuring Rig]] ("flying bedstead") of 1953. This led to the first VTOL engines as used in the first British VTOL aircraft, the [[Short SC.1]] (1957), Short Brothers and Harland, Belfast which used four vertical lift engines with a horizontal one for forward thrust.
[[File:Short_SC.1.jpg|thumb|The Short SC.1 a VTOL delta aircraft]]
The [[Short SC.1]] was the first British fixed-wing VTOL aircraft. The SC.1 was designed to study the problems with VTOL flight and the transition to and from forward flight. The SC.1 was designed to meet a Ministry of Supply (MoS) request for tender (ER.143T) for a vertical take-off research aircraft issued in September 1953. The design was accepted by the ministry and a contract was placed for two aircraft (XG900 and XG905) to meet Specification ER.143D dated 15 October 1954. The SC.1 was also equipped with the first "fly-by-wire" control system for a VTOL aircraft. This permitted three modes of control of the aerodynamic surfaces or the nozzle controls.

The [[Republic Aviation]] [[Republic AP-100|AP-100]] was a prototype VTOL 6x [[General Electric J85]] turbojet-engined nuclear-capable strike fighter concept designed by [[Alexander Kartveli]] that had three ducted fans in the centre of its fuselage and tail as a possible contender for the [[TFX Program]].<ref>Project Hummingbird (Technical Report) A Technical Summary and Compilation of Characteristics and Specifications on Steep-Gradient Aircraft, Volume 88, April 1961. By United States Federal Aviation Agency. Page 143–144, Figure 175.</ref><ref>Air Progress History of Aviation Spring 1961 edition</ref><ref>Aviation Week and Space Technology, Lift-Fan Tests Show VTOL Potential. August 8, 1960</ref> Another design was the A400 AVS that used variable-geometry wings but was found too complicated; however, it led to the development of the [[AFVG]], which in turn helped the development of the [[Panavia Tornado]].
[[File:Yak-38_Lift_Engines_NT.PNG|thumb|The [[Soviet Union]]'s VTOL aircraft, the [[Yakovlev Yak-38]]]]
The [[Yakovlev Yak-38]] was a [[Soviet Navy]] VTOL aircraft intended for use aboard their light carriers, cargoships, and capital ships. It was developed from the [[Yakovlev Yak-36]] experimental aircraft in the 1970s. Before the Soviet Union broke up, a supersonic VTOL aircraft was developed as the Yak-38's successor, the [[Yakovlev Yak-141|Yak-141]], which never went into production.<ref>{{Cite web |date=16 July 2008 |title=Vertical take-off/landing aircraft: Yak-38 |url=http://www.yak.ru/ENG/FIRM/HISTMOD/yak-38.php |access-date=2021-04-29 |website=www.yak.ru |publisher=[[Yakovlev|Yakovlev Design Bureau]]}}</ref>
[[File:Aircraft_VJ101C_top.jpg|thumb|A German V/[[STOL]] [[EWR VJ 101|VJ101]] on display at the [[Deutsches Museum]], [[Munich, Germany]]]]
[[File:Do-31_2.jpg|thumb|[[Dornier Do 31|Do 31 E3]] on display at the [[Deutsches Museum]], Germany]]
In the 1960s and early 1970s, Germany planned three different VTOL aircraft. One used the [[Lockheed F-104 Starfighter]] as a basis for research for a V/STOL aircraft. Although two models (X1 and X2) were built, the project was canceled due to high costs and political problems as well as changed needs in the [[German Air Force]] and NATO. The [[EWR VJ 101]]C did perform free VTOL take-offs and landings, as well as test flights beyond mach 1 in the mid- and late 60s. One of the test aircraft is preserved in the [[Deutsches Museum]] in Munich, Germany, another outside Friedrichshafen Airport. The others were the VFW-Fokker [[VFW VAK 191B|VAK 191B]] light fighter and reconnaissance aircraft, and the [[Dornier Do 31]]E-3 (troop) transport.<ref>Jackson 1976, p. 143.</ref>

The [[LLRV]] was a [[spacecraft]] simulator for the Apollo lunar lander.<ref>{{Cite web |title=NASA - NASA Dryden Technology Facts - Lunar Landing Research Vehicle |url=https://www.nasa.gov/centers/dryden/about/Organizations/Technology/Facts/TF-2004-08-DFRC.html |url-status=dead |archive-url=https://web.archive.org/web/20181223163609/https://www.nasa.gov/centers/dryden/about/Organizations/Technology/Facts/TF-2004-08-DFRC.html |archive-date=2018-12-23 |access-date=2021-04-29 |website=www.nasa.gov |language=en}}</ref> It was designed to mimic the flight characteristics of the [[Apollo Lunar Module|lunar exploration module]] (LEM), which had to rely on a reaction engine to land on the Moon.

The idea of using the same engine for vertical and horizontal flight by altering the path of the thrust was conceived by [[Michel Wibault]].<ref name="Pegasus">{{cite book |last1=Dow |first1=Andrew |url=https://books.google.com/books?id=qTLAAwAAQBAJ |title=Pegasus: The Heart of the Harrier |date=2009 |publisher=Pen & Sword Aviation |isbn=978-1-84884-042-3 |location=Barnsley, South Yorkshire, UK |pages=29–46 |access-date=13 June 2020}}</ref> It led to the [[Bristol Siddeley Pegasus]] engine which used four rotating [[Nozzle|nozzles]] to direct thrust over a range of angles.<ref>{{cite book |title=Basics of Aeronautics |chapter=Airfoil |access-date=24 May 2015 |chapter-url=http://www.engineering108.com/Data/Engineering/aeronautical_engineering/Basics-of-Aeronautics.pdf}}</ref> This was developed side-by-side with an airframe, the [[Hawker P.1127]], which became subsequently the Kestrel and then entered production as the [[Hawker Siddeley Harrier]], though the supersonic [[Hawker Siddeley P.1154]] was canceled in 1965. The French in competition with the P.1154 had developed a version of the [[Dassault Mirage III]] capable of attaining [[Mach Number|Mach]] 1. The [[Dassault Mirage IIIV]] achieved transition from vertical to horizontal flight in March 1966, reaching Mach 1.3 in level flight a short time later.

==== V/STOL ====
[[File:INAS_300_Sea_Harrier_vertical_landing_on_a_carrier.JPG|right|thumb|Landing of [[Harrier jump jet]] with [[Indian Naval Air Arm]]]]
The Harrier is usually flown in STOVL mode, which enables it to carry a higher fuel or weapon load over a given distance.<ref name="Khurana p. 133" /> In V/STOL, the aircraft moves horizontally along the runway before taking off using vertical thrust. This gives aerodynamic lift as well as thrust lift and permits taking off with heavier loads and is more efficient. When landing, the aircraft is much lighter due to the loss of propellant weight, and a controlled vertical landing is possible. An important aspect of Harrier STOL operations aboard naval carriers is the "ski jump" raised forward deck, which gives the craft additional vertical momentum at takeoff.<ref>{{cite web |date=31 October 2019 |title=The genius of the naval jump-jet |url=https://www.maritimefoundation.uk/publications/maritime-2019/the-genius-of-the-naval-jump-jet/ |access-date=20 January 2020 |publisher=The Maritime Foundation}}</ref>

The March 1981 cover of [[Popular Science]] showed three illustrations for its "Tilt-engine V/STOL – speeds like a plane, lands like a copter" front-page feature story;<ref>{{cite magazine |date=March 1981 |title=Tilt-engine V/STOL - speeds like a plane, lands like a copter |url=https://books.google.com/books?id=z7nkfLrLoMsC |magazine=[[Popular Science]] |page=3}}</ref> a followup story was part of the April 2006 issue that mentioned "the fuel-consumption and stability problems that plagued earlier plane/copter."<ref>{{cite magazine |date=April 2006 |title=V/STOL |url=https://books.google.com/books?id=MY3SEwT-K0oC |magazine=Popular Science |page=118}}</ref>

Retired from the British [[Royal Navy]] in 2006,<ref>{{cite web |date=28 March 2006 |title=Hover and out: UK Royal Navy retires the Sea Harrier |url=https://www.flightglobal.com/hover-and-out-uk-royal-navy-retires-the-sea-harrier/66527.article |access-date=20 January 2020 |website=FlightGlobal}}</ref> the [[Indian Navy]] continued to operate [[Sea Harrier|Sea Harriers]] until 2016,<ref>{{cite web |last1=Raghuvanshi |first1=Vivek |date=21 March 2016 |title=Indian Navy Retires Sea Harriers |url=https://www.defensenews.com/naval/2016/03/21/indian-navy-retires-sea-harriers/ |access-date=20 January 2020 |website=Defense News}}</ref> mainly from its [[aircraft carrier]] {{ship|INS|Viraat}}. The latest version of the Harrier, the [[BAE Harrier II]], was retired in December 2010 after being operated by the British [[Royal Air Force]] and Royal Navy. The [[United States Marine Corps]] and the Italian and Spanish navies all continue to use the [[AV-8B Harrier II]], an American-British variant. Replacing the Harrier II/AV-8B in the air arms of the US and UK is the STOVL variant of the [[Lockheed Martin F-35 Lightning II]], the F-35B.<ref>{{cite web |last1=Roblin |first1=Sebastien |date=13 October 2018 |title=The Royal Navy Is Back (Thanks to the F-35 and Two New Aircraft Carriers) |url=https://nationalinterest.org/blog/buzz/royal-navy-back-thanks-f-35-and-two-new-aircraft-carriers-33416 |access-date=20 January 2020 |website=National Interest}}</ref>

==== Rockets ====
{{main|VTVL}}

[[SpaceX]] developed [[Falcon 9 prototypes|several prototypes of Falcon 9]] to validate various low-altitude, low-velocity engineering aspects of its [[SpaceX reusable launch system development program|reusable launch system development program]].<ref name="sfn20120709">{{cite news |date=2012-07-09 |title=Reusable rocket prototype almost ready for first liftoff |url=http://www.spaceflightnow.com/news/n1207/10grasshopper/ |access-date=2012-07-13 |newspaper=Spaceflight Now |quote=''SpaceX has constructed a half-acre concrete launch facility in McGregor, and the Grasshopper rocket is already standing on the pad, outfitted with four insect-like silver landing legs.''}}</ref> The first prototype, Grasshopper, made eight successful test<ref>{{cite web |date=10 March 2013 |title=Grasshopper Completes Highest Leap to Date |url=http://www.spacex.com/press.php?page=20130310 |url-status=dead |archive-url=https://web.archive.org/web/20130429060358/http://www.spacex.com/press.php?page=20130310 |archive-date=29 April 2013 |access-date=11 March 2013 |publisher=SpaceX.com}}</ref> flights in 2012–2013. It made its eighth, and final, test flight on October 7, 2013, flying to an altitude of {{convert|744|m}} before making its eighth successful VTVL landing.<ref name="sx20131012fb">{{cite web |date=12 October 2013 |title=Grasshopper flies to its highest height to date |url=https://www.facebook.com/SpaceX/posts/10153372146765131 |access-date=14 October 2013 |work=Social media information release |publisher=SpaceX |quote=''WATCH: Grasshopper flies to its highest height to date – 744 m (2441 ft) into the Texas sky.''}}</ref><ref>{{Citation |title=Grasshopper 744m Test {{!}} Single Camera (Hexacopter) |date=12 October 2013 |url=https://www.youtube.com/watch?v=9ZDkItO-0a4 |access-date=2021-04-29 |language=en}}</ref> This was the last scheduled test for the Grasshopper rig; next up will be low altitude tests of the Falcon 9 Reusable (F9R) development vehicle in Texas followed by high altitude testing in New Mexico.

On November 23, 2015, [[Blue Origin]]'s New Shepard booster rocket made the first successful vertical landing following an uncrewed suborbital test flight that reached space.<ref>{{cite web |date=November 24, 2015 |title=Blue Origin make historic rocket landing |url=https://www.blueorigin.com/news/news/blue-origin-makes-historic-rocket-landing |accessdate=November 24, 2015 |work=Blue Origin}}</ref> On December 21, 2015, [[SpaceX]] [[Falcon 9]] first stage made a successful landing after boosting 11 commercial satellites to [[low Earth orbit]] on [[Falcon 9 Flight 20]].<ref>{{Cite web |title=SpaceX Twitter post |url=https://twitter.com/spacex/status/679114269485436928 |access-date=2021-04-29 |website=Twitter |language=en}}</ref> These demonstrations opened the way for substantial reductions in space flight costs.

==Lists of V/STOL aircraft==
This is a partial list; there have been many designs for V/STOL aircraft.

===Vectored thrust===
* [[Hawker P.1127|Hawker P.1127/Kestrel]]/[[Harrier jump jet|Harrier]]; four rotating nozzles for vectored thrust of fan and jet exhaust.

===Tilt-jet===
* [[Bell XF-109]]
* [[Bell 65]]
* [[EWR VJ 101]]

===Tilt-rotor===
* [[AgustaWestland AW609]] (originally Bell 609)
* [[AgustaWestland Project Zero]] technology demonstrator
* [[Bell XV-3]]
* [[Bell XV-15]]
* [[Bell-Boeing V-22 Osprey]] (scale up of XV-15)
* [[Bell V-280 Valor]]

===Tilt-wing===
* [[Curtiss-Wright X-19]] – four rotating propellers, tilt-wing.
* [[Canadair CL-84 Dynavert]], two [[turboprop]] tilt-wing 
* [[LTV XC-142]] four-engine tilt-wing cross-shafted [[turboprop]]
* [[Bell X-22]] rotating ducted propellers. Small transport prototype. Slightly smaller than V-22 Osprey.
* [[Hiller X-18]]

===Separate thrust and lift===
* [[Dornier Do 31]] Jet transport with podded vector nozzles and lift engines
* [[Kamov Ka-22]]
* [[Lockheed XV-4 Hummingbird]]
* [[Dassault Balzac V]] (V stands for vertical and is a modified Mirage III)
* [[Dassault Mirage IIIV]] the first VTOL capable of supersonic flight (Mach 2.03 during tests)
* [[Fokker/Republic D-24 Alliance]]
* Ryan [[XV-5 Vertifan|XV-5]]. Fans in wings driven by engine exhaust gas.
* [[VFW VAK 191B]] Attack fighter similar to Harrier but supersonic dash speed, smaller wings and lift engines. Flown, but not operational.
* [[Yakovlev Yak-38]]
* [[Yakovlev Yak-141]]
* [[Short SC.1]]

===Supersonic===
Although many aircraft have been proposed and built, with a few being tested, the F-35B is the first and only supersonic V/STOL aircraft to have reached operational service, having entered service in 2016.<ref>[http://www.cqpolitics.com/wmspage.cfm?docID=news-000003175295 "Report: F-35 Work Falls Behind Two More Years."] {{Webarchive|url=https://web.archive.org/web/20090727083410/http://www.cqpolitics.com/wmspage.cfm?docID=news-000003175295 |date=2009-07-27 }} ''CQ Politics'', 23 July 2009.</ref>
* [[Bell D-188A]] Mach 2 swivelling engines, mockup stage
* [[EWR VJ 101]] Mach 2 fighter, flown to Mach 1.04 but not operational
* [[Dassault Mirage IIIV]] Delta wing Mach 2 fighter with lift engines, first VTOL capable of supersonic and Mach 2 flight (Mach 2.03 during tests), not operational
* Hawker Siddeley HS 138 Strike fighter with lift fans. It was not completed.
* [[Hawker Siddeley P.1017]] Lift engines with thrust vectoring. It was not completed.
* [[Hawker Siddeley P.1154]] M1.7 Supersonic Harrier. It was not completed.
* Hawker Siddeley P.1184-16 Dash 18
* Hawker Siddeley P.1217
* [[Republic AP-100]] strike fighter concept
* [[Convair Model 200]] Lift engines plus swivel tailpipe, not built
* [[Rockwell XFV-12]] Built with complex "window blind" wings but could not lift its own weight
* [[Yakovlev Yak-141]] Lift engines plus swivel tailpipe
* [[Lockheed Martin X-35|Lockheed Martin X-35B]] / [[Lockheed Martin F-35 Lightning II|F-35B]] uses a vectored-thrust tailpipe (the [[Pratt & Whitney F135]]) plus a shaft-driven [[Rolls-Royce LiftSystem|lifting fan]]. It is the first aircraft capable of demonstrating transition from short take-off to supersonic flight to vertical landing on the same sortie.<ref name="ss-hover">Kjelgaard, Chris (Senior Editor). [http://www.space.com/businesstechnology/071221-how-f-35b-stovl-propulsion-system-works.html "From Supersonic to Hover: How the F-35 Flies."] ''space.com,'' 21 December 2007.</ref>

== See also ==
<div>{{portal|Aviation
}}</div>{{Div col|colwidth=30em}}
* [[Circular wing]]
* [[List of Nikola Tesla patents]]
* [[List of VTOL aircraft]]
* [[McDonnell Douglas DC-X]]
* [[Tiltrotor#Mono tiltrotor|Mono tiltrotor]]
* [[Peter Bielkowicz]]
* [[Proprotor]]
* [[PTOL]]
* [[Quad (rocket)]]
* [[Reusable Vehicle Testing]] project of the Japanese Space Agency [[JAXA]]
* [[Rotor wing]]
* [[Thrust reversal]]
* [[Thrust vectoring]]
* [[Vertical Flight Society]]
* [[Tiltrotor]]
* [[VTOL X-Plane]] of [[DARPA]]
{{div col end}}

== References ==
{{reflist}}

== Bibliography ==
{{Refbegin}}
* Allen, Francis J. "Bolt upright: Convair's and Lockheed's VTOL fighters". ''Air Enthusiast'' (Key Publishing), Volume 127, January/February 2007. {{ISSN|0143-5450}}.
* {{cite book |last1=Alsalem |first1=Ahmed |title=2023 IEEE Conference on Technologies for Sustainability (SusTech) |last2=Zohdy |first2=Mohamed |date=2023 |isbn=979-8-3503-4548-3 |pages=130–137 |chapter=A Review on Civil Applications of Vertical Take-Off and Landing Vehicles |doi=10.1109/SusTech57309.2023.10129574}}
* Boniface, Patrick. "Tilt-wing Testing". ''Aeroplane,'' Vol. 28, no. 3, March 2000, pp.&nbsp;72–78.
* Campbell, John P. ''Vertical Takeoff & Landing Aircraft.'' New York: The MacMillan Company, 1962.
* Harding, Stephen. "Flying Jeeps: The US Army's Search for the Ultimate 'Vehicle{{'"}}. ''Air Enthusiast'', No. 73, January/February 1998, pp.&nbsp;10–12. Stamford, Lincs, UK: Key Publishing. {{ISSN|0143-5450}}.
* Jackson, Paul A. ''German Military Aviation 1956–1976''. Hinckley, Leicestershire, UK: Midland Counties Publications, 1976. {{ISBN|0-904597-03-2}}.
* Khurana, K. C. ''Aviation Management: Global Perspectives''. Singapore: Global India Publications, 2009. {{ISBN|978-9-3802-2839-6}}.
* Markman, Steve and Bill Holder. ''Straight Up: A History of Vertical Flight''. Atglen, Pennsylvania: Schiffer Publishing, 2000. {{ISBN|0-7643-1204-9}}.
* Norton, Bill. ''Bell Boeing V-22 Osprey, Tiltrotor Tactical Transport''. Earl Shilton, Leicester, UK: Midland Publishing, 2004. {{ISBN|1-85780-165-2}}.
* Rogers, Mike. ''VTOL: Military Research Aircraft''. New York: Orion Books, 1989. {{ISBN|0-517-57684-8}}.
* Büchi, Roland. ''Fascination Quadrocopter''. Norderstedt, BoD, English Version, 2011. {{ISBN|978-3-8423-6731-9}}
{{Refend}}

== External links ==
{{commonscat|V/STOL aircraft}}{{Wiktionary|VTOL}}
* [https://vertipedia.vtol.org/vstol/wheel.htm V/STOL Wheel of Misfortune] {{Webarchive|url=https://web.archive.org/web/20161104152707/http://vertipedia.vtol.org/vstol/wheel.htm |date=2016-11-04 }} 

* [http://www.vstol.org/wheel/wheel.htm V/STOL Wheel of Misfortune] {{Webarchive|url=https://web.archive.org/web/20080915174506/http://www.vstol.org/wheel/wheel.htm|date=2008-09-15}} – [http://www.pra.org/publicdl/Articles%20General/germanvstolrotorcraft.pdf Timeline of V/STOL aircraft] {{Webarchive|url=https://web.archive.org/web/20140714221402/http://www.pra.org/publicdl/Articles%20General/germanvstolrotorcraft.pdf|date=2014-07-14}}, page 5
{{Types of take-off and landing}}

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[[Category:Types of take-off and landing]]