Editing VTOL (section)

===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.

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.

====Conventional design====
[[File:Rolls-Royce Thrust Measuring Rig science museum.jpg|thumb|left|"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|left|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|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]]|date=16 July 2008}}</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|access-date=2021-04-29|website=www.nasa.gov|language=en|archive-date=2018-12-23|archive-url=https://web.archive.org/web/20181223163609/https://www.nasa.gov/centers/dryden/about/Organizations/Technology/Facts/TF-2004-08-DFRC.html|url-status=dead}}</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 |title=Pegasus: The Heart of the Harrier |date=2009 |publisher=Pen & Sword Aviation |location=Barnsley, South Yorkshire, UK |isbn=978-1-84884-042-3 |pages=29–46 |url=https://books.google.com/books?id=qTLAAwAAQBAJ |access-date=13 June 2020}}</ref> It led to the [[Bristol Siddeley Pegasus]] engine which used four rotating [[nozzle]]s to direct thrust over a range of angles.<ref>{{cite book|chapter-url=http://www.engineering108.com/Data/Engineering/aeronautical_engineering/Basics-of-Aeronautics.pdf |chapter=Airfoil |title=Basics of Aeronautics|access-date=24 May 2015}}</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|thumb|right|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 VTOL 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 |title=The genius of the naval jump-jet |url=https://www.maritimefoundation.uk/publications/maritime-2019/the-genius-of-the-naval-jump-jet/ |publisher=The Maritime Foundation |access-date=20 January 2020 |date=31 October 2019}}</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  |magazine=[[Popular Science]] |title=Tilt-engine V/STOL - speeds like a plane, lands like a copter |url=https://books.google.com/books?id=z7nkfLrLoMsC |date=March 1981 |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  |magazine=Popular Science |date=April 2006 |url=https://books.google.com/books?id=MY3SEwT-K0oC |title=V/STOL |page=118}}</ref>

Retired from the British [[Royal Navy]] in 2006,<ref>{{cite web |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 |website=FlightGlobal |access-date=20 January 2020 |date=28 March 2006}}</ref> the [[Indian Navy]] continued to operate [[Sea Harrier]]s until 2016,<ref>{{cite web |last1=Raghuvanshi |first1=Vivek |title=Indian Navy Retires Sea Harriers |url=https://www.defensenews.com/naval/2016/03/21/indian-navy-retires-sea-harriers/ |website=Defense News |access-date=20 January 2020 |date=21 March 2016}}</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 |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 |website=National Interest |access-date=20 January 2020 |date=13 October 2018}}</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 |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 |date=2012-07-09 |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 |url=http://www.spacex.com/press.php?page=20130310 |title=Grasshopper Completes Highest Leap to Date |date=10 March 2013 |publisher=SpaceX.com |access-date=11 March 2013 |archive-date=29 April 2013 |archive-url=https://web.archive.org/web/20130429060358/http://www.spacex.com/press.php?page=20130310 |url-status=dead }}</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 |url=https://www.facebook.com/SpaceX/posts/10153372146765131 |title= Grasshopper flies to its highest height to date |publisher=SpaceX |work=Social media information release |date=12 October 2013 |access-date=14 October 2013 |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|language=en|access-date=2021-04-29}}</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|url=https://www.blueorigin.com/news/news/blue-origin-makes-historic-rocket-landing |title=Blue Origin make historic rocket landing |work=Blue Origin |date= November 24, 2015|accessdate= November 24, 2015}}</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.<ref>{{Cite web|date=2013-08-20|title=SpaceX reusable rocket will cut space launch prices 100 fold|last=Puiu|first=Tibi|url=https://www.zmescience.com/space/spacex-reusable-rocket-100-times-cheaper-0432423/|access-date=2021-04-29|website=ZME Science|language=en-US}}</ref>