Editing VTOL (section)

===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|title=Nikola Tesla's Curious Contrivance|last=Rayl|first=A. J. S.|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|url=https://www.globalsecurity.org/military/systems/aircraft/tiltrotor.htm|title=Tiltrotor|website=www.globalsecurity.org|access-date=2019-10-20}}</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|upright|[[Convair XFY-1 Pogo]] in 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 |magazine=Life|url={{google books |plainurl=y |id=JD8EAAAAMBAJ|page=142}}|title=The new Vertijet's straight-up flight: X-13 takes off like a rocket, lands tailfirst|date=1957-05-20|publisher=Time Inc|language=en|page=136}}</ref>

The use of vertical fans driven by engines was investigated in the 1950s. The US built an aircraft where the [[Ryan XV-5 Vertifan|jet exhaust drove the fans]], while British projects not built included fans driven by mechanical drives from the jet engines.{{citation needed|date=November 2011}}

[[File:Xv-15 inflight.jpg|thumb|left|[[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|title=Another one for the X files: The Boeing Canard Rotor/Wing demonstrator officially becomes X-50A|last=Simonsen|first=Erik|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]]s to power the rotor on take-off and landing but which then used two [[Napier Eland]] [[turboprop]]s 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|left|[[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|url=https://books.google.com/books?id=ESWo4Zl5g1IC&pg=PA134|title=Aviation Management: Global Perspectives|last=Khurana|first=K. C.|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>{{Unreliable source?|reason=domain on WP:BLACKLIST|date=June 2016}}<ref name=baesystems>{{Cite web|url=https://www.baesystems.com/en/home|access-date=2021-04-29|website=BAE Systems {{!}} International|language=en|title=Forgotten 1960s 'Thunderbirds' projects brought to life}}</ref>

In 2018, Opener Aero demonstrated an electrically powered fixed-wing VTOL aircraft, the [[Opener BlackFly|Blackfly]], which the manufacturer claims is the world's first ultralight fixed-wing, all-electric, VTOL aircraft.<ref name="Oconnor12Jul18">{{cite web|url = https://www.avweb.com/avwebflash/news/Opener-Reveals-Ultralight-eVTOL-231121-1.html|title = Opener Reveals Ultralight eVTOL|access-date = 13 July 2018|last = O'Connor|first = Kate|work = AVweb|date = 12 July 2018|archive-date = 27 January 2023|archive-url = https://web.archive.org/web/20230127092714/https://www.avweb.com/avwebflash/news/Opener-Reveals-Ultralight-eVTOL-231121-1.html|url-status = dead}}</ref>

====Modern drones====
[[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>