View source for Tiltrotor

{{Short description|Aircraft type}}
{{use American English|date=August 2022}}
{{use mdy dates|date=August 2022}}
[[File:US Navy 061206-N-0458E-076 A U.S. Marine Corps V-22 Osprey helicopter practices touch and go landings on the flight deck of the multipurpose amphibious assault ship USS Wasp (LHD 1).jpg|thumb|upright=1.1|The [[Bell Boeing V-22 Osprey]]]]
A '''tiltrotor''' is a [[rotorcraft]] that generates [[lift (force)|lift]] and [[thrust|propulsion]] by way of one or more powered [[Helicopter rotor|rotor]]s (sometimes called ''[[proprotor]]s'') mounted on rotating [[shaft (mechanical engineering)|shaft]]s or [[nacelle]]s usually at the ends of a fixed [[wing]]. Almost all tiltrotors use a [[transverse rotor]] design, with a few exceptions that use other [[multirotor]] layouts.
Tiltrotor design combines the [[VTOL]] capability of a [[helicopter]] with the speed and [[range (aircraft)|range]] of a conventional [[fixed-wing aircraft]].  For vertical flight, the rotors are angled so the [[plane of rotation]] is horizontal, generating lift the way a normal [[helicopter rotor]] does.  As the aircraft gains speed, the rotors are progressively tilted forward, with the plane of rotation eventually becoming vertical.  In this mode the rotors provide [[thrust]] as a [[propeller (aircraft)|propeller]], and the [[airfoil]] of the fixed wings takes over providing the lift via the forward motion of the entire aircraft.  Since the rotors can be configured to be more efficient for propulsion (e.g. with root-tip twist) and it avoids a helicopter's issues of [[retreating blade stall]], the tiltrotor can achieve higher [[cruise speed]]s and [[maximum takeoff weight|takeoff weight]]s than helicopters.
A tiltrotor aircraft differs from a [[tiltwing]] in that only the rotor pivots rather than the entire wing.  This method trades off efficiency in vertical flight for efficiency in [[STOL]]/[[STOVL]] operations.

==History==
[[File:Original Tiltrotor Patent.gif|thumb|Original Patent filed May 28, 1929]]
[[File:Trascendental_Model_1-G.jpg|thumb|[[Transcendental Model 1-G]] hovering]]
[[File:Curtiss-Wright X-19 flying.jpg|thumb|[[Curtiss-Wright X-19]] experimental VTOL plane in flight]]
[[File:XV-15 N703NA USCG.jpg|thumb|A [[Bell XV-15]] prepares to land]]

The first work in the direction of a tilt-rotor (French "Convertible") seems to have originated ca. 1902 by the French-Swiss brothers Henri and Armand Dufaux, for which they got a patent in February 1904, and made their work public in April 1905.<ref>[http://www.pionnair-ge.com/spip1/spip.php?article7 Le premier vol d’un hélicoptère à moteur à explosion, produit des frères Dufaux (1905)]</ref>{{Unreliable source?|date=February 2020}}
Concrete ideas of constructing [[VTOL|vertical take-off and landing]] (VTOL) aircraft using helicopter-like rotors were pushed further in the 1930s. The first design resembling modern tiltrotors was patented by George Lehberger in May 1930, but he did not further develop the concept. In [[World War II]], Weserflug in Germany came up with the concept of their P.1003/1 around 1938, which was tilting to the top with part of the wings but not the full wings, so it may be in between tilt-rotor and tilt-planes. Shortly after a [[Germany|German]] [[prototype]], the [[Focke-Achgelis Fa 269]], was developed starting in 1942, which was tilting to the ground, but never flew.<ref>{{cite book|last=Springmann|first=Enno |author2=Gottfried Hilscher |title=Focke: Flugzeuge und Hubschrauber von Heinrich Focke 1912-1961|publisher=Aviatic-Verlag GmbH|year=1997|isbn=3-925505-36-9}}</ref><ref>{{cite book|last=Nowarra|first=Heinz|author-link=Heinz Nowarra|title=Die Deutsche Luftrüstung 1933-1945|publisher=Bernard & Graefe|date=1985–1988|isbn=3-7637-5464-4}}</ref><ref>{{cite book |last=Maisel |first=M.D |author-link=M.D Maisel |url=https://history.nasa.gov/monograph17.pdf |title=The History of the XV-15 Tilt Rotor Research Aircraft: From Concept to Flight |publisher=National Aeronautics and Space Administration, Office of Policy and Plans, NASA History Division |date=2000}}</ref> [[Platt-LePage Aircraft Company|Platt and LePage]] patented the PL-16, the first American tiltrotor aircraft.  However, the company shut down in August 1946 due to lack of capital.<ref>{{cite web|url=http://www.helis.com/types/tiltrotor.php|title=Tiltrotors|website=helis.com|access-date=1 April 2018}}</ref>

Two prototypes which made it to flight were the one-seat [[Transcendental Model 1-G]] and two seat Transcendental Model 2, each powered by a single reciprocating engine. Development started on the Model 1-G in 1947, though it did not fly until 1954. The Model 1-G flew for about a year until a crash in [[Chesapeake Bay]] on July 20, 1955, destroying the prototype aircraft but not seriously injuring the pilot. The Model 2 was developed and flew shortly afterwards, but the [[US Air Force]] withdrew funding in favor of the Bell XV-3 and it did not fly much beyond hover tests. The Transcendental 1-G is the first tiltrotor aircraft to have flown and accomplished most of a helicopter to aircraft transition in flight (to within 10 degrees of true horizontal aircraft flight).

Built in 1953, the experimental [[Bell XV-3]] flew until 1966, proving the fundamental soundness of the tiltrotor concept and gathering data about technical improvements needed for future designs.

A related technology development is the [[tiltwing]]. Although two designs, the [[Canadair CL-84 Dynavert]] and the [[LTV XC-142]], were technical successes, neither entered production due to other issues. Tiltrotors generally have better hover efficiency than tiltwings, but less than helicopters.<ref>Warwick, Graham. [http://www.flightglobal.com/pdfarchive/view/1992/1992%20-%200262.html "Tilting at targets"] page 44 ''[[Flight International]]'', Number 4304, Volume 141, 5–11 February 1992. Accessed: 4 January 2014.</ref>

In 1968, Westland Aircraft displayed their own designs—a small experimental craft (We 01C) and a 68-seater transport We 028—at the [[Society of British Aerospace Companies|SBAC]] [[Farnborough Airshow]].<ref>[http://www.flightglobal.com/pdfarchive/view/1968/1968%20-%202034.html "twenty Sixth SBAC Show"] ''Flight International'', 19 September 1968 p446</ref> In 1972, with funding from [[NASA]] and the [[U.S. Army]], [[Bell Helicopter Textron]] started development of the [[XV-15]], a twin-engine tiltrotor research aircraft. Two aircraft were built to prove the tiltrotor design and explore the operational flight envelope for military and civil applications.<ref name="ames1">[http://www.simlabs.arc.nasa.gov/library/tiltrotor/ctr20th.html#History "History of tiltrotor technology", NASA Ames Research Center] {{webarchive|url=https://web.archive.org/web/20080705115900/http://www.simlabs.arc.nasa.gov/library/tiltrotor/ctr20th.html |date=2008-07-05 }}</ref><ref name="nasaXv15">{{cite book |url=https://history.nasa.gov/monograph17.pdf |title=The History of the XV-15 Tilt Rotor Research Aircraft |publisher=NASA |first1=Martin D. |last1=Maisel |first2=Demo J. |last2=Giulianetti |first3=Daniel C. |last3=Dugan |series=Monographs in Aerospace History No. 17 |year=2000 |isbn=0-16-050276-4 |id=NASA SP-2000-4517}}</ref>

In 1981, using experience gained from the XV-3 and XV-15, Bell and [[Boeing]] Helicopters began developing the [[V-22 Osprey]], a twin-turboshaft military tiltrotor aircraft for the [[U.S. Air Force]] and the [[U.S. Marine Corps]].<ref name="ames1"/> Bell teamed with Boeing in developing a commercial tiltrotor, but Boeing went out in 1998 and Agusta came in for the [[AgustaWestland AW609|Bell/Agusta BA609]].<ref name="nasaXv15"/><ref name=cs2tech/> This aircraft was redesignated as the [[AW609]] following the transfer of full ownership to [[AgustaWestland]] in 2011.<ref name=Wynbrandt>{{cite news |url=http://www.ainonline.com/aviation-news/hai-convention-news/2012-02-11/aw609-finally-ready-its-close |title=AW609 Finally Ready for its Close-up |work=AINonline.com |first=James |last=Wynbrandt |date=11 February 2012 |access-date=14 February 2012 |archive-date=February 14, 2012 |archive-url=https://web.archive.org/web/20120214172623/http://www.ainonline.com/aviation-news/hai-convention-news/2012-02-11/aw609-finally-ready-its-close |url-status=dead }}</ref> Bell has also developed a tiltrotor [[unmanned aerial vehicle]] (UAV), the TR918 [[Bell Eagle Eye|Eagle Eye]].

Russia has had a few tiltrotor projects, mostly unmanned such as the [[Mil Mi-30]], and has started another in 2015.<ref>{{cite web|url=http://www.flightglobal.com/news/articles/maks-russian-helicopters-launches-unmanned-tiltrotor-416138/|title=MAKS: Russian Helicopters launches unmanned tiltrotor concept|date=27 August 2015|website=flightglobal.com|access-date=1 April 2018}}</ref>

Around 2005<ref name="boeing1">[http://boeing.com/news/releases/2005/photorelease/q3/pr_050923p-1.html "Bell-Boeing's QTR selected for Heavy Lift study"] {{webarchive|url=https://web.archive.org/web/20060830203438/http://boeing.com/news/releases/2005/photorelease/q3/pr_050923p-1.html |date=2006-08-30 }}. Boeing, 22 September 2005.</ref>–2010,<ref>Brannen, Kate. [https://archive.today/20130121104039/http://www.defensenews.com/story.php?i=4710186&c=AME&s=LAN "Pentagon Sheds Some Light on JFTL Effort"]. ''Defense News'', 15 July 2010.</ref> Bell and Boeing teamed up again to perform a conceptual study of a larger [[Bell Boeing Quad TiltRotor|Quad TiltRotor]] (QTR) for the US Army's Joint Heavy Lift (JHL) program. The QTR is a larger, four rotor version of the V-22 with two [[tandem wing]]s sets of fixed wings and four tilting rotors.

In January 2013, the [[Federal Aviation Administration|FAA]] defined US tiltrotor noise rules to comply with [[International Civil Aviation Organization|ICAO]] rules. A noise certification will cost $588,000, same as for a large helicopter.<ref name=tiltnoise>{{cite web|title=Noise Certification Standards for Tiltrotors|url=https://www.federalregister.gov/articles/2013/01/08/2013-00111/noise-certification-standards-for-tiltrotors|publisher=[[Federal Aviation Administration]]|access-date=13 January 2013|date=8 January 2013}}</ref><ref>{{cite web|title=FAA Publishes Modified Noise Rules For Tiltrotors|url=http://www.aero-news.net/subscribe.cfm?do=main.textpost&id=98a33b6f-df48-4348-88bd-c66db2d8a24a|publisher=Aero-News|access-date=13 January 2013|date=11 January 2013}}</ref>

AgustaWestland says they have free-flown a manned electric tiltrotor in 2013 called [[AgustaWestland Project Zero|Project Zero]], with its rotors inside the wingspan.<ref>{{cite magazine|last=Paur|first=Jason|title=Meet Project Zero, the World's First Electric Tilt-Rotor Aircraft|url=https://www.wired.com/autopia/2013/03/agustawestland-electric-tilt-rotor/|magazine=[[Wired (website)|Wired]]|access-date=6 March 2013|date=6 March 2013}}</ref><ref>{{cite web|title=AgustaWestland Unveils Revolutionary ''Project Zero'' Tilt Rotor Technology Demonstrator|url=http://www.asdnews.com/mobile/news/47974/AgustaWestland_Unveils_Revolutionary___Project_Zero___Tilt_Rotor_Technology_Demonstrator.htm|publisher=ASDNews|access-date=6 March 2013|archive-date=5 July 2013|archive-url=https://web.archive.org/web/20130705214242/http://www.asdnews.com/mobile/news/47974/AgustaWestland_Unveils_Revolutionary___Project_Zero___Tilt_Rotor_Technology_Demonstrator.htm|url-status=dead}}</ref><ref>"[http://www.agustawestland.com/about-us/driving-innovation/advanced-concepts/project-zero Project Zero] {{Webarchive|url=https://web.archive.org/web/20151203225623/http://www.agustawestland.com/about-us/driving-innovation/advanced-concepts/project-zero |date=December 3, 2015 }}" ''[[AgustaWestland]]''</ref>

In 2013, Bell Helicopter CEO John Garrison responded to Boeing's taking a different airframe partner for the US Army's [[Future Vertical Lift|future lift requirements]] by indicating that Bell would take the lead itself in developing the [[Bell V-280 Valor]],<ref>{{cite web|url=http://www.aviationtoday.com/rw/products/airframes/Bell-to-Take-V-22-Development-Forward-Alone-Without-Boeing_78676.html|title=Bell to Take Tiltrotor Technology Forward Without Boeing - Rotor & Wing International|date=5 March 2013|website=aviationtoday.com|access-date=1 April 2018|archive-date=October 6, 2014|archive-url=https://web.archive.org/web/20141006101540/http://www.aviationtoday.com/rw/products/airframes/Bell-to-Take-V-22-Development-Forward-Alone-Without-Boeing_78676.html|url-status=dead}}</ref> with Lockheed Martin.

In 2014, the [[Clean Sky]] 2 program (by the [[European Union]] and industry) awarded AgustaWestland and its partners $328 million to develop a "next-generation civil tiltrotor"<ref>"[http://www.agustawestland.com/about-us/driving-innovation/advanced-concepts/ngctr?WT.ac=Next%20Generation%20Civil%20TiltRotor Next Generation Civil Tiltrotor] {{Webarchive|url=https://web.archive.org/web/20150922072105/http://www.agustawestland.com/about-us/driving-innovation/advanced-concepts/ngctr?WT.ac=Next%20Generation%20Civil%20TiltRotor |date=September 22, 2015 }}" ''[[AgustaWestland]]''</ref><ref name=vert2014-09>{{cite news |first=Mike |last=Hirschberg |url=http://www.agustawestland.com/documents/17633750/23356203/body_AHS_vertiflite_NextGenCTR_Vertiflite_Sep_Oct_2014.pdf |title=The shape of things to come, part 2 |work=Vertical Magazine |date=September 2014 |access-date=13 April 2015 |url-status=dead |archive-url=https://web.archive.org/web/20150414020029/http://www.agustawestland.com/documents/17633750/23356203/body_AHS_vertiflite_NextGenCTR_Vertiflite_Sep_Oct_2014.pdf |archive-date=14 April 2015 }}</ref><ref>Pierobon, Mario. "[https://archive.today/20150413222942/http://www.propilotmag.com/archives/2015/Feb%2015/A3_AW_p1.html AW aims to be civil tiltrotor leader]" [https://archive.today/20150413222943/http://www.propilotmag.com/archives/2015/Feb%2015/A3_AW_p2.html Page 2] [https://archive.today/20150413222942/http://www.propilotmag.com/archives/2015/Feb%2015/A3_AW_p3.html Page 3] ''ProPilotMag''.</ref> design for the offshore market, with [[Critical Design Review]] near the end of 2016. The goals are tilting wing sections, 11 metric tons [[Maximum takeoff weight]], seating for 19 to 22 passengers, first flight in 2021, a cruise speed of 300 knots,<ref>{{cite web|url=http://www.ainonline.com/aviation-news/business-aviation/2015-10-12/agustawestland-plans-fly-next-gen-tiltrotor-2021 |title=AgustaWestland Plans To Fly Next-gen Tiltrotor in 2021 |work=Aviation International News}}</ref> a top speed of 330 knots, a ceiling of 25,000 feet, and a range of 500 nautical miles.<ref name=cs2tech>"[http://ec.europa.eu/research/participants/data/ref/h2020/other/guide-appl/jti/h2020-guide-techprog-cleansky-ju_en.pdf 8.6 Next Generation Civil Tiltrotor (NextGenCTR) Project – WP1]" pages 254-301. Size: 747 pages, 23 MB. ''[[Clean Sky]] 2'', 27 June 2014. Accessed: 7 October 2014.</ref><ref>Huber, Mark. "[http://www.ainonline.com/aviation-news/aviation-international-news/2014-10-05/agustawestland-pushes-ahead-larger-tiltrotor AgustaWestland Pushes Ahead with Larger Tiltrotor]" ''AINonline'', 5 October 2014. Accessed: 7 October 2014. [https://web.archive.org/web/20141007180847/http://www.ainonline.com/aviation-news/aviation-international-news/2014-10-05/agustawestland-pushes-ahead-larger-tiltrotor Archived] on 7 October 2014</ref><ref>"[http://www.cleansky.eu/sites/default/files/documents/events/20141609/6b-_frc_tiltrotor.pdf AgustaWestland civil tiltrotor]" ''AgustaWestland''</ref>

==Technical considerations==
===Controls===
In vertical flight, the tiltrotor uses controls very similar to a [[Transverse-rotor aircraft|transverse]] or [[tandem-rotor]] helicopter. [[Yaw (flight)|Yaw]] is controlled by tilting its rotors in opposite directions. [[Roll (flight)|Roll]] is provided through differential power or thrust.  [[Pitch (flight)|Pitch]] is provided through rotor blades [[Helicopter flight controls|cyclic]]-, or [[nacelle]], tilt.  Vertical motion is controlled with conventional rotor [[blade pitch]] and either a conventional helicopter collective control lever (as in the [[Bell/Agusta BA609]]) or a unique control similar to a fixed-wing engine control called a thrust control lever (TCL) (as in the Bell-Boeing [[V-22 Osprey]]).<ref name="Norton V-22">Norton, Bill. ''Bell Boeing V-22 Osprey, Tiltrotor Tactical Transport''. Midland Publishing, 2004. {{ISBN|1-85780-165-2}}.</ref>

===Speed and payload issues===
[[File:VTOL DiscLoad-LiftEfficiency.svg|thumb|right|VTOL disc loading lift efficiency]]

The tiltrotor's advantage is significantly greater speed than a helicopter. In a helicopter the maximum forward speed is defined by the turn speed of the [[helicopter rotor|rotor]]; at some point the helicopter will be moving forward at the same speed as the spinning of the backwards-moving side of the rotor, so that side of the rotor sees zero or negative [[airspeed]], and begins to [[stall (flight)|stall]]. This limits modern helicopters to cruise speeds of about 150 [[knot (unit)|knot]]s / 277&nbsp;km/h. However, with the tiltrotor this problem is avoided, because the proprotors are perpendicular to the motion in the high-speed portions of the flight regime (and thus not subject to this reverse flow condition), so the tiltrotor has relatively high maximum speed—over 300&nbsp;knots / 560&nbsp;km/h has been demonstrated in the two types of tiltrotors flown so far, and cruise speeds of 250&nbsp;knots / 460&nbsp;km/h are achieved.<ref name="Norton V-22" />

This speed is achieved somewhat at the expense of [[Payload (air and space craft)|payload]]. As a result of this reduced payload, some{{Who|date=October 2014}} estimate that a tiltrotor does not exceed the transport efficiency (speed times payload) of a helicopter,<ref>{{cite book|url=http://www.nap.edu/books/0309064295/html/82.html#p0200064b99960082001|title=Front Matter - Naval Expeditionary Logistics: Enabling Operational Maneuver from the Sea - The National Academies Press|website=nap.edu|year=1999 |access-date=1 April 2018|doi=10.17226/6410|hdl=10945/62493 |isbn=978-0-309-06429-3 }}</ref> while others conclude the opposite.<ref name=cs2tech/> Additionally, the tiltrotor propulsion system is more complex than a conventional helicopter due to the large, articulated nacelles and the added wing; however, the improved cruise efficiency and speed improvement over helicopters is significant in certain uses.  Speed and, more importantly, the benefit to overall response time is the principal virtue sought by the military forces that are using the tiltrotor. Tiltrotors are inherently less noisy in forward flight (airplane mode) than helicopters.{{citation needed|date=May 2009}} This, combined with their increased speed, is expected to improve their utility in populated areas for commercial uses and reduce the threat of detection for military uses. Tiltrotors, however, are typically as loud as equally sized helicopters in hovering flight. Noise simulations for a 90-passenger tiltrotor indicate lower cruise noise inside the cabin than a [[Bombardier Dash 8]] airplane, although low-frequency vibrations may be higher.<ref>Grosveld, Ferdinand W. et al. "[https://ntrs.nasa.gov/search.jsp?R=20130013992 Interior Noise Predictions in the Preliminary Design of the Large Civil Tiltrotor (LCTR2)]" 20130013992 ''[[NASA]]'', 21 May 2013. Accessed: 9 June 2014.</ref>

Tiltrotors also provide substantially greater cruise altitude capability than helicopters. Tiltrotors can easily reach 6,000&nbsp;m / 20,000&nbsp;ft or more whereas helicopters typically do not exceed 3,000&nbsp;m / 10,000&nbsp;ft altitude.  This feature will mean that some uses that have been commonly considered only for fixed-wing aircraft can now be supported with tiltrotors without need of a runway. A drawback however is that a tiltrotor suffers considerably reduced payload when taking off from high altitude.

==Mono tiltrotor==
{{Redirect|Mono tiltrotor|the research project|Baldwin Mono Tiltrotor|section=yes}}
A mono tiltrotor aircraft uses a tiltable rotating [[Propeller (aircraft)|propeller]], or ''[[Coaxial rotors|coaxial proprotor]]'', for [[lift (force)|lift]] and [[thrust|propulsion]]. For vertical flight the proprotor is angled to direct its thrust downwards, providing lift. In this mode of operation the craft is essentially identical to a helicopter. As the craft gains speed, the coaxial proprotor is slowly tilted forward, with the blades eventually becoming [[perpendicular]] to the ground. In this mode the wing provides the lift, and the wing's greater efficiency helps the tiltrotor achieve its high speed. In this mode, the craft is essentially a turboprop aircraft. A mono tiltrotor aircraft is different from a conventional tiltrotor in which the proprotors are mounted to the [[wing tip]]s, in that the ''coaxial proprotor'' is mounted to the aircraft's [[fuselage]].  As a result of this structural efficiency, a mono tiltrotor exceeds the transport efficiency (speed times payload) of both a helicopter and a conventional tiltrotor.  [[Baldwin Mono Tiltrotor|One design study]] concluded that if the mono tiltrotor could be technically realized, it would be half the size, one-third the weight, and nearly twice as fast as a helicopter.<ref name=ONR1>[https://web.archive.org/web/20141220233611/http://handle.dtic.mil/100.2/ADA428702 Article title] Leishman, J. G., Preator, R., Baldwin, G. D., Conceptual Design Studies of a Mono Tiltrotor (MTR) Architecture, U.S. Navy Contract Number: N00014-03-C-0531, 2004.</ref>

In vertical flight, the mono tiltrotor uses controls very similar to a coaxial helicopter, such as the [[Kamov Ka-50]]. [[Yaw (flight)|Yaw]] is controlled for instance by increasing the lift on the upper proprotor while decreasing the lift on the lower proprotor.  [[Roll (flight)|Roll]] and [[Pitch (flight)|pitch]] are provided through rotor cyclic. Vertical motion is controlled with conventional rotor blade [[blade pitch]].<ref name=MTR_AHS_Jan07>{{cite web |url=http://www.baldwintechnology.com/MTR_AHS_Jan07.pdf |title=Archived copy |access-date=2009-06-05 |url-status=dead |archive-url=https://web.archive.org/web/20081007162342/http://www.baldwintechnology.com/MTR_AHS_Jan07.pdf |archive-date=2008-10-07 }} Baldwin, G. D., 'Preliminary Design Studies of a Mono Tiltrotor (MTR) with Demonstrations of Aerodynamic Wing Deployment', AHS International Specialists Meeting, Chandler, Arizona, January 23–25, 2007.</ref>

==List of tiltrotor aircraft==
{{main|List of tiltrotor aircraft}}
[[File:X-22a onground bw.jpg|thumb|[[Bell X-22]]]]<!--expand until separate TiltFan article-->

* [[AgustaWestland AW609]]
* [[AgustaWestland Project Zero]]
* [[American Dynamics AD-150]]
* [[Bell XV-3]]
* [[Bell XV-15]]
* [[Bell Eagle Eye]]
* [[Bell MV-75]]
* [[Bell Boeing V-22 Osprey]]
* [[Curtiss-Wright X-19]]
* [[Focke-Achgelis Fa 269]]
* [[IAI Panther]]
* [[Transcendental Model 1-G]]

<gallery mode="nolines" widths="250" heights="250">
File:BA609 02.jpg|A [[AgustaWestland AW609|BA609]] (now AW609) in airplane mode at [[Paris Air Show]] 2007
File:Bell V-280 Valor high speed cruise demo, 2019 Alliance Air Show.jpg|[[Bell MV-75]]
</gallery>

==See also==
* [[Pitch drop-back]]
* [[Tiltjet]]
* [[Tailsitter]]
* [[PTOL]]
* [[Thrust vectoring]]

==References==
{{Reflist}}

==External links==
{{Commons category|Tiltrotor aircraft}}
* {{cite web |url= http://artamonoff.info/tiltrotor-hybrid-trh-14 |title= Unmanned TiltRotor Hybrid TRH-14 |publisher= Artamonoff technologies}}{{Promotion inline|date=April 2018}}
* {{cite news |url= http://www.pionnair-ge.com/spip1/article.php3?id_article=162 |title= L'invention du premier Tiltrotor de l'histoire par les frères Henri et Armand Dufaux (1907-09) |author= Jean-Claude Cailliez |date= 1 June 2006 |work= Les pionniers de l’aéronautique à Genève |language= fr}}
* Archived at [https://ghostarchive.org/varchive/youtube/20211211/Ud66wf47DX0 Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20121230024048/http://www.youtube.com/watch?v=Ud66wf47DX0&gl=US&hl=en Wayback Machine]{{cbignore}}: {{ cite video |url= https://www.youtube.com/watch?v=Ud66wf47DX0&list=PLgA_7RbhBCLDy3SXfdRCyRNKhUXKlrBJD |title= Tilt Rotor History |author= AeroSpaceNews |publisher= YouTube |date= Dec 25, 2012}}{{cbignore}}
* {{cite news |url= https://www.ainonline.com/aviation-news/business-aviation/2018-04-06/long-road-tiltrotor |title= The Long Road to the Tiltrotor |author=  Richard Ward |date= April 6, 2018 |work= AIN}}

{{Aircraft types (by method of thrust and lift)}}

[[Category:Tiltrotor aircraft| ]]
[[Category:Aircraft configurations]]