Editing V-tail

{{Short description|Aircraft tail that incorporates rudder and elevators in a V shape}}
[[File:Ntps-b35-N8718A-071012-02-12.jpg|thumb|1950 V-tailed [[Beechcraft Bonanza#Model 35 Bonanza|B35]] still operated by the [[National Test Pilot School]] at the [[Mojave Air and Space Port]]]]
[[File:N178FA Cirrus Vision SF50 FDK MD1A.jpg|thumb|Rear view of the [[Cirrus Vision SF50]]'s V-tail and engine outlet]]
[[File:Fouga magister.jpg|thumb|The V-tail of a Belgian Air Force [[Fouga CM.170 Magister]]]]
[[File:UltraflightLazairSeriesIII.jpg|thumb|An [[Ultraflight Lazair]] showing its inverted V-tail covered with translucent [[polyvinyl fluoride|Tedlar]]]]
The '''V-tail''' or ''vee-tail'' (sometimes called a '''butterfly tail'''<ref>{{cite book |title=Aircraft Flight |last1=Barnard |first1=R.H. |last2=Philpott |first2=D.R. |edition=4th |year=2010 |publisher=Prentice Hall |location=Harlow, England |isbn=978-0-273-73098-9 |page=275 |chapter=10. Aircraft control}}</ref> or '''Rudlicki's V-tail'''<ref name="auto">Gudmundsson S. (2013). "General Aviation Aircraft Design: Applied Methods and Procedures" (Reprint). Butterworth-Heinemann. p. 489. {{ISBN|0123973295}}, 9780123973290</ref>{{cn|date=July 2023|reason=needs quote to show that this is not just some trivial reference to Rudlicki}}) of an aircraft is an unconventional arrangement of the tail control surfaces that replaces the traditional vertical and horizontal surfaces with two surfaces set in a V-shaped configuration. It is not widely used in aircraft design. The aft edge of each twin surface is a hinged control surface called a ruddervator, which combines the functions of both a [[Rudder#Aircraft rudders|rudder]] and [[Elevator (aeronautics)|elevator]].

==History==
The V-tail was invented in 1930 by Polish engineer [[Jerzy Rudlicki]]<ref name="auto"/> and was tested for the first time on a [[Hanriot HD.28]] trainer, modified by [[Poland|Polish]] [[aerospace manufacturer]] [[Plage i Laśkiewicz|Plage and Laśkiewicz]] in the summer of 1931.{{cn|date=July 2023|reason=specific claim}}

==Variants==
The X-shaped tail surfaces of the experimental [[Lockheed XFV]] were essentially a V tail that extended both above and below the fuselage.

=== Conventional ===
The most popular conventionally V-tailed aircraft that has been mass-produced is the [[Beechcraft Bonanza]] Model 35, often known as the ''V-tail Bonanza'' or simply ''V-Tail''. Other examples include the [[Lockheed F-117 Nighthawk]] stealth attack aircraft and the [[Fouga CM.170 Magister]] trainer. The [[Cirrus Vision SF50]] jet is a recent example of a civilian aircraft adopting the V-tail. Some gliders, like the [[Lehtovaara PIK-16 Vasama]], were designed with a V-tail, but the production Vasamas had a [[cruciform tail]].<ref name="Flightpg212">{{Cite magazine |title=Sport and Business |magazine=Flight International |date=17 August 1961 |page=212 |url=http://www.flightglobal.com/pdfarchive/view/1961/1961%20-%201110.html |access-date=13 December 2017}}</ref>

===Inverted===
The [[Blohm & Voss P 213]] ''Miniaturjäger'' was one of the first aircraft to have an inverted V-tail. [[Unmanned aerial vehicle]]s such as the [[History of unmanned aerial vehicles#Amber|LSI Amber]], [[General Atomics Gnat]] and [[General Atomics MQ-1 Predator]] would later feature this type of tail. In [[Pusher configuration|pusher]] UAVs, with propeller at the back, downward tail fins can provide yaw stability without interfering with the propeller. The [[Ultraflight Lazair]] ultralights, of which over 2,000 were produced, featured an inverted V-tail, which also carried the rear landing gear.<ref name="Hunt1">Hunt, Adam & Ruth Merkis-Hunt: ''Skeletal Remains'', pages 64-70. Kitplanes Magazine, September 2000.</ref>

==Advantages==
Ideally, with fewer surfaces than a conventional three-aerofoil tail or a [[T-tail]], the V-tail is lighter and has less [[Wetted area|wetted surface area]], so thus produces less [[lift-induced drag|induced]] and [[parasitic drag]]. However, [[National Advisory Committee for Aeronautics|NACA]] studies indicated that the V-tail surfaces must be larger than simple projection into the vertical and horizontal planes would suggest, such that total wetted area is roughly constant; reduction of intersection surfaces from three to two does, however, produce a net reduction in drag through elimination of some [[Parasitic drag#Interference drag|interference drag]].<ref name="raymer">{{cite book |title=Aircraft Design: A Conceptual Approach |first=Daniel P. |last=Raymer |edition=3rd |year=1999 |publisher=American Institute of Aeronautics and Astronautics |location=Reston, Virginia |isbn=1-56347-281-3 |page=78}}</ref>

Light jet aircraft such as the [[Cirrus Vision SF50]], the [[Eclipse 400]], the [[Sonex SubSonex]] or larger jet aircraft, such as the [[Northrop Grumman RQ-4 Global Hawk]] unmanned aerial drone often have the power plant placed outside the aircraft. In such cases V-tails are used to avoid placing the vertical stabilizer in the exhaust of the engine, which would disrupt the flow of the exhaust, reducing thrust and increasing wear on the stabilizer, possibly leading to damage over time.<ref name="Cirrus">{{cite web |url=http://www.the-jet.com/infobase.html |archive-url=https://web.archive.org/web/20061209140504/http://www.the-jet.com/infobase.html |url-status=dead |archive-date=2006-12-09 |title=Cirrus SJ50 Design Notes |access-date=2008-08-14 |work=www.the-jet.com|publisher = Cirrus Design Corporation|year = 2008}}</ref>

In military aircraft, V-tails reduce the number of right angles on an aircraft, improving its [[stealth aircraft|stealth]] characteristics.<ref>{{Cite web|url=https://www.forbes.com/sites/davidaxe/2021/07/19/look-closely-at-russias-checkmate-fighter-its-tail-is-one-key-to-its-stealth/|title=Look Closely At Russia's Checkmate Fighter—Its Tail Is One Key To Its Stealth|first=David|last=Axe|website=Forbes}}</ref>

==Disadvantages==
In the mid-1980s, the [[Federal Aviation Administration]] re-assessed the Beechcraft Bonanza due to safety concerns. While the Bonanza met the initial certification requirements, it had a history of fatal mid-air breakups during extreme stress, at a rate exceeding the accepted norm. The type was deemed airworthy and restrictions removed after Beechcraft issued a structural modification as an [[Airworthiness Directive]].<ref name="FAA">{{cite web |url=http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgAD.nsf/0/21b1b224dff2889286256d2600546895!OpenDocument&ExpandSection=1&Click= |title=FAA Airworthiness Directive 93-CE-37-AD as Amended |access-date=2008-08-14 |work=Federal Register:(Volume 68, Number 93)Docket No. 93-CE-37-AD; Amendment 39-13147; AD 94-20-04 R2 |publisher=Federal Register |date=May 14, 2003 }}</ref>

V-tailed aircraft require longer rear fuselages than aircraft with conventional empennages to prevent [[Yaw (rotation)|yaw]]ing.{{Citation needed|date=December 2017}} This tendency, called "snaking", was apparent on taking off and landing on the [[Fouga CM.170 Magister]], which has a relatively short fuselage.{{Citation needed|date=December 2017}}

==Ruddervators==
[[File:YF-23 top view.jpg|thumb|A top-down view of the [[Northrop YF-23]] ''Gray Ghost'' prototype fighter jet, showing its distinctive wide V-tail and ruddervators]]
Ruddervators are the control surfaces on an airplane with a V-tail configuration. They are located at the trailing edge of each of the two [[airfoil]]s making up the tail of the plane. The first use of ruddervators may have been on the [[Coandă-1910]]'s X-tail, although there is no proof that the aircraft ever flew.<ref name="L'Aéronautique">{{cite journal |year=1935 |journal=L'Aéronautique |volume=17 |page=333 |url=https://books.google.com/books?id=ZFfmAAAAMAAJ&q=Rudlicki++Coanda|title=L'Aéronautique, Volume 17|language=fr }}</ref> The later [[Coandă-1911]] flew with ruddervators on its X-tail.<ref name="Flight28Oct1911">{{Cite web |url=http://www.flightglobal.com/pdfarchive/view/1911/1911%20-%200942.html|title = Flight 28 October 1911 |access-date=11 January 2011 |last=Flight |author-link=Flight International |date=October 1911}}</ref> Later [[Poland|Polish]] engineer [[Jerzy Rudlicki]] designed the first practical ruddervators in 1930, tested on a modified [[Hanriot HD.28]] trainer in 1931.

The name is a [[portmanteau]] of "rudder" and "elevator." In a conventional aircraft tail configuration, the rudder provides [[Aircraft principal axes|yaw]] (horizontal) control and the elevator provides [[Aircraft principal axes|pitch]] (vertical) control.

Ruddervators provide the same control effect as conventional control surfaces, but through a more complex control system that actuates the control surfaces in unison. Yaw moving the nose to the left is produced on an upright V tail by moving the pedals left which deflects the left-hand ruddervator down and left and the right-hand ruddervator up and left. The opposite produces yaw to the right. Pitch nose up is produced by moving the control column or stick back which deflects the left-hand ruddervator up and right and the right-hand ruddervator up and left. Pitch nose down is produced by moving the control column or stick forward which induces the opposite ruddervator movements.<ref name="Eckalbar">{{cite web |url=http://www.beechcraft.org/vtail/eckalbar/rudder.html |title=Simple Aerodynamics Of The V-Tail |access-date=2008-08-13 |last=Eckalbar |first=John C. |year=1986}}</ref>

==See also==
* [[Cruciform tail]]
* [[Pelikan tail]]
* [[T-tail]]
* [[Twin tail]]

==References==
{{Reflist}}

==External links==
{{commons|V-shaped tail aircraft|examples of V-shaped tail aircraft}}
*[http://www.beechcraft.org/vtail/eckalbar/rudder.html Simple Aerodynamics Of The V-Tail, from "Flying the Beech Bonanza" by Eckalbar, John C]

{{Aircraft components}}

{{DEFAULTSORT:V-Tail}}
[[Category:Aircraft tail configurations]]
[[Category:Polish inventions]]
[[Category:V-tail aircraft| ]]