Editing Lun-class ekranoplan (section)

{{short description|Soviet ground effect vehicle}}
{{Use dmy dates|date=January 2022}}
{{Use British English |date=January 2022}}
{|{{Infobox ship begin}}
{{Infobox ship image
|Ship image=Lun-class ekranoplan 2021-09-24-3.jpg
|Ship caption=''Lun''-class ekranoplan in 2021
}}
{{Infobox ship class overview
|Name=''Lun''
|Builders=
|Operators=*{{navy|Soviet Union}}
* {{navy|Russia}}
|Class before=
|Class after=
|Subclasses=
|Cost=
|Built range=
|In service range=1987–late 1990s
|In commission range=
|Total ships building=
|Total ships planned=2
|Total ships completed=1
|Total ships cancelled=1
|Total ships active=
|Total ships laid up=
|Total ships lost=
|Total ships retired=1
|Total ships preserved=1
}}
{{Infobox ship characteristics
|Hide header=
|Header caption=
|Ship type=Attack/transport [[ground effect vehicle]]
|Ship tonnage=
|Ship displacement=Displacement n/a, weight 286 tonnes unloaded
|Ship length={{cvt|73.8|m|ftin}}
|Ship beam=(Wingspan) {{cvt|44|m|ftin}}
|Ship height={{cvt|19.2|m|ftin}}
|Ship draught=({{cvt|2.5|m|ftin}}
|Ship draft=
|Ship depth=
|Ship power=
|Ship propulsion=8 × [[Kuznetsov NK-87]] [[turbojet]] engines, {{convert|127.4|kN|lbf|abbr=on|lk=in}} thrust
|Ship sail plan=
|Ship speed={{convert|297|kn|lk=in}}
|Ship range={{cvt|1000|nmi|lk=in}}
|Ship endurance=
|Ship boats=
|Ship capacity= 100 [[tonne]]s (220,000 pounds)
|Ship troops=
|Ship complement=six officers and nine enlisted men
|Ship sensors=[[Puluchas search radar]]
|Ship EW=
|Ship armament=*6 × fixed-elevation [[P-270 Moskit]] [[anti-ship missile]] launchers
* 2 × twin 23 mm PI-23 turrets
|Ship armour=
|Ship armor=
|Ship notes=
}}
|}
{{Maplink|frame=yes||id=Q1411851|type=point|zoom=11|frame-width=310|text=Interactive map showing the position of the ''Lun''-class ekranoplan when it beached in July 2020}}

The '''''Lun''-class ekranoplan''' ([[List of ships of Russia by project number|Soviet classification]]: '''Project 903''')<ref>{{Cite web |title=Small Missile Ship-Ekranoplan - Project 903 |url=http://russianships.info/eng/warships/project_903.htm |access-date=24 November 2023 |website=russianships.info |archive-date=2 October 2024 |archive-url=https://web.archive.org/web/20241002231956/http://russianships.info/eng/warships/project_903.htm |url-status=live }}</ref> is the only [[ground effect vehicle]] (GEV) to ever be [[Initial operating capability|operationally deployed]] as a [[Surface combatant|warship]], deploying in the [[Caspian Flotilla]]. It was designed by [[Rostislav Alexeyev]] in 1975 and used by the [[Soviet Navy|Soviet]] and later [[Russian Navy|Russian]] navies from 1987 until sometime in the late 1990s.<ref name="ValueWalk">{{cite web |url=http://www.valuewalk.com/2015/09/russia-revives-ekranoplan-project/ |archive-url=https://archive.today/20151115225548/http://www.valuewalk.com/2015/09/russia-revives-ekranoplan-project/ |url-status=dead |archive-date=15 November 2015 |title=Russia Revives Its Soviet-Era Ekranoplan Project |last1=Shukla |first1=Vikas |date=9 September 2015 |website=ValueWalk |access-date=10 September 2015 }}</ref><ref name="Business Insider">{{cite web |url=http://www.businessinsider.com/the-soviet-unions-lun-class-ekanoplane-is-the-biggest-ground-effect-vehicle-ever-2014-7 |title=Here's The Astonishing Hovercraft That The Soviets Could Have Used To Invade Western Europe In The 80s |last1=Johnson |first1=Robert |last2=Rosen |first2=Armin |website=Business Insider |access-date=10 September 2015 |archive-date=21 September 2015 |archive-url=https://web.archive.org/web/20150921082937/http://www.businessinsider.com/the-soviet-unions-lun-class-ekanoplane-is-the-biggest-ground-effect-vehicle-ever-2014-7 |url-status=live }}</ref>

It flew using lift generated by the [[Ground effect (aircraft)|ground effect]] acting on its large wings when within about {{convert|4|m|ft|spell=in}} above the surface of the water. Although they might look similar to traditional aircraft, [[ekranoplans]] like the ''Lun'' are not classified as aircraft, [[seaplane]]s, [[hovercraft]], or [[hydrofoils]]. Rather, craft like the ''Lun''-class ekranoplan are classified as maritime ships by the [[International Maritime Organization]] due to their use of the ground effect, in which the craft glides just above the surface of the water.<ref name="YunBliault2009">{{cite book |author1=Liang Yun |author2=Alan Bliault |author3=Johnny Doo |title=WIG Craft and Ekranoplan: Ground Effect Craft Technology |url=https://books.google.com/books?id=oAXEphDmmEMC&pg=PA436 |date=3 December 2009 |publisher=Springer Science & Business Media |isbn=978-1-4419-0042-5 |pages=436– }}</ref>

The [[Ground effect (aerodynamics)|ground effect]] occurs when flying at an altitude of only a few metres above the ocean or ground; drag is greatly reduced by the proximity of the ground preventing the formation of wingtip vortices, thus increasing the efficiency of the wing. This effect does not occur at high altitude.<ref>{{Cite journal |last1=Cui |first1=E. |last2=Zhang |first2=X. |date=2010 |title=Chapter 18 Ground Effect Aerodynamics |s2cid=29236092 |language=en }}</ref><ref>{{Cite web |date=4 April 2017 |title=Here's a Closer Look at the Soviet Navy's 1987 Lun-Class Ekranoplan |url=https://interestingengineering.com/a-closer-look-at-the-soviet-navys-1987-lun-class-ekranoplan |access-date=31 July 2021 |website=interestingengineering.com |language=en-US |archive-date=2 October 2024 |archive-url=https://web.archive.org/web/20241002232101/https://pandg.tapad.com/tag?us_privacy=1YNY&referrer_url=&page_url=https%3A%2F%2Finterestingengineering.com%2Finnovation%2Fa-closer-look-at-the-soviet-navys-1987-lun-class-ekranoplan&owner=P%26G&bp_id=cafemedia&ch=%7B%22architecture%22%3A%22x86%22%2C%22bitness%22%3A%2264%22%2C%22brands%22%3A%5B%7B%22brand%22%3A%22%20Not%3BA%20Brand%22%2C%22version%22%3A%2299%22%7D%2C%7B%22brand%22%3A%22Google%20Chrome%22%2C%22version%22%3A%2297%22%7D%2C%7B%22brand%22%3A%22Chromium%22%2C%22version%22%3A%2297%22%7D%5D%2C%22mobile%22%3Afalse%2C%22model%22%3A%22%22%2C%22platformVersion%22%3A%225.15.0%22%7D&initiator=js |url-status=live }}</ref>

The name ''Lun'' comes from the Russian word for the [[harrier (bird)|harrier]].<ref name="Flying Magazine">{{cite journal |title=Neither Fish Nor Fowl |journal=Flying |url={{google books |id=DNnRQhLxu7YC |page=72 |plain-url=yes}} |date=July 1994 |page=72 |issn=0015-4806 }}</ref>