Editing Bell UH-1 Iroquois (section)

===Twin-engine variants===
{| class="wikitable plainrowheaders" style="float: right; margin-right: 0; margin-left: 1em; text-align: right;"
|-
! scope="col" | Model
! scope="col" | Engines
! scope="col" | Rotors
! scope="col" | [[First flight|F.F.]] Year
|-
! scope="row" | UH-1/CH-118/204/5
| 1
| 2
| 1956
|-
! scope="row" | UH-1N/CH-135/212
| 2
| 2
| 1968
|-
! scope="row" | 412/CH-146/UH-2
| 2
| 4
| 1979
|-
! scope="row" | UH-1Y
| 2
| 4
| 2001
|}
The single-engine UH-1 variants were followed by the twin-engine [[UH-1N Twin Huey]] ([[Bell 212]]) and years later the [[UH-1Y Venom]].<ref name= "remarkheuy 2016"/> Bell began development of the UH-1N for Canada in 1968. It changed to the more powerful [[Pratt & Whitney Canada PT6T]] twin-engine set. The US also ordered the helicopter with the USAF receiving it in 1970. Canada's military, the U.S. Marine Corps, and the U.S. Navy first received the model in 1971.<ref name="Donald p113">Donald 1997. p. 113.</ref><ref name= "remarkheuy 2016"/>

In 1996, the USMC launched the [[H-1 upgrade program]] via the award of a contract to Bell Helicopter for development of the improved UH-1Y and [[AH-1Z Viper|AH-1Zs]] variants.<ref name="mod_battle">Donald, David. ''Modern Battlefield Warplanes''. London: AIRTime Publishing, 2004. {{ISBN|1-880588-76-5}}.</ref><ref>{{cite web |url= https://www.flightglobal.com/helicopters/retrospective-how-the-uh-1-huey-changed-modern-warfare/130259.article |title= RETROSPECTIVE: How the UH-1 'Huey' changed modern warfare |publisher= Flight International |first= Garrett |last= Reim |date= 12 December 2018}}</ref> The UH-1Y includes a lengthened cabin, four-blade rotor, and two more powerful [[General Electric T700|GE T700]] engines.<ref name="UH-1Y_guide">{{cite web |url= http://www.bellhelicopter.com/en/aircraft/military/pdf/UH1Y_PG_3-06_web.pdf |title= Bell UH-1Y pocket guide |publisher= Bell Helicopter |date= March 2006 |access-date= 20 January 2010 |archive-date= 29 December 2010 |archive-url= https://web.archive.org/web/20101229201940/http://www.bellhelicopter.com/en/aircraft/military/pdf/UH1Y_PG_3-06_web.pdf |url-status= dead }}</ref> The UH-1Y entered service with the USMC in 2008.<ref>{{cite web |last= Trimble |first= Stephen |url= http://www.flightglobal.com/articles/2008/08/18/314915/uh-1y-declared-operational-after-12-year-development.html |title= UH-1Y declared operational after 12-year development phase |publisher= Flightglobal.com |date= 18 August 2008 |access-date= 24 January 2010 |archive-date= 2 September 2008 |archive-url= https://web.archive.org/web/20080902004704/http://www.flightglobal.com/articles/2008/08/18/314915/uh-1y-declared-operational-after-12-year-development.html |url-status= dead }}</ref>

The [[Bell 412]] is an improved 4-rotor version of the twin-engined Bell 212, and while not adopted by the US, was chosen by Canada ([[Bell CH-146 Griffon|CH-146 Griffon]]), license produced in Italy as the Augusta-Bell AB412, and is going to be made for the Japan Self Defense Force in Japan by Subaru.<ref name=":1">{{Cite web |title=Bell / Agusta Bell 412 - Aerospace Technology |url=https://www.aerospace-technology.com/projects/bell-412/ |access-date=2024-04-26 |website=www.aerospace-technology.com}}</ref> It is a popular commercial and military helicopter, and it competed in the early 2000s Army Light Utility Helicopter program, but lost to what would be the [[Eurocopter UH-72 Lakota|UH-72 Lakota.]]<ref>{{Cite web |title=Bell Helicopter LUH Submission Surpasses 3.1 Million Flight Hour Milestone |url=https://verticalmag.com/press-releases/bell-helicopter-luh-submission-surpasses-3-1-million-flight-hour-milestone-html/ |access-date=2024-04-26 |website=Vertical Mag |language=en-US}}</ref><ref name=":0">{{Cite web |title=Airbus wins US Army UH-72A Lakota upgrade contract {{!}} Shephard |url=https://www.shephardmedia.com/news/air-warfare/airbus-wins-us-army-uh-72a-lakota-upgrade-contract/ |access-date=2024-04-26 |website=www.shephardmedia.com |language=en}}</ref> That program replaced aging UH-1 and OH-58A/C models being used by the National Guard.<ref name=":0" />