Editing Robinson R44 (section)

==Development==
[[File:R44 tail rotor.jpg|thumb|Closeup of the R44 tailrotor]]
Designed during the 1980s by [[Frank D. Robinson|Frank Robinson]] and his staff of engineers, the R44 first flew on 31 March 1990. The R44 '''Astro''' was awarded an [[Federal Aviation Administration|FAA]] [[Type certificate|Type Certificate]] in December [[1992 in aviation|1992]], with the first deliveries taking place in January 1993. The first R44 '''Newscopter''' featuring onboard electronic news gathering equipment was delivered in 1998.<ref name="time">{{cite web|title=Timeline: February 1998|date=15 February 1988|url=https://robinsonheli.com/timeline-milestone/february-1998/|publisher=[[Robinson Helicopter Company]]|access-date=14 February 2017|archive-date=14 February 2017|archive-url=https://web.archive.org/web/20170214180142/https://robinsonheli.com/timeline-milestone/february-1998/|url-status=dead}}</ref> In January 2000, Robinson introduced the '''Raven''' with hydraulically assisted controls<ref name="Phil">{{cite web|last1=Greenspun|first1=Philip|author-link1=Philip Greenspun|title=Robinson R44 Raven I|url=http://philip.greenspun.com/flying/robinson-r44|access-date=20 September 2014|date=July 2014}}</ref> and adjustable pedals. In July 2002, Robinson introduced the '''Raven II''' featuring a more powerful, [[fuel injection|fuel-injected]] engine and wider blades, allowing a higher gross weight and improved altitude performance.

During November 2015 Robinson announced the '''Cadet,''' a Raven I with a cargo area instead of the two back seats, a slightly less powerful engine and a more efficient muffler.<ref name="Robinson17Nov2015">{{cite press release|author=<!--Staff writer(s); no by-line.-->|title=Robinson Introduces the Two-Place R44 Cadet|url=https://robinsonheli.com/news/robinson-introduces-the-two-place-r44-cadet/|location=Torrance, CA|publisher=[[Robinson Helicopter Company]]|date=17 November 2015|access-date=19 November 2015|archive-date=30 October 2018|archive-url=https://web.archive.org/web/20181030172037/https://robinsonheli.com/news/robinson-introduces-the-two-place-r44-cadet/|url-status=dead}}</ref>

Robinson has carried out ground run testing with an [[aircraft diesel engine]] that could replace its [[Lycoming IO-540]] avgas engine. The diesel could provide better altitude performance, a fuel burn reduced from {{cvt|16 to 12|USgal|L}} per hour and better fuel availability with no lead pollution.<ref>{{cite news |url= https://www.flightglobal.com/news/articles/hai-robinson-helicopter-upbeat-on-diesel-rd-with-r-456370/ |title= Robinson Helicopter upbeat on diesel R&D with R44 Raven II |date= 6 March 2019 |author= Garrett Reim |work= Flightglobal}}</ref>

In 2023, the R550X, an unmanned helicopter drone based on the R44 Raven II, was developed.<ref>{{Cite web |last=Iosub |first=Ancuta |date=2023-12-11 |title=Rotor Technologies Begins Production of Uncrewed Helicopter Designed for Civilian Use |url=https://www.autoevolution.com/news/rotor-technologies-begins-production-of-uncrewed-helicopter-designed-for-civilian-use-225897.html |access-date=2024-11-29 |website=autoevolution |language=en}}</ref>