View source for Viking SF-2A Cygnet

{{Short description|American homebuilt aircraft design}}
{{Use dmy dates|date=January 2021}}
{{Use American English|date=January 2021}}
<!-- This article is a part of [[Wikipedia:WikiProject Aircraft]]. Please see [[Wikipedia:WikiProject Aircraft/page content]] for recommended layout. -->
{|{{Infobox aircraft begin
| name=SF-2A Cygnet
| image=File:Sisler SF-2A Cygnet G-BYYC (43960248025).jpg
| caption=
}}{{Infobox aircraft type
| type=[[Amateur-built aircraft]]
| national origin=[[United States]]
| manufacturer=[[Viking Aircraft LLC]]
| designer=Bert Sisler
| first flight=1973
| introduced= 1973
| retired=
| status=Plans available (2003)
| primary user=
| more users= <!--Limited to three in total; separate using <br /> -->
| produced= <!--years in production-->
| number built=100 (2003)
| developed from= [[Sisler SF-2 Whistler]]
| variants with their own articles=
}}
|}
The '''Viking SF-2A Cygnet''', also called the '''Sisler SF-2A Cygnet''' and the '''HAPI SF-2A Cygnet''', is an American [[STOL]] [[amateur-built aircraft]], designed by Bert Sisler and produced by [[Viking Aircraft LLC]]. The aircraft is supplied in the form of plans for amateur construction. The Cygnet first flew in 1973.<ref name="Aerocrafter">Purdy, Don: ''AeroCrafter - Homebuilt Aircraft Sourcebook'', page 285. BAI Communications, 15 July 1998. {{ISBN|0-9636409-4-1}}</ref><ref name="KitplanesJan2003">Downey, Julia: ''2003 Plans Aircraft Directory'', Kitplanes, Volume 20, Number 1, January 2003, page 29. Primedia Publications. {{ISSN|0891-1851}}</ref>
The Cygnet plans were originally marketed by the designer through his company Sisler Aircraft of [[Bloomington, Minnesota]] and later by [[HAPI Engines]], a supplier of [[Volkswagen air-cooled engine]]s. By the 1990s [[Viking Aircraft LLC|Viking Aircraft]] of [[Elkhorn, Wisconsin]] took over supplying the aircraft plans.<ref name="Aerocrafter" /><ref name="KitplanesJan2003" /><ref name="AF">{{cite web|url = http://aerofiles.com/_sa.html|title = Aircraft from Saalfield SEE Skyskootor|access-date = 4 December 2012|last = Aerofiles|date = 7 April 2009}}</ref><ref name="Incomplete">{{Cite web|url = http://www.ae.illinois.edu/m-selig/ads/aircraft.html|title = The Incomplete Guide to Airfoil Usage|access-date = 3 November 2012|last = Lednicer|first = David|year = 2010|archive-date = 20 April 2010|archive-url = https://web.archive.org/web/20100420012244/http://www.ae.illinois.edu/m-selig/ads/aircraft.html|url-status = dead}}</ref>
==Design and development==
The SF-2A Cygnet is a development of the earlier [[Sisler SF-2 Whistler]] introduced in 1973. The design features a [[strut-braced]] [[shoulder-wing]], a two-seats-in-[[side-by-side configuration]] enclosed cockpit under a [[bubble canopy]], fixed [[conventional landing gear]] and a single engine in [[tractor configuration]].<ref name="Aerocrafter" /><ref name="KitplanesJan2003" /><ref name="AF" />
The aircraft is made from wood, [[4130 steel]] tubing and covered in [[Aircraft dope|doped]] [[aircraft fabric]]. Its {{convert|30|ft|m|1|abbr=on}} span wing employs a [[NACA airfoil|NACA 3413]] [[airfoil]], has an area of {{convert|125|sqft|m2|abbr=on}} and is supported by a single strut with a [[jury strut]]. The cockpit is {{convert|39|in|cm|0|abbr=on}} wide and has a baggage compartment with a limit of {{convert|70|lb|kg|0|abbr=on}}, located behind the seats. The aircraft's recommended engine power range is {{convert|60|to|82|hp|kW|0|abbr=on}} and standard engines used include the {{convert|82|hp|kW|0|abbr=on}} Volkswagen [[four-stroke]] powerplant. Construction time from the supplied kit is estimated as 1700–1800 hours.<ref name="Aerocrafter" /><ref name="KitplanesJan2003" /><ref name="Incomplete" />
The Cygnet won a design award at the [[EAA Annual Convention and Fly-In]] in 1973.<ref name="Aerocrafter" />
==Operational history==
[[File:Sisler SF-2A Cygnet G-BYYC (24049082708).jpg|thumb|SF-2A Cygnet]]
By January 2003, 100 examples had been reported as completed and flown.<ref name="KitplanesJan2003" />
In July 2016 a total of 19 SF-2A Cygnets were [[Aircraft registration|registered]] in the United States with the [[Federal Aviation Administration]], four with [[Transport Canada]] and seven with the [[Civil Aviation Authority (United Kingdom)|Civil Aviation Authority]] in the [[United Kingdom]].<ref name="FAAReg">{{cite web|url = http://registry.faa.gov/aircraftinquiry/AcftRef_Results.aspx?Mfrtxt=&Modeltxt=SF-2A&PageNo=1|title = Make / Model Inquiry Results|access-date = 21 July 2016|last = [[Federal Aviation Administration]]|date = 21 July 2016}}</ref><ref name="TCCAR">{{cite web|url=http://wwwapps.tc.gc.ca/Saf-Sec-Sur/2/CCARCS-RIACC/RchSimpRes.aspx?cn=%7c%7c&mn=%7cSF2A%7c&sn=%7c%7c&on=%7c%7c&m=%7c%7c |title=Canadian Civil Aircraft Register |access-date=21 July 2016 |last=[[Transport Canada]] |date=21 July 2016 }}</ref><ref name="GINFO">{{cite web|url = http://publicapps.caa.co.uk/modalapplication.aspx?catid=1&pagetype=65&appid=1&mode=summary&aircrafttype=SF-2A|title = GINFO Search Results Summary|access-date = 21 July 2016|last = [[Civil Aviation Authority (United Kingdom)]]|date = 21 July 2016}}</ref>
In a 2020 review, AVweb writer Paul Dye concluded, "Flying a piece of history (and with a forward swept wing, something fairly unique!) is always fun. Just like all strange meat gets described as "tasting like chicken", it is easy to describe airplanes like this as flying "like a Cub"—and it’s true, in the sense that it is well-mannered and easy to steer around the sky. Yes, that visibility at the start of a turn is going to take a little getting used to, as is the landing attitude. But if you take the time to get it figured out, the Cygnet is a nice little airplane with a Midwest tradition. Honest, straightforward, and enjoyable.".<ref name="Spangler22Dec20">{{cite web|url= https://www.avweb.com/features/cygnet-distinction/|title= Cygnet Distinction|access-date= 15 December 2020|last= Dye|first= Paul|work= AVweb|date= 22 December 2020|archive-url= https://web.archive.org/web/20201223132523/https://www.avweb.com/features/cygnet-distinction/|archive-date= 23 December 2020|url-status= live}}</ref>
<!-- ==Variants== -->
<!-- ==Aircraft on display== -->
==Specifications (SF-2A Cygnet) ==
[[File:G-BWFN Sisler SF-2A Cygnet (9679534921).jpg|thumb|right|SF-2A Cygnet]]
{{Aircraft specs
|ref=Kitplanes and Purdy<ref name="Aerocrafter" /><ref name="KitplanesJan2003" />
|prime units?=imp<!-- imp or kts first for US aircraft, and UK aircraft pre-metrification, met(ric) first for all others. You MUST choose a format, or no specifications will show -->
<!--
General characteristics
-->
|genhide=
|crew=one
|capacity=one passenger
|length m=
|length ft=19
|length in=
|length note=
|span m=
|span ft=30
|span in=
|span note=
|height m=
|height ft=5.8
|height in=
|height note=
|wing area sqm=
|wing area sqft=125
|wing area note=
|aspect ratio=
|airfoil=[[NACA airfoil|NACA 3413]]
|empty weight kg=
|empty weight lb=585
|empty weight note=
|gross weight kg=
|gross weight lb=1100
|gross weight note=
|fuel capacity={{convert|15|u.s.gal}}
|more general=
<!--
Powerplant
-->
|eng1 number=1
|eng1 name=[[Volkswagen air-cooled engine]]
|eng1 type=four cylinder, 1835 cc, [[four stroke]] automotive conversion
|eng1 kw=<!-- prop engines -->
|eng1 hp=82<!-- prop engines -->
|prop blade number=
|prop name=
|prop dia m=
|prop dia ft=
|prop dia in=
|prop note=
<!--
Performance
-->
|perfhide=
|max speed kmh=
|max speed mph=108
|max speed kts=
|max speed note=
|cruise speed kmh=
|cruise speed mph=100
|cruise speed kts=
|cruise speed note=
|stall speed kmh=
|stall speed mph=48
|stall speed kts=
|stall speed note=
|never exceed speed kmh=
|never exceed speed mph=
|never exceed speed kts=
|never exceed speed note=
|range km=
|range miles=390
|range nmi=
|range note=
|endurance=
|ceiling m=
|ceiling ft=
|ceiling note=
|g limits=
|roll rate=
|glide ratio=
|climb rate ms=
|climb rate ftmin=580
|climb rate note=
|time to altitude=
|sink rate ms=
|sink rate ftmin=
|sink rate note=
|lift to drag=
|wing loading kg/m2=
|wing loading lb/sqft=
|wing loading note=
|power/mass=
|thrust/weight=
|more performance=
|avionics=
}}
==References==
{{reflist}}
==External links==
*{{commons category-inline}}
{{Viking Aircraft}}
[[Category:Homebuilt aircraft]]
[[Category:Single-engined tractor aircraft]]