Viper Aircraft ViperJet

{{Short description|American homebuilt sport aircraft}}  {{Infobox aircraft | name = ViperJet | logo = | logo_size = | image = | alt = | caption = | long_caption = | other_names = | aircraft_type = High performance sport and aerobatic | aim = | outcome = | related = | national_origin = United States | manufacturer = Viper Aircraft | design_group = | designer = Scott Hanchette | builder = | issuer = | status = | owners = | primary_user = | more_users = | service = | major_applications = | proposals = | prototypes = | number_built = | construction_number = | civil_registration = | military_serial = | radio_code = | requirement = | aircraft_carried = | flights = | total_hours = | total_distance = | construction_date = | introduction = | retired = | first_flight = October 1999 | initiated = | in_service = | last_flight = | expected = | developed_from = Viper Aircraft Viperfan | variants = | developed_into = | preservation = | fate = | predecessors = | successors = | concluded = }}

The '''Viper Aircraft ViperJet''' is a small homebuilt jet aircraft by Viper Aircraft Corporation. It is a conventional, low-wing monoplane with swept wings and tail and two seats in tandem under a bubble canopy. The jet intakes are located at the sides of the fuselage and the tricycle undercarriage is retractable. Construction throughout is of composite materials.<ref name="maiden">{{Citation | title = ViperJet kit aircraft makes maiden flight | url = https://www.flightglobal.com/news/articles/viperjet-kit-aircraft-makes-maiden-flight-58059/ | newspaper = Flight international | date = 10 November 1999 | publisher = Flight global | quote = The composite ViperJet…}}.</ref><ref name="WDLA11">{{Citation | last1 = Bayerl | first1 = Robby | first2 = Martin | last2 = Berkemeier | title = World Directory of Leisure Aviation | year = 2011–2012 | page = 126 | publisher = WDLA | place = Lancaster, UK | ISSN = 1368-485X|display-authors=etal}}</ref>

==Development== Originally conceived to use a piston engine driving a five- or six-blade pusher propeller, brothers Scott and Dan Hanchette commenced work on the prototype, then known as the ViperFan,<ref name="Freeze 10C">Freeze 2005, p. 10C</ref> in February 1996.<ref name= "Saywers 14">Saywers 2006, p. 14</ref> However, concerns about the difficulty and cost associated with eliminating vibration from the drivetrain led the Hanchettes to choose turbojet propulsion instead, and they installed a Turbomeca Marboré engine in place of the Continental flat-6 they had originally envisaged as a powerplant.<ref name="Freeze 10C" />

The Viperjet prototype flew late in October 1999.<ref name="maiden"/> and made its public debut at EAA AirVenture Oshkosh in 2000.<ref name="Hitchman">Hitchman 2000, p. 44.</ref> The Hanchette brothers, however, were unhappy with both the low power<ref name="Saywers 1">Saywers 2006, p. 1</ref> and the high fuel consumption<ref name="Freeze 11C">Freeze 2005, p.11C</ref> of the Turbomeca engine, and soon swapped it for a General Electric T58 turboshaft engine with the power turbine removed,<ref name="Freeze 11C" /> turning it into a turbojet. While this worked, it still did not produce as much thrust as the Hanchettes hoped for, and eventually, they selected the General Electric J85.<ref name= "Freeze 11C" /> With this engine producing around four times the thrust of the previous powerplants tested in the Viper, the Hanchettes substantially redesigned the aircraft, dubbing the J85-powered version the '''MKII'''.<ref name= "Freeze 11C"/> The prototype was dismantled and rebuilt, with parts of the canopy and fuselage center section all that remained of the original design.<ref name ="Freeze 11C"/> The slightly larger MKII also features a pressurized cabin,<ref name = "Joshi">Joshi 2007, p. B6</ref> nearly three times the fuel tankage,<ref name = "White 11">White 2006, p. 11.</ref> stronger undercarriage,<ref name="White 11"/> and optional tip tanks.<ref name="White 11"/> The MKII prototype flew on 12 June 2005 and Viper Aircraft offered replacement MKII parts to all customers who had purchased kits of the original version,<ref name="Freeze 11C" /> now dubbed the MKI.

In 2006, the base MKII kit cost US$182,000, but since builders can purchase additional components already pre-made by Viper Aircraft, customers spent an average of $350,000 on their kits.<ref name="Saywers 1"/> They would then have to spend approximately another $300,000<ref name="Saywers 1"/> and around 3,000 to 3,500 hours to complete the aircraft.<ref name = "Saywers 14"/> The company also offers customers a builder assistance program to help them assemble the major airframe components and a training program to help them learn to fly their ViperJet once it is complete. Zero Gravity Builders provides builder assistance for the ViperJet MKII, ViperJet LXR and Viper FanJet.<ref name = "White 12">White 2006, p. 12</ref> Viper Aircraft had sold 21 kits by September 2006.<ref name = "Saywers 14" />

In 2008, Viper Aircraft announced an enlarged, turbofan-powered follow-on design as the Viper Aircraft FanJet. The company has also proposed a military trainer version of the ViperJet, as well as a UAV version.<ref name = "White 13">White 2006, p. 13</ref>

==Operational history== By April 2020 seven examples had been registered in the United States with the Federal Aviation Administration.<ref name="FAAReg">{{cite web|url = http://registry.faa.gov/aircraftinquiry/AcftRef_Results.aspx?Mfrtxt=&Modeltxt=VIPERJET&PageNo=1|title = Make / Model Inquiry Results|access-date = 8 April 2020|last = Federal Aviation Administration|author-link = Federal Aviation Administration|date = 27 October 2012}}{{Dead link|date=January 2026 |bot=InternetArchiveBot }}</ref>

==Specifications (MKII, preliminary specifications) ==

{{Aircraft specs |ref=White 2006, p.13 |prime units? = imp |crew=One pilot |capacity=2 (1 pilot & 1 passenger) |length m=7.80 |length ft=25 |length in=6 |span m=8.48 |span ft=27 |span in=10 |empty weight kg=1,452 |empty weight lb=3,200 |gross weight kg=2,320 |gross weight lb=5,100 |eng1 number=1 |eng1 name=General Electric CJ-610 |eng1 kn=12.7 |eng1 lbf=2,850 |max speed kmh= 804-845 |max speed mph= 500-525 |cruise speed kmh=603 |cruise speed mph=375 |stall speed kmh=130 |stall speed mph=80 |range km=1,480 |range miles=920 |ceiling m= 10,500 |ceiling ft= 35,000 |climb rate ms=61 |climb rate ftmin=12,000 }}

==See also== {{Aircontent| |related= |similar aircraft= |lists= * List of very light jets |see also= }}

==References==

===Notes=== {{Reflist}}

===Bibliography=== {{refbegin}} * {{cite news |last=Freeze |first=Di |title=The Path to the Viperjet MkII – The Trickest Jet on the Block | work = Pacific Northwest Aviation & Business Journal |publisher= Airport Journals | volume= 4 | issue= 10 | date = November 2005 |pages= 8C–14C}} * {{cite magazine |last=Hitchman |first=Nigel |title=Travelling Light |magazine=Flight International |date = 5–11 September 2000 |pages=44–46 |url=http://www.flightglobal.com/pdfarchive/view/2000/2000-1%20-%200916.html | access-date = 2009-02-21}} * {{cite news |first=Pratik |last=Joshi |title=The right brothers |work=Tri-City Herald |date= 21 October 2007 |pages=B5–B6 }} * {{cite news |last=Saywers |first=Karisa |title=Local kit plane company provides opportunity for aircraft ownership |work=Tri-Cities Area Journal of Business |volume=5 |issue=9 |date=September 2006 |pages=1, 14}} * {{cite magazine |title= ViperJet kit aircraft makes maiden flight |magazine= Flight International |date = 10–16 November 1999 |page = 32 |url= http://www.flightglobal.com/FlightPDFArchive/1999/1999%20-%203319.PDF | format = PDF | access-date = 2009-02-21 | ref = {{SfnRef | Flight | 1999}}}} * {{cite magazine |last= White |first= Diane |title= The ViperJet MKII |magazine= Twin & Turbine |date= February 2006 | pages = 8–13}} {{refend}}

==External links== {{Commons category inline|Viperjet}}

ViperJet Category:1990s United States sport aircraft Category:Homebuilt aircraft Category:Single-engined jet aircraft Category:Low-wing aircraft Category:Aircraft first flown in 1999