De Havilland Canada DHC-6 Twin Otter
{{Short description|Utility transport aircraft family by de Havilland Canada}}
{{lowercase title|de Havilland Canada DHC-6 Twin Otter}}
{{Use Canadian English|date=February 2023}}
{{Use dmy dates|date=February 2023}}
{{Infobox aircraft
| name = DHC-6 Twin Otter
| image = File:WinAir De Havilland Canada DHC-6-300 Twin Otter Breidenstein.jpg
| caption = Winair DHC-6 Twin Otter landing at Gustaf III Airport
| type = Utility aircraft
| manufacturer = de Havilland Canada
Viking Air
| designer =
| first_flight = 20 May 1965
| introduction = 1966
| retired =
| primary_user =
| more_users =
| produced = 1965–1988 (Series 100–300)
2008–present (Series 400)
2023–present (Series 300-G)
| number_built = December 2019: {{#expr:844+150}}
(844 DHC, 150 Viking){{cite web |url= http://www.twinotterarchive.com/DHC-6_Index_new.html |title= Twin Otter Archive |date= August 2019 |author1= Mike Ody |author2= Erik Johannesson |author3= Ian Macintosh |author4= Neil Aird}}
| developed_from = de Havilland Canada DHC-3 Otter
| variants =
| developed_into =
}}
The de Havilland Canada DHC-6 Twin Otter is a Canadian STOL (Short Takeoff and Landing) utility aircraft developed by de Havilland Canada in the mid-1960s and still in production today. Built by De Havilland Canada from 1965 to 1988, Viking Air purchased the type certificate and restarted production in 2008, before re-adopting the DHC name in 2022. In 2023 DHC restarted production of the 300 series, in addition to the Series 400 produced by Viking.
The aircraft's fixed tricycle undercarriage, STOL capabilities, twin turboprop engines and high rate of climb have made it a successful commuter airliner, typically seating 18–20 passengers, as well as a cargo and medical evacuation aircraft. In addition, the Twin Otter has been popular with commercial skydiving operations, and is used by the United States Army Parachute Team and the 98th Flying Training Squadron of the United States Air Force.
Design and development
File:De Havilland Canada DHC-6-200 Twin Otter, Fayard Enterprises AN1275854.jpg
Development of the aircraft began in 1964, with the first flight on 20 May 1965. A twin-engine replacement for the single-engine DHC-3 Otter retaining the DHC-3's STOL qualities, its design features included double-slotted trailing-edge flaps and ailerons that work in unison with the flaps to boost STOL performance. The availability of the {{convert|550|shp|lk=in}} Pratt & Whitney Canada PT6A-20 turboprop in the early 1960s made the concept of a twin feasible. A DHC-3 Otter with its piston engine replaced with two PT6A-4Power – The Pratt & Whitney Canada Story, Kenneth H. Sullivan and Larry Milberry, CANAV Books 1989, {{ISBN|0-921022-01-8}}, p.146 engines had already flown in 1963. It had been extensively modified for STOL research.{{Cite web | url=https://www.flightglobal.com/pdfarchive/view/1963/1963%20-%200071.html?search=january%20otter%20stol |title = De havilland | 1963 | 0071 | Flight Archive}} To bush plane operators, the improved reliability of turboprop power and the improved performance of a twin-engine configuration made it an immediately popular alternative to the piston-powered Otter which had been flying since 1951.
File:Vancouver to Victoria. West Coast Air De Havilland DHC-6 Twin Otter floatplane -2.jpg
File:De Havilland Canada DHC-6-300 Twin Otter, WinAir AN2097069.jpg
The first six aircraft produced were designated Series 1, indicating that they were prototype aircraft. The initial production run consisted of Series 100 aircraft, serial numbers seven to 115 inclusive. In 1968, Series 200 production began with serial number 116. Changes made at the beginning of Series 200 production included improving the STOL performance, adding a longer nose that was equipped with a larger baggage compartment (except for aircraft fitted with floats), and fitting a larger door to the rear baggage compartment. All Series 1, 100, and 200 aircraft and their variants (110, 210) were fitted with the {{cvt|550|shp}} PT6A-20 engines.
In 1969, the Series 300 was introduced, beginning with serial number 231. Both aircraft performance and payload were improved by fitting more powerful PT6A-27 engines. This was a {{cvt|680|hp}} engine that was flat rated to {{cvt|620|hp}} for use in the Series 300 Twin Otter. The Series 300 proved to be the most successful variant by far, with 614 Series 300 aircraft and their subvariants (Series 310 for United Kingdom operators, Series 320 for Australian operators, etc.) sold before production in Toronto by de Havilland Canada ended in 1988.
In 1972, its unit cost was US$680,000,{{cite magazine |url= https://www.flightglobal.com/pdfarchive/view/1972/1972%20-%202020.html |title= Airliner price index |magazine= Flight International |date= 10 August 1972 |page= 183}}
In 1976, a new -300 would have cost $700,000 (${{inflation|USD|0.7|r=1|1976|2017}} million 31 years later) and is still worth more than $2.5 million in 2018 despite the -400 introduction, many years after the -300 production ceased.{{cite news |url= http://www.aircraftvaluenews.com/dash8-400-values-face-some-uncertainty-as-viking-takes-over/ |title= Dash8-400 Values Face Some Uncertainty as Viking Takes Over |author= Aircraft Value News |date= 26 November 2018}} 844 had been produced by the time the first production end run ended in 1988.{{Cite web |title=UV-18A Twin Otter - Military Aircraft |url=https://man.fas.org/dod-101/sys/ac/uv-18.htm |access-date=2023-11-01 |website=man.fas.org}}{{Cite web |last=Hemmerdinger |first=Jon |title=De Havilland resumes Twin Otter 300 production with new variant |url=https://www.flightglobal.com/airframers/de-havilland-resumes-twin-otter-300-production-with-new-variant/153788.article |access-date=2023-11-01 |website=Flight Global |language=en}}
=New production=
After Series 300 production ended, the remaining tooling was purchased by Viking Air of Victoria, British Columbia, which manufactures replacement parts for out-of-production de Havilland Canada aircraft. On 24 February 2006, Viking purchased the type certificates from Bombardier Aviation for all out-of-production de Havilland Canada aircraft (DHC-1 through DHC-7).
[http://aiabc.com/artman/publish/printer_47.shtml "Viking Acquires De Havilland Type Certificates."] {{Webarchive|url=https://web.archive.org/web/20060824095652/http://aiabc.com/artman/publish/printer_47.shtml |date=24 August 2006 }} aiabc.com, 24 February 2006. Retrieved: 15 May 2010. The ownership of the certificates gives Viking the exclusive right to manufacture new aircraft.
On 17 July 2006, at the Farnborough Airshow, Viking Air announced its intention to offer a Series 400 Twin Otter. On 2 April 2007, Viking announced that with 27 orders and options in hand, it was restarting production of the Twin Otter, equipped with more powerful Pratt & Whitney Canada PT6A-34 engines.[http://www.flightglobal.com/Articles/2007/04/02/212989/viking-restarts-twin-otter-production.html "Viking restarts Twin Otter production."] flightglobal.com, 2 April 2007. Retrieved: 15 May 2010. As of November 2007, 40 firm orders and 10 options had been taken and a new final assembly plant was established in Calgary, Alberta.Sarsfield, Kate. [http://www.flightglobal.com/articles/2010/02/03/337923/viking-twin-otter-series-400-certification-approaches.html "Viking Twin Otter Series 400 certification approaches."] Flightglobal, 3 February 2010. Retrieved: 15 May 2010.[http://www.vikingair.com/content.aspx?id=82 "News releases."] {{Webarchive|url=https://web.archive.org/web/20100908101652/http://www.vikingair.com/content.aspx?id=82 |date=8 September 2010 }} Viking Air. Retrieved: 15 May 2010. Zimex Aviation of Switzerland received the first new production aircraft, serial number 845, in July 2010.
[http://www.zimex.ch/home/fleet/twin-otter.aspx "Twin Otter – Zimex Aviation."] {{Webarchive|url=https://web.archive.org/web/20080501155523/http://www.zimex.ch/home/fleet/twin-otter.aspx |date=1 May 2008}} zimex.ch. Retrieved: 15 May 2010.
{{cite news |last=Jang |first=Brent |url=https://www.theglobeandmail.com/report-on-business/careers/the-rebirth-of-a-canadian-icon/article4319246 |title=The rebirth of a Canadian icon. |newspaper=The Globe and Mail |date=14 May 2010|access-date=8 August 2012}} By mid-2014, Viking had built 55 new aircraft at its Calgary facility. The production rate as of summer 2014 was about 24 aircraft per year. In April 2015, Viking announced a reduction of the production rate to 18 aircraft per year.{{cite web|url=http://www.ainonline.com/aviation-news/business-aviation/2015-04-07/viking-air-slashes-twin-otter-production-lays-116 |title=Viking Air Slashes Twin Otter Production, Lays Off 116|work=Aviation International News|access-date=3 July 2015}} On 17 June 2015, Viking announced a partnership with a Chinese firm, Reignwood Aviation Group; the group would purchase 50 aircraft and become the exclusive supplier of new Series 400 Twin Otters in China.
File:First Flight Twin Otter Series 400 C-FDHT (cropped).jpg at Victoria Airport, 1 October 2008]]
Major changes introduced with the Series 400 include Honeywell Primus Apex fully integrated avionics, deletion of the AC electrical system, modernization of the electrical and lighting systems, and use of composites for non load-bearing structures such as doors.Phelps, Mark. [http://www.flyingmag.com/news/1156/updated-twin-otter-takes-off.html "Updated Twin Otter Takes Off."] {{Webarchive|url=https://web.archive.org/web/20081024135619/http://www.flyingmag.com/news/1156/updated-twin-otter-takes-off.html |date=24 October 2008 }} flyingmag.com, 16 October 2008. Retrieved: 15 May 2010.
The 100th Series 400 Twin Otter (MSN 944) was displayed at the July 2017 EAA AirVenture Oshkosh. At the time 38% were operated as regional airliners, 31% were in military aviation use, 26% in industrial support and 5% were in private air charter. Seventy were on regular landing gear wheels, 18 were configured as straight or amphibious floatplanes, 10 had tundra tires and two had wheel skis.{{cite press release |url= https://www.vikingair.com/viking-news/media-centre/100th-viking-production-series-400-twin-otter-display-eaa-airventure-2017 |title= 100th Viking Production Series 400 Twin Otter on Display at EAA Airventure 2017 |date= 21 July 2017 |publisher= Viking Air |url-status= dead |archive-url= https://web.archive.org/web/20170728163011/https://www.vikingair.com/viking-news/media-centre/100th-viking-production-series-400-twin-otter-display-eaa-airventure-2017 |archive-date= 28 July 2017}}
In 2019, Viking started making plastic components for the Twin Otter by 3D printer to help reduce cost.{{cite news |last1=Ballah |first1=Brett |title=De Havilland owner believes renewed focus will increase Dash 8 market share |url=https://westernaviationnews.com/2019/08/28/de-havilland-owner-believes-renewed-focus-will-increase-dash-8-market-share/ |access-date=19 December 2019 |work=Western Aviation News |date=28 August 2019 |language=en |archive-date=19 December 2019 |archive-url=https://web.archive.org/web/20191219211954/https://westernaviationnews.com/2019/08/28/de-havilland-owner-believes-renewed-focus-will-increase-dash-8-market-share/ |url-status=dead }}
Twin Otter production was suspended in 2019 during the COVID-19 pandemic. In July 2022, DHC announced that it was reviewing the program and supply chain, with a decision on when to resume production expected "in the near future".{{cite news |last=Hemmerdinger |first=Jon |title=De Havilland reviewing Twin Otter and Dash 8 programmes, considering updates |url=https://www.flightglobal.com/farnborough-2022/de-havilland-reviewing-twin-otter-and-dash-8-programmes-considering-updates/149479.article |work=Flight Global |date=19 July 2022 }}
In 2023, its equipped price was $7.25M.{{cite news |url= https://infogram.com/bca-table-2023-turboprops-1ho16vorwrxm84n |title=Purchase planning handbook – turboprops table |date= Second Quarter 2023|work=Business & Commercial Aviation}}
In June 2023 Viking, now operating as De Havilland Canada started production of new DHC-6 Classic 300-G.
Operational history
File:Aerovías DAP-TWIN otter (cropped).jpg DHC-6 Series 300 at Puerto Williams, Chile]]
File:This is a perfectly normal approach for a Twin Otter.jpg, Australia]]
File:TMA DHC-6 Twin Otter at Velana International Airport, May 2017.jpg Twin Otter at Velana International Airport, Maldives]]
File:Maldivian DHC-6 Twin Otter water landing.webm
File:Twin Otter 4 1997-08-02.jpg at the graves of seamen who were part of Franklin's lost expedition (Nunavut, Canada) circa 1997. Note the tundra tires.]]
File:Plane arrival at Barra Airport.jpg's sandy beach runway]]
Twin Otters could be delivered directly from the factory with floats, skis, or tricycle landing gear fittings, making them adaptable bush planes for remote and northern areas. Areas including Canada and the United States, (specifically Alaska) had much of the demand. Many Twin Otters still serve in the Arctic and subarctic, but they can also be found in Africa, Australia, Asia, Antarctica, and other regions where bush planes are the optimum means of travel. Their versatility and manoeuvrability have made them popular in areas with difficult flying environments such as Papua New Guinea. In Norway, the Twin Otter paved the way for the network of short-field airports, connecting rural areas with larger towns. The Twin Otter showed outstanding reliability, and remained in service until 2000 on certain routes. Widerøe of Norway was, at one time, the world's largest operator of Twin Otters. During one period of its tenure in Norway, the Twin Otter fleet achieved over 96,000 cycles (take-off, flight, and landing) per year.{{citation needed|date=April 2018}}
A number of commuter airlines in the United States got their start by operating Twin Otters in scheduled passenger operations. Houston Metro Airlines (which later changed its name to Metro Airlines) constructed their own STOLport airstrip with a passenger terminal and maintenance hangar in Clear Lake City, Texas, near the Johnson Space Center. The Clear Lake City STOLport was specifically designed for Twin Otter operations. According to the February 1976 edition of the Official Airline Guide, Houston Metro operated 22 round-trip flights every weekday at this time between Clear Lake City (CLC) and Houston Intercontinental Airport, now George Bush Intercontinental Airport, in a scheduled passenger airline shuttle operation.North American Official Airline Guide (OAG), February 1976 edition Houston Metro had agreements in place for connecting passenger feed services with Continental Airlines and Eastern Air Lines at Houston Intercontinental, with this major airport having a dedicated STOL landing area at the time specifically for Twin Otter flight operations. The Clear Lake City STOLport is no longer in existence.
The Walt Disney World resort in Florida was also served with scheduled airline flights operated with Twin Otter aircraft. The Walt Disney World Airport, also known as the Lake Buena Vista STOLport, was a private airfield constructed by The Walt Disney Company with Twin Otter operations in mind. In the early 1970s, Shawnee Airlines operated scheduled Twin Otter flights between the Disney resort and nearby Orlando Jetport, now Orlando International Airport, as well as to Tampa International Airport. This service by Shawnee Airlines is mentioned in the "Air Commuter Section" of the 6 September 1972 Eastern Air Lines system timetable as a connecting service to and from Eastern flights.{{cite web|url=http://www.departedflights.com |title=index |website=Departedflights.com |date=14 April 2017 |access-date=26 April 2017}} This STOL airfield is no longer in use.
Another commuter airline in the United States, Rocky Mountain Airways, operated Twin Otters from the Lake County Airport in Leadville, Colorado. At an elevation of {{cvt|9,927|ft|order=flip}} above mean sea level, this airport is the highest airfield in the United States ever to have received scheduled passenger airline service, thus demonstrating the wide-ranging flight capabilities of the Twin Otter. Rocky Mountain Airways went on to become the worldwide launch customer for the larger, four-engine de Havilland Canada Dash 7 STOL turboprop, but continued to operate the Twin Otter, as well.
Larger scheduled passenger airlines based in the United States, Canada, Mexico, the Caribbean and Australia, particularly jetliner operators, also flew Twin Otters, with the aircraft providing connecting feeder service for these airlines. Jet aircraft operators which also flew the Twin Otter included Aeronaves de Mexico, Air BC, Alaska Airlines, ALM Antillean Airlines, Ansett Airlines, Cayman Airways, Frontier Airlines, LIAT, Norcanair, Nordair, Ozark Air Lines, Pacific Western Airlines, Quebecair, South Pacific Island Airways, Time Air, Transair, Trans Australia Airlines (TAA), Wardair and Wien Air Alaska.[http://www.timetableimages.com/] airline system timetables[http://www.departedflights.com/] airline system timetables & OAG flight guides In many cases, the excellent operating economics of the Twin Otter allowed airlines large and small to provide scheduled passenger flights to communities that most likely would otherwise never have received air service.
Twin Otters are also a staple of Antarctic transportation.[https://www.nsf.gov/od/lpa/news/press/01/pr0129.htm "NSF PR 01-29 — Civilian Aircraft to Evacuate South Pole Patient"] nsf.gov. Retrieved: 15 May 2010. Four Twin Otters are employed by the British Antarctic Survey on research and supply flights, and several are employed by the United States Antarctic Program via contract with Kenn Borek Air. On 24–25 April 2001, two Twin Otters performed the first winter flight to Amundsen–Scott South Pole Station to perform a medical evacuation.[http://www.70south.com/resources/evacuations/2001-southpole "2001—Doctor Evacuated from the South Pole."] {{Webarchive|url=https://archive.today/20060315230338/http://www.70south.com/resources/evacuations/2001-southpole |date=15 March 2006}} www.70south.com. Retrieved: 15 May 2010.Williams, Jeff. [https://www.usatoday.com/news/science/cold-science/doctor/2001-04-27-pilot.htm "Pilot says pole flight wasn't his most challenging."] usatoday.com.[https://web.archive.org/web/20071018150856/http://www.cbc.ca/news/story/2001/05/03/antarctic_bas_010503.html "Pilots return after historic South Pole rescue."]cbc.ca/news. Retrieved: 15 May 2010.[http://www.antarctica.ac.uk/living_and_working/aircraft_and_vehicles/aircraft/index.php "Aircraft in Antarctica: British Antarctic Survey."] {{Webarchive|url=https://web.archive.org/web/20080129092148/http://www.antarctica.ac.uk/living_and_working/aircraft_and_vehicles/aircraft/index.php |date=29 January 2008}} antarctica.ac.uk. Retrieved: 31 December 2007.
On 21–22 June 2016, Kenn Borek Air's Twin Otters performed the third winter evacuation flight to Amundsen–Scott South Pole Station to remove two people for medical reasons.{{cite news|url=http://www.cbc.ca/news/canada/calgary/kenn-borek-air-south-pole-june-22-1.3646966 |title=Calgary crew evacuates pair from South Pole in daring Antarctic rescue|website=CBC News|access-date=23 June 2016}}
The Argentine Air Force has used the Twin Otter in Antarctica[http://www.fuerzaaerea.mil.ar/material/images/foto_twinotter.png "Official picture."] {{Webarchive|url=https://web.archive.org/web/20110718102115/http://www.fuerzaaerea.mil.ar/material/images/foto_twinotter.png |date=18 July 2011}} fuerzaaerea.mil. Retrieved: 15 May 2010. since the 1970s, with at least one of them deployed year-round at Marambio Base.Hulcazuk, Sergio. [http://www.aeroespacio.com.ar/site/anteriores/520-528/524/castor.htm "Twin Otter: El castor patagonico."] {{Webarchive|url=https://web.archive.org/web/20100813230144/http://www.aeroespacio.com.ar/site/anteriores/520-528/524/castor.htm |date=13 August 2010}} aeroespacio.com. Retrieved: 15 May 2010. The Chilean Air Force has operated the type since 1980, usually having an example based at Presidente Frei Antarctic base of the South Shetland Islands.
Alfredo Stroessner, Paraguayan head of state from 1954 until 1989, used a Twin Otter as a presidential aircraft; although the Twin Otter remained in the Paraguayan Air Force inventory after he was deposed, subsequent presidents switched to other, private aircraft for official duties.{{cite press release|url=https://www.ip.gov.py/ip/china-taiwan-dono-aeronave-a-la-fuerza-aerea-paraguaya/ |title=Tras dos décadas Paraguay vuelve a tener aeronave oficial para vuelo presidencial |date=10 December 2019 |access-date=6 May 2024 |publisher=Ministerio de Tecnologías de la Información y Comunicación |location=Asunción |language=Spanish}}
File:Kangerlussuaq-airport-air-greenland-dhc6.jpg Twin Otter at Kangerlussuaq Airport]]
As of August 2006, a total of 584 Twin Otter aircraft (all variants) remained in service worldwide. Major operators at the time included: Libyan Arab Airlines, Maldivian Air Taxi, Trans Maldivian Airways, Kenn Borek Air, and Grand Canyon Scenic Airlines. Some 115 airlines operated smaller numbers of the aircraft including Yeti Airlines in Nepal, Malaysia Airlines (which used the Twin Otter exclusively for passenger and freight transportation to the Kelabit Highlands region in Sarawak), and in the United Kingdom, the Scottish airline, Loganair which uses the aircraft to service the island of Barra in the Outer Hebrides. This daily scheduled service is unique as the aircraft lands on the beach and the schedule is partly influenced by the tide tables. Trials at Barra Airport with heavier planes than the Twin Otter, like the Short 360, failed because they sank in the sand. The Twin Otter is also used for landing at Juancho E. Yrausquin Airport, the world's shortest commercial runway, on the Caribbean island of Saba, Netherlands Antilles.
The Twin Otter has been popular with commercial skydiving operations. It can carry up to 22 skydivers to over {{cvt|17,000|ft|order=flip}} (a large load compared to most other aircraft in the industry); presently, the Twin Otter is used in skydiving operations in many countries. The United States Air Force operates three Twin Otters for the United States Air Force Academy's skydiving team.
On 26 April 2001, the first ever air rescue during polar winter from the South Pole occurred with a ski-equipped Twin Otter operated by Kenn Borek Air.{{cite web |url= http://www.stargate4173.com/Polar/PolarJournals/southPoleRescue.html |title= The Rescue of Dr. Ron Shemenski from the South Pole |author= Bob Antol |publisher= Bob Antol's Polar Journals |date= April 2001 |access-date= 23 January 2013}}{{cite news |url= http://www.nzherald.co.nz/world/news/article.cfm?c_id=2&objectid=185352 |title= Doctor rescued from Antarctica safely in Chile |date= 27 April 2001 |access-date= 23 January 2013|newspaper= New Zealand Herald }}{{cite news |url= http://edition.cnn.com/TRANSCRIPTS/0104/26/bn.02.html |title= Plane With Dr. Shemenski Arrives in Chile |date= 26 April 2001 |access-date= 23 January 2013 |author= Transcript |publisher= CNN }}
On 25 September 2008, the Series 400 Technology Demonstrator achieved "power on" status in advance of an official rollout.[http://www.vikingair.com/content.aspx?id=1742 "Viking Twin Otter Series 400 Achieves Power On."] {{Webarchive|url=https://web.archive.org/web/20100311032307/http://www.vikingair.com/content.aspx?id=1742 |date=11 March 2010}} vikingair.com, 25 September 2008. Retrieved: 15 May 2010.[http://www.canada.com/vancouversun/news/business/story.html?id=0b77b24c-42d4-45b4-a3d6-cf36ba3fdda9 "Twin Otter Shakes Its Wings Over Victoria Skies."] {{Webarchive|url=https://web.archive.org/web/20081011031801/http://www.canada.com/vancouversun/news/business/story.html?id=0b77b24c-42d4-45b4-a3d6-cf36ba3fdda9 |date=11 October 2008}} canada.com, 2 October 2008. Retrieved: 15 May 2010. The first flight of the Series 400 technical demonstrator, C-FDHT, took place 1 October 2008, at Victoria International Airport.Padfield, R. Randall and Matt Thurber. [http://www.ainonline.com/news/single-news-page/article/revived-twin-otter-makes-first-flight/ "Revived Twin Otter Makes First Flight."] {{Webarchive|url=https://web.archive.org/web/20081011004037/http://www.ainonline.com/news/single-news-page/article/revived-twin-otter-makes-first-flight/ |date=11 October 2008}} ainonline.com, 8 October 2008. Retrieved: 15 May 2010.[http://www.canada.com/victoriatimescolonist/news/story.html?id=4a051728-a3a4-40b0-9c96-3384f2b9690b "First Flight For New Twin Otter A "Boring" Success."] {{Webarchive|url=https://web.archive.org/web/20081002233110/http://www.canada.com/victoriatimescolonist/news/story.html?id=4a051728-a3a4-40b0-9c96-3384f2b9690b |date=2 October 2008}} canada.com, 1 October 2008. Retrieved: 15 May 2010.
Two days later, the aircraft departed Victoria, British Columbia for a ferry flight to Orlando, Florida, site of the 2008 National Business Aviation Association (NBAA) Conference and exhibition. The first new build Series 400 Twin Otter (SN 845) made its first flight on 16 February 2010, in Calgary, Alberta.[http://www.flightglobal.com/articles/2010/02/17/338513/twin-otter-series-400-completes-maiden-sortie.html "Twin Otter Series 400 completes maiden sortie."] flightglobal.com, 17 February 2010. Retrieved: 15 May 2010. Transport Canada presented Viking Air Limited with an amended DHC-6 Type Certificate including the Series 400 on 21 July 2010. Six years after, in July 2016, 100 series 400 have been delivered to 34 customers operating in 29 countries.{{cite press release |url= http://www.vikingair.com/viking-news/media-centre/viking-readies-100th-production-series-400-twin-otter-delivery |title= Viking Readies 100th Production Series 400 Twin Otter for Delivery |date= 12 July 2016 |publisher= Viking Air}}
In June 2017, 125 have been made since restarting production in 2010.{{cite news|url=https://www.flightglobal.com/news/articles/paris-viking-targets-china-russia-with-twin-otter-438659/|title=Viking targets China, Russia with Twin Otter|author=Jon Hemmerdinger|date=21 June 2017|work=Flightglobal}}
Variants
File:De Havilland Canada DHC-6-100 Twin Otter (N24HV, cn 109) (2-3-2024).jpg]]
File:DHC-300 Twin Otter 300 Air Seychelles.jpg de Havilland Canada DHC-6-300 Twin Otter on Bird Island, Seychelles]]
File:SeaborneTwinOtterSTT.jpg DHC-6-300 fitted with floats makes a water landing at Saint Thomas, U.S. Virgin Islands]]
;{{visible anchor|DHC-6 Series 100}} : Twin-engine STOL utility transport aircraft, powered by two {{cvt|550|shp}} Pratt & Whitney PT6A-20 turboprop engines.
;DHC-6 Series 110 : Variant of the Series 100 built to conform to BCAR (British Civil Air Regulations).
;{{Visible anchor|DHC-6 Series 200}} : Improved version.
;{{visible anchor|DHC-6 Series 300}} : Twin-engine STOL utility transport aircraft, powered by two {{cvt|680|shp}} (715 ESHP) Pratt & Whitney Canada PT6A-27 turboprop engines.
;DHC-6 Series 300M : Multi-role military transport aircraft. Two of these were produced as "proof-of-concept" demonstrators. Both have since been reverted to Series 300 conformity.
;{{visible anchor|DHC-6 Series 310}} : Variant of the Series 300 built to conform to BCAR (British Civil Air Regulations).
;DHC-6 Series 320 : Variant of the Series 300 built to conform to Australian Civil Air Regulations.
;DHC-6 Series 300S : Six demonstrator aircraft fitted with eleven seats, wing spoilers and an anti-skid braking system. All have since been reverted to Series 300 conformity.
;{{visible anchor|Viking Air DHC-6 Series 400}}
:Viking Air production, first delivered in July 2010, powered by two Pratt & Whitney Canada PT6A-34 engines, and available on standard landing gear, straight floats, amphibious floats, skis, wheel skis, or intermediate flotation landing gear ("tundra tires").
;Viking Air DHC-6 Series 400S Seaplane - never produced
: Viking Air seventeen-seat seaplane version of the Series 400 with twin floats and corrosion-resistance measures for the airframe, engines and fuels system. Customer deliveries planned from early 2017.{{cite magazine|magazine=Pilot|date=April 2016|title=New Twin Otter Seaplane launched|page=8|publisher=Archant Specialist}} {{cvt|500|lb|kg}} lighter than the 400.{{cite news |url= http://airinsight.com/2016/11/01/a-visit-with-viking/ |title= A Visit with Viking |publisher= Air Insight |date= 1 November 2016}}
;DHC-6 Classic 300-G : Updated DHC-6 Series 400, with an all-new interior and new flight deck featuring a glass cockpit.{{cite news|url=https://dehavilland.com/en/news/posts/de-havilland-canada-launches-the-DHC-6-twin-otter-classic-300-g |title= De Havilland Canada launches the DHC-6 Twin Otter Classic 300-G |publisher= De Havilland Aircraft of Canada |date= 19 June 2023}}
;{{visible anchor|CC-138}} : Twin-engine STOL utility transport, search and rescue aircraft for the Canadian Armed Forces Search and Rescue operations. Based on the Series 300 aircraft.
;UV-18A : Twin-engine STOL utility transport aircraft for the Alaska National Guard. Six built. It has been replaced by the Short C-23 Sherpa in United States Army service. In 2019 the United States Naval Research Laboratory added a UV-18A to the Scientific Development Squadron One (VXS-1) inventory.{{cite web|url=https://www.janes.com/article/88991/nrl-introduces-uv-18-twin-otter-aircraft-into-test-fleet |title=NRL introduces UV-18 Twin Otter aircraft into test fleet|author=Richard Scott|date=3 June 2019|access-date=28 February 2020}}
;UV-18B : Parachute training aircraft for the United States Air Force Academy. The United States Air Force Academy's 98th Flying Training Squadron maintains three
[http://www.afhra.af.mil/factsheets/factsheet.asp?id=11949 "94 FTS Fact Sheet."] {{Webarchive|url=https://web.archive.org/web/20160303192641/http://www.afhra.af.mil/factsheets/factsheet.asp?id=11949 |date=3 March 2016 }} afhra.af.mil. Retrieved: 12 August 2009. UV-18s in its inventory as free-fall parachuting training aircraft,[http://www.globalsecurity.org/military/systems/aircraft/uv-18.htm "UV-18."] globalsecurity.org. Retrieved: 12 August 2009. and by the Academy Parachute Team, the Wings of Blue, for year-round parachuting operations. Based on the Series 300 aircraft.
;UV-18C : United States Army designation for three Viking Air Series 400s delivered in 2013.{{cite web|url=https://www.army.mil/article/88332/Army_developing_new_fixed_wing_aircraft/|title=Army developing new fixed-wing aircraft|author=Kris Osborn|date=1 October 2012|work=army.mil|access-date=25 January 2015}}
Operators
{{Main|List of de Havilland Canada DHC-6 Twin Otter operators}}
File:Landing beach side, flying into St Barths, Oct 2014 (15531536397).jpg
In 2016, there were 281 Twin Otters in airline service with 26 new aircraft on order: 112 in North/South America, 106 in Asia Pacific and Middle East (16 orders), 38 in Europe (10 orders) and 25 in Africa.{{cite news |url= https://www.flightglobal.com/asset/12798 |archive-url= https://web.archive.org/web/20160822202659/https://www.flightglobal.com/asset/12798 |url-status= dead |archive-date= 22 August 2016 |title= World Airliner Census |date= 8 August 2016 |work= Flight Global}}
In 2018, a total of 270 Twin Otters were in airline service, and 14 on order: 111 in North/South America, 117 in the Asia Pacific and Middle East (14 orders), 26 in Europe and 13 in Africa.{{Cite web|url=https://www.flightglobal.com/asset/24536|archive-url=https://web.archive.org/web/20181106212640/https://www.flightglobal.com/asset/24536|url-status=dead|archive-date=6 November 2018|title=World Airline Census 2018|website=Flightglobal.com|access-date=27 August 2018}}
In 2020, there were a total of 315 Twin Otters worldwide with 220 in service, 95 in storage and 8 on order. By region there were 22 in Africa, 142 in Asia Pacific (8 orders), 37 in Europe, 4 in the Middle East and 110 in the Americas.{{cite web|url=https://archive.org/details/worldairlinecensus2020 |title=World Airliner Census 2020|access-date=17 February 2023}}
The Twin Otter has been popular not only with bush operators as a replacement for the single-engine de Havilland Canada DHC-3 Otter but also with other civil and military customers, with over 890 aircraft built. Many commuter airlines in the United States got their start by flying the Twin Otter in scheduled passenger operations.
| class="wikitable sortable" style="margin: 1em auto;"
|+Airlines with six aircraft or more (2020) ! scope="col" width="140" | Operator ! scope="col" width="2" | Total ! scope="col" width=''2" | In service ! scope="col" width="2" | Stored ! scope="col" width="125" | Country | ||||
| Trans Maldivian Airways | 84 | 75 | 9 | {{flaglist|Maldives}} |
| Kenn Borek Air | 15 | 11 | 4 | {{flaglist|Canada}} |
| Grand Canyon Airlines | 13 | 6 | 7 | {{flaglist|United States}} |
| Maldivian | 11 | 10 | 1 | {{flaglist|Maldives}} |
| Transwest Air | 9 | 9 | 0 | {{flaglist|Canada}} |
| Zimex Aviation | 9 | 7 | 2 | {{flaglist|Switzerland}} |
| AeroGeo | 8 | 0 | 8 | {{flaglist|Russia}} |
| Air Borealis (PAL Airlines) | 8 | 8 | 0 | {{flaglist|Canada}} |
| Air Adelphi | 7 | 6 | 1 | {{flaglist|Saint Vincent and the Grenadines|table=yes}} |
| Air Inuit | 7 | 7 | 0 | {{flaglist|Canada}} |
| LADE | 7 | 5 | 2 | {{flaglist|Argentina}} |
| Airfast Indonesia | 6 | 6 | 0 | {{flaglist|Indonesia}} |
| Aviastar Mandiri | 6 | 5 | 1 | {{flaglist|Indonesia}} |
| Manta Air | 6 | 5 | 1 | {{flaglist|Maldives}} |
| MASwings | 6 | 2 | 4 | {{flaglist|Malaysia}} |
| Merpati | 6 | 0 | 6 | {{flaglist|Indonesia}} |
Accidents and incidents
Specifications
File:De Havilland Canada UV-18A Twin Otter 3-view line drawing.png
| class="wikitable" |
| Series |
|---|
| Cockpit crew
| colspan=3 | 1–2 |
| Seating
| colspan=2 | 20 || 19 |
| Length
| 49 ft 6 in (15.09m) | colspan=2 | {{cvt|15.77|m|ftin|order=flip}} |
| Height
| colspan=3 | 19 ft 6 in / 5.94 m |
| Wing
| colspan=3 | {{cvt|19.81|m|ftin|order=flip}} span, {{cvt|39|m2|sqft|order=flip}} area ({{#expr:19.8/(39/19.8)round2}} AR) |
| Empty weight
| 5,850l lb / 2,653 kg || 7,415 lb / 3,363 kg || 7,100 lb / 3,221 kg (no accommodation) |
| MTOW
| 10,500 lb / 4763 kg | colspan=2 | 12,500 lb / 5,670 kg{{efn|military -400: 14,000 lb / 6350 kg}} |
| Payload
| 975 kg (2150 lb) over 1344 km (727 nm) | 1135 kg (2500 lb) over 1297 km (700 nm) | 1842 kg (4061 lb) over 185 km (100 nm) |
| Fuel capacity
| || || 378 US gal / 1466 L,{{efn|name=LRtank|89 US Gal / 336 L optional wingtip tank for 3,190 lb 1,447 kg of fuel}} 2,590 lb / 1,175 kg |
| Turboprops (×2)
| P&WC PT6A-20 || PT6A-27 || PT6A-34 |
| Unit Power
| 431 kW / 578shp || 460 kW / 620shp || {{cvt|750|hp|kW|0|order=flip}} |
| Max. Cruise
| 297 km/h / 160kn || 338 km/h / 182kn || {{cvt|182|knots|km/h|order=flip}} (FL100) |
| Takeoff to 50 ft
| || || STOL 1,200 ft / 366 m; CTOL 1,490 ft / 454 m;{{cite web |url= https://www.vikingair.com/sites/default/files/Viking-Twin-Otter-Series-400-Technical-Specifications-R-01-2018.pdf |title= Twin Otter Series 400 - Technical Specifications and Standard Equipment List |date= 26 July 2024 |publisher= Viking Aircraft }} |
| Landing from 50 ft |
| Stall Speed
| 65 mph || || |
| Ferry Range
| 771 nmi / 1,427 km || || 799 nmi / 1480 km{{efn|name=LRperf|989 nmi / 1832 km ferry range or 8.76 h of endurance with optional wingtip tanks}} |
| Endurance
| || || 6.94 h{{efn|name=LRperf}} |
| Ceiling
| colspan=3 | 25,000 ft / 7,620 m |
| Climb rate
| || colspan=2 | {{cvt|1,600|ft/min|m/s}} |
| FL100 fuel burn {{cvt|146|knots|km/h}} | colspan= 2 | || {{cvt|468.2|lb}}/hour |
| Power/mass
| {{cvt|{{#expr:578*2/10500round2}}|hp/lb}} || {{cvt|{{#expr:620*2/12500round2}}|hp/lb}} || {{cvt|{{#expr:750*2/12500round2}}|hp/lb}} |
= Table notes =
{{Notelist}}
See also
{{Portal|Aviation|Canada}}
{{aircontent|
|related=
|similar aircraft=
- Antonov An-28
- Britten-Norman Trislander
- CASA C-212 Aviocar
- Dornier 228
- Embraer EMB 110 Bandeirante
- GAF Nomad N24
- Harbin Y-12
- IAI Arava
- Let L-410 Turbolet
- PZL M28 Skytruck
- Short SC.7 Skyvan
|lists=
|see also=
}}
References
=Notes=
{{Reflist}}
=Bibliography=
- {{cite journal |last1=Harding|first1=Stephen|title=Canadian Connection: US Army Aviation's Penchant for Canadian Types |journal=Air Enthusiast |date=November–December 1999|issue=84|pages=72–74 |issn=0143-5450}}
- Hotson, Fred W. The de Havilland Canada Story. Toronto: CANAV Books, 1983. {{ISBN|0-07-549483-3}}.
- Rossiter, Sean. Otter & Twin Otter: The Universal Airplanes. Vancouver: Douglas & McIntyre, 1998. {{ISBN|1-55054-637-6}}.
External links
{{Commons}}
- {{Official website|1=https://www.vikingair.com/twin-otter-information/}}
{{de Havilland Canada}}
{{Viking Air}}
{{CF aircraft}}
{{Aircraft manufactured in Canada}}
{{US STOL and VTOL aircraft}}
{{Authority control}}
{{DEFAULTSORT:De Havilland Canada Dhc-6 Twin Otter}}
Category:1960s Canadian civil utility aircraft
Category:1960s Canadian military utility aircraft
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Category:Aircraft first flown in 1965