The de Havilland Canada DHC-6 Twin Otter, currently marketed as the Viking Air DHC-6 Twin Otter, is a Canadian 19-passenger STOL (Short Takeoff and Landing) utility Aircraft .
Design and development ..
Development of the aircraft began in 1964, with the first flight on May 20, 1965. A twin-engine replacement for the single-engine DHC-3 Otter retaining DHC's renowned 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 550 shp (410 kW) Pratt & Whitney Canada PT6A-20 turboprop in the early 1960s made the concept of a twin more feasible. A DHC-3 Otter with its piston engine replaced with two PT6A-4 engines had already flown in 1963. It had been extensively modified for STOL research.To bush 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.
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 550-shaft-horsepower 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 680 hp (510 kW) engine that was flat-rated to 620 hp (460 kW) 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,[5] In 1976, a new -300 would have cost $700,000 ($3 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.
New production ..
After Series 300 production ended, the remaining tooling was purchased by Viking Air of Victoria, British Columbia, which manufactures replacement parts for all of the out-of-production de Havilland Canada aircraft. On February 24, 2006, Viking purchased the type certificates from Bombardier Aerospace for all the out-of-production de Havilland Canada aircraft (DHC-1 through DHC-7).The ownership of the certificates gives Viking the exclusive right to manufacture new aircraft.
On July 17, 2006, at the Farnborough Air Show, Viking Air announced its intention to offer a Series 400 Twin Otter. On April 2, 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.As of November 2007, 40 firm orders and 10 options had been taken and a new final assembly plant was established in Calgary, Alberta.Zimex Aviation of Switzerland received the first new production aircraft, serial number 845, in July 2010.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.On June 17, 2015, Viking further announced a partnership with a Chinese firm, Reignwood Aviation Group. The group will purchase 50 aircraft and become the exclusive representatives for new Series 400 Twin Otters in China.
Major changes introduced with the Series 400 include Honeywell Primus Apex fully integrated avionics, deletion of the AC electrical system, deletion of the beta backup system, modernization of the electrical and lighting systems, and use of composites for nonload-bearing structures such as doors.
The 100th Series 400 Twin Otter (MSN 944) was displayed at the July 2017 EAA AirVenture Oshkosh. Currently, 38% are operated as regional airliners, 31% in military aviation or special missions, 26% in industrial support and 5% in private air charter. Additionally, 70 are on regular landing gear wheels, 18 are configured as straight or amphibious floatplanes, 10 have tundra tires and 2 have wheel skis.
In 2019, Viking started making plastic components for the Twin Otter by 3D printer to help reduce cost.In 2021, its equipped price was $6.5M ..
16 сен 2024
