The de Havilland Aircraft Company of Canada DHC-6 Twin Otter is a versatile, twin-engine turboprop aircraft designed for short take-off and landing (STOL) operations, capable of seating up to 20 passengers. Initially introduced in 1965, it was developed as a replacement for the single-engine DHC-3 Otter, maintaining its predecessor's impressive short-field capabilities. The aircraft is suitable for use on unimproved airstrips and can be configured with wheel, ski, float, or amphibious float landing gear.
The DHC-6 was produced in several variants, including the Series 100, 200, and 300. The Series 100 was the first production model, followed by the Series 200 in 1968, which featured an extended nose and larger baggage capacity. The Series 300, introduced in 1969, became the most successful model, equipped with more powerful engines and improved performance. A total of 844 DHC-6 Twin Otters were built before production ended in 1988.
The aircraft has been widely used across the globe, from the Arctic to Antarctica, by both civil and military operators. Significant fleets were operated in countries including Norway, the Maldives, the United States, Canada, Mexico, and Australia. Notably, it is also used by the British Antarctic Survey and the United States Antarctic Program.
After de Havilland ceased production in Canada, Viking Air acquired the aircraft's type certificate in 2006. Viking began producing a new variant, the Series 400, with more powerful engines. The first Series 400 aircraft was delivered in 2010, and by 2017, over 125 units had been produced. The DHC-6 remains in service worldwide, with its current operators using the aircraft in regional aviation, military missions, industrial support, and private air charter.