The fixed-gear, twin-engine Twin Otter first flew in 1965. The Pratt & Whitney PT6A-20 powered early version and the DHC-6-300 Twin Otter is powered by the more powerful PT6A-27 engine. The Twin Otter ended production in 1988.
The Twin Otter was designed as a utility aircraft. With fixed-gear, the aircraft can be transferred from wheels to floats or skis. In addition to passenger and cargo operations, Twin Otters are in use in roles such as air ambulance and maritime surveillance. The aircraft is known to be reliable and dependable and is in use in many remote areas of the world.
In 2007, Viking Air of Canada purchased the type certificate and production rights to this and other out-of-production DHC aircraft.