In the 1960's production of the de Havilland single-engined Otter was declining and a market for twin-engined Short Takeoff and Landing (STOL) aircraft with US commuter airlines was emerging. The DHC-6 Twin Otter was a redesign of the DHC-3 Otter incorporating twin PT6 wing mounted turboprop engines, extended wings and a stretched fuselage. The prototype flew in 1965. It's double-sided trailing edge flaps and airelons vould be dropped to give the aircrf=ft remarkable Short Takeoff and Landing (STOL) capabilities. The aircraft could accomodate 12 to 18 passengers.
The Twin Otter can serve equally well as a rugged bushplane or as a commuter liner. Its fixed wheel landing gear can be equipped with skis and the aircraft can be fitted with floats for water operation.
884 Twin Otters were produced before production ended in 1988. It was sold world-wide in in over 70 countries.