(SN 845) made its first flight on 16 February 2010, in Calgary, Alberta. 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. In June 2017, 125 have been made since restarting production in 2010. Variants Twin-engine STOL utility transport aircraft, powered by two Pratt & Whitney PT6A-20 turboprop engines. DHC-6 Series 110 Variant of the Series 100 built to conform to BCAR (British Civil Air Regulations). Improved version. Twin-engine STOL utility transport aircraft, powered by two (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. 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. 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 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. lighter than the 400. 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 It has been replaced by the Short C-23 Sherpa in United States Army service.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. 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 UV-18s in its inventory as free-fall parachuting training aircraft, 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