Services were at first operated by Scandinavian Airlines System (SAS). At the beginning the airline used 56-passenger Convair CV-440 Metropolitan aircraft, which flew flights south to Oslo and westward to Lakselv and Kirkenes—and also to Tromsø starting in 1964. The general route scheme of flying multi-legged flights from Oslo to Finnmark remained until 1990. On 7 April 1969, SAS introduced the 85-passenger Douglas DC-9-21 jetliner on the Alta service; the last Metropolitan flew on 1 April 1970. Five regional airports opened on 1 August 1974, Sørkjosen, Hammerfest, Mehamn, Berlevåg and Vadsø, all which were connected to Alta and other primary airports by Widerøe using de Havilland Canada DHC-6 Twin Otters. Honningsvåg Airport opened on 1 July 1977. SAS' traffic increased throughout the 1970s, resulting in SAS gradually increasing the frequency of its services, and later also using larger DC-9s. The McDonnell Douglas MD-80 was first flown on the Alta route on 11 July 1986.