Nissen then embarked on a civil career . In 1975 he became manager of the newly established company Offshore Helicopters , which merged with Helikopterservice already in 1977 . Nissen was then the chief executive officer of Fred . Olsen Airtransport from 1977 to 1981 . In 1981 he took over as chief executive officer of Widerøe . He remained here until 1988 . Nissen also served as president of Norsk Aero Klubb from 1982 to 1990 . During his time in Widerøe , a disastrous incident occurred . The Widerøe Flight 933 crashed near Gamvik , killing all fifteen on board . In 1988 Nissen himself declared that the crash as " unsolved " . In 2004 , Nissen still held this opinion , despite that two prior investigation commissions had announced conclusive answers . Another major part of Nissen 's period in Widerøe was the replacing of Twin Otter planes with Dash 7
Widerøe Flight 933
Widerøe Flight 933
Peter L. Nissen