 In the beginning of the 1970s , Alaska Airlines began charter service to Siberia in the Soviet Union . This was the result of three years of secret negotiations between Alaska Airlines and Soviet authorities , in which the US Department of State reluctantly chose not to block the plan for fear of a potentially negative response from the Soviets . The airline gained permission to fly more than two @-@ dozen flights in 1970 , 1971 and 1972 . Alaska Airlines was also operating Boeing 707 , Boeing 720 and Boeing 720B jetliners during the early and mid 1970s . 
