Pan American World Airways
United Airlines, then the dominant carrier at PDX, used Portland as a once-weekly stop for its Chicago–O'Hare-Tokyo–Narita service from 1983 to 1987. The flight stopped in Seattle/Tacoma six days a week and in Portland once a week. After United Airlines acquired Pan American World Airways' Asian routes in 1986, they were able to use Pan American World Airways' Boeing 747SP aircraft to eliminate the West Coast stop.