This is from SeaTac's newsletter;
Just in time for the busy vacation travel months, four airlines - Asiana Airlines, British Airways, Horizon Air, and Korean Air - are adding summer flights this year. A new airline for Sea-Tac AirTran Airways begins seasonal service in late May. Korean Air will also be adding a permanent Sunday flight to Seoul to its existing three-day-a-week schedule.
Air Tran Airways begins summer Seattle-Atlanta nonstop service on May 25. The two daily flights will run through Labor Day.
Asiana Airlines will offer a new Friday flight to Seoul from July 21 to October 13.
British Airways will add a Monday, Wednesday and Saturday London flight from June 3 to October 9.
Horizon Air will offer flights between its Seattle hub and the Oregon Coast for the first time when it begins daily service to North Bend/Coos Bay on June 25. The summer flights will end on September 9.
Korean Air is adding both a summer and year-round flight to its current Tuesday, Thursday and Saturday schedule to Seoul . Its summer flight will operate on Mondays from March 27 through August 27 and in August Korean will inaugurate a Sunday Seattle-Seoul flight that will be offered throughout the year.