Flyers choose Korean Air for its offering of comfortable first class seats, which make air travel easier. Moreover, Korean Air First Class flies on various routes, but a few are the most frequent based on locations. Seoul (SEL) to New York (JFK), Jeju (CJU) to London (LHR), and Singapore (SINA) to San Francisco (SFO) are more frequent and are picked by most of the passengers to save time finding other routes. To know more about it, visit the Korean Air official website or read the aforementioned blog link by FaresFirstClass.