Flight Incheon International Airport departs from Seoul Incheon International Airport at 22:55 and arrives at Qingdao Liuting Airport at 23:40. The flighttime is about 1h 45m. The distance travelled ("as the bird flies"): 680 Km. So the average speed is roughly 389 Km. There is an 1 hour time difference between Seoul and Qingdao
