Flight Incheon International Airport departs from Seoul Incheon International Airport at 08:45 and arrives at Qingdao Liuting Airport at 09:15.
The flighttime is about 1h 30m. The distance travelled ("as the bird flies"): 680 Km. So the average speed is roughly 453 Km.
There is an 1 hour time difference between Seoul and Qingdao