Flight Incheon International Airport departs from Seoul Incheon International Airport at 17:30 and arrives at Dalian Zhoushuizi Airport at 17:40.
The flighttime is about 1h 10m. The distance travelled ("as the bird flies"): 554 Km. So the average speed is roughly 475 Km.
There is an 1 hour time difference between Seoul and Dalian