Flight Incheon International Airport departs from Seoul Incheon International Airport at 12:45 and arrives at Tianjin Tianjin Binhai International Airport at 13:35.
The flighttime is about 1h 50m. The distance travelled ("as the bird flies"): 1017 Km. So the average speed is roughly 555 Km.
There is an 1 hour time difference between Seoul and Tianjin