Flight Incheon International Airport departs from Seoul Incheon International Airport at 11:15 and arrives at Guangzhou Guangzhou Baiyun International Airport at 14:00.
The flighttime is about 3h 45m. The distance travelled ("as the bird flies"): 1648 Km. So the average speed is roughly 439 Km.
There is an 1 hour time difference between Seoul and Guangzhou
THB
