Flight Da Nang International Airport departs from Da Nang Da Nang International Airport at 01:30 and arrives at Seoul Incheon International Airport at 08:15.
The flighttime is about 4h 45m. The distance travelled ("as the bird flies"): 2275 Km. So the average speed is roughly 479 Km.
There is an 2 hour time difference between Da Nang and Seoul
