Flight Da Nang International Airport departs from Da Nang Da Nang International Airport at 22:55 and arrives at Seoul Incheon International Airport at 05:30.
The flighttime is about 4h 35m. The distance travelled ("as the bird flies"): 2275 Km. So the average speed is roughly 496 Km.
There is an 2 hour time difference between Da Nang and Seoul
