Flight Gimhae International Airport departs from Busan Gimhae International Airport at 20:50 and arrives at Da Nang Da Nang International Airport at 00:05.
The flighttime is about 5h 15m. The distance travelled ("as the bird flies"): 2495 Km. So the average speed is roughly 475 Km.
There is an 2 hour time difference between Busan and Da Nang