Flight Incheon International Airport departs from Seoul Incheon International Airport at 18:45 and arrives at Hanoi Noi Bai International Airport at 21:35.
The flighttime is about 4h 50m. The distance travelled ("as the bird flies"): 2409 Km. So the average speed is roughly 498 Km.
There is an 2 hour time difference between Seoul and Hanoi
The best day to arrive at Seoul is Friday and it would be best to avoid Monday, as prices are on average 1263.22% higher than on Friday. (Average prices, based on 526902 datapoints.)
We have a lot more statistics for flights KE 455 and between Seoul and Hanoi.