Flight Incheon International Airport departs from Seoul Incheon International Airport at 09:10 and arrives at Hanoi Noi Bai International Airport at 12:10.
The flighttime is about 5h 00m. The distance travelled ("as the bird flies"): 2409 Km. So the average speed is roughly 482 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 Tuesday, as prices are on average 732.5% higher than on Friday. (Average prices, based on 542268 datapoints.)
We have a lot more statistics for flights OZ 729 and between Seoul and Hanoi.