Flight Haneda Airport departs from Tokyo Haneda Airport at 02:10 and arrives at Seoul Incheon International Airport at 04:40.
The flighttime is about 2h 30m. The distance travelled ("as the bird flies"): 1487 Km. So the average speed is roughly 595 Km.
The best day to arrive at Tokyo is Sunday and it would be best to avoid Friday, as prices are on average 121.09% higher than on Sunday. (Average prices, based on 1325439 datapoints.)
We have a lot more statistics for flights MM 809 and between Tokyo and Seoul.
NZD
