Flight Haneda Airport departs from Tokyo Haneda Airport at 01:30 and arrives at Seoul Incheon International Airport at 04:10.
The flighttime is about 2h 40m. The distance travelled ("as the bird flies"): 1487 Km. So the average speed is roughly 558 Km.
The best month to arrive at Tokyo is February and the most expensive month to fly is June. (Average prices, based on 1424 datapoints.)
The best day to arrive at Tokyo is Friday and it would be best to avoid Thursday, as prices are on average 18.3% higher than on Friday. (Average prices, based on 1271897 datapoints.)
We have a lot more statistics for flights GA 177 and between Tokyo and Seoul.
THB
