Flight Incheon International Airport departs from Seoul Incheon International Airport at 17:40 and arrives at Tokyo Narita International Airport at 20:05.
The flighttime is about 2h 25m. The distance travelled ("as the bird flies"): 1555 Km. So the average speed is roughly 643 Km.
The best day to arrive at Seoul is Sunday and it would be best to avoid Wednesday, as prices are on average 230.48% higher than on Sunday. (Average prices, based on 5579335 datapoints.)
We have a lot more statistics for flights ET 672 and between Seoul and Tokyo.
NZD
