Flight Kansai International Airport departs from Osaka Kansai International Airport at 18:20 and arrives at Seoul Incheon International Airport at 20:10.
The flighttime is about 1h 50m. The distance travelled ("as the bird flies"): 1002 Km. So the average speed is roughly 547 Km.
The best day to arrive at Osaka is Friday and it would be best to avoid Sunday, as prices are on average 427.56% higher than on Friday. (Average prices, based on 6331853 datapoints.)
We have a lot more statistics for flights JL 5215 and between Osaka and Seoul.
