Flight Incheon International Airport departs from Seoul Incheon International Airport at 11:05 and arrives at Osaka Kansai International Airport at 12:55.
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 Seoul is Saturday and it would be best to avoid Friday, as prices are on average 246.1% higher than on Saturday. (Average prices, based on 2256851 datapoints.)
We have a lot more statistics for flights JL 5270 and between Seoul and Osaka.
