Flight Incheon International Airport departs from Seoul Incheon International Airport at 15:55 and arrives at Fukuoka Fukuoka Airport at 17:15.
The flighttime is about 1h 20m. The distance travelled ("as the bird flies"): 518 Km. So the average speed is roughly 388 Km.
The best day to arrive at Seoul is Thursday and it would be best to avoid Saturday, as prices are on average 375.39% higher than on Thursday. (Average prices, based on 680655 datapoints.)
We have a lot more statistics for flights LJ 265 and between Seoul and Fukuoka.
THB