KE 852 then LJ 27 at Incheon
Beijing Capital → Seoul → Chiang Mai
Timetable, Seoul time
21:55KE 852 from Beijing Capital at the gate
16:45LJ 27 to Chiang Mai leaves the gate
18 h 50 apart on the timetable, overnight
LJ 27 leaves 18 h 50 after KE 852 arrives on the timetable: more than half a day, so not a connection we count.