Originally Posted by
ex-koelner
I'm facing the same challenge soon

Arriving on LH at 11:15am and looking at taking the KE flight to OKA at 2:35pm, which seems to be the last direct flight to Naha on that day. As the LH staff in Berlin often is rather clueless, I cannot count on them checking my luggage through to OKA. Therefore, I think I have to collect luggage, and flying in C might speed up luggage delivery. For the landside transfer from T1 to T2, is the shuttle bus the best, i.e. fastest way? Or should I look at the Airport Railroad too?
Based on the schedule, you will have around three hours to transfer from T1 to T2. In the case your luggage is not checked through, the transfer time should suffice, assuming no delay for the LH flight. Around your arrival time, there are SQ, MU flights that usually don't add much queue time for immigration clearance. Possibly you will take the shuttle bus at 12:15PM or 12:32PM (refer to this
Incheon Airport shuttle bus schedule and guide) so that you will arrive at T2 before 1PM. Since your next flight is at 2:35PM. this should be enough for check-in and getting to your KE boarding gate.
For landside transfer from T1 to T2, shuttle bus is the best free option. The fastest option is to take Incheon taxi, which will cost you around KRW 14,000.