I flew into ICN yesterday early evening and noticed that KE was using all the gates on their half of the main terminal, half of the OZ pier, and two gates at the concourse terminal had KE planes parked at them. When I departed ICN about the same time last week, I noticed then a KE plane also at the concourse terminal. Is KE now so maxed out at the main terminal that they now need to sometimes use the concourse terminal? That time of the evening is not normal for me to arrive or depart, so maybe it's always been like this and I just never saw it. Definitely later in the evening I've never seen all the normal KE gates, plus some being used.

KE occasionally uses concourse, but only for arriving flights. On a usual days, even without any weather disruption, 5 to 10 KE flights arrive on the concourse A between 4-6PM.

Thanks for that information. I guess because I almost never use ICN during those hours, except for last week, was why I first noticed it. Makes sense to do it that way, being there's little disruption to the passengers if they only arrive at the concourse terminal, but can depart from the main terminal, where the regular KE lounges are, etc.

I seem to recall seeing Jin Air planes at both terminals in the past. Guess that's probably the same deal as with KE planes.

Sounds like they're reaching some capacity problems to some degree. Do you or anyone know what's the status of the Phase 3 expansion of ICN? I read that they will build another terminal, I'm assuming which will be a real new terminal with separate check-in, immigration, etc, and supposedly will come online by around 2017. Are they still on schedule? Wonder how they'll divide up the airlines between the terminals. If KE is already needing to use the concourse terminal, sounds like they'll be able to fully utilize the main terminal all by themselves, with perhaps Jin Air and/or Jeju air or some other small Korean carriers there. Maybe move OZ to the concourse terminal and have it dedicated for them, plus perhaps Star Alliance, and the new terminal for all others. Or Asiana at the new terminal, and keep the foreign airlines at the concourse. But I've seen on occasion foreign airlines using the main terminal, at least for arriving aircraft, so even the concourse terminal is I think reaching capacity at times. Especially with the boom in expansion of routes between Korea and China. I don't see OZ and KE both remaining at the main terminal being an option.

Personally I'd like to see them go to a true 24-hour airport, with increased limousine bus services throughout the night. Seems there's already some movement towards that, with SQ as well as some others now having departures after midnight. But without having better public transportation during the off-hours, passengers currently are left with needing to use an expensive taxi to get to/from the airport, except for some very limited and infrequent night routes that currently exist.

Right now ICN is a great and convenient airport. I just hope that whatever they do to handle the inevitable increase in traffic doesn't make it less of the great airport it is.

To answer my own question, I googled it and found this:

http://nanoomi.net/archives/13807

Says that OZ has agreed to move to the new terminal, leaving the existing terminal all for KE. Guess that means a brand new OZ F lounge for me to try when it opens up. Looks to be way bigger than what OZ needs, so I imagine they'll at least move the Star Alliance carriers to the new terminal. That could be good in some ways (easy connections), but bad in others (lots of *A passengers sharing the same lounge with OZ passengers). Wonder if KE will take over the old OZ lounges and have more capacity. Well, still 4 or 5 years down the road, so no need think too much about it all for right now.

On a side note, when I flew in yesterday, I got a good view of the Mag-lev train under construction. Seems to be coming along well. I think it's scheduled to open up the first section later this year.

The airport's current capacity is 44M/year, and total passenger number was 35M in 2011, and it will be like 38M in 2012. By 2017, when the third phase opens, the capacity will go up to 62M. Although the passenger number is quickly reaching the capacity (44M), this airport is busy only on certain peak times, and runway usage is well below 60% of available slots. (So no additional runway on the 3rd stage)

KE's concourse arrivals are more or less due to not efficient use of gates (wrong airline distribution), and not due to lack of capacity. Since both KE and OZ use the same terminal, and since both airlines have same peak hours, main terminal becomes crazy on those times. If they were mixed with foreign airlines, which has different peak times (or no peak hours at all), the problem would have been solved.

By the way, I don't think they decided which airlines (or alliances) will used the new terminal. Both KE and OZ wants to go there, and it's still undecided, despite of your source. Either KE+skyteam or OZ+star will move to there, and the other alliance will leave (or move) on the main terminal. Since KE+skyteam is larger at ICN, I expect the new terminal will be skyteam's. The others (and oneworld) might use concourse A.

To me, it seems they make very inefficient use of their existing runways. I normally depart ICN between 20:00 and 21:30. There's very frequently a significant backup of planes waiting to depart during that time, and sometimes our plane will wait 30 minutes or more at the gate waiting for a departure slot. But the third runway, AFAIK, is just idle during that time. I don't know anything about runway operations or the specifics at ICN, but seems to me they really need that third runway operating during that time period.

I think for departures, KE and OZ have their peak departure times in the evening, though in the early morning there's another peak. For arrivals though, I think it peaks in the early morning for all airlines, KE, OZ, and foreign, because there's a huge number of red-eyes that arrive at that time. There's no public transportation before roughly 05:00, so all the airlines want to arrive between 05:00 and 07:00. It's been during that time when actually I arrived at a main terminal gate on one of my TG flights, I'm assuming because all the gates at the concourse were occupied. So while the capacity has not yet been reached overall, I think it already has been reached during these peak times we're talking about. Still though, the airport operates extremely efficiently even at peak capacity. Outbound waits are never too long at security/immigration, and there never seems to be any problems at check-in that I can see. The OZ business class lounge can get overcrowded from what I've seen, but I don't know about the KE lounges.

If I'm reading the map of the airport expansion right, the new terminal will be built in two different phases, with half of it completed in Phase 3 and the remainder in Phase 4. If that's the case, I don't know that half of the terminal would be big enough for KE, but it certainly would be big enough for OZ.