Originally Posted by
stargold
I don't recall seeing an airside transit path upon arrival at GMP (admittedly I am always exiting at GMP so I didn't look very hard) so there may not be a way to stay airside.
There are often very, very long queues for entry immigration for non-Koreans so I would think twice before risking a 1hr connection at GMP, unless there is clarity that an airside transit is possible.
I don't recall seeing a connection sign either.
Apart from the entry wait time, exit passport control and security can be sluggish as well. I would say a back-to-back is impossible without an airside connection.