Originally Posted by
Crocodile
The North Satellite Concourse is accessed via a shuttle that leaves every few minutes (bus).
The gates on 4F (511-513, 521-524) are used to access the planes parked away from the gates, via bus directly to the plane. So, yes, they are shuttle gates.
HKIA Map
I hope they plan to build a tunnel between the satellite gates and the main terminal.