The airports have queue systems so planes don't run over each other on the runway (there are bugs I have to iron out) and wait for their turn to get to the 3 loading areas. The planes also wait for their to turn to get out of the loading areas and on to the runway.
The plane banking when turning is done by comparing the rotation of the plane between two frames and blending in animations stored in the mesh, so there is a bug when turning from 179° to -179°.