Re:Rail Link
If you look closely at the EIA assessment documents,dated 18/04/16 from Planning 15/01697 it states the following regarding the Rail Link.
Provision of a new station located to the north of the existing rail lines (south of Stirling Place)
Elevated section of track to the north of the existing mainline railway of approx 450m including a bridge over the A1081
Section of TUNNEL (circa 200mtrs) to take the rail link under the existing airport approach lights at the end of the runway.
Track at grade or situated in cuttings running roughly parallel with the A1081 and across the mid term car park (850mtrs length )
A section of TUNNEL to take the rail link UNDER the taxiway and into the terminal building below ground level (roughly 700mtrs)
If you read the last sentence as into the CTA , they obviously think that the link was planned ( i say WAS, as it could easily change), to be underground.