Someone, somewhere, is still pushing the idea of reopening the Lisburn-Antrim railway line and building a spur to the Airport. I remember looking into this a little, and discovering that the economics just aren’t there. It is my understanding that such a development would be expensive to construct, and not used enough to be sustainable. In short, the International Airport just isn’t big enough to justify it.
Translink is often criticised for being a bus heavy company, which is running down the rail system. Maybe, but on this one, aren’t they right?