Do a search for a piece of software called "BAO Tower" or even just "Tower".
As far as I'm aware it's classified as abandonware now and thusly is available on some sites legally available for download.
It's a Windows 3.1 based Tower (aerodrome) sim that's a reasonably entertaining and passable bit of software. It is, as these things tend to be, US based but it's still good fun nonetheless.
Hope this helps
