The programs available depend on your version of FS. I will list some freeware programs compatible with FS2004.
FlattEx-generates the code to flatten the area (required for runways, etc. to display properly) and exclude (remove) unwanted autogen and scenery objects.
Afcad 2.21-creates the airport facility so it is available in the FS airport list and visible in GPS and map. Creates the visible runways, taxiway, etc. Creates comm freqs. and nav freqs. and aids. It does not place scenery objects.
Rwy12 v1.2 Object Placer-Place buildings and other scenery objects to complete your airport and surrounding scenery. (5 download files: the program, 3 object libraries, and 1 document)
Except for Afcad, there are other programs available that do each of these tasks equally well. Noteably, Abacus EZ-Scenery (payware) allows you to place objects from within the FS flight screen. But, for your first project, these will do the job with a minimal learning curve.
Each of these programs requires a module to connect to FS for position. Read the documentation for each to determine what
At that time [1909] the chief engineer was almost always the chief test pilot as well. That had the fortunate result of eliminating poor engineering early in aviation.