Hi everyone,
I created a fictional airport with ILS. Everything works fine. I have the default ai planes landing and taking off. My only snag is the ILS approach. I'm sure this question has been answered but I can't seem to find it. All of my runways show up as visual runways and not ILS runways. Can anyone point me in the right direction? Thanks.

Did you add the approach code for the ILS?

Yes.  Approaches are the code that is needed to tell aircraft where to fly.  Planes will land if you add an ILS but don't add any approach code.  However if you want it to show up in the GPS and so on you need to add some approach code.  A simple ILS approach needs two fixed points Initial Approach Fix (IAF) and Final Approach Fix (FAF).  These are placed IAF about 10 miles from the runway on the runway line and FAF about 3 miles out.  The approach consists of three 'legs'  First based on the IAF, second based on FAF and third based on the runway.  Finally you would want a missed approach leg to get the plane away if it called missed approach.  Of course if you are working on an airport that has published approach plates then the approach code in FSX should match that.

There is a tool on at least one of the download sites that makes coding approaches a bit easier. 

Most people write their approach code by hand and it is not forthe faint hearted.    First stop is the BglComp SDK that does explain the code.  I am actually working on this stuff at the moment