2. AFCAD is not an add-on for FS2004. It is a program that you use to modify existing airport BGL files in FS2004, or create new airports. It contains the "invisible" data that FS2004's ATC needs to park, launch, and receive aircraft. The display on your screen is a non-valued-layer display. It will appear in your scenery if there are no valued-layer textures/terrain to override the AFCAD presentation.
3. You cannot overlay a background photo or drawing onto the AFCAD screen; it doesn't have that capability. If you are modifying or creating an airport, you will need other resources in other screens if you plan to use any kind of "guide" to help you layout the airport.
4. You cannot add scenery objects in AFCAD; it doesn't have that capability.
5. Since AFCAD uses the processes in the bglcomp_SDK, it is more than likely that any airport modifications you make, or any new airports you make, using AFCAD v2.21 will be compatible with FS X as well as FS9.
6. Lee spent a lot of time assembling a tutorial for AFCAD. You can access it by opening AFCAD, clicking on HELP on the top toolbar, then selecting Help from the menu that pops up. Go through that tutorial first -- before asking "How Do I ...." questions and DEFINITELY before attempting to modify or create an airport.
Lee has dropped off the radar; he used to issue updates at regular intervals, but no one has seen/heard from him since spring 2005. In all likelihood, he is no longer involved in MSFS products. He has made no appearances in forums he used to participate in and has not responded to emails in over a year.
If you don't find answers to your questions in the tutorial, or the instructions don't make any sense to you, by all means post your question in this topic area. There is enough AFCAD expertise among FS2004.com members that I'm sure we'll be able to help you and get your project moving again.
Edit, 13 April 2007: You might also find THIS FILE useful; it's a hints & tips document (.doc and .pdf format) by David "Opa" Marshall. Whether a beginner or an old AFCAD hand, Dave has probably got something in there you'll find of some value. (file originally discovered by mobisone)
Edited by sarge, 21 May 2011 - 09:29 AM.