I am relatively new at this whole scenery design business and 99.5% of what I do is for my personal use on my system to make an airport more closely match the real life counterpart. I use ADE9x and EZ-Scenery for almost all of my mods. As I understand it...and I'm probably very wrong in this assumption...the subject files are mostly for making default AI aircraft/default ATC react properly to the new conditions I create when modifying an airfield. I do most of my sim flying online on the VATSIM network with FSInn so the defaults are disabled anyway. I use charts to fly the departures and arrivals so I don't normally use the approaches found in the default aircrafts' GPS. I recently experienced a problem involving the Nav Display on my aircraft (default and freeware and payware) being off by as much as 15 degrees, however that topic is already being discussed in a different thread. One of the suggestions in that other thread was that I could have conflicting or corrupted AFCADs installed from the numerous addon sceneries I have installed. The process for finding that conflict/corruption is daunting to say the least. I'm tempted just to remove them all since, if they do what I think they do (control AI activity) I don't really need them. So, how important are they? Thanks Randy

Depends. Airport Facilities files (AFCADS or whatever you want to call them) have two functions. The first is to create the invisible functions of the airport and the second is the visual part. Functionally you are looking at the flow of aircraft around the airport. Visually you are looking at the taxiways, runways and aprons - sometimes these are hidden away underneath photo real or 3D aiports created using tools like GMax. Even so there will almost certainly be some underlying facilities file at work. Of course if you do turn off all AI traffic and do not use ATC then the hidden stuff becomes a bit less important. However if you are using ILS and other navaids then you are back looking at airport facilities. If these are in the wrong place then you will need some addon to correct them If you remove all the addon files then what you have left is the stock airports. I suspect that you will find some unexpected things happen. So I would rate them as important. To be honest there are several tools that can help you find duplicate airport facilities in different files. As a test you can remove them and see how everything looks. If none of the features you require are gone then fair enough you don't need them. Bear in mind that you will need to find them all to remove them so you are back at the point that you are trying to avoid I think. One of the messy things is not being able to find the different airport files that might have accumulated over time - especially if you have added third party packages

Thanks for the reply, Jon. The tools for finding duplicate facilities files sounds intriguing. I'll do some searches and see what I can find. Also, I didn't mean to imply I would remove the all the addon files, just looking at AFCAD/AF2 files right now. The scenery/textures for my addons will remain unless I find one that is the culprit. I disabled them in "addon scenery" and the degree deviation went away. Added them all back in one at a time and checked after each "re-enable" but never found a scenery that was causing the deviation so am now looking at the AFCADs. Randy

Jon, I found and downloaded a program called ScanAFD. After running the program I'm still not sure what I'm looking at, despite a pretty good readme file that explains the use of the program. After setting up the program to scan for duplicates in the default AFCAD directory, which I assume is Addon Scenery/Scenery in FS9, it found two airports, KORD and KSNA. In KORD it listed two .bgl files, AF2_KORD.bgl and KORD_ADE9_RVT.bgl (my mod of the default KORD to add runways). Both were enabled and their priority was 312, whatever that means. The program does not tell me what "conflicts" or is "duplicated" however. I kinda expected to find two files with the same name. The airport, KSNA, showed two files also, AFCAD2_KSNA.bgl and KSNA_John_Wayne_Santa_Ana_SNA2004_17pt359.bgl (wow, what a filename). Again, how do I know what is conflicting or being duplicated? If I include all addon sceneries in the search instead of just AFCAD Directory the list of airports becomes massive. Only in a few cases did it find two files with the same name, the airport in Sun Valley, Idaho, some Alaska sceneries, and Mexico. In all cases there was an AF2_XXXX.bgl in both the addon scenery folder and in Addon Scenery/Scenery, so I renamed the ones in AddonScenery/Scenery to .bak and restarted FS9. The 15 degree offset still exists. However, there are a bunch of airports that show up in the list and the files listed do not have the same name. Most are in the same overlying folder for the scenery. By example, I added some Icelandic airports that come as a group of .bgls for about 20-30 airports. For each airport there will be two files. AF2_ICAO Airport Name.bgl and AF2_Airport ICAO.bgl such as AF2_ Akureyi BIAR.bgl and also AF2_BIAR.bglwith the one with the spelled out airport name in Addon Scenery/scenery and the one with just the ICAO in Addon Scenery/Iceland/scenery. This was how the scenery install readme file said to do it. Still confused. Randy

Let's start by talking about duplicates. I don't use ScanAFD but I do have a tool of my own that does the job for FSX. However the principle is the same. The scanner will look for airports inside bgl files. It is not looking at file names. It looks inside the file for some code that relates to the Ident of the airport KORD for example. Duplicate is a bit of a misnomer. Frankly if you have the identical airport arrangement in two files it does not matter since they both generate the same visuals etc and so they are true duplicates. The problems arise when we find the airport code in two or more files and the content is different. So perhaps one has a taxiway in one place and one in another. When FS loads an airport it will load the code from all the files it can find. It starts with the stock airport. Then it goes through files in scenery priority order working up the order. For each set of airport code it loads it does two main things. Excludes from the code already loaded anything the new file tells it to exclude. Commonly runways, taxiways etc., and then loads its own. Sounds like a recipe for a dogs dinner? Yep it certainly can be. If the new file does not remove stuff in the previous files that it wants to change then you get stuff appear twice; if the designer set the exclude data poorly in the new file then stuff goes that should not etc etc. FS will carry on doing this until it reaches the last and highest priority. It is possible that it might load one two or many loads of airport code before it is done. Now to take a specific airport like KORD. You should never assume that the airport is loaded only in the addon scenery folder. Quite a number of addons will store AFCAD files in their own folders or in other parts of your setup. Traffic Addons can be seen to do this and cause problems. So the safest way is to scan for any files that contain the airport you are interested in. Then it is often a case of removing or disableing one at at time until your problem goes away. If the file with the problem in it has only that airport then you can just remove it. However if the file contains multiple airports then that is not an option. Finally as I mentioned earlier priority is king. The last file loaded gets to stamp on all the others so to speak. If your file is not top of the heap then some other file may be stamping on yours and undoing all the good work. You have two KORD files at the same priority. I would suggest removing the AF2 one and see if that helps.

Thanks for the insight, Jon, and one that makes complete sense as well... I looked at the scan program at your site and wish it worked for FS9 as well. ScanAFD was the only one I could find for FS9, my platform. I will keep plugging away. Thanks again, my friend. Randy