Simviation Forums

air files contain the info for how the plane flys.
the cfg files do somthing... I have no idea actually... damn...
the dp file contains all the weapons info for that plane. you can edit it to give your plane more guns, rockets, bombs etc.
the cdp file is related to the dp file in some tedious way. it needs to be deleted for changes in the dp file to work. the cdp file is automatically remade when you start CFS2.

The DP file will also list damage profiles for your acft., specified in the "Box Strings". The DP file also will list any FX your acft. should display, when and how much and under what conditions.
The CFG file also has flight characteristics and norms for the acft. Plus many other things. It is closely tied to the air file.
For your benefit, being new, don't mess with any of them for now. Changing anything in the air or dp files of your STOCK acft. makes them MODS which raises hair on the back of most pilots on the Zone. :-)