Modifying: AIR vs. CFG vs. MDL files

Hey everyone,

So quick question about modifying/tweaking the performance of airplanes: Basically, which file (.air, .cfg, .mdl) has what effects on the flight of the airplane?

For example, I have the newest Project Airbus A319 (v2.2) and found it to fly much better than the previous version. However, it doesn't seem that the 320 and 321 have been updated. Would copy/pasting the .air file of the 319 into my 320 models (and modding the .cfg to read as such) allow the 320 to fly like the 319, or is it not that simple? 

Thanks!

Nick