[FZ]

You only need to modify line Class air.FW_190A4 in each .mis file of your campaign and make it Class air.FW_190A3, you can also change the skins ..., and skill level, weapons etc ....

Just open your Missions folder, then Campaign, then DE, then name of the campaign you want to fly ... (open with Notepad for ex)

You've got a whole bunch of campaigns here:

http://mission4today.com/index.php?name=Downloads&c=2