Hmmm. So do I put both the 4.10 version files and the FM_4.09 folder in my MODS folder? Or is the FM_4.09 placed somewhere inside the 4.10 version folder? This installation is different than most 4.09 aircraft...
If you have a 4.10 install or a DBW, then simply download the files for the 4.10 installation. Forget about 4.09 completely.
Unzip the downloaded 4.10 for PZL24 zip into either your MODS folder or your #DBW folder depending upon which game install you have.
Then add the following lines to your air.ini file:
P_24a air.P_24A 1 pl01 SUMMER
P_24b air.P_24B 2 g01 SUMMER
P_24e air.P_24E 2 g01 SUMMER
P_24f air.P_24F 1 pl01 SUMMER
P_24g air.P_24G 1 pl01 SUMMER
That is all there is to the install. The first times may be a bit daunting, but after several new plane installs, you'll see they all work in the same manner.
If you have DBW, you will already have the diff_FM mod, if you have a 4.10 install, check to see that it is installed.