IIRC someone over here at BioHaz said this before so this is their idea NOT mine. All credit goes to the original poster.
You place this in the note of the AI airplanes, in (AircraftData)
CockpitDataFile=A-4E_COCKPIT.INI
HangarScreen=
LoadoutImage=
AvionicsDLL=Avionics60.dll
AvionicsDataFilename=F-4E_avionics.ini
For example, the Mig-21PFM, will be this way:
[AircraftData]
AircraftFullName=MiG-21PFM Fishbed-F
AircraftDataFile=MiG-21PFM_data.ini
LoadoutFile=MiG-21PFM_loadout.ini
CockpitDataFile=A-4E_COCKPIT.INI
HangarScreen=
LoadoutImage=
AvionicsDLL=Avionics60.dll
AvionicsDataFilename=F-4E_avionics.ini
There you go! This should significantly reduce the number of posts saying "how do I make this flyable?"
You can also d/l a document of this for your own records.
How_to_make_AI_Planes_Flyable.rtf