All FS9 models made to the FS9 SDKs are compatible with FSX.

THe problem is that it may not be as easy to just copy the aircraft folder into the Simobjects/Airplanes folder that FSX has. IF the model has all the sounds, panels and gauges in its own container, then there should be no problem.

What I have done is create a new “Aircraft” folder under the main FSX folder, and then add a line to the [MAIN] section of the FSX.cfg file to read:

[Main]
User Objects=Airplane, Helicopter
SimObjectPaths.0=SimObjectsAirplanes
SimObjectPaths.1=SimObjectsRotorcraft
SimObjectPaths.2=SimObjectsGroundVehicles
SimObjectPaths.3=SimObjectsBoats
SimObjectPaths.4=SimObjectsAnimals
SimObjectPaths.5=SimObjectsMisc
SimObjectPaths.6=Aircraft <—– this line added

THen I install the model “normally”.