[somt1033]

Ok,
I don't want to bother you with noob questions, so i did some more research and i think i figured out how to do it, but i haven't tried it yet.

So here is what i think might work:

1.Convert cad file to .obj8 file with ac3d.

2.Create textures for it using Photoshop/ac3d

3.create new aircraft folder in ...xplane\aircraft
copy some already existing aircraft with all files and sub folders into this new
directory.

4. open the texture files of the already existing x-plane aircraft in photoshop or something compareable
and delete them and save them.

5.copy the .obj8 file of the cad model together with it's textures into the ...newaircraft\objetcs
folder of the new aircraft.

6. start planemaker. Now, the old aircraft should be invisible because we deleted
the textures. Under misc objects import the cad aircraft model with lat lon
equal zero.

This should work i hope. I will try tomorrow.
The Flight dynmaics will be that of the original aircraft which was made invisible.
But this is no problem for me, because i only use X-plane for visualiation.
The flight dynamics are simulated by Matlab/Simulink which is interfaced to x-plane via UDP.

Fell free to comment on what i suggested here!
Help is welcome!
Greetings,
Marvin