You can dwonload some skyboxes here.
You can also use other sceneries for heli-x.
Or you can use a .scn file from one of my scneries.
http://www.szenerien.de/FMS-Szenerien/index.htm
You have to convert the jpg images into .BMP images
in order for FMS to use it.
There's 6 images in a skybox.
example....all the images are 2048x2048.
change the bottom image to 2050x2050
this will prevent the bottom image from gettting display.
The same thing will happened if you resize a model's color
scheme to an incorrect size...the model will turn white or
won't have texture.
For some reason the flashing is coming from the bottom
panel trying to get projected.
Bascially....a skybox is a model or an object.
If you go to rc-sim and download that ROOM 3D landscape.
resize the image "field" the an incorrect size. The ground will turn white.