Add-on aircraft textures missing or scenery flickering

So I have an interesting problem here. If I turn on DX10 then the aircraft I have that don't support it all have missing textures. But if I go back to DX9 to fix this issue, another issue arises where it seems like the ground textures flicker across my whole screen when I move the camera around in an external view, like the ground texture flickers vertically, it's really strange. If I go back to DX10 this flickering issue disappears entirely but then I can't use a lot of my aircraft. Does anyone have any idea how to fix this flickering