Performance problem on "open" airfields.

[bald_eagle]

Hi.

The problem is only on airfield without specific runway, but a grass or dirt open field. Like most of the airfield on the Moscow map.
This happen both in SP and in MP. The problem is not only when I am landing or taking off but also when flying over the field below 600 meters.

If I fly around the filed (close by ) and look at it there is no problem.

If I fly over it but look somewhere else there is a problem.

 

Does anybody else suffer from this?

 

Thanks. 

[bald_eagle]

It was the "Distance grass" option in the Graphic settings.