Thanks guys.
Bill, I wasnt sure if that was possible in FSX. Thought I would ask. Its for jungle landings, and I wanted some light debris of twigs and leaves to rustle up when the girl puts down. I didnt want the effect to show up though 'all' the time. I guess it could be switched on for 'dirt runways' (dust) only with a manual 'lock-out' for it so that you can land in the desert and not have flora chasing you. :d
Bill