I think there is only one way to get rid of them that I have heard. I have not tried this my self. But I beleive the program only reads the names of the aircraft folders. Perhaps you can delete the content of the stock planes folder and insert or copy and paste the information from whatever WW1 plane you like into them. Maybe this will solve your problem . Its not perfect but its better than having to see does Pacific planes when you really want to see WW1 planes in  that CFS2 install. If this method works please let us know. Thank you James007