Do not use the Lot 20 F/A-18 for static... use the other F/A-18 static object. I don't have my computer in front of me right now, but IIRC there are two. - "F/A-18 Lot 20" and "F/A-18" or something to that effect. Using the latter helps FPS a LOOOOT and you really don't loose much as you'd have to be right up on them to see the difference.
Unless something has changed, in which case, disregard everything I've said here.