Scenery Static aircraft

Hi All, I have a question for fs2003....how do I delete static aircraft out of some add on scenery ? I have alot of add on AI Aircraft that are flying to airline scheduals and all these static aircraft in some scenery is killing my frame rate is there a easy way of deleting the static aircraft .Also Im running a P4 2.6 PC with 768 DDR and have a G4 4200TI GFX card with 128ddr onboard and still my frame rate sucks when im flying out of some add on scenery airports can one offer some ideas ?? thanks for your time .V-S