I'm not sure if you've had a look at page 61 of the manual. Also, what kind of jetways does this particular scenery have. It's possible that the jetways may be in one of the files in the airport's scenery folder. If so, you may try moving that file out of the scenery folder and see if that solves your issue. If, on the other hand, it's tied into the terminal, you might be out of luck.