I once asked the purser of an aeroplane I was P2 on what the girls kept in their "hostie bags". She showed me some running shorts and told me that if they had to use the slide they had been told that nylon tights could be burnt into the flesh by the friction on the slide.
I have no idea if its true, but when I'm a passenger I keep a close eye on the girls, if they appear to be hitching things up under their skirts, then we may be using the slides shortly
Then again, tights are the work of Satan, maybe stockings and no underwear is the answer