Huh? I always thought jeans was not business casual. I always wear khakis and a collared shirt when jumpseating, even if I know I'm going to get a seat in back. So whenever I non-rev, I always throw in a pair of nice pants into my roller bag, just in case. In fact when I got back from Europe yesterday, I slipped into my khakis so I could jumpseat on another airline to get the rest of the way home.