Do you need to know this sort of thing for UAS interviews or only for the actual OASC interviews?
Having that knowledge will not be a hinderance, but don't be surprised if it's not deeply explored at interview. The formal interview for UAS selection is broadly comparable with that of the OASC interview, but UAS' are always open to those with little to no prior knowledge of the RAF or flying, so if you know it, great, extra brownie points.
Incidentally, which UAS would you be hopefully applying for?
You might also want to go to
http://www.thestudentroom.co.uk and look in the Armed Forces forum where there is an UAS thread.