AT crews are almost always co-located, for obvious reasons. Which 'mess' were the rooms in? You may be shocked to realise, as a fast-jet mate, that we have (gasp, horror!) NCO Aircrew as well (and JR stewards on the shiney fleet). In which case, 10 rooms in the 'Os' mess wouldn't cut it - or even 100 rooms - if there is no space in the SNCOs / JRs accomodation.