The Zeppelin NT is certified for single pilot operation, in this case the other seat is taken by the stewardess (since there is no meal service she acts more like a tour guide). The airship is certified to be flown under visual flight rules during night and day time.
If anyone is interested- the company offers pilot training, applicants require a Commercial Pilot Licence with at least 1000 flight hours. Training consists of 93 hours theory and approx. 50 flight lessons. After the test applicants must log 150 flight hours under supervision. BEWARE: The market is pretty limited right now- just 26 people worldwide have a rating for this