Some people say, the Zeppelin NT is a lighter-than-air aircraft. That is why the German, Swiss and Austrain people say "fahren". This is not quite correct. The Zeppelin NT takes off with a static weight of approx. 350 kg. Therefore, it is heavier than air and that means the Zeppelin is flying, in German language "fliegen".
A hot-air balloon is a lighter-than-air aircraft. The Zeppelin NT climbs using its three engines, whereas a balloon climbs solely by means of helium or hot air.