This exactly. Some Airships R/C scale 1/4 have something about 10 meters of size. Nothing badly if to consider that some with full power reach 30 Km/h. There are two types of airships: indoors and outdoors. Indoors is for flights only in inwards, or either, gymnasia, plants, etc. Outdoors is for flights in opened spaces, but with calm wind and without turbulence, or either, sky of Brigadier General. Rotational engines assist in the fluctuation and also in the horizontal shift, it stops backwards or for front. They use helium gas , that inflates a composite structure of poliester, covered for an covering of dracon, like the real balloons. Its sustentation is originated by the horizontal movement of the airship or by the movement of the engines. Or either, to go down the air stream it is guided for top, to go up, the engine is deviated to order air for low. When one of its is sped up two engines, the airship makes a curve. The most amused is that with an airship, you can stop, go backwards, closed curves and up to one stol.