Aerodynamic flying funds
Aerodynamic flying funds should spend about two-thirds of the engine thrust to maintain its weight in air. The airship can stay aloft almost "free" due to the lift gas. However, this buoyancy is for hydrogen and helium, only about 1 kg per cubic meter, so the size of zeppelins is much higher than the planes and helicopters.
Drag the airship over the drag of a similar duty on the aircraft in dozens of times. Of course, helicopters are also relatively slow compared with the aircraft, and airships are much quieter and more stable the helicopter, which indicates the possibility of using airships as an "air limousine" (as used by the German Zeppelin NT).
Another important feature of airships is that, on the one hand, while increasing the size they become more and more lifting and more cost-effective (the volume is growing faster than the surface area of the shell). On the other hand, large size airships require the creation of highly specialized and very expensive infrastructure for their maintenance and repair.
Special airship hangar capacity of several hundred tons at a cost much (hundreds of times) higher than the aircraft hanger and small airships, and he can not be replaced by a relatively simple storage and raw space (which is possible in a modern light aircraft).
Therefore, the scope of the airship is now reduced to recycling the possibilities of using small and relatively inexpensive airships, while also creating the current potential of airships highest capacity at present is only the subject of numerous studies and publications in the media.
Practical attempts to create a modern zeppelin, heavy-duty, such as, for example, Cargolifter AG, in the past did not succeed due to lack of investment and the underestimation of the complexities of the project founders.