Dirigible drones – Blimps

Blimps are actually pretty great. They can stay aloft for extremely extended periods of time. They are very stable as well. However, they can be a bit of an eyesore to landscapes as they have to be quite large to carry any sort of payload. The following image shows a Navy dirigible drone:

There are some other drawbacks to dirigible drones. They must be inflated, costing large amounts of money each time you fly in whatever lighter-than-air gas you choose to use (helium, hydrogen, and so on). They are also highly susceptible to strong wind currents (due to their lighter-than-air nature). So, strong engines must be employed to counteract those currents. This adds more weight and therefore more size to the blimp. Due to these limitations and costs, dirigibles are not widely used.

It's a shame, because mechanically, they are the simplest drones to design. It is just that in practice, they are expensive and largely impractical.