Airship

Airships are devices that rely on the use of a lighter-than-air mechanism to levitate and fly in a planet's atmosphere. Such mechanisms involve the use of a huge contained filled with a light medium, often a gas such as helium, hydrogen or heated air.

Airships have advantages over other flying craft, such as aeroplanes, helicopters or repulsorcraft, in that they require no energy to float in mid air and almost no energy to move around. This allows for low energy operation, stealth and evasion of electrical interference technology or anti-tractism fields. Disadvantages of airships include low speed and enormous size of the lifting gas bags relative to the load carried.