Jumbo craft built for war

The aircraft was originally developed for the US military which planned to use it for surveillance in Afghanistan, until the programme was scrapped three years ago.

It can reach 16,000ft, travel at up to 90mph and stay aloft for up to two weeks unmanned.

The aircraft uses less fuel than a plane, but can carry up to ten tonnes of passengers or cargo – more than regular airships.

Weighing 20,000kg, it can land on water by skidding.

At 302ft, it is about 50ft longer than the biggest passenger jets.

Potential uses include as a command centre for rescue operations, a tool for the military or to take tourists sightseeing.