Pedal-Powered Airship

Guy tries to cross the English channel on a human-powered airship. His transport takes the form of a bicycle held aloft by a helium balloon the size of a bus, with the pedals driving two propellers. He puts the machine to the test in Bedfordshire's historic Cardington Hangars, where some of the world's biggest flying machines were created, and seeks some military advice on surviving crash landings.