The Airlander 10, a plane-airship hybrid, was recently piloted out of the UK's biggest hangar at Cardington Airfield, Bedfordshire. British firm Hybrid Air Vehicles (HAV) spent nine years developing the prototype in the Cardington hangar after the US Army ran out of money to develop it as a surveillance machine. The lengths of the four aircraft mentioned in the question -- rounded to the nearest metre -- are as follows:

HAV 304 Airlander 10 (92 metres)

Antonov An-225 Mriya (84 metres)

Boeing 777-200ER (74 metres)

Airbus A340-600 (75 metres)

Here is the Airlander 10 on its maiden flight: http://www.bbc.co.uk/news/uk-england-beds-bucks-herts-37111527

More Info: www.bbc.co.uk