Brabazon I at Bristol, 1947

Paul Addison.  Now the War is Over.  A Social History of Britain 1945-51.
British Broadcasting Corporation/Jonathan Cape, 1985.

Extremely technically advanced for its time, this thing was huge, but had only a capacity for 100 passengers. The prototype was completed and flown in 1949, only to prove a commercial failure when airlines felt the airliner was too large and expensive to be useful. In the end, only the single prototype was flown.  After a cost of £12 million and  only 382 hours of flying time, it was broken up in 1953 for scrap.  Sadly, something of a model for post-war Britain.

For a thorough and entertaining history of this aircraft, visit Damn Interesting:  The Plane that Flew too Soon.