The Avro Vulcan Bomber, perhaps the most famous of the British 'V bombers', is known for its distinctive howl and delta wing. In operation with the RAF for nearly three decades, it is one of the most legendary cold war jets, having long ago become a household name to those with even just a passing interest in aviation.The Avro 707 is far from a legend, but without it, there would have been no Vulcan.On 4 September 1949, the first Avro 707 performed its maiden flight from RAF Boscombe Down. Aerodynamically, it was a one-third scale version of the Vulcan and was developed to test the tailless thick delta wing configuration chosen for the bomber. Even after the Vulcan development phase was over, the four surviving 707s, in individual bright blue, red, orange and silver colour schemes, continued in use as research aircraft.David Fildes tells the story of this oft-overlooked aircraft, which facilitated the birth of an icon.