Avro Manchester - Harry Holmes.  Designed by Roy Chadwick (specification Avro 679).  Designed to be powered by the Vulture (Rolls-Royce 24 cylinder ‘X’ configuration) but development problems (with the Vulture) forced Avro to look at the Napier Sabre and Bristol Centaurus.  Prototype (L7246), powered by two Vultures, flew on the afternoon of the 25th July 1939.  Soon clear that performance was a problem.  Small area on twin tails created a stability problem, a central fin was added to the fuselage.