1) Operate anywhere in the world.
2) Carry the widest range of stores possible without modifying the bomb bay.
3) Have the fastest cruising speed possible to reduce the time spent over enemy territory.
4) Defend itself using modern power operated turrets.
5) Be easily converted into a troop carrier.
6) Carry no less than 8000 lbs of stores, with the provision to carry two 18' torpedo's.
7) Be launched into the air by catapult if considered necessary!!
8) Use the new Rolls Royce 'X' twenty four cylinder engine.
Roy Chadwick the chief designer of A. V. Roe's set out to meet the requirements in full. In doing so he produced a potentially outstanding aircraft, the design of which was dominated by a vast, hugely strong bomb bay and centre section in order to meet the torpedo and catapult launch requirements. Unlike most bomb bays of this period the Manchester's bomb bay was not divided up into cells or compartments, and was a cavernous empty space into which any concievable weapon of this time could be placed.
The Achilles heel of the Manchester was the engine. Rolls Royce had schemed a very ambitious engine by mating two Rolls Royce Peregines V12's around a common crank of fiendish complexity. It should be remembered that the unreliable Peregrine had already damaged the prospects of another promising British warplane, the Westland Whirlwind and combining two of them was asking for trouble. The new engine was named 'Vulture'. From the beginning Roy Chadwick was sceptical of Rolls Royces claims for the new engine and schemed an alternative based on four Rolls Royce Merlins.
The first flight of the Avro type 679, now named Manchester in honour of the city of it's birth was delayed by engine problems until July 1939, and the first production Manchester delivered to Boscombe Down for service evaluation on 5th August 1940. Finally, the Manchester entered service with the RAF with 207 Squadron at Waddington in November 1940. In RAF service the unfortunate Manchester gained the reputation as a deathtrap. This reputation was due almost exclusively to the engines. The Rolls Royce Vulture was chronically unreliable, and never delivered the promised power. The Manchester frequently could not maintain altitude on one engine. The aircraft did improve with time and effort and by the late summer of 1941 the Manchester was operating at 14,000ft over Germany, cleared to carry the maximum bomb load of 14,000 lb's. In all, the Manchester was operated by eight front line squadrons, with the final Manchester operation being carried out on the night of 25/26 June 1942 when a single Manchester of 83 squaron took part in a raid on Bremen.
A very great man once said 'There's no success like failure' and this is especially true of Roy Chadwicks original design. The four engined derivative of the Manchester, the Lancaster was everything the Manchester should have been and more and by 1941 was replacing the Manchester in production. The Avro Lancaster is generally regarded as the finest bomber of World War Two.