The Avro 679 Manchester was a British twin-engine heavy bomber developed and manufactured by the Avro aircraft company in the United Kingdom. While not being built in great numbers, it was the forerunner of the more famed and more successful four-engined Avro Lancaster, which was one of the most capable strategic bombers of the Second World War.
Avro designed the Manchester in conformance with the requirements laid out by the British Air Ministry Specification P.13/36, which sought a capable medium bomber with which to equip the Royal Air Force (RAF) and to replace its twin-engine bombers, such as the Armstrong Whitworth Whitley, Handley Page Hampden and Vickers Wellington. Performing its maiden flight on 25 July 1939, the Manchester entered squadron service in November 1940, just over twelve months after the outbreak of the war.
Operated by the RAF and the Royal Canadian Air Force (RCAF), the Manchester came to be regarded as a failure, primarily as a result of its Rolls-Royce Vulture engines, which were underdeveloped and hence underpowered and unreliable, and production was terminated in 1941. The Manchester was redesigned as a four-engined heavy bomber, powered by the Rolls-Royce Merlin engine instead, which became known as the Lancaster.
Development
The Manchester has its origins in a design produced by Avro to fulfil the British Air Ministry's Specification P.13/36. This was the same specification to which Handley Page had also produced their initial design for what would become the Halifax bomber.[1] Issued in May 1936, Specification P.13/36 called for a twin-engine monoplane "medium bomber" for "worldwide use", which was to be capable of carrying out shallow (30°) dive bombing attacks and carry heavy bomb loads (8,000 lb (3,600 kg)) or two 18 in (460 mm) torpedoes.[2][3] Provisions to conduct catapult assisted takeoffs, which would permit the carriage of the maximum payload, was another requirement, although this provision was removed in July 1938.[4] The envisioned cruising speed of the bomber was to be a minimum of 275 mph (443 km/h) at 15,000 ft (4,600 m).[5] The Air Ministry had expectations for an aircraft of similar weight to the B.1/35 specification but smaller and faster.
Avro had already started work on a corresponding design prior to having received a formal invitation to tender. The company was in competition with Boulton Paul, Bristol, Fairey, Handley Page and Shorts. Vickers also had its Warwick, which had Napier Sabre engines but eventually chose against tendering it. In early 1937, the Avro design and the rival Handley Page HP.56 were accepted and prototypes of both ordered but in mid-1937, the Air Ministry exercised their right to order the types "off the drawing board". This skipping of the usual process was necessary due to the initiation of a wider expansion of the RAF in expectation of another great European war. From 1939, it was expected that the P.13/36 would begin replacing the RAF's medium bombers, such as the Armstrong Whitworth Whitley, Handley Page Hampden and Vickers Wellington.