Today marks the 80th anniversary of one of the most significant events in the history of military aviation when the first prototype Avro Lancaster took off from Ringway on its maiden flight.
The Avro Lancaster is one of the most famous aircraft in the world and has an unusual history in that it was developed from a twin-engined bomber doomed to failure.
On 8th September 1936, the Air Ministry released Specification P.13/36 for a twin-engined bomber in response to German rearmament. It was stipulated that the aircraft would use the new Rolls-Royce Vulture engine and must be capable of carrying an 8,000 lb bomb load.
Designing an aeroplane to meet Specification P.13/36 was a huge challenge for Avro as the company had never designed such a large aircraft. Furthermore, the design team had no experience of all-metal stressed skin construction, which would be an integral part of this aeroplane.
It is a tribute to Roy Chadwick that Avro submitted its tender in January 1937. On 30th April 1937 Avro was awarded a contract to build two prototypes of the Type 679 Avro Manchester. The design was based around the concept of simplicity, enabling the aeroplane to be mass produced and easy to repair. Both the fuselage and wings were designed to be built in sections to satisfy the Air Ministry’s transportation requirements and maximise the application of manpower. The fuel and oil tanks were located in the wings, leaving the fuselage free to carry the bombload.
On 25th July 1939, the Avro Manchester took off from Ringway (now Manchester Airport) on its maiden flight but problems with stability and take off performance immediately became apparent. Modifications to the wing and tail plane were made in an attempt to correct the instability but these in turn affected the overall performance of the aeroplane. A central fin was added to the tailplane but its performance was hampered by turbulence coming off the ventral gun turret.
The source of the problems blighting the Avro Manchester was the Rolls-Royce Vulture engine, which proved to be both heavy and unreliable. Avro was exploring the possibility of converting the Manchester into a four-engined bomber as early as February 1940 by using the Rolls-Royce Merlin XX powerplant. Stuart Davies was appointed to reorganise the Experimental Shop by Roy Dobson and work on the Lancaster had begun by the middle of April 1940. Roy Chadwick had lost all faith in the Vulture engine by June but he was convinced that the design of the airframe was sound.
The work on the Lancaster was being carried out alongside production orders for both the Manchester and Anson. The modifications to accommodate four Merlin engines were relatively simple thanks to the original concepts of the Manchester’s