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 design. Perhaps this is just as well because Avro was instructed to start building the Handley Page Halifax on 29th July 1940. Undeterred, Dobson and Chadwick presented Avro’s work on the four-engined bomber to the Air Ministry and an order for two prototypes was agreed.
The new bomber was referred to as the Manchester III for security reasons and work on the prototype commenced at Chadderton. The aeroplane would eventually be transferred to Ringway for its maiden flight (work to concrete the runways at Avro’s Woodford assembly plant were ongoing at this time).
On the evening of the 5th December 1940 work to dismantle the aeroplane for transportation to Ringway was interrupted by an air raid. Undeterred, the work continued under torchlight and little time was lost. Air raids continued throughout the month and made it difficult to transport new parts to Ringway but on 24th December the aeroplane was cleared for flight. Engine runs took place on 28th and 4th January before the Design Certificate for the first flight was signed on the 5th.
Foggy weather delayed the maiden flight but on the afternoon of the 9th January 1941 the aeroplane finally took to the skies. The flight was an immediate success and immediately revealed the long sought-after performance and stability. The first nine flights were completed in a little over a fortnight and the aeroplane was officially named as the Type 683 Avro Lancaster. It was delivered to Boscombe Down on 28th January and no major issues were discovered during the subsequent trials.
The Avro Lancaster went into service with the RAF in February 1942 and a grand total of 7,377 were built. At the peak of production 27 Lancasters were completed every week thanks to the simplicity of Chadwick’s design.
The Lancaster proved to be an extremely versatile aeroplane and was modified on several occasions for specialist raids. It was most famously used by 617 Squadron in the famous Dambuster Raids and also sank the German battleship Tirpitz with the 12,000 lb ‘Tallboy’ bombs. However, it was again thanks to Chadwick’s design that the Lancaster excelled as a conventional bomber. The fuselage was able to accommodate a cavernous bomb bay thanks to the fuel and oil being stored in the wings. As such, the Lancaster carried two thirds of the total bombload dropped over mainland Europe by the RAF.
In his book ‘Bomber Offensive’, Marshal of the Royal Air Force Sir Arthur Harris wrote: “this emergency design turned out to be without exception the finest bomber of the war”. It is of course to the credit of the whole team at Avro from this time that this praise is given.