The Avro Lancaster is a British Second World War heavy bomber. It was designed and manufactured by Avro Aircraft. It was developed to a the same specification, as the Halifax, and the Short Stirling.The Lancaster has its origins in the twin-engine Avro Manchester which had been developed during the late 1930s in response to the Air Ministry Specification P.13/36 for a capable medium bomber for "world-wide use". Originally developed as an evolution of the Manchester (which had proved troublesome in service and was retired in 1942), the Lancaster was designed by Roy Chadwick and powered by four Rolls-Royce Merlins. It first saw service with RAF Bomber Command in 1942 and as the strategic bombing offensive over Europe gathered momentum, it was the main aircraft for the night-time bombing campaigns that followed. As increasing numbers of the type were produced, it became the principal heavy bomber used by the RAF, the RCAF and squadrons from other Commonwealth and European countries serving within the RAF, overshadowing the Halifax and Stirling.A long, unobstructed bomb bay meant that the Lancaster could take the largest bombs used by the RAF, including the 4,000 lb (1,800 kg), 8,000 lb (3,600 kg) and 12,000 lb (5,400 kg) blockbusters, loads often supplemented with smaller bombs or incendiaries. The "Lanc", as it was known colloquially, became one of the most heavily used of the Second World War night bombers, "delivering 608,612 long tons of bombs in 156,000 sorties". This is a plastic model Kit and requires model glue and paint to complete.