The Avro Lancaster was a British four-engine Second World War bomber aircraft made initially by Avro for the British Royal Air Force (RAF). It first saw active service in 1942, and together with the Handley-Page Halifax it was one of the main heavy bombers of the RAF, the RCAF and squadrons from other Commonwealth and European countries serving within RAF Bomber Command. The "Lanc" or "Lankie," as it became affectionately known, became the most famous and most successful of the Second World War night bombers, "delivering 608,612 tons of bombs in 156,000 sorties." Although the Lancaster was primarily a night bomber, it excelled in many other roles including daylight precision bombing, and gained worldwide renown as the "Dam Buster" used in the 1943 Operation Chastise raids on Germany's Ruhr Valley dams.
- Span: 102 ft (31.09 m)
- Length: 69 ft 5 in (21.18 m)
- Height: 19 ft 7 in (5.97 m)
- Engines: 4× Rolls-Royce Merlin XX V12 engines, 1,280 hp (954 kW) each
- Maximum Speed: 240 knots (280 mph, 450 km/h) at 15,000 ft (5,600 m)
- First Flight: 8 January 1941
- Number built: 7,377