The Avro Lancaster is a British four-engined Second World War heavy bomber designed and built by Avro for the Royal Air Force (RAF). It first saw active service with RAF Bomber Command in 1942 and, as the strategic bombing offensive over Europe gathered momentum, it became the main heavy bomber used by the RAF, the RCAF, and squadrons from other Commonwealth and European countries serving within the RAF, overshadowing its close contemporaries the Handley Page Halifax and Short Stirling. The "Lanc", as it was affectionately known, thus became the most famous and most successful of the Second World War night bombers, "delivering 608,612 tons of bombs in 156,000 sorties."

The Lancaster, an evolution of the troublesome Avro Manchester, was designed by Roy Chadwick and was powered by four Rolls-Royce Merlins, or, in one version, Bristol Hercules engines.

A long, unobstructed bomb-bay meant that the Lancaster could take even the largest bombs used by the RAF, including, the 4,000 lb (1,812 kg), 8,000 lb (3,629 kg), or 12,000 lb (5,443 kg) Blockbusters, loads often supplemented with smaller bombs or incendiaries. The versatility of the Lancaster was such that it was chosen to equip 617 Squadron, and was modified to carry the Barnes Wallis designed Upkeep "Bouncing bomb" for Operation Chastise, the attack on Germany's Ruhr Valley dams. Although the Lancaster was primarily a night bomber, it excelled in many other roles, including daylight precision bombing: in the latter role some Lancasters were adapted to carry the 12,000 lb (5,443 kg) Tallboy and, ultimately, the 22,000 lb (9,979 kg) Grand Slam "earthquake" bombs (also designed by Wallis).

Grant McLean, CM (April 7, 1921 – December 19, 2002) was a Canadian film director and producer. For most of his professional career he worked with the National Film Board of Canada (NFB), serving as its acting Commissioner for a period during the 1960s.

McLean was born in Yorkton, Saskatchewan. His father Allan Grant McLean was a grain commissioner and Liberal Party politician, and his uncle Ross McLean also served as chairman of the NFB.

McLean studied at the University of Toronto, before joining the NFB in 1941 as a cameraman. One of the notable productions he worked on during World War II was the documentary Target Berlin for the Canada Carries On series, which showed the building of the first Lancaster bomber to be made in Canada, with McLean later flying in the plane to capture footage of a bombing raid over Berlin in Germany. He became a film director in 1947, with his first production in this capacity being The People Between, a documentary about the Chinese Civil War. For this film he became the first Western cameraman to film Mao Zedong. He later claimed that he had not liked Mao, although he had been friendly with Zhou Enlai, whose support had been vital in enabling him to travel freely across China in the making of the film. However, The People Between was banned by the Canadian government, under pressure from the Government of the United States, due to its balanced portrayal of Communism. Some of the footage was used in the NFB documentary China in Need, and the film itself received a limited release in Europe.