Designed by Avro's Roy Chadwick to replace the Manchester, the Lancaster four-engine bomber became the RAF's main heavy bomber during WWII. The most successful night bomber of WWII, it flew over 150,000 sorties over occupied Europe and delivered over 600,000 long tons of bombs. The "Lanc's" large bomb bay meant that it could carry the largest bombs in RAF inventory including the 12,000 lb "blockbuster" type called the "Tallboy", the "Grand Slam" 22,000...