A specially adapted Lancaster bomber – Type 464 (Provisioning) – carrying an Upkeep depth charge for use against German dams. This was the Barnes Wallis-designed weapon that the RAF’s 617 “Dambusters” Squadron used against the Ruhr dams during World War II. This Flight Artworks image features Lancaster ED912/G, coded AJ-N, as flown by the Australian Les Knight in May 1943. This was the third aircraft on Operation Chastise to attack the Eder Dam – it was also the last with a weapon. Knight and his crew performed a perfect low-level attack, hitting the dam and breaching it.