Two specially adapted Lancaster bombers - Type 464 (Provisioning) - carrying Upkeep depth charges. This was the Barnes Wallis-designed "bouncing bomb" that the RAF’s 617 “Dambusters” Squadron used against the Ruhr dams during World War II.

This Flight Artworks image features Lancaster ED932/G, coded AJ-G, as flown by the leader of the operation, Wing Commander Guy Gibson, in May 1943. Alongside is ED912/G, AJ-N, as piloted by Les Knight. This was the aircraft on Operation Chastise that successfully breached the Eder Dam.

The most obvious adaptation to accommodate the secret weapon was the cutting away of the bomb bays. Also very noticeable: the removal of the mid-upper gun turret to save weight. More subtly, the aircraft had a more bulbous style of bomb aimer's blister, later fitted to all Lancasters. And they were fitted with downward-pointing spotlights, offset to starboard, to gauge a 60ft altitude over water.