According to director George Lucas, the shots during the attack on the Death Star where the Rebel ships fly down the trench to attack the exhaust port are his homage to The Dam Busters, and contain a number of references to it. The formations of three ships mirror the scenes in The Dam Busters where Guy Gibson and Mickey Martin escort the other aircraft as they attack the Mohne Dam. Also, the two gun turrets defending the exhaust port mirror the two towers on the Mohne Dam where German flak guns were placed to defend the dam. Another reference is the sight used by the Rebel ships, which features two circles that come together as they approach the target - This is a reference to the use by 617 Squadron of two converging spotlights to maintain the low altitude needed to release the bombs.