 Each of the six pathfinder squadrons provided one aircraft as a shifter, which were to fly at with their bomb-sights set for , which would make the markers land a mile short of the aiming point.Just before the first wave finished bombing, the Pathfinder Shifters would aim their red target indicators at the green indicators dropped by the first wave backers-up, ensuring that their red markers would land on the new aiming point, a mile short of the previous one.The green markers had been laid accurately but one Pathfinder Shifter dropped short and three overshot by the same distance.