 By November, the system successfully flew the aircraft to its intended target at a range, where the distance-measuring gear would drop a bag of sand.Accuracy was within two miles (3 km) of target.Having observed the test flights, Rear Admiral Ralph Earle proposed a program to eliminate the German U-boat threat, one element of which was to use flying bombs, launched from Navy ships, to attack the submarine bases at Wilhelmshaven, Cuxhaven and Heligoland.