Invasion Nears In preparation for the invasion of France from the sea, the AAF had to photograph the entire coastline of western Europe. As the date of the invasion approached, however, it was necessary to obtain more detailed photographs of specific German beach defenses, and between May 1 and June 6, hundreds of sorties were made by unarmed photo planes flying as low as 15 feet. The information obtained from these photos was used for determining the beaches to be assaulted and the coastal defense batteries and other shore areas to be bombed. Shortly before the first troops stormed the beaches, 1,083 B-17s and B-24s plastered German defenses with 3,000 tons of bombs, accompanied by heavy naval bombardment. The heavy bombers were followed immediately by medium bombers and fighter-bombers, which not only attacked defenses on the beaches but rear target areas as well. Click here to return to the World War II Gallery. Find Out More Related Fact Sheets Boeing B-17G Flying Fortress Consolidated B-24D Liberator Note: The appearance of hyperlinks does not constitute endorsement by the National Museum of the USAF, the U.S. Air Force, or the Department of Defense, of the external website, or the information, products or services contained therein.