Once top-secret WWII bombsights see light of day Published Aug. 24, 2010 By Carl Bergquist Air University Public Affairs MAXWELL AIR FORCE BASE, Ala. -- One of the most highly guarded secrets of World War II -- the Norden Bombsight, is on display at Air War College and Enlisted Heritage Hall. Developed by Carl Lucas Norden before the war began, the sight became the standard for bombing accuracy, and a working Norden sight was highly sought by Nazi officials. Proponents of the bombsight often claimed the accuracy was so good a pilot could "drop a bomb in a pickle barrel" from 20,000 feet. Tests by the manufacturer, under ideal conditions, proved an accuracy of within a 100-foot circle around a target from that altitude. But, actual accuracy depended on several factors: Weather; how much evasive flying was needed to avoid being shot down; and the skill of the bombardier, to name a few. According to the Hill Air Force Base, Utah, website, Mr. Norden, a Dutch engineer who was educated in Switzerland and immigrated to the U.S. in 1904, originally designed the sight for use on U.S. Navy aircraft. Ultimately, the Army also adopted the sight for its bombers. "The device used a mechanical analog computer comprised of motors, gyros, mirrors, levels, gears and a small telescope. The bombardier input the necessary information, such as airspeed, wind direction and altitude, and the bombsight would calculate the trajectory of the bomb being dropped," the site says. "Near the target, the aircraft would fly on autopilot to the precise position calculated by the bombsight and release the ordnance." The National World War II Museum credits the Norden Bombsight with, "playing a critical role in the strategic bombing campaign of World War II and continued to be used through the Korean and Vietnam Wars." The National Museum of the U.S. Air Force says, "The Norden bombsight was crucial to the success of the U.S. Army Air Forces' daylight bombing campaign during World War II. Highly classified, it gave American forces bombing accuracy unmatched by any other nation at the time." The Norden Bombsight primarily consisted of two parts: the sight head and the stabilizer. Together, their mechanical computer and gyroscopes gave the sight its accuracy by holding the aircraft on course until the bombs were released. In the final moments of the bomb run, the Norden sight actually flew the bomber. Security was so tight around the Norden Bombsight that bombardiers loaded it, under armed guard, onto the aircraft just before takeoff, and it was kept covered from view until the aircraft was in the air. Upon landing, it was immediately removed, again under armed guard, and secured in a special vault. "As a critical wartime instrument, bombardiers were required to take an oath during their training stating that they would defend the Norden secret with their own lives if necessary," says the Remembering World War Two Airmen website. "In case the bomber should make an emergency landing on enemy territory, the bombardier would have to shoot the important parts of the Norden with a gun, disabling it. But, as this method still would leave a nearly intact apparatus for the enemy, something like a thermite gun was installed. The sheer heat of the chemical reaction would melt the Norden into a lump of metal." According to the Squadron 13 website, on August 6, 1945, bombardier Maj. Thomas Ferebee used a Norden bombsight to drop the uranium bomb, Little Boy, from the B-29 Enola Gay which was flying 31,000 feet above Hiroshima, Japan. The Naval Air Observation Squadron Sixty-Seven last used Norden sights in combat during the Vietnam War. They were employed in Operation Igloo White for implanting Air-Delivered Seismic Intrusion Detectors along the Ho Chi Minh Trail. For those interested in viewing the two Norden sights, a model MK-15, Mod 7 with a Lucas Harold stabilizer is on display in the main lobby of Maxwell's Air War College. The other sight, located at Gunter's Enlisted Heritage Hall, has a Maxon X-1 Reflex Sight and a tachometer adapter for a Glide Bombing Attachment mounted on top. Both are on loan from the National Museum of the U.S. Air Force.