This view of a Norden bombsight shows the front of the device, with the (functional) gyroscope assembly visible through the plexiglass window on the left. The telescope for the bombsight is toward the upper center of the bombsight. To the right are five manual controls for altitude and airspeed.

A bombsight is a device that is used to drop bombs accurately from aircraft. The Norden bombsight was a highly secret device used during World War II that allowed bomber crews to carry out daytime strategic bombing. The bombsight allowed a bomb to be dropped at exactly the right time needed to hit the target. It used a mechanical analog computer consisting of a system of gyros, motors, gears, mirrors, levels, and a telescope. The bombardier would provide the computer with the air speed, wind speed and direction, altitude, and angle of drift. With this information, the bombsight would calculate the trajectory of the bomb. As the airplane approached the target, the pilot would turn the plane over to the autopilot that would fly the plane to the precise location and release the bomb over the target. Supposedly, use of the bombsight could place a bomb side a 100-foot (30-meter) circle from four miles (six kilometers) high.

The bombsight was so secret that it would be loaded onto the plane under armed guard just before it took off and removed as soon as the plane landed. Crewmembers serving on planes with the bombsight had to take an oath to protect the bombsight with their lives if necessary.

The Bombardier's Oath

Mindful of the secret trust about to be placed in me by my Commander in Chief, the President of the United States, by whose direction I have been chosen for bombardier training... and mindful of the fact that I am to become guardian of one of my country's most priceless military assets, the American bombsight... I do here, in the presence of Almighty God, swear by the Bombardier's Code of Honor to keep inviolate the secrecy of any and all confidential information revealed to me, and further to uphold the honor and integrity of the Army Air Forces, if need be, with my life itself.

Carl Norden, a Dutch engineer educated in Switzerland who came to the United States in 1904, designed the bombsight for use on U.S. naval aircraft.

The bombsight was used on the Enola Gay on August 6, 1945, to drop the atomic bomb on Hiroshima.