Sperry S-1 Bombsight The Sperry S-1 precision bombsight was developed in the 1930s. It was designated as "standard" equipment in March 1941 and was used in some U.S. Army Air Forces bombers early in World War II; however, all contracts for production of the Sperry sight were ordered canceled in late 1943. Use of the better-known Norden M-1 bombsight continued throughout the war. Click here to return to the World War II Gallery.