Prior to America's entry into World War II and in anticipation of the German submarine menace, NRL developed the Model ASB radar. It was the first operational U.S. airborne radar to be widely used for bombing, detection of ships and surfaced submarines, and airborne intercept. This radar saw extensive use during the war, not just by the U.S. Navy and Army Air Forces, but also by the British. It was installed almost universally in U.S. naval aircraft and became known as the "Workhorse of Naval Aviation." The Model ASB was the first radar to be used in carrier-based aircraft and was effective in attacking and destroying Japanese ship convoys in the Pacific. It was also effective against Japanese aircraft. It has been said that the ASB "was one of the most successful of all airborne surface search radars."