反潛作戰
In 1942 when the United States was preparing to fight a long, technically challenging war, Hilliard left MGM to join his friend Blackburn who had begun research for Massachusetts Institute of Technology (MIT) to work on radar development for U.S. military applications. His work at MIT in Cambridge, Massachusetts led in 1943 to an employment opportunity back in Los Angeles at Altec Lansing where he improved their Magnetic Anomaly Detector (MAD, also known as "Magnetic Airborne Detection") system for Anti-submarine warfare (ASW).