After the United States entered World War I in April 1917, "Aylwin" conducted experiments with Reginald Fessenden until January 1918. She was then sent overseas to conduct anti-submarine patrols from Queenstown, Ireland, and Plymouth. In December, she accompanied light cruiser on an inspection tour of German Baltic ports. Upon returning to the United States at the end of June 1919, "Aylwin" was placed in reserve. She was decommissioned at Philadelphia in February 1921. In July 1933 she dropped her name, becoming known only as DD-47. She was struck from the Naval Vessel Register in March 1935 and ordered scrapped in April.