Relieved by "Chicago" on 1 August, "Biddle" dropped the fishermen off at Danang and then headed for the Philippines. The warship spent a week at Subic Bay and three days at Manila before heading back to Vietnam on 13 August. On 15 August, she relieved "Chicago" on station in the Gulf of Tonkin. She served as strike-support and search-and-rescue ship until 22 August when she relieved "Chicago" as PIRAZ (Positive Identification Radar Advisory Zone) ship. The warship alternated between those two tasks until 10 September when she was relieved on PIRAZ station by the destroyer . The guided-missile frigate entered Yokosuka, Japan on 14 September, after a brief stop at Subic Bay to disembark her helicopter detachment.