After repairs and training at Manus, "Long" departed 23 December to sweep for the landings at Lingayen Gulf, Luzon; her group was attacked 2 January 1945 in the Mindanao Sea in the first of the frequent air raids with which the Japanese attempted to repel the invasion of Luzon. "Long" began mine sweeps in Lingayen Gulf 6 January, evading and firing upon Japanese aircraft as she carried out her intricate mission. Shortly after noon, beginning her second run, "Long" spotted two Mitsubishi A6M Zeros heading for her.