On the morning of the third day out, 24 July 1945, about 200 to 300 miles northeast of Cape Engaño, "Underhill's" radar detected a Japanese "Dinah" reconnaissance plane circling the convoy about ten miles out. Her crew immediately manned their battle stations and ordered other escorts to air defense stations. The Japanese pilot remained out of gun range, determining the convoy's base course and relaying it to Japanese submarines in the area. After some 45 minutes, "Underhill" crew secured from battle stations and ordered the other escorts to resume assigned patrol stations. During this time, an SC had developed mechanical problems and had to be taken in tow by "PCE-872".