 Complete the following phrase:  After a restricted availability to repair a damaged rotor blade in her port turbine, Duluth sailed for another WestPac deployment on 1 October 1971. The ship loaded elements of BLT 2nd Battalion, 4th Marines at Okinawa on 18 October before resuming Da Nang logistics support operations out of Subic Bay. The LPD delivered vehicles, equipment and humanitarian supplies to Da Nang and embarked deck cargo and damaged PTFs for return to Subic. The LPD remained there until through the winter, conducting the occasional amphibious exercise in the Philippines and transporting troops and supplies between Subic Bay and Buckner Bay. On 1 April, following the outbreak of the North Vietnamese Easter Offensive, Duluth sailed to a holding station off South Vietnam to await developments. With the North Vietnamese offensive blunted by the end of the month, the LPD steamed to Subic Bay for rest and relaxation, 821 May. Returning to Vietnam, Duluth embarked 300 South Vietnamese marines at Tan My and landed them in Quảng Trị Province on the 24th, during which operation Duluth took desultory enemy fire from a shore battery. The LPD conducted a similar mission in early July, when Marine helicopters deployed South Vietnamese marines during 