"Sydney" began her third patrol on 5 November, operating on the west coast of Korea and escorted by the Canadian destroyers , and , and American destroyers and . On the same day, the first RAN casualty of the war occurred, when a Sea Fury pilot failed to pull up from a strafing run and crashed. Despite foul weather, the carrier's aircraft continued to attack lines of supply and communication, and provide support to United Nations ships: the 1000th combat sortie was flown on 12 November, a day before the patrol's end. On 18 November, after replenishing in Sasebo, "Sydney", "Tobruk", and the British light cruiser sailed to Hŭngnam, where they joined Task Force 95.8 to aid a USN bombardment of Hŭngnam during 20–22 November. On that day, "Sydney" was being refuelled by when there was an accident that resulted in a large spill of fuel and damage to "Wave Chiefs" refuelling rig. Aircraft from "Sydney" performed strikes against coastal artillery batteries, barracks, industrial areas and railway lines, and provided a combat air patrol for the ships. At the conclusion of the operation, "Sydney" returned to the west coast, but was unable to resume operations because of snow and high winds until 27 November, a day before being relieved.