If ever a bronze plaque is awarded in commemoration of the first history-making helicopter troop and supply lifts, it would be fitting to install it on Hill 884. That bleak and roadless height had its fifth large-scale operation on 24 February when Lieutenant Colonel Harold C. Howard’s 1st Battalion, 7th Marines, relieved the 2d Battalion, of that same regiment on “Mount Helicopter.” Operation ROTATE was completed without incident as further evidence that battalion reliefs by helicopter were now routine. In spite of the demands made upon HMR-161 helicopters in cold weather and mountainous terrain, it is noteworthy that no serious mechanical defects had developed. This six-month record came to an end on 24 February 1952 when Captain John R. Irwin was returning from Seoul to X-83. Warned by alarming vibrations, he landed to discover that the broken remnants of the tail assembly had dropped behind him in the snow. Four days later, while flying a load of logs for bunkers, Captain Calvin G. Alston’s aircraft was so shaken by vibrations that he suspected damage from enemy artillery fragments. He made a forced landing in the snow only to discover another instance of a tail assembly breakdown. Colonel McCutcheon grounded all HMR-161 aircraft until the trouble could be corrected. Not until 14 March, after 16 modified tail assemblies had been flown to Korea did the Marine transport helicopter squadron take to the air again. _The Five Days of Operation_ CLAM-UP Ground operations continued with little change during February and the first two weeks of March. The only departure from the well-worn tactical norm came on 10 February, when EUSAK put Operation CLAM-UP into effect across the entire UN front. The purpose was to feign a withdrawal and lure the enemy into sending out patrols which would yield prisoners to Eighth Army units. A EUSAK letter of instruction, dated 4 February 1952, asserted that “a policy of aggressive patrolling has led the enemy to rely upon our patrols for the maintenance of contact. This situation enables him to maintain contact without subjecting his troops to the hazard of capture or casualty.”[352] [352] This section, unless otherwise specified, is based upon the 1stMarDiv _HD_, Feb 52, 1–12; and _PacFlt Interim Rpt_ No. 4, 9–11 to 9–14. All corps were directed to “... attempt to decoy the enemy into dispatching patrols against our lines and ambush and capture such patrols.”