It was the first opportunity for HMR-161 to try out improvements in helicopter “flying crane” techniques credited to Major Charles E. Cornwell. He had adapted the underslung nets, controlled manually from the cabin, which did a better job than the pallet, or portable platform, for many types of cargo. An average altitude of 2,300 feet for the five landing places made it necessary to reduce the payload to 850 pounds. Yet HMR-161 handled the assignment during the first week of 1952 with about one-third of its aircraft while the remainder went about routine chores. So well did four helicopters keep ahead of schedule that sometimes they flew in more cargo than could be immediately unloaded at the objectives. Following are the statistics of the seven days: Pounds lifted, 150,730; Hours of flight time, 91.7; Loads lifted, 219; Average of miles flown, 9.6 Three days later, Operation CHANGIE-CHANGIE began on 10 January 1952. Like Operation BUMBLEBEE three months earlier, this was a battalion relief lift. Yet it differed from its predecessors in that troops were to be flown from Field X-83 to sites on the company instead of battalion level, the former being only 200 yards behind the front line.[351] [351] Sources for the helicopter operations described in this section are the following: HMR-161, _HD_, Jan and Feb 51; _Cavalry of the Sky_, 176–175. Veterans of the Korean conflict will recall that “changie-changie” meant “swap” in the pidgin English serving as a conversational medium between Americans and Orientals. Hence it was applicable to a relief operation. In December the loading zone and landing site duties formerly assigned to a platoon of the 1st Shore Party Battalion, were taken over by the 1st Air Delivery Platoon, Service Command, FMFPac. First Lieutenant William A. Reavis and 35 enlisted men had a mission “to prepare and deliver supplies by air, whether by parachute, air freight, or helicopter.” These specialists were in charge during Operation CHANGIE-CHANGIE when the 2d Battalion, 7th Marines (Lieutenant Colonel Edward G. Kurdziel) relieved Lieutenant Colonel Norton’s 1st Battalion, 5th Marines. The operation was conducted smoothly by helicopters flying in defilade throughout the approach, landing, and return phases. Operation MOUSETRAP, from 14 to 17 January, was planned primarily as a test of the ability of HMR-161 to launch an antiguerrilla attack on short notice. Colonel McCutcheon and Lieutenant Colonel Mitchell were alerted at 0100 in regard to a two-company lift scheduled for 1000 that same morning. With “only minor difficulties” they transported 500 Marines to a landing site cleared by the Air Delivery Platoon. Three similar troop movements were completed by HMR-161 during the next three days.