Measures were also taken during this interlude to strengthen the airfield’s defenses. Expecting that the Viet Cong might attempt to infiltrate the Marine position, Colonel Carey created a 40-man security unit to protect the inner camp and flight lines. This unit, composed of men from MABS-16 and HMM-362 and responsible to a permanent sergeant-of-the-guard, maintained roving patrols and security posts during hours of darkness. A network of concertina wire, trip flares, and machine gun emplacements provided additional protection around the helicopters and living area. Attack alerts were conducted periodically to coordinate the ARVN’s outer defenses and the Marine guard within the perimeter. [Illustration: III CORPS TACTICAL ZONE 1962 ] Within less than two weeks after the first Marines had arrived at Soc Trang, the camp had been adequately prepared to support sustained combat helicopter operations. In addition, defenses had been established and the lines of logistical support from MACV had been opened. Food and water were readily available. All necessary liaison with the Vietnamese units to be supported had been accomplished. Pilots and crews had gained a rudimentary knowledge of the area in which they would fly and SHUFLY’s entire command structure had undergone a one week “shake down” in which it had proven sound. _Mekong Delta Combat Support Operations_ Lieutenant Colonel Clapp’s squadron began combat operations on Easter Sunday, 22 April, exactly one week after arriving in the Republic of Vietnam. The unit’s first combat assignment was to assist the Army’s Saigon-based 57th Helicopter Company in an operation code named LOCKJAW. The American helicopters were to support the ARVN 7th Division which was headquartered at My Tho, 53 miles northeast of Soc Trang. The Marine helicopters, which departed Soc Trang at 0900, flew 29 sorties and lifted 400 Vietnamese soldiers without incident during the course of their first operation. Unlike the U.S. Army helicopters already operating in other parts of South Vietnam, the Marine HUS-1s were not armed with machine guns during their initial operations from Soc Trang. Prior to their deployment, the Marine commanders had reasoned that weapons mounted in the cargo hatch would hinder loading and unloading during critical periods while the helicopters were in landing zones. Additionally, armed aircraft would tend to present a more hostile appearance to Vietnamese civilians, thereby providing the Viet Cong ready-made material for their anti-American propaganda themes. The only weapons on board the helicopters, therefore, were the individual side arms and two M3A1 .45 caliber submachine guns carried by the crew members. The automatic weapons enabled Lieutenant Colonel Clapp’s men to return fire at short ranges and would also enhance their survival capabilities in the event an aircraft was forced down in unsecure territory.[5-C]