1st MAW squadrons were kept busy furnishing close air support to the 2d Infantry Division and the two ROK divisions hit by the enemy’s May offensive. Because of the patrolling in the Marine sector, the OYs of VMO-6 took over much of the task of controlling air strikes. They flew cover for the infantry-tank patrols, and in the distant areas controlled almost as many air strikes as they did artillery missions. From the 1st to the 23d of May, VMO-6 observers controlled 54 air strikes involving 189 UN planes--159 Navy and Marine F4Us, F9Fs, and ADs, and 30 Air Force F-80s, F-84s, and F-51s. About 40 percent of the aircraft controlled by the OYs were non-Marine planes.[200] [200] VMO-6 _HD_, May 51. On the 18th the 1st Marine Division, carrying out X Corps orders, began a maneuver designed to aid the U.S. 2d Infantry Division on the east by narrowing its front. The 7th Marines pulled back to NO NAME Line to relieve the 1st Marines, which side-slipped to the east to take over an area held by the 9th Infantry. The 5th Marines then swung around from the Division left flank to the extreme right and relieved another Army regiment, the 38th Infantry. This permitted the 2d Infantry Division to face east and repulse attacks from that direction. By noon on 19 May the enemy’s renewed Fifth Phase Offensive had lost most of its momentum as CCF supplies dwindled to a trickle along a tenuous line of communications. That same day, when Colonel Wilburt S. Brown took over the command of the 1st Marines from Colonel McAlister, all four Marine regiments were in line--from left to right, the KMCs, the 7th Marines, the 1st Marines, and the 5th Marines. A new NO NAME Line ran more in a east-west direction than the old one with its northeast to southwest slant. Thus in the east of the Marine sector the line was moved back some 4,000 yards while remaining virtually unchanged in the west. Enough enemy pressure was still being felt by the 2d Infantry Division so that General Van Fleet ordered a limited offensive by IX Corps to divert some of the CCF strength. While the rest of the 1st Marine Division stood fast, the KMC Regiment advanced with IX Corps elements. At the other end of the line the Marines had the second of their two fights during the CCF offensive. Major Morse L. Holliday’s 3/5 became engaged at 0445 on the 20th with elements of the 44th CCF Division. Chinese in regimental strength were apparently on the way to occupy the positions of the Marine battalion, unaware of its presence. This mistake cost them dearly when 3/5 opened up with every weapon at its disposal while requesting the support of Marine air, rockets, and artillery. The slaughter lasted until 0930, when the last of the routed Chinese escaped into the hills. Fifteen were taken prisoner and 152 dead were counted in front of the Marine positions.[201] [201] 5thMar _HD_, May 51.