In support of the three infantry regiments were the artillerymen, guns, and howitzers of Colonel Mills’ 11th Marines. Two of its three light battalions, 1/11 and 3/11, provided 105mm direct fires to the 5th and 1st Marines, respectively. The general support battalion was 2/11, prepared to reinforce the fires of 1/11. The regimental medium battalion, 4/11, was in general support of the division, as was the 1st 4.5-inch Rocket Battery. To the southwest of the division sector, the 75mm guns of the 1st KMC Artillery Battalion, also attached to the 11th Marines, were in direct support of the 1st KMC/RCT. Newly formed the preceding month, the 1st Provisional Antiaircraft Artillery-Automatic Weapons Platoon had the mission of defending two of the Imjin River Bridges--Freedom and Spoonbill--in the division sector. [Illustration: MAP 23 K. WHITE 1ST MARINES MLR SECTOR (Division Center) 26 March 1953] In addition to organic and attached units of the 11th, four I Corps artillery components, located within division territory, further reinforced 11th Marines capabilities. The 623d Field Artillery Battalion, with batteries in the 5th and 7th Marines sectors, like 4/11 consisted of 155mm howitzers. Three heavy artillery units were also available for counterbattery missions. These 8-inch howitzers belonged to Battery C of the 17th Field Artillery, Battery B of the 204th Field Artillery, and the 158th Field Artillery Battalion. These Army units were assigned to general support of I Corps, reinforcing Marine fires on call, and were under operational control of the 159th Field Artillery Battalion Group. Active armored support for the division’s ground troops during March was provided by three of the four companies from the 1st Tank Battalion. Company A’s M-46s, flame tanks, and retrievers, well forward in the right sector, were in direct support of the 5th Marines; Company D tanks were assigned to the 1st Marines. Company B functioned as the forward reserve unit, ready to move into firing positions on the MLR if the tactical situation called for it. The rear reserve unit, Company C, conducted refresher training and performed equipment checks on the rest of the battalion tanks. The battalion commander, since May 1952, was Lieutenant Colonel John I. Williamson. The 1st Marine Aircraft Wing, with a personnel strength of 6,400, was located throughout Korea. Wing headquarters, Marine Air Control Group 2, and Marine Air Group 33, with its F9F day jet fighters and the VMJ-1 photo reconnaissance squadron operated from K-3, Pohang. VMF(N)-513, with all weather jet fighters, flew out of K-8, Kunsan, on the west coast, 105 miles below Seoul. MAG-12 and its squadrons of attack ADs and Corsairs was relatively near the 1st Marine Division sector, at K-6, Pyongtaek, 30 miles southeast of Inchon. Marine Wing Service Squadron 1, with its heavy maintenance capability, remained at Itami, Japan.