General Harris’ plan for VMF(N)-542 to take over the duties of VMF(N)-513 at Itazuke had the approval of General Partridge. This made it possible to send the latter squadron to K-9 at Pusan to replace the VMF-311 jets, which in turn left for Itami to await corrections of engineering defects. VMF(N)-513 flew its first combat missions from K-9 on 22 January. These consisted of routine armed reconnaissance flights and an occasional deep support mission for the Eighth Army. Not until the 25th did the squadron respond to a request from Marine ground forces. And out of 49 combat missions (110 sorties) during the remaining 6 days of the month, only three (10 sorties) were in support of the 1st Marine Division. For routine operations the Marine ground forces found the support of VMO-6 sufficient. The nimble little OY observation planes were ideal for seeking out an enemy who had to be caught before he could be fought. And the helicopters did their part by dropping supplies, evacuating casualties, and laying wire. Meanwhile, the 1st Marine Aircraft Wing strengthened its administrative ties with the 1st Marine Division. Although the two organizations had no common operational commander other than General MacArthur, they maintained a close liaison. Harris attached two TBM Avengers to VMO-6 for use as radio relays when ground-to-ground communications failed in the mountainous Pohang-Andong area. He also set up daily courier flights, at General Smith’s request, to provide fast administrative liaison between widely dispersed Marine air and ground units in Korea and Japan. _Operations_ THUNDERBOLT _and_ ROUNDUP On 25 January two corps of the Eighth Army jumped off in Operation THUNDERBOLT. Advancing side by side, I Corps and IX Corps had orders to launch limited objective attacks and regain solid contact with the enemy, who was obviously preparing for a new offensive. The EUSAK commander moved his CP from Taegu to Chonan (Map 1), the I Corps headquarters, in order to maintain personal control of the operation. He requested the Navy to step up offshore patrolling on the west coast as left-flank protection. Emphasis was also placed on aerial reconnaissance, both visual and photographic, as well as deep support directed by the Mosquitoes. Even VMF(N)-542 at Itazuke had orders to conduct long flights to Seoul and maintain continuous patrols to report any attempt of the enemy to retire across the frozen Han River. The F7F-3N pilots shot up camp areas, convoys, and other lucrative targets but found no indications of large-scale crossings over the ice.[59] So varied were the missions of the squadron that it came as no surprise to be assigned to naval gunfire spotting for the USS _St. Paul_ and the other British and American cruisers shelling Inchon. [59] VMF(N)-542 _HD_, Jan 51.