_VMF(N)-513_--Lieutenant Colonel Ross S. Mickey vice Lieutenant Colonel Conley, on 6 May; in June, Lieutenant Colonel Robert L. Conrad, acting CO, named CO for Lieutenant Colonel Mickey, hospitalized for injuries received in a May aircraft accident; _VMJ-1_--Lieutenant Colonel Leslie T. Bryan, Jr. vice Lieutenant Colonel William M. Ritchey, on 15 May; _VMF-311_--Lieutenant Colonel Arthur M. Moran vice Lieutenant Colonel Coss, on 21 April; Lieutenant Colonel Bernard McShane vice Lieutenant Colonel Moran, on 1 June; _VMF-115_--Lieutenant Colonel Lynn H. Stewart vice Lieutenant Colonel Warren, 5 June. With respect to CAS activities, excellent weather in April--only a single day of restricted flying--brought the 1st MAW air tally that month for its land-based squadrons to 3,850 effective combat sorties (440 more by VMA-312) and 7,052.8 combat hours. This was a substantial increase over the preceding months. Not surprisingly, the average daily sortie rate for the month was correspondingly high: 128.3. Of 1,319 CAS sorties the largest proportion, 579 and 424 (43.9 percent, 32.1 percent), were for Marine and ROK operations, respectively. The outstanding day of the month was 17 April. During the 24-hour reporting period, 262 sorties were completed by MAGs-33 and -12 pilots,[455] who expended a combined total of 228.3 tons of bombs and 28,385 rounds of 20mm ammunition. For the two MAG-33 fighter bomber squadrons, it represented maximum effort day. Preparation had been made a week earlier to devise the targeting and best all-round flight schedules for ordnance and line sections. Objective areas for the mass attack were picked by the wing G-3 target selection branch and approved by the EUSAK-Fifth Air Force JOC. It was decided that “flights of eight aircraft staggered throughout the day would offer the best efficiency in expediting reloading and refueling with not more than sixteen aircraft inactive on the flight line at one time.”[456] Throughout the day, from 0410 to 2030, VMFs-311 and -115 continuously pounded designated targets in support of the U.S. 7th and 3d Infantry Divisions.[457] Commented MAG-33: [455] Between 15–18 April the west coast carrier squadron was under a FEAF order restricting normal interdiction missions. This was to protect UNC sick and wounded POWs in transit from China to Kaesong for final exchange at Panmunjom. VMA-312 air operations were held to CAS along the bombline. “Marine fliers of the ‘Checkerboard’ squadron proved adept at this unusual role [CAS support missions along the front lines], and received a ‘well done’ from JOC Korea as the Corsairs flew more than 100 close air support sorties from 16–18 April.” _PacFlt EvalRpt_ No. 6, Chap. 10, p. 10-110. [456] MAG-33 ComdD, Apr 53, p. 51.