Both MGCIS-1 and MTACS-2 were already ashore at Inchon under the operational control of the 1st Marine Division. Aircraft and flight echelons of the tactical squadrons were to be flown to Kimpo on the 19th from Itazuke and Itami airfields in Japan, with the remaining elements following by surface shipping. Thus MAG-33 would consist of these units:
| Organization | Officers | Enlisted | Total |
| HqSq-33 | 74 | 177 | 251 |
| SMS-33 | 29 | 538 | 567 |
| VMF-212 | 32 | 154 | 186 |
| VMF-312 | 53 | 221 | 274 |
| VMF(N)-542 | 54 | 291 | 345 |
| MTACS-2 | 34 | 190 | 224 |
| MGCIS-1 | 19 | 185 | 204 |
| Total | 295 | 1,756 | [253]2,051 |
[253] 1st MAW SAR, Annex Item.
VMFs-214 and 323 would continue to operate from the carriers Sicily and Badoeng Strait, with the night-fighters, VMF(N)-513 being based as usual at Itazuke AFB in Japan. The only difference was that a scratch of the pen had transferred these units from MAG-33 to MAG-12. It was their responsibility to support the advancing ground forces during the critical period while the other three tactical squadrons were making the move from Japan to Kimpo.
Control of tactical air support had passed from the TADC on the Mount McKinley to the Air Support Section of MTACS-2 on D-plus 2, after the Landing Force Commander signified his readiness to assume it. Calls for close air support were increasing as the enemy recovered from the first shock of invasion. On the 18th and 19th, the three fighter squadrons of MAG-12 flew a total of nearly 50 close support sorties controlled by the Air Support Section of MTACS-2. Napalm, 20mm ammunition, rockets, and 500-pound bombs were used to blast NKPA troop concentrations in the zone of the 1st Marines.[254]
[254] MarCorps Board Study, IV-B, 16, 17; 1st MAW SAR, basic rpt, and Annex Jig.
Logistical as well as tactical and administrative problems had to be solved. During the planning phase, it may be recalled, Colonel Kenneth H. Weir (C/S TAC X corps) had learned that X corps would not have enough trucks to support air operations at Kimpo by transporting aviation gasoline and aircraft munitions from Inchon. As a solution, arrangements were made to accept the offer of FEAF Combat Cargo Command to provide logistical support; and these totals in tonnage were flown in from Japan during the first week:
| Date | Ammo | Avgas | Oil |
| 18 Sep | 16 | 8 | 0 |
| 19 Sep | 73 | 28 | 5 |
| 20 Sep | 151 | 86 | 0 |
| 21 Sep | 219 | 88 | 11 |
| 22 Sep | 268 | 153 | 5 |
| 23 Sep | 139 | 80 | 0 |
| 24 Sep | 118 | 81 | [255]16 |
[255] 1st MAW SAR, basic rpt.
This proved to be the largest total for a single week during the Inchon-Seoul operation. In addition, about 1,025 tons of POL and 425 tons of ammunition were trucked from Inchon to Kimpo during the entire period, and the forward echelon of VMR-152 flew in spare parts and items of urgently needed equipment.