With the Division in reserve from 15 July until the latter part of August, close air support (CAS) was not a vital problem; however, upon return to the Punchbowl area the situation became serious. The difficulties arose from the time lag between the request for air support to the time the planes arrived over target. The 1st Marine Aircraft Wing operating under the control of the Fifth Air Force was busily employed on interdiction missions. On 30 August, a tactical air observer, spotting what appeared to be a division of NKPA troops moving toward the Marines, hurriedly flashed back a request for a multi-plane strike. The enemy troops were beyond artillery range, but they were bunched up--a good target for a concentrated air strike. It was more than three hours later that four fighter bombers arrived on the scene; by that time, the enemy formation had dispersed and the desired number of casualties could not be inflicted.[277] [277] CG 1stMarDiv ltr to CinCPacFlt, 4 Oct 51, enclosure (1) “Observations on Close Air Support for the 1st Marine Division during 5–23 September 1951.” The reason for this lack of timely air support was apparent. Most of the UN air power was being funneled into Operation STRANGLE, the interdiction operation designed to cut off the enemy’s vehicular and rail traffic in the narrow waist of North Korea. With the emphasis on air interdiction, close air support sorties were limited to only 96 per day for the entire Eighth Army.[278] The 1st Marine Division received only a proportionate share. [278] _PacFlt interim Rpt_ No. 3, VI, 6-6, 6-7; 1stMarDiv _SAR_, Jun 51. Marine close air support was needed because of the enemy’s determined resistance to the Division’s attack. The Reds hurled frequent night counterattacks and pounded the Marine positions with artillery and mortars hidden in the precipitous Punchbowl area. At one time it was estimated that the enemy was using 92 pieces of artillery. The Marines had only 72 field pieces, but in one 24-hour period they expended more than 11,000 rounds of artillery ammunition on a 6,000-yard frontage. The enemy emplacements, hewn out of solid rock, were hard to knock out. To support the hard-working infantrymen, Marine Aircraft Group 12 (MAG-12) had moved VMF-214 and VMF-312 from the Pusan area to K-18, an airfield on the east coast at Kangnung. By moving closer to the Division area, planes were able to extend their time over the target area and render more effective support to the infantry. Also, Marine Air Support Radar Team One (MASRT-1) was sent to Korea and established positions to support the Division. Using its support radar the team began to evaluate its capability of guiding unseen fighter-bombers at night or under conditions of poor visibility.[279] [279] _PacFlt Interim Rpt_ No. 3, Chap. 9, 9–18; Chap. 10, 10–12, Chap. 15, 15–20, 60–61; Gen G. C. Thomas interv, 21 Jan 59.