[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.
Even though the Corsairs at K-18 were less than 50 miles from the 1st Marine Division, very few were available to the Marines. Operation STRANGLE, in full swing, was not achieving the desired results. Since sightings of enemy vehicles were increasing, more and more Marine and Navy air sorties were channeled into interdiction. During 18 days of rugged fighting from 3 to 21 September, forward air controllers made 182 tactical air requests. Fighter-bombers were provided on 127 of these requests; however, in only 24 instances did the planes arrive when needed. The average delay time in getting CAS in response to requests during September was slightly less than two hours, but in 49 cases the planes were more than two hours late.[280] As a consequence, General Thomas reported, many of the 1,621 casualties suffered by the 1st Marine Division during the hard fighting in September were due to inadequate close air support. Furthermore, he said, the tactical capabilities of his battalions were strongly restricted.
[280] PacFlt Interim Rpt No. 3, Chap. 9, 9–14.
During the planning of attacks, infantry commanders almost always desired and requested close air support. It was also desirable to have planes on station overhead should an immediate CAS need arise, for the lack of an air strike when needed could jeopardize success. However, with restricted availability of CAS planes due to participation in STRANGLE, many times desired air cover was not to be had. Attacks under those circumstances were often costly.