It was now possible to handle cargo and troop transport at the cargo and passenger terminals of all Marine air bases. In one 4-day period, early in April, approximately 2,000 replacement troops were lifted from Masan to Hoengsong by the five R5Ds. About a thousand rotated veterans were flown back on the return trips.[135]
[135] Unless otherwise specified, references to changes in 1st MAW units are derived from the historical diaries of the units concerned for February, March, and April 1951.
A further change involved the coordination of the Wing’s air control organizations. As the enemy’s air power increased, obviously the problems of UN air defense multiplied. At K-1 the Marine Ground Intercept Squadron-1 (MGCIS-1) and the Air Defense Section of Marine Tactical Air Control Squadron-2 (MTACS-2) were hard pressed to identify and control the hundreds of aircraft flying daily over Korea.
There was no adequate system of alerting these air defense stations to the effect that planes were departing or incoming. Many of them failed to send out their standard identification friend or foe (IFF) signals; and those that did so were still suspect, since U.S. electronics equipment on UN planes had fallen into enemy hands. As a consequence MGCIS-1 was kept busy vectoring air defense fighters to verify that certain bogeys were friendly transports, B-29s, or enemy bombers.[136]
[136] PacFlt Interim Rpt No. 2, II, 1038, 1039. A “bogey” is an unidentified plane.
In an effort to cope with the situation, General Harris requested that another Marine ground control intercept squadron, MGCIS-3 be sent to Korea. He desired that Marine Air Control Group-2 (MACG-2) also be made available to coordinate the Wing’s air control functions. These units sailed on 5 March from San Francisco.
Until March 1951 the Air Force’s 606th Aircraft Control and Warning Squadron had participated in the air surveillance of the Pusan area from the top of 3,000-foot Chon-San—the encroaching mountain that made K-9’s traffic pattern so hazardous. This Air Force unit displaced to Taejon early in March, and the MGCIS-1 commanding officer, Major H. E. Allen, moved his radio and radar vans to the mountain top to take over the job.[137]
[137] LtCol H. E. Allen, interv of 26 Feb 59.
General MacArthur Visits Marine Battalion
Following the occupation of Hongchon on the 15th, the Marine ground forces ran into stiffening enemy opposition during the next two days. The 2d and 3d Battalions of the 7th Marines were pinned down by intense CCF mortar and artillery fire when attacking Hill 356 ([Map 9]). Three out of six friendly 81mm mortars were knocked out on 15 March in the 3d Battalion area, and at dusk 2/7 and 3/7 had barely won a foothold on the hill.[138]