Between 12 April and 5 May, the night fighter squadron conducted 58 NCAS sorties in the division right sector employing this new control system with excellent results.441 The procedure was a marked success and made it possible to provide continuous 24-hour-a-day close support to Marine infantry units. It was considered a supplement to, not a replacement for the MPQ (radar controlled bombing) missions of MASRT-1. Plans called for F9F aircraft to be integrated into the program, since the F7F Tigercats were being replaced by jets. Allied psychological warfare teams on 17 April introduced a different theme in their broadcasts to the enemy: that of the dangers to the CCF from the new searchlight marking of targets. As a Marine training bulletin noted: “It is believed that this method of attack by aircraft is particularly demoralizing to the enemy because he is unable to anticipate where the strike will hit, and therefore has no means of defending himself against it.”442

Another tactical improvement about this same time dealt with artillery flak suppression in support of close support aircraft. Two refinements made in the procedure in the late spring of 1953 involved firing of HE rounds during the actual run of planes over the target. Basically, the plan consisted of releasing a TOT or VT concentration on the most lucrative enemy antiaircraft positions within a 2,500-yard circle around the strike area. A continuous rain of HE-fuzed projectiles was placed on these targets for a three-minute period, during which Marine planes made their runs.

Favorable results were achieved in that new system tended to keep enemy antiaircraft gunners off-balance for a longer period of time and thus decreased the danger to friendly attacking aircraft. On the other hand, pilots quickly noted that this became an “unimaginative employment of an unvarying flak suppression schedule which Communist AA gunners soon caught onto and turned to their own advantage.”443

With respect to squadron hardware, Marine combat potential increased substantially during the spring months with the phasing out of F7Fs in Night Fighter Squadron 513 and introduction of the new F3D-2 twin-jet Skyknight intruder. By late May the Allocation of 24 of these jet night fighters had been augmented by 4 more jets from the carrier USS Lake Champlain and the squadron “assumed its primary night-fighter mission for the first time in the Korean War.”444 While the sturdy, dependable Tigercats445 made their final contribution to the United Nations air effort early in May with the experimental NCAS program, the new Skyknights continued the squadron’s unique assignment inaugurated in late 1952 as night escort to Air Force B-29 bombers on their strike missions. Not a single B-29 was lost to enemy interceptors after 29 January 1953. The capabilities of the skilled Marine night-fighters were noted in a “well done” message received by the CO, VMF(N)-513 in April from the Air Force.446

Organizational changes within the wing included the arrival, on 29 May, of a new MAG-12 unit to replace the “Checkerboard” squadron. VMA-332 (Lieutenant Colonel John B. Berteling) was slated to operate on board the USS Bairoko (CVE-115) for the F4U carrier-based squadron VMA-312447 due for return to CONUS. Veteran of 33 months of combat while attached to the wing as West Coast (CTE 95.1.1) aerial reconnaissance and blockade squadron, VMA-312 (Lieutenant Colonel Winston E. Jewson) was officially relieved 10 June. The change, moreover, was the first phase of a new personnel policy, carrier unit rotation, that was expected to implement a unit rotation program for land-based squadrons. It was anticipated that the new unit rotation program would eliminate inherent weakness of the individual pilot rotation system and thus increase the combat effectiveness of the wing.448

During the period other organizational changes included transfer of administrative control of VMF(N)-513 on 15 May from MAG-33 to MAG-12.449 The squadron, with its new twin-engined jet fighters, moved from K-8 (Kunsan) further up the coast to the MAG-12 complex at K-6 (Pyongtaek), upon completion of the new 8,000-foot concrete runway there. This phased redeployment of nightfighter personnel and equipment began in late May and was concluded on 6 June without any interim reduction of combat commitments. Replacement of the squadron F7F-3Ns with F3D-2s was also completed in early June.

Late that month, plans were underway for two additional changes: the Marine photographic squadron, VMJ-1, was due to be separated administratively and operationally from MAG-33 on 1 July and revert to 1st MAW; and Marine Wing Service Squadron One (MWSS-1) was to be deactivated, effective 1 July.

The change of command relationships between CG, FAF and CG, 1st MAW earlier in the year450 which had restored operational control of certain designated Marine air units to the wing commander, increased the efficiency of 1st MAW operations. Despite the fact that VMJ-1 at times contributed nearly 40 percent to the total FAF input of all daylight combat photographs,451 aerial intelligence (both pre- and post-strike photos) supplied to wing and group headquarters was considered inadequate. As a MAG-33 intelligence officer commented with some exasperation as late in the war as May 1953:

Similarly, at the individual squadron level, the carrier unit VMA-312 shortly before its relief, reported: “The one limitation on squadron activities continued to be photo coverage of the strikes. With limited facilities available, the squadron has no clear cut pictures of strike results.”453 Return of VMJ-1 to operational control of General Megee ultimately “gave the Wing adequate photo-intelligence for the first time since commencement of combat operations in Korea.”454

Indoctrination of new replacement personnel within the 1st Marine Aircraft Wing took a swift upturn during the spring period. Pilots who had completed 100 combat missions were transferred to staff duty elsewhere in the wing in Korea or rotated Stateside. The average squadron personnel strength ran to 88 percent of T/O for enlisted; and officer strength, considerably less, frequently dipped as low as 61 percent. Under the 100-missions policy, it was a time of rapid turnover of unit commanders, too, as witnessed from the following squadron diary entries:

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:

VMF-115 alone, with 30 pilots and 23 aircraft, had flown 114 sorties and delivered 120 tons of bombs on North Korean targets.

A sample of the intensity of this maximum day was a series of three early-morning interdiction strikes led by three VMF-115 pilots that launched the effort. Led by Lieutenant Colonel Joe L. Warren, Major Samuel J. Mantel, Jr., and Major John F. Bolt, the 23 attacking Panther jets lashed the objective with 22.35 tons of ordnance and 4,630 rounds of 20mm ammunition. The three missions destroyed half of the buildings and inflamed 95 percent of the target area in the enemy supply concentration point T’ongch’on on the Korean east coast.

By contrast, wing operations in May were considerably hampered by the bad weather peculiar to this time of the year in Korea. Restricted flying conditions were recorded for 18 days of the month. A total of 153 CAS sorties were flown for the Marine division before its 5 May relief from the front lines. Of the wing’s 3,359 sorties459 during the month, 1,405 were for close support to forward units beating back Communist encroachment efforts. The allocation of CAS sorties was 412 for U.S. infantry divisions (including 211 for the 25th Division occupying the customary Marine sector); 153 for the 1st Commonwealth Division at the Hook which the Communists assaulted on 27–28 May as part of their overall thrust against western I Corps defenses; 412 sorties for ROK units; and 63, miscellaneous. Heaviest action for Marine aviators took place towards the end of the month to thwart enemy blows in the I Corps sector where Army and Turkish units were attempting to repulse the Chinese.

The renewed effort of the Chinese Communists against UNC ground forces in late May continued sporadically the following month. A number of new records were set by Marines flying CAS assignments under the Fifth Air Force. During the intense mid-June attacks on the ROK II Corps area and adjacent X Corps sector, MAGs-12 and -33 pilots chalked up some busy days. Between 10–17 June, Marine, Navy, and Air Force aircraft had flown 8,359 effective sorties, the bulk of this massive FAF effort to buttress the crumbling ROK defense. Of this number, Marine sorties totaled 1,156, or nearly 14 percent. (Combat sorties for the 1st MAW throughout June came to 3,276 despite 23 days of marginal to nonoperational weather.) Marine pilots scored as high as 48 percent of a single day’s interdiction strikes made by FAF. This occurred 15 June when the 1st MAW flew a record-breaking 283 sorties, followed by another peak 227 sorties the next day.

Actually, when the ground situation in the ROK II Corps front began to deteriorate on 12 June, the new Fifth Air Force commander, Lieutenant General Samuel E. Anderson, “waived the [3,000 foot] minimum-altitude restrictions on his fighter-bombers and ordered his wings to give all-out support to the Eighth Army.”460 The Seventh Fleet commander, Admiral Clark, likewise kept his carriers on line for seven days and ordered its naval pilots to “team with Marine and Fifth Air Force airmen for a close-support effort exceeding anything up to that time.”461 When the ROK II Corps defenses cracked open on 15 June, temporary clearing weather “allowed General Anderson and Admiral Clark to hit the Reds with everything they had. FEAF planes flew a total of 2,143 sorties of all kinds for the largest single day’s effort of the war.”462

Commenting on this heavy action period, 14–17 June, a dispatch to General Megee from the new FAF commander, who had succeeded General Barcus the previous month, noted:

This came, incidentally, only five days after receipt by the 1st Marine Aircraft Wing of the Korean Presidential Unit Citation.464 The award cited the wing’s “outstanding and superior performance of duty” between 27 February 1951 and 11 June 1953. During this period Marine fliers executed more than 80,000 combat sorties for UNC divisions.

The fighter-bombers of MAG-33 and the MAG-12 attack planes saw heavy action during 24–30 June when the Chinese again concentrated their attention on ROK divisions in the UNC line. Peak operational day was 30 June. Marine squadrons alone executed 301 sorties, including 28 percent of the CAS and 24 percent of total FAF interdiction missions. It was also an outstanding day for MAG-12 which “outdid itself by flying 217 combat sorties against enemy forces. The 30th of this month saw MAG-12 establish a new ordnance record when an all-time high of 340 tons of bombs and napalm were dropped on North Korea.”465 Contributing heavily to this accomplishment was Marine Attack Squadron 121. It unleashed 156 tons of ordnance, a squadron record. It was believed this also established an all-time record for tonnage expended on the enemy by a Marine single-engine propeller squadron.

Other Marine Defense Activities466

Like their counterparts on the Korean mainland, the Marines, naval gunfire teams, and ROK security troops comprising the West Coast and East Coast Island Defense Commands felt the alternating pressure build-up and slow-down that typified the closing months of the war. At both installations the defense had been recently strengthened, more or less by way of response to a CINCPacFleet intelligence evaluation in December 1952. This alerted the isolated island forces to the possibility of a renewed Communist attempt to recapture their positions. The Allied east coast defense structure at Wonsan, right at the enemy’s own front door just above the 39th Parallel, was considered particularly vulnerable.

As in the preceding months, the mission of the west coast island group remained unchanged—namely, the occupation, defense, and control of its six island components. These, it will be remembered, were: Sok-to, Cho-do, Paengyong-do (command headquarters), Yongpyong-do, and the two lesser islands at Taechong-do and Tokchok-to.467 Formal designation of the island commands was modified on 1 January 1953. At this time the West Coast and East Coast Island Defense Elements (TE 95.15 and TE 95.23) were redesignated as Task Units (TU 95.1.3 and TU 95.2.3) respectively. Korean Marines, who represented the bulk of these task units, were provided from the 2d KMC Regiment, the island security force. This unit constituted the main defense for the important U.S. Marine-controlled islands off the Korean west and east coasts.

Approximately 17 Marine officers and 100 enlisted men were assigned to the western coastal complex, with two battalions of Korean Marines fleshing out the garrison defense. The primary mission of this island group was to serve as offshore bases for UNC intelligence activities, including encouragement of friendly guerrilla operations conducted by anti-Communist North Korean personnel. Artillery based on the Marine-controlled islands provided both defensive fires and counterbattery missions against enemy guns sited on the nearby mainland.

The secondary mission of WCIDU, that of training Korean troops in infantry and weapons firing exercises, continued to be hampered somewhat by faulty communication. As one officer observed, the training program to qualify selected KMCs for naval gunfire duties “met with only modest success, due primarily to the language barrier and lack of communications equipment in the Korean Marine Corps. Personnel who had received this training did prove to be extremely helpful in accompanying raiding parties on the mainland in that they were able to call for and adjust fires.”468

Enemy pressure against the West Coast Islands, both from Communist shore guns and bombing, had increased during the fall and winter of 1952. Cho-do, shaped roughly like a giant downward-plunging fish, as previously noted had been bombed in October for the first time in the history of the command. This new trend was repeated for the next two months. By way of response, two 90mm guns were transferred to Cho-do from Kanghwa-do (a more peaceful guerrilla-controlled island northwest of Inchon) for use there as counterbattery fire against aggressive mainland batteries. The islands of Sok-to and Paengyong-do had likewise been bombed during this period, although no damage or serious casualties resulted. In December, enemy shore guns fired 752 rounds against Task Force 95 (United Nations Blockading and Escort Force) ships charged with responsibility for the island defense, in contrast to the 156 rounds of the preceding month.

Intelligence in December from “Leopard,” the friendly Korean guerrilla unit at Paengyong-do, also reported the presence of junks, rubber boats, and a nearby enemy artillery battalion off Chinnampo, believed to be in readiness to attack the island. A captured POW, moreover, on 22 December reported that elements of the 23d NKPA Brigade located on the mainland across from Sok-to would attempt to seize the island group before the end of the year. The next day, shortly after dusk, when a concentration of 200 rounds469 of 76mm suddenly fell on Sok-to, and another 125 rounds struck neighboring Cho-do, it looked as if it might be the beginning of trouble. Naval gunfire (NGF) spotters on the islands directed the fire from UNC patrol boats cruising the Yellow Sea. This counterbattery fire quickly silenced the enemy guns. Again, at the end of the month, West Coast islands were alerted for an invasion, but it never materialized.

A matter of continuing concern to the command during the fall and winter months was the North Korean refugee problem. So serious was the situation, in fact, that it had warranted a directive from the TF 95 commander (Rear Admiral John E. Gingrich). In the early fall, a large number of refugees had filtered into the West Coast Islands, raising serious doubts as to their feeding and ultimate survival during the Korean winter. Through the United Nations Civil Assistance Command, a tentative date of September had been set for evacuating these North Korean refugees to South Korea. By November the question of their relocation was still not settled, although the feeding problem had been eased somewhat by two LST-resupply loads of emergency rations and grain by CTF 90.

Activities followed a fairly consistent pattern during early 1953, with harassing fire striking the islands from the North Korean shore batteries and sporadic bomb and propaganda drops. Periodically USAF pilots who had strayed off course, planes from the nearby British carriers HMS Glory or Ocean, or Marine fliers from USS Badoeng Strait or Bataan made emergency landings on the beach airstrips at Paengyong-do for engine repairs or refueling. Logistical support continued to be a problem, due to the peculiarities of the joint ordering system through the Army. In January the western islands had unfilled requisitions dated from as early as February 1952. Official unit reports also noted the difficulty of obtaining medical supplies either promptly or in full.

In April, with the hot-cold cease-fire talks again taking one of their spasmodic upswings, WCIDU commander, Colonel Harry N. Shea, conferred with American and British naval officials regarding CTG 95.1’s (Royal Navy Commander, West Coast Blockading and Patrol Group) Operation PANDORA. This called for the evacuation of Sok-to and Cho-do, the two WCIDU islands north of the 38th Parallel, at the time of the armistice.

Increased naval gunfire and artillery missions against active enemy mainland targets, caves, and observation posts gave the two new 90mm guns delivered to the Sok-to garrison the month before and the pair already at Cho-do, as well as their gun crews, some unscheduled practice. Marine garrison personnel at the two islands and nearby patrol ships were busy 25 days of the month knocking out or neutralizing Communist mainside batteries. Late that month, the battleship USS New Jersey stationed off the east coast, sailed around the Korean peninsula to add its 16-inch guns to the bombardment. Enemy shelling of the two western islands increased in June, with 1,815 rounds expended in response by the two Marine gun sections.

During June, as it appeared the end of the war was in sight, the first phase of PANDORA got underway with the evacuation by CTF 95 of approximately 19,425 partisans, their families, and refugees from Sok-to and Cho-do to islands south of the 38th Parallel. A new WCIDU commander, Colonel Alexander B. Swenceski, had also arrived by this time, since the average tour of duty was but a brief four months at both island commands.

Across the Korean peninsula, the east coast Allied offshore island defense centered on a cluster of islands in Wonsan Harbor. Situated more than 100 miles north of the battleline, these strategically-placed islands comprised the northernmost UN-held territory in Korea. The East Coast Island Defense Command numbered approximately 35 Marines, 1,270 Korean Marines, and 15 Naval personnel. Headquarters for TU 95.2.3 was Yo-do, the largest installation, which was garrisoned by approximately 300 Korean Marines and a limited detachment of USMC and USN personnel. Smaller defense forces were located on the other islands under ECIDU command.470 In addition, an improvised NGF spotting team was also stationed at the three forward islands (Mo-do, Tae-do, and Hwangto-do). Mission of the ECIDU was a defensive one: to hold the islands as a base for covert intelligence activities. The island defense system existed for the purpose of “containing and destroying any enemy forces who escape detection or who press home an attack in the face of Navy attempts at their destruction.”471

Individual island commanders were responsible for the defense of their small parcels of seaborne real estate, control of both defensive and offensive NGF missions in the area, and evaluation of intelligence regarding enemy troop locations, the movement of supplies north, or new emplacements of hostile guns. Fire support for the ECIDU islands, exposed to the enemy shore batteries above the 39th Parallel, was available from Task Force 95, which maintained a task, group of ships off both the east and west coasts. Aircraft and ships of Task Force 77 (Seventh Fleet Striking Force), operating off the East Korean coastline, were also on call. In December, for instance, the Corsairs of TF 77 had resumed their rail-bridge interdiction. All-out attacks on railroad and highway bridges, as well as bombing runs on the 90-mile stretch of east coast railroad from Hungnam to Songjin, were undertaken to cut off supplies being moved north for Communist industrial use.

February marked the second anniversary of the siege of Wonsan by the UNC, the longest blockade of a port in recent U.S. history. Some naval authorities by this time argued that the venture had become one of doubtful merit which “should never have been undertaken, but its long history made it difficult to abandon without apparent admission of defeat.”472 In any event, the month also signaled increasing attention paid by hostile shore batteries to the little island enclave. For seven consecutive days, 9–15 February, the harbor islands were targets for enemy mixed artillery and mortar shells. Minor materiel damage and casualties were sustained at Yo-do during a Valentine’s Day bombardment, 14 February.

Altogether, the enemy harassed the harbor islands for 16 days during the month, expending 316 rounds, compared with 11 days in January. Hostile fire, not limited to the Wonsan Harbor islands, was also directed against friendly ships USS DeHaven and USS Moore. These provided counterbattery fire and were, in turn, fired upon, the nearest shells landing only 400 yards from the two vessels. This attack, also on 14 February, was described as an “unusually determined and precise”473 effort. The enemy, moreover, did not appear to take his usual precautions with respect to disclosing his positions. The fact that a Communist shore battery would cease fire when subjected to friendly counterbattery, with other positions then immediately taking up the delivery, “indicated some sort of central control for the first time.”474 The I Corps, NKPA artillery units across from the Wonsan Island command revealed the “heavy, effective artillery capability of enemy batteries which encircle Wonsan Harbor.”475

Unseasonably good weather the latter part of February improved the transportation and supply situation. With the bitter cold and wind subsiding, maintenance crews could repair the ravages of the past several months. Craft, up to LCVP size, were hoisted in on a large pontoon for repair. For most of December and January, “this small, physically remote Marine Corps command,”476 as the ECIDU commander, Lieutenant Colonel Robert D. Heinl, Jr. himself described it, had been snowbound. Winds howled in excess of 40 knots, and temperatures dropped to 10° below at night. Personnel at the command island, Yo-do, subsisted on C rations for eight days. With boating operations suspended because of the high winds, it was not possible to send supplies or water to Hwangto-do which for several days relied solely on melted snow.

The prolonged foul weather, moreover, interrupted all classified radio communications between the ECIDU and the outside world. Crypto guard for the Wonsan islands was maintained by elements of the East Coast TG 95. Coded and decoded security radio messages had to be picked up by patrol boat which could not reach the islands during extreme conditions of icy seas and heavy snows.

As with the men on the front line, the Communists stepped up their pressure and gunfire against the island command Marines during March. The record477 524 rounds which fell on the ECIDU islands in March doubled the following month when the command received 1,050 rounds from active mainland batteries. In April the persistent NKPA artillerymen kept up a continuing bombardment of the eastern coastal UNC islands, missing only three days of the entire month, that caused nine casualties when a direct hit was made on the Tae-do CP bunker. It was the highest rate of incoming since UN occupation of the islands. Another April record was enemy mine laying, which increased sharply in both the WCIDU and ECIDU command areas. A total of 37 mines were sighted, the highest number since August 1952. Communist shore gunners, in addition to harassment of the island themselves, fired 2,091 rounds against TF 95 ships, another all-time high.