Marine Corps Role and Contributions to the Korean War: Ground, Air, Helicopter—FMF and Readiness Posture—Problems Peculiar to the Korean War—Korean Lessons

Marine Corps Role and Contribution to the Korean War: Ground691

Ground operations of the 1st Marine Division during the Korean War can be divided into six periods. These are the Pusan Perimeter defense (August-September 1950), Inchon-Seoul assault (September-October 1950), the Chosin Reservoir campaign (October-December 1950), East-Central Korea (January 1951-March 1952), West Korea (March 1952-July 1953), and the post-armistice period (July 1953-February 1955).

Marine Corps traditional concepts of readiness and fast, effective deployment were never better illustrated than in the hectic weeks following 25 June 1950. The NKPA invasion of South Korea came at a time when U.S. military forces were in the final stages of a cutback to peacetime size. Ships and planes were being “mothballed”; personnel of all the Armed Services were being reduced in number to the lowest possible effective manpower levels.

From the peak of its six-division, five-wing wartime strength of 475,600 in 1944–1945, the Marine Corps at the outbreak of the Korean emergency had only two skeletal divisions and two air wings. There were but 74,279 Marines on active duty, 97 percent of the Marine Corps authorized strength. Although a ceiling of 100,000 had been established for the Corps by law, it was a period of tight purse strings for all defense components. Fiscal austerity in the post-World War II period had whittled Corps numbers from 85,000 in FY 1947 to what was projected at 67,000 by the end of FY 1950.

This critically reduced strength found the normal Marine triangular infantry organization cut back to two companies per battalion, two battalions per regiment, and two regiments per division. The 1st Marine Division, at Camp Pendleton, and 2d Marine Division, at Camp Lejeune, were structured along the regular peacetime T/O of 10,232 USMC/USN vice the wartime minimum T/O of 22,355. No Marine units of any size were located in the Far East.

Despite its lean numbers in late June 1950, the Marine Corps once again would be in the forefront of American military response to the Communist aggression 6,000 miles across the Pacific. As hard-pressed South Korean forces and understrength U.S. occupation troops from Japan attempted to halt the Communist invaders, General of the Army Douglas MacArthur, on 2 July, requested the JCS to send immediately a Marine RCT with supporting air to the Far East. On 7 July, the 1st Provisional Marine Brigade was formed at Camp Pendleton from units of the 1st Division. Major components of the brigade—a balanced force of ground, service, and aviation elements—were the 5th Marines and MAG-33. Five days later, the 6,534-man brigade had mounted out from San Diego to answer the CinCFE plea for Marines to help turn the Communist tide engulfing Korea.

The brigade buttressed the faltering UNC defense in the Pusan Perimeter. Employed as a mobile reserve it helped prevent three enemy breakthroughs—at Chinju and the two Naktong River battles. On 7 August, a month after its activation, the brigade launched an attack toward Chinju. The Marine brigade was the first unit sent from CONUS to see combat in what was then considered a short-term police action. Later, in leading the way to destruction of an enemy bridgehead at the Naktong, the Marine brigade gave the defending Eighth Army its first victory against the NKPA in the Korean conflict.

Even before the brigade had been dispatched to the Far East, as the Korean situation continued to deteriorate, MacArthur had requested the JCS to expand the brigade to a full war-strength division. Between 10–21 July MacArthur, now CinCUNC, had made three separate requests for a Marine division. This persistence was reinforced by his growing determination to conduct a tactical amphibious operation to the rear of the overextended NKPA lines and thereby seize the initiative from the enemy.

In the States, meanwhile, authorization was received to bring the badly understrength 1st and 2d Marine Divisions up to full 22,000-man war levels. By stripping posts and stations, reassignment and rerouting of units, and callup of additional reserve personnel, major elements of the 1st Marine Division were on their way to Korea by mid-August. Timing was critical in order to meet the projected D-Day target date of 15 September.

Pulled out of the Pusan line on 12 September, the brigade was absorbed by the newly arrived 1st Marine Division in preparation for the coming Inchon invasion. As the brigade commander, Lieutenant General Edward A. Craig, USMC, later reminisced:

Organized as a unit less than four months, the brigade left behind it a reputation for mobility, effectiveness, and rapid deployment in the face of national emergency. Although Marine air and ground forces had operated together since 1919 in Haiti, formation of the 1st Provisional Marine Brigade “marked the first time that the air and ground elements, task organized under a single commander, had engaged in combat.”693

In the brilliant Inchon landing of 15 September 1950, Major General Oliver P. Smith’s 1st Division Marines led the X Corps attack in the first major counterstroke by United Nations forces on Communist-held territory. This maneuver was closely timed against enormous odds of personnel, logistics, and hydrography (tidal fluctuations of 31 feet) which made 15 September the only suitable assault date until mid-October. When outlined in earlier planning sessions by General MacArthur, the mammoth difficulties of the operation had been so unsettling that the designated Attack Force Commander for the landing, Rear Admiral James H. Doyle, expressed the view that “the best I can say is that Inchon is not impossible.”694

Despite all the difficulties, the landing at Inchon and recapture of Seoul, the South Korean Capital, and its adjacent Kimpo airfield by the Marines was a stunning tactical blow by the UNC that broke the backbone of the North Korean People’s Army 1950 offensive. The 1st Marine Division, in its successfully executed amphibious landing, had offered UNC forces an opportunity to defeat the enemy decisively before a Siberian-like Korean winter set in. Accomplished under the most adverse weather and geographic conditions, the assault proved anew the decisive power of amphibious forces employed at a critical time and place. This capability and readiness of the Marine Corps had totally reversed the military situation, and a battered enemy was on the run. The subsequent routing of the NKPA divisions in the Inchon-Seoul campaign by X Corps and the Eighth U.S. Army forces would have led to an early UN victory had not the Chinese Communists intervened to support their Korean counterparts. The operation had validated Far East Commander General MacArthur’s early premise that:

The Inchon operation, moreover, had been planned in record time—approximately 20 days. This was one of the shortest periods ever allotted to a major amphibious assault, involving the planning, assembly of shipping, and mounting out of a combined force of 29,000 Marines and support personnel.

With the Inchon-Seoul operation ended, the 1st Marine Division (including the 7th Marines which had reached Inchon in time for the liberation of Seoul) reembarked on 12 October for deployment to the east coast of Korea. A new military operation was envisioned north of the 38th Parallel against Pyongyang, the North Korean Capital. As part of the drive, X Corps was to make an amphibious envelopment on the east coast, in the area of the enemy-held port of Wonsan. From here X Corps would advance westward toward Pyongyang, to link up with Eighth Army troops and trap NKPA forces withdrawing from the south.

While the Marines were en route to the objective, word was received that ROK troops had overrun Wonsan and were pushing north. The revised X Corps plan of operation called for a three-pronged attack towards the Yalu. The Marine division would advance on the left, the U.S. Army 7th Division in the center, and 1st ROK Division on the right flank. This drive to the north and subsequent action at the Chosin Reservoir would rank as one of the most rigorous campaigns in the entire history of the Marine Corps.

Fighting as part of EUSAK, by this time fanned out throughout North Korea, the 1st Marine Division did not meet the expected NKPA resistance. Instead, large-scale Chinese Communist Forces had entered the war. As X Corps swept north toward the Yalu River in November 1950, the Marines became the first United States troops to defeat the Chinese Communists in battle. At Sudong, after four days of savage fighting, the Marine RCT-7 so badly crippled major elements of the 124th CCF Division that it was never again committed as an organic unit.

When the Chinese forces struck in full force at the Chosin Reservoir, X Corps units were forced back. Elements of a nine-division assault force, the CCF 9th Army Group, which had been sent into Korea with the specific mission of annihilating the 1st Marine Division, began to attack. On 27 November, the Chinese directed a massive frontal assault against 5th and 7th Marines positions at Yudam-ni, west of the reservoir. Another CCF division, moving up from the south, cut the MSR held by the 1st Marines so that the division at Yudam-ni, west of the reservoir, was completely encircled by Communist forces. Many experts considered the 1st Marine Division as lost. Others thought the only way to save it was to airlift it out, leaving its equipment behind. Instead, the Marines seized the initiative at Yudam-ni and cut a path through CCF units blocking a route to Hagaru. The division battled its way out in 20-degree-below-zero weather 78 miles over icy, winding mountain roads from the reservoir to the Hamhung-Hungnam area where, on 15 December, it redeployed to South Korea.

Integrated ground and air action enabled the 10,000 Marines and attached 4,000 Army-Royal Marine troops to break out of the entrapment and move south. During 13 tortuous days the Marines had withstood hostile strength representing elements of six to eight CCF divisions. The major result, from the military view, was that the Marine division properly evacuated its dead and wounded, brought out all operable equipment, and completed the retrograde movement with tactical integrity.

Not only had the Chinese (with a total of 60,000 men in assault or reserve) failed to accomplish their mission, destruction of the division, but the Marine defenders had dealt a savage blow to the enemy in return. POW debriefings later revealed that assault units of the CCF 9th Army Group had been rendered so militarily ineffective that nearly three months were required for its replacement, re-equipment, and reorganization.

Early in 1951, the 1st Marine Division was reassigned to IX Corps for Operation KILLER, a limited offensive ordered by the EUSAK Commander, General Matthew B. Ridgway. In Operation RIPPER, in March, the division led another IX Corps advance as it drove toward the 38th Parallel on the east-central front. When the Chinese struck back with their spring offensive on 22 April, the Marines were transferred to operational control of X Corps and counterattacked to restore the UNC defensive position in the far eastern sector. During May and June, the 1st Marine Division continued to punish the enemy in the Punchbowl area of eastern Korea, driving the CCF back to Yanggu and the Soyang River corridor.

Activity all along the UNC front came to an uncertain halt in July 1951 when Allied and Communist negotiators met at Kaesong for truce talks initiated by the enemy. In August the MLR flared into action again, and the Marine Division was engaged in new counterthrusts in the Punchbowl area. Fighting during the next three weeks involved the division in some of its hardest offensive operations in Korea. It also developed that this would be the last offensive for the Marines. In November 1951, as a result of the truce talks and possibility of ending hostilities, General Ridgway, now UNC Commander, ordered the Eighth Army to cease offensive operations and begin an active defense of the front.

The war of fire and movement had turned into one of positional warfare, a defensive posture by UN forces that would continue for the last 21 months of the three-year conflict. Throughout the winter of 1951–1952, the Marines conducted vigorous patrol activities in their sector of X Corps. Although it was a lackluster period of trench warfare for the average infantryman, major tactical innovations were being pioneered by the division with its use of the transport helicopter for logistical and resupply missions.

In March 1952, the 1st Marine Division was transferred from the eastern X Corps line 140 miles west to strengthen the far end of the Eighth Army MLR in the I Corps sector. The division was relocated in the path of the enemy’s invasion route to Seoul, where weak defenses in the Kimpo coastal area had threatened the security of the UNC front. Here the division’s four infantry regiments (including the 1st Korean Marine Corps RCT) held nearly 35 miles of front line in the critical Panmunjom-Munsan area. The demilitarized route for the United Nations negotiators led through the Marine lines. It was the most active sector of the UN front for the next 16 months. This key position guarded the best routes of advance from North Korea to Seoul and indicated the high regard in which General James A. Van Fleet, EUSAK commander, held the Marines.

West Korean terrain was rugged, hilly, and friendly to the CCF who had the advantage of high ground positions as well as considerably more manpower. Although cast in an unaccustomed defensive warfare role, rather than a true attack mission, the Marines repelled an almost continuous series of enemy probes. While truce talks went on at nearby Panmunjom, fighting as furious as at any time earlier in the war flared up intermittently as the CCF tried to gain additional terrain for bargaining purposes. During 1952–1953, the Marine division beat off determined CCF limited objective attacks on Bunker Hill, the Hook, Vegas, and Boulder City outposts up until—literally—the final day of the war, 27 July 1953.

In reviewing Marine actions during this period, the Secretary of the Navy commented:

This type of prolonged static warfare gave little real satisfaction to Marines accustomed to waging a war of movement and a more tangible “mission accomplished.” The year of positional warfare in western Korea was costly, too. Total U.S. casualties in the Korean War numbered approximately 137,000 men killed, missing, or wounded. The Marine Corps toll was 30,544. Of this number, 4,262 were KIA, an additional 244 were listed as non-battle deaths, and 26,038 were wounded. During this last part of the war, Marine casualties (both ground and air) totaled 13,087, plus an additional 2,529 for the attached 1st KMC/RCT. Astonishingly, 1,586 Marines or 39.6 percent697 of the infantry Marines killed in the entire war were victims of the “static,” outpost warfare in the west. Another 11,244 were listed WIA during this period—representing 43.9 percent of the total number of ground Marines wounded during the three years of conflict.

Conditions varied widely during the 1950–1952 and 1952–1953 periods of the war. The enemy’s improved capability in artillery during the latter period of positional warfare largely accounts for the high casualty rate at this time. It has been noted that:

It might be valid to question the use of Marine Corps specialists in amphibious warfare in an Army-type conventional land war. The protracted land campaign that characterized the latter stages of the Korean conflict actually was waged for the majority of the war period—from September 1951 to July 1953, or nearly two years. In terms of economy of manpower it could be considered an inefficient, though not ineffective use of Marines. On the other hand, the history of warfare down through the ages makes it repeatedly clear that a nation fights the pitched battle against its opponent with the arsenal of weapons and personnel at hand.

As an Eighth U.S. Army component (attached variously to the X, IX, and I Corps), the 1st Marine Division (one of nearly 20 divisions representing U.S. Army, British Commonwealth, and ROK troops) performed its assigned mission—to repulse and punish the enemy. It contributed heavily to maintaining the integrity of the EUSAK front and was considered one of the two crack EUSAK divisions—the other being the Marines’ neighbor to the right, the British Commonwealth Division. With the attached KMCs, the 1st Marine Division, moreover, was also the biggest and strongest division in EUSAK.

Most importantly, fast deployment of the Marine division had made possible the brilliant tactical maneuver at Inchon. Many military experts, following World War II, had envisioned future conflicts only in terms of atomic warfare and massive strategic air assaults. Even the Chairman of the Joint Chiefs of Staff “had predicted publicly, hardly six months before, that the world would never again see a large-scale amphibious landing.”699 In contradiction to new atomic-age tactics, however, the United Nations commander in September 1950 had turned the tide of the battle by his use of a conventional maneuver—envelopment by amphibious assault. The performance of the Marine Corps was thus responsible, in part, for changing post-Korean War military doctrine from total reliance on new tactics and weaponry to a more balanced concept that combined both sophisticated innovations and viable, established procedures.

Although unemployed in its primary amphibious role after late 1950, the 1st Marine Division had originally been positioned on the eastern front because of this capability. It was the UN commander’s desire to have EUSAK’s only amphibious trained and equipped division near the coast in the event that an amphibious maneuver was required for offensive or defensive purposes. Again, in the division’s 1952 move to the western coastal front in the Kimpo area, this fighting capability was a major consideration.

To a large extent, U.S. forces in Korea fought the early part of the Korean War with weapons from the preceding war—only five years removed. Three tactical innovations employed by the Marine Corps during the Korean War were highly successful and largely adopted by the other services. These were the thermal boot, individual body armor, and the helicopter. All were first combat tested in 1951.

Frostbite casualties during the first winter in Korea resulting from inadequate footwear made it necessary to provide combat troops with specially insulated footgear. The new thermal boot virtually eliminated frostbite for both Marine infantrymen and aviators. Armored utility jackets had been developed toward the end of World War II but were not actually battle tested. The Marine Corps had renewed the experimentation in 1947. First combat use of the plastic, light-weight body armor was made in July 1951 by Marines while fighting in the Punchbowl and Inje areas of X Corps. Improvements were made to the prototypes and by the following summer the Marine Corps, following a request made by the Army Quartermaster General, furnished some 4,000 vests to frontline Army troops. By 1953 the 1st Marine Division had received its authorized quota of 24,000 vests and new lower torso body armor had also been put into production.

Medical experts reported that the effectiveness of enemy low-velocity missile weapons striking a man wearing body armor was reduced from 30–80 percent. Chest and abdominal wounds decreased from 90–95 percent after issuance of the armored vests. Overall battle casualties were estimated to have been cut by 30 percent. By the time of the cease-fire, the protection offered by the Marine body armor had been extended to some 93,000 Marine and Army wearers. Hardly anywhere could the U.S. taxpayer or fighting man have found a better buy for the money: mass production had reduced the per unit cost of the Marine armored vest to just $37.50.

Air700

On 3 August 1950, eight VMF-214 Corsairs led by squadron executive officer, Major Robert P. Keller, catapulted from the deck of the USS Sicily to launch the first Marine air strikes in the Korean action. From then until 27 July 1953, units of the 1st Marine Aircraft Wing flew 127,496 combat sorties in the Korean War, considerably in excess of the 80,000-odd sorties for all Marine aviation during World War II. Of this Korean number nearly a third, more than 39,500, represented the Marine Corps close air support specialty, even though 1st MAW pilots were heavily engaged in other assignments from Fifth Air Force. These included interdiction, general support, air defense patrols, air rescue operations, photo and armed reconnaissance, and related tasks to insure Allied air superiority.

With the outbreak of Korean hostilities, Stateside Marine air units were alerted for combat duty by 5 July. At Major General Field Harris’ 1st MAW headquarters, El Toro, MAG-33 elements were quickly readied for deployment to Japanese bases and thence to Korea. Commanded by Brigadier General Thomas J. Cushman, MAG-33 comprised Headquarters and Service Squadron 33, fighter squadrons VMF-214 and -323, an echelon of nightfighters from VMF(N)-513, two radar units (Marine Ground Control Intercept Squadron 1 and Marine Tactical Air Control Squadron 2), plus the observation squadron, VMO-6. Forward elements were quickly on their way, arriving in Japan on 19 July, while the rear echelon reached the Korean Theater on 31 July. Twenty R5Ds from Marine Transport Squadrons 152 and 352 were already providing logistical support for Pacific lift operations.

After practicing some last minute carrier landing approaches, the fighter pilots got into combat almost at once. Following -214 into the war, VMF-323 started operations on 6 August, flying from USS Badoeng Strait in support of the Pusan ground defenders. When the brigade mounted out on 7 August on its drive to Chinju, the two MAG-33 carrier squadrons were there with their 5-inch HVARs, napalm, 100- to 500-pound bombs, and 20mm cannon. VMF(N)-513 began its regularly-scheduled night tours over the Korean perimeter that same date, lashing at enemy supply and transportation centers in the Sachon-Chinju area of southern Korea. VMO-6 had already started evacuating casualties from the Pusan area three days earlier.

Many Army ground commanders witnessed the Marine system of close air support for the first time during the Pusan fighting. After the second Naktong battle, when air strikes had silenced enemy guns and 300 troops near Obong-ni, the commander of the 23rd Regiment to the right of the brigade wrote General Ridgway in Washington:

And while Marine, Army, and Navy staffs were completing plans for the forthcoming Inchon assault, MAG-33’s little aerial Photo Unit (part of Headquarters Squadron) took a series of reconnaissance photographs of the landing beaches in preparation for the closely coordinated maneuver.

During Inchon-Seoul operations, MAG-33 was joined by three MAG-12 fighter squadrons: VMF-212, VMF-312, and VMF(N)-542. After the capture of Kimpo airfield, 212’s “Devilcats” and 542’s nightfighters transferred from Itami to Kimpo. Flying out of 2d MAW headquarters, Cherry Point, N.C., on 18 August, the Devilcats had climaxed a hurried dash halfway around the world to get into action. The squadron flew its first combat mission from Kimpo a month after its departure from the East Coast. While the MAG-12 land-based squadrons and the carrier pilots functioned as the division’s flying artillery, MGCIS-1 set up a radar warning system and MTACS-2 established a Tactical Air Direction Center to direct all aircraft in the X Corps zone of action.

With the conclusion of the Inchon operation on 8 October, VMF-312 and VMF(N)-542 remained at Kimpo. Other Marine squadrons (VMF-212, VMF(N)-513, VMO-6, HqSq-12, and carrier-based VMF-323) shifted to the Korean east coast in readiness for the Wonsan landing and subsequent deployment north of the Marine infantry regiments. Wing elements began arriving at the port city’s airfield on 13 October. Division Marines, meanwhile, on board ship in the Wonsan harbor while more than 3,000 expertly laid Communist mines were being removed, did not land until 26 October. For the men who fought the vertical war in Korea, it was “one of the rare times in the air-ground association, the 1st MAW had landed ahead of the 1st Marine Division. The aviators didn’t miss putting up a big sign-board “Welcome, 1st Division!”702

As 30 CCF divisions slammed into UNC forces all across the fighting front in late November to change the nature of ground operations (and the future of the war), so did the onset of the first Korean winter test 1st MAW aerial skills and ingenuity. Low hanging ceilings, icing conditions, and three-inch snows on the carrier decks were common operating hazards. For the shore-based pilots, the bad weather often caused changed flight plans as they were forced to land at alternate fields or on Navy carriers. Nonetheless, Marine RD4s flew up to the southern tip of the Chosin Reservoir, at Hagaru, to air-drop ammunition and supplies and evacuate casualties from the entrapment. Logistical support to this tiny frozen makeshift air strip was also provided by Air Force C-47s and C-119s. Later on, during the first step of the grinding movement south, Air Force pilots paradropped a sectionalized steel bridge vitally needed at Koto-ri to replace a destroyed span over a chasm.

Beginning with the load-out for Wonsan in early October, the 1st MAW was placed under operational control of the Seoul-based Fifth Air Force.703 Echelons of FAF air command and control initially slowed operational orders anywhere from 4 to 36 hours. Simplified interservice communications and command liaison between 1st MAW and FAF helped improve the situation. With a verbal agreement, on 1 December, for CG, 1st MAW to receive full control over X Corps area aircraft, problems eased substantially. To a large degree the close coordination of Marine aviation and ground forces during the Chosin campaign was due to the use of flexible, simplified, and fast battle-tested Marine Corps-Navy CAS techniques and to having increased the number of pilot FACs from one to two per battalion.

The Marine movement south from Hagaru was protected by one of the greatest concentrations of aircraft during the entire war. Twenty-four CAS aircraft covered the breakout column, while attack planes assaulted enemy forces in adjacent ridge approaches. Marine planes on station at Yonpo (south of the Hamhung-Hungnam axis) and carrier-based VMF-323 flew some 130 sorties daily. Another 100 attack sorties were flown daily by Navy carrier-based planes, while FAF flew interdiction missions beyond the bombline. Marine Panther jets of VMF-311, operating with the Air Force from the Pusan area, got into the action at Yonpo. It was also at this time that an airborne TADC (tactical air direction center) was first improvised when the radio jeeps moving south with the column had communication failures. For six days, a VMR-152 R5D transport orbited 2,000 to 4,000 feet above the Marine units to control air support between Hagaru and Chinhung-ni as a flying radio nerve center.

From late November to early December, as the division battled its way from Chosin to Hamhung, Marine, Navy, and Air Force aircraft evacuated more than 5,000 Marine, Army, and ROK casualties. And during the most critical period, the little OY spotter planes and HO3S-1 helicopters from VMO-6 provided the only physical contact between units separated by enemy action. Marine tactical squadrons in these three early major offensives of the war, from 3 August to 14 December, flew 7,822 sorties, 5,305 of them CAS for the battered UNC ground units.

From 1951–1953, 1st MAW pilots and planes came under direct control of FAF. They alternated between principal missions of interdiction raids to harass and destroy Communist supply lines north of the battlefront, general support sorties outside the bombline, and CAS flights to support infantry forces threatened by enemy penetration. Typical of FAF focus on massive aerial assaults were the following assignments that Marine flyers participated in:

Operation STRANGLE, a major Fifth Air Force all-out interdiction effort to cripple the enemy supply life line, was undertaken 20 May. When the Chinese Communist spring offensive broke shortly thereafter, MAG-12 Corsairs and -33 Panther jets delivered maximum support to the MLR regiments, the 1st and 7th Marines. When the truce talks began in Kaesong, in July 1951, 1st MAW planes and the radar searches of MACG-2 stood guard. Batteries of the Marine 1st 90mm AAA Gun Battalion, attached to the wing, were also alerted to keep under surveillance the approaches to key military ports.

New tactical developments pioneered by 1st MAW during the Korean War advanced the UNC air effort and added to the 1st MAW reputation for versatility. Several major steps forward were taken toward Marine aviation’s primary goal of providing real operational 24-hour CAS, regardless of foul weather conditions. The new MPQ-14 radar-controlled bombing equipment, developed between 1946 and 1950, was employed by MASRT-1, as a device to control night fighter sorties of a general support nature flown by day attack aircraft. By means of height-finding and directional radars, it enabled a pilot to leave his base, drop a bomb load on target, and return to home field without ever having seen the ground. It offered major practical improvement in blind bombing methods. MPQ was limited, however, in its use in sudden, moving battle situations because of some of its sophisticated, hand-built ABC components. A real tactical breakthrough in night CAS came in April 1953 when VMF(N)-513 and the VMO-6 spotter planes evolved the new searchlight beam control system which made possible 24-hour coverage for 1st Marine Division ground units.

In other innovations, it will be remembered that the Air Force in late 1952 had requested escort by VMF(N)-513’s new two-place jet-intruder F3D Skyknights on Air Force B-29 night bombing missions. During a four-month period from 1952–1953, the Marine night fighters downed one enemy plane or more a month while escorting the B-29s. Once the F3Ds began their night escort role, Air Force bomber losses became negligible.

A unique capability of the long-range, jet-intruder night-fighter was that the F3D carried a radar operator who replaced the ground controller, thereby extending air-defense radar range to the aircraft. It could thus operate independently and effectively at great distance from its base. Without GCI (ground control intercept) aid, VMF(N)-513 direct escort to bombers at night was so successful that the squadron’s planes were used as exclusive escort of the Bomber Command B-29s. In November 1952, the Marine squadron’s two night kills were the first ever recorded by airborne intercept radar-equipped jet fighters. At the end of the war, Skyknights and -513 pilots (flying F3Ds as well as the earlier F7Fs) had destroyed more enemy aircraft than any other Marine or Navy day or night fighter plane. Tactics employed by VMF(N)-513 were original in concept and required a high-level of training and individual pilot-AIO (airborne intercept operator) proficiency. It was noted that:

An operation somewhat in reverse of the nightfighters was that of VMJ-1, the Marine photographic squadron, which had its own Air Force escort. Formerly the Wing Photo Unit, VMJ-1 was commissioned in February 1952 and flew a total of 5,025 combat flights. Under FAF operational control until late in the war, the squadron’s 550-mph F2H-2P twin-jet Banshees flew unarmed deep into enemy country—even as far as the MIG-guarded Yalu—photographing positions, airfields, power plants, and other targets. An escort plane flew cover while the photo ship took pictures. Photo missions to the Suiho Reservoir were rated so important that “24 Air Force F-86 jets flew an umbrella.”705 Introduction of the squadron’s jet Banshee early in 1952 was a major step in improved aerial photography. The Banshee was the superior photographic aircraft in the combat theater, because of its new advanced-design view finder and operating range.

Coverage from VMJ-1’s gross wartime output of 793,012 feet of processed prints was equal to a continuous photographic strip six and half times around the earth at the equator. The Marine photo squadron contributed a third to the entire UN photo reconnaissance effort and at times flew as much as 50 percent of all FAF intelligence missions.

Throughout the war the four attack squadrons of MAG-12 (VMAs-212, -251, -121; and -332 at the end of the war) had dumped seemingly endless bomb loads on CCF installations, while MAG-33’s two jet-fighter squadrons (VMF-115 and -311) had provided the Marine exchange pilots who scoured the lower side of the Yalu with the Air Force F-86s on fighter sweeps.

During Korea the Marine CVE/CVL squadrons (VMAs-214, -233, -312, and -251) flew more than 25,000 sorties, experimenting with improved techniques for carrier landings. The carrier qualification program of Marine air units, a regular part of their training, also proved its value in combat. In the earliest days of the war, VMF-214 and -323706 had operated from two CVEs based off the south coast of Korea, thereby providing close support to the brigade and other Eighth Army elements at a time when all shore-based aircraft were forced to operate from Japan.