Forward air controllers in the Korean War were prominent throughout the conflict. United Nations forces depended upon improvised U.S. forward air control systems. The United States military held two competing doctrines for directing close air support (CAS). The U.S. Marine Corps' system depended on an organic supporting air wing delivering ordnance within 1,000 yards of front-line troops; this was to compensate for their weakness in artillery caused by being an amphibious force. On the other hand, the U.S. Army believed close air support should extend the range of its own organic artillery; it also wanted its own air corps. However, the U.S. Air Force was tasked with supplying trained fighter pilots as forward air controllers (FACs), with the Army supplying equipment and personnel. As events fell out, the 1st Marine Air Wing supplied the FACs and air strikes for X Corps during the war, while 5th Air Force supplied FACs and strike support to 8th Army. There were awkward attempts at coordination between the two, and with carrier-borne air power, though with limited success.
Tactical air power, including CAS, was largely instrumental in staunching communist offensives as the opposing forces swept back and forth in mobile warfare. (See graphic below.) Notable from the beginning was the reinvention of the airborne FAC; the T-6 "Mosquitos" of the 6147th Tactical Control Group would fly 40,354 FAC sorties, be credited with killing 184,808 communist troops, and win two U.S. and one Korean Presidential Unit Citations. Though only United Nations air superiority from the earliest days of the war made "Mosquito" operations possible, other FACs also inflicted serious casualties on the communists.
However, forward air control techniques paid off in diminishing returns once the opposing sides settled into trench warfare. As both sides dug in "à la" World War I, the communists operated at night to avoid air attacks. The U.S. Air Force FAC effort experimented with Shoran-directed raids and radar-directed bombing as a counter to this.
Even as the FAC systems served crucial roles in combat, the turf war concerning doctrine continued unabated. There were at least eight attempts to alter the Army/Air Force FAC system during the Korean War, with no substantive result. At war's end, forward air control policies in the U.S. military remained unchanged from those at its start. By 1956, the Army/Air Force CAS system was defunct.
Overview.
The U.S. military codified their forward air control (FAC) experience from World War II in 1946, when the most recent edition of Field Manual 31–35 "Air Ground Operations" (FM 31–35) was issued for the U.S. Army. The Army Air Force organized its strategic bombers into the Strategic Air Command (SAC), and split its fighters into Air Defense Command (ADC), and Tactical Air Command (TAC). The latter was tasked with close air support (CAS), and thus with forward air control. The Air Force's doctrine, based on Second World War experience called for three necessary conditions for successful close air support. One was gaining air superiority over the enemy. Another was isolating the battlefield via interdiction strikes on a foe's lines of communication. The third was the delivery of air strikes via a forward air control system supporting the Army's ground forces. The Army tended to believe the latter was given the lowest priority by the Air Force and resented it. In 1947, the newly established U.S. Air Force also adopted FM 31–35. However, this failed to set a single forward air control system within the U.S. military. As part of the division of forces when the Air Force became independent, the U.S. Navy and U.S. Marine Corps kept their aviation components and their forward control systems. The Army kept its light liaison aircraft and the few helicopters of the era, but was still dependent on the Air Force for most air support, including forward air control.
Background.
Two different forward air control systems had emerged during World War II. The U.S. Army and its Air Corps had developed one system in the North African Campaign; the U.S. Navy and Marine Corps developed a different system in the Pacific Theater. The U.S. Army fought a conventional land war in North Africa, using its tactical air power to strike beyond the range of its artillery. The U.S. Marine fought an amphibious war as light infantry supported by little artillery fire; consequently, they directed air strikes on targets within 1,000 yards of their own forces.
The newly independent Air Force concentrated on possible future nuclear warfare. In November 1948, Tactical Air Command was eliminated as a separate command within the Air Force. Much of the fledgling Air Force's energies were caught up in turf wars with other branches of the U.S. military. The U.S. Army was angling for its own organic air power within its ranks, "à la" the U.S. Marines. When the U.S. Navy and Marines pointed out the utility of air strikes landing as close as artillery fire to protect friendly troops, the Air Force countered that the Marines had to use air strikes because they lacked artillery in amphibious assaults. The Air Force pledged trained fighter pilots as forward air controllers (FACs) to direct a joint CAS operation; the Army was tasked with supplying radio equipment, vehicles, and personnel for these Tactical Air Control Parties (TACP). This led to another point of disagreement. The Army claimed it should have input into the types of aircraft used in close air support strikes, and plumped for propeller-driven planes; the Air Force claimed the right to develop its weaponry unimpeded, and intended to develop jets into CAS aircraft.
During the late 1940s, the U.S. military tested its forward air control capabilities per FM 31–35 during several joint field maneuvers involving the Army and Air Force. During the maneuvers, radios used for coordinating air action were unreliable; radio nets were overwhelmed with traffic. When the controllers could be contacted, they often had no targets to offer. When they did, they struggled to handle more than a single flight at a time. The early jet aircraft used for close air support had a voracious appetite for fuel, a short radii of action, and a short linger time over target. The joint Army/Air Force FAC effort results compared poorly to the U.S. Marines' organic system; it obviously needed drastic improvement.
Korea was an unpromising venue for an air campaign. A peninsula about a third larger than Florida, its terrain was characterized by a web of monotonous blue-green mountains interlaced with numerous valleys and ravines. The highest peaks formed a rugged spine that would divide military campaigns into coastal movements on either side of the mountains. Forward air controllers, with so many similar terrain features to observe, would find themselves tricked into errors of identification. To complicate matters, unreliable maps available bore widespread mistakes and confusions in town names, and portrayed terrain features as far as 1,000 meters out of true.
During World War II, the Japanese had built ten airstrips in South Korea, but only two could handle modern aircraft. Korean meteorology was also inimical to easy air operations. Because the weather fronts moved southward over North Korea into the war zone, the communists had the advantage of a figurative weather gage for their military planning.
The shooting war.
Retreat to the Pusan perimeter.
When North Korea invaded South Korea on 25 June 1950 to begin the Korean War, the only air control system in Korea was tasked to direct air to air combat. There were no forward air control units in Korea. The U.S. Air Force's only Tactical Air Control Group was in the U.S. So was the U.S. Army's 20th Signal Company, which was the only American unit capable of running an air communications network.
Nevertheless, two Air Force Tactical Air Control Parties arrived in theater within the war's first week. Over 60% of the air strikes flown in the first month of the war—some 3,251 sorties—beefed up the scanty artillery support of American and South Korean ground forces. American communication nets in Korea were so overloaded that close air support operations were hindered. At times, senior officers even desperately resorted to personal telephone calls to Japan to request air strikes. Without guidance, many tactical sorties became a hunt for targets of opportunity. Even B-29 Superfortresses were pressed into close air support, though with little effect.
General Partridge's solution for channeling air strike requests was to send SC-399 radios with operators to every Air Liaison Officer at an Army divisional headquarters, improvising an ad hoc air communications net that would eventually develop into the 6147th Tactical Control Group (6147th TCG) of airborne FACs. He also established a Joint Operations Center (JOC) on 5 July 1950, per doctrine. Meanwhile, on 14 July, the 6132d Tactical Air Control Group (Provisional) was formed as a ground FAC unit. On 23 July, it established a bare-bones Tactical Air Control Center without radar; it served as a radio net for the JOC, under the call sign "Mellow Control". It also assumed control of all TACPs in country. Liaison was established with the 1st Marine Aircraft Wing; any air strikes "excess" to support of marine ground units also were directed through "Mellow Control". In a cumbersome makeshift, naval aviation strikes had to be coordinated through U.S. Navy headquarters in Japan.
Despite being jury-rigged, the air control system played a great role in staving off American defeat in the first few months of the war. General William F. Dean said it was crucial in standing off the North Korean attacks. General William B. Kean told journalists after one hard-fought battle where his forces were supported by 108 sorties of tactical air, "The close air support strikes by the Fifth Air Force again saved this (25th) Division, as they have done many times before." General Walton Walker fervently agreed.
On 17, 19, and 20 July 1950, forward air controllers directed 5th Air Force fighter pilots in successful aerial interceptions that destroyed some of the last usable Yakovlev Yak-9s of the North Korean Air Force. With the North Korean air threat then roundly defeated, the United Nations established the superiority necessary for ongoing successful forward air control and close air support efforts.
During 1950, the 6147th Tactical Control Group operated as far as 50 miles into enemy territory, using relay aircraft to remain in radio contact.
Return of the airborne FAC.
Airborne forward air controllers merited a single dismissive sentence in FM 31–35. Nevertheless, two weeks into the war, Lieutenant Colonel Stanley P. Latiolas, operations officer of the Fifth Air Force, suggested having a slower airplane spot targets for the fuel-hog jets. Colonel John R. Murphy, familiar with the Horsefly FACs of World War II, asked General Earle E. Partridge for five pilots to fly reconnaissance. On 9 July 1950, Lieutenants James A. Bryant and Frank G. Mitchell flew the first airborne FAC missions of the Korean War from K-5 Taejon Air Base. They flew into K-5 with two Stinson L-5 Sentinels modified with needed VHF radios—which promptly became inoperable. Borrowing two 24th Division L-17 Navions, the lieutenants contacted surprised fighter pilots and directed about 10 flights of F-80s in air strikes.
The advent of airborne FACs was a timely one. The other four TACPs of the 620th Aircraft Control and Warning Squadron had joined its original two parties in ground forward air control as the U.S. military scrambled to form TACPs. Their utility was limited because the FAC had to remain with his MRC108 radio jeep while ordering air strikes, making a very visible target for enemy shellfire. The radios were fragile, and they were easily damaged by jolting and vibration. By 11 July 1950, only three of the radio jeeps were still working.
The following day saw the first use of a T-6 Texan for a FAC aircraft, as the original FACs flew a sortie directing air strikes by Lockheed P-80 Shooting Stars that knocked out 17 North Korean tanks near Chonui. During the direction of Royal Australian Air Force P-51 Mustangs, the T-6 radio became unserviceable. The FAC continued indicating targets by flying over them and rocking his wings. The resulting strikes were the first of many successful attacks made without radio contact, as United Nations bombers operated on many non-compatible radio frequencies. The T-6 became the standard FAC aircraft for Korean use, although others were considered.
Although the T-6 entered the FAC role as a "hot" aircraft, it was soon encumbered with numerous adaptations that degraded its performance. With a load that included