Korea Series #2: CAS Defense at Pusan

Abstract: The opening months of the Korean War proved to be a failure for the United Nations and, more specifically, the United States. The Department of Defense over-prioritized strategic capabilities while neglecting the tactical partnership between air and ground that worked so well during WWII. Beginning with the September 1951 Joint Training Directive, US forces began to right the ship, reprioritizing tactical air power and joint fighting as they had in the European Theatre of WWII. They found success in this shift during the defense of the Pusan Perimeter, where the U.S. forces, aided by the USAF’s Tactical Air Control Party and subsequent close air support, successfully defended and then exploded out of the Pusan Perimeter.  

 

When the fighting started in Korea, General Stratemeyer’s Far East Air Forces (FEAF) contained ill-trained and ill-equipped TACP, a shell of a JOC that included zero participation from the Army side, and few aircraft to support the CAS mission.[1] These conditions point to the root cause of early failure in Korea: the United States was unprepared to fight a conventional war, which demanded the joint tactical fighting system employed by the Army and the AAF during WWII. After the early failures, leadership of all levels, including the Joint Chiefs of Staff, recognized the problem and sought to fix it through the Joint Training Directive for Air-Ground Operations (JTD).  

The JTD opened with a conflicting statement. It claimed to update the outdated doctrine of the 1946 FM 31-35, then followed by stating that “preparation has included study of WWII history and postwar recommendations of boards established to consider air-ground problems.”[2] The problem with that statement is that the 1946 edition of FM 31-35 was written immediately after the war by people who were in the heat of the joint fighting environment. Likely, this statement was just saving face; the introduction later stated (honestly) that doctrine for joint fighting existed but was not manned. This is an admission of the previously identified root cause of failure in Korea that joint fighting doctrine existed (in FM 31-35) but was not adhered to by either the Air Force or the Army.[3]

In all reality, the JTD updated little. Its importance came in the fact that it brought the importance of joint fighting to the limelight, and commanders quickly followed suit. For the Tactical Air Control Party, the JTD simply updated definitions and highlighted the primacy of TACP as the crucial link for the Army and Air Force at the tactical and operational levels. The first mention of TACP in the JTD reads, “A tactical air control Party usually is located in one of the forward armored vehicles and exercises direction of aircraft onto targets from this point of vantage. The column cover mission is of great assistance to armor in the exploitation of enemy disorganization and weakened resistance following a breakthrough.”[4] Furthermore, the JTD tweaked the definition of TACP, as seen below. [5]

 

The JTD also updated the methods for the TACP. 

 

            While the JTD was still being written, its priorities were being implemented at the front lines. In August, U.N. forces found themselves hunkered around the Pusan Perimeter. To bolster their defense in the hopes of blasting out of the perimeter, similar to how Bradley’s forces burst out of the Falaise Pocket of WWII, the Air Force prioritized pushing well-equipped TACP to the front lines and providing a feasible CAS platform for the fight. The solution for a CAS-capable aircraft came in the form of un-retiring the P-51 Mustang (redesignated the F-51).[6] As for the Army, they began furnishing their side of the JOC and committed to providing staff for joint planning.[7]

TACP at the Pusan Perimeter

 

The Pusan Perimeter, a roughly 50x100 mile box that UN Forces were confined to in the late summer/fall of 1950.[8]

 

         There were three significant engagements at the Pusan Perimeter, all of which TACPs played a critical role in. The TACP at the Naktong Bulge, Taegu, and Masan all employed similar tactics that, like WWII-style Armored Column Cover, blended close air support and interdiction. The lean toward a CAS/Interdiction mix came from the nature of the battlefield and the tools available, not from any doctrinal direction. After all, the TACP still had little training and understanding of doctrine when the battle for the Pusan Perimeter came.  

            The TACPs of the early Korean War consisted of six enlisted men, an Air Liaison Officer (ALO), and one dedicated T-6 “Mosquito” pilot for FAC(A) duties. The mobility and proliferation of T-6s, coupled with minimal North Korean air defense capabilities, led to a natural lean toward FAC operations. Not to mention, the ALOs were all pilots who preferred to fly rather than hang out on the ground playing infantry.[9] The TACPs at the corps and division levels functioned similarly to modern-day TACPs; they monitored and deconflicted fires and airspace, advised the ground force commander on the application of air power, and requested close air support missions.

            The Tactical Air Control System (TACS) developed organically, slightly outside of doctrine, during the first few months. Corps and culminated in a fairly smooth-functioning system at Pusan. division TACPs maintained functional HF communications with their front-line TACP, and the flow of aircraft to the front lines was effective, largely due to the added communications capabilities provided by the constant presence of a Mosquito overhead.  

            At Naktong Bulge, the KPA constantly attempted to cross the Naktong River near Yongsan, culminating in two major battles—the first on August 5—19 and the second on September 1-15. During the first battle, the 24^th Infantry Division was still recovering from its retreat South and lacked adequate food, water, and supplies for a full counterattack against the KPA incursion. To maintain the Perimeter, Generals Walker (8^th Army) and Partridge (5^th Air Force) focused reinforcements and air support on the 16-mile-long defense of the Naktong Bulge. In a joint effort that included 5^th Air Force TACP, F-51s, and F-80s, the Army’s 24^th and 25^th Infantry Divisions, and the 1^st Marine Provisional Brigade, UN Forces successfully defended the Naktong Bulge using CAS, artillery, and armor as their primary weapon.[10] By the end of the battle, the KPA 4^th Infantry Division had suffered a 50% combat loss, and the Mosquitos continued to pursue in retreat, directing F-51s and F-80s onto retreating targets.[11] The first battle at the Naktong Bulge proved to 5th Air Force leaders the value of centralized command and decentralized control, given the efficiency of coordinators (mostly TACP) from the JOC down to the front lines.   

A 5^th Air Force ALO (right) coordinates with a US Army armored battalion commander.[12]

            The CAS teams operated similarly at Taegu and Masan, both locations seeing sporadic action from August 5^th through September 19^th. The JOC routed aircraft to front-line TACP through HF channels, and coordination ran smoothly up and down the chain except for a few occasions that revealed some flaws in the system. The ROK divisions, which had already struggled up to that point, required hands-on aid from 5^th Air Force TACPs to coordinate American close air support in place of inadequate Korean CAS. When American TACPs were forced over to a Korean division, it exposed a huge problem for TACP on the peninsula – there weren’t enough of them.

            Each American Army division was only allocated 1-3 TACPs, and each division required a TACP dedicated to the command center for coordination. If a division only had one TACP, it would rely too heavily on the Mosquito FACs, who could then lose clarity on the friendly ground scheme of maneuver without a TACP on the front lines. When the situation demanded that TACPs also allocate to Korean divisions, they were spread so thin that the reliance on Mosquitos became overbearing for those FAC(A) pilots.

This problem led to intense political battles for the rest of the war and one that Air Force close air support’s most vocal critic, General Almond (X Corps commander), would highlight after his late September landings at Incheon. The Army was begging for TACP allocated down to every battalion, and the Air Force just didn’t have the capability to man that many TACPs.[13] Although the Army was about to pitch a political battle for control of the CAS mission, their leaders would also echo General Walker’s sentiment, who said, “I am willing to state that no commander had better air support than has been furnished by the 5th Air Force… I will gladly lay my cards on the table and say that had it not been for the air support we received from the 5th Air Force, we would not have been able to stay in Korea.”[14] The fact of the matter was that UN forces won the battle for the Pusan Perimeter and were poised for an explosive counterattack, largely thanks to close air support and the TACPs at the center of that close air support.