Airborne Operations [2-3.7 AC.F] - TAB G
U.S. AIRMOBILE OPERATIONS IN VIETNAM, 1962-65
Until the fall of 1961, the Republic of Vietnam (RVN) had only a very limited capability for airborne operations (one helicopter squadron and two transport squadrons) and no training in the techniques of airmobile operations. In November 1961, in line with President Kennedy's decisions to prevent Communist domination of Vietnam, the U.S. Army assumed the mission of helping the RVN armed forces increase their airlift and air mobility capabilities.
Under existing national policy, the Army at first could neither deploy armed helicopter units to Vietnam nor overtly participate in counterinsurgency operations. Training Vietnamese in helicopter operations and tactics, though considered, would have been too complicated and time consuming. During November 1961, the JCS directed the deployment of three Transportation Companies (Light Helicopter) equipped with CH-21's to the RVN. By the end of January 1962 the companies had arrived and by 15 April had been augmented by a Marine helicopter squadron. Their mission was to "expedite combat operations by providing direct tactical and logistical air transport to [RVN] combat units," in other words, to fly support missions for the RVN armed forces, since Vietnamese pilots were not yet qualified, and to assist in training activities. The helicopter units were followed in February by the first fixed wing aircraft units.
Within little more than a month, after 540 combat support sorties, it appeared that U.S. efforts were off to a good start. A quick strike capability, which had been lacking, could now be provided, but it appeared
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that, because of the large area to be covered, the number of helicopter companies was inadequate. Indeed, each of the seven RVN divisions would need one helicopter company of its own. The estimated monthly requirement was 820 sorties. Since the CH-21 helicopter was outdated there was a need for more modern equipment such as the UH series of helicopters. But early in 1962, the Army did not have the equipment. Not until 1964, were all CH-21's replaced by UH-1B's. During this period, the helicopter transport companies were converted to airmobile companies that fitted more adequately the requirements of the ROAD divisions and the situation in the RVN. Solved also during this period, were the initially very considerable logistical and support problems attending the deployment on a crash basis of what amounted to 10 percent of U.S. Army aviation assets.
The type of operations of U.S. Army helicopter companies initially varied due to differences in terrain, weather, and the type of military mission. In the northern (I Corps) area, the helicopter company was engaged chiefly in small-scale resupply to numerous outposts. In central RVN (II Corps) resupply missions far outnumbered the few airmobile operations that were undertaken. Only in the larger Delta area (III Corps [sic]), were helicopters extensively employed in combined airmobile operations with troop lifts ranging from company to battalion size. The results were rather meager. More often than not, the RVN units failed to trap the Viet Cong (VC); they merely captured or destroyed weapons, materiel, and installations. Although more than 100 RVN companies were trained in airmobile operations, their responses were often sluggish, and almost always intelligence proved to be faulty. Much still had to be learned
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in how airmobile operations—which depend on accurate and timely intelligence, prompt and reliable communications systems, and surprise—were to be conducted.
The need for more helicopter companies was filled by September 1962, when two additional companies arrived in RVN, raising the total to 6 (including the Marine Squadron). By then it had become apparent that the CH-21 transports had to be protected against enemy action. The Army concluded that armed escort helicopters could provide the protection and do it better than fixed wing aircraft could. By early October, an Army Utility Tactical Transport Company (UTT) equipped with UH-1A armed helicopters arrived at Saigon. The UH-1A's were replaced by faster and more powerful UH-1B's as soon as the Cuban crisis had passed. By January 1963, 222 U.S. Army aircraft were in Vietnam (149 helicopters). They had flown 57,197 sorties and had transported 4,759 tons of cargo and 251,938 passengers in 47,600 fly hours.
These operations had provided the first hard test for airmobile doctrines under combat conditions, concepts and tactics that had been developed as early as 1956. The doctrine was that heliborne maneuver forces operating beyond the range of friendly ground fire support needed to be armed to accomplish their mission. Since helicopters had proved to be most vulnerable during landing and take-off, they required a defensive fire capability and means to level suppressive fires against enemy action. The Army doctrine stressed the importance of speed, surprise, and firepower in helicopter combat operations. In a typical airmobile operation, the assault force was to approach its objective along preplanned routes, avoiding enemy concentrations of antiaircraft weapons not destroyed in prestrike missions.
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Troop-carrying helicopter formations were to be escorted by armed high-performance helicopters, which would provide the needed suppressive [sic] fires enroute and in the objective area. To reduce chances of being detected, contour flying was to be used. Air Force was to provide additional air cover if needed. The Army had also developed weapons systems—for example machine guns and rockets—and gunnery techniques of equal or better accuracy than those used in fixed wing aircraft. Thus, before the doctrines and techniques were put to the test in Vietnam, the Army had concluded that helicopters could operated in a combat environment if suppressive fires were provided.
In airmobile operations in Vietnam, helicopters had to take additional protective measures: deception as to approach routes to the target, protection of crews and aircraft (self-sealing fuel tanks, body armor, and armor for vital aircraft parts), armament (door-mounted weapons), armed escort helicopters (to neutralize enemy forces), and rescue procedures for disabled aircraft.
After one year of operations it was found that, to avoid gun fire, formations should fly at 1,500-2,000 feet instead of close to the ground. Contour flying was practiced in the jungle of the highlands region. Transports also needed 5-7 escorts, instead of 3 as anticipated, and the interval between an advance guard and the main force should be only 15-30 seconds—time sufficient to divert the transports in case of heavy opposition.
The chief factors hampering airmobile operations in Vietnam in 1962 were: unfamiliarity of RVN commanders and forces (and their MAAG advisors)
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with this type operation; inadequate maps and navigation aids; MACV's (Military Assistance Command, Vietnam) tendency to overcentralize control; and restrictions regarding the rules of engagement. For example, not until February 1963 were armed helicopters allowed to engage clearly identified enemy targets threatening the safety of helicopters. Most serious was the sharp drop in the availability rates of helicopters, from 73 percent before June 1962 to 23 percent in January 1963. (By 1964 availability rates climbed back to about 80 percent.) The limited availability was attributed to the climate, enemy action, spare parts' shortages, lack of maintenance facilities, and slow requisitioning procedures. The Army gradually overcame these difficulties by establishing a special "Project Air Vietnam" in November 1962.
In spite of the many problems encountered during the first year of operations, Army aviation made a vital contribution to RVN offensive and logistical support operations, and gained invaluable combat experience in counterinsurgency operations.
The year 1963 opened with the battle of Ap Bac. This much-publicized combined arms operation, in which airmobile and airborne forces were employed in key roles, was supposed to destroy a hardcore VC battalion. It failed, though it provided some valuable lessons: the helicopter troop lift was successful; the heavy losses in aircraft occurred largely because of persistence in automatically attempting to rescue downed crews; an air strike before the operation would have helped; surprise was compromised; better co-ordination between rotary and fixed wing aircraft and better air-ground communications were needed; tactics of escort helicopters had to be
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refined especially with regard to techniques for sustained defense of the landing zone; and, an increase in the armament of the UH-1's appeared necessary.
During 1963 the Army substantially improved its aviation establishment, doubling the total number of aviation units (helicopter companies rose to 7), replacing outdated equipment and converting the light helicopter transport companies to airmobile companies, and refining tactics, techniques, control, and organization. In February, 1963 the restrictive rules of engagement were eased to the extent that armed helicopters could engage clearly identified enemy targets that posed a threat to the safety of helicopters and passengers; and flights close to, but not across the Laotian and Cambodian borders, hitherto prohibited, were permitted. Tactical and technical improvements were achieved in the areas of reconnaissance, configuration of flight formations approaching landing zones, armed escort procedures (first escort flights occurred in May), command and control (airmobile command post), and weapons and equipment.
A variation of the standard airmobile operation was the "Eagle Flight." The new operational concept employed a formation of armed and unarmed ships—typically 3 escorts and 4 troop carriers—with each carrier transporting a 10-man rifle squad. Eagle Flights might reinforce an earlier established operation, seal a gap, capture or destroy escaping VC, make a raid, or undertake a mission of armed reconnaissance. The success of Eagle Flights depended on surprise, an available landing zone, quick reaction. They were most successful in the Delta area.
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The Viet Cong countered the Eagle Flight and other airmobile threats to their operations by improving their defenses. They acquired better and heavier weapons, more effective ammunition, improved their training, and gained experience. This trend, combined with the increased rate of sorties, which almost quadrupled from 57,197 in 1962 to 231,900 during 1963 (an average of 60 percent were helicopter sorties), exposed U.S. aircraft and crews far more to enemy fire than in 1962. While only 5 aircraft (4 helicopters) were hit by ground fire in 1962, 878 (623 helicopters) suffered that fate in 1963; 36 aircraft were downed and 12 of these destroyed. MACV attributed the losses to "increasingly accurate VC ground fire." Nevertheless, the RVN held the initiative and the accent for airmobile operations was on the offensive.
In 1964 the picture began to change. In spite of another substantial increase in U.S. Army aviation units (to 9 airmobile companies [UH-1B]), planes (to 512—325 of them helicopters), aviation personnel (to 5,106, equal to 34 percent of U.S. Army strength in the RVN), and sorties (to 418,206, almost double the 1963 figure), the initiative was slipping away. More and more, the U.S.-supported RVN armed forces, instead of taking offensive action, reverted merely to reacting to Viet Cong attacks. That fact is borne out by MACV weekly reports on "significant operations" that averaged about two or three a week. Significantly, less than half of these operations fall in the category of combined operations supported by airmobile elements. Detailed statistical data on airmobile operations were found to be practically nonexistent. Over-all, 803 preplanned operations plus 1,600 quick-reaction operations involving airmobile elements were
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undertaken in the last half of 1963 and the first six months of 1964. On a weekly basis, this averages out to about 15 preplanned and 30 quick-reaction operations per week. Obviously, most of them were not significant.
As the size and frequency of Viet Cong attacks increased during 1964, the RVN Army became increasingly dependent on tactical air and helicopter support for mobility, firepower, and logistical support. The Commanding General MACV stated that without U.S. Army and Air Force air support, the RVN Army's position would have become untenable. U.S. support, he judged, required an increase in the effectiveness of both fighter planes and armed helicopters, under the existing rules of engagement.
As in 1962 and 1963, the helicopter with its agility and capability of operating in marginal weather proved to be complementary to the fighter. The armed helicopter also proved effective in its primary role, escorting and protecting transports. Usually the armed helicopters succeeded in fixing the Viet Cong in position until the fighters arrived with their heavier ordnance. Suppressive fires took the form of aerial fire against enemy ground troops. The fires were delivered in response to observed enemy ground fire or when targets were identified by RVN Army commanders on the scene.
Armed helicopters did not exclusively support airlanding operations. In a typical airlanded assault, RVN and U.S. fixed wing aircraft delivered a heavy preparatory strike, then armed helicopters followed with suppressive fire to neutralize enemy positions that might have escaped the first strike. Suppressive fire continued until the airlanding was completed and the transports had left. On occasion, the armed helicopters remained to
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help the landed forces.
The ratio of armed helicopters to transports varied according to area and anticipated resistance. In the I Corps zone in the north, the ratio was generally one escort to five transports; in the II and IV Corps zones it increased to one to three; in the most active III Corps zone the ratio was one to two.
Night operations came into their own in 1964. An important reason for this was the increase in Viet Cong nighttime actions. The first U.S. experiment in night operations took place in October of 1963 when 80 RVN Army men were landed under cover of darkness. In this instance, the lead helicopter guided the formation to the landing zone by using its lights. The following aircraft then did the same. In June 1964, in another try, 70 Vietnamese were landed just after dark without landing lights. For lack of communications, all but the first ship had difficulty locating the landing zone. It proved necessary to use flares to illuminate the area. In subsequent operations flares were used quite generally. But flares had a way of interfering with the operations because they tended to blind pilots, give away the landing zone, and reveal the aircraft. To overcome these problems, studies were undertaken that considered, among other things, instrument training and navigational aids for helicopter pilots (only 5 percent of the pilots had such training), and pathfinders. Training was impractical, pathfinders would have compromised surprise. At the close of 1964, no solution had been found. Success in night operations may be described as modest.
In 1965, the trends of 1964 continued, requiring an even greater U.S.
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effort to stabilize the situation. Airmobile operations, more than before, were needed to restore the status quo, rescue trapped RVN forces, and break up recognized or anticipated Viet Cong concentrations. VC tactics and weapons are now much improved and more sophisticated than they ever were before. Examples are their primitive, but effective, acoustical burrows, spiking of potential landing zone sites, and concentration of antiaircraft weapons. Not only do the Viet Cong "show little fear" of the armed UH-1B, they have developed a new tactic of concealing and camouflaging their weapons, holding their fire during the reconnaissance flights and prelanding air strikes the better to fight off the transports on arrival. Consequently it appears that the armed escorts would require heavier ordnance to destroy the Viet Cong in prepared positions or at least deter their assault from positions too well concealed for detection.
In looking back at three and a half years of U.S. Army supported airmobile operations in Vietnam, one may conclude that such operations in the environment of Vietnam have been a qualified success. Limiting factors, however, are the terrain, weather, and special conditions under which this U.S. commitment prevails.
Foremost among special limiting conditions is the fact that U.S. forces operate in an advisory and supporting role where persuasion replaces control. The political-strategic escalation of the conflict, on the other hand, has tended to increase U.S. influence, if only because without it, the downfall of the RVN would only be a matter of time.
However, airmobile operations, it appears, were more successful
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during 1962 and 1963. Once the enemy learned to adjust to this challenge to his objectives, and then countered with improved tactics and techniques (was well as increased numbers of men and weapons), the initial RVN-U.S. advantage decreased. History teaches us that every new weapon or tactic eventually meets its equal. Since airmobile operations, as applied and practiced in Vietnam, depend on the functioning of combined operations—ground and air—a judgment on the ultimate validity of airmobile operations would be premature. It is suggested, however, that the present urgent challenge can be met successfully only if all elements of combined operations can be brought to bear on the enemy not only in concerted and co-ordinated fashion, but with near equal effectiveness of the parts. Meantime, airmobile operations appear to be one of the decisive factors that are preventing a Communist takeover in the RVN, and therefore contribute a vital weapon in the application of U.S. policy, strategy, and tactics.
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As of the end of 1964, information compiled from MACV monthly Command Evaluation Reports indicated that the frequency of airmobile operations, of all categories, had increased to an average of about 60 per week, throughout Vietnam. This was reflected further by statistics on Army Aviation operations, which showed a total of 427,120 sorties flown in CY 64, an average of 8,213 per week. Of these, 333,397 were combat support missions (weekly average: 6,411) which carried a total of 576,682 passengers, most of whom were troops, for an average weekly lift of 11,090 personnel. The number of rotary wing aircraft hit by hostile fire was 740, of which 69 were shot down, or lost to hostile fire. This demonstrated an average loss of all types of Army Aviation craft to less than 5 per month, and reflected that only 1 sortie in each 426 flown was hit by hostile fire. The cumulative total of Army craft shot down or lost from hostile fire, from 1 January 1962 through 31 December 1964, was 126, all types, which represented a negligible percentage rate in comparison to total sorties flown. The largest single airmobile lift in 1964 had been the movement of a 1300-man force of Vietnamese Marines, in a preplanned operation involving more than 40 USA helicopters in addition to other transport aircraft.
In early 1965, both the weekly averages of Army aircraft sorties flown and the frequency and intensity of airmobile operations commenced to increase sharply. The airlift capability was increased by the
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introduction of four more Airmobile (Light Helicopter) Companies into Vietnam. With the commencement of major Viet Cong offensives in April 1965, larger ARVN reaction force lifts were employed in several significant battles. The effectiveness of their employment was countered to a large extent, however, but the Viet Cong innovation of defensive ambush tactics against potential landing zones in the battle areas.
The Viet Cong, while attacking their objective with a substantial portion of their forces, marshalled sufficient forces to ambush the several most likely landing zones within a probable reinforcement radius, thus anticipating the arrival of large heliborne ARVN reaction forces. This tactic was a refinement and further development of that first used at Ap Bac; now made possible by the employment of larger Viet Cong forces of up to and exceeding reinforced regimental size.
This tactic proved costly to the ARVN multi-battalion-size reaction forces at the battle of Binh Gia (December 1964) and more recently at Song Be, Ba Gia, and Dong Koai. In spite of heavily increased tactical air prelanding strike sorties and armed helicopter suppression, the ARVN forces incurred heavy casualties in the landing zone areas. The primary problems in each of these battles were: better camouflage by the Viet Cong; larger ambush forces-in-waiting; inadequate initial intelligence of the size of the VC forces engaged in the action or their dispositions; and lack of adequate advance reconnaissance of the probably landing sites, further confounded by the Viet Cong use of camouflage and withholding of fire until the landing tough-down.
The airlanded introduction of four ARVN battalions, totaling over
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2000 men, utilizing the assets of six helicopter companies, in the reaction effort at the battle of Dong Xoai (12 June 1965) represents one of the largest airmobile reaction operations to date.
Current reports in mid-1965 show that the frequency of airmobile operations throughout RVN has risen to approximately 120 per week. As of the end of June, total sorties for the first half of 1965 flown by Army aircraft were 291,581, at a weekly average of 13,254 sorties, of which 263,814 (weekly average: 11,992) were combat support sorties, which carried 252,691 passengers (weekly average: 19,966). This represents nearly a doubling of the comparable average figures for 1964. The number of U.S. Army aircraft in Vietnam by 31 May 1965 had increased to 608, all types, of which over two-thirds were rotary-wing. Of the 291,581 sorties from 1 January to 19 June 1965, only 709 craft were hit by hostile fire, an average of 1 hit out of 411 sorties. Thus the hit and loss rate from enemy fire has increased only slightly in spite of a doubling of utilization.
At the writing of this report, the Viet Cong spring offensive is still under way. A primary objective of that effort appears to be the cutting of all major routes of communications from south to north—roads and railroads—in RVN, at which the Viet Cong have attained already a marked degree of success. With the resultant reduction of unimpeded ground-road movement capability, the ability of the US/ARVN forces to move and supply by air assumes an urgently increasing importance and necessity. Thus, actions are now under way to increase materially, the airmobile capability and Army Aviation aircraft assets
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in Vietnam by the programmed introduction of additional airmobile helicopter and support units within the near future. The concept and feasibility of airmobile operations and the flexible utility of aircraft assets have been firmly accepted and established at all echelons of decision.
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