After Action Reports 24

A. General: The 25th Infantry Division participated in the conclusion of Phase II and in the initiation of Phase III of Operation Toan Thang. The Division's efforts were keyed to finding, fighting and destroying the enemy in his base areas in order to preempt his efforts for a new offensive. Indications were that the enemy was still attempting to launch a follow-up to the “3rd Offensive.” The prevailing dry season enabled the Division to exert its full armor, mechanized and heliborne mobility in search of the enemy.

As the reporting period began, the level of enemy activity varied from light to moderate. The last week of February, however, saw the highest level of enemy activity since the third offensive in August and September of 1968. It became clear that the earlier lull had been used by the enemy to prepare for the general offensive of the Winter-Spring campaign.

The 1st Brigade operation with three maneuver battalions (4th Battalion, 9th Infantry: 3rd Battalion, 22nd Infantry; and 4th Battalion, 23rd Infantry, (Mechanized) during most of the month of February. On 28 February, the 2nd Battalion, 27th Infantry, was placed under the operational control of the 1st Brigade, as intelligence reports indicated TAY NINH CITY as a probably target for the Winter-Spring offensive.. These units, working in conjunction with the South Vietnamese airborne battalions (1st/ 2nd/ 3rd/ 5th/ 6th/ 7th/ 8th/ 9th at various times, and the 1st and 3rd South Vietnamese Marine Battalions) conducted offensive operations to preempt enemy initiatives against TAY NINH CITY. Later, during March, the 2nd Battalion, 27th Infantry was returned to the 2nd Brigade because the majority of contacts were being made in this area. Throughout the period, Troop C, 3rd Squadron, 17th Air Cavalry, flew in support of the 1st Brigade.

Until the departure of the 2nd Battalion, 27th Infantry, the 2nd Brigade was comprised of five Maneuver Battalions. These were the 2nd Battalion, 14th Infantry; 2nd Battalion 34th Armor (-); 2nd Battalion, 12th Infantry; 1st Battalion 5th Infantry (Mechanized); and the 2nd Battalion, 27th Infantry. During March, the Brigade regained the 2nd Battalion, 27th Infantry and gained the 1st Battalion, 505th Airborne Infantry, which was to continue operations in the SUGARMILL (XT4406) area, begun by the 1st Air Cavalry Division. The Brigade oriented its operations along the BA THU-DUC LAP (XT5505) - MY HANH (XT6302) and BINH THUY (XS6297) infiltration corridors, and the PHU HOA DONG corridor along the Saigon River. Numerous other operations were conducted in the HOBO WOODS (XT6232), BOI LOI (XT4637), FILHOL (XT6720) CITADEL (XT5325), TRANG BANG (XT4919) and TRUNG LAP (XT5923) areas. The Brigade continued daily convoy security missions between CU CHI Base Camp and DUC HOA along Highways 8A and TL10, between HOC MON and TRANG BANG on Highway 1, and portions of Highways 6A, 7A and TL15. In addition, the Brigade was responsible for the defense of the PHUY CUONG / BA BEP Bridges, and daily designated an infantry battalion as a Division Ready Reaction Force. A number of combined operations were conducted with the 1st Vietnamese Marines and the 4th Battalion, 7th Regiment, 5th ARVN Division along the Saigon River and in the FILHOL plantation area.

The 3rd Brigade operated in the northeastern portion of the Division's TAOR with two maneuver battalions, the 1st Battalion, 27th Infantry and the 2nd Battalion, 22nd Infantry (Mechanized). The Brigade conducted extensive sweep operations in the BEN CUI (xt4645) and MICHELIN (XT5553) rubber plantations and conducted a large relocation of the inhabitants from the MICHELIN to TRI TAM District. The Brigade's efforts were directed towards Military Pacification by the destruction of enemy forces in a priority established through coordination with the chiefs of KHI EN HANH and TRI TAM Districts. The Brigade also conducted operations in the BOI LOI Woods (XT4637) and TRAPEZOID (XT5742) areas.

Activity during the month of February developed slowly. Soldiers from Troop C, 3rd Squadron, 4th Cavalry, engaged the enemy in a skirmish north of GO DAU HA (XT388312) on 1 February, killing five enemy and capturing six small arms. The following day, 2 February, they returned to this area and reestablished contact about noon. Troop B engaged an estimated enemy company entrenched in bunkers. Coordinated artillery and air strikes were placed upon the position, and Troop B was reinforced by Tr9oops A and C, and by elements of the 1st Vietnamese Marines. This action resulted in 30 enemy killed and 16 wounded.

Later that week (8 February) fighting was centered near the Division Headquarters at CU CHI. Companies A and B, 2nd Battalion, 14th Infantry, were conducting a series of combat assaults along the northern edge of the FILHOL rubber plantation (XT632236). On their third landing, they received small arms and automatic weapons fire. This engagement lasted three hours. Sweeps through the enemy position disclosed 12 enemy dead. At this same time, Companies A and B of the 1st Battalion 5th Infantry (Mechanized) engaged an enemy force just to the east (XT624220) and killed 25 North Vietnamese (p4) regulars. The following day, elements of the 2nd Brigade attempted to reestablish contact in this area, instead, they located a sizable cache of arms, ammunition and explosives.

From this point on, the Division intensified its surveillance and search of the TAOR. With last year's “TET” offensive in mind, and in heed of the intelligence predictions for another major offensive, all efforts were bent toward gaining early contact with the enemy and the denial of his ammunition and food supplies.

On 16 February, contact was made just south of the HOBO WOODS with an estimated enemy company. Company A, 1st Battalion, 5th Infantry (Mechanized), made initial contact. Reinforced by Company A, 2nd Battalion, 14th Infantry, their combined fire power resulted in 33 enemy dead. The discovery of caches increased rapidly. 1st Brigade elements discovered two underground warehouse bunkers, eleven kilometers northeast of TAY NINH (XT370556), on 18 February, containing 1700 rounds of mortar, recoilless rifle and RPG ammunition. A combined strike by Air Force jets and Cobra Gunships of the 17th Air Cavalry destroyed 2110 tons of rice, five tons of millet and two and one half tons of salt in an area northwest of TAY NINH (WT966568). Results were confirmed by a ground assessment by the 3rd Battalion, 22nd Infantry.

In the 3rd Brigade area, 28 enemy were killed on 21 February. A listening post from Company B, 2nd Battalion, 22nd Infantry (Mechanized), detected movement near their night laager several kilometers west of DAU TIENG (XT448452) The Battalion initiated the action with organic weapons and supporting artillery, and the engagement lasted for two and one; half hours. Documents captured identified the enemy as the 5th Battalion, 95C Vietnamese Regiment. These contacts signaled the beginning of the Winter / Spring offensive.

On 23 February, the enemy launched the first wave of the anticipated offensive. The 2nd Brigade had a Patrol Base named “DIAMOND I” three kilometers from the Cambodian border (XT337187), manned by the 2nd Battalion, 27th Infantry. After a ten minute barrage of mortar and automatic weapons fire, the enemy mounted a massive assault from the west and the south. In spite of all available fires directed against the attackers, the enemy penetrated the protective wire and occupied three defensive bunkers on the southwest side of the perimeter. Direct fire from artillery within the perimeter halted and repelled the enemy penetration. At 0530 hours, a sweep of the battle area disclosed 11 enemy dead.

Meanwhile, DAU TIENG Base Camp (XT4947)), received a similar attack by a reinforced sapper battalion preceded by a mortar and rocket attack. A squad sized enemy force penetrated the eastern side of the perimeter, made their way into the aircraft revetments and planted satchel charges, damaging two aircraft (OV-10) and one helicopter (LOH). A penetration of the southern sector was contained by an interior reaction force. This attack cost the enemy 73 dead and 14 captured, along with the loss of 33 weapons and 205 satchel charges. (p5)

While both DAU TIENG and Patrol Base DIAMOND I were under attack, a third enemy attack developed at Fire Support Base MAHONE II (XT521419), located in the TRAPEZOID area several kilometers south of DAU TIENG. The fire support base received a heavy volume of small arms, automatic weapons, RPG and mortar fire. Tear Gas was also used against one portion of the perimeter in an apparent attempt to mask a penetration. This attempt failed in the face of the coordinated defensive fires. The enemy was forced into a complete withdrawal to the northeast through the MICHELIN Rubber Plantation. The enemy left 38 dead behind.

On the afternoon of 24 February, interrogation of an enemy prisoner revealed plans for a second attack on Patrol Base DIAMOND. Radar and visual reconnaissance of movement around the base confirmed this. Interdictory fire and air strikes were initiated immediately. At 0100 hours, the base again came under attack. The base responded with organic weapons, artillery fires from three batteries, helicopter gunships, air strikes and artillery direct fire in a continuous coordinated volume of fire. US loses were one killed and three wounded. A sweep of the battle area at dawn disclosed 78 enemy dead. Early warning and a heavy concentration of coordinated firepower produced his victory.

The Division Base Camp at CU CHI (XT6315) came under attack at 0400 hours on 26 February. Fighting began along the northwestern portion of the perimeter. At 0430 hours, the camp began receiving fire from 122 mm and 107mm rockets and 75mm recoilless rifles, coordinated with a probe on the western sector and a subsequent penetration of the southeastern sector, where a sapper team succeeded in destroying nine CH47 helicopters and damaging two other. The camp's interior defenses and air and artillery fires prevented any further exploitation. Thirty-one enemy were killed and eight captured during the fight. This attack on CU CHI concluded one of the most active weeks experienced during the quarter. One thousand and thirty-eight enemy were killed and four hundred and fifty-four weapons were captured.

Extensive riverine operations were conducted in the Division area during the month of February. On 8 February, the 3rd Brigade and the 28th River Assault Group began Operations HUCK FINN III along the upper Saigon River. The mission was to continue defoliation of the banks and to search areas not covered in Phase II. Large amounts of enemy supplies were uncovered in the densely vegetated tributaries, and by 15 February an additional 20 acres of shoreline were cleared.

On the western side of the Division TAOR, Operations KEEL HAUL I (8-11 February) and KEEL HAUL II (21-24 February) were conducted along the VAM CO DONG River. The Division provided ground reaction forces to exploit contacts made by naval patrol boats along the river. The success of these operations cannot be fully evaluated due to infrequent contact with the enemy. However, these operations did restrict enemy movement and use of base areas in this region. The concept of this combined operations will be further developed. (p6)

The month of March was characterized by continued heavy activity in all Brigade areas. The newly executed offensive had gained full momentum. The Division intensified its search for the enemy through extensive ground reconnaissance, air-mobile operations, and widespread aerial reconnaissance. This approach brought success, as elements of the Division began to hit the enemy in his staging areas.

Among the most successful operations during the month were in areas controlled by the 2nd Brigade deep within the CITADEL and BOI LOI WOODS. On March 4th, Company C, 2nd Battalion, 12th Infantry, performed a combat assault only eight miles northwest of CU CHI (XT547250) and encountered a heavy volume of fire from a well concealed and entrenched enemy battalion. The contact was reinforced by a task force of three rifle, one mechanized, and one tank company. Three thousand rounds of supporting artillery were fired. This engagement lasted until 1800 hours. An evening sweep of the area revealed 84 enemy dead. The combined forces established a night defensive position in the area. Early the next morning this position received a heavy attack by fire and a subsequent ground attack. Artillery, helicopters and fighters broke the assault, and caused the enemy to leave another 74 dead on the battlefield. U.S. casualties, by contrast, were light: 11 killed, 37 wounded.

The two day period, 17 to 19 March, produced several ill considered enemy attempts to defeat 2nd Brigade units. A night attack on Company A, 1st Battalion, 5th Infantry (Mechanized) resulted in 30 enemy dead on the 17th. Later that same day, Company C, 2nd Battalion, 27th Infantry, fought an engagement (XT565227) with an enemy force in an open area. Without reinforcement, through classic fire and maneuver, Company C killed 81 of the enemy, at a cost of one wounded U.S> soldier. This same enemy force attacked Company C two days later in a night defensive position in the same area. The cover of darkness did not improve their situation. They lost 33KIA again. The enemy became increasingly reckless as he attacked a night defensive position of Company A, 2nd Battalion, 12th Infantry. in the same area (XT-----) on 18 March The massed defensive fire around the position produced another 22 enemy dead. A similar night attack in the --------area (XT5------) on 19 March cost the enemy 26 killed when he fought Company C, ----Battalion, 5th Infantry (Mechanized). Numerous small encounters continued in this area during the next week. On 27 and 28 March, the Division made OPCON the 2lnd Battalion, 27th Infantry, and the 1st Battalion, ---th Infantry -------Air-borne to the 2nd Brigade in order to exploit the contact gained with the enemy in the area. During the month of March, the 2nd Brigade delivered a major defeat to the enemy units massed along the Saigon River infiltration corridor.

The 3rd Brigade oriented its operations toward making contact with the enemy in the MICHILIN and TRAPIZOID and around the TRANG Base camp. On the 6th of March, Company C, 2nd Battalion, 22nd Infantry (Mechanized) made contact with an enemy force entrenched in a bunker complex northwest of DAU TIENG (XT459503). Company C pinned the enemy to his positions with their machine guns, and directed artillery and air-strikes onto the bunkers. A search of the bunkers revealed 51 enemy killed. A second attack on Fire Support Base MAHONE II (XT521419) resulted in 21 enemy killed.

The month of March also produced several disastrous enemy ambush attempts against Divisional logistic convoys. The Division's convoy plans had been vastly improved during the past six month period. The very concept had been changed from merely defending the convoys to violent counter-attack of ambush forces. The convoys were reorganized into small, well dispersed, march units with more ground and airborne control elements. Only a small portion of the cargo vehicles could be caught in the normal 1500-1800 meter killing zone. Control elements could clear the zone rapidly and security elements could immediately establish a base of fire, while pre-positioned reaction forces quickly moved in to engage the enemy from different directions. Thus firmly fixed, the enemy would be destroyed in place by artillery and air strikes.

The first attempt came at 1205 hours, 11 March, against the DAU TIENG convoy near the BEN CUI Rubber Plantation. Companies A and C, 2nd Battalion, 22nd Infantry (Mechanized), blocked escape routes to the north and south, while Company B exerted direct pressure from the east. Combined with this maneuver, artillery and air strikes accounted for 77 enemy dead. Only three U.S> soldiers were wounded and the convoy arrived at DAU TIENG on schedule. The enemy tried again on 25 March along Highway 19 near the village of UIO CAO (XT4528). Quick reaction by Troop A, 3rd Squadron, 4th Cavalry, and combined fire support accounted for another 42 enemy dead.

The month closed with the same intense fighting. On 28 March, as the Division convoy moved toward TAY NINH along Highway 26, the enemy engaged the column with ineffective fire. The convoy quickly cleared the killing zone, and Troop A, 3rd Squadron, 4th Cavalry, again moved quickly to the contact area, and, supported by artillery, helicopter gun-ships and air strikes, routed the enemy force, killing a total of 82. On the following day Company A, 4th Battalion 23rd Infantry (Mechanized), while performing mounted reconnaissance ahead of a convoy, encountered a two-company force in the CAU KHOI Rubber (XT3649) at 1110 hours. Company C of the same unit reinforced the contact and with supporting fires they killed another 41 enemy.

April saw a general decrease in the larger enemy initiated contacts with the exception of the border area, where the enemy again made several unsuccessful attempts against 1st and 2nd Brigade patrol bases. Indications were that his plans were being modified. He would place increased emphasis on disruption of the pacification effort by attacks on GVN controlled hamlets, assassination and sabotage. U.S. Forces would be tied down by attacks by fire, attacks against supply routes, and by heavy ground attacks along the border, close to enemy sanctuaries. As the larger enemy concentrations became difficult to find, the Division spread its search wider, using smaller elements to cover more area. Mounted reconnaissance, platoon sized Eagle Flights, combat assaults, saturation patrolling, long range reconnaissance patrols, visual reconnaissance, and a variety of detection devices were employed. Increased emphasis was place on combined operations with Regional and Popular Forces, not only to improve their performance, but to cover more area. Greater emphasis was placed on night operations. These tactics produced results: The number of contacts was high, and the number of enemy killed and enemy weapons captured was the largest since May of 1968. (p8)

On the 2nd of April, Company D, 2nd Battalion, 12th Infantry, detected movement outside of its night defensive position near TRUNG LAP (XT556219). At 0045 hours, the Company engaged the enemy with organic weapons, artillery, and helicopter gun-ships,. The enemy returned fire with automatic weapons, RPGs and mortars, but inflicted no casualties. At first light, Company D counted 49 enemy bodies. On the following day, Company A, 4th Battalion, 23rd Infantry (Mechanized), in a combined operation with the 164th Regional Force Company north of the CAU KHOI Rubber Plantation (XT364494), engaged an enemy squad and killed six.

The 5th of April saw the beginning of another series of attacks on the 2nd Brigade's Patrol Base DIAMOND II, which was shifted along the border in the ANGEL'S WING sector (XT3322) as a lure for the enemy. Apparently the temptation was too great. At 0130 hours, 5 April, the base detected movement in the area and engaged it with artillery. The enemy responded with direct and indirect fire, followed by a ground assault. The defenders reacted with a carefully prepared fire plan. Organic weapons, artillery, light fire teams, aerial rocket artillery and air strikes broke the assault and made the enemy pay 20 to 1 for the attempt. Eighty-one enemy bodies were counted. U.S. losses were four killed and thirteen wounded. 27th Infantry, engaged an enemy company with artillery and helicopter gunships, killing another 16 of the enemy.

The enemy made another attempt against Patrol Base DIAMOND III early on the morning of 15 April (0315 hours). He had learned something from his previous defeats. This attack was launched from prepared fighting positions, was preceded and sustained by some 800 mortar and RPG rounds, and involved an estimated two enemy battalions. The defenders, however, were ready, since they had detected enemy movement by radar and listening posts, and initiated the contact with artillery. The Division supported DIAMOND III with the full arsenal at its disposal. The concentrated, continuous fire from automatic weapons, artillery, mortars, aerial delivered rockets and machine gun fire, and bomb sorties resulted in 198 enemy killed and eight captured. This success was achieved through the application of the fundamental principles of defense. The enemy was induced to fight at a place of our choice. This position had flat, well cleared fields of fire, protected fighting positions, and wire obstacles. All available supporting fires were pre-planned and well coordinated. The defenders were alert and had early warning of the enemy's approach. The same fundamentals would produce an even grater success later in the month at a place called FRONTIER CITY.

of TRANG BANG (XT575249). Reinforced by supporting fires, they killed 17 of the enemy. Two days later, in the same are (XT572244), elements of the 1st battalion, 5th Infantry (Mechanized) and the 2nd Battalion, 14th Infantry, under the operational control of the 2nd Battalion, 34th Armor, engaged an enemy force and killed 33.

On 11 April, Company B, 1st Battalion, 5th Infantry (Mechanized) was attacked in its night defensive position in the HOBO WOODS (XT560280) at 0320 hours. With the assistance of supporting fires, the company killed 33 enemy and incurred no casualties. The enemy returned two nights later to receive another beating. This time they lost another 24 killed. Apparently intent on revenge, the enemy hit Company B again on the 21st at 2145 hours (XT573262) and left another 21 dead outside the perimeter. Company B's losses for the three engagements were one man wounded an done armored personnel carrier destroyed.

The 3rd Squadron, 4th Cavalry, along with its Long Range Reconnaissance Patrol teams was active in and around the CITADEL throughout the month. They made numerous contacts and destroyed substantial amounts of enemy equipment. On 7 and 8 April, two patrols operating south of the BOI LOI (XT514347) detected small enemy units and engaged them, killing six. On the 9th of April, Troop B and one patrol located another group of enemy in this same area and killed 13 with organic weapons and helicopter gunships. The following day, a patrol detected an enemy platoon, again in the same area and killed 15 of them with artillery support.

Activity in the 3rd Brigade area consisted of sweeps through the MICHELIN (XT5554), BOI LOI WOODS and TRAPEZOID (XT5740). Numerous small contacts were made. The capture and destruction of enemy supplies and fortifications went on continuously. The base camp at DAU TIENG was harassed constantly by small arms and rocket attacks. On the 5th, 7th, 11th, 12th and 17th of April the camp was hit by rockets with total casualties of only four wounded and the loss of two trucks, one artillery piece and one building.

Extensive reconnaissance in the 1st Brigade area also proved successful. On 10 April, a helicopter from the 25th Aviation Battalion received ground fire over a wooded area near the border. Artillery and air strikes killed 63 enemy and destroyed a tunnel and bunker complex. Throughout the month in the TAY NINH area, the enemy provided a steady series of targets for air strikes by indiscriminately firing at the Division's aerial reconnaissance elements. (p10)

On the 16th of April, Company B, 4th Battalion, 23rd Infantry (Mechanized), while searching an area of previous air strikes (XT031794), discovered the bodies of 93 North Vietnamese soldiers. That same day Company A, 4th Battalion, 9th Infantry, engaged 12 enemy close to the border and killed 11 of them.

As the reporting period drew to a close, the Division reached a peak of success. Capitalizing on the enemy's desire for a moral victory, the Division again set the bait close to the border. Following a standard procedure, a well-entrenched company sized patrol base was established within two and one-half kilometers of the border (XT202242). Work on the base began on the morning of 24 April, and all defensive preparations were completed by darkness. Twenty-one sorties of CH-47 helicopters were used to bring in troops bulldozers, demolitions, fortification materials, crew served weapons and ammunition. The, following a synchronized plan, wire obstacles, claymore mines, fighting bunkers, covered sleeping positions, mortar and howitzer pits, ammunition bunkers and an observation tower were all completed in one day. In addition, fields of fire were cleared all around the position.

This patrol base was named FRONTIER CITY and was manned by elements of the 4th Battalion, 9th Infantry. At 2200 hours, 25 Apr, radar in the observation tower began to detect movement southwest of the base. As the movement increased, the defenders placed artillery fire on the wooded area southwest of the base, and called for assistance of flare ships, helicopter gunships, and tactical fighters to engage all of the suspected enemy locations.

The enemy responded with a barrage of 107mm rockets, 82mm mortars, RPG's and anti-aircraft machine gun fire. At the height of the fire fight, three batteries of artillery and an AC-47 gunship attacked along the southeast and northwest sides of the base. All fires were coordinated from the base observation tower, and the 81mm mortars in the base marked targets with WP rounds.

At 0035 hours, 26 April, the enemy launched a battalion sized ground attack from the southwest. In the face of the direct fire from the infantrymen in the base and all supporting fires, only 11 of the enemy reached the wire and none made it beyond. At this point, the enemy began to withdraw, but the air and artillery fire continued to pound him. A police of the battle area on 26 April revealed 214 enemy dead. Friendly casualties amounted to one man evacuated for shrapnel wounds. Interrogation of the six enemy prisoners taken revealed that the 271st North Vietnamese Army Regiment was the attacking force.

The accelerated pacification campaign, “Colors Up,” was completed on 17 February 1969. This program, which had commenced on 1 November 1968, was designed to raise the MACV Hamlet evaluation system (HES) ratings of specific hamlets within South Vietnam. Upon completion of this program, 57 hamlets were up-graded from ratings of D (contested) and E (VC controlled), to those controlled by the Government of Vietnam. The overall pacification effort was not seriously affected by the enemy attacks during February. There are indications that the disruption of this effort will be the primary enemy objective during the spring and summer.

Several new innovations were developed during this period to deny the enemy the use of sanctuaries. The first of these, “THUNDERBOLT” involves dropping cluster bomb units (CBU) into selected areas to channel the enemy into target areas which are then saturated with multiple B-52 strikes within a 24 hours period. Choice areas are then selected for ground exploitation. Afterwards, both artillery and radar guided air strikes are directed into the area at night to further disrupt any enemy attempt to regroup.

A similar technique named `RED LIGHTNING”, involves first saturating the area with CS (riot control agent) munitions. This is followed by B-52 air strikes. Again, selected areas are exploited by ground troops and after their extraction; a follow up of artillery and air strikes is made at night. These techniques have seriously deteriorated the enemy's combat effectiveness by forcing him to move constantly.

NIGHT HAWK is a somewhat different technique. Artillery flares illuminate the periphery of selected areas. Within these areas, UH-1 helicopters scan the area with night observation devices (ambient light), which intensify the light provided by the distant flares. When targets are observed, they are

Engineer activity during this period, in addition to their many daily functions, was oriented toward the CITADEL. They were to enter this traditional enemy stronghold, and deny him the use of the area by destroying tunnel complexes, trench line, fighting positions, pun ji pits, bunkers, and food and weapons caches.

The following section is a detailed daily account of significant combat actions as they occurred in the Divisional TAOR during the reporting period. Enclosure 1, Tab A, contains the organizational structure of the Division. Enclosure 2, Tab B, contains the Division Commander's evaluation of the use of CS gas during combat operations. Enclosure 3, Tab C, concerns a new device to detect trip wires and detonate booby traps. Enclosure 4, Tab D, is the detailed Combat After Action Report on the Defense of Patrol Base FRONTIER CITY.

The USAF TACP assigned to support the Division was responsible for controlling tactical air strikes, visual reconnaissance, assisting in the development of B-52 targets and B-52 target bomb damage assessment. There were 2582 tactical air sorties flown in support of the Division. The air strikes were in support of troops in contact, landing zone prep-operations, pre-strikes and harassing and interdictory strikes. Bomb damage assessment was:

(3) (C ) During this period there were 81 B-52 strikes consisting of six sorties each flown in support of the Division operations. Most of the targets were located in War Zone C, the Crescent, the Trapezoid, and the Boi Loi Woods. Over 12,000 tons were dropped on troop concentrations, base camp storage areas, communications centers, and infiltration routes. A bomb damage assessment was made on each target. Reports from agents, ralliers and prisoners-of-war indicated that the B-52 strikes have contributed greatly to the combat power of the Division and are in large part responsible for the enemy being defeated in each move he made. These same reports estimate the number of enemy dead and wounded by the strikes well into the thousands, and uncountable quantities of supplies and equipment lost.

(4) (C ) The Division Chemical Section, and the 9th Chemical Detachment continued to support division operations by employment of tactical and bulk CS, personnel detection, and defoliation missions. During the reporting period a total of 188 EI58 CS canisters and 1216 M7A3 CS grenades were helicopter-dropped in support of troops in contact. A total of 175,840 lbs of micro-pulverized CS powder was dropped by CH-47 to restrict known or suspected enemy infiltration routes, base camps and rocket and mortar sites. Additionally, 24,700 lbs of CS powder were employed utilizing the BLU-52 system. Two hundred and forty lbs of CS powder were employed in bunkers and tunnels. A total of 14,000 gallons of defoliant were used around base camps and along the Saigon and Oriental Rivers. Assistance was also provided to the 25th ARVN Division. A total of 280 hours of flying was devoted to chemical personnel detection missions using the airborne personnel detector. During the reporting period an AGAVENCO Sprayer and three new airborne personnel detectors were received in the Division.

(5) (C ) During the reporting period, Army combat aviation support was provided to the 25th Inf. Div. By organic and non-organic aviation units. Organic aviation units providing support included the Division Artillery Aviation Section, the 25th Avn Bn, D Troop, 3rd Sqdn, 4th Cav; 1st, 2nd and 3rd Bde Aviation Sections, and E Co, 725th Maint. Bn. Non-organic air support was furnished to the Division by units of the 12th Combat Aviation Group. Primary assault helicopter companies and CH-47 aircraft were provided primarily by the 269th Combat Aviation Battalion whose units include the 116th Assault Helicopter Company, 187th Helicopter Company, and 242nd Assault Support Helicopter Company. During the period, the 269th flew the following in support; of the 25th Infantry division: sorties flown - 45,972; passengers transported 57,444.

(6) (C ) Aerial surveillance and reconnaissance missions were flown in the TAOI by organic aviation units consisting of Troop C, 3rd Squdn, 17th Cavalry, of the 12th Combat Aviation Group; the 73rd Surveillance Company (Mohawk), and the 4th Reconnaissance Airplane Company (Birdog). Primary aero-medical evacuation of wounded was provided the Division by the 159th Medical Company.

(a) The 588th Engineer Battalion (Combat) with the 362nd Engineer Company (Light Equipment) and the 544th Engineer Company (Construction Support) attached, operated from Tay Ninh and Dau Tieng and provided engineer support in the northern portion of the Division TAOI. Significant operations included repair of the MSR's, resurfacing of Thien Ngon Airfield, construction of aircraft parking facilities at Tay Ninh and Dau Tieng, operations of the quarry at Nui Ba Den, and various MCA projects.

(b) The 544th Engineer Battalion (Construction) with the 104th Dump Truck Company and the 515th Asphalt Platoon attached, operated from Cu Chi and provided support in the southern portion of the Division TAOI. Significant operations included repair of MSR, paving of the MSR from CP17 to Go Dau Ha, construction of aircraft parking facilities at Cu Chi airfield starting on 14 April 69, operation of an asphalt plant at Cu Chi land various MCA projects.

The 3rd Battalion (155mm/8”), 13th Artillery provided general support for the division. However, due to a lack of artillery to adequately cover positions in the 2nd Brigade TAOI, 155mm batteries were occasionally assigned a DS mission. A 155mm battery was also assigned a DS mission to support the 3rd Squadron, 4th Cavalry, operating under division control, until this DS mission was given to the nearest DS battalion.

(b) The significant increase in the Duffel-bag program during this period required the establishment of new procedures for artillery exploitation of the Air Force DART system to monitor the devices, as well as the establishment of a ground monitoring station on Nui Ba Den. A significant amount of coordination was required to get the increased Duffel-bag Program operating efficiently. New lines of communication were established to permit rapid exploitation of targets obtained by activation of the anti-intrusion devices.

(c ) Ammunition expenditures for the period were reduced due to a reduction of the ASR. In order to operate under the reduction, ammunition expenditures on targets developed by sensor devices, SLAR, Red Haze, visual and photo reconnaissance were significantly reduced. The expenditure reduction occurred at a time when results from all intelligence gathering devices were being coordinated under the Target Information Center to produce a significant increase in reliable intelligence targets. A request to higher headquarters for additional ammunition to exploit the intelligence targets was initiated. Expenditures of artillery ammunition by the Division Artillery were:

(a) In the area of FM radio communications, one of the most significant activities was the development and implementation of a frequency management plan for Nui Ba Den mountain. This mountain with almost 1000 meters elevation makes an ideal retransmission site in the otherwise flat terrain of the III Corps area. Thus, almost 60 retransmission nets from 5 US and 2 ARVN major commands had migrated there, and because of virtually autonomous operations, severe interference problems were developing. With the cooperation of the Ii Field Force, Viet Nam, Signal Officer and the Signal Officers of the major commands concerned, retransmission stations which could operate feasibly elsewhere were relocated, coordinated frequency management began, and more effective communications have been provided all concerned. Through the Signal Officer, Nui Ba Den Provisional Company, the Division Signal Officer has continued to exercise technical control of the retransmission facility which is now operating 46 nets for 6 US and 2 ARVN major commands. In addition, the coordination and management has allowed additional nets to be operated when the tactical situation required without any problems.

Other problems of the Division Signal Office have been in the area of secure page copy tele-communications capability from the division through the brigade to battalion forward operating locations. In addition to providing the usual communications support to the division, the 125th Signal Battalion further expanded its multi-channel radio relay support of the forward operating locations. During the month of April, the highest level of commitment was achieved with radio relay systems operating between 19 forward locations and the three principal base camps. All battalion forward CP's as well as several infantry company and artillery battery fire support bases were supported.

(b) The 86th Signal Battalion, 1st Signal Brigade continued to provide Corps Area Communications Systems support for the division, including operation of administrative telephone systems on the three major base camps, base camp cable plants, and inter-base camp multi-channel radio systems, which by providing circuits for divisional use made possible the forward commitment of the divisional radio relay systems.

(1) (U) The Doctrine, Organization and Training (DOT) section of G-3 expanded its area of interest and responsibility in R&D items and ran the Lightning Reinforcement Training School, the Lightning Leaders Course, and the Lightning Mines, Booby Traps, and Tunnel Course. The Reinforcement Training School, a five day orientation on Vietnam, was completed by 5168 personnel between 1 February and 30 April. The Mines, Booby Traps, and Tunnel Course, a one day course of instruction on enemy mines, booby traps and tunnels, was completed by 5340 personnel. The ten day field leadership exercise for fire team and squad leaders, conducted by the Lightning Combat Leaders Course (LCLC) was attended by 573 students. Other divisional courses of instruction, the instructing unit and the number of trainees for the period of this report are as follows:

(3) (U) During the reporting period the Lightning Reinforcement Mobile Training Team (MIT) conducted 106mm Recoilless Rifle Training for the 25th ARVN Infantry Division. A Mobile Training Team from the Lightning Mines, Booby Traps and tunnels School conducted mines and booby trap training for the 5th ARVN Infantry Division.

(1) (C) Enemy activity during the month of February consisted of: 1. The completion of reconnaissance training and resupply; 2. An early celebration of Tet, and 3. Disposition of some forces toward final staging areas and initiation of the general offensive phase of the Winter-Spring Campaign. Enemy activity dropped to a low level during the Tet Holiday period, lower than it had been for the four previous months. The rate of activity, however, picked up again during the last week and a half of the month to a level equal to that of the 3rd Offensive in August-September 1968.

The COSVN Main Force units were involved in scattered major actions, but did not engage in sustained offensive activity as expected. Preemptive actions by the 25th Infantry Division along the lines of communication into Saigon had, earlier in the year, disrupted the enemy time schedule and objectives for the Winter-Spring Campaign. This same pressure continued to be applied throughout February and consequently resulted in alternate targets being selected by the enemy.

The 9th VC/NVA Division was deployed along the Cambodian border for the entire month continuing its reconnaissance in areas west of Saigon. The 7th NVA Division was positioned in the Fishhook area during most of February, but deployed one of its regiments, the 141st, to the south for action in the Michelin Plantation and the Trapezoid area during the last week of the month.

The 1st NVA Division continued to operate from base camp areas in the Crescent while conducting reconnaissance in the Trang Bang - Go Dau Ha areas. In SR-1, the 88th Regiment was the only unit which engaged in major contact. The SR-1 forces operated in support of COSVN sapper elements which conducted attacks on Dau Tieng and Cu Chi Base Camps on the 23rd and 26th of February. In SR-2, enemy forces avoided contact and continued efforts to enhance their infrastructure and logistical base. Evidence indicated that the enemy intended to increase PSYWAR activities against allied troops

final phase of the Winter-Spring Campaign. An overall high rate of activity was sustained similar to the latter part of February. Reports were received indicating the last big push of the offensive was to take place during 21-25 March. However, this failed to occur. COSVN Main Force units were active throughout the month. The 9th Division operated out of base camp areas along the Cambodian border, and all three regiments of the division were identified in major contacts SW of Tay Ninh City and east of the Angel's Wing. The division attempted to attack Tay Ninh City from the southwest on three occasions, but was intercepted and defeated each time by the ARVN Airborne. The 25th Division provided artillery and air support to these actions. The 18B, 95C and 101D Regiments were all identified as being the maneuver elements of the 1st NVA Division. All three of these regiments were identified in major contacts.

At the beginning of the month, elements of the 7th NVA Division Headquarters and the 209th Regiment deployed southward leaving the 165th Regiment to guard supply lines along the Saigon River. The 7th Division intended to cause heavy losses on allied forces, protect supply lines into the Saigon River Corridor and disrupt the GVN Pacification Program in the Michelin Plantation area. Allied Forces, including elements of the 3rd Brigade, 25th Infantry Division, countered the enemy action in “Operation Atlas Wedge” during the latter half of the month, inflicting heavy casualties on enemy forces and completely denying him the fulfillment of his objectives.

The results of the Winter - Spring Campaign were discussed and plans were made for a Summer Campaign. The COSVN Main Force divisions withdrew to rear base areas in Cambodia and War Zone C, and conducted training and received replacements. However, each of the divisions maintained one regiment in an offensive posture during the month and were engaged in heavy contact. Enemy action, in each major contact, was anticipated before the engagement was initiated and allowed 25th Infantry Division forces to achieve maximum use of available firepower and support during the peak of battle.

In SR-1, activity was heavy in the Citadel and lower Boi Loi Woods, while SR-2 was relatively inactive and continued to rebuild its infrastructure. The Tay Ninh provincial battalions avoided significant contact during the month. During April a total of 2058 VC/NVA were KIA (BC). The most notable engagements were:

and disseminated information gained from visual reconnaissance and interpretation of panchromatic camouflage detection, infra-red and SLAR imagery. Daylight, direct support Mohawk aircraft flew 66 visual reconnaissance and 49 photo missions in February, 66 visual and 36 photo missions in March, and 41 visual and 68 photo missions in April. Phase III, Direct Support of the OV-1 Mohawk Evaluation test was extended 30 days and ended on 18 March. Due to the excellent results this Division experienced during the direct support phase, it was gratifying to learn that direct support was extended until conclusions and recommendations are made from the test date.

b. Ten sensor devices at FSB Mahone II (XT62--) provided early warning of an NVA/VC attack 15 March 1969. The results of the attack were 21 VC/NVA KBA (BC) w/boosters, 4 RPG-2 launchers, 1 RPG-7 launcher, one 60mm mortar tube w/base-plate, 22 60mm rds, 35 Chicom HG's, 8 AK-47's, one flame-thrower, and three pounds of documents captured.

correlate information from sensors, aerial photography, visual sightings and all other intelligence sources to develop and confirm exploitable targets. Developed targets are disseminated to operational elements. When more data is needed to confirm or pinpoint a suspected target, further intelligence gathering efforts are recommended. The 45 targets developed and exploited during the month of April yielded 91 KIA/KBA (BC), 108 bunkers destroyed, 34 bunkers damaged, 2 structures destroyed, 6 secondary explosions, 2 secondary fires, 6 crew served weapons (.51 cal MG's destroyed, and 1 weapons cache discovered.

(7) (C) During the period 1 February to 30 April 1969, members of the Counter-intelligence Section were continuously involved in the production of timely and readily exploitable tactical intelligence in support of the units of the 25th Infantry Division. Through aggressive utilization of source nets, and the actual participation by CI case officers and sources with tactical units of the Division in the exploitation of developed targets, the CI Section continued to provide meaningful intelligence support essential to operations in this area.

(a) In addition to tactical intelligence support the CI Section provided a wide range of counter-intelligence services to the Division. The administration of the Volunteer Informant Program (VIP) has shown steady increase in FY69 with an anticipated third quarter monthly average of over 22 informants. This represents a major step from the 1st quarter of 6 informants, and a significant improvement on the 2nd quarter monthly average of 14 informants.

(b) At the direction of the Chief of Staff, the Counter-intelligence Section conducted a major investigative survey of the sapper attack on Cu Chi Base Camp of 26 February 1969. Over a three day period, twelve special agents from the CI Section interviewed over 150 persons concerning the events of the night of 25 - 26 February. In excess of 200 man hours were expended in the interviews, analysis, and compilation of information, and in the preparation of exhibits. This in depth investigation made possible the preparation of an accurate and detailed report of the infiltration of the base camp which was submitted by HQ's, 25th Infantry Division to HQ's USARV. The study provided significant recommendations based on the findings for improvements to base camp security.

(c) During March 1969, a total of seven VC working on Cu Chi Base Camp were apprehended through the joint efforts of the Vietnamese MSS, National Police, and the CI Section, 25th MID. Subsequent interrogation revealed the identities of eight former employees of the base suspected of being VC. In an attempt to tighten controls on the hiring of indigenous employees, a Civilian Personnel Office (CPO) has been established to centralize and standardize the processing of new permanent employees to include requests for MSS clearances. New procedures have been instituted at the Main Gate for searching indigenous employees for explosives and other unauthorized items, and for checking for bogus or erroneous identification.

(8) (C) During February, the VCI Exploitation Team employed Kit Carson Scouts and 3 sources in operations in Duc Hoa District, Hau Nghia Province. In cooperation with the 2nd Bn, 14th Inf, numerous daily operations were launched and the results were as follows: 6 VC KIA, 6 VCI PW's, 1 60mm mortar w/base plate, 3 AK-47's 2 anti-tank mines and a VC SOI were captured.

(b) April yielded an influx of Hoi Chanhs, as the VCI team continued to harass the Duc Hoa infrastructure. Thirty VC rallied to ARVN outposts in Duc Hoa and Hoc Mon, and two surrendered to MID personnel. In addition to this, the following results were obtained in the field: 11 VC PW's, 5 VC KIA, 3 AK-47 rifles, 1 M-16, 2 pistols and 2 RPG launchers captured.

to ASR control during the reporting period. It is significant to note that an average of ten of these munitions required a minimum of one supplemental allocation each month in order to sustain tactical operations. High dollar / high tonnage items (i.e. 81mm HE, 4.2” HE, and artillery rounds) were the principal munitions under management control, in addition to 40mm HE, signal flares (white star parachute), and 2.75” rockets.

(2) (C) The division received thirty (30) M551 Sheridan vehicles during the period. Twenty-seven (27) were assigned to the 3rd Squadron, 4th Cavalry, and three (3) as maintenance floats. Training culminated with the squadron's tactical employment of the vehicles on 23 February. The training program prior to deployment, was conducted by the New Equipment Training Team and technical representatives. The vehicle test phase was monitored by the Army Concept Team in Vietnam (ACTIV).

(3) (C) XM-706 Commando Cars were issued to the division in late March. The initial issue was three (3) vehicles followed by two (2) more during April. Five (5) additional vehicles are due to arrive in the near future. All vehicles were issued to the 25th Military Police Company for convoy escort duty.

(4) (C) In an attempt to identify all reportable equipment, the division established a density list. This list, normally a function of the maintenance battalion, is maintained by the G4 section and has proven an effective management tool at the division level. Copies of the monthly list are furnished USARV-II Field Force, 79th Maintenance Battalion (GS), 94th Maintenance Company (DS), and the 72ND Maintenance Battalion (DS).

(5) (C) The Periodic Logistics Report was discontinued by USARV. Items that had appeared on this report will be entered on the bi-monthly Commander's Critical Items List (CCIL). The two reports were a duplication of effort in various areas; therefore, they were combined. The following statistics are a recap of the 25th Infantry Division's CCIL reported as of 30 April, 1969.

(8) (C ) Throughout the reporting period, the 25th Division Support Command Headquarters elements and subordinate units have participated in Operation TOAN THANG, Phases II and III, by supporting the operation from the facilities located at Cu Chi, Dau Tieng, Tay Ninh and Duc Hoa, as well as providing logistical support to the Naval operations at Go Dau Ha. Support Command also continued its responsibility for base camp defense at Cu Chi Base Camp until 20 March 1969. On 20 March the base camp defense was transferred to the 2nd Brigade.

(b) (C) Command emphasis was placed on the retrograde of salvage and CONEX containers, up-grading the living conditions in all areas of the Support Command, and management of resources. Increased command and staff visits to supported units greatly assisted in up-grading the supply, maintenance, and ammunition status of the Division.