Battle of Kham Duc

The Battle of Kham Duc was a major battle of the Vietnam War (also known, in Vietnam, as the "American War"). The event occurred in Khâm Đức, now district capital of Phước Sơn District, then in Quảng Tín Province (now part of Quảng Nam Province, South Vietnam), between 10–12 May 1968. During the Tet Offensive of 1968, the Vietnam People's Army (PAVN) 2nd Division tried to capture Đà Nẵng but their attacks were quickly blunted by elements of the U.S. 1st Marine Division, the Americal Division, and the Korean Brigade that were guarding the city. North Vietnamese General Chu Huy Mân decided to disengage from the fight in the outskirts of the city, and pull the 2nd Division into the mountains where they could rest, rebuild, and prepare for the next major operation. Khâm Đức, a small district in the north of Quảng Tín, was chosen as the next target for the PAVN 2nd Division. Following the defeat of the North Vietnamese in Đà Nẵng, U.S. military intelligence agencies in I Corps Tactical Zone were confused by the movements of the North Vietnamese 2nd Division, because they could not track down the mysterious enemy unit.

During March and April, U.S. military intelligence began to detect elements of the PAVN 2nd Division moving towards Khâm Đức, but their opponent's true intentions were largely unknown. In response to what could be a major attack, General William Westmoreland decided to build-up the defenses of the Khâm Đức Special Forces, by sending in U.S. Army engineers to upgrade the local airstrip for sustained use by large transport aircraft, as well as airlifting weapons and ammunition for the U.S.-led Detachment A-105. Australian-led 11th Mobile Strike Force (MSF) Company was ordered to take up positions in Ngok Tavak (Ngok Ta Vak), an outpost serving Khâm Đức, to boost allied intelligence-gathering capabilities in the area. However, unbeknownst to the United States and other allied forces, the Viet Cong (VC) 1st Regiment had been watching the build-up around Khâm Đức for some time, and were preparing to initiate the assault by taking out Ngok Tavak.

In the early hours of 10 May, elements of the VC 1st Regiment attacked Ngok Tavak, and they successfully overran much of the outpost. By dawn, the 11th MSF Company was devastated, but they later received reinforcements which came in the form of the 12th Mobile Strike Force Company. Despite having received assurances that further reinforcements would arrive to relieve the outpost, the commander of the 11th MSF Company decided to evacuate his troops and move towards Khâm Đức. By that time, however, the VC 1st Regiment had already turned their attention to the main target at Khâm Đức, and they only left behind some local force units to destroy allied reinforcements. Meanwhile, elements of the Americal Division had been airlifted into Khâm Đức as part of Operation Golden Valley, to bolster the strength of the Special Forces Camp there. On the morning of 11 May, the North Vietnamese 2nd Division surrounded Khâm Đức, and they gradually forced United States-led forces into their bases after several outposts were overrun. Westmoreland then ordered Khâm Đức to be evacuated, so the 834th Air Division was told to make an all-out effort to extract all the people in Khâm Đức, both military and civilian. By the time the evacuation was completed, nine U.S. military aircraft had been shot down, including two C-130s. On 12 May, the North Vietnamese were in complete control of Khâm Đức. The battle was a major defeat for the U.S. military.

Background
1968 marked a decisive turning point in the history of the Vietnam War. Towards the end of January, regular units of the Vietnam People's Army and the Viet Cong (VC) initiated large-scale attacks on Saigon and all 34 provincial cities of South Vietnam. Several major towns, villages, and allied military installations throughout the country were also attacked during the same period. In doing so, the North Vietnamese and their southern VC allies violated the Tết holiday truce, which had enabled South Vietnamese military personnel to go on leave. Subsequently, the combined PAVN forces were able to achieve the element of surprise, and quickly gain ground in various parts of the country. Despite early victories, the PAVN could only sustain their offensive for several weeks, or a few months in parts of South Vietnam where they were closest to their bases in Cambodia and Laos. Ultimately, North Vietnamese and VC units were gradually driven out from Saigon and the provincial cities.

In I Corps Tactical Zone, the North Vietnamese military had mixed successes against allied military forces. On 7 February 1968, a North Vietnamese infantry contingent armed with satchel charges, tear gas, and flamethrowers, and reinforced with Soviet-made PT-76 amphibious tanks, successfully breached the wires of the Lang Vei Special Forces Camp. The combined American, South Vietnamese, and indigenous Civilian Irregular Defense Group (CIDG) personnel absorbed more than 300 casualties while trying to hold their positions. During the battle Lieutenant Colonel Daniel F. Shungel — Commander of Company C, 5th Special Forces Group — had to fight his way out of the camp in order to escape the North Vietnamese attack, until rescued by a relief task force led by Major George Quamo. At Khe Sanh, located about 7 km east of Lang Vei, the U.S. 26th Marine Regiment was able to hold their ground against a multi-division North Vietnamese assault. During the siege U.S. Air Force, Navy, and Marine fighter-bombers dropped 40,000 tonnes of bombs on North Vietnamese positions, while B-52 bombers unleashed more than 60,000 tonnes of ordnance on areas where the North Vietnamese were believed to have concentrated their forces.

In the same period, the PAVN 2nd Division under the command of General Giáp Văn Cương clashed with elements of the Americal Division, the U.S. 1st Marine Division, and the South Korean Brigade in their attempts to capture Đà Nẵng. However, due to mixed up signals between the PAVN 2nd Division and other VC units the North Vietnamese were defeated. After 9 February, the PAVN 2nd Division seemed to be withdrawing from the battlefield, so Lieutenant General Robert E. Cushman, Jr. Commander of III Marine Amphibious Force ordered his troops to continue their attacks on the retreating forces. In the aftermath of the battle for Đà Nẵng, U.S. military commanders in I Corps held different views on the fighting ability of the PAVN 2nd Division. Major-General Samuel W. Koster claimed losses sustained by the PAVN 2nd Division had "impaired its future effectiveness", after his units allegedly killed more than 1,000 enemy soldiers in the month of January alone. In contrast, Major-General Donn J. Robertson told his superiors that the 2nd Division may have several uncommitted units they could deploy for future operations, which was a threat to the remaining South Vietnamese units and a U.S. Marine battalion in the region that had sustained significant losses of their own.

Whether the PAVN 2nd Division had been rendered ineffective or not was uncertain, as U.S. military intelligence did not know the whereabouts of the enemy unit or their intentions. Since January 1968, the North Vietnamese had been fighting continuously with U.S. and other allied military forces in I Corps, so their resupply capabilities were overstretched, and their soldiers were not given the opportunity to rest before the Tet Offensive. Thus, following the failed attack on Đà Nẵng, North Vietnamese General Chu Huy Mân, Commander of Military Region 5, made the decision to pull the 2nd Division into the mountains where they could rest, resupply, and integrate their replacement manpower before going on the offensive again. Mân ordered Cương to split the 2nd Division into two fighting arms; one regiment would tie down the Americans in the Que Son Valley, while the rest of the division would withdraw to their base areas near Laos, to link up with the 70th Transport Regiment. Then, their next target would be Khâm Đức and the surrounding areas; Mân told his senior officers that they would attack Khâm Đức to force an American retreat.

Khâm Đức was situated in the northern section of Quảng Tín Province, South Vietnam, in I Corps Tactical Zone. It sat beside National Highway 14, which paralleled the international border with Laos, and it was surrounded by high mountains on all sides. The Special Forces Camp was named after the main village which was located about 800 m to the northeast, and was constructed about mid-way along a 6,000 foot asphalt runway. Before his assassination, President Ngô Đình Diệm had used Khâm Đức as a hunting lodge, so an airfield was constructed there for Diệm's use. The Khâm Đức Special Forces Camp was under the responsibility of Detachment A-105, United States Army 5th Special Forces Group; the camp functioned as a training centre for CIDG personnel, reconnaissance of enemy movements, and combat operations. The village had 272 inhabitants, most of whom were dependents of the South Vietnamese and Montagnard CIDG soldiers. Ngok Tavak, located about 7 km southwest of Khâm Đức, was an observation outpost for Detachment A-105. Following the loss of Lang Vei, Khâm Đức was the last remaining Special Forces camp adjacent to the Ho Chi Minh Trail in I Corps. In May 1968, both Ngok Tavak and Khâm Đức were overrun by PAVN forces and American, Australian and South Vietnamese forces had to retreat after being defeated.

Prelude
From their base area positioned between Highway 14 and the Đăk Mi river, elements of the PAVN 2nd Division were planning for their attack on Khâm Đức and the surrounding outposts. The VC's 1st "Ba Gia" Regiment — commanded by Lieutenant Colonel Nguyễn Văn Trí — was given the task of initiating the attack, including sweeping aside the small outpost of Ngok Tavak (Ngok Ta Vak). However, before the plan of attack was finalized, the VC remained hidden as to avoid detection by the South Vietnamese and their American allies. Consequently, during that period the GK.31 Anti-Aircraft Battalion was prohibited from opening fire on U.S. reconnaissance aircraft that flew over their area. At the same time, the GK.40 Engineer Battalion was told to conduct training on their new equipment, such as satchel charges, tear gas, and flamethrowers, before the deadline of early May 1968. The VC 1st Regiment Headquarters also made their preparations for the initial attack, by regularly sending out Local Force Montagnard units to conduct reconnaissance patrols around Ngok Tavak in order to observe enemy activities in the area.

Throughout March and April, allied intelligence was baffled by the movements of the units belonging to the North Vietnamese 2nd Division, and that was reflected in the information obtained by U.S. military forces. For example, the U.S. 1st Marine Division reported that the enemy's 2nd Division Headquarters, the 3rd Regiment, the 21st Regiment, and the VC's 1st Regiment were within the vicinity of Khâm Đức, Thượng Đức, and Hội An, respectively. In contrast, information released by the U.S. 27th Marines Regiment showed the presence of the 3rd and 21st Regiments near Goi Noi Island, whereas the 2nd Division Headquarters was reported to be in the Que Son Valley. Despite the lack of accurate information, allied intelligence generally agreed the North Vietnamese might begin attacking isolated outposts and units as their next course of action. Subsequently, on 4 May 1968, the Americal Division made amendments to their Golden Valley Plan, the plan for the relief and reinforcements of CIDG camps, to enable the deployment of the 1st Battalion, 46th Infantry Regiment, 196th Light Infantry Brigade to support Khâm Đức.



To counter a possible major North Vietnamese attack, the U.S. military began taking steps to reinforce Khâm Đức. Starting on 9 April, the U.S. 70th Engineer Battalion was flown in from Pleiku, about 160 km to the south, to repair and upgrade the airfield for sustained use by C-130 Hercules transport aircraft. By 8 May, the U.S. Air Force had airlifted about 400 tonnes of cargo into Khâm Đức, including two bulldozers, by a C-124 Globemaster. In addition, 33 U.S. Marines from Battery D, 2nd Battalion, 13th Marine Regiment were also deployed to support the defenders at Ngok Tavak. From 16 April, the Marines artillerymen used Khâm Đức as a staging area where they could assemble their entire detachment, which included two 105mm howitzers, ammunition, and supplies. On 4 May, 33 Marines, along with 35,380 kg of equipment and supplies, were lifted into Ngok Tavak by helicopters. Meanwhile, towards the end of April, the VC 1st Regiment received orders to leave their base and take positions in the valley on the western side of Ngok Tavak, and wait there until the attack signal was given. The 40th Battalion — commanded by Major Đặng Ngọc Mai — spearheaded the assault.

The outpost of Ngok Tavak was manned by the 11th Mobile Strike Force Company since March 1968. Earlier in the year, Company C, 5th Special Forces Group in Đà Nẵng came up with a plan to supplement the intelligence agencies in the Khâm Đức area, by deploying a Mike Force Company to operate south of the Special Forces Camp; subsequently, the 11th MSF Company was selected for the task. The unit was led by three members of the Australian Army Training Team Vietnam (AATTV): Captain John White and Warrant Officers Frank Lucas and Don Cameron. The Australian-led unit included eight U.S. Special Forces and 173 South Vietnamese and Nung CIDG soldiers, and they were joined by 33 U.S. Marines on 4 May. Since their arrival, White and his men had set up camp on top of the hill feature in Ngok Tavak. They also made improvements to the camp's defensive perimeter, which included an old minefield left by the French. Despite their preparations, in the days leading up to the battle, the unit was plagued by a number of problems with their defense.

Even though the Marine artillerymen of the 2nd Battalion, 13th Marines Regiment were supposed to support the Ngok Tavak garrison, their arrival created significant logistical issues for Captain White. Due to the poor condition of the road that connected Ngok Tavak and Khâm Đức, where most of the ammunition was stocked, the Marines had to rely on transport aircraft to bring in ammunition supplies. However, due to high demand and scarce resources, the U.S. 1st Marine Aircraft Wing simply did not have the flexibility to provide the support required by the soldiers at Ngok Tavak. Furthermore, only 31% of the Marines' heavy-lift aircraft was available for operations. The lack of logistical support was exemplified by the manner in which the 105mm howitzers were deployed; when the Marines arrived at Ngok Tavak, White ordered the Marine detachment to place their howitzers on a downhill position outside the camp's perimeter, as the hill-top position was still covered by trees, making the position of the howitzers a non-ideal location for security.

In an effort to bolster the strength of White's 11th MSF Company, Shungel sent a mortar platoon of about 35 Montagnard CIDG out from Khâm Đức to reinforce the small garrison at Ngok Tavak during the last days of April. It was intended that the Montagnards would provide local security for the garrison, when the 11th MSF Company was out on patrol. Mistrust developed between White's men and the Montagnard soldiers, because the latter was known to contain VC infiltrators. On 28 April, elements of the PAVN 2nd Division received a message which stated that ‘scouts’ were ready to cause confusion and disruption in the allies' defensive plan around Khâm Đức. The Montagnards were placed outside the camp’s perimeter, where they roamed freely inside the Marines' area during the days before and after the arrival of the howitzers. On 9 May, the Montagnards decided to return to Khâm Đức, but shortly afterwards they turned back to Ngok Tavak, claiming they had been ambushed by an unknown enemy unit. White and his Nung soldiers were skeptical about the claim, as they believed the story about an ambush was a lie and that no real fighting had occurred. As a result, White insisted that the Montagnards stay outside his perimeter.

From early May, the VC's 1st Regiment began to tighten its noose around the Ngok Tavak position. On 6 May, a platoon-sized patrol from Ngok Tavak made contact with VC units about 1 km south of the garrison. On the evening of 7 May, enemy soldiers were believed to have set off trip flares, which prompted the Nung soldiers to hurl grenades at the perimeter. On 8 May, White ordered the Marines to pull their artillery guns inside the defensive perimeter, so they could better defend their position from the top of the 738 m-high hill feature. The Marines spent the entire evening of 8 May taking the first howitzer completely apart in order to take it up the hill. That night, enemy soldiers set off trip flares and again the Nung soldiers threw grenades in response. On 9 May, Captain Chris Silva flew to Ngok Tavak to discuss the reliability of his troops with his Australian counterpart, but was prevented from returning to Khâm Đức due to poor weather. On that day, the second howitzer was dragged into the garrison, so the Nungs and Marines both guarded the perimeter of Ngok Tavak. Infantry protection was provided by the 1st and 2nd Nung platoons, which held the eastern side of the garrison, while the suspect Montagnard CIDG soldiers guarded the eastern entrance. Overlooking them were some Marines of Battery D, 2nd Battalion.

The fight at Ngok Tavak
In the early hours of 10 May, the VC 40th Battalion of the 1st "Ba Gia" Regiment, reinforced by Local Force Montagnard units, moved into position and made final preparations for the attack on Ngok Tavak. Special assault squads were formed to breach the camp's perimeters, while the second squad would fan out to destroy key targets inside the garrison. White was alerted to the movements of enemy troops outside his perimeter, so he quickly organized his Nung soldiers and placed his troops on 50% alert. The Marine detachment — commanded by Lieutenant Bob Adams — was unable to operate their howitzers due to the lack of flechette rounds, which were designed for battery defense and anti-personnel fire. Shortly after 3 am, the suspect Montagnard CIDG soldiers approached the garrison from the eastern entrance, where they asked the U.S. Marine guarding the outer perimeter to let them through; as the Montagnards entered the perimeter, satchel charges were hurled at allied positions while VC soldiers lit up the perimeters with flamethrowers, marking the first double-cross of the battle.

The initial VC attack had split allied formations within the garrison; the 1st and 2nd Platoons of the 11th MSF Company were pushed away from the eastern perimeter, while the Marines were either alone or had organized themselves into small groups of two or three, but none were in contact with each another. Meanwhile, from inside his command post, White called in air-support which later came in the form of an AC-47 Spooky gunship, a modified version of the C-47 Skytrain equipped with 7.62mm General Electric miniguns for the support of ground troops. On the eastern side of the garrison, VC soldiers of the 40th Battalion continued to charge up the hill firing their AK-47 assault rifles. Simultaneously, other elements of the VC 1st Regiment probed the southern and western end of the garrison, now held by Captain White's 1st and 3rd Platoons, to test the strength of allied defenses in that part of the garrison. By that stage, however, most Nung soldiers had retreated from their positions on the eastern end of the garrison, while the U.S. Marines were pinned down around the perimeters. By 03:30, the VC had captured the Marines' gun position. Captain White was able to maintain contact with Warrant Officers Cameron and Lucas through telephone, but they could not coordinate their forces.

Although the VC held a greater portion of the Ngok Tavak garrison, particularly on the eastern side, their attack was stalled. After the 40th Battalion had overrun the command post, they tried to advance on the landing zone where allied soldiers had set up a strong position from fortified underground bunkers, which the VC had failed to detect in their previous reconnaissance patrols. At 04:20, an AC-47 gunship from the 4th Air Commando Squadron was reported to be flying over the garrison, so White directed the aircraft to fire down on VC-held positions around the perimeter. After he had shouted warnings to the Marines and the Nungs, White approved the aircraft to fire on the position area of the 105mm howitzers. The arrival of the AC-47 enabled the allied forces to hold their last remaining ground, and repulse the final attack. By 05:30, fighting in and around Ngok Tavak was limited to the hurling of grenades, and random fire on any movement that was believed to be that of the VC. In one of their final attempts to overcome the last allied position, the VC set off tear gas of such low density that it had little effect on most of the allied soldiers.

As events in Ngok Tavak unfolded, White sent urgent messages to Company C, 5th Special Forces Headquarters in Đà Nẵng, as well as to the Americal Division, to request support. In response, the 5th Special Forces Headquarters ordered Captain Eugene Makowski to fly to Khâm Đức, where he would assume command of the 12th Mobile Strike Force Company, to reinforce White's beleaguered soldiers at Ngok Tavak. Then, just before sunrise, Colonel Trí ordered the 40th Battalion to pull out of Ngok Tavak in order to deal with an enemy relief force, and leave behind only a blocking force to hold the captured positions inside the garrison. Following those events, Australian Warrant Officers Cameron and Lucas mounted a counter-attack using a handful of Nung soldiers in an attempt to retake captured positions. At that point, those Marines who had survived the main battle decided to join the fight, and as the Australian-led formation moved through the Ngok Tavak garrison, they gradually pushed the last remaining enemy soldiers beyond the defensive perimeter.

By early morning White had expected further assaults from the VC 40th Battalion, but his opponents had moved out towards Khâm Đức with the rest of the PAVN 2nd Division. Simultaneously, the AC-47 flying overhead continued to direct fighter-bombers against suspected Viet Cong positions around Ngok Tavak, but the garrison continued to receive sporadic mortar, RPG, and small-arms fire. In addition to close air support missions, medivac helicopters flew in to evacuate the wounded, and U.S. aircrews reported that they did not receive fire while flying over the enemy's area of operations. Captain Silva and Lieutenant Adams, who were both wounded during the main battle, were also evacuated. While the wounded were being flown out, the surviving elements of the 11th MSF Company and the Marines re-consolidated their positions, even though cohesion had broken down between the allied soldiers as a result of the double-cross that occurred earlier in the battle. At the same time, Makowski's 12th MSF Company had departed Khâm Đức and was approaching Ngok Tavak onboard four U.S. Marine CH-46 Sea Knight helicopters.

At around 09:30, the four CH-46 helicopters arrived in Ngok Tavak, and they were able to unload Makowski and about 45 soldiers of the 12th MSF Company. However, the VC demonstrated their domination of the landing zone when the first helicopter was hit with anti-aircraft fire, and was forced to land on the ground, intact, though with damages to the fuel line. Moments later, the third helicopter was struck by a rocket propelled grenade as it turned around to rescue the crews of the first downed helicopter, and it was destroyed immediately. Now, with two downed helicopters blocking the landing zone, the remaining helicopters were prevented from landing on the ground, so the wounded men had to be evacuated while the helicopters were still hovering. As the last helicopter took off, two Nungs and one stranded U.S. soldier grabbed the helicopter skids to get out of Ngok Tavak, but they all fell to their deaths. Shortly after his arrival, Makowski placed the 12th MSF Company under the command of his Australian counterpart, as the situation continued to worsen.

Because his Nung soldiers were exhausted, with their ammunition and water supplies running low, White believed they could not defend the Ngok Tavak garrison in case the VC launched another major attack. At 10:45, White requested permission to evacuate the garrison, but he was told to stay and wait for the arrival of reinforcements. However, both White and Makowski knew that reinforcement was unlikely, because the two downed helicopters would prevent the insertion of additional soldiers, and the road between Ngok Tavak and Khâm Đức was likely to be covered by the opposing forces waiting in ambush positions. White then decided to evacuate Ngok Tavak and withdraw his troops to safety. As part of the evacuation plan, any type of equipment that could not be taken or was considered to be of value to the opponent was dumped into the command bunker and set alight using captured enemy flamethrowers. The Marines were ordered to fire their last remaining shells, about nine rounds in total, after their ammunition storage was set ablaze by the VC, and disable their 105mm guns.

As White had expected the survivors to fight their way out of Ngok Tavak, he made the decision to leave the dead allied soldiers behind; the decision caused distress amongst the survivors of the battle, but White believed evacuating the deceased soldiers through enemy lines would have been suicidal. After the Marines and Mobile Strike Force personnel had destroyed their unneeded equipment, they were directed to form an order-of-march out of Ngok Tavak, in order to protect the wounded and those with little infantry experience. Just before they left the garrison, Cameron blew up the first CH-46 helicopter that was still intact on the landing zone, using the M-72 anti-tank weapon. The order-of-march was led by a group of Nung soldiers, who were followed by White and the survivors of the Marine artillery detachment, and behind them was another group of Nung soldiers covering the tail of the column. Together they evaded VC formations surrounding the hill feature of Ngok Tavak and marched eastward towards Khâm Đức.

About halfway between Ngok Tavak and Khâm Đức, White and the rest of the column climbed a mountain where they cleared the jungle to create a landing zone, and called for helicopters to evacuate the survivors. A flight of CH-46 Sea Knights later arrived and, in a scene that would be repeated at Khâm Đức, chaos descended on the allied formation as Nung and U.S personnel fought their way onto the helicopters. Some of the Nung soldiers had to be thrown off because the helicopters quickly reached their limit capacity; eventually U.S. aircrews had to dump some of their equipment overboard to accommodate the last remaining Nungs on the landing zone. By 08:00, the evacuation of the Ngok Tavak survivors was completed, and White immediately flew out to Đà Nẵng along with the two Australian Warrant Officers after they arrived in Khâm Đức. The fight at Ngok Tavak, though short in duration, took a heavy toll on the allied forces. An unknown number of Nung soldiers and 15 U.S. military personnel were killed, and 52 (including two U.S. Army and 21 U.S Marines) were wounded.

Kham Duc surrounded
At 02:45 on 10 May, in conjunction with the ground assault on the Ngok Tavak outpost, elements of the VPA 2nd Division subjected Khâm Đức to a heavy barrage of mortar fire. The North Vietnamese  21st Regiment, later reinforced by the VC 1st Regiment, were in position to attack the U.S.-led Detachment A-105. At 08:30, the Americal Division activated Operation Golden Valley to reinforce the beleaguered Khâm Đức Special Forces Camp, and at 8:45 am the division requested permission from III MAF to change the reaction force so the 2nd Battalion, 1st Infantry Regiment, 196th Light Infantry Brigade (2–1st Inf) would replace the 1st Battalion, 46th Infantry Regiment, 198th Light Infantry Brigade (1–46th Inf). In the meantime, however, Company A of 1–46th Inf provide the needed reinforcement, until the 2–1st Inf was in position. At around 10:50 Company A of 1–46th Infantry — led by Lieutenant Bobby Thompson — arrived in Khâm Đức along with some supporting artillery and ammunition, and they were immediately assigned to their task. . Thompson's company dug in at the end of the runway nearest OP 1 with XO Peter Everts' platoon overlooking the deep ravine where caves kept the NVA from harm due to B-52 strikes called in on their location. Everts recalls being lifted off the ground near his runway CP by the B52 strikes.<ref name=Everts).

About six hours later, the 2 Battalion/ 1st Infantry — commanded by Lieutenant Colonel Robert B. Nelson — also touched down on the battlefield, and they immediately set up defensive positions in support of Detachment A-105. Under constant enemy mortar and artillery attacks, U.S. and allied forces were able to strengthen their defenses, because there were no significant ground probes during the period between 10–11 May. Allied defenses at Khâm Đức remained thin and the North Vietnamese had occupied the high ground in the surrounding hills, where they could target allied ground targets and support aircraft with a high level of accuracy. On 11 May, in response to increasing North Vietnamese pressure, about 30 B-52 Stratofortress bombers were called in to hit North Vietnamese-held positions, but those strikes had little effect as artillery and mortar rounds continued to fall on Khâm Đức and the surrounding outposts. Consequently, Cushman recommended to Westmoreland that Khâm Đức, now defended by more than 1,500 allied soldiers along with 272 civilians, be evacuated. Westmoreland agreed, believing that Khâm Đức lacked the “defensive potential of Khe Sanh”.

By 01:00 on 12 May, U.S. commanders on the ground in Khâm Đức were notified of Westmoreland's decision to evacuate all military personnel, both American and Vietnamese, as well as their civilian dependents. However, most army units on the ground were left uninformed about the decision, and it led to chaos later when evacuation was underway. During the predawn hours of 12 May, elements of the PAVN 2nd Division continued to increase their pressure on the main compound of the Special Forces Camp. The North Vietnamese made final preparations for the main assault by capturing one mountain outpost at a time, which were manned by U.S. soldiers of the Americal Division, who had placed machine-guns around the main camp as advanced defensive positions. At 04:23, U.S. soldiers reported that outpost number 1 had been overrun, and fighter-bombers were scrambled in an attempt to save it. About 30 minutes later, the defenders of outpost number 7 reported that their position had been surrounded. They attempted to hold their position by calling on an AC-47 gunship to fire directly into their position, in order to stop the attack, but soon afterwards outpost 7 succumbed to the North Vietnamese and the defenders retreated back to Khâm Đức.

U.S. soldiers at outpost number 3 called on supporting artillery units at Khâm Đức to fire directly at their own position in an attempt to hold off the North Vietnamese, but they too were defeated a few moments later. Before sunrise, all seven outposts were firmly in North Vietnamese hands, so U.S. and allied soldiers were placed in a perilous position. The North Vietnamese had occupied all the high ground, from which they could fire down on any support aircraft that tried to resupply the camp or to evacuate people from it. By sunrise, the North Vietnamese moved closer to the Special Forces Camp under the cover of the early morning fog. About one hour before the fog was lifted, an additional 24 B-52 bombers flew in and dropped several hundred tons of bombs on suspected North Vietnamese positions south of Khâm Đức. At 08:20, General Burl W. McLaughlin — commander of the 834th Air Division — was ordered by the U.S. 7th Air Force to make an all-out effort to evacuate the besieged Special Forces Camp at Khâm Đức. By 09:35, the B-52 strikes had clearly failed to stop the North Vietnamese advance, when the camp's south-eastern perimeter was subjected to a massive ground assault.

To stop the opponent's onslaught, U.S. fighter-bombers were called in to strafe North Vietnamese and VC formations, while U.S. soldiers on the ground used small-arms and artillery fire to break up the attack at point-blank range. Meanwhile, a U.S. Army UH-1 Huey and an O-2 Skymaster were shot down while circling the compound. By the time the first attack was stopped, the opposite end of the compound also came under fire, and by early morning tactical air-support became difficult, as North Vietnamese troops were in close proximity with U.S. and allied forces. A U.S. Army CH-47 Chinook then arrived to begin the process of evacuation, but it took several hits from anti-aircraft fire. The helicopter then burst into flames, exploded, and blocked the runway. U.S. soldiers of the 70th Engineer Battalion first tried to remove the wreckage with a forklift (their only operating vehicle, the bulldozers having been disassembled in preparation for airlift out); the forklift caught fire from the burning plane, and the engineers then assembled one of their bulldozers to push the downed helicopter off the runway; North Vietnamese troops mortared the bulldozer but SP5 Don Hostler cleared the wreckage and then tracked the dozer back into Camp Conroy and shut it down. By 10:00 they had cleared the obstacles which would prevent other fixed-wing aircraft from using the airfield. Almost simultaneously, a single U.S. Air Force A-1 Skyraider flown by Lieutenant Colonel James N. Swain Jr. was shot down outside the camp perimeter.

The unfolding events seemed to have a negative impact on the cohesion between U.S. and South Vietnamese indigenous forces. The resolve of the South Vietnamese, Montagnard CIDG soldiers in particular, had apparently been shaken and they disobeyed an order to carry out a sweep operation at the rear end of the camp, and their Vietnamese commander even refused to leave his bunker to encourage the soldiers. The morale and discipline of the indigenous forces had sunk so low that they began to leave their defensive positions without permission, although their section of the camp was never subjected to a major ground attack. Consequently, the behavior of indigenous CIDG soldiers during the various stages of the battle, coupled with information that ‘friendly’ Montagnard soldiers had turned on U.S. Marines at Ngok Tavak, had the effect of unnerving U.S. Army soldiers in Khâm Đức. To ensure CIDG soldiers would not abandon their posts, U.S. soldiers threatened to shoot anyone attempting to run away.

Evacuation
At approximately 10:00, the runway at Khâm Đức was cleared of the wrecked helicopter. Moments later, a C-130 piloted by Lieutenant Colonel Daryl D. Cole touched down on the runaway under heavy fire, which flattened one tire and caused extensive damage to the wing tanks. Almost immediately, Cole's aircraft was rushed by hysterical Vietnamese civilians from ditches along the runway, filling the aircraft so the loadmaster was prevented from unloading the aircraft's cargo. Under heavy fire, Cole decided to navigate his aircraft down the cratered and shrapnel-littered runway, in order to take off. However, the combined weight of the cargo and civilians, in addition to the damage sustained during landing, prevented the aircraft from gathering enough speed to take off. So the aircrew aborted the take off, offloaded the civilians, and proceeded to cut off the blown tire to stop it from flapping and slowing down the aircraft. They were able to cut off the rubber with the bayonet, and were able to cut through the steel beading thanks to the engineers carefully cutting the steel cords with a blowtorch. A fire extinguisher was kept handy because of fear of catching the magnesium wheel on fire. About two hours later, realizing that enemy artillery rounds were coming closer to his aircraft, Colonel Cole tried to take off for the second time, and managed to get the C-130 into the air. This time his only passengers were three members of Air Force Combat Control Team (CCT), whose radio equipment had been destroyed. Just after Cole's C-130 left Khâm Đức, a C-123 flown by Major Ray D. Shelton landed and took out 44 U.S. engineers and 21 South Vietnamese civilians. Shortly after Shelton had landed his aircraft, he reported that enemy fire was coming in from all quadrants, but he was able to take off safely after just three minutes on the ground. By 11:10, just 145 people had been evacuated by Shelton’s aircraft, and a handful of helicopters. After that, another three C-130s also arrived in the vicinity of Khâm Đức, but the pilots were told not to try landings. In the afternoon, the C-130 Hercules resumed their operations; at 15:25, Major Bernard L. Bucher's C-130 approached Khâm Đức's airfield from the south and landed despite taking numerous hits. Some 150 Vietnamese women and children rushed onto the aircraft; as soon as the aircraft was full, Bucher made his takeoff in the north direction, unaware that opposing forces were concentrated in that area. At 15:30 Bucher took off, and his aircraft was quickly riddled by ground fire; it crashed less than a mile from the end of the runway. All the South Vietnamese civilians and the entire U.S. aircrew died in the crash.

With the loss of Bucher and his aircraft, the C-130 Hercules had not completed a successful evacuation, and there were more than 600 people still on the ground. Next in line was Lieutenant Colonel William Boyd; he was flying an airlift mission into Chu Lai, until he was diverted into Khâm Đức to extract forces and civilians there. Just before Boyd touched down, an artillery shell exploded about 100 feet in front of his aircraft, so he was forced to pull the throttle forward. Boyd then pulled up and went around for a second approach, because he could see the desperation of the people on the ground. As he landed, hundreds of civilians and soldiers poured out of the ditches and rushed onto the aircraft. Because he had witnessed the destruction of Bucher's C-130 while taking off in the north direction, Boyd decided to fly out from the southwest. After Boyd's aircraft was airborne, he banked the aircraft so it would be masked by the rolling terrain. The aircraft sustained damages to the left wing, the fuselage, and the leading edge of both wings, but it landed safely in Chu Lai with all the passengers.

As Boyd took off, another C-130 piloted by Lieutenant Colonel John Delmore closed in on Khâm Đức. At an altitude of about 300 to 400 feet, Delmore's aircraft began to receive North Vietnamese fire, and both sides of the cockpit were opened up by bullets that had ripped through the floorboards. Subsequently, just before touch down, Delmore and his co-pilot shut down the engine and forced the aircraft to remain upright. With no brakes and little directional control, the aircraft crashed into the CH-47 that had been destroyed early in the morning, but Delmore managed to turn his aircraft off the runway to avoid blocking it. When the aircraft had stopped completely, the five-man crew got out as quickly as they could. About 20 minutes later, U.S. soldiers on the ground guided them to safety, and they were rescued by a U.S. Marine CH-46. After witnessing the destruction of two C-130 Hercules, Lieutenant Colonel Franklin Montgomery landed his C-130 and extracted more than 150 Vietnamese civilians, and some CIDG and U.S. soldiers. Montgomery's aircraft suffered no hits, but the loadmaster was knocked down and trampled by panic-stricken Vietnamese civilians whilst trying to maintain order.

Once Montgomery had flown out, another two C-130s arrived in Khâm Đức to continue the evacuation; the first aircraft picked up 130 people, and the one after that took out 90. There were now only a few people remaining on the ground in Khâm Đức, and most of them were U.S. Special Forces soldiers and indigenous CIDG personnel. Major James L. Wallace flew into Khâm Đức and extracted the last group of people, as the ammunition dumps began to explode, and the aircrews reported witnessing hysteria among the Vietnamese soldiers who had lost family members in Bucher's crash. However, just when the aircrews believed the mission was over, a C-130 piloted by Lieutenant Colonel Jay Van Cleeff was ordered to reinsert the three-man Combat Control Team, which had been airlifted out of the compound earlier in the day by Colonel Cole. In protest, Van Cleeff argued that the camp was almost completely evacuated, but the control center insisted that the Combat Control Team be reinserted to complete their task of coordinating the evacuation. At about 16:20, Van Cleeff landed his aircraft on the runway and the Combat Control Team — led by Major John W. Gallagher — immediately disembarked from the aircraft.



After Gallagher's team had returned to the Special Forces Camp, Van Cleeff waited on the runway for two minutes to extract the survivors, but when nobody appeared he pulled the throttle and took off. As soon as Van Cleeff's aircraft was airborne, another C-130 pilot reported to General McLaughlin that the evacuation had been completed, and the facility could now be destroyed at will. Van Cleeff quickly notified all aircraft in the vicinity that he had just reinserted the CCT. Gallagher’s team searched the Special Forces compound, the Americal Division battalion command post, and the artillery compound, but everybody either had been evacuated or was dead. Additionally, Khâm Đức was in North Vietnamese hands, so Gallagher and the other two men ran to the ditch beside the runway, where they tried to make contact with the aircraft overhead, but the radio was disabled along with all other equipment. While waiting for a miracle, members of the CCT clashed with North Vietnamese troops who had set up a machine gun position beneath the wing of Delmore's crashed C-130, and successfully disabled their opponent's weapon.

During the ordeal, several forward air-controllers were sent out to make low passes over Khâm Đức, to locate the position of the CCT, but none were successful. Then, in response to a call for the nearest aircraft to land on the runway to search for the stranded members of the CCT, Lieutenant Colonel Alfred J. Jeanotte approached the airfield from the south and landed his C-123 on the runway with support from fighter-bombers, which were used to suppress enemy fire. Not seeing the men, Jeanotte applied full power and took off to avoid taking hits from North Vietnamese anti-aircraft fire. As the C-123 rolled past the CCT's position, the three men came out of their position chasing the aircraft with their arms waving. Believing that the aircraft may have missed them, the three men ran back to the ditch on the left side of the runway. As the C-123 was airborne, Jeanotte banked his aircraft to the left, and that enabled the aircrew to see the three men running back towards the ditch. However, Jeanotte was deterred from making another attempt at landing, because of low fuel. The next C-123 in line, piloted by Lieutenant Colonel Joe M. Jackson, landed on the runway as fire swept through the Khâm Đức facility, and the aircrew were able to extract the stranded CCT under heavy fire, and they flew out to Đà Nẵng. By 17:00, the evacuation was over. On 13 May, 60 B-52s bombed the Khâm Đức camp.

Aftermath
The battle for Khâm Đức and Ngok Tavak was considered a defeat for U.S. forces, described by one historian as "a Khe Sanh in reverse." Unlike the previous fight at Khe Sanh, the application of American airpower "averted a massacre" but could not prevent the North Vietnamese from dominating the high ground surrounding Khâm Đức. General Creighton Abrams described the loss at Khâm Đức as a "minor disaster". U.S. decisions at Khâm Đức may have been influenced at a higher command level by the events of Battle of Khe Sanh in 1968, which were subjected to intense media comparison with the French defeat at Dien Bien Phu, and the clash of operational thinking between General Westmoreland and the senior USMC generals. If there was any lesson to be learned for General Westmoreland and other U.S. commanders, the battle of Khâm Đức showed that "air power was not a cure-all". The command and control system of the United States Air Force during the ordeal was imperfect, as demonstrated by the "blunders involving the combat control teams." A final, notable outcome of Khâm Đức was that it closed the last Special Forces CIDG camp in the I Corps Tactical Zone in close proximity to the border with Laos. This made ground surveillance of the Ho Chi Minh Trail much more difficult, allowing North Vietnam to move supplies and develop new branches of the trail. Despite setbacks, the evacuation of the Khâm Đức Special Forces Camp strongly highlighted the morale, discipline and the motivation of the U.S. Air Force personnel who took part in the operation. From the very first day of the struggle at Khâm Đức, it was clear that ground units were not prepared for an emergency evacuation, due to the lack of experience in terms of integrating the numbers and types of aircraft in such a small geographical area. U.S. aircrews had to improvise by establishing their own procedures, in order to extract both military and civilian personnel from the besieged Special Forces Camp. Despite having lost two    C-130 aircraft, U.S. pilots were undeterred from completing their mission, indeed, their bravery was exemplified by Lieutenant Colonel Joe M. Jackson, who received a Medal of Honor for the rescue of the three-man Combat Control Team.

The U.S. Army lost many soldiers killed in action and 71 wounded at Khâm Đức and the U.S. Marines lost 12 marines killed in action and 21 wounded at Ngok Tavak. The combined services reported the highest number of missing in any battle in Vietnam, with 31 U.S. military personnel reported missing in action. Of the 31 MIA, 19 were from the 2/1st Infantry: of these 3 were rescued within 5 days, 1 was captured and kept as a POW until March 1973, and 15 listed as KIA (9 recovered, 6 not recovered). The U.S. lost 9 aircraft: 7 within the vicinity of Khâm Đức and 2 helicopters in Ngok Tavak. The North Vietnamese, however, claimed to have killed about 300 American soldiers and captured 104 enemy troops, including two American advisors, as well as capturing vast quantities of weapons and ammunition that were left behind. For South Vietnam, several hundred South Vietnamese Special Forces and indigenous CIDG soldiers were believed to have been killed, as well as about 150 civilians who perished in Major Bucher's crash. The total number of North Vietnamese casualties is unknown, but the United States military claimed to have killed roughly 345 enemy soldiers.

In July 1970, troops from the 196th Infantry Brigade reoccuppied Khâm Đức as part of Operation Elk Canyon I and II to disrupt North Vietnamese logistics system in Quang Tin Province and forestall a VPA offensive in the autumn and winter.

August 3, 1970, USAF Combat Control Team from 8th Aerialport Squadron again managed fixed-wing communications at Kham Duc. USAF CCT SSgt David Gfeller was WIA by RPG fire. 8th APS sent in a replacement for SSgt Gfeller after he was medevaced. By late evening, SSgt Gfeller had made his way back to 8th APS HQ barracks at Tan Son Nhut.

While they occupied Khâm Đức U.S. forces conducted searches for the remains of the Americans MIA in the battle two years earlier. In 1993–94 teams from the Joint POW/MIA Accounting Command located the Bucher crash site and recovered the remains of the six crewmen, the remains were buried together at Arlington National Cemetery in December 2008.