As February drew to a close, the ARVN I Corps commander assessed his situation. His main thrust was no longer viable, his right flank had disintegrated, but the PAVN attack had lost its momentum and under heavy pressure from the air had not been able to deliver a crushing blow from the north that could carry beyond Highway 9. The 1st ARVN Infantry Division was intact and relatively undisturbed on the south, and he had the Marine Division in reserve at Khe Sanh. Aviation assets were largely intact. The OH-6’s and OH-58’s had been withdrawn as scouts because they were too vulnerable in the 12.7 rich environment, but the scout role had been taken over by groups of 2 – 6 Cobra’s working with a C in C UH-1H and were very successful, their speed and agility allowing them to avoid the NVA AA fire.
The NVA tanks were a threat in being, but whenever they were spotted the reaction was swift and violent. One round fired by B Battery, 2/94 landed between two PT76’s and flipped them both upside down. When the air cavalry encountered tanks for the first time, high explosive antitank (HEAT) rockets were not available, so what was used was whatever ordnance was on board. The Cobra gun-ships opened fire at maximum range, using 2.75-inch flechette rockets to eliminate enemy troops riding on the outside of the tank and to force the crew to close the hatches. As the gun run continued, high-explosive and white phosphorus rockets and 20-mm. cannon fire were used against the tank itself.
PAVN T-54 knocked out on QL9
Eventually HEAT rockets became available, but they were not always effective. Although these rockets were capable of penetrating armor plate, they could do so only in direct hits. Engagements therefore had to take place at ranges of 900 to 1,200 meters, distances that exposed the gunship to the tank's heavy machine gun and to supporting infantry weapons. Between 8 February and 24 March, air cavalry teams sighted 66 tanks, destroyed 6, and immobilized 8. Most of the tanks, however, were turned over to fixed wing aircraft, which could attack with heavier ordnance.
The collapsed northern flank had served its purpose in giving early warning of large PAVN units on the move toward Highway 9. NVA tanks had been unable to close with the 1st Armored Brigade but the brigade in its present position was nothing more then static pillboxes that themselves needed to be protected. The brigade was strengthened with additional units as they became available including three companies of tanks, however, the reinforcement was so piecemeal that it was difficult to tell just who or what was committed. Many units never reached Aloui and simply plugged up the withdrawal. Only one-third of the cavalry squadrons and two-thirds of the tank squadrons available to I Corps were used in Laos, amounting to five tank squadrons and six armored cavalry squadrons total.
As the I Corps commander reviewed the situation at the end of February, withdrawal seemed premature without another attempt on the objective, so the Marine Division was moved into locations vacated when the 1st ARVN Infantry leapfrogged toward LZ Hope. One incident that may or may not have influenced his decision was that the BBC had already announced South Vietnamese troops had occupied Tchepone.
On 2 March, the 7th Marine Battalion, 147th Brigade, was inserted into Fire Support Base Delta. Over the next three days, the 147th Brigade Headquarters and the 2d and 4th Battalions were also brought into Delta. During this same time the 258th Brigade was inserted at FSB Hotel.
The first part of the assault on Tchepone required the 1st Battalion of the 1st Infantry Regiment to be inserted at Landing Zone Lolo, 13 kilometers southeast of Tchepone on 3 March. Twice the landing had been postponed and twice additional prep fires were brought in to suppress NVA fire on the LZ itself. Finally the NVA were driven out of their trenches, retreating west. Still the landing was very hot with 11 helicopters shot down and 44 others damaged by ground fire. Once the LZ was secure, 105 mm howitzers were airlifted in. On 5 March, troops were assaulted into LZ Sophia to protect the south flank of the main attack. The LZ was well protected by anti-aircraft up to 23 mm and the helicopters suffered, with three shot down on the first lift.
HITCHIN A RIDE - Downed aircrew on LZ LOLO taking cover in an NVA trench
This is the ride they came in on
The morning after, a Chinook drops a 105 at the purple smoke. I think there are at least 6 downed aircraft in the picture. One would be recovered.
Long final to LZ SOPHIA, another bad place.
6 March would be the day for the final assault into Tchepone. Prep fires for the assault included everything from B-52s to the 175’s at Lao Bao. B-52’s literally blew the tops off of mountains revealing underground storage facilities. U.S. tactical air strikes or air cover sorties were scheduled every 10 minutes. One hundred twenty U.S. helicopters assembled at Khe Sanh but were forced to depart 90 minutes earlier then planned because of incoming fire, however, preparations for this part of the operation had been so carefully planned that no problems resulted and when the first aircraft dropped off the 2/2 Battalion at Landing Zone Hope, four kilometers northeast of Tchepone, only incidental gunfire was encountered.
The North Vietnamese had not anticipated such a move and could not react quickly enough to stop it. By nightfall, 276 helicopter sorties (some aircraft making three trips) had landed about 5,000 ARVN troops against a loss of seven helicopters.
Tchepone itself was just a small village but around it the PAVN had established sanctuary base 604, the main base for attacks in Quang Tri Province, and base 611, south of 604 and closer to the border, used to launch attacks against the city of Hue and Thua Thien province. These base areas consisted of many small storage depots and five large storage areas, each between 1 to 2 square kilometers, stocked with weapons, ammunitions, logistic supplies, medical supplies and rations. Other areas around Tchepone were used for troop replacement and training. For a week ARVN troops wandered about the two base camps methodically destroying everything in sight or using artillery, tac air or gunships to destroy the depots. Over 9,700 secondary explosions were documented, sometimes continuing for a half hour after the initial strike. The NVA were in a state of shock at Tchepone, over 5,000 were killed in the depot area - mostly rear area troops or troops in rest centers - with another 69 captured as air cavalry roamed the area unopposed. Thousands of tons of enemy supplies were destroyed and a POL pipeline was cut in several places. Almost 4,000 captured enemy weapons were airlifted out and brought back to Viet Nam.
As the ARVN troops began moving down Route 914 to the south, the PAVN forces finally began to react and started putting up stiffer resistance each successive day as the NVA 2cnd Division moved north. Generals Abrams and Weyand saw a tremendous opportunity to strike a mortal blow, with the exception of the 2cnd Division, PAVN units were being withdrawn from the battle area, there was no general reinforcement of 70B Corps. Abrams tried to get President Thieu to commit the 2cnd ARVN Division into Tchepone to create what they saw as the only single decisive battle in the entire war, and one that could cripple the PAVN so badly the war might be won. Thieu agreed about the strategic possibilities but settled the question with one statement, he wanted a U.S. division to go also. With the current political climate in the U.S., both knew it would never happen, and so was squandered the possibility of cutting the jugular of all NVA operations in the south. Even though the I Corps commander had control of the 2cnd Division, he would not make the move without Thieu’s approval, so he waited while his corps was becoming ever more endangered. Finally, Thieu’s response was to order a withdrawal.
The withdrawal began from positions around Tchepone and Sophia West overland to LZ Liz. Two battalions and the 2cnd Regiment CP were extracted to FB Sophia East and then on to FB Delta 1. The next day two more battalions moved to LZ Brown. The 1st Regiment continued operations in base area 611 southwest of LZ Lolo while the 3rd Regiment worked southwest of Delta1 and LZ Brown.
PAVN forces were still not organized enough to contest these evacuations but it would be a different story four days later when it was time to evacuate LZ LOLO. The NVA had almost an entire division in place at LOLO to confront the three battalions of the 1st Infantry Division that were being evacuated. The evacuations continued and the attacks grew in intensity until finally the only troops left were 420 men of the 4th Battalion. Over the next two days this unit was reduced to 88 men taking cover in a ravine and commanded by a sergeant. Finally, on the afternoon of 18 March, the last 36 battered survivors were pulled from the LZ.
LZ Sophia East, also known as Sophia II, located east of LOLO was to be evacuated on 20 March. The U.S. Air Force and Army helicopters flew 1,388 gunship sorties, 270 tactical air strikes and 11 B-52 missions dropping 909 tons of bombs, and by 1300 hours, the 3d Battalion, 2d Regiment, 1st Infantry Division was extracted and taken to Khe Sanh. Twenty eight of the 40 helicopters involved in the lift were hit. A short distance away, the 4/2 Battalion was left on the ground when the lead helicopter in the flight was hit by fire and exploded in the air causing the evacuation to be aborted. The 4/2 was later evacuated under fire from LZ Brown.
On 18 March it was discovered that the NVA were gathering a regimental size unit northwest of Aloui, so the 1st Armor Brigade was ordered to withdraw by the I Corps commander. To cover the withdrawal, he allocated two U.S. air cavalry troops to the airborne division. It was at this point that the most severe command difficulties within the ARVN came to light. The 1st Armor Brigade had been placed under the control of the airborne division, but the division had no idea what to do with the armored troops and often they were left to fend for themselves. The airborne division commander was senior to the I Corps commander and was extremely miffed about the situation, even refusing to attend command briefings. And President Thieu tolerated the situation. So as the 11th Armored Cavalry Regiment acting as rear guard to the 1st Armor Brigade abandoned Aloui, no air cav was to be seen. The air cav had been ordered to support airborne battalions in other locations.
Between Aloui and Landing Zone Alpha, the armored column was ambushed at a stream crossing and four M41 tanks were abandoned in the middle of the stream isolating the 11th Armored Cavalry on the west bank. The airborne soldiers abandoned the cavalry and kept on marching east down QL 9. No reinforcements were sent and no recovery vehicles came to remove the abandoned tanks. The 11th fought on alone, and after three hours cleared a way across but had to leave seventeen disabled vehicles on the west side of the stream. The NVA used the vehicles as machine gun positions until the vehicles were destroyed on 25 March.
On 20 March the armor brigade reached Landing Zone Alpha, regrouped, and moved on. Still no air cavalry. The next morning the hapless 11th Armored Cavalry was leading when the brigade was ambushed three kilometers east of Fire Support Base Bravo. Air strikes were called in, one accidentally hitting the South Vietnamese with napalm, killing twelve and wounding seventy-five. The brigade pulled back west to regroup and were informed by a prisoner that two North Vietnamese regiments were waiting in ambush farther east. Less then 5 kilometers from South Vietnam, the column turned south abandoning the road. Unknown to them, the airborne division had combat assaulted troops north of the ambush and cleared it. The armor column was never informed that the road was clear and after two difficult river crossings and a 17 kilometer detour cross country, finally reached South Vietnam and linked up with the U.S. 1st/ 77th Armor. A MACV advisor to the Armored Brigade met the column at the border and counted the vehicles, 25 out of 62 tanks and 64 out of 162 APC’s returned; the totals included those vehicles added as reinforcements . Sadly, most had not been combat loss, they had broken down or ran out of gas and been abandoned.
The next day, the 1st Armored Brigade and a paratrooper battalion were ordered to go back and recover the 17 damaged tanks and APCs left behind by the 11th Cav. Once again American air cover had been promised and once again it was diverted. The brigade succeeded in picking up the vehicles and had the 17 vehicles in tow when, once again, they were ambushed crossing a river near Aloui. The four lead M-41 tanks were hit with RPG’s blocking the route. For three hours the South Vietnamese fought to survive until the disabled tanks were pushed aside and the column could move. All the vehicles that were being towed as well as the four M41’s were left behind and later destroyed by Cobras.
Starting on 18 March, the NVA 324B Division had gradually closed around the LZ’s held by the Marines. On Fire Support Base Delta, the 147th Marine Brigade Headquarters received 400 incoming rounds that killed eight marines. The 7th Battalion maneuvering outside the LZ received about the same number of rounds and medevaced five wounded. An NVA defector from the 812th Regiment, 324B Division told the Marines that the entire 324B Division was committed to what the PAVN called the “Route 9 campaign” with its 29th, 803d and 812th regiments. The 29th Regiment had been beaten up pretty badly, but the 812th Regiment was intact and was engaging the 258th Marine Brigade at LZ Hotel. Positioned around Delta were about 10 antiaircraft guns entrenched on the mountain slopes around the base that could not be silenced. The 7th Marine Battalion operating outside the LZ was under constant pressure from fire and ground attacks. They reported that the enemy even used a noxious gas and tank mounted flame throwers.
On 19 March it was discovered that the 308th NVA Division with its 36th, 102d and 88th regiments was maneuvering to attack from the north. The 258th Brigade on Hotel was constantly under pressure and FSB Delta was encircled. The 2d and 4th Battalions were stopped when they tried to reinforce the base. Five of the ten 105-mm howitzers were out of action due to the enemy fire. NVA troops reached the defense perimeter and dug in making helicopter resupply impossible, but the 7th Marine Battalion and the troops of the 147th Brigade could hold on because they had a ten day reserve of supplies.
At LZ Delta a fierce attack began at dawn of 21 March by the 29th and 803d Regiments of the 324B Division supported by very accurate mortar and direct artillery fire said to be from tank guns. 175-mm guns provided close support as well as 13 tac air sorties and a B-52 mission that was diverted to the area. A prisoner of war later reported that a battalion lost 400 men from the B-52 strike. The NVA attack was stopped and the base held, but they had used up their reserve of supplies. A resupply effort was successful, seven U.S. UH-1H helicopters brought ammunition and took out wounded but an eighth helicopter was shot down. Two nights later LZ Delta was abandoned under cover of a B-52 strike. The Marines conducted an orderly withdrawal to Hotel that met no opposition.
For 24 March the 14th CAB daily log contains the entry, “LZ Hotel was evacuated without incident.” All South Vietnamese military units were now out of Laos, although for more then a week South Vietnamese soldiers, Marines and American helicopter crewmen would be showing up at U.S. firebases after walking out. So ended Lam Son 719.