Khe Sanh and PEGASUS

The base at Khe Sanh remained relatively quiet throughout the first week of the enemy Tet offensive, but the lull ended with a heavy ground attack on the morning of 5 February. The enemy penetrated the perimeter of the position on Hill 861A, and the resulting hand-to-hand combat drove the enemy back. A second attempt to overrun the position was less successful than the first. Elsewhere the North Vietnamese were more successful when, on 7 February, they struck at the Special Forces camp at Lang Vei.

The Lang Vei Special Forces Camp was located astride Route 9 some nine kilometers west of Khe Sanh Village. Beginning about 1800 on 6 February, the camp was subjected to an unusually intense mortar and artillery barrage. The defenders immediately responded with counter fire from the camp and requested supporting fire from the Khe Sanh Combat Base.

The enemy ground attack began about midnight on the morning of 7 February. The initial force to reach the protective wire around the perimeter included two of the approximately twelve Russian manufactured PT-76 amphibious tanks. The two armored vehicles were sighted in the outer wire on the southern side of the camp, taken under fire, and knocked out. (Map 10)

The armor defeating weapons in the camp consisted of two 106-mm. recoilless rifles, a few 57-mm. recoilless rifles, and 100 light antitank weapons known as LAWS. The LAW is designed to be fired once and discarded. These special weapons had been provided to the camp shortly before the attack as a result of intelligence reports which indicated that an attack was imminent and that armored vehicles would most likely be involved. Because of the newness of the weapons, few of the indigenous personnel and only half of the Americans had had the opportunity to fire the weapon before the attack. One survivor reported that several LAW'S failed to fire. This may have been due to lack of training or to improper storage.

Additional tanks moved around the destroyed vehicles and overran the company manning the southern sector. The friendly troops pulled back, but continued fighting. They fought the tanks with small arms, machine guns, hand grenades, and antitank weap-


Map 10: The Battle of Lang Vei Enemy Attack

MAP 10

ons. As the attack continued, the defenders were forced to continue their withdrawal from the forward positions. They re-formed in pockets and continued to resist and fire at the enemy troops and tanks as they moved through the camp. As the enemy soldiers advanced, they used explosive charges to demolish the fortifications within the camp. The enemy tanks used their 76-mm. main guns against the combat positions and tactical operations center in the camp.

As the battle continued, air strikes were called in. When day broke over the battlefield, the defenders located in the operations center called for and received air support to assist them in breaking out of the still surrounded position. Their escape was aided by a rescue force that had returned to the camp to help extract survivors. By day's end the camp had been evacuated and all surviving personnel extracted.

As the Lang Vei battle progressed, the Marines were requested to implement their contingency plan to reinforce the Special Forces camp. However, because of the fear that this attack was but a part of an all-out general attack in the area, Lang Vei was not reinforced. By noon on the 7th, General Westmoreland was being briefed on the need to evacuate the survivors. Also at the meeting were General Cushman and General Tompkins. General Westmoreland directed


that aircraft be made available to support the reaction force, and that afternoon the extraction took place.

When 7 February came to an end, the Lang Vei Camp was empty. Almost half of the 500 defenders were dead or missing. The survivors left behind them seven destroyed enemy tanks and at least as many enemy casualties as they themselves had suffered. The enemy attack stopped at the camp. It did not continue east toward Khe Sanh.

At Khe Sanh the marines were monitoring the battle at Lang Vei. After the seriously wounded had been evacuated by helicopter, the remaining survivors and many refugees moved east on foot. On the morning of 8 February some 3,000 refugees, including the Lang Vei survivors and Laotian 33d Battalion troops who had withdrawn from their attacked position on 23 January, appeared at the front gate of the Khe Sanh perimeter. At first denied admittance, the people were later searched and permitted to enter. Most were soon evacuated out of the area with the Laotians being returned to their own country.

At 0420, 8 February, a reinforced enemy battalion assaulted a platoon position of the 9th Marine Regiment. The marines were forced back from that portion of their perimeter which bore the brunt of the assault, but maintained control of most of the position. A company-sized counterattack at mid-morning restored the position, but the Marine commander at Khe Sanh decided to evacuate that platoon position because of its exposed location.

Enemy pressure on the Khe Sanh Combat Base continued during the following two weeks but not in the form of any major ground attacks. Probes, minor clashes, and sniping incidents occurred daily although the main enemy interest appeared to be the consolidation of his position and preparation for an all-out effort. In attempts to deter these preparations by artillery and air strikes, the marines were themselves hindered by the weather.

During this period Khe Sanh and its surrounding outposts continued to be supplied almost entirely by air. Marine and Air Force cargo aircraft made numerous daily runs to keep the base provisioned, to bring in replacement troops, and to take out wounded. The pilots had to brave both poor weather and intense enemy antiaircraft fire to accomplish these tasks.

On 10 February, a Marine C-130, loaded with fuel containers, was laced with bullets just before touching down on the runway. The aircraft was lost along with some of the passengers and crew. This incident caused major revisions in the offloading procedure. As a result of this loss and the damage inflicted on other aircraft


while on the ground, landings of the large C- 130 type aircraft were suspended at Khe Sanh on 23 February.

Operation NIAGARA II continued throughout this period. This intensive air interdiction campaign continued to provide excellent results. The high volume reconnaissance missions, added to other intelligence sources, recommended an average of at least 150 targets per day. On 15 February, one of the most lucrative targets, an ammunition storage area, was pinpointed 19 kilometers south southwest of Khe Sanh in the Co Roc Mountain region. Flight after flight of strike aircraft were directed into the area throughout a 24-hour period. Many secondary explosions and fires revealed additional stockpiles which were in turn attacked. In all, it proved to be a good day's work resulting in over 1,000 secondary explosions and fires, some of which continued two and one-half hours after a series of strikes had been completed.

Air operations on the logistical side also progressed. Following the termination of G- 130 aircraft landings, the Air Force introduced a new procedure to continue supplying the main Khe Sanh base. Known as the Low Altitude Parachute Extraction System or LAPES, this self-contained method of delivery had been put to good use while the air strip was being repaired in late 1967. The name of the system accurately described the technique. As the aircraft came in low over the airstrip, the pilot opened the tail gate and released a reefed cargo parachute which was connected to the pallet mounted cargo in the aircraft. When the pilot electrically cut the reefing line, it caused the parachute to fully deploy and inflate. The parachute then jerked the pallets out of the aircraft over the roller system mounted on the aircraft floor. After a five- to ten-foot drop, the cargo skidded to a halt on the runway. Experienced pilots could consistently leave their loads in a 25-meter square.

A second technique was also used to deliver cargo by aircraft without actually landing. This method, known as the Ground Proximity Extraction System or GPES, was used less frequently than the low altitude system. In the GPES delivery, as the C-130 aircraft came in low over the airstrip, the pilot would try to snag an arresting line on the ground similar to the line a navy pilot uses in landing on an aircraft carrier. The ground line then jerked the cargo from the opened rear of the aircraft.

About 65 deliveries using the low altitude and ground proximity systems were made before Khe Sanh was relieved and resupply effected by way of Route 9. By far, the majority of the supplies for the base were delivered by parachute because weather was too poor to permit the visual flying required for the two extraction type systems.


Another aspect of the air operations was the last leg of the resupply system in which helicopters picked up supplies at Dong Ha and carried them to the outposts on the surrounding hills. They faced the same problems as did the fixed-wing pilots, but to a greater degree. The low-flying helicopter pilots were more vulnerable than their higher flying, faster fellow aviators. Because of the additional exposure, helicopters soon were escorted by strike aircraft to provide suppressive fire as they dropped off supplies and picked up troops.

Helicopters were greatly affected by the weather. When the helicopters were grounded, life became hard on the marines in the outposts. One period of weather when the helicopters could not fly persisted for nine days and created such a water shortage that one small position was authorized to conduct a two-hour march to obtain water from the nearest stream. The patrol surprised a group of enemy soldiers and eliminated many of them.

Fighting on the ground in Operation SCOTLAND, a Marine designation, continued through the end of February. The last day of the month, 29 February, General Tompkins and Colonel Lownds pieced together the relevant facts to reason that a big enemy push was imminent. Each day brought better weather and longer flying hours. Numerous intelligence reports pointed to a massing of North Vietnamese units at three points around the main base. Although the enemy had failed to gain control of the hill outposts, he could not afford to let the weather improve much more before he acted.

During the early evening hours of 29 February, a string of sensors indicated a major movement of troops along Route 9. The fire support control center at the base directed all available assets against the area. The firepower was massive. Artillery, radar-guided fighter bombers, and minor and major B-52 strikes pounded the enemy's route of march.

A battalion of the 304th North Vietnamese Army Division made the first strike at 2130 on 29 February. The 37th Vietnamese Army Ranger Battalion received the brunt of the initial assault, and all available supporting fire was given the rangers. Hit with this concentrated firepower, the enemy was unable to breach the outer defenses. His second attempt two hours later met a similar fate. So did the third at 0315 on 1 March. The supporting fires had prevented the assault waves from gaining momentum.

Although the enemy continued to harass the base, to probe the weakness along the perimeter, and to shell it from a distance, he had changed his basic tactics. He assumed a less aggressive posture and began waiting for the Marine patrols to come to him. But this did not help him either. As time passed and the weather improved, in-


dications by mid-March were that major North Vietnamese Army units were leaving the area around Khe Sanh.

The Marine's last significant clash during Operation SCOTLAND took place on 30 March when a company, moving under a closely co-ordinated artillery support package, swept 850 meters south of the Khe Sanh perimeter and assaulted a heavily fortified enemy position. Surprise was with the attackers, however, and the marines drove the enemy out of his positions, destroyed the fortifications, and returned to their base.

Planning for Pegasus

The next day at 0800, SCOTLAND was officially ended. At that time, the operational control of the 26th Marine Regiment at Khe Sanh passed to the 1st Cavalry Division (Airmobile) which initiated Operation PEGASUS. The details of this operation are covered in Chapter V.

Elsewhere in northern I Corps Tactical Zone, it became apparent during late March that the enemy was continuing to build his base areas along Route 547 and had constructed an alternate route, 547A, from the A Shau Valley east towards Hue. These routes provided the enemy with a major artery for the movement of troops, supplies, and equipment out of the valley and into the denser jungle area between the valley and Hue. Reconnaissance of the area revealed a sophisticated communications system using wire lines and the presence of heavy automatic and antiaircraft weapons. Numerous caches of weapons, ammunition, and other equipment had been located by elements of the 101st Airborne Division operating along Route 547 and 547A west of Hue. These caches indicated the presence of 37-mm. antiaircraft cannons and tracked vehicles, probably tanks, in the area. General Westmoreland, after his 17 March visit to Provisional Corps, Vietnam, directed B-52 tactical airstrikes to interdict Route 547 and 547A.

Final preparations were being made for relieving the siege of Khe Sanh by the reinforced 1st Cavalry Division. On 22 March General Rosson held a meeting with division commanders at Camp Evans, 15 kilometers southeast of Quang Tri City and formulated plans for the relief of 1st Cavalry Division elements from their area of operation along the coastal areas of Quang Tri Province by units of the 101st Airborne Division. To insure that a sufficient force would be available to offset a new enemy threat at Hue, General Rosson requested that the Vietnamese Marine Task Force be retained at Hue. If the force could not be retained, he requested that a fourth Vietnamese Airborne Battalion and U.S. forces be made


available for employment in the Hue area. General Cushman forwarded General Rosson's report to General Westmoreland with a recommendation that the airborne task force be raised to four battalions for the Con Thien-Gio Linh operation. The Con Thien operation was envisioned as a deception plan for Operation PEGASUS. This operation would also place the airborne task force closer to the ultimate zone of action in the Khe Sanh Operation.

General Rosson, Captain Smith, the commanding officer of Task Force CLEARWATER and the Commander of the Naval Support Activity in Da Nang met at the III Marine Amphibious Force headquarters with General Cushman to discuss the deception plan and to determine the details of its implementation and its effect on logistical support in northern I Corps Tactical Zone.

Operation Orders

The Third Marine Division issued its operation order on 25 March to cover both the Con Thien-Gio Linh operation, which would be executed in conjunction with U.S. Army elements and the 1st Vietnamese Division, and Operation PEGASUS. The 4th Marine Regiment was to secure Route 9 and provide convoy security in its area. The 9th Marine Regiment was to provide security for Route 9 in its sector. The 12th Marine Regiment was instructed to support the attack of the 1st Cavalry Division within its artillery capabilities.

As the enemy activity around Khe Sanh tapered off, it appeared that Operation PEGASUS might go much quicker than originally anticipated. If true, this would relieve elements of the 1st Cavalry Division for earlier commitment to attacks in the A Shau Valley area. General Westmoreland expressed the view that Operation PEGASUS was to exact the maximum destruction of enemy forces and facilities, and its duration would therefore have to depend on the tactical situation as it developed. General Cushman and General Rosson assured General Westmoreland that all preparations for Operation PEGASUS would be ready for the planned 1 April attack. General Westmoreland also approved the concept for a later operation in the A Shau Valley presented by the III Marine Amphibious Force. Thus, the logistical planning for the operation into the A Shau Valley was conducted concurrently with logistical support for PEGASUS and it was envisioned that the second operation would continue as a smooth transition from the first.

Provisional Corps, Vietnam, Operation Plan 1-68 was redesignated Operation Order 1-68 with D-day, H-hour, established as 01001 April. General Tompkins, Commanding General, 3d Marine Division, ordered the execution of a deception operation with D-day,


H-hour, established as 0600 on 30 March. The U.S. elements participating in the combined operation were designated Task Force KILO and the Vietnamese Army portion of the operation designated LAM SON 203. The deception operation envisioned a task force attacking northeast from Dong Ha toward the demilitarized zone.

As the final co-ordination was being accomplished to insure all units were ready for the pending operation, some elements were already at work. In addition to the U.S. Air Force actions in preparation for the operation, the 1st Squadron, 9th Cavalry of the 1st Cavalry Division, was directing strikes to eliminate antiaircraft positions in the area before the airmobile division committed the bulk of its helicopters. Heavy U.S. Air Force strikes had stripped away much of the concealment needed by the enemy. With the addition of the reconnaissance squadron of the 1st Cavalry Division, the effectiveness of artillery and air strikes directed against the enemy antiaircraft positions was almost total. As the final hours of March ticked away, the Free World Forces awaited the signal to strike.

page created 15 January 2002

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