Department of the Army: Vietnam Studies.

Airmobility, 1961-1971.
Part 16, The "Cobra" Arrives

By LTG John J Tolson

Editor's Note: LTG Tolson's discusses the 1/50 (M) in the Battle of Tam Quan

On 1 September 1967, the first Huey Cobra (AH-1G) arrived in Vietnam. The initial six aircraft were assigned to their New Equipment Training Team, under the supervision of the 1st Aviation Brigade. Cobra New Equipment Training Team training started on 18 September with pilot transition courses and instruction on air frame, engine, armament and avionics maintenance. The Cobra was a major step forward in the development of the armed helicopter. For those pilots who had been flying the old, make-shift UH-1C's, it was a giant step.

After all this time there were many people, both in and out of the military, who didn't understand the role of the armed helicopter. Ever since Colonel Jay D. Vanderpool had tied a machine gun on a H-13 in the mid-50's, there were those who saw the armed helicopter as a fragile toy dreamed up by frustrated fighter pilots in the Army who were unable by regulation and budget to own really sophisticated attack aircraft. The consensus was generally that a semi-skilled skeet shooter or even a good slingshot artist could knock any helicopter out of the sky at short range and that an encounter with more sophisticated antiaircraft weapons would be suicidal. This attitude is quite understandable in duck hunters who never had the challenge of ducks shooting back. Also, the very nature of the helicopter, which looks very ugly and fragile compared to a sleek jet aircraft, adds to the conviction that flying one in combat is non-habit forming.

On the plus side, the helicopter is the most agile of all aircraft and has a capability of taking advantage of cover and concealment at extremely low altitudes that would be impossible in a fixed-wing airplane. It was soon proven that the helicopter was remarkably hard to shoot down and the most vulnerable part was the pilot himself. Personnel armor protection and armored seats greatly increased the pilot survivability. The experienced pilot used every unique aspect of the helicopter's flight envelope to his advantage.

Observation from the helicopter is unequaled. The enemy learned that to fire at one was to give up his advantage of cover and concealment and generally bring a devastating return of machine gun fire and rockets. A corollary to the advantage of seeing the enemy was the ability to identify our own troops with precision. Consequently, the armed helicopter pilot could safely place fires within a few meters of our own troops. This became particularly important as the enemy developed the "hugging" tactics which he used to avoid the heavier fires from our tactical air support and B-52 bombers.

The Army had long realized that the Huey-gun-rocket combination was a make-shift, albeit, quite ingenious, system that should be replaced by a new aircraft specifically designed for the armed mission. In the early 1960's, industry asserted that advance was within the state of the art. Experts in research and development urged the Army planners to go for a compound helicopter with an integrated armament system as soon as possible. They argued that it was technically feasible and procurement of any "interim" system would mean the Army would be stuck with an inferior capability for years to come. Moreover, it appeared that an advanced system could be procured almost as soon as an interim aircraft.

There were other pressures too. The Office of the Secretary of Defense had been critical of all the Services in their efforts to procure expensive weapon systems that appeared to offer only marginal improvements over the system they were to replace aircraft that flew a little higher or faster, tanks that had only slightly better performance, ships that cruised but a few knots faster. Ever since the Howze Board, the Army was sensitive to any criticism that it was striving for less than the best in airmobility. Also, the Air Force maintained that much of Army aviation duplicated an Air Force capability rather than, as the Army claimed, complemented Air Force support. The Army decided that its best option was to hold a design competition for a totally new system that would offer unique capabilities.

Unfortunately, what was a straight forward concept for a new armed helicopter soon became bogged down in a morass of permutations, modifications and additions to its design. The technicians had taken over from the tacticians. The concept grew in complexity and cost. Worse, it was being pushed into a later time frame when it was sorely needed in combat. Such things as a rigid rotor, ground avoidance radar, inertial navigation and computerization were straining the state of the art and pricing the Army out of mass production. A reevaluation was inevitable.

Bell Helicopter Company had prudently carried on its own research and development program using proven dynamic components of the Huey. Consequently, they were able to offer, at the appropriate moment, an "off-the-shelf" armed helicopter for just slightly more than the modified UH-1 that the Army was then buying to replace Vietnam attrition. The "Cobra" had enough speed to meet the escort mission; tandem seating; better armour; and a better weapons system. With the strong urging of the combat commanders, the Army decided to procure an interim" system for immediate requirements while it sorted out the problems of the "ultimate" system.


The history of the use, lack-of-use, and misuse of DECCA has many important lessons for future developers of airmobile equipment.

It was recognized by the earliest planners that one of the limitations of the airmobility concept would be operating at night and under periods of extreme low visibility. Research and Development offered many possible options to improve the helicopter's capability under these conditions, but all were expensive and complex.

The British had perfected a low-level radio navigational aid known as DECCA which essentially used three low frequency ground radio stations to propagate a series of hyperbolic curves which could be translated by a cockpit instrument into a position fix. Accuracy depended on the spread of the stations, the distance from the station, and the weather conditions. Because of the low frequency, one of the attractive features was its low altitude capability. This contrasted to the line-of-sight limitation of omnidirectional radio navigation aid and Tactical Air Navigation used by the Air Force. The Army tested several versions of the DECCA System and decided it had enough advantages to warrant its installation on command helicopters and lead aircraft.

A DECCA chain had been installed in Vietnam and in the early 1960's, the Army took over its supervision and maintenance. A big disadvantage in the DECCA system was the requirement for special maps printed with the hyperbolic grid and a reluctance by the user to take the time and effort to develop confidence in the system. Its use was further complicated by the resistance of the Air Force to accept a position report in instrument weather from a DECCA read-out as a positive fix. Many senior officers were dissatisfied with the accuracy and reliability of the DECCA system at night and eventually the DECCA died from lack of use and misuse. The requirement for a secure, accurate means of low-level navigation remained.

"Fire Brigades" Sent North

On 28 September the 1st Cavalry Division was notified that an increasing enemy buildup in the I Corps Tactical Zone might require that the III Marine Amphibious Force be reinforced. The 1st Cavalry was alerted to prepare one brigade. The brigade began movement on 1 October as the 2d Battalion, 12th Cavalry and the 3d Brigade command post departed for Chu Lai. By that evening the 3d Brigade command post, the 2d Battalion, 12th Cavalry, B Company of the 1st Squadron, 9th Cavalry and C Battery of the 1st Battalion, 77th Artillery were closed and the Brigade was under operational control of the Americal Division.

By 3 October all Brigade elements were in place and Operation WALLOWA began the next day with a series of air assaults. This deployment also involved the first major move of significant maintenance elements from An Khe to Chu Lai. This experience would prove to be extremely valuable in later operations in the I Corps Tactical Zone.

The concept of a brigade task force, in the U. S. Army's current division organization, is such that different battalions can be used under any brigade controlling headquarters. This allows a great deal of flexibility. For example, the 3d Brigade which had been deployed to the Dak To area and returned to the PERSHING area of operations had different battalions when it deployed to Chu Lai. During November we-were alerted to move another brigade back to the Kontum-Dak To area. This time I elected that the 1st Brigade headquarters under Colonel Rattan would control the task force.

The second battle of Dak To, under operational control of the 4th Division, has been extensively documented elsewhere. For the purpose of this study, it is important to note that the helicopters of the 4th Infantry Division, the 173d Airborne Brigade, the 52d Aviation Battalion, and the 1st Cavalry Division flew in excess of 10,000 hours in support of the battle. Over 22,000 sorties were flown, transporting 40,000 passengers and 6,000 tons of cargo. Dak To was another example of the flexibility of an airmobile division which allows its assets to be parcelled out as rapid reaction forces and still continues on a basic mission of its own. The large PERSHING area of operation was left with only one thin brigade during this period. I was glad we had spent so much time working with the 22d Army of the Republic of Vietnam Division on airmobile tactics, since the 22d, under the able leadership of Colonel Nguyen Van Hieu, would have to bear the major burden in Binh Dinh Province for a time.

Operation Pershing Continues

During the long period of the Binh Dinh operations, the 1st Cavalry Division had developed a special rapport with the regiments of the 22d Army of the Republic of Vietnam Infantry Division. The Army of the Republic of Vietnam regiments were assigned distinct areas of operation contiguous to the 1st Cavalry brigade areas and, teamed with 1st Cavalry helicopters, they became well versed in the intricacies of airmobile assaults. During Operation PERSHING over 209 joint operations were conducted with the 22d Army of the Republic of Vietnam Infantry Division. The 40th Regiment of this division played a major part in the Battle of Tam Quan.

Back in May 1967, the Division's capabilities had been greatly enhanced by the attachment of three companies from the 816th National Police Field Force. Introduction of the National Police Field Force into the PERSHING area of operations brought a new weapon to bear on the Viet Cong infrastructure. Now, the Division could conduct cordon and search operations of hamlets and villages with greatly increased effectiveness. The National Police Field Force squads were very important to 1st Cavalry operations in the Binh Dinh Province.

Tam Quan

The Battle of Tam Quan, 6 December to 20 December 1967, which was one of the largest battles during Operation PERSHING, was a good example of the "piling on" tactics which had been so successful in the early airmobile reactions to the enemy. The battle began with the fortuitous discovery of an enemy radio antenna by a scout team near the town of Tam Quart and a small force was inserted at 1630 hours on 6 December. Although the original enemy contact had been late in the day, the 1st Brigade reacted by "piling on" with a battalion of infantry and elements of the 1st Battalion, 50th Mechanized Infantry. On the following day, elements of the 40th Army of the Republic of Vietnam Regiment joined the fight and distinguished themselves by their aggressive manner. Throughout the battle, which was characterized by massive use of artillery, tactical air support, and air assaults by both the U.S. and Army of the Republic of Vietnam troops, the allied force held the initiative. There were frequent vicious hand-to-hand battles in the trenches and bunkers. The division used its mechanized forces to fix the enemy and drive him from his fortified positions. The airmobile units hit him when he tried to move. The enemy lost 650 men during this fierce engagement.

The Battle of Tam Quan had a much greater significance than we realized at the time. In that area, it pre-empted the enemy's Tet offensive even though the full impact wasn't then realized. As a result, that part of Binh Dinh Was the least effected of any part of South Vietnam during Tet.

1967 Draws to a Close

During the late fall of 1967, plans had been developed which would have a tremendous effect on the future of the 1st Cavalry operations during the next year. U. S. Army, Vietnam, Headquarters, for the first time in the war, had been given the mission of contingency planning. They began planning four contingencies which would project the 1st Cavalry Division into the I Corps Tactical Zone. I the Cavalry Would go north of Kontum and Pleiku . . . way north of Dak To; II the Cavalry would go up near Khe Sanh; III to Ashau; and IV the Cavalry would go into the big supply area west of Quang Ngai. The plans themselves, known as the YORK Series, are incidental but, like many contingency plans, they made the U. S. forces examine potential logistical bases, without which the plans were meaningless. The Marines were told to start working on Red Beach north of Da Nang as a logistical base to support the Cavalry in this series of operations. A smaller logistical base was to be set up at Hue-Phu Bai. Events were soon to prove that the logic behind this planning effort by U. S. Army, Vietnam, was indisputably sound.

The year 1967 had proved many important facets of the airmobile concept. Perhaps the most important facet that had been demonstrated without question was the inestimable value of the Air Cavalry squadron. This unit, especially in its operations in the I Corps Tactical Zone, had demonstrated its unique capabilities in uncovering the elusive Viet Cong. Practically every major engagement was started with a contact by the 1st Squadron, 9th Cavalry Troop, and the enemy was very slow in discovering means of coping with this reconnaissance in force.

The Air Cavalry squadron success in the airmobile division convinced higher headquarters that more Air Cavalry squadrons should be assigned to the theater to work with non-airmobile divisions. In my briefings to the many senior officers who visited the Cavalry Division, I never missed an opportunity to state that no matter what kind of a division I might be privileged to command in combat, I would fight tooth and nail for the capability of an Air Cavalry squadron.


Tolson, John J., Lt. Gen. Airmobility, 1961-1971, Part 16. Department of the Army: Vietnam Studies. Washington, D.C.: Government Printing Office, 1973.