Document created: 8 July 04
Air University Review, March-April 1970

Close Air Support

Major William A. Gorton

A conversation between two forward air controllers (FAC’S) recently returned from combat tours with Army units in South Vietnam might sound something like this:

 First FAC: Joe, which bird did you find best for close air support?

Second FAC: No question in my mind on that one, Sam—the good old A-1. Man, could those guys put’ em in there with that bird! Just where I wanted’em—every time!

First FAC: Yeah, they were good all right, but in my area their response time was pretty long. Besides, those F-4s really carried the goodies. When I needed the heavy stuff, and lots of it, I sure liked to see those F-4s coming!

Second FAC: The A-1s did take some time getting to me, but I normally preplanned a couple “on station,” and that way I had ’em right over the battlefield just waiting for Charlie to show.

The conversation is just getting started, and they will soon be talking about the relative merits of B-57s, F-l00s, A-37s, AC-47s, all types of air munitions, and equipment not yet on the drawing boards. Should an Army troop join the conversation, it could go well into the night.

It should not be surprising that there are differences of opinion regarding which aircraft or combinations of aircraft are best for providing close air support to ground troops. The arguments generally center on whether it is best to employ a specialized aircraft designed solely for close air support or a multipurpose aircraft with greater utility over the full spectrum of tactical fighter missions.

However, a case can be made for a close air support concept that employs a tactical fighter force comprising a limited number of specialized close air support aircraft and a greater number of multipurpose tactical fighters. This concept of dose air support employment will be discussed in the context of the air and ground war in South Vietnam. That environment has been selected for two reasons. First, it is generally conceded that a “permissive air environment” has existed in South Vietnam; that is an environment in which we have had air supremacy and the enemy anti-aircraft threat is of a low order—primarily small arms and automatic weapons.¹ Because of the characteristics of a specialized close air support aircraft, a “permissive air environment” is desirable in order to utilize the aircraft fully in the role for which it was designed. The second reason for selecting the South Vietnam environment is that my own combat experience, as an Air Liaison Officer (ALO) with an independent Army brigade, is limited to that area.

Before considering how tactical fighters might be employed to enhance our ability to provide timely and effective close air support, let us review some typical target situations and the requirements generated by those targets.

targets and target requirements

The character of the ground war in South Vietnam is diverse. A friendly ground force engaged in an operation may make contact with a well-equipped North Vietnamese Army (NVA) unit, and the ensuing battle may last for days. On the other hand, that same ground force on the same operation may be confronted by a small guerrilla unit, and the engagement may last only minutes. Because of this diversity, the close air support forces supporting the ground operation must be able to provide not only rapid response but sustained response as well. Yet often when a ground element begins to receive enemy fire, considerable time elapses before the size and type of enemy force can be determined. What was thought at first to be a small Viet Cong force may turn out to be an NVA or VC main force unit that is dug in and ready to fight. In both instances there may be a call for rapid close air support to silence the initial enemy firing position; in the latter, however, there will also be a need for follow-on and sustained close air support.

Because small guerrilla units are well trained in the tactics of dispersal when confronted by a superior force, such a target is normally short lived and must be struck immediately. Another consideration is that only the target should be struck. Often a hamlet guerrilla unit will fire from a position in or near a populated area. It is then important that our firepower be “surgically” applied, thereby limiting destruction of nearby life and property to an absolute minimum.

Today, in Vietnam, the war is still primarily characterized by small-unit operations, brief encounters of South Vietnamese or allied units with the VC. Although these engagements make few headlines, the necessity of destroying the guerrillas’ ability to terrorize and control the populace is still a paramount consideration. How can tactical air power be effectively and efficiently employed to aid friendly ground units in dealing with both the local VC and the NVA?

force employment

In order to meet the diverse close air support requirements generated in South Vietnam, our force employment concept must be flexible. We must be able to concentrate our tactical fighter forces rapidly in support of a major ground engagement while, at the same time, providing rapid response against fleeting targets. But these two requirements, rapid response and concentration of force, create a dilemma.

The best way to provide rapid response is to place tactical fighters “on station” over the ground operation, thereby reducing response time to the few minutes required to attack a fleeting target. However, to position our force in that manner would require many sorties to cover a single ground operation. For example, let us assume that we employ multi-purpose F-4 aircraft, in flights of three, each flight “on station” for one hour, for a twelve-hour period.² This would require 36 F-4 sorties to be flown in support of a single ground operation. Should no enemy contact be made, it would mean that 36 bomb loads would be dropped on secondary targets. Thus the number of sorties flown would be considerable when viewed from a theater-wide perspective. The cost of bombs, fuel, and manpower required to sustain such air operations would be high. The total number of tactical fighter aircraft needed to do the job would be larger than we now have or can expect to have in the future. It becomes obvious, when considering all the ground operations which may be taking place at one time, that the “on station” tactic is an inefficient way to employ multipurpose fighters on a day-today basis. Furthermore, we lose flexibility, since a large portion of the fighter fleet would be airborne or tasked to support a specific ground unit, which could well cause delays in our ability to concentrate our force rapidly against a lucrative target.

Conversely, the best way to provide for rapid concentration of force in response to a major ground engagement is to keep our fighters in a ground alert status, fully loaded and ready to take off as soon as it is confirmed that a major engagement is under way. But this tactic is not acceptable for two reasons. First, rapid response to fleeting targets would be precluded. And second, the determination of what is or is not a major ground engagement is rarely clear at the outset of a ground action. This problem might bring about disastrous delays in providing air support.

It appears therefore that, if we are to meet the requirements of rapid response and concentration of force effectively and efficiently, the proper tactical fighter force employment concept must be a compromise between “on station” and ground alert that will provide the needed flexibility.

the “cork-puller concept”

The concept of a close air support force described here as “cork-puller” consists primarily of the F-4 and A-7 aircraft, plus a new aircraft created for the purpose of illustrating the concept. We will call this new specialized close air support aircraft the A-10. In addition, O-2 and OV-10 FAC aircraft will be employed as they are presently used in South Vietnam. The employment of the USAF Tactical Air Control System (TACS) will also remain the same. Some aircraft presently in use in South Vietnam, such as the F-100 and 8-57, are not considered because it is assumed that they will not be part of the tactical inventory during the time period when the concept could be employed. The performance characteristics of the F-4, OV-10, and O-2, being well known already, will not be discussed; however, the A-7 and A-10 require some explanation.

The A-7 will soon enter the tactical fighter inventory. It is a subsonic, ground attack aircraft that can deliver a wide variety of munitions in adverse weather, both day and night. One of its outstanding characteristics is the ability to stay “on station” for extended periods of time. A drawback is that it must be operated from a main operating base (MOB) because of its need for lengthy, prepared runways for takeoff and landing and considerable maintenance support facilities.

The A-10, as a new addition to the tactical fighter forces, would have the following characteristics:

Simplicity. The aircraft will be easily maintained at austere forward operating bases (FOB’S) and capable of high utilization rates. It will normally require only fuel, oil, and munitions between flights. It will be capable of operating on a sustained basis from an FOB with a 2000-foot semiprepared runway and minimum maintenance facilities.

Maneuverability and speed. The A-10 will have a low wing loading which will enable it to deliver air munitions under low ceilings and rapidly maneuver for target reattack. High-speed flight will not be a characteristic of the A-10, having been traded off in favor of low-speed munitions delivery.

Armor protection. The A-10 will be heavily armored. It will have critical component armor protection against smallarms and automatic weapons through 14.5-mm. Its power plant will be heat-shielded to provide a low infrared signature.

Munitions. The A-10 will use munitions tailored for the close air support role. These munitions will consist primarily of small, 100-to 250-pound bombs, napalm bombs, and cluster bomb unit (CBU) canisters. In addition, the A-10 will have four low-rate-of-fire, high-velocity 30-mm cannons. The pilot will be able to elect to fire all guns at once or separate pairs of guns.

Endurance. The A-10 will remain “on station” at 5000-feet altitude or below for a minimum of 5 hours, with reserve fuel for landing.

Avionics. The A-10 has no avionics per se. Only basic flight instruments and navigational aids, such as TACAN are installed.

Fire control. The A-10 will have a simple ground attack sight. Possibly a fixed reticle sight will be all that is required.

Radios. In addition to the normal UHF radio, the A-10 will also have an FM radio for direct contact with ground troops and a VHF radio for FAC communications.

In short, the A-10 is a simple, rugged, and relatively inexpensive aircraft wholly specialized to provide “on station” close air support. As will soon be seen, it is the “cork-puller” in the “cork-puller concept.”

As major components, the concept calls for A-10 aircraft staged from FOB’S and flying preplanned “on station” missions, backed up by A-7 and F-4 aircraft at MOB’S on ground alert status, ready to handle any immediate and certain preplanned requests for close air support.³

The A-10 will be employed in flights of two aircraft on four-hour “on station” missions. Each aircraft will be armed with a large number of small bombs, possibly as many as 36 in number, plus a full load of 30-mm ammunition. A flight will be tasked to support a particular ground operation and will be controlled by an airborne FAC. The decision as to whether A-l0s will be requested to support a particular ground operation will be made by the appropriate ground unit commander with the advice of his ALO. Normally, an A-10 mission will be requested only when current intelligence indicates that enemy contact is likely or when the importance of the operation is such that rapid response is mandatory. Theater A-10 forces will be apportioned and allocated by the joint task force commander or unified commander and his component commanders, respectively.

The ground alert forces, the A-7s and F-4s, will be scheduled to stand 5-, 15-, and 30-minute alert. The A-7s will meet the 5-minute alert requirement and as much of the 15-minute alert as the size of the force allows. The F-4s will cover the remaining ground alert requirements. All aircraft standing alert will have mixed munitions loads. The remaining theater fighter forces that have been allocated for close air support will be tasked to perform preplanned missions, such as landing zone prestrikes. The proportion of the F-4 and A-7 fleets that are scheduled for ground alert and preplanned missions will be determined on a daily basis dependent upon the ground and air tactical situations.

How might this concept work in response to an actual operation? First, let’s assume that three A-10 missions have been preplanned to provide “on station” coverage of a particular ground operation. The operation is a brigade-size search and destroy mission which is attempting to locate and engage a VC main force unit reported in the area. At 0600 hours, two A-l0s check in with the airborne FAC, “on station” over the ground operation. For the first four hours, the friendly ground forces make no contact with the enemy, and the first A-10 flight is directed by the FAC to a preselected secondary target. The fighters quickly release their bombs and return to the FOB to refuel and rearm.

The second A-10 flight checks in with the FAC at 1000 hours for the next four-hour mission. Soon after the second A-10 flight’s arrival, a ground element makes contact with an enemy force of unknown size. The ground element commander calls the FAC and requests an air strike. At the moment the air strike is requested, the FAC, through his ALO, requests that a ground alert flight be scrambled. It is important to note that the ground unit did not specifically request that the ground alert mission be scrambled, although there was a request for fighters “on station” for the operation. The reason for this Air Force-initiated request is twofold. First, the A-10 flight is soon to be expended on a target, and the next A-10 flight is not scheduled to be available until 1400 hours. Something is needed to fill the gap that will be created in the “on station” coverage schedule. And second, the size and type of the target are still unknown. It might be the VC main force unit or only hamlet guerrillas. If it is the former, then massive close air support may be needed, and getting the ground alert aircraft on the way to the target early could pay great dividends.

Using 30 minutes as an average response time from a five-minute ground alert posture, the FAC keeps the A-10 flight on-target until the A-7 flight arrives. This is accomplished by expending only a few bombs on each pass at the target so as to keep constant firepower on the target for the 30-minute period. During the period that the A-10 flight is on-target, more information is gained on the nature of the target. This information is provided by the ground element commander, the FAC, and the A-10 pilots. Frequently the FAC is better able than the ground commander to determine what kind of target is being engaged. From his elevated view of the battlefield, he can spot enemy troop movements or positions that may be obscured from ground observation. Also, the type and quantity of ground fire directed against him and the fighters provide a good indication of the size and type of the enemy unit. In any event, a decision must be made during the first 30 minutes of target engagement as to whether a second A-7 strike will be needed. If the unit commander requests it, another A-7 flight will be scrambled. The first A-7 flight will then be directed on the target, while the second A-7 flight will provide the gap filler in the “on station” schedule. Once again, the FAC should request the second flight of A-7s if, based on his experience and knowledge of the situation, the target is lucrative. He thus once again anticipates ground request for air firepower.

This chain of decision and request will continue until the target is effectively neutralized. If the target is the beginning of a major ground engagement, fighter forces can be employed in a continuing series, thereby providing the necessary concentration of force. If the target is a small VC unit and quickly neutralized, then we can easily revert to an “on station” posture. In this concept of employment, the A-10 represents the “cork” in the fighter force “tub.” When the FAC employs the A-10 flight against a “hot” target, he effectively pulls the cork which triggers a flow of fighter aircraft to the target area.

advantages of the cork-puller concept

While the greatest advantage of the cork-puller concept is that it provides for both rapid response to fleeting targets and concentration of force in major engagements, there are some additional advantages as well. One such advantage deals with the cost of employing the fighter forces.

In a war characterized by small-unit engagements, the lion’s share of the close air support requirements would be met by the A-10 force. Because of the A-10 characteristics of simplicity and maintainability, the cost of operating such a force would be considerably less than the A-7/F-4 force in the same role. In the target engagement example, only three A-10 missions of two aircraft each were necessary, whether or not a target was engaged. This is a 1.5 sortie rate per four A-10 aircraft assigned, an easy rate to maintain on a sustained basis for as simple an aircraft as the A-10. Furthermore, only a maximum of three secondary targets were struck, thereby reducing munitions expended.

Cost savings will also accrue through the use of small air munitions on the A-10. Because of the small size of the munitions, they will require little or no special equipment for up-loading on the aircraft; in fact, many could be man-handled.

Another cost advantage is realized in A-7/ F-4 ground alert flights not scrambled. Since these flights are primarily employed in support of engaged troops, their use is in direct relationship to the number of “hot” targets generated. The A-7/ F-4 force application against secondary targets is held to a minimum, since the only time they will be required to strike a secondary target is when they are performing a gap-filling mission in the “on station” schedule. The cork-puller concept therefore provides for the most effective and productive use of the costlier A-7/F-4 force.

Another advantage of this concept is that the A-10 is an ideal aircraft for use by USAF Special Operations Forces (SOF) in counter-guerrilla operations—in fact, in its design, consideration should be given to SOF requirements. In this regard, it should be readily exportable through the Military Assistance Program to developing nations to aid in their efforts against subversive insurgency.

impact on fighter force structure

In adopting the cork-puller concept, one must consider its impact on the capability of the total fighter force to conduct effective operations at higher levels of conflict. Because the A-10 requires a permissive air environment, its utility in the close air support role will decrease as the air environment becomes less permissive. Since we must be prepared to conduct effective tactical air operations at all levels of conflict, it is apparent that we cannot afford many A-10s in the tactical fighter force structure. For, with large numbers of A-l0s in the force, the overall capability of the total force to effectively conduct other tactical air operations would be reduced. (This assumes that the A-10 will be purchased in lieu of multipurpose fighters.) Yet, proper execution of the cork-puller concept will not require large numbers of A-10 aircraft. In view of the numerous cost advantages which will accrue in application of the concept, it is possible that the required A-10 force could be added to the fighter force without a significant increase in cost of total force operations.

Another consideration in regard to this concept is the lower utilization rates of the A-7/ F-4 forces. Under the concept, A-7/F-4 forces will operate primarily from a ground alert posture in response to “hot” targets, and it is quite possible that low sortie rates could result. This might cause pressures to build for an overall fighter force reduction on the basis that we have more multipurpose tactical fighters than we can efficiently utilize. But, in my opinion, efficient and effective fighter force utilization is not measured by the number of sorties flown or the number of bombs dropped; it is measured only by the number of enemy killed and supplies destroyed.

The cork-puller concept represents my ideas on how a specialized close air support aircraft could be combined with our multipurpose fighters to enhance our ability to provide responsive and massive air firepower. I am in hopes that the concept will, at the very least, stimulate further thinking about the subject of close air support and how the Air Force can continue to improve its capability in this important role.

Hq United States Air Force

Notes

1. There have been times, as at Khe Sanh and A Shau, when the enemy has mounted a significant antiaircraft threat. However, these instances are exceptions to the general state of the environment.

2. The three-aircraft flight composition is typical for F-4 and F-100 operations in South Vietnam.

3. This is not to say that the A-10 would not operate from an MOB or, for that matter, from a field more austere than an FOB; e.g., a road segment. The area and location of potential and actual ground operations would be a primary consideration in positioning theater A-10 forces. 

Contributor

Major William A. Gorton (M.B.A., Auburn University) is an Operations Staff Officer, Europe/NATO Branch, Plans Directorate, Hq USAF. After flying training, 1955, he served in TAC and USAFE flying F-104, F-100, F-86, and F-84 aircraft. Subsequent assignments have been with the 101st Airborne Division as a Forward Air Controller and Air Liaison Officer; and with the Fighter Commitments Branch, Directorate of Fighter Operations, Hq TAC. Major Gorton is a graduate of Squadron Officer School and Air Command and Staff College.