Fire Support Coordination: Introduction

Page Title - Fire Support Coordination
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This publication presents a series of lessons learned on fire support coordination agencies, organizations, procedures, and techniques used by FWMAF, RVNAF, and US forces in the RVN. Specifically, it deals with artillery, armed helicopters, tactical air, and naval gunfire support operations. The basic purpose of this publication is to document FSC in the RVN for -

  • Units which request and receive fire support, to acquaint commanders with the support available and with procedures for getting that support.
  • Agencies which develop and disseminate doctrine and instructional material, for possible use to reinforce, review, or revise doctrine or training in FSC.


This Lessons Learned deals with the broad subject of FSC as it is carried out in the RVN. It addresses the factors which make FSC in the RVN different from and more complex than those experienced in wars in other areas and points out where modifications of doctrine and accepted procedures are necessary or desirable to meet the situation as it exists in the RVN. It assumes a general knowledge of FSC principles, procedures, and techniques, such as those presented at US combat arms service schools. Separate Lessons Learned are devoted to:

  1. Field artillery support. (ANNEX A)
  2. Armed helicopter support. (ANNEX B)
  3. Tactical air support, including reconnaissance. (ANNEX C)
  4. Naval gunfire support. (ANNEX D)
  5. Combined fire support coordination centers - an innovation in the RVN. (ANNEX E)
  6. An after-action report, Operation COBRA STRIKE, a joint combined operation which illustrates the successful integration of several fire support means. (ANNEX F)
  7. Glossary of Abbreviations. (ANNEX G)


a. Definition.

The US Joint Chiefs of Staff define FSC as "The planning and executing of fire so that targets are adequately covered by a suitable weapon or group of weapons". (JCS Pub 1)

b. Complexities.

(1) The definition itself needs no modification to apply to FSC in the RVN. However, several unique factors combine to make FSC in the RVN a complex and exacting procedure- more so than in previous wars. At the same time, fire support is more routinely available and in greater amount than in any previous war. In the great majority of cases, it is available in a matter of minutes - provided the ground commander knows of its availability and the procedures for securing it. The following factors tend to complicate FSC in the RVN:

  1. Parallel national command and communications channels (US, RVNAF, and FWMAF).
  2. Language difficulties.
  3. Populated and urban areas.
  4. Friendly and enemy intermixed.
  5. International, political, and tactical boundaries.
  6. Parallel national fire clearance procedures.
  7. Joint (multi-service) and combined (multi-nation) participation.
  8. Air warning requirements.

(2) These interacting factors, while resulting in a complex situation for the FSCOORD at any level, do not present an insurmountable problem. On the other hand, to appreciate the gravity of the situation, see MACV Lessons Learned No. 70, "Friendly Casualties from Friendly Fires", 17 October 1968.

c. Modifications.

The unique situation in the RVN has resulted in modification of terminology, doctrine, and procedures in FSC to meet the existing situation. These modifications are summarized immediately below and are dealt with in more detail in later parts of the paper.

(1) Terminology.

  1. The term "free fire area" is not recognized officially at the MACV level; "specified strike zone" is the approximate equivalent term.
  2. "Air strike" is used in its usual sense, except that B-52 strikes are excluded; therefore, strike aircraft are defined as fixed wing aircraft of the fighter, bomber, and attack classifications capable of conducting an air strike.
  3. Populated and urban areas are numerous and for most purposes constitute "no-fire areas".
  4. There is no bomb line(s) in the RVN; the entire republic is considered to be inside the bomb line.

(2) Divisional artillery differs in varying degrees from the textbook organization. For example -

  1. There is no Honest John battalion in any of the infantry divisions in the RVN.
  2. Mixed calibers of artillery function as a unit at some Fire Support Bases
  3. Some DS battalions have reorganized into two five-tube and two four-tube batteries.

(3) Field artillery support is widely available but the high degree of centralized control inherent in artillery doctrine is lacking, because the environment and nature of operations require wide dispersal of artillery.

(4) Deviations have been made from the fire support responsibilities inherent in the four standard field artillery tactical missions.

(5) The support of aerial artillery and other armed helicopters is much more extensive and available than might be the case elsewhere.

(6) TACAIR support is routinely available and in greater amounts than in any other war in history. Because of the relatively small area of the RVN and the presence of an extensive and elaborate TACS, TACAIR support is much more highly centralized than would be the case in a more conventional area of operations.

(7) TACAIR in the RVN has been tailored to operate in the relatively permissive environment that exists because of friendly domination of the air and lack of a really effective enemy air defense.

(8) A TACP is not normally found below brigade level in the RVN. In a more conventional situation, a TACP would be found with each maneuver battalion.

(9) The FAC is almost invariably airborne, as opposed to a more conventional situation where he would normally operate from a truck. This extensive use of the airborne FAC is dictated partly by the unfavorable terrain and environment and permitted because of friendly domination of the air and the enemy's limited air defense.

(10) Within its range, NGFS is routinely available for tactical operations along the entire coast of the RVN. In a more conventional environment, this support would probably be available for amphibious assaults only.

(11) The CFSCC has proved its value and its use is being constantly expanded.


a. Fire Superiority and Coordination.

  1. Friendly forces in the RVN have a great margin of fire superiority over the enemy. The means to destroy the enemy are readily available, which is confirmed by daily operational results expressed as KIA ratios; the daily RVN-wide enemy to friendly KIA ratio is routinely 6 or 8 to 1 and often 10 or 12 to 1. The problem with most tactical operations is finding and fixing the enemy. Once this is done, he can be destroyed with coordinated air strikes, artillery, naval gunfire (if available), and armed helicopters. The successful application of the fire support depends on close coordination.
  2. The keys to successful integration of the several types of fire support are effective radio communication and close personal contact.

    (a) The vital radio links are:

    • The artillery with the air and ground observers, artillery units, and armed helicopters.
    • The FAC and strike aircraft.

    (b) The essential close personal contacts are:

    • The infantry battalion commander and his artillery LO, his primary FSCOORD.
    • The FAC (and/or NGF spotters) and air observers.
    • Ground observers and maneuver elements.
    • Military commanders and local RVN government officials.

b. The Ground Commander's Role.

Most fire support planning and control in the RVN is at maneuver battalion level. The procedure which has evolved allows timely and effective engagement of targets by several fire support means with a minimum of danger to friendly troops and civilians. One such system is described below.

(1) FSC is usually exercised by the battalion commander through his artillery LO. Most operations are controlled from a command and control helicopter in which the commander and his artillery LO are located, all fire support (TACAIR, artillery, NGF, and armed helicopters) being controlled through the artillery LO. This procedure applied to artillery support is not unusual, but the method of coordinating TACAIR with other fire support will serve to illustrate the techniques which make the system so effective.

  • TACAIR is controlled through an airborne FAC, who is in UHF radio contact with the strike aircraft.
  • An artillery air observer is with the FAC; the air observer is in contact with the artillery LO, the ground FOs, the artillery battalion and battery FDCS, and the firing batteries on the artillery FM fire direction net.
  • This system allows the battalion commander, through his FSCOORD (the artillery LO) to control the artillery fires and the TACAIR support. A similar system with an air observer riding with the NGF spotter would extend the control to include NGF support.

(2) An example illustrates how near-simultaneous engagement of a target by several fire support means can be achieved by using this or a similar system. Assume a typical LZ preparation involving the use of artillery, TACAIR, and armed helicopters - the LZ being in a valley with high ground on both flanks. The sequence of actions during the LZ preparation might be as follows:

(a) Artillery fires are coordinated by the artillery LO and placed on the LZ under control of the air observer riding with the FAC.

(b) The artillery is shifted to block probable escape routes off the LZ and TACAIR is brought in under control of the FAC.

(c) When the strike aircraft have expended most of their ordnance, the FAC notifies the artillery LO through the air observer. The artillery LO alerts the armed helicopters which, as the strike aircraft make their last pass on the LZ, provide suppressive fires, then escort the troop carrier helicopters into the LZ.

(3) This second example illustrates the actual simultaneous engagement of the enemy by several fire support means. This action, which may well emerge as one of the classic examples of FSC in the RVN, took place in June 1969 at the 25th US Infantry Division's FSB Crook, northwest of Tay Ninh City near the Cambodian border.

(a) FSB Crook was circular, contained six US 105mm howitzers, and was defended by one reinforced US rifle company. Supporting artillery included 12 US and ARVN tubes of various calibers. TACAIR and helicopter gunships were available on call.

(b) Fire planning for the defense of FSB Crook was as follows:

  1. A circular band out to 700 meters from the perimeter was to be covered by direct artillery fire from within the perimeter.
  2. A north-south stream just west of FSB Crook was designated as a "safety line"; aerial fires were restricted to one side of this line and supporting artillery fires were restricted to the other side. This safety line concept is not contained in current FSC texts but had the effect of establishing a fire coordination line, two no-fire areas (one for artillery and one for aerial fires), and a restrictive fire plan for safety of friendly aircraft; in addition, it served as the basis for developing the artillery and air fire plans.

(c) The defense of FSB Crook, to include an early warning system, was planned six days in advance and the plan was executed as written.

(d) When the enemy attack came, the six 105mm howitzers within the FSB placed close-in direct fire around the perimeter.

  1. At the same time, supporting artillery fired preplanned concentrations in its sector in areas beyond the outer ring of these direct fires.
  2. All aerial fires were controlled by a USAF FAC on a specified frequency, clearing the FM voice command net for use by the ground commander. Aircraft were committed to assigned sectors as they arrived on station. Aircraft sectors were divided by visible terrain features to permit the simultaneous use of helicopter gunships and fixed wing aircraft. Continuous 7.62mm minigun coverage by AC-47 (Spooky) and AC-119 (Shadow) gunships was augmented by high-performance fighter delivery of heavy ordnance and napalm.

(e) The perimeter of FSB Crook was not penetrated. Planning and FSC had permitted the simultaneous use of artillery and aerial fires. Friendly losses were one killed and three wounded; 402 of the enemy died in their futile assault on FSB Crook.

c. Rules of Engagement.

For various reasons, e.g., populated and urban areas, intermingling of enemy and friendly civilians, international borders. and religious monuments and buildings, fire support in the RVN must conform to specific rules of engagement. These rules are jointly formulated and published by MACV in Directive 525-13 and the RVNAF JGS; they are applicable to the US, FWMAF, and RVNAF. The rules are not intended to restrict commanders unnecessarily in the performance of their missions, but they are necessary to limit the risk to the lives and property of friendly forces and civilians and to avoid the violation of operational and international boundaries. Subordinate headquarters are not allowed to modify or make substantive interpretations of the rules of engagement. These rules will not be discussed further here except to stress the extremely important mutual relationship between them and FSC.


Techniques which permit the simultaneous use of several fire support means in one target area have been proved in combat in the RVN. Effective FSC is basic to our military effort here. It has been the deciding factor in many engagements and has greatly contributed to our success thus far. With Vietnamization, its importance will not diminish. FSC has been aptly described as a "performing art" rather than a science, the fire support plan being the "single sheet of music" from which the FSCOORD orchestrates for the commander within his organization.


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Vietnam Lessons Learned No. 77: Fire Support Coordination in the Republic of Vietnam. United States Military Assistance Command, Vietnam, 20th May 1970



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