Air University Review, September-October 1985
Lieutenant General Merrill A. McPeak
WE are at the threshold of a period of greatly increased joint effectiveness on the tactical battlefield. The work done principally by TAC and TRADOC1 during the past several years has been crowned, in a sense, by the thirty-one initiatives of the two service chiefs.2 As we begin to think about how to exploit the opportunities now presented for enhanced joint effectiveness, it may be useful to review the classic air-to-ground missions––air interdiction and close air support––in the context of their associated coordination mechanisms and control measures. While much remains the same, some very important recent changes have occurred, including, in my view, adjustments in our basic conceptual approach.
As an example of how our thinking has shifted, as recently as 1978, an experienced tactician, writing in this publication, could assert:
The dividing line between close air support and interdiction has always been the fire support coordination line (FSCL)....
... Pact forces or "echelons" beyond the FSCL can be freely interdicted without the need for constant air-ground coordination. The Pact forces or "echelons" between the FSCL and the forward edge of the battle area (FEBA) can only be attacked within the framework of the close air support system and whatever coordination procedures and rules of engagement are operative within the system at that time. Separating close air support and interdiction operations on the battlefield is relatively simple.3
In my opinion, almost nothing in these quoted paragraphs is correct today. To understand why, we have to go back to basics.
Ground forces use a variety of control measures, most of limited interest to the tactical aircrew involved in air-to-ground operations. For our purposes, only the FLOT, FEBA, and FSCL need elaboration.
The FLOT and FEBA are battlefield-planning lines that describe the present position of friendly forces. The Dictionary of Military and Associated Terms (JCS Pub. 1) definitions are:
(FLOT)––A line that indicates the most forward positions of friendly forces in any kind of military operation at a specific time.forward line of own troops
forward edge of the battle area
(FEBA)––The foremost limits of a series of areas in which ground combats units are deployed, excluding the areas in which the covering or screening forces are operating, designated to coordinate fire support, the positioning of forces, or the maneuver of units.Each ground maneuver unit establishes FLOT and FEBA lines to determine unit deployment. The FLOT encompasses all of the unit's people. Accordingly, the FLOT is likely to extend well beyond the location of the main body of friendly troops to incorporate screening or covering forces. On the other hand, the FEBA depicts the forward limits of the main battle area and specifically excludes the screening or covering force.
In today's doctrinal dialogue, one does not hear much discussion of the FEBA. Interest has shifted to the FLOT. In a 10 August 1981 memorandum to his commanding general, then Brigadier General McDonald Morelli of TRADOC described the Army's rationale for emphasizing the FLOT:
The primary reason the US adopted FLO AirLand Battle operational concepts stemmed from the change in the operational concept and mission of the Corps Covering Force, approved by General Starry several years ago. Essentially, when General Starry decided that the Covering Force would be the first echelon of defense and fight a major battle to force the enemy to deploy his main body, there was no way to depict a FEBA for this "battle area" and remain in consonance with approved NATO terms (NATO definition of FEBA excludes the covering force operations). General Starry decided to use FLOT since the Covering Force Battle was to be the baseline where he wanted the time lines established and the AirLand Battle to begin.4
In brief, today's baseline battlefield control measure is the FLOT.
According to JCS Pub. 1, the planning line most often linked with tactical air operations is the FSCL, defined as:
(FSCL)-A line established by the appropriate ground commander to insure coordination of fire that is not under his control but may affect current tactical operations. The fire support coordination line is used to coordinate fires of air, ground or sea weapon systems using any type of ammunition against surface targets. The fire support coordination line should follow well-defined terrain features. The establishment of the fire support coordination line must be coordinated with the appropriate tactical air commander and other supporting elements. Supporting elements may attack targets forward of the fire support coordination line without prior coordination with the ground force commander, provided the attack will not produce adverse surface effects on, or to the rear of, the line. Attacks against surface targets behind this line must be coordinated with the appropriate ground force commander.5fire support coordination line
The FSCL is based on and measured from the FLOT. Ideally, the FSCL should be placed as close to the FLOT as operational and safety considerations permit––say, about ten to fifteen kilometers. For reasons that we shall elaborate later, the FSCL is nearly always found at least twenty-five kilometers from the FLOT when operating with U.S. ground forces.
Historically, the FSCL is the lineal descendant––no pun intended––of the "no bomb line." Before the advent of accurate navigation aids and the current air-ground operations system, easily recognizable terrain features were used to separate the Army and Air Force portions of the battlefield. As one young Army author noted: "Given the problems of communications, coordination, and response time, rigid separation of Army and Air Force fires was the only way to attack targets while protecting our own troops."6 We should not minimize these difficulties even today, but our focus now is on how to attack the target set jointly, rather than on a battlefield that is hived off into exclusive domains.
While the requirement to coordinate attacks inside the FSCL is clear, there is no JCS Pub. 1 definition of "coordinate." By way of general guidance, JCS Pub. 2, Unified Action Armed Forces, describes the coordination process:
The commander of the supported force [will] indicate in detail to the supporting commander the support missions he wishes to have fulfilled and provide such information as is necessary for complete coordination of the supporting action with the action of his own force.
In other words, coordination during attack planning seems not to require active involvement of the supporting force when that force is responding to the request of a supported force. Whatever "coordination" is, responsibility for doing it rests mainly with the commander seeking the action. In the case of fire support, the request specifies desired target and time over target. As a consequence, one could argue that the request itself embodies the requesting commander's coordination.7
To summarize, we are required to "coordinate" attacks inside the FSCL. The particulars of coordination are not well defined. And in the case of attacks requested by the ground commander, the request itself may be viewed as incorporating the required coordination.
JCS Pub. 1 defines our principal air-to-ground missions as follows:
––Air action against hostile targets that are in close proximity to friendly forces and that require detailed integration of each air mission with the fire and movement of those forces.close air support
air interdiction
––Air operations conducted to destroy, neutralize, or delay the enemy's military potential before it can be brought to bear effectively against friendly forces, at such distance from friendly forces that detailed integration of each air mission with the fire and movement of friendly forces is not required.Note the absence of any reference to the FSCL. No form of the verb "to coordinate" is mentioned in either definition. As can be seen, what distinguishes close air support from air interdiction is the element of "close proximity"' together with its associated requirement for "detailed integration"––not the question of where the mission is conducted relative to the FSCL, with its associated requirement for "coordination."8 (Those who claim that we do only CAS inside the FSCL should advocate changing its name to fire support detailed integration line.)
As with "coordination," there is no agreed military definition of "detailed integration." In practice, "detailed integration" refers to a comprehensive planning and execution process that extends from target and munitions selection through weapons delivery and incorporates "coordination" as a part of the process. In essence, the ground commander chooses CAS targets, desired munitions effects, and attack timing. A tactical air control party (TACP)––notably the corps air support operations center (ASOC)––does detailed planning to integrate requested attacks with the ground maneuver scheme. Forward air controllers (FACS) communicate with air and ground mission commanders, providing terminal control while weapons delivery is performed.
Adding a final complexity to this vexing question of definitions, "close proximity" has no jointly agreed meaning. From an airman's viewpoint, when the position of friendly troops is known precisely, safety considerations argue for a nominal safe distance to account for delivery system accuracy and frag envelope––say, one to five kilometers. For the Army, "close proximity" is usually associated with the limits of observed fire. The distance at which ground fire can be observed will vary with circumstances, but a good working number is three to five kilometers. Thus, by most accountings, close proximity" ends at some point well inside the FSCL.
The lack of precision in agreed definitions, especially that of "close proximity," increases the potential for confusion. The situation is certainly clarified if we take the view that, inside the FSCL, we do close air support exclusively and, outside the FSCL, we do air interdiction exclusively. Were this the case, the FSCL would constitute a mission line, rather than simply a coordination line. Indeed, such an arrangement would work well if the FSCL were to be placed in such a way that it could be used as a reasonable guide for "close proximity." However, this is very unlikely to happen, for a variety of reasons:
Thus, we almost never see FSCL placement inside twenty-five kilometers from the FLOT. Thirty to forty kilometers seems to be the U.S. norm, and the distance can be even greater under certain battlefield conditions.
Accordingly, we cannot expect the FSCL to constitute a reasonable boundary line between close air support and air interdiction. As a consequence, were we to insist on not doing air interdiction inside the FSCL, it would be possible to construct a doctrinal "no-mission zone." In the area between about five kilometers from the FLOT out to the FSCL, we would not do close air support, because targets are not in "close proximity" to friendly forces, and we would not do AI, because the targets are inside the FSCL. There is "no mission" that applies in the zone where attacks must be coordinated but need not be integrated.
A major disadvantage of the FSCL as a battlefield control measure is that it bears no direct relationship to the density or distribution of enemy targets. It was never meant to, being primarily a safety measure, but one could argue that the shortcoming was less important in previous times because the target array was rather different. Formerly, we thought of ground forces as being concentrated more narrowly at the front, with only a relatively small reserve held out of the fight. Away from the point of contact, there was a rapid diminution in targets that could have a near-term impact on the battle.
Our present view is of a battlefield of great depth, featuring the arrangement of enemy forces in a succession of echelons. For example, the standard depiction of Soviet-style echelonment shows the first-echelon division in the area from zero to thirty kilometers from the FLOT. (See Figure 1.) This places it inside the nominal FSCL. The first-echelon division includes two sets of targets: (1) first-echelon regiments, in the zone from zero to fifteen kilometers, deployed for combat, and either in contact or "close proximity." Obviously, this is the CAS target set; and (2) second-echelon regiments, in the zone from fifteen to thirty kilometers, in tactical march column, moving to contact, but not yet in "close proximity" as usually defined. This is the leading edge of a series of formations we lump together under the heading "second echelon," the elements of which extend rearward to considerable depth. We are likely to see at least the second-echelon regiments of the lead division inside the FSCL. Fire support coordination line placement beyond thirty kilometers (which we can expect) would also incorporate some elements of the second echelon division.
Clearly, we must attack the second-echelon target set. We could even argue that, in some respects, it is an easier target than enemy forces in contact. Second-echelon vehicles will likely be lined upon roads instead of dispersed, under cover, mixed in with our own, etc., and at least some organic air defenses will be buttoned up for travel. It is of special importance that we attack second-echelon targets inside the FSCL, since these targets constitute a more or less immediate problem for the ground commander. However, second-echelon elements found inside the FSCL do not fit in the CAS mission category. In fact, they occupy the hypothetical "no-mission zone" described earlier.
Just as the tactic of echelonment has changed our view of enemy force deployment on the battlefield, so too has there been an evolution in thinking about the interdiction mission. Conceptually, interdiction has always been a mix of attack on enemy forces and attack on transportation infrastructure supporting movement of these forces. But up to the mid-'70s, the main emphasis was on "isolating" the battlefield, reducing the flow of men and materials by attacking the line of communications (LOC) infrastructure. The point was often made that, by contrast with CAS, where effects are immediate, there is a time lag associated with interdiction effects. A good example of this view appears in the March 1973 version of Army Field Manual 100-26, The Air-Ground Operations System:
The effect of an air interdiction campaign seldom is immediately apparent. A coordinated and sustained effort based on sound intelligence and an analysis of the enemy logistic system is required to achieve results.
Naturally, we continue to think of interdiction as involving attacks on LOC infrastructure, but there has been a gradual shift in emphasis, with much more attention now given to attacking enemy main force units as they move to contact. This changing emphasis can be seen in our doctrinal treatment of the interdiction mission. We are now giving much more attention to "battlefield air interdiction" (BAI).
Our concept of BAI––what it is, how it is controlled, etc.––is still evolving.9 As of the end of 1984, TAC and TRADOC had defined BAI as follows:
Air interdiction (AI) attacks against land force targets which have a near-term effect on the operations or scheme of maneuver of friendly forces, but are not in close proximity to friendly forces, are referred to as battlefield air interdiction (BAI). The primary difference between BAI and the remainder of the air interdiction effort is the near-term effect and influence produced against the enemy in support of the land component commander's scheme of maneuver.10
To recapitulate, the second echelon-enemy forces stacked up behind elements in contact–– is the BAI target set. At least some of this target set will be inside the FSCL." Since these enemy forces can already affect friendly ground maneuver, it is not enough to delay or degrade them using the time-honored method of attacking LOC infrastructure. Immediate effects are required. We must attack BAI targets directly, with the purpose of destroying them.12
How are we to attack the BAI target set? What control measures apply? One answer would be to consider BAI targeting a part of the CAS problem. Targets, munitions selection, and attack timing would be the responsibility of the ground commander. Detailed planning and execution control would be done by tactical air control parties (TACPs).
There are a number of good reasons––which can be dealt with here only in outline––why we should not attack the BAI target set within the framework of the CAS system:
It seems clear, on balance, that attacking BAI targets is a kind of interdiction, not a kind of close air support. Moreover, as we have seen, there is no reason not to fly properly coordinated interdiction missions inside the FSCL. But TAC and TRADOC have now moved beyond "coordination" to a concept and procedures that give the ground commander a leading role in selecting and prioritizing BAI targets on both sides of the FSCL. It has been agreed that the senior ground commander will establish a liaison team, the battlefield coordination element (BCE), that will operate inside the tactical air control center. As envisioned by TAC and TRADOC, the battlefield coordination element will comprise approximately thirty Army officers and NCOs organized for two shifts, with duty positions in all main divisions of the TACC. All BAI attacks, on either side of the FSCL, will be "coordinated," in the sense that the ground commander nominates and prioritizes BAI targets and attack timing. The BCE is the agent of the ground commander, the mechanism through which BAI targets are nominated and "coordinated."
However, the impact and influence of the BCE are bound to extend beyond the core function of ensuring that BAI attacks support the ground commander's scheme of maneuver : The BCE increases the prospect that air and ground commanders will share congruent views of the battlefield situation. It ensures that each commander understands the other's near-, mid-, and long-term military objectives, so that, for instance, they can continue to act in harmony even if there is a temporary break in communications. The BCE observes planning and execution for all air activities, including AI to the full depth of theater operations, and will understand (and be able to explain to the commanders of various Army formations) the rationale for the air commander's decisions.
In addition to serving the ground commander's needs inside the tactical air control center, the battlefield coordination element provides important assistance to the air commander. It is the BCE that will "coordinate" AI attacks inside the FSCL that are initiatives of the air side. The BCE will find an important role in coordinating Army fires used to suppress enemy air defenses, as, for example, when we create corridors for air operations across the FLOT. And the BCE will coordinate employment of organic Army assets used in interdiction, ensuring that air and ground interdiction operations are deconflicted and mutually supporting. It seems inevitable, and in my opinion, desirable, that the BCE will eventually involve itself in the planning for virtually all kinds of air activity.14
Today, our basic concept features an airland battlefield of considerable depth, where operational success is achieved by employing well-coordinated ground and air forces.The BCE plays a key role in ensuring that we attack the target set jointly, with jointly agreed objectives and timing. Air Force missions and associated control measures, including the FSCL, need not change. They are flexible enough to accommodate the new approach. But with the introduction of coordinated BAI, we have every reason to expect that our chances of achieving good results in joint operations will be considerably brighter.
Hq USAF
Notes
1. Air Force's Tactical Air Command and the Army's Training and Doctrine Command (TRADOC) have produced joint concepts, doctrine, and procedures since 1975 under the auspices of AirLand Forces Application (ALFA) Agency. ALFA is located at Langley AFB, Virginia. It is manned jointly, with the director position rotating between the services. Among ALFA's more important publications are Joint Air Attack Team Operations (JAAT), Joint Suppression of Enemy Air Defense (J-SEAD), and Joint Attack of the Second Echelon (J-SAK).
2. "CSA/CSAF Initiatives for Action," Attachment to General Charles A. Gabriel. USAF, and General John A. Wickam, Jr., USA, Memorandum of Agreement on U.S. Army-U.S. Air Force Joint Force Development Process, 22 May 1984.
3. Colonel Robert D. Rasmussen, "The Central Europe Battle-Doctrinal Implications for Counterair Interdiction," Air University Review, July-August 1978, pp. 11, 13.
4. Brigadier General Donald R. Morrelli, USA, "FLOT/FEBA Background Information," Memorandum for General Otis, 10 August 1981, on file at Hq TAC/XPJD.
5. Note that, if we credit the definitions, we ought to be able to attack any target between the FLOT and the FSCL without hitting friendly troops.
6. Captain Peter M. Ossorio, USA, "Beyond the No Bomb Line––Fire Support Coordination, 1980's," Military Review, October 1978, The FSCL continues to have some of the character of a bomb line. For instance, the Army's current version of Field Manual 6-20, Fire Support in Combined Arms Operations, puts the FSCL in the category of a "permissive action line," a principal purpose of which is "to expedite the attack of targets beyond" the line, because the requirement to coordinate does not apply.
7. In NATO, this notion is stated concisely in STANAG 2099, Fire Coordination in Supportof Land Forces: "A request by a unit" for air support or additional artillery/naval gunfire on a target short of the FSCL but which has been coordinated with and passed on by the land force command concerned obviates the necessity for further check by the delivery unit.
8. This statement also holds for support of friendly ground forces employed for raids or other deep-maneuver actions beyond the FSCL. Close air support, with all the detailed integration that term implies, will be provided for air attack missions in close proximity of such forces.
9. According to a distinguished former TRADOC commander, the Air Force is "agonizing over this problem." See General William E. Depuy, Toward a Balanced Doctrine," Army, November 1984.
10. USREDCOM Pamphlet 525-8, TRADOC Pamphlet 525-45, TAC Pamphlet 50-29, General Operating Procedures for Joint Attack of the Second Echelon (J-SAK), 31 December 1984, p. 2-7.
11. The depth of the BAI target set is hard to pin down. It seems to me that it rests with the ground commander to determine how far back enemy force elements can be located and still exert a "near-term effect" on friendly operations. A lot of battlefield variables––weather, terrain, enemy force mobility, etc.––will influence this judgment.
12. Our technical capability to interdict LOC infrastructure is fairly good, even at night or in bad weather. Because BAI targets move, and move around-the-clock, we need systems like LANTIRN and IIR Maverick. As we field improved battlefield sensor systems capable of tracking BAI targets in near real time, like J-STARS, we will need to decentralize attack execution; hence, the requirement for a ground attack control center (GACC).
13. An alternative would be to beef up air support operations center capabilities; assign electronic warfare, air-to-air, and other needed expertise; and create a mini-TACC that would have at least some of the technical capabilities required to put together CAS "packages." However, in my judgment, we do not have the resources available to make such a concept workable, even if it is a good idea. It is difficult to imagine such an arrangement working well in, for instance, the Central Region of Europe, where eight allied corps are on line in peacetime.
14. One of the chiefs' thirty-one initiatives––initiative 21––tasks TAC and TRADOC to test the battlefield coordination element concept in order to leave no doubt about our ability to "synchronize" joint action against the BAI target set. As this is written, planning for the appropriate command post exercises and field tests is under way.
Lieutenant General Merrill A McPeak (B.A., San Diego State College; M.A., George Washington University) is Deputy Chief of Staff, Programs and Resources, Hq USAF. A command pilot and parachutist with more than 4000 flying hours, he has also served as assistant chief of staff for current operations, Allied Air Forces Central Europe, acting concurrently as senior representative for commander Allied Air Forces Central Europe and the commander in chief USAF Europe at the Central Region Air Operations Center, Boerfink, Germany. He was Deputy Chief of Staff for Plans, Hq TAC, at Langley AFB, Virginia, when he wrote the article appearing in this issue. General McPeak is a graduate of Armed Forces Staff College and National War College.
Disclaimer
The conclusions and opinions expressed in this document are those of the author cultivated in the freedom of expression, academic environment of Air University. They do not reflect the official position of the U.S. Government, Department of Defense, the United States Air Force or the Air University.
Air & Space Power Home Page | Feedback? Email the Editor