Basic Tactical Control Measures
This article explains basic tactical control measures common to the conduct of offensive and defensive tasks. These control measures apply to both automated and hand-drawn graphic displays and overlays. This article portrays common control measures for use on situation maps, overlays, and annotated aerial photographs. They are also the standard for all simulations, to include those used in live, virtual, and constructive environments.
GENERAL CONSIDERATIONS FOR CONTROL MEASURES
A-1. Units conducting tactical operations must have clearly defined tasks and responsibilities. The commander uses control measures to impose restrictions that prevent units from impeding one another and establish specific responsibilities. Control measures can be permissive (which allows something to happen) or restrictive (which limits how something is done). Control measures may be graphical, such as boundaries, or procedural, such as target engagement priorities. A commander should establish only the minimum control measures necessary to provide essential coordination and deconfliction between units. Control measures must not unduly restrict subordinates in accomplishing their missions. The commander removes restrictive control measures as soon as possible. Control measures can become more restrictive as forces transition from an emphasis on the conduct of offensive and defensive tasks to an emphasis on the conduct of the primary stability or defense support of civil authorities tasks. ADRP 1-02 discusses the rules for drawing control measures on overlays and maps.
A-2. Well-conceived control measures facilitate the conduct of current and future operations. The commander adjusts control measures as necessary to maintain synchronization and ensure mission accomplishment as the tactical situation evolves. The commander balances the risk of introducing additional friction into the operation with the benefits gained by changing them.
A-3. Control measures apply to all forces. The commander ensures that all higher-echelon control measures, such as phase lines (PLs) and checkpoints, are incorporated into the unit’s graphic control measures. The commander references only the control measures established by the higher headquarters when making reports to that headquarters. The commander may or may not chose to establish a standard naming convention for control measures in the unit standard operating procedures (SOPs). Examples of such naming conventions would be reserving car model names for phase lines and female names for objectives. This publication does not use a standard naming convention.
COMMON CONTROL MEASURES
A-4. Paragraphs A-5 through A-70 discuss control measures common to the conduct of all offensive and defensive tasks. Paragraphs A-71 through A-88 discuss control measures common to the conduct of offensive tasks. Finally, paragraphs A-89 through A-106 discuss control measures common to the conduct of defensive tasks.
AIRSPACE COORDINATING MEASURES
A-5. The joint force commander designates an airspace control authority to develop, coordinate, and publish airspace control procedures for operating the airspace control system in the joint operations area. The airspace control authority establishes an airspace control plan that provides specific planning guidance and procedures for the airspace control system for the joint operational area. The airspace control order implements the airspace control plan by providing the details of the approved requests for airspace
coordinating measures (ACMs). It is published either as part of the air tasking order or as a separate document. (See JP 3-52.) These ACMs are measures employed to facilitate the efficient use of airspace to accomplish missions and simultaneously provide safeguards for friendly forces. Airspace elements establish ACMs to accomplish one or more functions:
- Establish reserved airspace for specific airspace users.
- Restrict the actions of some airspace users.
- Create airspace in which units can use weapons with minimal risk of friendly fire incidents. (Friendly fire incidents include death by fratricide, injury, and property damage.)
- Control actions of specific airspace users.
- Require airspace users to accomplish specific actions.A-6. JP 3-52 provides additional information on each of the following joint ACMs:
- Coordinating altitude.
- Low-level transit routes.
- Minimum-risk routes
- Restricted operations areas.
- Special-use airspace.
- High-density airspace control zones.
Standard use Army aviation flight routes.
Figure A-1 shows how some of these joint ACMs are used to create an airspace coordination area.
A-7. The Army, in addition to the seven joint ACMs listed in paragraph A-6, has developed additional standardized ACMs. For Army forces, these measures assign responsibility, ensure conformity with the tactical plan, describe and illustrate the concept of operations, maintain separation of forces, concentrate effort, coordinate fires with maneuver, and assist in the control of forces. Army forces can graphically depict the integration, coordination, regulation, and identification of Army airspace users with ground forces in a given area of operations when they incorporate airspace coordinating measures with these standardized Army ACMs. These Army ACMs are:
- Air corridor.
- Axis of advance.
- Air control point.
- Battle position.
- Engagement area.
- Communications checkpoint.
- Attack by fire position.
- Observation post.
Figure A-2 provides an example air corridor with its associated air control points. FM 3-52 provides additional information on these Army ACMs.
AREA OF OPERATIONS
A-8. An area of operations (AO) is both a basic tactical concept and the basic control measure for all types of operations. An area of operations is an
operational area defined by the joint force commander for land and maritime forces that should be large enough to accomplish their missions and protect their forces (JP 3-0). The joint force land component commander, Army Service component command (ASCC) commander, or Army (ARFOR) commander will in turn assign subordinates their own AOs. Those subordinates will further assign their subordinates AOs down to the battalion or even company echelon based on the mission variables of mission, enemy, terrain and weather, troops and support available, time available, and civil considerations (METT-TC). A unit assigned an AO, although the owning unit, may not change control measures imposed by a higher headquarters within its AO. However, it may establish additional control measures to coordinate and synchronize its operations.
A-9. Assigning an AO to a subordinate headquarters maximizes decentralized execution by empowering subordinate commanders to use their own initiative to accomplish their missions. This encourages the use of mission command. (See ADRP 6-0 for a discussion of mission command.) At the same time it adds the responsibilities listed in paragraph A-12 to the lower headquarters. Conversely, failure to designate subordinate AOs maximizes centralized execution and limits subordinates’ tactical options. The latter choice should be made only when mandated by the mission variables of METT-TC. For example, a brigade combat team (BCT) commander responsible for blocking an enemy advance along a single avenue of approach may assign subordinate battalions battle positions to support a BCT engagement area (EA) instead of subdividing the BCT AO and the avenue of approach into battalion AOs.
A-10. A higher headquarters designates an AO using boundaries. A divisional commander normally assigns AOs to subordinate maneuver units, such as BCTs or maneuver enhancement brigades. However, the commander may also assign an AO to subordinate functional and multifunctional support or sustainment units even though owning an AO is not a task for which these types of units are designed. For example, they lack joint enablers like a tactical air control party. (This non-doctrinal mission for these later types of units is most likely to occur during the conduct of the irregular warfare.) An assigned AO both restricts and facilitates the movement of units and use of fires. It restricts units not assigned responsibility for the AO from moving through the AO. It also restricts outside units from firing into or allowing the effects of their fires to affect the AO. Both of these restrictions can be relaxed through coordination with the owning unit. An assigned AO facilitates the movement and fires of the unit assigned responsibility for, or owning, it. The assigned AO must encompass enough terrain for the commander to accomplish the mission and protect friendly forces.
A-11. Commanders consider a unit’s area of influence when assigning it an area of operations. An area of influence is a geographical area wherein a commander is directly capable of influencing operations by maneuver or fire support systems normally under the commander’s command or control (JP 3-0). A unit’s area of operations should not be substantially larger than its area of influence. Ideally, the entire AO is encompassed by the area of influence. An area of operations that is too large for a unit to control can allow sanctuaries for enemy forces to develop and may limit the unit’s flexibility of operations. If the commander’s area of influence is smaller than the assigned AO, the commander must consider options for extending the size of that area of influence. These options include the following techniques:
- Changing the geographical dispositions of unit current systems to increase the size of the area of influence and ensure coverage of key areas, installations, and systems.
- Requesting additional assets.
- Requesting boundary adjustments to reduce the size of the AO.
- Accepting the increased risk associated with being unable to provide security throughout the AO.
- Moving the area of influence by phases to sequentially encompass the entire AO.A-12. All units assigned an AO have the following responsibilities within the boundaries of that AO:
- Terrain management.
- Intelligence collection.
- Civil affairs activities.
- Air and ground movement control.
- Clearance of fires.
- Personnel recovery.
- Environmental considerations.
(See ADRP 3-90 for a discussion of these responsibilities.)
A-13. An assembly area is an area a unit occupies to prepare for an operation. Ideally, an assembly area (AA) provides—
- Concealment from air and ground observation.
- Adequate entrances, exits, and internal routes.
- Space for dispersion; each AA is separated by enough distance from other AAs to preclude mutual interference.
- Cover from direct fire.
- Good drainage and soil conditions that can sustain unit vehicles and individual Soldier movements.
- Terrain masking of electromagnetic signatures.
- Terrain allowing observation of ground and air avenues into the AA.
Sanctuary from enemy medium-range artillery fires because it is located outside the enemy’s range.
A-14. The commander assigns each unit its own AA. In figure A-3 on page A-5, the example of multiple units occupying one AA is a graphical shortcut taken when the map scale would make depiction of multiple assembly areas unreadable. In reality, the commander would subdivide AA Thomas into two smaller AAs, one for each unit. A unit AA is normally within the AO of another unit. An AA is usually treated as a noncontiguous AO. This means that a unit has the same responsibilities within its assigned AA as it has for any other AO.
A-15. The proper location of AAs contributes significantly to both security and flexibility. The location should facilitate future operations, so movement to subsequent positions can take place smoothly and quickly by concealed routes. Because of their smaller signature, infantry units can use AAs closer to the enemy than armored units without excessive risk of enemy detection. The tactical mobility of armored and Stryker units allows them to occupy AAs at a greater distance from the line of departure (LD) than infantry units.
A-16. A boundary is a line that delineates surface areas for the purpose of facilitating coordination and deconfliction of operations between adjacent units, formations, or areas (JP 3-0). A forward boundary is a boundary of an echelon that is primarily designated to divide responsibilities between it and its next higher echelon. A lateral boundary is a boundary that extends from the rear boundary to the unit’s forward boundary. A rear boundary is a boundary that defines the rearward limits of a unit’s area. It usually also defines the start of the next echelon’s support area. The commander uses graphic control measures to define the limits of an AO and, as such, establishes ground forces’ responsibilities. The
ACMs control the vertical dimension. The commander bases the boundaries of subordinate units on clearly defined terrain features. This requirement is less important if all units in the AO have precision navigation capabilities. Boundaries should not split responsibilities for roads, rivers, or railways. Responsibility for an avenue of approach and key terrain should also belong to only one unit. The commander adjusts boundaries as necessary in response to the evolving tactical situation. Any areas not delegated to a subordinate remain the responsibility of the commander.
A-17. After military characteristics of the terrain are accounted for within the context of the unit’s mission, existing political boundaries, such as city limits and provincial borders, are important considerations in developing friendly unit graphical control measures and assigning subordinate unit AOs. Military boundaries that conflict or do not align with existing political boundaries require additional effort when trying to deconflict, manage, or organize the use of indigenous capabilities. However, during the conduct of protracted operations within an AO, subordinate unit AOs should be
periodically adjusted to avoid the inadvertent creation of sanctuaries that an enemy could exploit.
A-18. A checkpoint is a predetermined point on the ground used to control movement, tactical maneuver, and orientation (ADRP 1-02). Units can also use a checkpoint as a fire control measure in lieu of the preferred control measure, a target reference point. Checkpoints are useful for orientation. Units may use checkpoints to supplement or as substitutes for PLs. They are also used in the conduct of sustainment
operations. Figure A-4 depicts checkpoint 13.
A-19. In land warfare, a contact point is a point on the terrain, easily identifiable, where two or more ground units are required to make physical contact (JP 3-50). A commander establishes a contact point where a PL crosses a lateral boundary or on other identifiable terrain as a technique to ensure coordination between two units. The commander provides a date-time group to indicate when to make that physical contact. Figure A-5 depicts contact point 8.
A-20. The mutual higher commander of two moving units normally designates the location of contact points and times of contact. When one unit is stationary, its commander normally designates the location
Figure A-5. Contact point 8
of the contact point and the meeting time, and transmits this information to the commander of the moving unit.
CRITICAL FRIENDLY ZONE
A-21. A critical friendly zone is an area, usually a friendly unit or location, which the maneuver commander designates as critical to the protection of an asset whose loss would seriously jeopardize the mission (ADRP 1-02). A critical friendly zone (CFZ) is one of four different types of zones used with field artillery target acquisition radars. Typical CFZs include maneuver assembly areas, command posts, forward arming and refueling points, friendly breaching sites, and other troop concentrations. The exact size and shape of the CFZ reflects the technical characteristics of the
sensor coverage and varies in accordance with the terrain. Figure A-6 shows a CFZ for a BCT. The designation of a CFZ requires the availability of target acquisition radars to cover the designated area and fire support weapon systems to conduct counterfire. (JP 3-09 defines counterfire as fire intended to destroy or neutralize enemy weapons. Includes counterbattery and countermortar fire.) The supporting field artillery unit’s automated fire support system is tied to that sensor to place the location of a weapon firing into the CFZ ahead of all other targets in priority for counterfire. This results in an immediate call for fire unless the system operator manually overrides the automated request for fire. The other three types of radar zones are call-for-fire zone, artillery target intelligence zone, and censor zone. (For additional information on the employment of all four of these radar zones, see FM 3-09.12.)
DIRECT FIRE CONTROL MEASURES
A-22. The small-unit commander communicates to subordinates the manner, method, and time to initiate, shift, and mass fires, and when to disengage by using direct fire control measures. The commander should control unit fires to direct the engagement of enemy systems to gain the greatest effect. The commander uses intelligence preparation of the battlefield (IPB) products and reconnaissance to determine the most advantageous way to use direct fire control measures to mass the effects on the enemy and reduce friendly fire incidents from direct fire systems. The commander must understand the characteristics of weapon systems and available munitions (such as the danger to unprotected Soldiers when tanks fire discarding sabot ammunition over their heads or near them). Direct fire control measures defined in this publication include engagement criteria, engagement priorities, sectors of fire, and target reference points (TRPs). Maneuver platoon and company publications address other direct fire control measures, such as frontal, cross, or depth fire patterns and simultaneous, alternating, or observed techniques of fire.
A-23. An engagement area is an area where the commander intends to contain and destroy an enemy force with the massed effects of all available weapons and supporting systems. This includes organic direct fire systems and supporting systems, such as close air support. Figure A-7 depicts several EAs used within the context of a battalion defense. The commander determines the size and shape of the EA by the relatively unobstructed line-of-sight from the weapon systems in their firing positions and the maximum range of those weapons. The commander designates EAs to cover each enemy avenue of approach into unit positions. The commander also can use them to designate known or suspected enemy locations. The commander selects EAs and then arrays available forces and weapon systems in positions to concentrate overwhelming effects into these areas. The commander routinely subdivides EA into smaller EAs for subordinates using one or more target reference points or by prominent terrain features. The commander assigns sectors of fires to subordinates to prevent friendly fire incidents, but responsibility for an avenue of approach or key terrain is never split. These sectors normally do not affect friendly maneuver. Commanders of units up to battalion task force size normally use this control measure. (See FM 90-7 for a discussion of EA development.)
A-24. Engagement criteria are protocols that specify those circumstances for initiating engagement with an enemy force. They may be restrictive or permissive. For example, a company commander could tell the 1st Platoon to wait until three enemy tanks reach a target reference point within its EA before initiating fire. Another example is a battalion commander telling a company commander not to engage an approaching enemy unit until it commits itself to an avenue of approach. The commander establishes engagement criteria in the direct fire plan. Commanders and leaders of small tactical units use engagement criteria in conjunction with engagement priorities and other direct fire control measures to mass fires and control fire distribution.
A-25. Engagement priority specifies the order in which the unit engages enemy systems or functions. The commander assigns engagement priorities based on the type or level of threat at different ranges to match organic weapon systems capabilities against enemy vulnerabilities. Engagement priorities are situationally dependent. The commander uses engagement priorities to distribute fires rapidly and effectively. Subordinate elements can have different engagement priorities. For example, the commander establishes engagement priorities so that M2 Bradley fighting vehicles engage enemy infantry fighting vehicles or armored personnel carriers, while M1 Abrams tanks engage enemy tanks. Normally, units engage the most dangerous targets first, followed by targets in depth or specialized systems, such as engineer vehicles.
A-26. A sector of fire is that area assigned to a unit, a crew-served weapon, or an individual weapon within which it will engage targets as they appear in accordance with established engagement priorities. (See figure A-8 on page A-8.) Battalions and smaller echelons primarily use this direct fire control measure. Each sector of fire can extend from a firing position to the maximum engagement range of the weapon, or it can be an enclosed area at a distance from the firing position. The commander should assign each subordinate unit or available weapon system a primary sector of fire and a secondary sector of fire to increase the capability of concentrating fire in certain areas. The primary sector of fire is that area in which the assigned unit, individual, or crew-served weapon is initially responsible for engaging and destroying enemy targets located in that sector in accordance with established priorities for engagement. Fire shifts to the secondary sector, on order, when there are no targets in the primary sector, or when the commander needs to cover the movement of another friendly element. This secondary sector
of fire should correspond to another element’s primary sector of fire to obtain mutual support. Subordinate commanders may impose additional fire control measures as required.
A-27. A target reference point is An easily recognizable point on the ground (either natural or man-made) used to initiate, distribute, and control fires (ADRP 1-02). Target reference points (TRPs) can also designate the center of an area where the commander plans to distribute or converge the fires of all his weapons rapidly. They are used by task force and below, and can further delineate sectors of fire within an engagement area. TRPs are designated using the standard target symbol and numbers issued by the fire support officer. Once designated, TRPs may also constitute indirect fire targets. A TRP may be a natural terrain feature, a man-made artifact, such as a building, or a marker emplaced by the unit. Maneuver leaders at battalion and below designate TRPs to define unit or individual sectors of fire and observation, usually within an
EA. A TRP can also designate the center of an area where the commander plans to rapidly distribute or converge fires. A task force commander designates TRPs for subordinate company teams. Company commanders designate TRPs for their platoons, sections, and, in some cases, individual weapons. Platoon leaders or subordinate leaders may designate additional TRPs for their elements as necessary to control direct and indirect fires. The echelon fire support officer can also designate TRPs as indirect fire targets by using the standard target symbol and target numbering identification (two letters and four numbers). (See FM 3-60 for additional information on indirect fire target numbering.) The TRP is designated using numeric-only marking only if the TRP is not also used as an indirect fire target. Figure A-9 depicts the symbol for TRP 032, a direct-fire only target reference point. The rest of the TRPs in the figures in this publication are both direct- and indirect fire targets and thus designated using indirect fire symbology.
A-28. A trigger line is A phase line located on identifiable terrain that crosses the engagement area—used to initiate and mass fires into an engagement area at a predetermined range for all or like weapon systems (ADRP 1-02). It is located on identifiable terrain—like all phase lines—that crosses an EA, a direction of attack, or an axis of advance. The commander can designate one trigger line for all weapon systems or separate trigger lines for each weapon or type of weapon system. The commander specifies the engagement criteria for this specific situation. The criteria may be either time- or event-driven, such as a certain number or certain types of vehicles to cross the trigger line before initiating engagement. The commander can use a time-based fires delivery methodology or a geography based fires delivery. The commander may reserve the authority to initiate engagement by firing the commander’s own individual weapon or giving the command to fire.
A-29. The commander designates a PL as the trigger line for available supporting fire support systems. The commander bases the location of the trigger line on the mission variables of METT-TC, including such variables as the time of flight for artillery shells, positioning of the guns, and the existence of quick-fire links. Its location varies from situation to situation. Its position reflects the distance an enemy force is likely to traverse in the time it takes from when fires are requested to when artillery rounds impact, at a given enemy’s movement speed. (See figure A-10.) This gives time for supporting fire support systems to respond to the initial call for fire. For example, in a desert environment—for enemy forces traveling at speed X, a battalion task force commander’s fire support
trigger line is approximately four kilometers beyond the point where the commander wants to engage the enemy with indirect fires when M109A6 howitzers are in direct support. It is approximately six kilometers when M109A3 howitzers are in direct support. The shorter distance reflects the generally more rapid response capabilities of the M109A6.
A-30. The commander can establish another trigger line for the unit’s most accurate long-range weapon system in the vicinity of the area where the fire support impacts to capitalize on the asymmetric attack. However, dust and debris resulting from the artillery fire may prevent direct-fire systems from engaging the enemy. The commander establishes other trigger lines and TRPs for shorter-range systems. The commander may give guidance to extremely proficient crews to engage the enemy at longer than normal ranges or give them different engagement priorities than the rest of the force, such as giving priority to engaging air defense or engineer-breaching systems.
A-31. When the enemy reaches these closer trigger lines, the commander establishes a decision point to help force a determination on whether the commander wants available longer-range systems to continue to fire in depth or to concentrate unit fires on a single point. Many factors impact this decision, most of which concern the enemy and how the enemy maneuvers and the effects of the defending force’s fires.
FIRE SUPPORT COORDINATION MEASURES
A-32. Commanders assigned an AO employ fire support coordination measures (FSCMs) to facilitate rapid target engagement and simultaneously provide safeguards for friendly forces. FSCMs are either permissive or restrictive. Boundaries are the basic FSCM. The fire support coordinator recommends FSCMs to the commander based on the commander’s guidance, location of friendly forces, scheme of maneuver, and anticipated enemy actions. Once established, they are entered into or posted on all the command’s displays and databases. (ADRP 3-09 explains the use of all FSCMs in more detail).
A-33. The primary purpose of permissive measures is to facilitate the attack of targets. Once they are established, further coordination is not required to engage targets affected by the measures. Permissive FSCMs include a coordinated fire line (CFL), a fire support coordination line (FSCL), and a free-fire area (FFA).
A-34. A coordinated fire line is a line beyond which conventional and indirect surface fire support means may fire at any time within the boundaries of the establishing headquarters without additional coordination. The purpose of the coordinated fire line is to expedite the surface-to-surface attack of targets beyond the coordinated fire line without coordination with the ground commander in whose area the targets are located (JP 3-09). BCTs or divisions usually establish a CFL, although a maneuver battalion may establish one. It is located as close as possible to the establishing unit without interfering with maneuver forces to open up the area beyond the CFL to fires. A higher echelon may consolidate subordinate unit CFLs. If this occurs, any changes to the subordinate CFLs are coordinated with the subordinate headquarters. (See figure A-11.)
A-35. The fire support coordination line is a fire support coordination measure that is established and adjusted by appropriate land or amphibious force commanders within their boundaries in consultation with superior, subordinate, supporting, and affected commanders. Fire support coordination lines facilitate the expeditious attack of surface targets of opportunity beyond the coordinating measure. A fire support coordination line does not divide an area of operations by defining a boundary between close and deep operations or a zone for close air support. The fire support coordination line applies to all fires of air, land, and sea-based weapon systems using any type of ammunition. Forces attacking targets beyond a fire support coordination line must inform all affected commanders in sufficient time to allow necessary reaction to avoid fratricide. Supporting elements attacking targets beyond the fire support coordination line must ensure that the attack will not produce adverse effects on, or to the rear of, the line. Short of a fire support coordination line, all air-to-ground and surface-to-surface attack operations are controlled by the appropriate land or amphibious force commander. The fire support coordination line should follow well-defined terrain features. Coordination of attacks beyond the fire
Figure A-11. 1st Brigade combat team coordinated fire line
Figure A-12. III Corps fire support coordination line
support coordination line is especially critical to commanders of air, land, and special operations forces. In exceptional circumstances, the inability to conduct this coordination will not preclude the attack of targets beyond the fire support coordination line. However, failure to do so may increase the risk of fratricide and could waste limited resources (JP 3-09). (See figure A-12.)
A-36. The commander designating a FSCL remains responsible for establishing the priority, effects, and timing of fires impacting beyond the FSCL. Coordination for attacks beyond the FSCL is through the air tasking order. The appropriate land or amphibious commander controls attacks short of the FSCL. Army commanders use the tactical air control system or the Army air-ground system to control the execution of close air support (CAS). By establishing a FSCL close-in, yet at sufficient depth so as to not limit high tempo maneuver, land and amphibious force commanders ease the coordination requirements for engagement operations within their AOs by forces not under their control, such as naval surface fire support or air interdiction.
A-37. A free-fire area is a specific area into which any weapon system may fire without additional coordination with the establishing headquarters (JP 3-09). Normally, division or higher headquarters establish a FFA on identifiable terrain. (See figure A-13.)
A-38. A restrictive FSCM prevents fires into or beyond the control measure without detailed coordination. The primary purpose of restrictive measures is to provide safeguards for friendly forces. Restrictive FSCM include an airspace coordination area, a no-fire area (NFA), a restrictive fire area (RFA), and a restrictive fire line (RFL). Establishing a restrictive measure imposes certain requirements for specific coordination before the engagement of those targets affected by the measure. (See FM 3-52 for a description of an airspace coordination area.)
A-39. A no-fire area is an area designated by the appropriate commander into which fires or their effects are prohibited (JP 3-09.3). (See figure A-14.) A commander uses a NFA to protect independently operating elements, such as forward observers and special operations forces. The commander can also use it to protect friendly forces in the echelon support area and for humanitarian reasons, such as preventing the inadvertent engagement of displaced civilian concentrations, or to protect sensitive areas, such as cultural monuments. This rule has two exceptions:
- The establishing headquarters may approve fires within the NFA on a case-by-case mission
Figure A-13. 1CD free-fire area basis.
- When an enemy force within a NFA engages a friendly force, the friendly force may engage a positively identified enemy force to defend itself.
A-40. A restrictive fire area is an area in which specific restrictions are imposed and into which fires that exceed those restrictions will not be delivered without coordination with the establishing headquarters (JP 3-09). (See figure A-15.) The purpose of the RFA is to regulate fires into an area according to the stated restrictions, such as no unguided conventional or dud-producing munitions. Maneuver battalion or larger ground forces normally establish RFAs. On occasion, a company operating independently may establish a RFA. Usually, it is located
Figure A-15. Example restrictive fire area
on identifiable terrain, by grid or by a radius (in meters) from a center point. The restrictions on a RFA may be shown on a map or overlay, or reference can be made to an operation order that contains the restrictions.
A-41. A restrictive fire line is a line established between converging friendly surface forces that prohibits fires or their effects across that line (JP 3-09). Both or only one of those converging forces may be moving. Fires and their effects can cross a RFL when the event has been coordinated with the establishing and affected organizations. The purpose of the line is to prevent interference between converging friendly forces, such as what occurs during a linkup operation. The next higher common commander of the converging forces establishes the RFL. Located on identifiable terrain, it is usually located closer to the stationary force—if there is one—than to the moving force. Alternatively, the commander can use a RFL to protect sensitive areas, such as cultural monuments. (See figure A-16.)
A-42. In the fire support context, a target is an area designated and numbered for future firing (JP 3-60). There are control measures for point targets, circular targets, rectangular targets, and linear targets. Figure A-17 depicts these symbols. The commander designates fire support targets using a two-letter and four-digit code established in field artillery doctrine. The commander may group two or more targets for simultaneous engagement. This is called a “group of targets.” A group of targets is graphically shown by circling the targets and identifying the group with a group designator. This group designator consists of the two letters assigned to the block of target numbers assigned to a unit with a number inserted between the two letters. The commander may also attack individual targets and groups of targets in series or in a predetermined sequence. When this occurs, it is referred to as a “series of targets”. Graphically, a series of targets is shown as individual targets or groups of targets within a prescribed area. The series is assigned a code name or
Figure A-17. Fire support target symbols
nickname. The fact that a series or group of targets has been designated does not preclude the attack of individual targets within the series or group. It also does not preclude the attack of one or more groups of targets within the series.
A-43. Doctrine classifies each fire support target as either a planned target or a target of opportunity. Targets of opportunity are not planned in advance and are engaged as they present themselves in accordance with established engagement criteria and rules of engagement. Planned targets are ones on which fires are prearranged, although the degree of this prearrangement may vary.
A-44. Individually planned fire support targets may be further subdivided into scheduled and on-call fires. Scheduled targets are planned targets on which field artillery and other fire support assets deliver their fires in accordance with a pre-established time schedule and sequence. On-call targets are planned targets engaged in response to a request for fires rather than in accordance with an established time schedule. An on-call target requires less reaction time than a target of opportunity. The degree of prearrangement for the on-call target influences the reaction time from request to execution–the greater the prearrangement, the faster the reaction time. Priority targets are an example of on-call targets that have short reaction times, since each priority target has a fire unit placed on it when it is not engaged in other fire missions. The final protective fires (FPFs) of A Battery, 1st Battalion 16th Field Artillery in figure A-17 above is an example of a priority target. (See ADRP 3-09 for additional information regarding fire support.)
A-45. Time-sensitive targets are not area targets designated and numbered for future firing. A time-sensitive target is a joint force commander designated target requiring immediate response because it is a highly lucrative, fleeting target of opportunity or it poses (or will soon pose) a danger to friendly forces (JP 3-60).
FORWARD LINE OF OWN TROOPS
A-46. The forward line of own troops is a line which indicates the most forward positions of friendly forces in any kind of military operation at a specific time (JP 3-03). The forward line of own troops (FLOT) normally identifies the forward location of covering and screening forces. In the defense, it may be beyond, at, or short of the forward edge of the battle area (FEBA), depending on the tactical situation. It does not include small, long-range reconnaissance assets and similar stay-behind forces. Friendly forces forward of the FLOT may have a restrictive fire coordination measure, such as an RFA, placed around them to preclude friendly fire incidents. Figure A-18 depicts the symbol for the FLOT.
LINE OF CONTACT
A-47. The line of contact is a general trace delineating the location where friendly and enemy forces are engaged. The commander designates the enemy side of the line of contact (LC) by the abbreviation “ENY.” In the defense, a LC is often synonymous with the FLOT. In the offense, a LC is often combined with the LD. Chapter 4 discusses the LD. Figure A-19 depicts the symbol for the LC.
A-48. A movement corridor is a designated area established to protect and enable ground movement along a route (FM 3-90.31). Units establish a
Figure A-19. Line of contact
movement corridor to set the conditions to protect and enable movement of traffic along a designated surface route. Units conduct synchronized operations within the movement corridor such as reconnaissance, security, mobility, and information engagement for forces that require additional mission command, protection, and support to enable their movement. A movement corridor may be established to facilitate the movement of a single element or be established for a longer period of time to facilitate the movement of a number of elements along a given route. The owner of an AO may establish a movement corridor within that AO along an established main supply route or a route designated for a unit’s movement. The movement corridor would typically include the airspace above it to allow the establishing unit to conduct aerial reconnaissance and fires. Figure A-20 on page A-14 depicts a movement corridor.
NAMED AREA OF INTEREST
A-49. A named area of interest is the geographical area where information that will satisfy a specific information requirement can be collected (ADRP 1-02). Named areas of interest (NAIs) are usually selected to capture indications of enemy courses of action but also may be related to battlefield and environmental conditions. In this later case, the NAI may actually be a person, group, or portion of cyberspace. The commander tailors the shape of the NAI symbol to the actual area the commander wants observed, rather than using a prescribed shape. It is possible to redesignate a NAI as a targeted area of interest or a target area of interest (TAI) on confirmation of
enemy activity within the area, allowing a commander to mass the effects of combat power on that area. Figure A-21 depicts NAI Augusta.
OBSTACLE CONTROL MEASURES
A-50. An obstacle is any natural or man-made obstruction designed or employed to disrupt, fix, turn, or block the movement of an opposing force, and to impose additional losses in personnel, time, and equipment on the opposing force (JP 3-15). Obstacles can be natural or man-made, or a combination of both. Forces emplace tactical and protective obstacles that reinforce terrain restrictions and existing obstacles, and integrate them with fires to affect enemy movement or maneuver and shape engagements. Obstacle control measures are specific measures that simplify the granting of obstacle-emplacing authority while providing obstacle control. They consist of—
Figure A-22 summarizes these control measures. A commander assigned an AO can only emplace protective obstacles unless authorized by that individual’s higher echelon commander.
A-51. Analysis of the higher headquarters’ mission and commander’s intent identifies information that may impact the mission. The components of this analysis are intent, AOs, military deception, directed and implied tasks, limitations, available assets, risk, and emplacement timelines and risk. Among the directed obstacle tasks are the planning, preparation, and execution of reserve obstacles. Reserve obstacles allow the force to retain control over the mobility along a given avenue of approach. FM 90-7 discusses engagement area development and obstacle integration.
A-52. An obstacle zone is a division-level command and control measure, normally done graphically, to designate specific land areas where lower echelons are allowed to employ tactical obstacles (JP 3-15). Corps and division commanders use them to grant obstacle-emplacement authority to brigades (including other major subordinate units). Obstacle zones are permissive, allowing a BCT to place reinforcing obstacles to support their scheme of maneuver without interfering with future operations.
A-53. If the obstacle zone encompasses the entire BCT AO, another graphic is unnecessary. Commanders may designate the entire AO as an obstacle zone, with the unit boundaries defining the geographical limits of the zone. Obstacle zones do not cross BCT boundaries. Commanders assign obstacle zones to a single subordinate unit to ensure unity of effort, just as they would when assigning defensive AOs or battle positions. This keeps tactical obstacle responsibility along the same lines as control of direct and indirect fires. This does not normally create vulnerabilities on the boundary between units since the commander bases the assignment of both subordinate AOs and obstacle zones on defined avenues of approach.
A-54. A commander does not normally assign an obstacle effect (block, fix, turn, or disrupt) to an obstacle zone. This allows subordinate commanders flexibility in using obstacles. The commander should establish construction and resourcing priorities between different obstacle zones.
A-55. An obstacle belt is a brigade-level command and control measure, normally given graphically, to show where within an obstacle zone the ground tactical commander plans to limit friendly obstacle employment and focus the defense (JP 3-15). It assigns an intent to the obstacle plan and provides the necessary guidance on the overall effect of obstacles within a belt. Commanders plan obstacle belts within assigned obstacle zones to grant obstacle-emplacement authority to their major subordinate units. Obstacle belts also focus obstacles to support the brigade scheme of maneuver and ensure that obstacles do not interfere with the maneuver of any higher headquarters.
A-56. Obstacle belts are restrictive, but also direct a subordinate unit to construct one or more obstacles to create an effect in the area. They do not specify the type or number of obstacles. Obstacle belts do not cross unit boundaries for the same reasons discussed in obstacle zones. A single unit is responsible for a belt; however, a commander may assign more than one belt to a unit.
A-57. A BCT commander normally assigns an obstacle effect and priority to each obstacle belt. As with the obstacle zone, the target and relative location are apparent. Adding a specific obstacle effect gives purpose and direction to subordinate battalion obstacle planning. When BCT commanders assign an obstacle effect, they ensure that obstacles within the belt complement the BCT fire plan.
A-58. A corps, division, or brigade commander may authorize emplacement authority for certain types of protective obstacles outside of obstacle zones or belts. Normally, the commander authorizes company team and base commanders to emplace protective obstacles within 500 meters of their positions, depending on the mission variables of METT-TC. The commander usually limits the types of obstacles a unit may use for protective obstacles that are outside of obstacle-control measures. For example, the commander may allow only wire- and command-detonated mines outside of control measures for protective obstacles. Furthermore, the commander may require that minefields be fenced on all sides to prevent friendly fire incidents, after obtaining legal guidance concerning current rules and policies on mine emplacement.
A-59. Obstacle groups are one or more individual obstacles grouped to provide a specific obstacle effect. Task forces use obstacle groups to ensure that company teams emplace individual obstacles supporting the task force’s scheme of maneuver. In rare cases, brigades, divisions, or even corps may use obstacle groups for specific tactical obstacles. Also, units integrate obstacle groups with their direct- and indirect-fire plans. Brigade and maneuver battalion commanders can plan their placement anywhere in the obstacle zones or belts, respectively.
A-60. Unlike obstacle zones or belts, obstacle groups are not areas but relative locations for actual obstacles. Commanders normally show obstacle groups using the obstacle-effect graphics. When detailed planning is possible (to include detailed on-the-ground reconnaissance), commanders may show obstacle groups using individual obstacle graphics.
A-61. The company team commander and the engineer can adjust obstacles in the group if the intent and link to the fire plan remain intact. Company team commanders make minor changes to obstacles and fire-control measures based on terrain realities. For example, a commander may move a fixing obstacle group and direct-fire TRPs a hundred meters to avoid having them masked by rolling terrain. However, a major change to the obstacle group location requires the approval of the commander who ordered the obstacle group emplacement.
A-62. Each type of individual obstacle, such as abatis, antitank ditchs, booby traps, mines and minefields, roadblocks, craters, and wire obstacles has its associated graphic. Once a unit constructs an individual obstacle, the obstacle’s location is recorded and reported through the chain of command. Commanders must report individual obstacles in sufficient detail so that any unit moving through the area can bypass or reduce the obstacle without excessive risk. Each headquarters is responsible to ensure exact obstacle locations are disseminated throughout its organization. Individual obstacle graphics are rarely shown on maps above the battalion echelon and are not depicted in this publication. (Maneuver Support Center of Excellence publications describe individual obstacles and establish their associated symbols.)
A-63. Commanders may use obstacle restrictions to provide additional obstacle control and to limit the specific types of obstacles used, such as restricting the use of buried mines. These restrictions ensure that subordinates do not use obstacles with characteristics that impair future operations. These restrictions also allow commanders to focus the use of limited resources for the decisive operation by restricting their use elsewhere. An obstacle restricted area is a command and control measure used to limit the type or number of obstacles within an area (JP 3-15). The commander with emplacement authority uses obstacle restricted areas (ORAs) to restrict obstacle placement. The ORA graphic depicts the impacted area, the unit imposing the restriction, and the restrictions in effect.
A-64. A phase line is a line utilized for control and coordination of military operations, usually an easily identified feature in the operational area (JP 3-09). (See figure A-23 on page A-18.) A commander establishes PLs to control the maneuver of the units. Phase lines are not boundaries unless designated as such and do not establish any specific responsibilities between units, unless the operations order so specifies. When possible, the commander places them along easily recognizable terrain features—such as roads, railroad tracks, rivers, and ridgelines—to ensure easy identification. As with boundaries, this is less important if all units are equipped with precision navigation devices, such as global positioning systems (GPS). Some PLs have additional designations for specific purposes, such as a LD or a probable line of deployment (PLD).
POSITION AREA FOR ARTILLERY
A-65. A position area for artillery is an area assigned to an artillery unit where individual artillery systems can maneuver to increase their survivability. A position area for artillery is not an area of operations for the artillery unit occupying it. The commander assigns position areas for artillery (PAAs) for terrain management purposes. Establishing a PAA lets other subordinate units know they should avoid occupying that same terrain, thus avoiding enemy counterfire. While the exact size of a PAA depends on the mission variables of METT-TC, a Paladin platoon normally requires a PAA encompassing over four square kilometers, and a Multiple Launch Rocket System (MLRS) platoon requires nine square kilometers. (See figure A-24 on page A-18.)
A-66. The maneuver echelon operations officer (G-3 or S-3) of the unit that owns the terrain establishes the PAA. The occupying artillery unit does not have the same authority and responsibilities toward the PAA that are associated with a unit assigned an AO. For example, other units can move through a PAA without clearing that movement with the artillery unit. The artillery unit occupying a PAA establishes liaison with the unit that owns the AO where the PAA is located. The echelon fire support officer usually conducts this liaison in accordance with standard command and support relationships. (For a discussion of common command and support relationships,
see ADP 3-0. For a discussion of artillery missions, see ADRP 3-09.)
A-67. The decision to establish a PAA affects airspace control for
Figure A-24. Position area for artillery rotary-, fixed-wing, and tilt-rotor aircraft integration. A PAA is a base upon which to establish future grid-target lines for lateral deconfliction and areas for rotary-, fixed-wing, and tilt rotor aircraft to avoid, depending on high- or low-angle artillery fires.
A-68. A route is the prescribed course to be traveled from a specific point of origin to a specific destination. (See Route Iron in figure A-25.) Routes can have different functions. Those functions can be added as adjectives to specify different types of routes. Examples of such routes include a passing route and a main supply route (MSR). The commander can further designate MSRs as open, supervised, dispatch, reserved, or prohibited. The commander can assign names, numbers, or alphanumeric designations to routes within the AO. (See FM 3-34.170 for additional information concerning route classification and marking.)
TARGET AREA OF INTEREST
A-69. A target area of interest is the geographical area where high-value targets can be acquired and engaged by friendly forces. Not all target areas of interest will form part of the friendly course of action; only target areas of interest associated with high priority targets are of interest to the staff. These are identified during staff planning and wargaming. Target areas of interest differ from engagement areas in degree. Engagement areas plan for the use of all available weapons; target areas of interest might be engaged by a single weapon. (JP 2-01.3) Not all target areas of interest will form part of the friendly course of action; only target areas of interest associated with high priority targets are of interest to the staff. The commander designates a target area of interest where subordinate friendly weapon systems can best attack high-payoff targets. The unit staff develops these target areas of interest during the targeting
process, based on the currently available products resulting from the IPB process. These target areas of interest are further refined during wargaming and finally approved by the commander during course of action approval. The shape of a target area of interest reflects the type of target and the weapon system intended to engage that target. They are normally cued by surveillance assets, which include unmanned aircraft system (UAS), combat observation and lasing teams (COLTs), long-range surveillance teams, fixed-wing reconnaissance aircraft using a variety of sensors, and special operations forces. A commander can designate a target area of interest for any organic or supporting systems, including close air support. Target areas of interest differ from engagement areas in degree. Commanders plan EAs for the use of all available weapons, while TAIs might be engaged by only a single weapon system. Figure A-26 depicts TAI Whitetail.
A-70. The Army term targeted area of interest is the geographical area or point along a mobility corridor where successful interdiction will cause the enemy to abandon a particular course of action or require the enemy to use specialized engineer support to continue. It is where the enemy force can be acquired and engaged by friendly forces (ADRP 1-02).
COMMON OFFENSIVE CONTROL MEASURES
A-71. This section defines in alphabetical order those common offensive control measures commanders use to synchronize the effects of combat power. The commander uses the minimum control measures required to successfully complete the mission while providing subordinates the flexibility needed to respond to changes in the situation.
A-72. An assault position is a covered and concealed position short of the objective from which final preparations are made to assault the objective. (ADRP 3-90). These final preparations can involve tactical considerations, such as a short halt to coordinate the final assault, reorganize to adjust to combat losses, or make necessary adjustments in the attacking force’s dispositions. These preparations can also involve technical items, such as engineers conducting their final prepare-to-fire checks on obstacle clearing systems and the crews of plow- and roller-equipped tanks removing their locking pins. An assault position may be located near either a final coordination line (FCL) or a probable line of deployment (PLD). (Paragraphs A-79 and A-84 define a FCL and a PLD respectively.)
A-73. The assault time establishes the moment to attack the initial objectives throughout the geographical scope of the operation (ADRP 3-90). It is imposed by the higher headquarters in operations to achieve simultaneous results from several different units. It synchronizes the moment the enemy feels the effects of friendly combat power. It is similar to the time-on-target control method for fire mission processing used by the field artillery. A commander uses it instead of a time of attack (see paragraph A-87) because of the different distances that elements of the commander’s force must traverse, known obstacles, and differences in each unit’s tactical mobility.
A-74. An attack by fire position designates the general position from which a unit conducts the tactical task of attack by fire (ADRP 3-90). (Appendix B defines the tactical mission task of attack by fire.) The purpose of these positions is to mass the effects of direct fire systems for one or multiple locations toward the enemy. An attack by fire position does not indicate the specific site. Attack by fire positions are rarely applicable to units larger than company size. Figure A-27 depicts attack by fire position BRANDON.
A-75. The attack position is the last position an attacking force occupies or passes through before crossing the line of departure (ADRP 3-90). An attack position facilitates the deployment and last-minute coordination of the attacking force before it crosses the
LD. It is located on the friendly side of the LD and offers cover and concealment for the attacking force. It is used primarily at battalion level and below. Whenever possible, units move through the attack position without stopping. An attacking unit occupies an attack position for a variety of reasons, including, for example, when the unit is waiting for specific results from preparation fires or when it is necessary to conduct additional coordination, such as a forward passage of lines. If the attacking unit occupies the attack position, it stays there for the shortest amount of time possible to avoid offering the enemy a lucrative target. (Figure A-28 shows attack positions BLUE and GOLD used in conjunction with other common offensive control measures.)
Axis of Advance
A-76. An axis of advance designates the general area through which the bulk of a unit’s combat power must move (ADRP 3-90). When developing the axis of advance, the commander also establishes bypass criteria. Bypass criteria are measures during the conduct of an offensive operation established by higher headquarters that specify the conditions and size under which enemy units and contact may be avoided (ADRP 3-90). There are three primary reasons why a commander uses an axis of advance:
- First, to direct the bypass of locations that could delay the progress of the advancing force, such as known contaminated areas.
- Second, to indicate that the force is not required to clear the AO as it advances. The force will be required to clear the axis in accordance with specified bypass criteria.
- The third primary reason is to indicate to a unit involved in offensive encirclement, exploitation, or pursuit operations the need to move rapidly toward an objective.
When using an axis of advance there is always the risk that enemy forces outside the axis not being detected and being inadvertently bypassed. Figure A-28 depicts axis of advance JAN.
A-77. The battle handover line is a designated phase line on the ground where responsibility transitions from the stationary force to the moving force and vice versa (ADRP 3-90). The common higher commander of the two forces establishes the battle handover line (BHL) after consulting both commanders. The stationary commander determines the location of the line. The BHL is forward of the forward edge of the FEBA in the defense or the FLOT in the offense. The commander draws it where elements of the passing unit can be effectively supported by the direct fires of the forward combat elements of the stationary unit until passage of lines is complete. The area between the BHL and the stationary force belongs to the stationary force commander. The stationary force commander may employ security forces, obstacles, and fires in the area. Figure A-29 depicts a BHL used in conjunction with other control measures for a rearward passage of lines.
A-78. The direction of attack is a specific direction or assigned route a force uses and does not deviate from when attacking (ADRP 3-90). It is a restrictive control measure. The commander’s use of a direction of attack maximizes control over the subordinate unit movement, and is often used during night attacks, infiltrations, and when attacking through smoke. The commander establishes a direction of attack through a variety of means, such as target reference points, checkpoints, GPS way points, and using sensors, such as ground surveillance radar to track the attack force and target acquisition radars to track the impact of artillery shells. Target reference points placed on recognizable terrain provide the commander with the capability to rapidly shift fires and reorient subordinate maneuver forces. When using a direction of attack, the commander designates a point of departure (PD). (Figure A-28 on page A-21 depicts direction of attack JOAN.)
A-79. The final coordination line is a phase line close to the enemy position used to coordinate the lifting or shifting of supporting fires with the final deployment of maneuver elements (ADRP 3-90). Final adjustments to supporting fires necessary to reflect the actual versus the planned tactical situation take place before crossing this line. It should be easily recognizable on the ground. The FCL is not a fire support coordination measure. (Figure A-30 shows PL ROBERT as the FCL for the 4th Brigade.)
A-80. The limit of advance is a phase line used to control forward progress of the attack. The attacking unit does not advance any of its elements or assets beyond the limit of advance, but the attacking unit can push its security forces to that limit (ADRP 3-90). A commander usually selects a linear terrain feature, perpendicular to the direction of attack, on the far side of the objective as the limit of advance (LOA) because such a terrain feature is easily identifiable. The commander employs a LOA to prevent overextending the attacking force and reduce the possibility of fratricide and friendly fire incidents by fires supporting the attack. The commander positions a LOA far enough beyond the objective to allow the unit to defend the objective. A LOA prevents units from exploiting success and launching a pursuit; therefore, commanders should only use LOAs if they do not want their units to conduct an exploitation or pursuit. A forward boundary is always a LOA, but a LOA is not necessarily a forward boundary. In fact, a LOA and the unit’s forward boundary should rarely coincide because of the resulting limitations that a forward boundary places on supporting fires beyond the forward boundary. Figure A-30 shows PL BASIL used as 4th Brigade’s LOA.
A-81. The line of departure is a phase line crossed at a prescribed time by troops initiating an offensive operation (ADRP 3-90). The purpose of the LD is to coordinate the advance of the attacking force, so that its elements strike the enemy in the order and at the time desired. The LD also marks where the unit transitions from movement to maneuver. The commander can also use it to facilitate the coordination of fires. Generally, it should be perpendicular to the direction the attacking force will take on its way to the objective. Friendly forces should control the LD. The commander analyzes the terrain before designating a LD. Different units have different movement rates on leaving their AAs based on their inherent mobility characteristics and the terrain being crossed. The commander considers these different characteristics when establishing the LD to prevent these differences from affecting the synchronization of the operation. When possible, the commander selects the LD so that the terrain the attack unit traverses before crossing the LD provides sufficient cover for the attacking unit’s final deployment into a combat formation before crossing the LD. In many cases the LD is also the LC because the unit in contact is conducting the attack from its current positions. Figure A-30 depicts PL JOHN as a combined LD and LC.
A-82. An objective is a location on the ground used to orient operations, phase operations, facilitate changes of direction, and provide for unity of effort (ADRP 3-90). An objective can be either terrain- or
force-oriented. Terrain objectives should be easily identifiable on the ground to facilitate their recognition. The commander determines force-oriented objectives based on known enemy positions. The commander normally assigns subordinate commanders only their final objectives, but can assign intermediate objectives as necessary. Figure A-30 on page A23 depicts objective PAT. Objective PAT is further broken down into two subordinate objectives, objective KAI and objective ZEKE.
A-83. The point of departure is the point where the unit crosses the LD and begins moving along a direction of attack (ADRP 3-90). Units conducting reconnaissance and security patrols and other operations in a low-visibility environment commonly use a PD as a control measure. Like an LD, it marks the point where the unit transitions from movement to maneuver under conditions of limited visibility. Figure A-31 depicts PD 7.
A-84. A probable line of deployment is a phase line that designates the location where the commander intends to deploy the unit into assault formation before beginning the assault (ADRP 3-90). The PLD is used primarily at battalion level and below when the unit does not cross the LD in its assault formation. It is usually a linear terrain feature perpendicular to the direction of attack and recognizable under conditions of limited visibility. The PLD should be located outside the range where the enemy can place the attacking force under effective direct fire. It has no use except as it relates to the enemy. In figure A-30 on page A-23, PL ROBERT could also be designated as the PLD.
A-85. A rally point is an easily identifiable point on the ground at which aircrews and passengers can assemble and reorganize following an incident requiring a forced landing. Alternatively, it is also an easily identifiable point on the ground at which units can reassemble and reorganize if they become dispersed (ADRP 1-02). Forces conducting a patrol or an infiltration commonly use this control measure. The objective rally point is a rally point established on an easily identifiable point on the ground where all elements of the infiltrating unit assemble and prepare to attack the objective (ADRP 3-90). It is typically near the infiltrating unit’s objective; however, there is no standard distance from the objective to the objective rally point. It should be far enough away from the objective so that the enemy will not detect the infiltrating unit’s attack preparations. Figure A-32 depicts rally point 14.
A-86. A support by fire position designates the general position from which a unit conducts the tactical mission task of support by fire (ADRP 3-90). (Appendix B defines the tactical mission task of support by fire.) The purpose of these positions is to increase the supported force’s freedom of maneuver by placing direct fires on an objective that is going to be assaulted by a friendly force. Support by fire positions are located within the maximum friendly direct-fire range of the enemy positions. The commander selects them so that the moving assault force does not mask its supporting fires. For this reason, support by fire positions are normally located on the flank of the assault force,
Figure A-32. Rally point 14
Figure A-33. Support by fire position
elevated above the objective if possible. Support by fire positions are rarely applicable to units larger than company size. The support by fire position graphic depicted in figure A-33 indicates the general location and direction from which the unit provides fires; it does not indicate a specific site.
A-87. The time of attack is the moment the leading elements of the main body cross the line of departure, or in a night attack, the point of departure. (ADRP 3-90). A commander uses it when conducting simultaneous operations where a shaping operation must accomplish its mission to set the conditions for the success of the decisive operation. When determining time of attack, the commander considers the time subordinates require to—
- Conduct necessary reconnaissance, prepare plans, and issue orders.
- Synchronize plans between all subordinate units.
- Complete attack preparations, such as pre-combat inspections.
- Move to the LD or PD.
A-88. Orders normally designate the time of attack as H-hour. This is normally when the main body crosses the LD. However, H-hour can also designate the time to implement a phase of an operation, such as an airborne or air assault phase. The headquarters planning the operation specifies the term’s exact meaning. This is usually a part of the unit’s standard operating procedures (SOPs).
COMMON DEFENSIVE CONTROL MEASURES
A-89. The commander controls the defense by using control measures to provide the flexibility needed to respond to changes in the situation and allow the defending commander to rapidly concentrate combat power at the decisive point. Defensive control measures within a commander’s AO include designating the security area, the battle handover line (BHL), the main battle area (MBA) with its associated FEBA, and the echelon support area. (FM 3-90-2 discusses tactics associated with the conduct of security tasks.) (Paragraph A-104 defines the FEBA.) The commander can use battle positions and additional direct fire control and FSCMs in addition to those control measures discussed earlier in appendix A to further synchronize the employment of combat power. The commander designates disengagement lines to trigger the displacement of subordinate forces. These common defensive control measures are discussed in alphabetical order below.
A-90. A battle position is a defensive location oriented on a likely enemy avenue of approach (ADRP 3-90). The battle position is an intent graphic that depicts the location and general orientation of the majority of the defending forces. A commander’s use of a battle position does not direct the position of the subordinate’s entire force within its bounds since it is not an AO. (See figure A-34.) Units as large as battalion task forces and as small as squads or sections use battle positions. They may occupy the topographical crest of a hill, a forward slope, a reverse slope, or a combination of these areas. The commander selects positions based on terrain, enemy capabilities, and friendly capabilities. A commander can assign all or some
subordinates battle positions within the AO. (See figure A-35 on page A-26.)
A-91. The commander may assign subordinates battle positions in situations when there is a need to retain a greater degree of control over the maneuver of subordinate units than that provided through only using an AO, as the commander controls maneuver outside the general location of the battle position. Multiple battle positions may be assigned to a single unit, which allows that unit to maneuver between battle positions. The commander specifies mission and engagement criteria to the unit assigned to a battle position. Security, functional and multifunctional support, and sustainment forces typically operate outside a unit’s battle position.
A-92. Units occupy or depart battle positions as part of the overall plan. The commander assigning a unit to a battle position should specify when and under what conditions the unit displaces from the position, since they are not normally held at all costs. If a unit is ordered to defend a battle position, its commander has the option of moving off the battle position. If that unit is directed to retain a battle position, its commander needs to know the specific conditions that must exist before the unit can displace.
A-93. There are five kinds of battle positions—primary, alternate, supplementary, subsequent, and strong point. (See figure A-36.) When assigning battle positions, the commander always designates the primary battle position. The commander designates and prepares alternate, supplementary, and subsequent positions as time and other resources permit and if the terrain or situation requires them.
A-94. The primary position is the position that covers the enemy’s most likely avenue of approach into the area of operations (ADRP 3-90). It is the best position from which to accomplish the mission, such as cover an EA.
A-95. An alternate position is a defensive position that the commander assigns to a
Figure A-36. Five kinds of battle positions
unit or weapon for occupation when the primary position becomes untenable or unsuitable for carrying out the assigned task (ADRP 3-90). It covers the same area as the primary position. The commander locates alternate positions so the occupant can continue to fulfill the original task, such as covering the same avenue of approach or EA as the primary position. These positions increase the defender’s survivability by allowing the defender to engage the enemy from multiple positions. For example, a unit moves to its alternate positions when the enemy brings suppressive fires on the primary position.
A-96. A supplementary position is a defensive position located within a unit’s assigned area of operations that provides the best sectors of fire and defensive terrain along an avenue of approach that is not the primary avenue where the enemy is expected to attack (ADRP 3-90). For example, an avenue of approach into a unit’s AO from one of its flanks normally requires establishing supplementary positions to allow a unit or weapon system to engage enemy forces traveling along that avenue.
A-97. A subsequent position is a position that a unit expects to move to during the course of battle (ADRP 3-90). A defending unit may have a series of subsequent positions. Subsequent positions can also have primary, alternate, and supplementary positions associated with them.
A-98. A strong point is a heavily fortified battle position tied to a natural or reinforcing obstacle to create an anchor for the defense or to deny the enemy decisive or key terrain (ADRP 3-90). The commander prepares a strong point for all-around defense. (See figure A-37.) The commander positions strong points on key or decisive terrain. The unit occupying the strong point prepares positions for its weapon systems, vehicles, Soldiers, and supplies. The commander also establishes a strong point when anticipating that enemy actions will isolate a defending force retaining terrain critical to the defense.
A-99. Before assigning a strong point mission, the commander ensures
that the strong point force has sufficient time and resources to construct the position, which requires significant engineer support. A minimally effective strong point typically requires a one-day effort from an engineer unit the same size as the unit defending the strong point. Normally, companies and battalions occupy strong points, although brigades may construct them. The commander does not normally establish strong points for units smaller than company size. This is because a platoon or squad cannot secure a perimeter large enough to encompass all required assets and supplies.
A-100. The commander engages
Figure A-38. Direct fire control measures
the enemy force with all available defensive fires when it enters the defending unit’s engagement area. These direct fire control measures, such as TRPs, trigger lines, and EAs, are discussed in this appendix under the heading of “common offensive control measures” in paragraphs A-27, A-28, and A-23. (See figure A-38.)
A-101. A disengagement line is a phase line located on identifiable terrain that, when crossed by the enemy, signals to defending elements that it is time to displace to their next position (ADRP 3-90). Phase Line JOAN is a disengagement line in figure A-39. The commander uses these lines in the delay and the defense when the commander does not want the defending unit to become decisively engaged. The commander establishes criteria for the disengagement, such as number of enemy vehicles by type, friendly losses, or enemy movement to flanking locations. Commanders may designate multiple disengagement lines, one for each system in the defense.
A-102. The commander tries to engage the enemy at extended ranges and attrit the enemy force as the enemy’s attack advances. To control indirect fires in the defense, the commander uses those common FSCM introduced in paragraphs A-32 through A-45. The commander can also employ final protective fires.
A-103. Final protective fire is an immediately available preplanned barrier of fires designed to impede enemy movement across defensive lines or areas (JP 1-02). Both direct- and indirect- fire weapons can provide FPFs. The commander can only assign each firing battery or platoon a single FPF. A FPF is a priority target for an element or system, and those fire units are laid on that target when they are not engaged in other fire missions. When the enemy force initiates its final assault into a defensive position, the defending unit
initiates its FPFs to kill enemy infantry soldiers and suppress enemy armored vehicles. (Figure A-39 depicts an FPF.)
A-104. The forward edge of the battle area is the foremost limit of a series of areas in which ground combat 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 (JP 3-09.3). The Army only uses a FEBA during the conduct of defensive tasks. The FEBA is not a boundary, but it conveys the commander’s intent. It marks the foremost limits of the areas in which the preponderance of ground combat units deploy, excluding the areas in which security forces are operating.
MBA forces can temporarily move forward of the FEBA to
expedite the retrograde operations of security forces. The commander designates a FEBA to coordinate fire support and to assist in the maneuver of subordinate forces. A phase line designating the forward-most point of the MBA indicates the FEBA. The FEBA shows the senior commander’s planned limit for the effects of direct fires. Defending units must address this area in their scheme of maneuver and exchange information regarding tactical plans at coordination points. (Figure A-40 graphically depicts the current FEBA and a proposed FEBA.)
A-105. The main battle area is the area where the commander intends to deploy the bulk of the unit’s combat power and conduct decisive operations to defeat an attacking enemy (ADRP 3-90). The defending commander’s major advantage is the ability to select the ground on which the battle takes place. The defender positions subordinate forces in mutually supporting positions in depth to absorb enemy penetrations or canalize them into prepared EAs, defeating the enemy’s attack by concentrating the effects of overwhelming combat power. The natural defensive strength of the position determines the distribution
of forces in relation to both frontage and depth. In addition, defending units typically employ field fortifications and obstacles to improve the terrain’s natural defensive strength. The MBA also includes the area where the defending force creates an opportunity to deliver a decisive counterattack to defeat or destroy the enemy.
A-106. The MBA extends from the FEBA to the unit’s rear boundary. The commander locates subordinate unit boundaries along identifiable terrain features and extends them out beyond the FLOT by establishing forward boundaries. Unit boundaries should not split avenues of approach or key terrain. The commander selects the MBA based on the products of the IPB process and the commander’s own analysis using the mission variables of METT-TC. The IPB process indicates how the enemy force will probably use the available avenues of approach.