FM-3-09 Fire Support and Field Artillery Operations Download
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Fire Support Coordination Measures 30 April 2020 FM 3-09 B-15 Figure B-13. Phase line and trigger line example B-46. The commander can establish another trigger line for the 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 the direct fire systems from engaging the enemy. The commander establishes other trigger lines 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. This could result in losing the effect that the sudden application of massed fires has on an enemy. B-47. When the enemy reaches these closer trigger lines, the commander establishes a decision point to help determine should longer-range systems continue to fire in depth or to concentrate fires on a single point. Many factors impact the decision, most of which concern the enemy and how they maneuver and the effects of the defending force's fires. B-48. The purpose of each phase line and any actions required by forces affected by the phase line will be specified on the OPORD of the establishing HQ. Any commander given an AO can establish a phase line. For more on phase lines see ADP 3-90. POSITION AREA FOR ARTILLERY B-49. 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 (FM 3-90-1) (see figure B-14 on page B-16). The maneuver commander assigns PAA as a terrain management technique. A PAA potentially attracts enemy counterfire so other units should stay away from that area to avoid enemy artillery attacks. The exact size of a PAA depends on the mission variables of mission, enemy, terrain and weather, troops and support available, time available, and civil considerations (referred to as METT-TC). A Paladin platoon normally requires a PAA encompassing over four square kilometers, and a MLRS platoon requires twelve square kilometers. Units equipped with M119A3 or M777A2 requires one square kilometer PAA.