FM-3-09 Fire Support and Field Artillery Operations Download
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Appendix D D-4 FM 3-09 30 April 2020 is protected from indirect fires. For mortars and high-angle artillery fires, the dead space is about one-half the height of the building. For low-angle artillery fires, the dead space is about five times the height of the building behind which the target sits. LETHAL FIRE SUPPORT IN URBAN AREAS D-21. The physical aspects of the urban environment, such as the height and concentration of buildings, cause significant masking and dead space. Buildings that stand three or more stories tall hinder close indirect fires. Tall buildings can potentially mask several blocks of area along the gun-target line of artillery firing at low angles of elevation. The urban environment also affects the type and number of indirect fire weapon systems employed. Commanders may prefer high-angle fire because of its ability to fire in close proximity to friendly occupied buildings. More artillery systems may need to be used to ensure the responsiveness (rather than the weight) of fires. Careful positioning of artillery and mortar systems reduces the amount of dead space and permits units to establish more direct sensor-to-shooter links. D-22. Commanders may consider R units, to include mortar platoons, from units in reserve. This will increase the number of systems available to support maneuver units. MLRS dual purpose improved conventional munitions rockets may be of limited use in urban areas due to their dud rate. GMLRS unitary rockets are well suited for this environment due to their precision munition capabilities and low collateral damage. Requirements for high-angle fire necessitated by confined urban terrain and an increase in point targets make the vertical attack capability option afforded by Excalibur and GMLRS unitary rockets especially useful. D-23. Structures affect Army aviation attacks where the enemy is in contact with friendly ground forces. Vertical structures interrupt line of sight and create corridors of visibility along street axes. The result is shortened acquisition and arming ranges for supporting fires from attack helicopters that affect engagement techniques and delivery options. Pilots maintain line of sight long enough to acquire targets, achieve weapons delivery solutions, and fly to those parameters. Tube-launched, optically tracked, wire-guided heavy antitank missile systems require 65 meters to arm. The Hellfire missile requires at least 500 meters to reliably arm and stabilize on the intended target. Thus, attack helicopters firing from longer ranges actually improve the probability of a hit. Heavy smoke and dust rising from urban fires and explosions may hinder target identification, laser designation, and guidance for rotary- and fixed-winged aircraft. The close proximity of friendly units and noncombatants requires units to agree on, disseminate, and thoroughly rehearse clear techniques and procedures for marking target and friendly locations. AMMUNITION AND SUSTAINMENT D-24. In the absence of attack helicopters, close air support, and related fire support assets, ammunition expenditure is likely to be high. Moving large convoys through rubbled urban terrain and along narrow city streets can affect the sustainment effort. The FA may need to rely on several smaller sustainment convoys. Increased time is allowed for in the planning of logistics activities. Pre-stocked supplies, locally available supplies, and infrastructure services for power and transportation should be used as much as possible. Use local water supplies once they have been certified. Security and the risks of sabotage must be considered in the use of all locally procured items. D-25. Precision fire provided by Army aviation attack or appropriate joint fires may be employed to engage observable targets and minimize collateral damage. Remote designators need to be close enough to accurately designate, but far enough away not to be acquired by the laser-guided munition during its flight path. Consider using precision-guided munitions to defeat enemy forces in buildings or in fortified positions and to target small enemy positions, such as snipers or crew-served weapons. D-26. Considerations for the use of laser designators in urban terrain include: Correct positioning of aerial attack-by-fire positions and observation posts that meet any applicable angle-T requirements. Focus on key buildings, avenues of approach, complexes, or terrain where use of precision-guided munitions is anticipated. Intervening tall structures may degrade the effectiveness of the laser designator. Maintaining a continuous laser track on moving targets is difficult.