FM-3-09 Fire Support and Field Artillery Operations Download
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Fire Support in Depth During Large-Scale Ground Combat Operations 30 April 2020 FM 3-09 6-13 Planning for Retrograde Operations 6-57. A defensive situation may require the HQ staff to plan for retrograde operations in combination, sequentially, or subsequent to the defensive mission. Planning and rehearsing a rearward passage of lines of security forces forward of the MBA is critical to ensuring proper execution while under enemy pressure. The complexity and fluidity of retrograde operations and the need to synchronize the entire operation dictate the need for detailed, centralized planning and coordination with decentralized execution. A retrograde may be forced or voluntary. In either event, a higher echelon commander must approve it. FIRE SUPPORT CONSIDERATIONS FOR SUSTAINMENT IN DEFENSIVE OPERATIONS 6-58. Sustained combat in defensive operations will normally generate the largest requirement for supplies and services, stress resupply capabilities for fuel and ammunition, and require rapid evacuation of wounded and equipment repair as far forward as possible. Sustainment for artillery units in a defensive role requires prepositioning of ammunition and other essential supplies. During a delay operation, supplies should be prepositioned at subsequent delay lines or positions. Petroleum, oil, lubricants and ammunition stocks must also be adequate to support decisive defensive actions. 6-59. As operations shift towards the defense, FS sustainment elements should begin to minimize the amount of support forward in the defense. Sustainment staffs will be primarily concerned with providing needed support to firing units engaged in corps-level operations and to divisions in whose area the main enemy effort is expected. 6-60. FS and sustainment planners in the defense should consider ammunition and fuel availability while maximizing organic haul capability and minimizing requirements for resupply. They should preposition additional ammunition and fuel in planned and coordinated cache sites in convenient locations along anticipated routes of withdrawal while making plans to destroy these stocks, if necessary. THE RESERVE IN DEFENSIVE OPERATIONS 6-61. The defense plan retains a reserve regardless of the defensive operation assigned. The reserve is that portion of a body of troops that is withheld from action at the beginning of an engagement to be available for a decisive movement (ADP 3-90). The reserve is more difficult to resource in the mobile defense because so much of the available combat power is allocated to the striking force. 6-62. FS tasks for the reserve are as follows: Plan fires to support the commitment of the reserve during movement. Plan fires to strike at objectives in depth as enemy dispositions are revealed. This is to support the committed reserves and to break up the enemy's coordination of the attack in the area defense. Plan fires on the enemy's flanks and rear where counterattacking forces are committed in the mobile defense. Plan fires to deceive the enemy into thinking the reserve is committed elsewhere. Plan for FSCMs such as an RFL in case of converging forces in the mobile defense or a RFA to safeguard strongpoints in the area defense. Plan to rearm, refit, and refuel organic and supporting fire support before assuming on-order missions. 6-63. As in the offense, a support relationship of GS or GSR is best for artillery units designated to support reserves once committed. Once the reserve is committed, organic FA is augmented by other lethal and nonlethal attack/delivery platforms. Unnecessary changes in organization and time-consuming movements should be avoided to ensure adequate support for the committed reserve. TRANSITION TO THE OFFENSE 6-64. A defending commander seeks a window of opportunity to transition to offensive operations by anticipating when and where an enemy force will reach its culminating point or require an operational pause before it can continue. During these windows, the combat power ratios mostly favor a defending force. An enemy force will do everything it can to keep a friendly force from knowing when it is overextended.