FM-3-09 Fire Support and Field Artillery Operations Download
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Appendix D D-10 FM 3-09 30 April 2020 HE-point detonating is very effective because it produces extra fragmentation from splintering rocks. Variable time and time fuzes are very effective because the burst covers a larger area than HE-point detonating on reverse slopes. FA mines are effective to deny the enemy the use of narrow defiles, valleys, roads, and usable terrain. When smoke and illumination are used: Swirling winds make smoke employment very difficult to adjust and maintain. Close coordination is required with adjacent elements to ensure they are not obscured or that they are not highlighted. Mortars are ideal for targets on reverse slopes and over intermediate crests because of their high-angle fires. Airbursts on reverse slopes are extremely effective. TARGET ACQUISITION AND OBSERVATION D-59. The following are considerations when FOs are involved in mountain operations: The observers should be positioned on high ground and spread out to overcome terrain masks and compartments. The observers may need mountaineering equipment to get to the best positions, or they may be airlifted. Terrain sketches and visibility diagrams are useful to deliver fast, accurate fires and to identify blind spots. Heavy fogs or low clouds may obscure observation. Observers (without laser rangefinders) who are looking up tend to underestimate range, whereas observers looking down tend to overestimate range. D-60. Air observers: Are very effective to observe beyond terrain masks, in deep defilade, and on reverse slopes. Complement the FIST observers. Can be used to detect deep targets May be confined to valleys and lower elevations because thin air at high elevations makes flying difficult. D-61. Radar considerations in mountain operations include: Radars should concentrate on terrain that can be occupied by artillery and mortars (as determined by IPB). Terrain masks can degrade the effective range of the radar. Additional use of ground surveillance radars and remote sensors may be required. More extensive use of shelling reports may be required. TARGETING D-62. The intelligence officer's IPB should identify the following: Routes that can be used by the enemy to attack, withdraw, and resupply. Likely position areas for enemy indirect fire assets, command and control elements, support assets, and observation posts. Terrain that is subject to snows slides, rockslides, or avalanches. These may deny the enemy use of roads and trails and may destroy elements in defilade.