ATP-3-09-30 Observed Fires Download
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Special Munitions 28 September 2017 ATP 3-09.30 6-25 Table 6-17. Equivalent wind scale for estimating wind speed Knots Observation 1 Smoke, vapor from breath, or dust raised by vehicles or personnel rises vertically. There is no leaf movement. 1 to 3 Direction of wind slightly shown by smoke, vapor from breath, or dust raised by vehicles or personnel. There is slight intermittent movement of leaves. 4 to 6 Wind is slightly felt on face. Leaves rustle. 7 to 10 Leaves and twigs are in constant motion. 11 to 16 Wind raises dust from ground. Loose paper and small branches move. 17 to 21 Small trees with leaves sway. Coastal wavelets form on inland waters. 22 to 27 Large branches on trees are in motion. A whistle or hum is heard in telephone or fence wires. 28 to 33 Whole trees are in motion. Inconvenience is felt when walking against the wind. Note. One knot equals 1.15 miles per hour Wind Direction 6-105. Wind direction influences the desired location of smoke in the target area. To determine wind direction in the target area, observe drifting of smoke or dust, bending of grass or trees, and ripples on water. See figure 6-14 for classification of wind directions. Figure 6-14. Classification of wind directions Maneuver-Target Line 6-106. Determine the wind direction (right or left cross, tail, or head) in relation to the maneuver-target line (MTL) (see figure 6-15 on page 6-26). The MTL is an imaginary line drawn from the maneuver unit’s most vulnerable point along its route of march to the threat unit’s observation point.