ATP-3-09-30 Observed Fires Download

Chapter 6 6-14 ATP 3-09.30 28 September 2017  "Wash out" threat passive night sight systems when used at ground level. EMPLOYMENT CONSIDERATIONS 6-59. Illumination rounds may aid target acquisition when friendly forces are using image intensification devices (such as night vision devices), but can create problems when thermal sights are used. As the illumination flares burn out and land on the ground, they remain as a distinct hot spot seen through thermal sights for several minutes. This may cause confusion and make acquiring targets more difficult, especially when the flares are between the threat and the friendly forces. 6-60. The amount of illumination required for a particular mission depends on the observer-target distance; the conditions of visibility; and the size, width, and depth of the area to be illuminated. By selecting the proper illuminating pattern and controlling the rate of fire, the observer can light an area effectively with a minimum expenditure of ammunition. See table 6-13 for the rates of fire for continuous illumination and other information on the employment of illuminating shells. Table 6-13. Employment factors for illuminating shells Howitzer or Mortar Projectile Initial Height of Burst (meters) Distance Between Bursts (Spread) (meters) Burning Time (seconds) Rate of Continuous Illumination (rounds per minute) Rate of Descent (meters per second) 155-mm M485A2 600 1000 120 1 5 155-mm M1066 (IR) 700 1500 120 1 10 120-mm M 930 500 890 50 to 60 2 8-10 120-mm M930E1 500 890 50 to 60 2 8-10 120-mm M91 890 46 to 60 2 8-10 120-mm M 983 (IR) 500 1219 50 to 60 2 8-10 105-mm M314A2 750 800 60 2 10 105-mm M314A3 750 800 60 2 10 105-mm M1064 (IR) 750 800 60 2 10 81-mm M301A3 600 450 60 2 6 81-mm M853A1 475 624 50 2 8-10 81-mm M816 (IR) 475 855 50 2 8-10 60-mm M721 425 460 40 2 8 60-mm M767 (IR) 425 630 55 2 8 60-mm M83A3 1 160 250 30 4 6 Note. 1 The 60-mm illuminating round M83A3 firing one round will provide moderate light over a square kilometer. The small size and limited burn time of the 60-mm illuminating round makes it more suitable for point illumination than for area illumination. The 60-mm illuminating round normally can be used without degrading night vision devices of adjacent units. Legend. IR—infrared mm—millimeters ONE GUN ILLUMINATION 6-61. Use the one gun illumination pattern when effective illumination can be accomplished by firing one round at a time. To obtain this pattern, the observer calls for ILLUMINATION as the type of adjustment and type of projectile.