How many mils apart are the radial arms of an OF fan?

The correct answer is based on the standard measurements used in fire support operations. The radial arms of an Obstacle Free (OF) fan are designed to be 100 mils apart. This specific measurement allows for effective dispersion and ensures that the fire support encompasses an adequate area while maintaining clarity in communication and coordination.

Understanding the configuration of the OF fan is crucial for FIST personnel, as it affects target identification, weapon placement, and the coordination of indirect fire. The radial arms represent lines along which the observer can spread fire effects, ensuring proper coverage of the target area while also managing safety and effectiveness during operations. By adhering to the 100 mil spacing, the fire support team can make informed decisions about fire placement and engagement strategies.