How should S-390 results be used to determine a safe location for firing operations or line construction?

• A. Use predicted fire behavior to place control lines and anchor points away from the head fire and select escape routes; maintain safety buffers
• B. Place lines inside the head fire to intercept it
• C. Ignore S-390 results and proceed
• D. Move workers without safety planning

Answer: (A)

Using predicted fire behavior to guide where you place control lines and anchor points, and to select escape routes with safety buffers, is the safest approach. S-390 results tell you how the fire is likely to move given the wind, slope, fuels, and weather, so you position lines ahead of the advancing head and keep a clear margin between the flame front and your work. This gives crews time to establish containment and provides safe egress if conditions shift, reducing exposure to extreme heat and erratic fire behavior. Placing lines inside the head fire puts crews directly in the most intense part of the fire and is highly dangerous. Proceeding without relying on fire-behavior predictions or without a safety plan neglects essential risk assessment, and moving workers without a deliberate plan increases the likelihood of harm.