What is a Secondary Target Line (STL)?

• A. A backup radar feed for early warning.
• B. A preplanned alternative target line used to shift the orientation of fires.
• C. A line of fires used to divert enemy air attacks.
• D. A contingency plan for switching to manual control.

Answer: (B)

A Secondary Target Line is a preplanned alternate line of fire used to shift the orientation of fires. It lets you rapidly redirect engagements to a different axis or target group without rewriting your plan in the heat of battle, keeping the firing sequence and coordination intact while you reallocate fire to where it’s needed most. It’s prepared in advance as part of the engagement plan so you can move to it quickly if the target moves, terrain, or priority changes require a different fire direction. It’s not a radar feed for early warning, not a dedicated line to divert air attacks, and not a manual-control contingency; it’s a ready-to-use alternative line of fire to maintain effective coverage.