What are lines established relative to the fire support coordination line (FSCL) for guidance in the use of IFF/SIF interrogation by friendly air defenses?

• A. IFF On
• B. IFF Off
• C. IFF On / IFF Off
• D. PID On

Answer: (C)

Understanding how air defenses identify friendly aircraft near the fire support coordination line is essential to prevent fratricide while keeping fire support coordinated. The guidance uses two lines relative to the FSCL that tell friendly air defenses when to use IFF/SIF interrogation. One line requires IFF interrogation to be active (On) inside or near the FSCL so targets can be positively identified before engagement. The other line requires IFF interrogation to be not used (Off) outside that area to avoid unnecessary interrogations or misidentifications that could disrupt fire support. Together, IFF On / IFF Off gives clear, location-based guidance for when to interrogate, which is why this option is correct. PID On is a related concept in identification but does not describe the specific boundary guidance for IFF/SIF interrogation relative to the FSCL.