Which IFF modes are military?

• A. 1,2,3
• B. 0,3,5
• C. 2,4,6
• D. 1,4,5

Answer: (A)

IFF modes are the ways a radar system and a responder identify friend or foe, with certain modes reserved for military use. The three modes in question are the classic military identifiers used historically to recognize aircraft in operations. Mode 1 carries a mission-specific code that helps track a particular operation or target, making it useful for mission planning and coordination. Mode 2 provides a unit- or aircraft-specific code that supports recognition within a formation or unit. Mode 3 serves as a basic identity code used in military contexts to confirm who is replying when interrogated.

The other options mix in modes that are civilian or newer secure implementations. For example, encryption-focused modes (like Mode 4 and Mode 5) are designed to prevent spoofing and are used in modern secure military IFF, while civilian air traffic control relies on different civilian-mode identifiers. Given the traditional military identification framework described, the set that matches military IFF modes is 1, 2, and 3.