What are the four identification friend or foe (IFF) modes?

The identification friend or foe (IFF) system is a critical component in military operations for distinguishing between friendly and enemy forces, enabling safe and effective air defense operations. The IFF modes serve varying functions regarding the identification process.

The four established IFF modes are 1, 2, 3, and 4. Mode 1 is used for basic identification and is most commonly utilized in military applications. Mode 2 is specifically assigned for military aircraft identification. Mode 3 is used for general air traffic control and requires a specific transponder code for air traffic management, which often involves civil airspace as well. Mode 4 indicates secure military identification and is used to distinguish friendly forces from others using an encrypted response signal.

The answer provided aligns correctly with the named IFF modes, confirming a solid understanding of the system's operational capabilities and functions.