What lights up for IFF lost comms?

What lights up for IFF lost comms?

• A. 7600
• B. 7601
• C. 7602
• D. 7603

Answer: (A)

When radio communications are lost, the aircraft should set its transponder to a specific code that signals this condition to ATC. That code is 7600. Entering 7600 makes the radar blip and the transponder display indicate a lost-communications situation, so controllers know you cannot communicate and can adjust their instructions accordingly. The other codes—7601, 7602, 7603—are not the standard indications for lost comms and aren’t used to convey the general radio-failure situation. For reference, 7500 is hijack and 7700 is emergency, which are distinct scenarios.

When radio communications are lost, the aircraft should set its transponder to a specific code that signals this condition to ATC. That code is 7600. Entering 7600 makes the radar blip and the transponder display indicate a lost-communications situation, so controllers know you cannot communicate and can adjust their instructions accordingly. The other codes—7601, 7602, 7603—are not the standard indications for lost comms and aren’t used to convey the general radio-failure situation. For reference, 7500 is hijack and 7700 is emergency, which are distinct scenarios.