Which code indicates communication and navigation failure combined if comm lost?

Which code indicates communication and navigation failure combined if comm lost?

• A. 7600
• B. 7500
• C. 7700
• D. 7605

Answer: (A)

When you lose radio communication, you use the transponder code 7600. This code tells ATC that you have a communications failure and you will continue with your last assigned clearance while trying to re-establish contact. It’s the standard signal for loss of communication, regardless of whether navigation equipment is also affected. The other options serve different purposes: 7500 is for hijack, 7700 is for general emergency. The code 7605 is not part of the universally used set for standard comm/nav status, so it’s not the correct choice here.

When you lose radio communication, you use the transponder code 7600. This code tells ATC that you have a communications failure and you will continue with your last assigned clearance while trying to re-establish contact. It’s the standard signal for loss of communication, regardless of whether navigation equipment is also affected.

The other options serve different purposes: 7500 is for hijack, 7700 is for general emergency. The code 7605 is not part of the universally used set for standard comm/nav status, so it’s not the correct choice here.