Radio Communication Failure

Radio failure procedures including squawk 7600 setting

Radio communication failure occurs when a pilot loses the ability to communicate with air traffic control (ATC) via radio. In such cases, the standard transponder code 7600 is used to indicate the issue.

What it means

When an aircraft experiences a radio communication failure, it means the pilot can no longer transmit or receive voice communications with ATC.

How pilots indicate it

To alert ATC, pilots set their transponder to the emergency code 7600.

ATC response

ATC may attempt to reach the aircraft on the guard frequency (121.5 MHz in the US), or via alternate methods.

Other communication methods

Airlines may use ACARS and Controller Pilot Data Link Communications (CPDLC) for data link communications when voice radio is unavailable.

Causes

Common causes include:

• Radio equipment failure
• Electrical issues
• Improper frequency selection
• Environmental interference

Procedures

If a radio failure occurs:

• Under VMC, continue under visual flight rules and land at the nearest suitable airport.
• Under IMC, continue based on last ATC clearance and standard procedures.

References

• FAA Air Traffic Publications
• Skybrary - Radio Communication Failure