Loss of Communication Procedures

Recognising and Troubleshooting Communication Failure

When communication is lost, pilots should first systematically troubleshoot the issue. Check frequency selection, radio volume, headset connections, and audio panel settings. Try contacting ATC on previous or alternative frequencies, including 121.5 MHz, and use a second radio if available. Only after all checks and attempts fail should the situation be treated as a true radio failure.

Standard Radio Failure Procedures

• Set the transponder to code 7600 to indicate radio failure.
• If able, continue in Visual Meteorological Conditions (VMC) and land at the nearest suitable airfield outside controlled airspace.
• In controlled airspace or IMC, follow published procedures: maintain the last assigned level and speed for seven minutes after setting 7600, then proceed in accordance with the current flight plan.
• Avoid entering controlled airspace or Radio Mandatory Zones (RMZ) without clearance unless safety requires it.
• Make "blind transmissions"—broadcast your intentions and position on the assigned frequency, stating "TRANSMITTING BLIND" or "TRANSMITTING BLIND DUE TO RECEIVER FAILURE."

Additional Actions and Considerations

• Assess fuel, daylight, weather, and whether the failure is isolated or part of a larger electrical issue.
• When receiver failure is suspected, transmit position reports at scheduled times or reporting points, prefacing with "TRANSMITTING BLIND DUE TO RECEIVER FAILURE."
• Exercise extra vigilance for other traffic, especially when arriving at airfields that may not expect you.

Distress and Blocked Frequency Procedures

• Distress messages (MAYDAY) take absolute priority; all other stations must maintain radio silence unless assisting.
• If a frequency is blocked, it can compromise safety and delay critical communication, so always listen before transmitting and avoid unnecessary transmissions.