In aviation, Radio Silence is a procedure adopted during aircraft emergencies to ensure that the frequency in use is made exclusively available to the aircraft in distress, for better service and effective communication.
Radio Silence aims to achieve:
✅ Effective exchange of information: Pilots can give more detailed description of the emergency situation, and controllers can easily provide more useful information.
✅ Effective navigational assistance: Providing effective navigational assistance during emergencies requires dedicated communication.
✅ Reduced distraction: Radio silence ensures unnecessary distractions are avoided so the air traffic controllers and flight crew in distress can focus properly on resolving the emergency.
METHODS OF IMPOSING RADIO SILENCE
There are mainly two methods of imposing/ensuring radio silence, which are:
Suppressing Calls – Air Traffic Controllers can suppress calls from other aircrafts on the frequency. Example: “All stations [ATS unit] stop transmitting. Mayday!” Or, only calls from a particular aircraft which is interfering may be suppressed. Example: “[Aircraft Call Sign] [ATS Unit] stop transmitting. Mayday!” An aircraft requested to maintain radio silence will do so until advised that the emergency situation has been resolved.
Transferring Communication – Alternatively, communication with other aircrafts may be transferred to another frequency (or frequencies). Example: “Mayday, [Call Sign of the aircraft in distress], remain on this frequency. All other aircrafts contact [appropriate ATS Unit] [frequency].” However, due to high stress levels and the risk of communication errors, transferring distress traffic is considered inappropriate.
Please note that the decision to impose radio silence and the chosen method depends on specific circumstances and the judgment of the Controllers involved.
REFERENCES
ICAO Doc 9432
