When can routine communications be resumed when radio silence has been imposed?

Correct Answer: Option C — Routine communications can resume after the Rescue Coordination Center transmits a message on the frequency or channel being used for emergency communications stating that such traffic has concluded.

The authority to terminate radio silence rests with the Rescue Coordination Center (RCC) or the On-Scene Coordinator (OSC) managing the distress traffic. Routine communications may only resume once an official announcement is made on the frequency, signaling that the emergency phase has concluded and the channel is clear.