What action is required if a pilot experiences a radio failure?

In the event of a radio failure, the appropriate action for a pilot to take is to change to a transponder code of 7600. This transponder code is specifically designated for situations involving radio communication failure. When a pilot sets their transponder to 7600, air traffic control (ATC) is immediately alerted to the fact that the aircraft is experiencing a communication issue. This allows ATC to take necessary precautions and provide assistance to the aircraft, such as giving clear visual cues or instructions for landing or routing.

The other options can lead to confusion during a radio failure situation. Switching to the nearest frequency without the means to communicate can be ineffective. Requesting immediate landing clearance when unable to communicate may not relay the urgency of the situation to ATC. While informing ATC is important, it must be done when communication is available, making the transponder code of 7600 the critical and immediate response to signal the failure of radio communication.