2.16 Loss of Communications - Aircraft Equipment

2.16.2 Describe the checks that should be followed when becoming aware of an aircraft communication system failure, including a check of:

If a communication problem is suspected, the pilot should first determine whether the issue is with the aircraft equipment, the selected settings, or the microphone/headset system.

These checks should be carried out promptly while maintaining aircraft control, lookout, and terrain clearance.

(a) radio power source;

Check that the radio has electrical power available.

Confirm that:

• Master switch is on
• Avionics switch is on
• Circuit breakers or fuses have not popped or blown
• Radio display is active and showing the selected frequency

A loss of electrical supply, tripped circuit breaker, or switched-off avionics master may make the radio appear unserviceable when the equipment itself is not faulty.

(b) function settings (frequency, squelch and similar);

Check that the radio and audio panel are correctly set up.

Confirm that:

• The correct frequency is selected
• The squelch function and level are set correctly
• The volume is not turned down too low
• The correct COM radio or communications box is selected
• The correct transmit/receive selector is being used, if fitted
• The frequency is within range for the station being called