It might be a radio failure, but first...

1) Volume And Squelch

Try to adjust the volume and squelch. It's possible your volume was turned down too far, or the squelch isn't sensitive enough.

2) Switch Radios

If your aircraft has more than one radio, try transmitting on the other radio.

3) Verify/Change Frequencies

Verify that you have the correct frequency dialed in! If the frequency is correct, try to locate an alternate frequency for the same station you are trying to contact. The frequency you are on may not be monitored at the moment, or the ground-based antenna might have an issue.

4) Handheld Microphone

If you can hear ATC but they aren't able to hear you, try using the handheld microphone. The push-to-talk button may not be working, or the COM1/COM2 radios may not be transmitting properly at all.

5) Use Your Cellphone

If nothing else is working, use your cellphone and call tower or a FSS. Let them know you've had a radio failure, and either ATC will clear you in as usual or FSS will coordinate with ATC to get you safely back on the ground.

6) Squawk 7600

By squawking 7600 (lost communications squawk code), ATC will know you've had a communications failure.

7) Circle

If you start squawking 7600 near a tower controlled airfield, start circling outside the airspace and wait for light gun signals from ATC.

8) Divert

Worst case scenario, divert to a non-towered airport. Begin by flying over the field at 1,000' above the published traffic pattern altitude. By doing this, you're able to determine the best suitable runway for landing, view the runway conditions, and of course, to locate any traffic that may be in the pattern or on the airport surface. Then, enter the traffic pattern and land.

Have you ever had a radio failure? Tell us about it in the comments below.