Radio Failure in Flight: The Lost-Comms Playbook

A dead radio is a known problem with a known playbook — not an emergency to panic over. Here is the troubleshooting flow, the squawk code, and the light-gun signals. · 6 min read

A radio failure sounds scary the first time you imagine it, but it is genuinely one of the more manageable abnormal situations in flying — because it has a clear, standard playbook, and because you still have a perfectly good airplane. Pilots have landed at towered airports without a working radio for as long as there have been towers; there is an entire system of light signals built for exactly this. The only real danger in a comm failure is letting it rattle you into flying poorly. So the first rule, as always, is aviate first: keep flying the airplane, then calmly work the problem.

First, check the obvious

Most "radio failures" are not the radio at all — they are a knob, a plug, or a stuck switch. Before you assume the worst, run the quick checks:

Volume turned up? Squelch set correctly? You may just not be hearing anyone.
Are you on the right frequency? An easy one to get wrong when heads-down.
Headset plugged in fully? Mic jack seated? A partially-pulled plug is a classic.
Is the push-to-talk stuck? A stuck PTT transmits constantly and blocks you from hearing — try the yoke switch and the hand mic separately.
Try the other comm radio, or a handheld transceiver if you carry one (many pilots do, exactly for this).

Squawk 7600

If it really is dead, set your transponder to 7600 — the discrete code for lost communications. On radar, 7600 flags you to every controller as a comm-failure aircraft, so they know why you are not answering and can watch for you, clear traffic, and use light signals if you are inbound to a towered field.

What to do next (VFR)

For a VFR pilot, the plan is straightforward: stay VFR, navigate to an airport (often your departure field or a nearby non-towered one where no clearance is needed), and land. If you go to a towered field, overfly or approach where the tower can see you, watch for light-gun signals, and rock your wings to acknowledge that you have received a signal (during the day). At a non-towered field, just fly a normal, extra-careful pattern and land — no radio is legally required there anyway.

Light-gun signals

A towered airport can direct you with a colored light gun. These are worth memorizing — they are on the checkride, and they are the actual tool that gets you home with a dead radio:

Steady green — cleared to land (airborne) / cleared for takeoff (on the ground)
Steady red — give way and keep circling (airborne) / stop (on the ground)
Flashing green — return to land, you will get a steady green next (airborne) / cleared to taxi (ground)
Flashing red — airport unsafe, do not land (airborne) / taxi clear of the runway (ground)
Flashing white (ground only) — return to your starting point on the airport
Alternating red and green — general warning, exercise extreme caution

💡 Fly the airplane first, then work the problem, then land. A comm failure is not a flying emergency — nothing about the airplane has changed. Carrying a cheap handheld transceiver turns this whole scenario into a non-event.

💡 The only way this becomes automatic is saying it out loud, dozens of times, before you key a live mic. That is exactly what ATCpal is for — review the lost-comms flow so it is calm and automatic if it ever happens. Practice it free at atcpal.app.

Phraseology sourced from the FAA Aeronautical Information Manual (Change 3, effective 9 July 2026) and the Pilot/Controller Glossary. Check the AIM · Last reviewed 13 August 2026.

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