Light gun signals: what every color means
What the tower's light gun means when your radio fails, on the ground and in the air.
If your radio fails near a towered airport, the tower can still talk to you with a light gun: a bright, narrow beam of green, red or white light aimed at your airplane. What a signal means depends on whether you are on the ground or in the air, so the same color can mean two different things.
The light gun signal chart
| Signal | On the ground | In the air |
|---|---|---|
| Steady green | Cleared for takeoff | Cleared to land |
| Flashing green | Cleared to taxi | Return for landing (wait for a steady green to land) |
| Steady red | Stop | Give way to other aircraft and continue circling |
| Flashing red | Taxi clear of the runway in use | Airport unsafe, do not land |
| Flashing white | Return to starting point on airport | Not applicable |
| Alternating red and green | Exercise extreme caution | Exercise extreme caution |
Source: FAA AIM 4-3-13, Table 4-3-1.
How to acknowledge a light signal
- Daytime, in the air: rock your wings.
- Daytime, on the ground: move your ailerons or rudder.
- At night: flash your landing light or navigation lights.
Lost communications: what to do first
Set your transponder to 7600, keep flying the airplane, and stay outside the airport's airspace until you can see which way traffic is flowing. Watch the tower for a light signal, and follow the lost-communication procedure your instructor taught you. Practice the calls in the Radio Trainer.
A memory trick that actually works
Green means go, red means don't, and flashing means "do the next step": flashing green on the ground is the step before takeoff (taxi), and in the air it is the step before landing (come back). Flashing red is the "get out" signal: off the runway on the ground, away from the airport in the air.
Radio Trainer
Practice lost-comm and tower calls out loud
Open →Flashcards
Light gun signals deck with spaced repetition
Open →Common questions
Does a steady green mean the same thing on the ground and in the air?
No. On the ground a steady green means cleared for takeoff. In the air it means cleared to land.
What does a flashing white light gun signal mean?
On the ground it means return to your starting point on the airport. It has no meaning for aircraft in flight.
What transponder code do I use for lost communications?
Squawk 7600, then follow your lost-communication procedure and watch the tower for light signals.
Sources, review & change history
- Published
- Oct 26, 2026
- Review status
- Written from the FAA sources linked in the text. Not yet re-checked line by line or reviewed by a flight instructor.
- Changes
- Oct 26, 2026: first published.
Study aid only. Your instructor, current 14 CFR and the FAA's handbooks and ACS have the final word.