ATC Signals
The chart below provides a general overview of the standard Air Traffic Control (ATC) signal light indications used for aircraft and ground vehicles. These visual signals are part of established ATC tower operating procedures and are intended for use when radio communication is unavailable.
Why This Matters
Light gun signals are a backup communication method mandated by aviation authorities (such as the FAA and ICAO). Familiarity with these standardized signals is an essential part of safe airport operations.
Air Traffic Control Signal Light Reference Chart
| Signal | Aircraft on Ground | Aircraft in Flight | Vehicles/Pedestrians |
|---|---|---|---|
| Steady Green | Cleared for takeoff | Cleared to land | Cleared to cross/proceed/go |
| Flashing Green | Cleared to taxi | Return for landing (followed by steady green) | — |
| Steady Red | Stop | Give way to other aircraft and continue circling | Stop |
| Flashing Red | Taxi clear of landing area or runway in use | Airport unsafe, do not land | Clear the taxiway/runway |
| Flashing White | Return to starting point on airport | — | Return to starting point on airport |
| Alternating Red/Green | Exercise extreme caution | Exercise extreme caution | Exercise extreme caution |