ATC light signals have the meaning shown in the following table:
| Color and type of signal | Meaning with respect to aircraft on the surface | Meaning with respect to aircraft in flight |
|---|---|---|
| Steady green | Cleared for takeoff | Cleared to land. |
| Flashing green | Cleared to taxi | Return for landing (to be followed by steady green at proper time). |
| Steady red | Stop | Give way to other aircraft and continue circling. |
| Flashing red | Taxi clear of 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. |