Light-gun signals
Tower may direct aircraft with a coloured light gun if radio is lost. Stay continuously alert for visual signals (TC AIM RAC 4.4.5). Comply with CAR-prescribed light signals and ground markings at all times, provided safety is not jeopardized (PSTAR 6.21).
Meaning depends on colour, steady vs flashing, and audience (aircraft in flight, aircraft on ground, or vehicle, equipment or person on the manoeuvring area) (TC AIM RAC 4.2.11 Table 4.2):
| Light | Aircraft in flight | Aircraft on ground | Vehicle, equipment or person |
|---|---|---|---|
| Steady green | Cleared to land | Cleared for take-off | Not used (aircraft-only) |
| Flashing green | Return for landing (steady green will follow) | Cleared to taxi | - |
| Series of green flashes | - | - | Cleared to cross, proceed, or go |
| Steady red | Give way and keep circling | Stop; wait for further clearance before proceeding (TC AIM RAC 4.2.10) | Stop, hold position |
| Flashing red | Do not land, aerodrome unsafe | Taxi clear of landing area | - |
| Series of red flashes | - | - | Vacate runway immediately |
| Flashing white | - | Return to starting point on aerodrome | Return to starting point on aerodrome (same meaning) |
| Blinking runway lights | - | Not an aircraft signal | Vacate active runway (vehicle-only) |
"-" = no meaning listed for that audience.
- Red pyrotechnic flare (military control towers only), in flight: do not land for the time being. Day or night, regardless of any earlier instructions (TC AIM RAC 4.4.7 Table 4.3).
Acknowledging (aircraft):
| Where | Day/Night | Action | Ref |
|---|---|---|---|
| In flight | Day | Rock aircraft | TC AIM RAC 4.4.7 |
| In flight | Night | Single flash of landing light | TC AIM RAC 4.4.7 |
| On ground | Day | Move rudder or ailerons, whichever is easiest to see, at least three times; or taxi to the authorized position | TC AIM RAC 4.2.10 |
Trap: same colour steady vs flashing, same signal air vs ground, or assuming an aircraft signal applies to vehicles (steady green is aircraft-only, blinking runway lights vehicle-only).
References
- TC AIM RAC 4.2.10
- TC AIM RAC 4.2.11
- TC AIM RAC 4.4.5
- TC AIM RAC 4.4.7
- PSTAR 6.21