Light signals

Light Communications

Air Traffic Control (ATC) uses light signals to communicate with aircraft both in flight and on the ground. In flight, ATC uses flashing red lights to indicate a warning or prohibition, and a steady green light to signal clearance for takeoff or landing. On the ground, ATC uses red flashing lights to indicate stop and green flashing lights to indicate taxi and takeoff clearance. These signals are critical for ensuring safe and efficient air traffic operations, and pilots must be able to quickly interpret and respond to them. The table below contains the signals in force.

Light signals
On Ground	Light Mode	In Flight
Authorised to Take Off if pilot is satisfied that no collision risk exists	Green Static	Authorised to land if pilot is satisfied that no collision risk exists
Authorised to taxi if pilot is satisfied that no collision risk exists	Green flashing	Return for landing
Stop	Red Static	Give way to other aircraft Continue circling
Taxi clear of landing area in use	Red Flashing	Do not land Aerodrome unsafe
Return to starting point on aerodrome	White Flashing