Figure 5-12 -- Light gun.
Indoctrination courses and local rules that minimize vehicle traffic on aircraft movement
areas are established at all ATC facilities. But since vehicular traffic is sometimes
necessary, light signals may be used for controlling vehicles when the control tower has
a radio outage.
Control Light Signals
Besides the operation and limitations of the portable traffic light, you must know the
meaning of the traffic control light signals used. You can find the signals to use for
aircraft, vehicles, and personnel on the ground as well as the signals to use for aircraft
in the air in either the Aeronautical Information Manual or Air Traffic Control, FAA Order
Portable Traffic Control Light Flight Inspection Procedures
ground and the air.
Ground Ensure adequate coverage for operational control of ground traffic
Air Three miles in all quadrants at the lowest traffic pattern altitude