Aeronautical Information Manual (AIM), page 217
5/26/16
12/10/15 AIM
REFERENCE- 2. The directions transmitted by a light signal
AIM, Paragraph 4-1-9 , Traffic Advisory Practices at Airports Without
Operating Control Towers are very limited since only approval or disapproval of
a pilot's anticipated actions may be transmitted. No
supplement or explanatory information may be
4-3-13. Traffic Control Light Signals transmitted except by the use of the "General
a. The following procedures are used by ATCTs in Warning Signal" which advises the pilot to be on the
the control of aircraft, ground vehicles, equipment, alert.
and personnel not equipped with radio. These same c. Between sunset and sunrise, a pilot wishing to
procedures will be used to control aircraft, ground attract the attention of the control tower should turn
vehicles, equipment, and personnel equipped with on a landing light and taxi the aircraft into a position,
radio if radio contact cannot be established. ATC clear of the active runway, so that light is visible to the
personnel use a directive traffic control signal which tower. The landing light should remain on until
emits an intense narrow light beam of a selected color appropriate signals are received from the tower.
(either red, white, or green) when controlling traffic
by light signals. d. Airport Traffic Control Tower Light Gun
Signals. (See TBL 4-3-1.)
b. Although the traffic signal light offers the
advantage that some control may be exercised over e. During daylight hours, acknowledge tower
nonradio equipped aircraft, pilots should be cog- transmissions or light signals by moving the ailerons
nizant of the disadvantages which are: or rudder. At night, acknowledge by blinking the
landing or navigation lights. If radio malfunction
1. Pilots may not be looking at the control tower occurs after departing the parking area, watch the
at the time a signal is directed toward their aircraft. tower for light signals or monitor tower frequency.
TBL 4-3-1
Airport Traffic Control Tower Light Gun Signals
Meaning
Movement of Vehicles,
Color and Type of Signal Equipment and Personnel Aircraft on the Ground Aircraft in Flight
Steady green Cleared to cross, proceed or go Cleared for takeoff Cleared to land
Flashing green Not applicable Cleared for taxi Return for landing (to be
followed by steady green at the
proper time)
Steady red STOP STOP Give way to other aircraft and
continue circling
Flashing red Clear the taxiway/runway Taxi clear of the runway in use Airport unsafe, do not land
Flashing white Return to starting point on airport Return to starting point on airport Not applicable
Alternating red and green Exercise extreme caution Exercise extreme caution Exercise extreme caution
4-3-14. Communications as soon as practical consistent with other ATC
requirements.
a. Pilots of departing aircraft should communicate REFERENCE-
AIM, Paragraph 4-1-13 , Automatic Terminal Information Service
with the control tower on the appropriate ground (ATIS)
control/clearance delivery frequency prior to starting b. The tower controller will consider that pilots of
engines to receive engine start time, taxi and/or turbine-powered aircraft are ready for takeoff when
clearance information. Unless otherwise advised by they reach the runway or warm-up block unless
the tower, remain on that frequency during taxiing advised otherwise.
and runup, then change to local control frequency
when ready to request takeoff clearance. c. The majority of ground control frequencies are
in the 121.6-121.9 MHz bandwidth. Ground control
NOTE- frequencies are provided to eliminate frequency
Pilots are encouraged to monitor the local tower frequency congestion on the tower (local control) frequency and
Airport Operations 4-3-17
Page 217 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures