Aeronautical Information Manual (AIM), page 111

Index   110 -- Page 111 -- 112

b. The colors and color combinations of beacons

1. White and Green- Lighted land airport.

2. *Green alone- Lighted land airport.

3. White and Yellow- Lighted water airport.
4. *Yellow alone- Lighted water airport.

5. Green, Yellow, and White- Lighted heliport.
*Green alone or yellow alone is used only in connection
with a white-and-green or white-and-yellow beacon
display, respectively.
c. Military airport beacons flash alternately white
and green, but are differentiated from civil beacons
by dualpeaked (two quick) white flashes between the
green flashes.

d. In Class B, Class C, Class D and Class E surface
areas, operation of the airport beacon during the hours
of daylight often indicates that the ground visibility
is less than 3 miles and/or the ceiling is less than
1,000 feet. ATC clearance in accordance with
14 CFR Part 91 is required for landing, takeoff and

flight in the traffic pattern. Pilots should not rely

solely on the operation of the airport beacon to
indicate if weather conditions are IFR or VFR. At
some locations with operating control towers, ATC
personnel turn the beacon on or off when controls are
in the tower. At many airports the airport beacon is
turned on by a photoelectric cell or time clocks and
ATC personnel cannot control them. There is no
regulatory requirement for daylight operation and it
is the pilot's responsibility to comply with proper
preflight planning as required by 14 CFR
Section 91.103.

2-1-11. Taxiway Lights

a. Taxiway Edge Lights. Taxiway edge lights are
used to outline the edges of taxiways during periods
of darkness or restricted visibility conditions. These
fixtures emit blue light.
At most major airports these lights have variable intensity
settings and may be adjusted at pilot request or when
deemed necessary by the controller.
b. Taxiway Centerline Lights. Taxiway center-
line lights are used to facilitate ground traffic under
low visibility conditions. They are located along the
taxiway centerline in a straight line on straight

portions, on the centerline of curved portions, and
along designated taxiing paths in portions of
runways, ramp, and apron areas. Taxiway centerline

lights are steady burning and emit green light.

c. Clearance Bar Lights. Clearance bar lights
are installed at holding positions on taxiways in order
to increase the conspicuity of the holding position in
low visibility conditions. They may also be installed
to indicate the location of an intersecting taxiway
during periods of darkness. Clearance bars consist of
three in-pavement steady-burning yellow lights.

d. Runway Guard Lights. Runway guard lights
are installed at taxiway/runway intersections. They
are primarily used to enhance the conspicuity of
taxiway/runway intersections during low visibility
conditions, but may be used in all weather conditions.
Runway guard lights consist of either a pair of
elevated flashing yellow lights installed on either side
of the taxiway, or a row of in-pavement yellow lights
installed across the entire taxiway, at the runway
holding position marking.

Some airports may have a row of three or five in-pavement

yellow lights installed at taxiway/runway intersections.
They should not be confused with clearance bar lights
described in paragraph 2-1-11 c, Clearance Bar Lights.

e. Stop Bar Lights. Stop bar lights, when
installed, are used to confirm the ATC clearance to
enter or cross the active runway in low visibility
conditions (below 1,200 ft Runway Visual Range). A
stop bar consists of a row of red, unidirectional,
steady-burning in-pavement lights installed across
the entire taxiway at the runway holding position, and
elevated steady-burning red lights on each side. A
controlled stop bar is operated in conjunction with the
taxiway centerline lead-on lights which extend from

the stop bar toward the runway. Following the ATC
clearance to proceed, the stop bar is turned off and the
lead-on lights are turned on. The stop bar and lead-on
lights are automatically reset by a sensor or backup
Pilots should never cross a red illuminated stop bar, even
if an ATC clearance has been given to proceed onto or
across the runway.
If after crossing a stop bar, the taxiway centerline lead-on
lights inadvertently extinguish, pilots should hold their
position and contact ATC for further instructions.

Airport Lighting Aids 2-1-15

Page 111 of the Aeronautical Information Manual (AIM.pdf)
AIM: Official Guide to Basic Flight Information and ATC Procedures

Index   110 -- Page 111 -- 112