b. The colors and color combinations of beacons are: 

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. 

## NOTE − 

*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 − 10. 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. 

## NOTE 

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. 

## NOTE − 

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 − 10 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 timer. 

## CAUTION − 

Pilots should never cross a red illuminated stop bar, even if an ATC clearance has been given to proceed onto or across the runway. 

## NOTE − 

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. 

