I would like to talk to you about Airport lighting systems

There are a few lighting systems around an airport, they are used to light up the airport in low light and low visibility conditions.
These color coded lights are used from Runway and Taxiway lights, to approach assist lights and are all very important and useful when approaching an Airport at night or in low visibility (fog/weather).

These lights are controlled by the Tower at Tower operating times as some Towers close at night. (Pilots are required to have all the information about the airport they are landing at with them)

In most airports where the Tower Closes but the Runway remains operational the Pilot approaching the airport can control these lights by tapping his/her radio PTT button on airport frequency.
In most medium/big airport the pilot can control the brightness of these lights as well ;)
*In 1 second: 3 taps = low, 5 taps = medium, 7 taps = high

-Some airports may have a more limited lighting system, and some don't at all.
(usually small and private airfields)

-Some small Airports don't have a Tower at all, but most will have a Radio frequency for Pilots to communicate with each other around the airport airspace and operate the light system

I am not going to go over every light system, just the Important ones ;)

1-Taxi lights:

-GREEN Lights = Taxiway Centreline Light - mark Taxiway Center-line

-BLUE Lights = Taxiway Edge Lights - mark Taxiway Edge / Shoulder (boundary)

-YELLOW Lights in a line = Clearance Bar Lights - Mark area of attention such as Taxiway Intersections and Holding positions before entering the Runway
These cannot be crossed without Tower clearance!

-GREEN+YELLOW Bidirectional (Green one way, Yellow pointing at pilot) lights and Green Lights = Taxiway Lead Off/On - These lead from the Taxiway and onto the Runway and From the Runway to Taxiways.
Lead off/on Lights start from Taxiway Clearance Bar Lights and they guide to the Runway Centreline. (see top image to see Lead Off lights)

2-Runway Lights:

-Runway Edge Lighting - These White Lights are used to outline the edges of runways.
These light systems are classified according to their intensity:
*High intensity runway lights (HIRL)
*Medium intensity runway lights (MIRL)
*Low intensity runway lights (LIRL)

"When an approach must be made on instruments, the last 600 metres (2,000 ft), or half the runway length (whichever is less), are bi-directional. They look white to the pilot approaching from the short end of the runway, but to a pilot approaching from the other end, who would be landing or taking off in that direction, they are yellow to indicate that the runway is nearing the end." Wikipedia makes things easy to find sometimes ;)

-Runway Centerline Lighting system (RCLS) – White Lights at 50 ft (15 m) intervals along the runway centerline on some precision instrument runways.
*White except the last 900 m (3,000 ft):
*Alternate White and Red for next 600 m (1,969 ft)
*Red for last 300 m (984 ft).

-Runway Threshold Lights: The lights marking the last 200 metres (660 ft) of the runway, called Runway End Identifier Lights, or REILs, emit RED light toward the runway to indicate the end of the runway to aircraft on it, and GREEN light outward to indicate the threshold to landing aircraft.

-Runway End Identifier Lights (REIL): unidirectional (facing approach direction) or omnidirectional pair of synchronized Flashing White Lights installed at the runway threshold, one on each side.
These help Identify the Runway from surrounding lights at night or in low visibility conditions.

Would you like to know more?

3-Approach Assist Lights:
These systems use Visual light aid when approaching to land, by creating a "visual Glidepath" to the Runway touchdown area.
The ratio of white to red lights seen is dependent on the angle of approach to the runway. Above the designated glide slope a pilot will observe more white lights than red, at approaches below the ideal angle more red lights than white will be seen. For the optimum approach angle the ratio of white to red lights will remain equal throughout.
These systems consist of a pair or more of lights on the side of the runway, and usually lead the aircraft on a 3° glide slope.
These lights are coded as:

*WHITE = HIGH
*RED = LOW

The ratio of white to red lights seen is dependent on the angle of approach to the runway. Above the designated glide slope a pilot will observe more WHITE lights than RED, at approaches below the ideal angle more RED lights than WHITE will be seen. For the optimum approach angle the ratio of white to red lights will remain equal throughout.

-Visual approach slope indicator (VASI) lights:
This system uses 2 or 3 sets of Parallel lights at set distances to create glidepath:

-Precision approach path indicator (PAPI) lights:
This system uses a Line of lights to create the glidepath

Pilots use these to remember this while training:

WHITE on WHITE - "Check your height" (or "You're out of sight", or "Higher than a kite") (too high)
RED on WHITE – "You're all right"
RED on RED – "You're dead" (too low)

Next time is gonna be Airport Symbols... I know I wrote this before but I'm getting to it ;)

Check out my other lessons if you liked this:
Navigation/Position Lights

Runway Numbers.... What How and why

Traffic Patterns... Left, Right, up and down

Radio calls, how to Communicate as a Pilot in command.

Uncontrolled Simpleplanes Class G Communications... wait what?

Leave a comment about other things or information you'd like to read about...
as long as it's related to the subject, and I'll try to make a lesson about it :)

if you'd like me to Tag you on the next one just add @1 in the description ;)