Every airport if it provides flight operations, has to be equipped with the lighting system. Airport lighting system helps pilots to do landing and takeoff safely at night, or in low visibility conditions. The critical part of airport lighting system is runway lights. They should be clearly visible, the should work continuously in all operating conditions, and, of course, they should be ICAO compliant (compliant with international aviation regulations).
Airport runway is the most important part of an airfield where aircraft does takeoff and landing. Runway has special markings identifying beginning and end of a runway, touchdown point, location of a runway, etc. However, at night marking are not visible for pilots. That’s why airport runway is additionally illuminated with runway lighting. The lights on a runway are of different types which will be described later in this article. Every type of lights has its own meaning and plays its own role.
Approach lights are the first lights that pilot will ‘reach’ during landing. They are of white color, unidirectional, blinking or steady type of lights. Approach lights are located prior to the runway. Their main function is to ‘show’ in what direction the runway is.
There are different type of runway approach. The simplest approach has a cross form and usually consists of 17 approach lights. This type approach lights is usually installed at regional and domestic airports.
The most advanced approach lighting system has a more complicated structure and includes lights of few colors – white, yellow, and red. You can see such system at huge air hubs like Dubai International Airport, Atlanta Airport, or Heathrow Airport.
Frequently named as Runway Threshold Identification Light (or RTIL), this is a white flashing light, unidirectional, that identifies beginning of a runway. Unlike approach lights, there only two RTIL lights installed per one side of a runway.
Runway Threshold Lights
Threshold lights are green color airfield lights, unidirectional type, installed at the beginning of the part of a runway where aircraft can do touchdown. Threshold is not a touchdown point yet. But this is a beginning of ‘safe-to-land’ part of a runway.
Runway edge lights are the most important lights on the airfield. They are located on the left and right sides of a runway (edges) and illuminate the part of the runway safe for landings.
Runway Edge Lights
Runway edge lights are of different colors, usually they are bidirectional. The most often used are white/white lights. Also, white/yellow, white/red, and yellow/red runway edge lights can be installed on the runway. Such differentiation of colors of runway edge lights is explained by the category of a runway, it’s length, and other factors. In simple words, more complicated is airfield – more colors you will see on the runway. The same story as with approach lights.
Runway end light identifies the end of a runway. It means that behind these lights, there is no place to continue aircraft movement. Runway end lights are unidirectional red color aviation lights.
Runway Threshold End Lights
Very often, airports use as kind of ‘combined’ solution: runway threshold end lights. This is a bidirectional green/red airfield light. From one direction it is green, from the other direction it is red. Threshold end lights are installed on the runways having threshold and runway end in the same location. It saves money. Because, in fact, airport will install twice less quantity of lighting fixtures comparing to acquiring set of unidirectional green threshold lights, and set of unidirectional red runway end lights.
Taxiway lights are blue color airfield lights installed on taxiways, and aprons. Taxiway is a part of airfield where aircraft is moving after landing to a runway. Taxiway lights are not so bright comparing to runway edge or threshold lights. And, they are almost invisible from the air. Actually, it’s not necessary. Because the pilot uses them only while moving on airfield.
PAPI Airport Lights
PAPI stands for Precision Approach Path Indicator. This is a bicolor light that helps a pilot to keep the correct path when approaching airport runway. PAPI lights are located on the left and right side of the runway, a little bit far from threshold lights.
Each PAPI light usually consists of four lighting fixtures (4 x Light House Assemblies). Each lighting unit can provide red or white light output. If aircraft is too low to the ground, all four lights will be of red color. If aircraft is too high, all 4 lights will be of white color. So, the correct path is when two lights are white and two lights are red.
Obstruction aviation lights are red color omnidirectional lights that illuminate airport buildings, obstructions, closed areas, temporarily unavailable areas on the airfield.
There are much more types of lights that you can see on a runway at night. We described above the most important and the most used types.
get a quoteThe color of runway light depends on its type and function. The most common types of airfield lights have been described above. Let’s summarize colors and types of the lights:
| Type of the Light | Colour |
| Approach lights | White |
| Runway Threshold Identification Lights | White |
| Threshold Lights | Green |
| Runway Edge Lights | White/white, white/yellow, white/red, yellow/red |
| Runway End Lights | Red |
| Threshold End Lights | Green/red |
| Taxiway Lights | Blue |
| PAPI Lights | White/red |
| Obstruction Aviation Lights, type A | Red |
Airports with non-precision runways usually install a simple runway lighting system that includes runway edge lights, PAPI lights, runway threshold end lights, and taxiway lights. Such a system is more than enough to secure flight operations of any regional and domestic airport having few flights per day. for In most cases, these airports serve local flight schools, private businesses, or emergency medical services.
S4GA solar permanent runway lighting is the perfect solution for this type of airport:
Runway lighting looks different at night. It depends on type of approach (precision or non-precision approach) and on category of a runway (CAT I,II,III).
Airfield lights can be ordered directly from airport lighting manufacturers, or from local AGL suppliers (distributors). Solar runway lighting applicable for non-precision approach runways – can be ordered directly from S4GA.
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