The convenience of modern air travel hides a brilliant secret. A secret language, generally known only by pilots. Seen by many, but understood by few. Twinkling and flashing all over airports runways, a series of messages are being transmitted by complex airport lighting systems.
For pilots to land safely, they need to see the runways, as they approach. When taking off and landing, they need to keep the aeroplane travelling safely down the runway. Even more importantly, they need to be aware of where the runway starts and ends. During the day a painted line may suffice, but at night, lights are necessary. But how can a pilot decide exactly which set of lights are the safest guide.
The lighting systems, which provide guidance to pilots, have been developed and standardized to minimize errors, and keep passengers safe. The system uses a pattern of coloured lights, to delineate the runway boundaries, and to designate specific features of the runway.
Runway End Identifier Lights
To show pilots on approach, where the runway begins, a pair of flashing white lights, one light on each side, are placed at the approach end of the runway. As the pilots approach the airport, these lights help to identify the runway from the taxiways.
Runway Edge Light Systems
To delineate the edges of a runway, a series of white lights line the edge of the runway. These lights are a solid white, and do not flash. To indicate to pilots, that a runway is nearing its end, the lights over the last 2000 feet or half the length of a small runway, change colour to yellow, then red over the last 1000 feet. These lights come in three intensity levels: high, medium and low.
Runway Centreline Lighting System
As a guide to pilots on precision runways, a centreline lighting system is used. The lighting is composed of white lights spaced every 50 feet, down the centreline of the runway. The last 1000 feet of the runway the lights are red. The centreline from 3000 feet remaining through to the red lights, are alternating red and white lights.
Touchdown Zone Lights
To show pilots the optimal place to touchdown, two rows of solid white lights are set parallel to the centreline, one row on each side. They extend from 100 feet past the landing threshold to the runway mid-point, or 3000 feet beyond the threshold.
Taxiway lead-off lights
These alternating yellow and green lights extend from the runway centreline, to an exit taxiway. These guide lights are used to move planes off the runway and into a safe taxiway quickly.
Land and Hold Short Lights
Occasionally airports require planes to remain on a runway and not taxi to a terminal. On these occasions, land and hold short lights are used. These lights are comprised of a row of white lights running across the runway, at the hold short position, which pulsate. While land and hold short operations are in progress, these lights will remain lit.