Which way do runway lights face?
Fixture orientation: edge and centreline lights face both ways, touchdown zone lights face the approach, and threshold and end lights show green outward and red inward.
Fixture orientation is the direction, or directions, a runway light faces relative to the runway. It decides who sees the light and which colour they see. Edge lights and centreline lights are normally bidirectional, sending a beam each way along the runway so one fixture serves aircraft in both directions. Touchdown zone lights are unidirectional: they face the approach, so a runway used both ways has a separate set for each direction.
Threshold and runway end lights are often a single two-colour fixture. It shows green outward to aircraft approaching, and red inward toward the runway, so the same row is the threshold for one direction and the runway end for the other. Near the far end of a runway the centreline lights (where provided) change to alternating red and white and then red, and the edge lights may show yellow, so each direction of a fixture can show a different colour.
Orientation is about which way a fixture faces; how precisely it is aimed is covered by fixture alignment in the next entry. It builds on beam direction and the beam entries before this one: the edge-light beam, the threshold-light beam and the TDZ beam. A fixture installed turned the wrong way round is a serious fault: a one-way light then faces away from the pilot, and a two-colour fixture turned 180° swaps its colours.
Frequently Asked Questions
Q1What is runway light fixture orientation?
The direction or directions a runway light faces relative to the runway: whether its beam goes one way, both ways along the runway, and which colour is shown in each direction.
Q2Which runway lights are unidirectional and which are bidirectional?
Edge lights and centreline lights are normally bidirectional, serving aircraft in either direction. Touchdown zone lights are unidirectional, facing the approach. Threshold and runway end lights are often one fixture that shows green outward to the approach and red inward toward the runway.
Q3What happens if a fixture is installed turned the wrong way round?
A unidirectional light then faces away from the pilot it is meant to guide and is not seen from the approach. A two-colour fixture turned 180 degrees swaps its colours, so a pilot could see red where green is intended or the reverse. Orientation is therefore checked at installation and again after any fixture replacement.
Q4How is the orientation of a fixture checked?
Against the runway axis and the fixture's own alignment marking or reference during installation, then by a visual check from the approach and from the runway at night, and by photometric or flight checks where required. Follow the manufacturer's installation instructions.
Q5Where is the orientation of runway lights defined?
In the runway lighting chapters of ICAO Annex 14, Volume I (Chapter 5), which state the direction and colour each light must show, with the colours in Appendix 1 and the beam shapes in Appendix 2, and in FAA AC 150/5340-30 and AC 150/5345-46 and the fixture manufacturer's data. Always confirm against the current edition.
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