Runway end lights show red at the runway end; green marks the threshold. Learn each colour and avoid confusing PAPI, REIL and runway edge lights.
Runway end lights are a transverse row marking the end of the declared runway. They show red towards aircraft on the runway. Green lights viewed from the approach side mark the landing threshold; combined threshold/end fittings may therefore appear green from one direction and red from the other.
In aviation and real-world flying, viewing direction is the crucial detail. The fitting does not change colour as an aircraft passes it: directional lenses present the appropriate colour to traffic approaching from each side.
What colour are runway end lights?
Steady red is the runway-end indication seen by an aircraft travelling towards the far end of a runway.
| View and position | Colour seen | Meaning |
|---|---|---|
| Looking towards the far end while on the runway | Steady red | The declared runway ends at this transverse row. |
| Approaching the landing threshold from outside the runway | Steady green | The runway available for landing begins here. |
| Approaching the same extremity in the reciprocal direction | Steady green | That extremity is now the threshold for the opposite runway direction. |
Green threshold lights identify runway geometry; they do not constitute permission to land. For the surrounding edge, centreline and touchdown-zone indications, see our explanation of the complete runway-lighting pattern.
Why can one row look red from one direction and green from the other?
Many runway extremities use directional or combined threshold/end fittings because the same location serves two different purposes.
Consider a runway designated 09/27. On final for Runway 09, the near row appears green and marks the Runway 09 threshold. The row at the far end appears red. Approaching from the opposite side to land on Runway 27, that far row is now viewed from its green threshold side.
This directional design also explains why lights may disappear, dim or appear different from a side-on simulator camera. They are intended to be viewed within a defined beam from the runway or approach path.
Do red end lights always mark the end of the pavement?
No: red end lights mark the declared runway boundary, which is not necessarily the physical end of every paved surface.
A stopway, blast pad or other paved area may continue beyond the red row, but it is not additional runway for a normal take-off or landing. At the approach end, a displaced threshold can place the green threshold lights partway down the pavement. The area before that threshold is unavailable for touchdown from that direction, although its permitted use for taxiing, take-off or opposite-direction rollout depends on the published layout.
Red runway end lights also do not mean the runway is closed. Closures use separate markings or signals; our guide to interpreting runway markings and signs covers those visual distinctions.
Which airport lights are commonly mistaken for runway end lights?
Several other lighting systems use red, green, yellow or flashing white signals, but they serve different purposes:
- PAPI lights: usually four red-and-white units beside the runway that indicate whether the aircraft is above, on or below the approach slope. They do not mark the runway end. Our practical guide explains how to read PAPI indications in a flight simulator.
- Runway End Identifier Lights: despite the name, REILs are a pair of synchronised flashing white lights beside the approach threshold. They help pilots locate the runway entrance.
- Runway edge lights: these run along both sides. On some instrument-lighting systems, white edge lights change to yellow or amber through the caution zone near the departure end.
- Stop bars: a row of red lights across a taxiway marks a holding position. It is not the end of the runway and must not be crossed while illuminated.
Do all runways have runway end lights?
No. Small or unlit runways may have no runway lighting, while other airports illuminate their systems only during operating hours or after pilot activation.
If no end lights are visible, do not infer either that the runway continues or that it is closed. Check the published runway information, lighting availability and any ATC instructions. Weather, intensity settings and the narrow viewing angle of directional lights can also make a working system difficult to see.
How should you identify runway end lights in a simulator?
Use the same near-end green and far-end red relationship in MSFS, FSX, Prepar3D and X-Plane, while allowing for differences in individual airport scenery.
- Confirm the runway direction. Make sure the number selected in the flight plan or ATC instruction matches the end you are approaching.
- Check from the cockpit. View the lights on the extended centreline at dusk or night; a free camera positioned off to the side may sit outside their directional beam.
- Account for a displaced threshold. Follow the green threshold row and threshold markings rather than assuming the first piece of pavement is the touchdown point.
- Investigate incorrect colours or duplicate rows. Temporarily disable overlapping airport add-ons one at a time. Old airport data, duplicated scenery packages and simplified non-directional light effects are common causes.
During landing or a rejected take-off, treat the red transverse row as the firm runway limit. Simulator visual scaling and scenery placement are not reliable substitutes for calculated runway-length and stopping-distance requirements.