Runway End Identifier Lights (REIL) are two bright, flashing white lights located on either side of the runway's threshold . They help pilots identify the runway's location and orientation , especially in nighttime or low-visibility conditions .
1. Characteristics of REIL
✅ Bright white flashing light → Indicates the start location of the runway .
✅ Placed on both sides of the threshold → Left and right of the start of the track.
✅ Operates continuously or flashing → Depending on visibility and airport requirements.
✅ Improves the visibility of short or poorly lit runways .
✅ Adjustable intensity → Some systems dim the lights for better visibility.
2. Function of REIL
📌 Especially useful for :
✈ Night landings → Helps pilots locate the runway.
🌫 Bad weather (fog, rain, snow) → Provides additional visual reference.
🛑 Short or narrow runways → Increase visibility at smaller airports.
🔄 Aligned or Unaligned Approach → Helps pilots correct their approach angle.
3. Difference between REIL and other landing lights
| Lighting system | Location | Goal | Colour |
|---|---|---|---|
| REIL | At the beginning (threshold) of the track | Identifies the start of the runway | Flashing white |
| Threshold Lights | In a line across the width of the track | Marks the start of the landing zone | Solid green |
| Approach Lights (ALS, MALSR, ALSF-1, ALSF-2) | Before the runway | Guides the pilot to the runway | White & red |
| Runway Edge Lights | Along the edges of the track | Indicates the edges of the runway | White (or yellow at the end) |
4. Where are REILs used?
📍 Small and regional airports → Where extensive approach lighting is lacking.
📍 Airports with short runways → To assist pilots with runway recognition.
📍 Military airfields → Fast and precise identification during night operations.
📍 Airports in rough terrain → Where the runway is difficult to distinguish.
💡 In short:
Runway End Identifier Lights (REIL) are two flashing white lights at the runway entrance that help pilots locate the runway. They are primarily used at smaller or poorly visible airports and improve safety during nighttime and low-visibility landings .