What is the term for a pair of synchronized flashing lights located laterally on each side of the runway threshold that provides rapid and positive identification of the approach end of a runway?

• A. Runway visibility value (RVV)
• B. Runway End Identifier Lights (REIL)
• C. Runway Visual Range (RVR)
• D. Runway centerline lights

Answer: (B)

Runway End Identifier Lights are a pair of synchronized flashing lights placed on each side of the runway threshold to give rapid, positive identification of the approach end. They stand out to the pilot, especially in reduced visibility or at complex airports, so you can confirm the exact threshold you’re aiming for. The other options don’t fit this function: Runway Visual Range and Runway visibility value refer to visibility measurements, not lighting; Runway centerline lights run along the runway centerline, not laterally at the threshold.