REIL are located where?

• A. At the threshold on the centerline
• B. Laterally on each side of the runway threshold
• C. On the approach lighting system
• D. At the far end of the runway

Answer: (B)

Runway End Identifier Lights (REIL) are designed to give you a quick, unambiguous cue to identify the threshold as you begin your approach. They consist of a pair of synchronized flashing lights placed laterally on each side of the runway threshold. That side-by-side placement makes the threshold easy to spot from the approach, and the flashing pattern is recognizable from a wide angle, helping you confirm you’re aligned with the threshold even in limited visibility. They are not located on the centerline, not at the far end, and they aren’t part of the approach lighting system, which is why the correct description is that they’re on the sides of the threshold.