Plain English Meaning

Two bright flashing lights, one on each side of the start of the runway, that flash together to help pilots quickly spot which runway to land on.

Full Definition

A pair of synchronized flashing white lights installed on each side of the runway threshold, used to provide rapid and positive identification of the approach end of a particular runway. REILs may be either omnidirectional or unidirectional facing the approach area, and are commonly installed at runways without other approach lighting systems or where the threshold might otherwise be hard to distinguish.

Context Anchor

You may see REIL while approaching a runway at night, in reduced visibility, or at an airport where other lights make the runway harder to .