What is the purpose of Runway End Identifier Lights (REIL)?

Runway End Identifier Lights (REIL) serve a critical function in aviation by enhancing the visibility of the runway's ending. These lights are typically installed at the two ends of a runway and emit a distinct visual signal that helps pilots identify the boundary of the runway, particularly during low-visibility conditions such as fog, rain, or nighttime operations. The presence of REIL assists pilots in aligning their approach to land safely, ensuring that they can clearly distinguish where the runway concludes. This is vital for maintaining safety and operational guidelines during landings, as it helps prevent overruns or missed approaches.