Answer :
Final answer:
Runway End Identifier Lights (REILs) are installed at airfields for identification of the approach end of a runway, particularly useful during poor visibility conditions or at night.
Explanation:
The lighting systems installed at many airfields for rapid and positive identification of the approach end of a runway are the Runway End Identifier Lights (REILs). REILs are high-intensity strobe lights that flash in sequence to alert the pilot that they are approaching the runway threshold. These lights are typically installed at airports to enhance the visibility of the runway ends, especially in conditions where the approach sector is void of lighting, during poor weather conditions, or where the angle of approach to the runway is misleading.
Other lighting systems like Precision Approach Path Indicators (PAPIs), runway edge lights, and runway threshold lights serve different purposes. PAPIs provide visual descent guidance information during the approach, while runway edge lights outline the edges of the runway and threshold lights indicate the beginning of the runway that is available for landing.
