PAPI (Precision Approach Path Indicator) is a visual aid system used in aviation to help pilots maintain the correct glide path during an approach for landing. It consists of a set of lights positioned beside the runway, displaying combinations of red and white lights. The colors indicate whether the aircraft is too high, too low, or on the correct approach path. When pilots see two white and two red lights, they know they are on the correct glide slope. #AviationSafety #FlightOperations #PilotT

PAPIs are a series of lights by the runway threshold that provides visual descent guidance during final approach. Using a series of lenses and mirrors, these lights will tell you if you’re too high to make a stabilized approach, too low for obstacle/terrain clearance, or properly established on a roughly 3-degree glide path for landing. | Uretsky Aviation