lennuvälja maandumisraja kõrval paiknev pilootidele mõeldud visuaalne abivahend maandumise lihtsustamiseks, a visual glide slope indicator (VGSI) consisting of four light units normally situated on the left side of the runway (on both sides of the runway, in the case of the military) in the form of a wing bar and indicating that the aircraft is on slope if the two units nearest the runway show red and the two units furthest from the runway show white, too high if all units show white, and too low if all units show red

system of lights on the side of an airport runway threshold that provides visual descent guidance information during final approach, what generally located on the left-hand side of the runway approximately 300 meters beyond the landing threshold of the runway, lennuvälja maandumisraja kõrval paiknev pilootidele mõeldud visuaalne mõõte-/abivahend maandumise lihtsustamiseks, mis paikneb tavaliselt maandumisraja algusest umbes 300 meetri kaugusel