a visual glide slope indicator (VGSI) consisting of only two light units normally situated on the left side of the runway in the form of a wing bar and indicating that the aircraft is on slope if the

instrument that enabling the approach procedure to be performed with accuracy and safety, mõõtevahend, mis annab piloodile täpset visuaalset teavet, võimaldades piloodil lähenemisprotseduuri läbi viia täpselt ja ohutult