What is the function of a VASIS?

The function of a VASIS (Visual Approach Slope Indicator System) is to provide visual guidance for approach angles. This system uses lights to indicate whether an aircraft is on the correct flight path to land safely on the runway. It assists pilots by showing if they are too high, too low, or on the proper glide slope for the approach, thereby helping maintain the appropriate descent angle.

By providing visual cues, the VASIS enhances safety during landing procedures, particularly in conditions where visibility may be compromised. The presence of this system is crucial for guiding pilots during the critical phase of landing, ensuring they have the necessary information to make adjustments to their approach as needed.