Definition of Visual Approach Slope Indicator (VASI)
The Visual Approach Slope Indicator (VASI) is a visual aid consisting of a series of lights that are arranged to guide pilots during the approach to a runway. It provides important information about the aircraft’s descent and helps the pilot to maintain the correct glidepath.
The VASI system is made up of a series of high-intensity red and white focused light beams. These light beams radiate in a directional pattern to indicate the aircraft’s vertical position relative to the landing surface. If the pilot is on the correct glidepath, he will see red lights over white lights. If the pilot is flying too high, he will see all white lights, while if he is flying too low, he will see all red lights.
The VASI system is typically installed at airports where the runway does not have an instrument landing system (ILS). It’s an essential tool for pilots, especially when visibility is low or during nighttime landings. Its role is critical in enhancing situational awareness for the pilot, helping them to make better decisions and adjustments during landing.
In summary, the Visual Approach Slope Indicator (VASI) is a vital tool that aids pilots in their descent during the approach to a runway, providing clear guidance on the aircraft’s position relative to the landing surface.
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