In a Tricolor VASI system, what color indicates that the aircraft is on the glideslope?

In a Tricolor VASI (Visual Approach Slope Indicator) system, a green light indicates that the aircraft is on the glideslope. The Tricolor VASI provides pilots with visual guidance during an approach, helping to ensure they maintain the correct descent path.

When the aircraft is on the proper glideslope, the pilot will see the green light, which signifies that the aircraft is at the correct altitude for landing. If the aircraft is below the glideslope, the light will switch to red, indicating that the aircraft is too low, and if it is above the glideslope, it will change to amber, signaling that the aircraft is too high.

This color-coding system provides immediate visual cues to help pilots make necessary adjustments in their approach, reinforcing the importance of maintaining the appropriate altitude for a safe landing.