ERAU Commercial Checkride Practice Test

In a tri-color VASI (Visual Approach Slope Indicator), the color green indicates that the aircraft is on the correct glide path. The VASI system is designed to provide visual guidance during the approach and landing phase of flight. When the green light is visible, it signifies that the aircraft is aligned with the optimal glide slope to safely approach the runway.

Understanding the function of the other colors can further solidify why green is the correct answer. An amber light typically indicates that the aircraft is slightly above the glide path, while a red light suggests that the aircraft is below the glide path. Therefore, green is the desired indication that assures pilots they are maintaining the proper descent trajectory. Recognizing these light signals is crucial for safe landings in varying visibility conditions.