PAPI and VASI glidepath lights are visible up to how many miles at night and how many miles during the day?

PAPI and VASI glidepath lights are visible up to how many miles at night and how many miles during the day?

• A. Night 5 miles; Day 20 miles
• B. Night 20 miles; Day 5 miles
• C. Night 10 miles; Day 15 miles
• D. Night 25 miles; Day 3 miles

Answer: (B)

PAPI and VASI provide visual cues for maintaining the correct glide slope, and their visibility distance depends on lighting conditions. In darkness, the lights stand out against the night sky, so they can be seen from farther away—about 20 miles. In daylight, the bright ambient light reduces their contrast and makes them harder to pick up, so they’re typically visible only up to about 5 miles. That combination—night around 20 miles and day around 5 miles—fits the standard guidance for these systems. Other options mix up the distances or imply daylight visibility beyond what’s practical, so they don’t match how these lights are observed in practice.

PAPI and VASI provide visual cues for maintaining the correct glide slope, and their visibility distance depends on lighting conditions. In darkness, the lights stand out against the night sky, so they can be seen from farther away—about 20 miles. In daylight, the bright ambient light reduces their contrast and makes them harder to pick up, so they’re typically visible only up to about 5 miles. That combination—night around 20 miles and day around 5 miles—fits the standard guidance for these systems. Other options mix up the distances or imply daylight visibility beyond what’s practical, so they don’t match how these lights are observed in practice.