What is the minimum visibility required if the runway is equipped with PAPI/VASI?

The correct minimum visibility required for a runway equipped with Precision Approach Path Indicators (PAPI) or Visual Approach Slope Indicators (VASI) is indeed 3 miles. This is crucial because PAPI and VASI systems assist pilots in maintaining the correct approach glide path when landing. The visibility requirement ensures that pilots can adequately see these visual aids, which are essential for safety, especially in conditions that may impair visibility.

Having 3 miles of visibility allows enough distance for pilots to visually identify the PAPI or VASI signals, assess their alignment with the runway approach path, and make necessary adjustments during their descent. Adequate visibility also enhances situational awareness and permits pilots to make informed decisions about their approach and landing.

In contexts where visibility is lower than 3 miles, additional visual aids or procedural adjustments may be required to ensure safe landing operations, emphasizing the importance of this visibility standard in enhancing flight safety.