What is the minimum visibility for landing?

Minimum Visibility for Landing

Safe aircraft landings require adequate visibility to ensure the pilot has a clear view of the runway and surrounding environment. The minimum visibility required for landing is determined by a combination of factors, including the type of aircraft, the instrument landing system (ILS) being used, and the runway lighting available.

Standard Minimum Visibility

For most commercial aircraft, the standard minimum visibility for landing is half a mile (0.8 kilometers). This minimum is based on the assumption that the aircraft is equipped with a Category I ILS, which provides lateral and vertical guidance to the runway. Additionally, the runway must be equipped with high-intensity runway lighting (HIRL) or medium-intensity approach lighting system with runway alignment indicator lights (MALSR).

Reduced Minimum Visibility

In some cases, it is possible to reduce the minimum visibility for landing below half a mile. This can be achieved through the use of enhanced lighting systems, such as:

• Precision Approach Path Indicator (PAPI): This system provides visual guidance to the pilot during the final approach, indicating whether the aircraft is above, below, or on the correct glide path.
• Visual Approach Slope Indicator (VASI): Similar to PAPI, VASI uses a series of lights to provide visual guidance during the final approach.
• Enhanced Visibility Runway Lighting System (EVR): This system uses high-intensity LED lights to improve runway visibility, particularly in low-visibility conditions.

With these enhanced lighting systems, the minimum visibility for landing can be reduced to as low as 3/8 of a mile (0.6 kilometers). This improved visibility allows pilots to land safely in challenging weather conditions, such as fog, rain, or snow.

Conclusion

The minimum visibility for aircraft landing is determined by a combination of factors, including the aircraft equipment, ILS, and runway lighting. With standard lighting, the minimum visibility is typically half a mile. However, enhanced lighting systems can reduce the minimum visibility to as low as 3/8 of a mile, improving safety in challenging weather conditions.