What does it indicate when approach lights are visible?

When approach lights are visible, it indicates that the aircraft is approaching the touchdown zone. These lights are designed to provide visual references to pilots during the final stages of landing. They help to enhance situational awareness by indicating the runway's location and the appropriate descent path, especially under low visibility conditions.

Seeing the approach lights is a critical cue for pilots, as it signifies that they are aligning properly with the runway and are on the right track for a safe landing. The presence of these lights suggests the aircraft is in the correct phase of approach, and it is a key factor in ensuring a successful touchdown. This visibility supports the pilot in making necessary adjustments to their approach based on the lights and other guidance provided.