Definition
Green in-pavement lights that guide aircraft from the runway centerline onto the taxiway centerline after landing or during taxi operations in low-visibility conditions. They are part of the Surface Movement Guidance Control System (SMGCS) and lead aircraft off the runway and onto the correct taxi route.
Plain English
Green lights set into the pavement that show pilots the path to follow when leaving the runway and joining a taxiway, especially when visibility is poor.
Context Anchor
Seen while taxiing at larger airports, especially during low-visibility operations under a Surface Movement Guidance Control System.
Derivation
"Lead-on" means guiding someone onto something — in this case, leading the aircraft onto the taxiway. The name describes the lights' job: they lead you on from the runway to the taxiway.
Why Pilots Care
They provide precise visual guidance to prevent runway incursions and maintain safe separation during surface movement in reduced visibility.
Grounding Statement
At night or in fog, these lights form a line on the pavement that shows the path from the taxiway onto the runway.
Intuition Check
Do not assume “lead-on” means “cleared to go on.” These lights show the route onto the runway; air traffic control clearance is still required before entering.
Example Sentence 1
After landing in low visibility, the captain followed the green taxiway centerline lead-on lights off the runway and onto Taxiway Bravo.
Example Sentence 2
The lead-on lights changed from green to yellow as the aircraft approached the taxiway centerline.