Apron Markings Signs Handbook 【8K 2027】

Chipped or peeling paint is a FOD hazard. Markings must be repainted when retroreflectivity falls below 80% of original value (typically every 12–18 months in temperate climates; 6–9 months in heavy snow/sanding climates).

To be "solid," a handbook must specify physics. Apron Markings Signs Handbook

For the average passenger, an airport ramp (or apron) is simply the expanse of concrete where planes park. But for pilots, ground handlers, and air traffic controllers, it is a highly complex grid of invisible highways, safety zones, and parking spots. Chipped or peeling paint is a FOD hazard

Yellow solid lines that guide the nose wheel of an aircraft toward a specific parking position or gate. and air traffic controllers