What color combination is used for an Aircraft Lead-in-Line?

The correct answer highlights a significant safety feature on airfields. An Aircraft Lead-in-Line is utilized to guide pilots from a taxiway to a runway. The color combination of yellow with a black border is specifically designed to ensure high visibility under various weather conditions and light levels, which is crucial for safe aircraft navigation.

Yellow is a color frequently associated with caution, and its use in this context alerts pilots to important directional information. The black border enhances the distinction of the line, making it stand out even more against the background of the taxiway or runway. This combination is standardized in aviation to maintain consistency across different facilities, enabling pilots to quickly recognize and follow these guidelines, thereby enhancing overall safety during taxi operations.