Which color indicates airports with control towers underlying Class B, C, D, and E airspace on Sectional Aeronautical Charts?

The color that indicates airports with control towers underlying Class B, C, D, and E airspace on Sectional Aeronautical Charts is blue. This blue color is used to represent public-use airports that are controlled, providing pilots with easy identification of areas where air traffic control services are available. This is important for pilots to know as controlled airports have specific operational procedures that differ from uncontrolled airports.

Understanding the chart color coding is crucial for navigation and situational awareness, especially when flying in or out of busy airspace areas. The blue designation assists pilots in planning their routes and making informed decisions about flying in proximity to these controlled airspaces.