What does a blue boundary indicate on an aeronautical chart?

A blue boundary on an aeronautical chart indicates Class B Airspace. Class B Airspace is typically found around the busiest airports and is designed to provide positive control for aircraft operating in that area. To enter this airspace, pilots must obtain clearance from Air Traffic Control, which helps maintain safety and efficiency in areas with high volumes of air traffic.

Class B boundaries are depicted in blue on sectional charts, often surrounding major metropolitan airports. The airspace usually extends from the surface up to a specific altitude, and it is segmented into different layers that pilots must navigate through. Understanding the visual representation of Class B Airspace is essential for pilots to ensure they follow appropriate procedures for entry and operation within this controlled airspace environment.