What do blue airspace boundaries indicate on a sectional chart?

Blue airspace boundaries on a sectional chart indicate Class B airspace. This type of airspace is typically found around major airports to manage high traffic volumes and to provide separation between commercial airline operations and general aviation.

Class B airspace extends from the surface up to a specified altitude and is usually depicted on sectional charts with solid blue lines. Pilots need to obtain clearance from air traffic control before entering Class B airspace, as it is designed to protect the safety and efficiency of air travel in busy areas. The outer areas of Class B airspace may sometimes include a 'shelf' layer, allowing aircraft to operate below the main Class B airspace without needing clearance.

Understanding the significance of blue boundaries is essential for safe navigation, particularly for pilots flying near busy airports where adherence to airspace regulations is crucial for avoiding conflicts and ensuring the safety of all air traffic.