A blue segmented circle on a Sectional Chart depicts which class airspace?

A blue segmented circle on a Sectional Chart represents Class D airspace. This type of airspace is typically found around airports that have an operational control tower. The blue segmented circle is used to indicate the boundaries of this airspace, which extends from the surface of the earth up to an altitude of 2,500 feet above the airport elevation.

Class D airspace allows for a mix of both IFR (Instrument Flight Rules) and VFR (Visual Flight Rules) operations, but it is crucial for pilots to maintain communication with air traffic control while operating within this airspace. The segmentation of the circle signifies that there are special procedures and requirements that pilots must be aware of when flying in and out of this airspace.

The other classes of airspace have distinct features, such as solid blue circles for Class B airspace which indicate more complex and higher altitude environments, or Class C airspace which is depicted as a solid magenta circle and typically involves airports with a two-way radio communication requirement. Understanding the characteristics of each class is essential for safe navigation in the National Airspace System.