airspace Class B

airspace Class B

A classification of airspace in which both IFR (instrument flight rules) and VFR (visual flight rules) flights are permitted and all flights are subject to air traffic control service and are separated from each other. Generally, it is that airspace from the surface to 10,000 ft MSL (mean sea level) surrounding the nation's busiest airports in terms of airport operation or passenger emplanements. The configuration of each Class B airspace area is individually tailored. It consists of a surface area and two or more layers and is designed to contain all published instrument procedures once an aircraft enters the airspace. Some Class B airspace areas resemble upside-down wedding cakes. An ATC (air traffic control) clearance is required for all aircraft to operate in the area, and all aircraft that are so cleared receive separation service within the airspace. The cloud clearance requirement for VFR operation is “clear of clouds.” Class B airspace is charted on sectional charts, IFR en route low-altitude charts, and terminal area charts. Formerly known as TCA, or terminal control area.