Page 133 - Planning and Design of Airports

102 Airp o r t Pl anning

Since aircraft flying in Class A airspace are generally fast moving com-
mercial airline or general aviation aircraft, all aircraft operating in
Class A airspace operate under IFR.
Class B airspace are defined areas within a 30 nm radius around
the busiest airports, including areas of multiple large airports, in the
United States. Class B airspace surrounds 36 of the busiest commer-
cial service airports in the United States. Class B airspace is typically
shaped in the form of what is known in the industry as an “inverted
wedding cake.” Nearest the busiest airports within the radius of Class B
airspace, Class B airspace extends from the surface of the busiest air-
ports in the area to generally 10,000 ft MSL. Farther away from the
airport, Class B may begin at some altitude above the surface and
extend to 10,000 ft MSL. The purpose of Class B airspace is to provide
an area of positive air traffic control to coordinate the many high-
speed aircraft transitioning from high altitudes to landing at the bus-
iest airports, and vice versa, with local lower altitude traffic within
the area, while providing airspace at lower altitudes further away
from the airport to be used with lower levels of control for smaller
and slower general aviation aircraft in the region. Aircraft operating
within Class B airspace are under positive air traffic control, and as
such must either be flying under IFR rules or, with permission from
air traffic control, under VFR rules with flight following. An example
depiction of Class B airspace is illustrated in Fig. 3-3. This illustration
is a portion of an airspace sectional chart, provided by the U.S.
Department of Defense and the Federal Aviation Administration as
one standard for identifying classes of airspace, airports, navigational
aids, and air routes in the NAS.
United States Airspace Class B Areas, centered around the follow-
ing civil airports:

• PHX Phoenix Sky Harbor International
• LAX Los Angeles International
• SAN San Diego International Lindbergh Field
• SFO San Francisco International
• DEN Denver International
• MIA Miami International
• MCO Orlando International
• TPA Tampa International
• HNL Honolulu International
• ORD Chicago O’Hare International
• CVG Cincinnati/Northern Kentucky International
• MSY Louis Armstrong New Orleans International
• BWI Baltimore/Washington International