Airport Engineering Planning, Design, and Development of 21st ...

6.2 U.S. National Airspace System (NAS) 191
Class B. Airspace extending from ground surface up to FL 10, surrounding the
busiest airports in terms of IFR operations or passenger enplanements. Class
B airspace is uniquely configured and individually tailored for the particular
airport airspace. It consists of a surface area and two or more layers designed to
contain all published instrument procedures once aircraft enter the airspace and
receive separation services. Class B airspace was called the terminal control
area (TCA), which is designated around major aviation hubs, and they include
at least one primary airport around which the TCA is located. Successive
layers of Class B airspace extend out of from the center of the airport and
are designed to provide ATC with sufficient airspace to vector aircraft to an
instrument approach at the primary airports. A typical Class B airspace is
depicted in Figure 6.5.
TCAs are classed as group I or II depending on the number of aircraft
operations and passengers they service. To operate within either group, the
aircraft must be equipped as per FAR 91.
Class C . Also known as Airport Radar Service Area (ARSA), and it is airspace
within the vicinity of medium-sized airports that do not qualify for TCA.
It is airspace extending from the surface to 4000 ft above airport elevation
surrounding airports that have an operational control tower, are serviced by
a radar approach control, and have a certain number of IFR operations or
passenger enplanements. While the configuration of each Class C airspace
area is individually tailored, the airspace usually consists of a 5-nautical-mi
radius core area that extends from the surface up to 4000 ft above the airport
elevation and a 10-nautical-mi radius shelf extending from 1200 to 4000 ft
above the airport. An outer area extends 20 nautical mi outward from the
center of the primary airport and extends from the lower limits of radar/radio
coverage up to the ceiling of the approach control’s delegated airspace.
ARSAs are established in busy medium to small airports to protect aircraft
which are landing or taking off. Aircraft wishing to enter an ARSA must
establish two-way radio communication with air traffic control. The services
provided by the ARSA on establishing two-way radio and radar contact are
sequencing arrivals, IFR/IFR standard separation, IFR/VFR traffic advisories
and conflict resolution, and VFR/VFR traffic advisories.
Class D. Airspace extending from the surface to 2500 ft above the airport elevation,
surrounding those airports that have an operational control tower. The
configuration of Class D airspace is individually tailored, and when instrument
procedures are published, the airspace will normally be designed to contain
the procedures.
IFR aircraft are authorized to operate in Class D airspace if their ATC
clearance routes them through it. VFR pilots are permitted to fly through
Class D airspace as long as the basic VFR weather conditions described in
FAR 91 exist and ATC permission is granted.
Class E. Controlled airspace that does not come under classes A, B, C, and D
airspace.
Class G. Uncontrolled within which ATC separation services will not be provided
to any aircraft, whether IFR or VFR. The burden of providing separation is