The airspace around the busiest US airports is classified as ICAO Class B, and the primary airport (one or more) for which this airspace is designated is called Class B airport. As of January 2023, there are 37 Class B airports in the United States.
Class B airspace surrounds the busiest airports from the surface to 10,000 feet MSL. The dimensions of Class B airspace vary depending on the needs of the airport. Class C airspace extends from the surface to 4,000 feet MSL.
The United States Federal Aviation Administration (FAA) has a system for categorizing public-use airports (along with heliports and other aviation bases) that is primarily based on the level of commercial passenger traffic through each facility.
Class I airport means an airport certificated to serve scheduled operations of large air carrier aircraft that can also serve unscheduled passenger operations of large air carrier aircraft and/or scheduled operations of small air carrier aircraft.
DCA and LGA are Level 3 airports with primarily domestic or pre-cleared international operations. Allocations are on a continuing basis based on historic slots, a two-month minimum usage requirement, and other provisions in the FAA order and rules.
Class C airspace is used around airports with a moderate traffic level.Class D is used for smaller airports that have a control tower. The U.S. uses a modified version of the ICAO class C and D airspace, where only radio contact with ATC rather than an ATC clearance is required for VFR operations.
Class C Airspace (Mandatory Radar)A shelf area with an outer radius of 10 nautical miles surrounds the core area. It extends from 1200 feet AGL to 4000 feet AGL. The airspace is depicted on charts as 2 concentric magenta circles.
In aviation, a control zone (CTR) is a volume of controlled airspace, usually situated below a control area, normally around an airport, which extends from the surface to a specified upper limit, established to protect air traffic operating to and from that airport.
Can we fly over it? Technically yes, BUT it's still a very bad idea because a motor out would force you to descend through the Class C airspace. We CAN'T fly here without special permission from ATC. Permission should be obtained in advance by telephone (some controllers will accept a radio call).
Class D airports have an Air Traffic Control Tower to coordinate airport operations. However, unlike Class B and C airports, they don't require a mandatory approach and departure control (though many do have approach/departure).
Airports are locally owned and operated.All but one U.S. commercial airport are owned and operated by public entities, including local, regional or state authorities with the power to issue bonds to finance some of their capital needs.
Because Kennedy, LaGuardia, and Newark are so close, the Class B airspace for the three airports overlaps. Class B airspace is often described as an upside-down wedding cake (see accompanying picture). The top of the airspace is 7,000 feet above sea level for New York's Class B.
Like most controlled airspace, ALL pilots must notify and receive approval from the FAA to fly in Class C airspace. Pilots must also follow the necessary procedure to receive permission. Approval cannot be granted by control towers individually; the request must be sent using one of two methods.