Airspace: Types, Categories, and Classes

• The National Airspace System (NAS) is divided into regulatory and non-regulatory airspace.

Airspace Types

• Controlled airspace (Classes A, B, C, D, and E)
• Uncontrolled airspace (Class G)
• Special Use airspace
• Other airspace

Airspace Categories and Types

• Determined by the complexity/density of aircraft movements
• Determined by the nature of operations conducted within the airspace
• Determined by the level of safety required
• Determined by national and public interest considerations

Class A Airspace

• Requires aircraft operation under Instrument Flight Rules (IFR), unless otherwise authorized by ATC
• Pilots must hold at least a private pilot certificate with an instrument rating
• Aircraft must have a two-way radio, Mode C transponder, ADS-B and TIS-B equipment operating on 1090 MHz ES frequency, and instruments/equipment for IFR operations
• Class A airspace is not specifically charted.

Class B Airspace

• For operation in Class B airspace, a pilot-in-command must hold at least a private pilot certificate
• Student pilots can operate in Class B airspace if they meet specific requirements of 14 CFR §61.94 or §61.95
• Minimum equipment includes an operable two-way radio for ATC communication, a Mode C altitude encoding transponder, and ADS-B Out equipment (UAT 978 MHz or 1090 MHz ES frequency)
• If operating IFR, an operable VOR or TACAN receiver or suitable RNAV system is needed
• Arriving aircraft must obtain ATC clearance before entering Class B airspace
• VFR operations require clear of clouds and at least 3 SM flight visibility
• Class B airspace is depicted on Sectional Charts, IFR En Route Low Altitude, and Terminal Area Charts with solid shaded blue lines indicating lateral limits
• Numbers on charts indicate base and top altitudes
• Speed is limited to no more than 200 knots (230 MPH) in Class B airspace designated for an airport or VFR corridor.

Class C Airspace

• Generally extends from the surface to 4,000 ft above the airport elevation (MSL)
• Surrounds airports with an operational control tower, radar approach control, and a certain number of IFR operations/passenger enplanements
• A student pilot certificate is the minimum pilot certification required
• Aircraft must have a two-way radio, Mode C capability, and ADS-B Out equipment (UAT 978 MHz or 1090 MHz ES)
• Two-way radio communications with ATC must be established and maintained while in Class C airspace
• Class C airspace is depicted on navigational charts with a solid magenta line, found on Sectional Charts, IFR En Route Low Altitude, and Terminal Area Charts
• ATC provides sequencing to the primary airport and Class C services within the airspace and outer area when two-way radio communications and radar contact are established
• Mode C transponder and ADS-B Out equipment are required in Class A, Class B, and Class C airspace, above the ceiling and within the lateral boundaries of Class B and Class C airspace (up to 10,000 ft MSL), and in Class E airspace at and above 10,000 ft MSL (excluding airspace below 2,500 ft AGL)

Class D Airspace

• When departing a satellite airport within Class D airspace without an operating control tower, two-way radio communications must be established and maintained with the relevant ATC facility as soon as practicable
• Class E airspace may be designated as extensions to Class B, C, D, and E surface areas
• Minimum weather conditions for VFR flight in Class D airspace: 3 SM flight visibility; cloud clearances of 500 ft below, 1,000 ft above, and 2,000 ft horizontal
• Class D airspace is depicted on Sectional and Terminal charts with blue segmented lines, and on IFR Enroute Lows with a boxed [D]
• No separation services are provided within Class D airspace.

Class E Airspace

• The airspace above FL 600 is Class E airspace
• Pilot certification: student pilot certificate
• Equipment: An operable radar beacon transponder with automatic altitude reporting capability and operable ADS-B Out equipment is required at and above 10,000 ft MSL within the 48 contiguous states and the District of Columbia, excluding the airspace at and below 2,500 ft above the surface
• Operable ADS-B Out equipment at and above 3,000 ft MSL over the Gulf of Mexico from the coastline of the United States out to 12 NM offshore
• When a Class C or Class D surface area is not continuously in effect, the surface area airspace changes to either a Class E surface area when the tower closes
• Communication with a tower located within Class E airspace is required unless otherwise authorized or required by ATC
• Class E airspace below 14,500 ft MSL is charted on Sectional and Terminal charts
• Class E surface extension areas are depicted by a magenta segmented line
• Visibility-3 SM, Cloud clearance— 500 feet below, 1,000 feet above, 2,000 feet horizontal applies to Class C,D, or E Airspace Less than 10,000 feet MSL
• Visibility-5 SM, Cloud clearance—1,000 feet below, 1,000 feet above, 1 SM horizontal. Applies to Class C,D, or E Airspace At or above 10,000 feet MSL

Class G Airspace

• Uncontrolled airspace or Class G airspace is the portion of the airspace that has not been designated as Class A, B, C, D, or E.
• It is therefore designated uncontrolled airspace.
• Class G airspace extends from the surface to the base of the overlying Class E airspace
• Although ATC has no authority or responsibility to control air traffic, pilots should remember there are visual flight rules (VFR) minimums that apply to Class G airspace
• Not required to establish communications with a tower located within Class G airspace

Special Use Airspace

• Prohibited areas contain airspace of defined dimensions where flight is prohibited for security or national welfare reasons
• Restricted areas contain airspace where flight is restricted, but not wholly prohibited Pilots should review Domestic Notices on the Federal NOTAM System website or the FAA SUA website for temporary restricted areas and MOAs

Other Airspace Areas

• Include local airport advisory, Military Training Routes (MTR), Temporary Flight Restriction (TFR), parachute jump aircraft operations, Published VFR routes, Terminal Radar Service Area (TRSA), Special Air Traffic Rules (SATR) and Special Flight Rules Area (SFRA)
• Military Training Routes are used by the military for low-altitude, high-speed training, typically above 1,500 ft AGL
• Special Flight Rules Area (SFRA) is airspace of defined dimensions where aircraft flight is subject to specific rules in Part 93, unless authorized by ATC
• An Air Defense Identification Zone (ADIZ) is an area of airspace over land or water requiring identification, location, and control of all aircraft (except Department of Defense and law enforcement) for national security
• Flight Plan—An IFR or DVFR flight plan must be filed and activated

Additional Airspace Information

• Class A*
• Vertical Dimensions: 18,000 ft MSL to FL600
• Entry Requirements: IFR, ATC clearance, instrument rating, two-way radio
• VFR Minimums: Not applicable (N/A)
• Class B*
• Vertical Dimensions: Surface to 10,000 ft MSL
• Entry Requirements: IFR and VFR need ATC clearance, private/student pilot, two-way radio
• VFR Minimums: 3 SM visibility, clear of clouds
• Class C*
• Vertical Dimensions: Surface to 4,000 ft AGL (charted MSL)
• Entry Requirements: IFR and VFR need ATC clearance (for IFR), radio contact for all, student certificate, two-way radio
• VFR Minimums: 3 SM visibility, 500 ft below, 1,000 ft above, and 2,000 ft horizontal from clouds
• Class D*
• Vertical Dimensions: Surface to 2,500 ft AGL (charted MSL)
• Entry Requirements: IFR and VFR need ATC clearance (for IFR), radio contact for all, student certificate, two-way radio
• VFR Minimums: 3 SM visibility, 500 ft below, 1,000 ft above, and 2,000 ft horizontal from clouds
• Class E*
• Vertical Dimensions: Except for 18,000 ft MSL, no defined vertical limit -- Extends upward from either the surface or a designated altitude to the overlying or adjacent controlled airspace
• Entry Requirements: IFR and VFR need ATC clearance (for IFR), Student certificate, two-way radio
• VFR Minimums: 3 SM visibility, 500 ft below, 1,000 ft above, and 2,000 ft horizontal from clouds*Different visibility minima and distance from cloud requirements exist for night operations, operations above 10,000 ft MSL, and operations below 1,200 ft AGL
• Class G*
• Vertical Dimensions: Surface up to the overlying controlled (Class E) airspace, not to exceed 14,500 ft MSL
• Entry Requirements: IFR and VFR, None, Student certificate
• VFR Minimums: 1 SM visibility, 500 ft below, 1,000 ft above, and 2,000 ft horizontal from clouds*Different visibility minima and distance from cloud requirements exist for night operations, operations above 10,000 ft MSL, and operations below 1,200 ft AGL