Classification of Airspace
Classification of Airspace
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11.Nov.2025
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SKYbrary Aviation Safety. (November 11, 2025). Classification of Airspace.
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ATS airspace is classified and designated in accordance with the following:
Class A. IFR flights only are permitted, all flights are provided with air traffic control service and are separated from each other.
Class B. IFR and VFR flights are permitted, all flights are provided with air traffic control service and are separated from each other.
Class C. IFR and VFR flights are permitted, all flights are provided with air traffic control service and IFR flights are separated from other IFR flights and from VFR flights. VFR flights are separated from IFR flights and receive traffic information in respect of other VFR flights.
Class D. IFR and VFR flights are permitted and all flights are provided with air traffic control service, IFR flights are separated from other IFR flights and receive traffic information in respect of VFR flights, VFR flights receive traffic information in respect of all other flights.
Class E. IFR and VFR flights are permitted, IFR flights are provided with air traffic control service and are separated from other IFR flights. All flights receive traffic information as far as is practical. Class E shall not be used for control zones.
Class F. IFR and VFR flights are permitted, all participating IFR flights receive an air traffic advisory service and all flights receive flight information service if requested.
Class G. IFR and VFR flights are permitted and receive flight information service if requested.
(ICAO Annex 11: Air Traffic Services, Chapter 2, Section 2.6)
The services provided and flight requirements for different classes of airspace are shown in the table below.
| Class | Type of flight | Separation Provided | Service Provided | Speed limitation* | Radio communication requirement | Subject to an ATC clearance |
|---|---|---|---|---|---|---|
| A | IFR only | All aircraft | Air traffic control service | Not applicable | Continuous two-way | Yes |
| B | IFR | All aircraft | Air traffic control service | Not applicable | Continuous two-way | Yes |
| VFR | All aircraft | Air traffic control service | Not applicable | Continuous two-way | Yes | |
| C | IFR |
IFR from IFR IFR from VFR |
Air traffic control service | Not applicable | Continuous two-way | Yes |
| VFR | VFR from IFR |
1) Air traffic control service for separation from IFR 2) VFR/VFR traffic information service (and traffic avoidance advice on request) |
250 kts IAS below 10000 ft amsl | Continuous two-way | Yes | |
| D (1) | IFR | IFR from IFR | Air traffic control service, traffic information about VFR flights (and traffic avoidance advice on request) | 250 kts IAS below 10000 ft amsl | Continuous two-way | Yes |
| VFR | Nil | IFR/VFR and VFR/VFR traffic information (and traffic avoidance advice on request) | 250 kts IAS below 10000 ft amsl | Continuous two-way | Yes | |
| E (2) | IFR | IFR from IFR | Air traffic control service and, as far as practical traffic information about VFR flights | 250 kts IAS below 10000 ft amsl | Continuous two-way | Yes |
| VFR | Nil | Traffic information as far as practical | 250 kts IAS below 10000 ft amsl | No | No | |
| F | IFR | IFR from IFR as far as practical | Air traffic advisory service; flight information service | 250 kts IAS below 10000 ft amsl | Continuous two-way | No |
| VFR | Nil | Flight information service | 250 kts IAS below 10000 ft amsl | No | No | |
| G | IFR | Nil | Flight information service | 250 kts IAS below 10000 ft amsl | Continuous two-way | No |
| VFR | Nil | Flight information service | 250 kts IAS below 10000 ft amsl | No | No | |
| * When the height of the transition altitude is lower than 10,000 ft amsl, FL100 should be used in lieu of 10000 ft | ||||||
(ICAO Annex 11: Air Traffic Services, Chapter 2, Appendix 4)
Important Notes:
(1): In Class D airspace, both IFR and VFR traffic are required to follow ATC clearances; however, ATC are only responsible for IFR against IFR separation.
(2): In Class E airspace, ATC does not provide separation between IFR and VFR traffic; IFR traffic shares responsibility for separation from uncontrolled VFR traffic with that traffic.
Further Reading
- ICAO Annex 11 Chapter 2 and Appendix 4
- EU Regulation 923/2012 (consolidated version, external link), SERA.6001
Categories
What Links Here (53)
- Loss of Separation
- Airspace Infringement
- Notified Airspace
- Controlled Airspace
- Control Zone (CTR)
- Advisory Service
- Air Traffic Control Service
- Air Traffic Service (ATS)
- ATC Clearance
- Flight Information Service
- North Atlantic Operations - Airspace
- Radio Mandatory Zone (RMZ)
- Transponder Mandatory Zone (TMZ)
- A343 / GLID, en-route, north of Waldshut-Tiengen southwest Germany, 2012
- AT76, vicinity Moranbah Queensland Australia, 2013
- C525 / P180, south west of Sion Switzerland, 2012
- DH8A / Z42, vicinity Sault Ste. Marie ON Canada, 2014
- B738 / AS25, en-route, near Frankfurt Hahn Germany, 2013
- B738 / F100, Geneva Switzerland, 2014
- E170 / F900, en-route, east of Varna Bulgaria, 2015
- H25B / AS29, en-route / manoeuvring, near Smith NV USA, 2006
- F900 / B772, en-route, near Kihnu Island Estonia, 2013
- DH8B / BN2P, Horn Island QLD Australia, 2016
- C525 / C42, en-route / manoeuvring, near Eastbourne UK, 2017
- A321 / B738, en-route, south eastern Bulgaria, 2016
- C130 / C27J, manoeuvring, near Mackall AAF NC USA, 2014
- A319 / AS32, vicinity Marseille France, 2016
- B77W, en-route, northeast of Los Angeles USA, 2016
- European Airspace Infringement Action Plan
- Glider Launch Site Risks
- Midair Collision
- Non-Aerodrome FIS Outside of Controlled Airspace (UK)
- Own Separation
- Right-of-way
- See and Avoid
- Traffic Information Broadcasts by Aircraft (TIBA)
- Deviation from ATC Clearance - Parachute Dropping
- Unauthorised Penetration of Airspace
- Empty Field Myopia
- Inadvertent VFR Flight Into IMC
- ICAO Emergency Phases
- Using GNSS as a VFR Navigation Tool
- VFR on Top
- Regulation 923/2012 Common Rules of the Air and Operational Provisions Regarding Services and Procedures in Air Navigation
- VFR over-the-top
- Traffic Information
- A320 / E195, vicinity Brussels Belgium, 2018
- CRJX / AT75, Tambolaka Indonesia, 2018
- S76, en-route, northwest of Los Angeles USA, 2020
- How Air Traffic Control Works
- Discrete and Non-discrete SSR Codes
- U-space
- The FIS Officer
