Airspace classification[PDF]

Introduction

Even if the sky may appear always the same, air traffic management requires the airspace to be divided in several classes, named by the first 7 alphabetic letters (A to G).
From A to G, airspaces become less restrictive.

In each airspace type, Air Traffic Services (ATS) provided and flight requirements change. As a rule of thumb, the best way for learning and not forget them is by noticing what is new in each airspace, regarding the previous. Below, all airspaces will be analysed.

Each State may also establish a limited region within the airspace, extending both vertically and horizontally where flying might be prohibited, restricted or to be conducted with caution.

There is a summary of this documentation found here.

Class A airspace

Class A airspace is a controlled airspace.
In class A airspace, only IFR flights are permitted (No VFR flights).

All flights are provided with air traffic control service and are separated from each other.

Type of flight Separation provided Services provided Speed limit Radio Communication ATC clearance
IFR Yes, between IFR Air Traffic Control, Flight Information, Alerting No Continuous, two ways Required
In some countries, VFR can be permitted in class A airspace under specific conditions and requirements. All exceptions are published on charts.

Class B airspace

Class B airspace is a controlled airspace. In class B airspace, IFR and VFR flights are permitted.

All flights are provided with air traffic control service and are separated from each other.

Type of flight Separation provided Services provided Speed limit Radio Communication ATC clearance
IFR Yes, between IFR and between IFR and VFR Air Traffic Control, Flight Information, Alerting No Continuous, two ways Required
VFR Yes, between VFR and between VFR and IFR Air Traffic Control, Flight Information, Alerting No Continuous, two ways Required

Class C airspace

Class C airspace is a controlled airspace. In class C airspace, 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 only traffic information with respect to other VFR flights.

Type of flight Separation provided Services provided Speed limit Radio Communication ATC clearance
IFR Yes, between IFR and between IFR and VFR Air Traffic Control, Flight Information, Alerting No Continuous, two ways Required
VFR Yes, between VFR and IFR. Only Traffic Information between VFR Air Traffic Control, Flight Information, Alerting 250KT below 10000ft/FL100 Continuous, two ways Required

Class D airspace

Class D airspace is a controlled airspace. In class D airspace, IFR and VFR flights are permitted.

All flights are provided with air traffic control service, IFR flights are separated from other IFR flights and receive traffic information with respect to VFR flights, VFR flights receive traffic information with respect to all other flights.

IFR aircraft are separated from VFR ones, but VFR aircraft are not separated from IFR ones. VFR needs not to be separated from IFR but they receive traffic information. The responsibility for separation is given to the VFR pilot.

This is known as essential traffic, which by definition means: controlled traffic to which ATC separation is applicable (in this case, IFR traffic) that is not or will not be separated from other particular controlled traffic (in this case, VFR traffic) by the appropriate separation minima.

Type of flight Separation provided Services provided Speed limit Radio Communication ATC clearance
IFR Yes, between IFR only. Traffic Information between IFR and VFR Air Traffic Control, Flight Information, Alerting 250KT below 10000ft/FL100 Continuous, two ways Required
VFR Only Traffic Information between VFR and between VFR and IFR Air Traffic Control, Flight Information, Alerting 250KT below 10000ft/FL100 Continuous, two ways Required
Note that Special VFR traffic shall be separated from other traffic like IFR ones. Special VFR flight is known as a VFR flight cleared by air traffic control to operate within a control zone in meteorological conditions below VMC.
Note that Special VFR rules exist only in some countries. Consult your country regulation publication if you are permitted to use this special rule.

Class E airspace

Class E airspace is a controlled airspace. In class E airspace, 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.

Type of flight Separation provided Services provided Speed limit Radio Communication ATC clearance
IFR Yes, between IFR only. Traffic Information between IFR and VFR Air Traffic Control, Flight Information, Alerting 250KT below 10000ft/FL100 Continuous, two ways Required
VFR Only Traffic Information between VFR and between VFR and IFR Flight Information, Alerting 250KT below 10000ft/FL100 Not required Not required

Class F airspace

Class F airspace is a non-controlled airspace. In class F airspace, IFR and VFR flights are permitted.

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.

Type of flight Separation provided Services provided Speed limit Radio Communication ATC clearance
IFR Traffic Information between VFR and IFR Flight Information, Alerting 250KT below 10000ft/FL100 Continuous, two ways Not Required
VFR No separation Flight Information on request, Alerting 250KT below 10000ft/FL100 Not required Not required
A non-controlled airspace is not equal to airspace without air traffic controllers.

Class G airspace

Class G airspace is a non-controlled airspace. In class G airspace, IFR and VFR flights are permitted.

IFR and VFR flights are permitted and receive flight information service if requested.

Type of flight Separation provided Services provided Speed limit Radio Communication ATC clearance
IFR No separation Flight Information on request, Alerting 250KT below 10000ft/FL100 Continuous, two ways Not Required
VFR No separation Flight Information on request, Alerting 250KT below 10000ft/FL100 Not required Not required
A non-controlled airspace is not equal to airspace without air traffic controllers.

See also

Reference

  • ICAO Documentation Annex 11 - Air Traffic Services - 14th Edition - July 2016 - Chapter 2.6


Author

  • VID 150259 - Creation
  • VID 150259 - Wiki integration

DATE OF SUBMISSION

  • 00:18, 14 May 2021

COPYRIGHT

  • This documentation is copyrighted as part of the intellectual property of the International Virtual Aviation Organisation.

DISCLAIMER

  • The content of this documentation is intended for aviation simulation only and must not be used for real aviation operations.