ENR 1.4  ATS AIRSPACE CLASSIFICATION AND DESCRIPTION

1.4.1.  ATS airspace classification

ATS airspaces are classified and designated in accordance with the following:

Class A. IFR flights only are permitted, all flights are subject to air traffic control service and are separated from each other.

Class B. IFR and VFR flights are permitted, all flights are subject to air traffic control service and are separated from each other.

Class C. IFR and VFR flights are permitted, all flights are subject to 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 subject to 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 subject to air traffic control service and are separated from other IFR flights. All flights receive traffic information as far as is practical.

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.

The requirements for the flights within each class of airspace are as shown in the following table.

Table 1.4.1: ATS Airspace Classifications (Controlled)

Class

Type of flight

Separation provided

Service provided

VMC visibility and distance from cloud minima

Speed limitation*

Radio com munication requirement

ATC clearance

A

IFR only

All aircraft

Air traffic control service

Not applicable

Not applicable

Continuous two-way

Yes

B**

IFR

All aircraft

Air traffic control service

Not applicable

Not applicable

Continuous two-way

Yes

VFR

All aircraft

Air traffic control service

8 KM at and above 3050 M (10 000 FT) AMSL, 5 KM below 3050 M (10000 FT) AMSL Clear of clouds

Not applicable

Continuous two-way

Yes

IFR

IFR from IFR, IFR from VFR

Air traffic control serviceNot applicableNot applicableContinuous two - wayYes
C

VFR

VFR from IFR

  1. Air traffic control service for separation from IFR

  2. VFR / VFR traffic information (and traffic avoidance advice on request)

8 KM at and above 3050 M (10000FT) AMSL, 5 KM below 3050M (10000 FT) AMSL 1500 M horizontal;

300 M vertical distance from cloud

250 KT IAS below 3050 M (10000 FT) AMSL

Continuous two-way

Yes

D**

IFR

IFR from IFR

Air traffic control service including traffic information about VFR flights (and traffic avoidance advice on request)

Not applicable

250 KT IAS below 3050 M (10000 FT) MSL

Continuous two-way

Yes

VFR

Nil

Traffic information between VFR and IFR flights (and traffic avoidance advice on request)

8 KM at and above 3050 M (10000 FT) AMSL, 5 KM below 3050 M (10000 FT) AMSL 1500 M horizontal; 300 M vertical distance from cloud

250 KT IAS below 3050 M (10000 FT) AMSL

Continuous two-way

Yes

Class E**

IFRIFR from IFRAir traffic control service and traffic information about VFR flights as far as practicalNot applicable

250 KT IAS below 3050 M (10000 FT) AMSL

Continuous two-wayYes
VFRNilTraffic information as far as practical8 KM at and above 3050 M (10000 FT) AMSL, 5 KM below 3050 M (10000 FT) AMSL 1500 M horizontal; 300 M vertical distance from cloud

250 KT IAS below 3050 M (10000 FT) AMSL

NoNo

* When the height of a transition altitude lower than 3050 M (10000 FT) AMSL, FL 100 should be used in lieu of 10000 FT.

** Classes of airspace B, D and F are not used in SAL OCEANIC FIR / UIR.

*** When so prescribed by the appropriate ATS authority:

  1. lower flight visibilities to 1500 M may be permitted for flights operating:

    1. at speeds that, in the prevailing visibility, will give adequate opportunity to observe other traffic or any obstacles in time to avoid collision; or

    2. in circumstances in which the probability of encounters with other traffic would normally be low, e.g. in areas of low traffic volume and for aerial work at low levels.

  2. helicopters may be permitted to operate in less than 1500 M flight visibility, if manoeuvred at a speed that will give adequate opportunity to observe other traffic or any obstacles in time to avoid collision.

Table 1.4.2: ATS airspace Classifications (Uncontrolled)

Class

Type of flight

Separation provided

Service provided

VMC visibility and distance from cloud minima

Speed limitation*

Radio com munication requirement

ATC clearance

F**

IFR

IFR from IFR as practical

Air traffic advisory service, flight information service

Not applicable

250 KT IAS below 3050 M (10000 FT) AMSL

Continuous two - way

No

VFR

NIL

Flight Information Service

8 KM at and above 3050 M (10000 FT) AMSL,

1500 M horizontal; 300 M vertical distance from cloud.

At and below 900 M AMSL or 300 M above terrain whichever is higher - 5 KM*** clear of cloud and in sight of ground or water.

250 KT IAS below 3050 M (10000 FT) AMSL

No

No

G IFRNILFlight Information ServiceNot applicable

250 KT IAS below 3050 M (10000 FT) AMSL

Continuous two-wayNo
VFRNILFlight Information Service

8 KM at and above 3050 M (10000 FT) AMSL, 5 KM below 3050 M (10000 FT) AMSL, 1500 M horizontal; 300 M vertical distance from cloud

At and below 900 M AMSL or 300 M above terrain whichever is higher - 5 KM***, clear of cloud and in sight of ground or water

250 KT IAS below 3050 M (10000 FT) AMSL

NoNo

* When the height of a transition altitude lower than 3050 M (10000 FT) AMSL, FL 100 should be used in lieu of 10000 FT.

** Classes of airspace B, D and F are not used in SAL OCEANIC FIR / UIR.

*** When so prescribed by the appropriate ATS authority:

  1. lower flight visibilities to 1500 M may be permitted for flights operating:

    1. at speeds that, in the prevailing visibility, will give adequate opportunity to observe other traffic or any obstacles in time to avoid collision; or

    2. in circumstances in which the probability of encounters with other traffic would normally be low, e.g. in areas of low traffic volume and for aerial work at low levels.

  2. helicopters may be permitted to operate in less than 1500 M flight visibility, if manoeuvred at a speed that will give adequate opportunity to observe other traffic or any obstacles in time to avoid collision.