ENR 1.4 ATS AIRSPACE CLASSIFICATION AND DESCRIPTION

1. GENERAL

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

1.1 Class A

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

1.2 Class B (not used in the Muscat FIR)

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

1.3 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.

1.4 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.

1.5 Class E (not used in the Muscat FIR)

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 practicable.

1.6 Class F (not used in the Muscat FIR)

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.

1.7 Class G

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

2. REQUIREMENTS FOR FLIGHTS

The requirements for flights within each class of airspace are as shown in the table on pages ENR 1.4-2 and ENR 1.4-3.

Class Type of Flight Separation Provided Service Provided VMC Visibility and Distance from Cloud Minima Speed Limitation Radio Communication Requirement ATC Clearance
A
 IFR only
 All aircraft
 Air traffic control service
 Not applicable
 Not applicable
 Continuous two-way
 Yes
B(3)
 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 (10000 FT) AMSL 5 KM below 3050 M (10000 FT) AMSL Clear of clouds
 Not applicable
 Continuous two-way
 Yes
C
 IFR
 IFR from IFR IFR from VFR
 Air traffic control service
 Not applicable
 250 KT IAS below 3050 M (10000 FT) AMSL, unless advised by ATC.
 Continuous two-way
Yes
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 (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
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) AMSL
 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
E(3)
 IFR
 IFR from IFR
 Air traffic control service and traffic information about VFR flights as far as practical
 Not applicable
 250 KT IAS below 3050 M (10000 FT) AMSL
 Continuous two-way
 Yes
VFR
 Nil
 Traffic information as far as practical
 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
 No
 No
F(3)
 IFR
 IFR from IFR as far as practical
 Air traffic advisory service; flight information service, radar advisory service.
 Not applicable
 250 KT IAS below 3050 M (10000 FT) AMSL
 Continuous two-way
 No
VFR
 Nil
 Flight information service, radar advisory 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
 No
 No
G
 IFR
 Nil
 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 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 (1), clear of cloud and in sight of ground or water
 250 KT IAS below 3050 M (10000 FT) AMSL(2)
 No (Except continuous two-way required when operating in Class G at an aerodrome with ATS)
 No
(1) When so prescribed by the appropriate ATS authority:

(a) Lower flight visibilities to 1500 M may be permitted for flights operating:

1) at speeds that 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;

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

(2) Military operations are exempted from prescribed IAS restrictions below 10000 FT, provided that all the time a flight visibility of at least 8 KM is maintained.

(3) Classes of airspace B, E and F are not used in the Muscat FIR.