2.3 Classification of Airspace

2.3.1 All the sections of airspace are classified according to the flight rules that apply within each particular airspace and the type of ATC service (if provided).

The classes are Class A, B, C, D, E, F & G.
Note: In the XZ division, we only use 3 of the classes, namely A, C and G. They are the ones in bold.

Class	Type Of Flight	Separation Provided	Service Provided	Communication Requirements	Clearance Required
A	IFR Only	All aircraft	Air traffic control service	Continuous two way	Yes
B	IFR VFR	All aircraft	Air traffic control service Air traffic control service	Continuous two way Continuous two way	Yes Yes
C	IFR VFR	IFR from IFR IFR from VFR VFR from VFR	Air traffic control service IFR sep from VFR VFR from VFR by traffic info	Continuous two way Continuous two way	Yes Yes
D	IFR VFR	IFR from IFR Nil	ATC service including traffic info about VFR flights (& traffic avoidance advise on request) Traffic information between VFR & IFR.	Continuous two way Continuous two way	Yes Yes
E	IFR VFR	IFR from IFR Nil	ATC service including traffic info about VFR flights as far as practicable Traffic info as far as practicable	Continuous two way No	Yes No
F	IFR VFR	IFR from IFR Nil	Air traffic advisory service Flight information service Flight information service	Continuous two way or by aircraft relay Continuous two way or by aircraft relay	No No
G	IFR	Nil Nil	Flight information service Flight information service	Continuous two way No	No No

2.3.2 A very simplified diagram of airspace commonly found in the XZ division.
types_of_airspace

2.3.2.1 The CTA (includes the UTA above it, not shown) is usually controlled by an Area Controller.

2.3.2.2 The CTA is always Class A or C and vertically stops at FL245, the UTA is always Class A as it only exists FL245 and above.

The vertical limits of the airways shown on either side of the CTA are usually low enough to join to a TMA as well.

2.3.2.3 The TMA is usually controlled by an Approach controller and is always Class C.

2.3.2.4 The CTR is always controlled by an Aerodrome controller and is always Class C.

2.3.2.5 Airspace laterally below a TMA, but excluding CTRs & ATZs are sometimes classified as a Special Rules Area (SRA), this is uncontrolled airspace.

3.2.6 All airspace thus outside of CTRs, TMAs, CTAs/UTAs are uncontrolled airspace, which in XZ division is Class G airspace.

Note: The classes and the types of airspace described above is typical for the XZ division, and not necessarily the same in other parts of the world.