8 The administration of Australian-administered airspace:
shall be in the best interests of Australia;
shall consider the current and future needs of the Australian aviation industry;
shall adopt proven international best practice airspace systems adapted to benefit Australia’s aviation environment; and
shall take advantage of advances in technology wherever practicable.
Airspace Classes Used in Australian-administered Airspace
9 Airspace administration in Australia is generally aligned with the International Civil Aviation Organization (ICAO) prescribed airspace classes and associated levels of service as set out in Annex 11 to the Convention on International Civil Aviation (1944) (Chicago Convention). Differences to the ICAO classes of airspace in Australia are notified to ICAO and listed in the Australian Aeronautical Information Publication (AIP).
10 The airspace classification system to be used in Australia is specified below:
Class A: IFR (instrument flight rules) flights only are permitted. All flights are provided with an Air Traffic Control (ATC) service and are separated from each other.
Class B: IFR and VFR (visual flight rules) flights are permitted; all flights are provided with ATC service and are separated from each other.
Class C: IFR and VFR flights are permitted. IFR flights are provided with an ATC service and are separated from both IFR and VFR flights. VFR flights are provided with an ATC service for separation from IFR flights and traffic information on other VFR flights.
Class D: IFR and VFR flights are permitted and all flights are provided with an ATC service. IFR flights are separated from other IFR flights and are provided with traffic information on all VFR flights. VFR flights are provided with traffic information on all other flights. All flights are separated during take-off and landing.
Class E: IFR and VFR flights are permitted. IFR flights are provided with an ATC service and are separated from other IFR flights and receive traffic information on VFR flights as far as is practicable. VFR flights are provided with a flight information service, which includes traffic information, as far as is practicable.
Class F: IFR and VFR flights are permitted. All participating IFR flights receive an air traffic advisory service and all flights receive a flight information service if requested. This class is not used at present in Australian-administered airspace.
Class G: IFR and VFR flights are permitted. IFR and VFR flights receive a flight information service. North of 65°S this flight information service includes directed traffic information to IFR flights on other IFR flights and known VFR flights.
11 Under the Airspace Act 2007, CASA is responsible for determining when and how these classifications are to be deployed in Australian-administered airspace. CASA is to publish any changes to the airspace classes and corresponding information through the Federal Register of Legislative Instruments (FRLI) and then through the Australian AIP in a timely and accurate manner.
12 Pursuant to regulations made under section 11 of the Airspace Act 2007, CASA is responsible for the classification and designation of all Australian-administered airspace.
13 CASA has sole responsibility for the regulation of the design of all Australian-administered airspace.
Prohibited, Restricted and Danger Areas
14 Australia has adopted the ICAO designations described in Annex 15, Chapter 2, of the Chicago Convention for accommodating activities that may be incompatible with routine flying operations, i.e. Prohibited, Restricted and Danger Areas. These areas and the circumstances in which they can be declared are described at Regulation 6 of the Airspace Regulations 2007. This is consistent with the relevant ICAO documentation.
15 The declaration of these areas and the circumstances in which they can be declared are as follows:
Prohibited Area – CASA must not declare an area to be a Prohibited Area unless, in the opinion of CASA, it is necessary for reasons of military necessity to prohibit the flight of aircraft over the area.
Restricted Area – CASA must not declare an area to be a Restricted Area unless, in the opinion of CASA, it is necessary in the interests of public safety or the protection of the environment to restrict the flight of aircraft over the area to aircraft flown in accordance with specified conditions.
Danger Area – CASA must not declare an area to be a Danger Area unless, in the opinion of CASA, there exists within or over the area an activity that is a potential danger to aircraft flying over the area.
Process for Changing the Classification of a Volume of Airspace at an Aerodrome
16 To help determine when changes to airspace classification may be required in the airspace immediately around an aerodrome, (referred to as the control zone at a controlled aerodrome) the following criteria will be used: annual passenger transport operations (PTO) aircraft movements, the annual number of passengers and total annual aircraft movements (see Table 1).
Table 1. Airspace Criteria Thresholds
Class B
Class C
Class D
Service provided
ATC
ATC
ATC
Total annual aircraft movements
750,000
400,000
80,000
Total annual PTO aircraft movements
250,000
30,000
15,000
Total annual PTO passengers
25 million
1million
350,000
Process for Applying the Criteria
17 The criteria will take effect on 1 July 2012.
18 When annual traffic levels at an aerodrome meet a threshold of any one of the criteria CASA should complete an aeronautical risk review in consultation with the public, industry and other government agencies, subject to the requirements of Paragraph 24.
19 CASA will then make a determination to change the classification of airspace if necessary.
20 If annual traffic levels at an aerodrome fall below all three thresholds for its current classification, CASA should complete a similar risk review to determine whether a lower classification of airspace is appropriate, subject to the requirements of Paragraph 24.
21 If CASA has completed an aeronautical risk review in the previous year then it may choose to update that existing review if an aerodrome were to meet or fall below the threshold levels in the following year.
22 While the criteria provide a good indicator of likely airspace classification, CASA will be able to consider public, industry and agency comments, forecast future traffic levels and any significant risk mitigators already in place or planned at the location, before finalising an airspace determination.
23 This process will be undertaken by CASA in close consultation with Airservices, given that agency’s responsibility for the introduction of new or changed air traffic services and facilities arising from such CASA determinations.
24 Notwithstanding the above, these criteria do not preclude CASA examining the requirement for airspace changes at other aerodrome locations should CASA consider such examination is required, for example, on risk or safety grounds.
Process for Changing the Class or Designation of a Volume of Airspace
25 CASA’s risk review process should be consistent with published Australian Standards for risk management as updated.
26 The process for change will commence with CASA identifying the volumes of airspace it will be reviewing in accordance with Section 13 of the Airspace Act 2007.
27 The review process will then lead to the completion of a risk assessment of the particular volume of airspace under review.
28 The risk assessment should take into account the types of aircraft involved, the density of air traffic, the meteorological conditions, and such other factors as may be relevant.
29 On completion of the risk assessment process, CASA shall outline its proposals on the overall safety requirement for a particular airspace classification or designation.
30 These proposals will be to (a) change the classification or designation of airspace, (b) not change a classification or designation, but make other proposals to improve airspace arrangements, or (c) recommend a continuation of current airspace arrangements without any other proposals.
31 CASA will provide these proposals for public comment and, after considering these comments, make a determination to be implemented as directed by CASA, by the relevant parties.
32 Following a decision to change the class of a volume of airspace (a determination), that change must be formalised as a legislative instrument, endorsed by the airspace delegate, and published on FRLI. After a change has been registered on the FRLI, it can then take effect on, or after, the day on which the determination is published in the AIP or when notified by a Notice to Airmen (NOTAM). Designations of Prohibited, Restricted and Danger Areas may be published in the AIP or notified by a NOTAM subject to the requirements of the Airspace Regulations 2007.
33 There may be times when urgent decisions are required to meet a safety imperative and it may not be practicable to comply with parts of this process.