SAFA Skysailor Magazine

26 SKY SAILOR November | December 2019 What is airspace? “Airspace is the portion of the atmosphere con- trolled by a country above its territory, including its territorial waters.” (Wikipedia) The concept of controlled Airspace began between WW1 and WW2 when aviation started running scheduled services – these services needed ‘corridors’ to fly within, and radio com- munication and coordination started to become standard operating procedure. During WW2 radar was developed, adding to the systematic control of aircraft movements. At first, various systems of airspace control developed around the world, making it difficult for intercontinental flights that had to fly within one system in one country and then change to another system in the next. In 1990, ICAO (International Civil Aviation Organisation) adopted the current airspace scheme Sometimes called ‘alphabet airspace’. It divides airspace into seven classes. The USA adopted a slightly modified ICAO airspace system in 1993, with Australia following soon after, the UK used ICAO airspace, but also adopted the US/Australian system in 2014. Essentially Australian Airspace is as follows: ➲ ➲ Class A is used above FL 180 along the populated coastal areas, and above FL 245 elsewhere. ➲ ➲ Class B is not used. ➲ ➲ Class C is used in a 360° funnel shape in the Terminal Control Zones of the major interna- tional airports, extending up to the base of the Class A, generally at FL 180 over these airports. It also overlays Class D airspace at smaller airports. ➲ ➲ Class D is used for the Terminal Control Zones of medium-sized airports, extending from the surface up to 2,500ft (760m) AGL (depicted in MSL on a chart). Above this, Class C airspace is used, although generally only in a sector, and not 360° around the airport. ➲ ➲ Class E is used along the populated coastal areas, from 8,500ft (2,590m) to the base of the overlying Class A or Class C airspace. ➲ ➲ Class F is not used. ➲ ➲ Class G is used wherever other classes are not—almost always from the surface to the base of the overlying Class A, C, D or E airspace. Diagram 1 gives a good visual representation of how airspace works in Australia. Class C airspace goes right down to the ground at major airports – eg: Sydney airport, Brisbane airport, etc. About 16 or so kilometres out from the airport, Class C airspace’s lower limit is raised to something like 1500ft. Further out from the major airport the lower limit is raised (as per the diagram) to 8500ft. The upper limit is where Class C airspace meets Class A airspace at 18000ft. Quite often there will be a secondary airport near the major airport – eg: Parafield, Archerfield, Moorabbin, Jandakot, etc. The airspace around these airports is classified Class D controlled airspace. Class E airspace is used as ‘mid-level enroute controlled airspace’ and is open to both IFR and VFR aircraft. Class F airspace is not used in Australia. Class G airspace is uncontrolled airspace – it is airspace that is not controlled airspace. Where can we fly in airspace? The Civil Aviation Orders we fly under (CAO 95.8, 95.10 and 95.32) limit us to uncontrolled airspace – i.e: Class G airspace and Class E if we have VHF radios. Also, there are a few sites where SAFA clubs have applied to CASA for an exemption to fly from certain sites within controlled airspace – but this took considerable negotiation. There are also some areas within uncontrolled airspace where we cannot fly or we can fly only after meeting certain procedures ➲ ➲ Prohibited area – Airspace within which the flight of aircraft is prohibited. ➲ ➲ Restricted areas – Airspace within which the flight of aircraft is restricted in accordance with specified conditions. ➲ ➲ Danger areas – Airspace within which activities dangerous to the flight of aircraft may exist at specified times. These (PRD) areas are marked on aviation charts and are described in the AIP. Where can we find information about airspace? Essentially, there are two ways. The quick, easy way to get all the documenta- tion, maps, resources, etc., is to use one of the apps written for iPad/tablet use by general aviation pilots for flight planning and in-flight navigation. These apps are tailored for powered aircraft and So how good is Airspace? Some of the feedback we received from the VHF training courses is that many pilots feel a bit hazy about airspace. That’s understandable – we touch on it briefly in initial training, and again when a pilot works up to the higher ratings, but if you fly at low altitudes, at the same few sites, and you are familiar with the boundaries of your local flying area, then it’s possible a pilot hasn’t had much reason to review how airspace works. by Peter Allen, SAFA Projects Officer Class Controlled IFR VFR ATC Clearance Separation Traffic information A Controlled Yes No Required Provided for all flights N/A C Controlled Yes Yes Required Provided for all IFR/SVFR Provided for all VFR to IFR/SVFR/VFR D Controlled Yes Yes Required Provided for IFR Provided for all IFR and VFR E Controlled Yes Yes Required for IFR and SVFR Provided for IFR/SVFR Provided for all IFR and VFR to other IFR/SVFR flights where possible G Uncontrolled Yes Yes Not provided Not provided Provided where possible if requested Diagram 1