ERSA is a shortcut for --->'En-Route Supplement Australia'.
The En-Route Supplement Australia (ERSA) is a publication that is produced by the Australian Aviation Authority (CASA) and is used to provide pilots with information about the operation of airspace in Australia. The ERSA contains information about air traffic control procedures, communication frequencies, navigation aids, and other information that is relevant to the operation of aircraft within Australian airspace.
The ERSA is divided into a number of sections, each of which covers a specific region or area of Australia. Within each section, the ERSA provides detailed information about the specific airspace, navigation aids, and other features that are relevant to the operation of aircraft within that region.
For example, the ERSA might contain information about the location and operating characteristics of specific navigation aids, such as VOR (Very High Frequency Omnidirectional Range) stations, DME (Distance Measuring Equipment) stations, and ILS (Instrument Landing System) facilities. The ERSA might also contain information about the availability and location of air traffic control services, such as air traffic control centers and flight service stations.