Hi all
There is a table of VOLMET stations in AIP GEN 3.3 para 7.
How do we determine which stations would be available to an aircraft at a particular location and altitude?
There is one HF station listed in the table, at Alice Springs. Presumably this transmission can be heard everywhere in Australia?
The other stations listed in the table are VHF. Some of them are at recognisable locations (eg Mount Isa) so we could get out the map, measure the distance from aircraft to station, and compare that the theoretical formula for VHF range. However, some of the VHF stations are at locations that I don't recognise (like 'Bellenden Ker').
Alternatively we could search the ERC L charts for the green boxes that identify the ATS frequency and station sites. For example there's an area close to Cairns that is served by 'BN CEN Bellenden Ker'. Presumably the VOLMET station at Bellenden Ker has at least the range that is covered by this ATS service. But it can probably reach further.
Is there an 'official' way to select which stations are applicable?
I think I've got the answer to this (in case anyone else is looking!)
Until recently, VOLMET was a single HF frequency from a transmitter based at Alice Springs, transmitting a message on the hour and half-hour, while AERIS was a network of VHF stations around the country, transmitting continuously.
However, the latest AIP (November 2023) states, in the list of "significant changes" at the front, that AERIS has been removed "in line with the requirements of ICAO Annex 3" and subsumed into VOLMET.
Apparently, AERIS was an Australian thing and we are now trying to conform to ICAO more closely.
The table in AIP GEN 3.5 para 7 now contains both the old VOLMET station (HF) and the former AERIS stations (VHF) under the heading of VOLMET.
Some of the practice test questions (as of February 2024) ask for VOLMET information, and these appear to be out-of-date, since the "correct" answer given is always the HF station information, even if the question indicates that you're very close to one of the former AERIS stations.
Hope that helps someone!
