How does CASA and Air Services decide whether an airport has a Control Tower?

[Rosso Noche]

Hi Everyone,

Quick question:

How does CASA and Air Services Australia decide if an airport gets a control tower?

I am doing a uni assignment and I am looking for a reference regarding this. I thought there was some threshold based on aircraft capacity and/or frequency of movements however I am unable to find a reference in any of the reg's, MOS or supporting documentation.

Any assistance or information to point me in the right direction would be greatly appreciated.

Cheers, Rosso.

[BEVLY9]

"Enhanced air traffic services at regional airports

After consultation with other aviation agencies and industry, Airservices defined the implementation plan for improving air traffic service arrangements at a number of major regional airports.

Priority was given to regional airports that show a predicted growth in traffic levels, which have existing surveillance infrastructure that is of suitable quality to provide the approach services. During the review, the surveillance methods considered included the use of new and existing technologies that were developed over recent years, these include Automatic Dependant Surveillance Broadcast (ADS-B) and Wide Area Multilateration (WAM).

The plan outlines a phased approach to the introduction of Regional Approach Services (RAPPS) using surveillance, initially focusing on seven locations, namely Hobart, Launceston, Rockhampton, Mackay, the Sunshine Coast and Alice Springs. Other airports listed in the mandate will be reviewed periodically to determine if the traffic density warrants the need for SAFRA-type services."


found this is the airservices website. not exactly about towers but gives an small indication of their process.

[QSK?]

Rosso

In years gone by, DCA/CAA used to rely on simple aircraft movement and traffic mix critieria to determine whether a control tower (or a flight service unit) was required or not e.g. total number of aircraft movement per annum, number of RPT movements pa, percentage of IFR vs VFR movements etc. These movement considerations were then overlaid with a subjective assessment of environmental factors that could impact on safety e.g. presence of terrain, adverse weather effects, complexity of surrounding airspace etc. It should be noted that there were also traffic movement criteria for discontinuing a control tower or a flight service unit.

In subsequent years, this simple establishment/discontinuance process matured to include basic collision risk modelling and societal impact modelling to determine the impacts of not only implementing a control tower but understanding the potential consequences of not establishing a tower. Proposed changes were also subject to a cost benefit assessment to ensure (safety and efficiency) benefits outweighed the cost of any new service. My recollection is that all ATS units were eventually subject to regular review but I can't recall the timing.

My understanding of the process today is that CASA now uses the aircraft movement data as a simple "trigger criteria" i.e.to determine whether a more detailed and comprehensive aeronautical study is required to support changes to airspace classifications or the air traffic service to be provided (e.g. CTAF (R), Unicom, CA/GRS or control tower). The aeronautical study conducted by CASA will establish the level of risk at an airport after consideration of all the factors listed above and make a recommendation as to the appropriate airspace classification and/or air traffic service to be provided at the airport to reduce perceived risk to acceptable levels. CASA's recommendations are then reflected in an airspace change proposal that is subject to a CBA and consultation with industry stakeholders before implementation.

Once coordinated and approved, the changed arrangements are implemented. My understanding is that CASA formally reviews the risk profile at certified airports at 5 year intervals.

Quite happy for others to correct me if my understanding of the process is incorrect as it has been some time since my involvement in such matters. But it might also be useful for you to ring CASA and ask to speak to someone in the Office of Airspace Regulation who will certainly be able to give you guidance on the correct process.

[CaptainMidnight]

CASA is the airspace and aviation safety regulator. It is they who make the legal determination what level of air traffic service is required in an area or at and in the vicinity of an aerodrome. They do that by conducting aeronautical studies, the outcome of which determines what if any action is required.

Airservices is the civil airspace air traffic service provider, and they provide the services that CASA deem necessary.

Suggest you contact CASA's Office of Airspace Regulation:

[email protected]

https://www.casa.gov.au/airspace/landing-page/airspace-regulation

[OZBUSDRIVER]

Just plug those key words into Google and see what you dig up. You may have to go in maybe a dozen pages worth but you will find the formula. It is solely based on annual pax movements. Not only tower services but also Rescue Fire Fighter Services (RFFS). Ballina is on the cusp of requiring a service whilst Avalon may lose theirs. Research Lad! Learn something by looking:)

[Green on, Go!]

In addition to what CaptainMidnight said, from the CASA OAR page, have a look at the recent supplementary airspace review of Gladstone, along with the two prior Gladstone airspace reviews to see this decision-making in practice.

[Dick Smith]

Before my time all jet airline aircraft had to operate with a control tower.

That's why the multimillion dollar tower was built at Gove.

I stopped this ridiculous mis allocation of resources and our Board agreed to use the FAA establishment and discontinuance formulae.

This resulted in the closing of towers like Mt Isa and many others . The Gove Tower has never been used. Can someone post a photo- does it still have a fake goldfish hanging from the ceiling?

Since my time Peter Cromarty introduced a new system which I would imagine keeps the status quo.

When I have influence again we will continue with the cost reductions including opening the towers up to competition. The ATCs told me they wanted to set up there own business that could halve the cost of D towers.

In the USA about half the towers are run under contract with major cost savings.

Not really necessary in Aus with the ex military running our aviation system because the airlines don't seem to worry about the rip off costs.

[Dick Smith]

By the way, is Kim Jones still involved in airspace? In my time he seemed to do everything to support the existing system and undermine my cost saving reforms.

Perhaps Kim could come on and advise if he has changed his views now that GA is almost destroyed?

Of course. If I am incorrect and Kim supports cost saving I will readily apologise and become his greatest supporter.

[fujii]

When I have influence again........

Is this a thought bubble or are you actually planning something?

[Dick Smith]

Surely it's clear that in another five years or so our aviation industry will be so destroyed they would even accept the devil to do something to make a fix .

[swh]

Just plug those key words into Google and see what you dig up. You may have to go in maybe a dozen pages worth but you will find the formula.

isnt just

P{tower}=1/(Distance from Canberra)^2

:confused::confused::confused:

[mgahan]

Dick,

An associate and I recently had an exchange with Kim Jones which resulted in his providing support for a potentially major change in one of the ICAO SARPS. Based on that support and positive words from others I self funded travel to Montreal earlier this month to meet with one of the AN14 WGs.

In my earlier life in CAA and AsA and some later interactions with CASA, I always found Kim willing to listen to and assess change proposals based on their merit. Perhaps that is where your problem lies.

MJG

[Dick Smith]

So what is his position?

And what is the change? Will it save money for our industry- especially GA ?

[Rosso Noche]

Thank you everyone for the detailed replies and for taking the time to respond, it is appreciated.


Just plug those key words into Google and see what you dig up. ... Research Lad! Learn something by looking:)

Damn, you caught me. Google, why didn't I think of that? And here I was hoping I could get my degree via PPRUNE!

Thanks for your insight OZBUSDRIVER. There's always one. :ugh:

[Traffic_Is_Er_Was]

As an aside, the TWR at Gove was built to a standard design and assembled on site. The internal cabin fitout was never fully completed. The console etc is probably still in there, as it would have been assembled in situ and wouldn't fit down the stairs. The TWR was prefabricated, but could not be economically defabricated. In my later capacity with the airport operator, we approached many potential users, but in the end, we basically couldn't give it away, even as scrap, as transport costs ex Gove were too high. Initially the overlying ATC VHF and UHF radio gear were in its equipment room, but they were eventually transferred to the Satellite Comms site, and Airservices then pretty much gave all their no longer required buildings to the local council. Myself and another bloke stripped all the racks and wiring out of the equipment rooms of the TWR and FSU and the space was let as offices to charter operators.

[LeadSled]

Rosso,
The actual answer is: It is all in the CASR/ MOS, establishment and disestablishment criteria etc.
With--- as we know, huge disconnects, giving us fire services (economic waste in classical economics ) at Ballina, but not even a Unicom (by whatever name you want to call it) or even the unique Australian bastardisation, CAGRO.
Tootle pip!!

[Stationair8]

So what about Dubbo, Broken Hill etc go when Ansett NSW operated the F-28's in NSW during the early 1970's?

Did DCA hand out a dispensation for no ATC or was the F-28 below a certain weight?

Did Broken Hill have a RFFS in those days?

The old flight service unit and briefing office were located behind the terminal building from memory.

[Rosso Noche]

Thanks for the info Leadsled.

Unfortunately I cannot find anything in the CASR's or MOS about establishment and disestablishment criteria relating specifically to the determination of whether an Airport will be ATC controlled or not.

It refers to ARFF which is straight forward - the category determined by ICAO guidelines in the ICAO Airport Services manual and Cat 6 and above in Australia supplied with the service through ASA. I thought a similar clear cut process would be in place for a deciding if a tower service was required and was my original motivation for the post as I couldn't find a reference similar to the ARFF criteria. It appears the process may be a little more subjective (and contentious) given some of the examples listed in this and other similar threads on the issue.

I have reworded my work and referenced the Airspace Regulation 2007. It was the closest thing I could find given the context of the paper.

Thanks again for the replies. It is appreciated.

[Rosso Noche]

In addition to what CaptainMidnight said, from the CASA OAR page, have a look at the recent supplementary airspace review of Gladstone, along with the two prior Gladstone airspace reviews to see this decision-making in practice.

Thanks for the heads up on the Gladestone review Green on, go. It certainly makes for some interesting and insightful reading.

[topdrop]

F28 to Broken Hill was in the 80s - no ARFF. FSU was about 150 metres from terminal, consoles faced away from runway - great decision, not. Jet RPT required approval to operate outside CTA (OCTA for younger pruners). I think Gove was the only place that had approval for DC9 to operate without ATC.

[Traffic_Is_Er_Was]

Gove was also for a time the only place both mainlines of the day operated B737's into as RPT without a TWR. They also operated into Ayers Rock but they were classed as CHTR, so fell outside the regs. It was the potential for two 73's to be mixing it up with the local GA that drove the building of the TWR. While the apron could fit two at a pinch, the schedules had them separated, but often they were arriving and departing traffic for each other. It used to make me chuckle that while they would happily be spat out of the overlying CTA on descent, and left to work things out under "Directed Traffic", coordinating a pre departure clearance with DRW ATC involved much more to-ing and fro-ing so that they would be adequately separated prior to reaching CTA on climb (which I think was either at FL200 or FL250 from distant memory).
Edit: also no fire service. Response was two full time and a few volunteer town Firies in civil pumpers who couldn't physically arrive any sooner than 15-20 mins minimum after callout. The nearby mine site also provided a unit, but all would have been p#ssing in the wind if ever really needed.

[OZBUSDRIVER]

The Air Services Act 1995, Division 2, Section 8 states that Airservices Australia will provide rescue and fire fighting services, or provide those services under contract. The Airports Act 1996, Part 14, Section 216 states that an entity other than Airservices Australia can provide rescue and fire fighting services with an arrangement approved in writing by the Minister for Transport and Regional Services.

Currently, there are no civil aviation safety regulations in Australia that cover the services provided by Airservices Australia. These services include air traffic, aerodrome rescue and fire fighting, aeronautical telecommunications, radio navigation, and training and licensing for air traffic controllers and aerodrome fire-fighters.

The Government has acknowledged this gap in safety regulation by directing CASA to develop an appropriate safety regulatory framework for these services. These new safety regulations address this direction by the Government.
AustLi (http://www.austlii.edu.au/au/legis/cth/num_reg_es/caar200222002n167397.html)
The view in 2007

The proposed criteria for the establishment of Class D services is 80000 annual aircraft movements or 15000 annual PTO aircraft movements or 300000 annual PTO passengers.

The final determination is scheduled to be published in the second half of 2011 with an implementation date of 1 January 2012. If a location exceeds the criteria it only triggers an inquiry by CASA and does not necessary follow that a change of airspace will occur. CivilAir contend that AirservicesAustralia is currently having problems staffing for it's current requirements. To have take on extra obligations will further stretch resources.

CivilAir (http://civilair.asn.au/index.php?option=com_content&view=article&id=1542:is-atc-really-coming-to-a-town-near-you&catid=1&Itemid=1)

The shame of it is the link on the CivilAir site to the Department is incorrect

Then again...maybe opinion is better than attribution. You after data or gossip, Rosso Noche?

[Advance]

Going back to the original question at the time when Gove tower was built the answer is:
Airservices and CASA were part of one organisation at the time - though you would not have known it - the people involved in Flight Standards and those involved in Air Traffic Control did not bother to communicate.
The Flight Standards people who, as a regular contributor to this site will tell you, were almost all ex-military with no understanding of costs or business rationale, dictated that all RPT jet operations had to be under the watchful eye of a control tower.
So it was decreed a tower be built at Gove, regardless of expense (cyclone design standards etc).
The Airways Division at the time was run by an engineer who thought such things were personal memorials to his achievements.
The ATC folk who had to meet a budget and had to co-ordinate their work with the airlines refused to staff the tower and incredibly the Board at the time backed this decision.

Result a huge white elephant.

Nowadays there is meant to be a more logical process overseen by the Office of Airspace Regulation within CASA but it is proving itself a dud in other ways.

Gee, I'd like to name names but I might even now get sued!

[Roger Gove]

Traffic,
Gove was capable of parking a B737 and BA146 on the pax hardstand.
Have seen 2 x B737, 1 x BA146, 1 x F28 (Departmental) and 2 x DC3 on the ground simultaneously.
F28 was parked on the gravel as were the 2 x DC3.
Gove was the only OCTA aerodrome allowed to have Medium jet operations.
The tower was built primarily as an end result of the DC9 diversion to Groote Eylandt.
The rationale was; Gove needs an ILS (for the one day of the year when the heavy rain coincides with the jet arrival) - oh Toyota, we can't have an ILS at a non-controlled aerodrome!
Tower was built on a mound to get the required cab height without needing a lift for the staff. There were also 3 houses built for the ATC who refused to man the place.
The Gove Tower saga was a WODFU (Well Organised DCA ....) from the start.
Finally sense prevailed in SA/NT Regional Office and the thing was never commissioned.
At one stage the RAAF was approached to airlift the tower to Ayers Rock.
Roger Gove.

[Checklist Charlie]

Gove was the only OCTA aerodrome allowed to have Medium jet operations.
Not forgetting Port Hedland had DC9's through there as well.

CC

[Lead Balloon]

In case you’re still around, Rosso Noche, the short answer to your question is: politics.

[Advance]

Nothing to do with the SA/NT office of the old Department of Name Changes - this whole fiasco was run by the true experts at foul ups in Canberra.

[Traffic_Is_Er_Was]

Gove was capable of parking a B737 and BA146 on the pax hardstand.
Was capable of 2 x B737 on the original hard stand. Wouldn't think you'd have got a BAe146 on there as well. Was it parked on the hardstand in front of the Aeromed hangar? With the normal parking position parallel to the runway, the tail of a B737 extended through the OLS. With 2 on the alternate positions, the tail of the second one was even worse. They also blocked both main taxiways while parked. There was a hydrant pit located in the dirt in front of the "terminal", so we extended the hardstand (and built a wider taxiway to service it - the original 2 were not to code) to incorporate it so that one of the jets (BAe146/F28 by then) could park closer to the terminal and use it, which became the prime position until the new Terminal and hardstand was constructed.
There were also 3 houses built for the ATC who refused to man the place.
ATC were lining up to man the place. Why wouldn't they? No traffic to speak off, and think of the lifestyle. The TWR project was shut down before they could transfer over.
I found some photos the other day of both the RAAF's BAC-111s parked on the dirt. Noisy buggers! Because of the need to keep the sealed apron free for the RPT jets, just about all other parking was on the dirt.

[topdrop]

A new Regional Director was appointed to SA/NT region, who balked at the cost of manning Gove Tower. He cancelled it. The Tower was not yet fitted out, though I think some of the console was downstairs.
Flight Service staff took over the houses built for ATC - 3 has been mentioned but I thought it was more than that. They also hung a huge papier mache goldfish from the ceiling of the Tower - resulted in quite a few comments from pilots.

[Traffic_Is_Er_Was]

The carcass of the console was up in the cabin. It hadn't had any fit out done to it. I reckon there wasn't that much left to do on the Tower and equipment rooms, except for finishing the cabin fit out.
When I got there (in '87), the Radio Tech had one of the houses and the FS OIC and one FSO had one each. I think there may have been 5 or 6 built all up. The Met OIC had one also I seem to remember, maybe one or two of the other Met guys might have had the others, I can't remember. All the Departmental houses (except for the Met ones) were sold to locals when the FSU was closed. The staff got first option, but none of us took it up.
I remember being told the panes of glass making up the cab windows were something like $10000 each installed. There were 12. The signal lamp was still hanging from the roof last time I was in there, circa mid 2000. What was left of the goldfish was on the floor. The separate ground level equipment room was practically complete. Most of the ATC en-route radio and comms gear was installed, and stayed in use by Darwin ATC. It was relocated across to the other Airservices radio sites prior to them gifting the TWR site (and other surplus ex AsA buildings) over to the aerodrome operator.

[Roger Gove]

Traffic,
There were 6 houses built at Gove. 3 for ATC and 3 for BoM as part of the Gove Met Station which was on the opposite side of the runway to the FSU. The Met station was built as part of the Cyclone Monitoring system. It provided aerodrome met as a "sideline."
Flight Service did look at how the tower could be used for aerodrome and AFIZ traffic with briefing and the Groote frequency (FIS 2) remaining downstairs.
There wasn't enough room in the tower cabin for 2 operators, and besides we would have to do our own flight data!
Lots of possibilities were looked at.
Roy Sheppard was the OIC and he had one of the new houses.
Yes 2 x B737 and a BA146 on hte hardstand. The 146 was nose down the taxiway, 1 B737 pulled up tight behind it and the second B737 tail down the other taxiway.
It was an interesting place to work.
Roger

[Ex FSO GRIFFO]

The closest I ever got to Gove was knowing one 'RB' when he came to Derbs......
By the way, what was the goldfish all about?

Cheers

[Roger Gove]

Griffo,
Ah the life in the long lost western state!
The goldfish was created by one of the FSO's and hung from the Aldis Lamp because there was no other use for the tower cabin!
It did initially grow very good fungi and mold on everything because the aircondtioning was running but had not been set up properly.
Cost around $1k/month until it was shut down.
Many visiting pilots commented on the goldfish. Even to notifying FS when it had fallen down.
The Flight Service Unit had its resident Alsatian dog Tora who would be there at 0400 opening and featured on the closing check list to ensure he had been evicted for the night.
Roger Gove

[Bedder believeit]

When I first started in ATC in the late 60's, there was a gentleman in charge of DCA (Dept of Civil Aviation) by the name of Sir Donald George Anderson. At this moment I'm looking at my first pilot's licence and ATC licence signed by none other than Sir D.G. Anderson.
As far as to the question of who decided on the question of what were the criterior as to authorising establishment of control towers, it was Sir D.G.Anderson. When he said "jump..." well you know the rest
Hence when I grew up in Madang and learnt to fly in Lae, both had ATC towers.
In the early 70's when jets started to operate RPT services in Australia (F28's) the norm was ATC required.
Time moves on.

[Traffic_Is_Er_Was]

Roy Sheppard was the OIC
Roy was the boss when I got there to replace Ian Jennings.

[cogwheel]

Ex FSO GRIFFO (https://www.pprune.org/members/86703-ex-fso-griffo)


The closest I ever got to Gove was knowing one 'RB' when he came to Derbs......

when we’re you at DB? I was there 69-71. George Moyle was OIC who later went to JT.

[Mr Approach]

The question first put, has been answered I think - however if you read the airspace policy document closely you will see that the traffic and passenger movements only trigger a review.
CASA OAR reviews, because of their top down methodology, invariably find that the airspace "is fit for purpose". This occurred at Hobart but then Airservices decided it wanted Class C airspace so OAR had to go back and create a report agreeing with them. It also happenned at Port Hedland where the ATC Line Manager wanted to close the FISU, CASA OAR approved, but the Airservices CEO decided to keep it open. CASA OAR then found a discontinuance figure so low that the FISU can stay open forever. You will also note, If you read the airspace review of Avalon, that CASA OAR has now formally handed it's responsibility for airspace back to Airservices, by requiring them to come up with a plan instead of CASA, as per the legislation.

Airservices current "fad" is remote Tower technology, however this technology is far from being mature, hence Airservices procrastination about new Towers and replacing old ones. I have seen most of the Towers in Australia and can list all of the ones that are past their use by dates. These include Essendon, Hobart, Bankstown, Moorabbin, Parafield, Jandakot and Canberra but for a different reason. What is happenning, nothing as far as can be seen.

The opening of new Towers is even more vexed. There are flying schools popping up at uncontrolled airports all over the country, mostly these airports have regional air services as well so these aircraft are mixing it in the circuit with foreign students who have English as a second language! Unfortunately Airservices is not able to provide Tower service at a cost that is compatible with small aviation operations. You only have to look at what they build for a simple Fire Service to see the expense involved. The airspace around an airport should be considered an asset that can be utilised by the airport owners to leverage their plans for development. In the UK Southend wanted airline services so they built a control tower, and approach centre and installed ILS and radar. They then conducted ATC as a voluntary service in Class G airspace until the UK CAA allocated Class D airspace: that is the bottom up approach also used in the USA. However according to CASR Part 172 no-one can operate ATC or even train ATCs, unless they are the Federal Government, or have their permission. In Australia I could argue that we have to wait for an airport environment to become dangerous (that is exceed the MInister's guidelines) before we then have a "review" and then try and talk Airservices into providing it's grossly expensive ATC. Are we crazy - or what?

[Lead Balloon]

I’d say corrupted rather than crazy.

The move of OAR from Airservices to CASA was and remains a sham so typical of Australian aviation. That CASA (the supposed regulator) would blithely put in writing that it wants the regulated (Airservices) to make a recommendation to the regulator about Avalon airspace arrangements shows how corrupted the airspace designation system has become. The other examples given by Mr A would in other regulatory regimes be breathtaking, but in Australian aviation? Not so much any more.

You forgot to mention that the ATSB would not be prepared to say anything critical about the sham. And we know why.

The ‘dream team’ in action. Or maybe that should be ‘inaction’....

[Roger Gove]

Approach,
Isn't it called cost benefit analysis?
To return to the Gove Tower situation. The cost was enormous to cover a Ba146 and a B737 (sometimes 2) well spaced movements per day for 5 days per week.
And that was 1985.
The only incident I know of involving a medium jet at Gove was the DC9 diverting to Groote Eylandt after one too many VOR approaches.
CAA (remember them) policy at the time was medium jets needed CTA.
In the age of user pays cost shifting, the economics are rarely there for the establishment and continued operation of a Tower and the associated airspace steps.
The same could be applied to the provision of RFSS, given that a B737 or A320 requires CAT6 fire suppression capability for a limited number of movements per day.
Isn't the lack of a Tower part of the reason for establishing a flying school at a regional airport?
Are we crazy? - Maybe!
Roger Gove

[Mr Approach]

Hi Roger - I think you have nailed the Australian philosophy nicely! Did I say anything about control area steps?
You are correct about cost/benefit, but Gove was a rubbish decision based on outdated philosophies and should be taken out of this argument completely.

Safety miigation should be concentrated where it can have the most effect.
A simple control tower (Class D) with one controller is all that is needed to keep control of a circuit area and allow for RPT aircraft and other visitors to arrive and depart safely.
Ideally the surrounding airspace would be Class E, with surveillance, so that IFR aircraft can safely fly in cloud, under the hood.
When the aerodrome gets busier it begins to warrant a separate approach control (Class D or C) or one shared with the tower cab - this is much easier nowadays than it was when radars were dark room devices.
Only when an aerodrome starts to generate significant traffic on defined routes does extended Class C airspace become a necessity.
Class A should be confined to the upper airspace above for instance FL180.

So Ballina - a small single person Tower surrounded by Class E airspace, with surveillance, encompassing the RPT traffic routes in and out. At such a low RPT traffic airport, procedural Class C control area steps are a waste of airspace controller resources. This can be demonstrated at Karratha where a two person tower is required for seven hours a day.
If the single person tower at Ballina was staffed by the same people who operate the CA/GRS (All ex-ATCs) then costs would be commensurate with the operation.
This same model could be used at every airport in the country that conducts circuit training and has RPT movements. (Wellcamp where the locals do not want a Tower - or is it an Airservices tower they do not want?)

The key is to allow some market forces into the equation and get rid of this silly idea that only the Federal Government can be trusted to provide safe air traffic control.
I would have thought that idea would appeal to a free-enterprise country like Australia - or am I missing something?

[Traffic_Is_Er_Was]

The key is to allow some market forces into the equation and get rid of this silly idea that only the Federal Government can be trusted to provide safe air traffic control.

In just about every country in the world, the government in some shape or form provides ATC. There are private contract ATC in a lot of smaller towers in the USA, but even then the FAA has it's fingers pretty deep in that pie, ie it pays the contractor to provide ATC at that location on its behalf as long as the cost/benefits continue to stack up. If the FAA needs to save money, TWRs get closed. Not many (if any) municipalities take over running and manning them (if they are even allowed to) in the land of the free if the government stops paying. What makes you think local councils in Australia will? They do not even want to provide a UNICOM.

[Mr Approach]

You are correct Traffic, but the major difference is cost recovery, not cost/benefit.
The US and others are more concerned with providing the services where they are needed, and then working out how they can be provided at a reasonable cost.

The US does as you describe but does not pass on it's bureaucratic costs to the VFR towers, or insist on using Government employed ATCs. Hence over 60% of the VFR Towers are staffed by retired FAA ATCs on much lower wages than they were getting from the Government.
Canada has a not-for-profit Civil ATC organisation, so users know they are paying only what it costs to provide a service. Any windfall surplus is returned to industry.
The UK has about 160 ANSPs, all providing services in a contracted system where market forces operate. (Gatwick even employs a German company to provide it's Tower and Approach - but I'm not sure that will survive Brexit!)

Australia, on the other hand, has a Government-mandated cost recovery system. Government agencies such as Airservices and CASA are required to charge their customers to recover costs. Airservices charges by the weight of an aircraft, as if that had anything to do with the cost of providing ATC, and CASA charges $190 per hour, which is way beyond what they pay anybody.
Whether the Minister will admit to it or not, (and it is all under the Government's control) this type of regime, in order to fulfill the Government mandate, has to organise itself around where the most money can be extracted. In Airservices case this is over the oceans, the upper flight levels and major terminal areas. With CASA it means dumping all responsibility for GA onto 'self-managing" entities such as RAus and the Glider Federation, while concentrating on AOCs and the big end of aviation. (Yes - I know about the Chicago Convention)

Either the US or UK model would work fine in Australia and indeed, about 20 years ago, the Coalition started down that road of divesting Airservices (that is itself) of aerodrome ATC and Fire Services. There were many vested interests that stopped the process, however then air traffic at our non-controlled airports had not increased to current (non-COVID) levels so there was breathing space.
The mid-air at Mangalore is what, in the safety business, is called a leading indicator, or if you like a warning. Do nothing and it will inevitably happen again.

[Traffic_Is_Er_Was]

But Mangalore wasn't even busy at the time. It was 2 IFR light aircraft (who were told about each other) at an uncontrolled aerodrome. It could have happened at any uncontrolled aerodrome in Australia. What are you going to do, put TWRs at them all?

[Mr Approach]

No Traffic - In Australia, that would be a waste of resources.
However ICAO requires that instrument approaches are contained within controlled airspace - another Australian non-compliance. Here we require that they be contained in the same category of airspace, but, CASA hands out exemptions all over the place, particularly for NDB approaches.

A crazy example exists at Toowoomba where there is an RNaV approach that flies near Oakey. When the Army Tower is open it cannot be used!

In Europe an instrument approach can only be used when a tower is operating, that is the reason behind their push for remote Towers.
In the USA Class E airspace with a CTAF for VFR traffic is used. Whatever your views about Class E, ICAO considers it to be controlled airspace, so it meets the international criteria. The US system is far more applicable to Australia than the European.
So Class E, controlled from Melbourne Centre by en-route controllers, would have provided separation of the two IFR training aircraft. Instead the same Melbourne controllers with Class G have their work cut out, giving traffic information, listening to what the pilots do next, re-evaluating the traffic information and re-issuing it, and so on....
Believe me it is sometimes much easier to separate than provide ever changing traffic information. (PS. That is also why Class D Tower ATCs sometimes "over separate" VFR aircraft, it is quicker and easier than passing traffic information)
I hope that answers your question.