Nav aids in Aus to be shut down?
 

From another forum, a mate of mine in the Aus Navy wrote -

I haven't worked since 2009 but this is pretty big news, I've never heard anything about it.
How true is it?

He should stick to sailing boats. :ok:

Or, ask him what the definition of "near future" is. Perhaps it is the same timeframe for getting all 6 Collins class tubs up to speed and fully operational!

I believe mainly enroute navaids will go with a reduction of aids at airdromes. E.G IRS/GPS Enroute + Approach with ILS or VOR depending on the usage at that Airdrome as a backup. With all NDB's phased out.
This will probably mean the end of circling approaches.

Have Fun
I Do
:)

Incorrect.

Most navaids are part of an essential network for air traffic management by ATC, and those have been (or will be) upgraded or replaced when they reach end of life. Others not essential to the network have either been offered to local aerodrome owners or operators to take over, or been decommissioned if the aerodrome owner or operators have said they do not require them, or are currently being maintained until someone makes a decision.

Your mate should join an aviation industry association such as RAAA AOPA or participate in local RAPAC.

As someone who works for the organisation in question....I can tell you that they plan to decomission 170 navaids Australia wide within the next 3 yrs, and this does include navaids at major/international aerodromes. For example I am pretty sure that the VOR's at SY and ML are on the list.

Those NAVAIDS that are to be kept in the backup infrastructure are currently being replaced. If a navaid near you is not scheduled to be replaced then there is a good chance it is being decomissioned.

So to answer all the "negative" comments

Quite incorrect, navaids are no longer an essential network for traffic management. It is cheaper and easier to replace a navaid with a waypoint. The only organisation/s in the country that is permitted to operate navaids is AsA and RAAF. So they are not being offered to aerodromes or private consortiums because they don't have the approvals to operate them.

Not all NDB's phased out, some of them are part of the backup navaid network and are currently being replaced/upgraded. If you do find the list, you will quite surprised as to which navaids are on it

I would say that in 3-5 years ground based navaids will be far and few between. Well thats the info they have provided to us for approach planning requirements.

Alpha

Also forgot to add....

The reason the Navy know about this is because they can/do use some of the coastal NDB's for navigation. All of the coastal NDB's are published on the nautical charts and they use them as a cross check for navigation....well they did when I worked for them.

Thanks AlphaC.
I can see how for modern airliners it's not a problem but for blokes out in the bush it'd be a heck of a change.

NDB's mainly are the species being culled.

This 'process' has been going on for over 20 years or so now.

For example, how long is it since the 'non-essential' Perth NDB at Pt Waylen, Attadale / Alfred Cove, was decommissioned due to it being deemed 'uneconomic' / 'non-essential'..?

This NDB had a 'terrific' range out over the Indian Ocean, with some of the 'Springbok' and Qantas crews reporting it at a 'looong waaay' out, at times...
No GPS then......

Anybody remember it? Used to use it??

There must be many more such examples.

Similarly, there used to be a Marine NDB at Cape Leeuwin, which some pilots who knew about it, used to......

Dems were de days.....:}

The loss of 'domestic' NDB's will be sad loss for the G/A guys, especially at 'remote locations' in de middle of de night....:eek:

would this mean a huge change in all the navigation syllabuses? Since the PPL & CPL navigations have a huge focus on the nav-aids.

Yeah. CASA will probably update the exams to include LORAN. :E

Where does that leave TSO-C129 (non-WAAS) GPS's which require an alternate with a ground based aid ?

A ploy to have everyone change over to WAAS GPS's which are unable to receive the WAAS signals here is Oz, just to not need an alternate without a ground based aid?

Perhaps you should talk to your ATS systems people alphacentauri because the information to Industry comes from them. They also indicated that some navaids are required for air traffic management outside surveillance coverage, due not all aircraft being equipped with GPS-based navigation systems.

ASA and Defence are not the only two "permited" to operate NAVAIDS. Quite a number of NDBs are privately operated - Renmark and Shepparton are just two that come to mind - and they have been offered to aerodrome operators for some time.

The last we heard about the SY VOR was it was to be shut down for a period while new hangars are being built, and after to be reinstated.

Folks,
Not limited to NDB, there is at least one, probably one more ILS "privately" owned and operated, there is no law that prevents an "interested party" owning and operating navaids, provided compliance witha bleeding thick book of standards is shown.
In a similar vein, there are quite a few "privately owned" approach and departure procedures that are not published and available for other users.
Tootle pip!!

Interestingly this may have ramifications for some of the smaller operators of medium jets (early A320's and 737 Classics), as most of those are not GPS-equipped, and (I'm told) are not a simple process to retrofit. Admittedly this is only a small number of aircraft, but would limit a few operators.

The Norfolk NDB is one of the strongest I know, and at night can be received with a strong ident and bearing from west of Coffs Harbour.

Anyone wishing to find the list of backup network naiads, look on the CASA website and find reference to a NPRM1105AS for aircraft equipage. Annex G gives a list of the navaids which will be kept after the mandate date of Feb 2016.
This list was put together by ASTRA. Look this up too; it is a consultative body made up of various members of the aviation fraternity, including QANTAS, Virgin, AOPA, RAAA etc. This body reports to the APG which is basically a coffee club of the CEO's of AsA, CASA, DoIT and Defence. APG recommends to the Ministers of Defence and Transport.
The list was formulated in 2005 and has been accepted by all these bodies. The reasoning behind the list: it is a backup in case of GPS failure and is supposed to provide guidance to the nearest suitable aerodrome - note most suitable and not preferred aerodrome. Currently there are approximately 410 non precision aids (NDB, VOR, DME). There are about 220 on the backup list. The declared position of both CASA and Airservices is that there will be a reduction to the backup network after the mandate kicks in in Feb 2016. This is easily determined by looking at published 5 and 10 year plans on the various websites.
AsA has been decommissioning aids since the 1990's on a site by site determined basis. There are a large number of aids which were commissioned in the 60's and 70's which have either outlived their original purpose or have become difficult to maintain - spares, structures, electronics, suppliers, any number of reasons. This will continue to occur. There are sites under scrutiny now as anyone who has attended a recent RAPAC can attest.
The bare facts are that it costs around 600K to replace an NDB and around 1.2mill to replace a VOR. A DME not so much because the antenna and electronic setups are simpler. The big players in aviation are not prepared to pay for this replacement in the long run when they are equipping to run GNSS nav system. ASTRA was told in 2005 that to replace the ground based nav system outside of the backup network would cost between 140 and 200 million dollars. You can do the sums for the current cost.

Leadsled

Not quite. Airservices is the only holder of a civil CASR Part 171 certificate in Australia. All privately owned aids are maintained under contract by Airservices staff. Privately owned aids are installed and commissioned under that 171 certificate.

CaptainMidnight

As the only holder of the CASR 171 certificate, AsA is the only civilian organisation permitted to operate navaids. They can be owned by anybody, but they can only be operated under the 171 certificate. The aerodromes can buy them, but the only way they can be operated is under contract with AsA....which is going to cost the aerodromes more money.

As far as I know the SY VOR is scheduled to be decommissioned. I have not heard of any plans to re-instate it...but that doesn't mean it won't happen.

Alpha

GPS is run and controlled by the US military. It can be downgraded or even switched off. It can remain on but coded for military use only.

Removing ground based aids before there is a back up system is a recipe for trouble.

Lat-seps
 

So for those of us that work in non-radar towers doing procedural approach, does that mean we'll finally get decent lat sep drawings based on real GPS tolerences and actually be able to use GPS/RNAV equipped aircraft properly?

:D:D:D:D:):):D:D:D

Disregard.....

They are on their way. I've seen the drafts. Useable, but VOR tolerances are much better..

They're still using the 727 for ATPL flight planning and performance and loading exams! LOL!

BTW, I thought some modern airliners use enroute Nav Aids to update their FMS position? Or can they do without these enroute updates?

TrainingWheels,
The way I understand it (disclaimer, I operate an aircraft with an FMS, however other FMS's could be different), is that the FMS updates its position mainly using the inbuilt GPS, and then uses VOR and DME in the event that the GPS stops working. However, there is also a way to tell the FMS which one you want it to update exclusively by (ie. if for some reason you want it to stop using the GPS, then just select VOR and DME).

I think I just confused myself writing that, so might be back to the book to update myself on exactly how it works, but that's basically the gist of it.

morno

Ok, thanks morno ... I remember reading about this for ATPL systems but that was years ago.

Hi, training wheels. This is an excerpt from a typical FMS setup for a modern airliner:
GPS is Primary if GPS is used as the primary source of navigation by the FMS. This happens on long oceanic flights where ground navaids are not available. If GPS is unavailable for whatever reason, the FMS will display a GPS downgrade message and you will have to rely on available navaid signals to quantify the position error of the FMS. In this case you should not rely on the FMS data for an approach and you would probably seek vectors and fly raw data based on ground navaids for greater navigation accuracy.

Thanks RF for the info .. it's a alot more sophisticated than than the UNS 1K FMS we use in our aircraft ..

They are not essential, but some of the are very very useful. Under the separation standards we use NDB's are more accurate than GPS under some circumstances. Also passing over a VOR/DME allows us the "reset" the nav tolerances of aircraft with IRS.

Wouldn't they have IRS? Admittedly that only covers en-route, but people flew non navaid routes long before GPS.

ReverseFlight thats interesting. The way I read that, GPS Primary averages three IRS and the GPS position and ignores navaids. Without GPS Primary, it averages three IRS positions and a radio fix, and adds GPS only if the GPS position agrees. The difference seems to be the trust in the GPS position. Is GPS Primary selected by the crew or the FMS?

Have ASA spoken to CASA about getting rid of VORs and NDBs?

To quote CAAP 179a

'4. If a TSO-C129 or C129a receiver is used at any time, or a C145a or C146 receiver is used during a period when FDE is not predicted to be available, an alternate visual approach or instrument approach based on NDB or VOR must be planned.'

Looks like the end of 129's for IFR use and very bad luck if you arrive with a 146 needing an approach when there is a RAiM outage.

There seems to be a lot more 146 fault detection outages than for 129's. Then a 146 becomes a 129 anyway.

Also,

'Automation Induced Complacency
The highly automated nature of navigational calculations using GNSS provides significant benefits including increased reliability, accuracy, proficiency and system monitoring ability. However, it can be difficult to stay alert and detect gross errors when monitoring automatic equipment. The operators’ continuing experience of highly accurate positioning information from GNSS can lead to the assumption of infallibility promoting a complacent attitude resulting in decreased crosschecking of the system.'

Well, that's alright now then... Let's just get rid of VORs and NDBs because we dont now need anything to crosscheck against anyway.... :ugh:

I refer you again to NPRM 1105AS, a CASA document.
This is the driver behind any decommissioning.

casa, icao and confusion with navigation
 

From the NPRM:

Civil Aviation Safety Authority - NPRM 1105AS


and:

and the big metal:

and:

How's that for creating more confusion between OZ and ICAO requirements - Bring on the next audit!!

Shutting down NDBs
 

On a related note, if NDBs were to be decommissioned, would GPS be allowed to be used in-lieu of NDBs?

I am in a situation where I am unable to do the SID out of YPJT due to not having an ADF, and have been told that GPS was in the pipeline to be approved in lieu of, then subsequently told that was not going to happen.

Given what I have heard/read, GPS is probably more accurate than NDB anyway?

I'd looked into getting an ADF a few years ago and was advised not to bother as NDBs were going the way of the dodo, that was back then...

Same with getting an HF - same mob suggested an installed satphone was the way of the future...

QFF, in short....no. GPS won't be allowed in lieu of NDB as a blanket change. The protection areas are too different. In order for that to happen the ndb procedure will have to be re assessed using GPS protection areas.

It's more than GPS being more accurate. It may be more accurate, but how do you know when you are getting that accuracy? It's for this reason the protection areas are a little larger than those for ndb.

Alpha

Check your RAIM prediction before flight. I suspect (only theorising here) that CASA is happy provided RAIM is predicted to be available. Perhaps, after that, if one sat then falls over, RAIM will still be available?

Because it's a TSOed system. Apart from the alternate requirement, the same GPS that could easily navigate QFF on the Mantl 1 would be used to take him to within 400ft of the ground, sight unseen, out in the boondocks (assuming it's a GPS NPA kit).

The system being TSO'd only means it will perform within certain accuracy limits as specified in the TSO. There is know way to know how the system is performing within those limits, like RNP can. So basic GPS protection areas have to cater for the worst performing TSO'd system.

A system being TSO'd has nothing to do with accuracy alone, more to do with accuracy vs performance

Yes I agree that QFF could navigate the Mantl 1 with the same perceived accuracy. And 90% of the time that might be the case. But protection areas are based on 3SD containment (99.7%) and on paper the figures reveal a wider protection area is required.

Admittedly, USA uses TERPS, not PANS-OPS, but they didn't seem to have a problem with GPS overlay approaches. GPS guidance was essentially used to track an NDB or VOR approach.

Different concept. I don't believe you can fly a GPS overlay approach without monitoring the navaid for the approach. Eg you can fly an ndb approach using GPS overlay, provided the navaid is tuned, identified and monitored for the approach. At least that's how I'm led to believe it is done. What QFF wants is to be able to fly the ndb procedure using only GPS in lieu of the ndb when the ndb gets switched off.

Without work done to re assess the approach, this won't happen.

Alphacentauri - thanks for your replies - that makes sense.

So I guess in the wider scheme of things, shutting down navaids would save money in the longer term but those savings might be diminished by having to have procedures re-surveyed/re-designed to different standards...

It may be cheaper to keep the damn things going...