Removal of DGA approaches
 

I'll admit I was a bit shocked when I got the May amendment to DAPS to see the removal of several DGA approaches, in conjunction with the decommissioning of NAVAIDS.

I understand a DGA requires a NAVAID as a reference point, however I'd assumed an alternative, even the aerodrome itself as a GPS waypoint would suffice (I understand navaids can be offset by some distance but in the majority of instances, they aren't and could be resurveyed)

Did I miss something in the briefs from Airservices that these approaches would be removed in addition to the actual approaches associated directly with the Navaid?

Shannon

Didn't know they were supposed to go, but a good idea still! Creating DGA approaches without a ground based aid would be an anachronism.

Why would that be anachronistic. I actually think it would be forward thinking and flexible. DGAs are often a great help in IMC. Getting onto the 25 approaches in Albury is a real pain if just using LSALTs or MSAs. You either need to hold to get down or get high RODs. The DGA provides the flex to get down.


GPS can be used for stand alone approaches = why not for GPS arrivals?

The concept of DGA where you have a you beaut GPS accurate to 0.3 nm for your distance and then rely on a wandering ADF needle pointing to a station that may not be within the confines of the airport boundary always had me wondering "why?".
Wouldn't it be possible to create an "approach" that would take you to a cloudbreak altitude ..below the 10 mile MSA and close to the circling minima ...based on a GPS track. Sectorised DGA's were ok with an NDB ...what's so bad about the lateral tracking of a GPS?
I know circling approaches are fast becoming persona non grata amongst the heavy metal but a circuit sometimes can be the most efficient way to effect a landing

They already are, they may have made sense when CSIRO invented the Australian DME, and maybe made some sense until appropriate RNAV approaches could be developed, and the technology matured.

In the case of albury they clearly need some more RNAV approaches.

Time to keep up with the times.

An RNAV approach is cheaper and more accurate, lining you up on finals at a lower minima. Surely this is more desirable than breaking visual in the 'vicinity' of the airport and visually manoeuvring to get on finals.

Cheaper??? Cheaper for who?

Flying into devonport from Hobart for example, with a east / west runway and inbound from the south - is going to add a lot of unnecessary track miles by doing a RNAV approach if it's say BKN at 2400'.

I have no issue in breaking visual in the vacinity of an Aerodrome and conducting a visual approach, a visual approach is cheaper to fly than a procedural approach

In a C172 it may add an extra 2.5 mins in your example, approaching from the east or west and landing the opposite direction is more of an issue. That would add in the order of 30 + track miles.

Many of the AUS RNP procedures used navaids as waypoints. Doesnt matter if it is operational or not, it is a waypoint defined with GPS coordinates.

https://www.airservicesaustralia.com...MLGN04-140.pdf
https://www.airservicesaustralia.com...SYGN05-142.pdf
https://www.airservicesaustralia.com...SYGL01-142.pdf

That just depends on the constraints placed on the design. Due to environmental issues (ie, the screaming public) many are forced to be overlays, not allowing for short finals.

RENURPP,

Couldn't you just do the RNAV for the opposite runway and then circle off the bottom as you would for a DGA?

http://www.airservicesaustralia.com/...LIGN01-146.pdf

flying a cat c aircraft now has a minima of 1370 if you're going to land on the longest runway, with a requirement to stay to the west of the aerodrome ... that's going to be fun today with the wind :mad:

SPECI YFLI 120030Z AUTO 26033G44KT 9999 // SCT023 BKN030 OVC036 16/12 Q1003

Dont let the truth get in the way of a good story.

The current DGA's at YFLI all come in from westerly directions. With todays weather most available options are not that good. Removal of the DGA's does make this situation worse.

I fail to see the point you are making..

Don't you guys have Distance Steps your airways?

If I understand the DGA it's really just a step down procedure based on a track MSA. Distance steps on an airway achieve the same thing.

There's also TAA's which can be used in a similar fashion.

yeah Apart from the 14 mile descent to 2100 feet allowed on the dga on the LT-FLI approach, meaning you'd be breaking visual, with less of a tailwind and less tracking than doing a RNAV

Likewise the 1400 descent at 20 miles on the DPO track

Just like to point out that they are not the same thing. Jets will always be doing visual circuits because as you point out they are the most efficient way of arriving and usually via the DME arrival.

'Circling approaches' are a whole different matter entirely.

Yes, assuming there is no conflicting traffic and then only to circuit altitude in VMC. As discussed above we are not permitted to fly a circling approach.

What is the technical difference between the two?

ie what is stopping someone from conducting the RNAV approach down to the Straight in MDA and then conducting a "visual circuit".

Seems to be a bit of a grey area where you can call anything a "visual circuit" to circumvent the no circling area and circling approach MDA.

Or am I missing something?

straight in mda is typically a lot lower than you'd comfortably circle at for a start.

Clearly you'd climb if required to an altitude at which you are comfortable to fly a standard visual circuit.

mike, whats your ifr background so that others may be able to help you with your understanding?

Yes

AIP ENR 1.5 0-3

1.7.2 Restrictions on Visual Circling

Should help you find it

The difference.
A Circling Approach is an instrument approach to the circling minima followed by a visual circuit (provided all the parameters are met), to land on the OPPOSITE runway. Airports may have restrictions on this due to terrain, built up areas etc. So Mikewil, your RNAV to the minima then a 'visual' circuit is essentially a circling approach, however these are Non Grata as stated.
If you were to land on the opposite runway and there was an RNAV approach provided, surely this would be your best option in the first place.
A visual approach is an approach with no Nav aid reference.
As far as my cheaper remark is concerned, I have to admit it is cheaper for the provider rather than the user.

Big difference between a visual circuit and a circling approach is that the circuit is flown in VMC while the circling is not VMC, i.e., it is IMC but with the required minimum visibility.

Not always as clear cut as that though.

For example, If we have 10km visibility below a cloud base of 1000 and the only way to get down below that base is an RNAV to straight in minima, would you be breaking any rules by 'circling' to land on the reciprocal runway?

Clearly this is a breach of the regulations, but one could argue that you are now in VMC and can conduct a visual circuit to the reciprocal runway. Despite having descended way below the circling minima to break clear of cloud.

I would say the intent of the AIP is clear, though I would agree it's not exhaustive and I note it doesn't say 'don't crash' either. Ironically that part of the AIP has been amended at least once because of a hole in the ground.

In your example if you are in VMC and allowed AND ABLE to operate under VFR, switch to VFR, same as any stage of flight, otherwise I would suggest you must immediately initiate a missed approach.

In the USA, the rules are very clear, but in many cases you would be much closer to the ground at the circling MDA. (they use a different criteria than Australia). I note that NZ has adopted the FAA wording.

It's certainly clear to me what is required. Perhaps if they spent all that money on those farcical new regulations on well designed and modern approaches your question would not arise, which brings us back somewhat to the original topic...

This is the logical way of putting it I was trying to get at.

Would that argument hold water if you had to justify your actions to the regulator?

"I conducted a full instrument approach to straight in minima then changed to VFR for the remaining 2 minutes of the flight to circumvent IFR circling requirements".

From a practical point of view I don't see much of a problem with it but somehow I don't think CASA would like it too much.

Why not put in a "cloudbreak" RNAV-Z down to the circling MDA only for places where the runway-aligned RNAV-Z takes you well out of the way and wastes a lot of fuel/time?

'From a practical point of view', flying a missed approach means climbing and tracking as per the missed approach, and continued VFR flight DOES NOT include a missed approach...

Perhaps your example refers to flinders island mentioned.

http://www.airservicesaustralia.com/...LIDG01-146.pdf
http://www.airservicesaustralia.com/...LIGN01-146.pdf

In an attempt to return again to the original topic, you have effectively lost 2 instrument approaches. My original point is it would be better to have them redrawn as RNAV approaches. I can't imagine its a big job if they just had a circling MDA, as that is essentially what you have now... (or a few more days). I would suggest there is also the opportunity to offer two additional RWY approaches.

The Sector B at Flinders I is about as good example as any, as to why these DGA approaches are not the way forward... However the way forward should not be a step backward which seems to have occurred at Flinders Is...

By way of example here is a similarly constrained airport in the USA... (In class E ;))

Charts at bottom of the page:
https://www.airnav.com/airport/KHAF

If you are claiming it is now VFR and you are flying a visual circuit how are you going to join the pattern? If you are VFR you are supposed to join crosswind or down wind at circuit altitude not 450' AGL. If it was quiet it would be doable, if it was a busy airport I think you would have difficultly actually complying with the traffic pattern. The other issue is that if you are now playing VFR in marginal conditions how do you deal with the MAP, especially if you are out of the circling area.

Or why not a GPS Arrival with the Aerodrome reference point as the waypoint?

In reality the government should really be making RNAV approaches at every airport and getting RNP approaches made for where RPT jets fly.

Neville,

the last time I had a look most of the rpt jet operations had some sort of GPS approach. There are now at least two companies other than no services that will design for a cost. Places like mines have been paying for them for some time as a risk mitigation for fly in fly out. :cool:

Correct me if I am wrong, but i cant think of a single registered aerodrome that doesn't have at least one gnss approach. Most will have 2 by the end of this month.

There are now at least 5 other organisations certified to provide instrument approaches in Aus.

Yes it would be possible to develop a criteria for gnss guidance arrivals in Australia, criteria only currently exists for conventional azimuth guidance. Note these are not icao procedures. The new critetia would require extensive safety work and testing, again not impossible. The roadblock is casa's insistence that we only design approaches to icao rules. They are not interested in developing any new Australian rules

Lightning Ridge off the top of my head.

Fellas that's my point why are we paying for it?
Anyone who operates an aircraft in Australia is getting raped. Paying more and more everwhere for less and less. Everyone has their hand in your pocket for no outcome. We are about to lose a whole heap of navaids and what do we get in replacement?

As I said it should be an RNAV approach at every airport and RNP for jet operations plus a few more ILS's.

The powers at be would probably want every single operator to have to their own individual GPS approach that they then have to individually approve for every airport ensuring ongoing fees perpetually for all those involved.

West Angelas is another.

As for getting visual below the circling MDA, but before the straight in min, and circling, :=

West Angelas should have approaches within the next 2 months.

As for navaid decommissioning, every location that supported a ground based approach was replaced with an rnav approach. This was some 60 locations across the country, all effective by the end of this month (check sups).

Except they have not replaced the DGA approaches in any meaningful sense... Flinder Is is an excellent example. [Edit ] Perhaps that's an isolated example.

Its not rocket science to come up with some reasonable criteria to translate and redraw them, each quadrant would be good starting point...

A bit sad really, I would be annoyed if I was involved in an operation effected by this.

From somewhere in the back of my head there was an intent to remove ( stated or not ) circling approaches in favour of runway aligned. Usually the minima is a lot lower than for a circling approach. As for track miles trade off tracking direct to the initial point for the approach from a reasonable distance out. this was also done to provide forced separation and not have everyone tracking over the same point in space at the ARP or NDB.

The initial choice of runway direction was also supposed to address the worst wx situation if air no services could only do an approach for one end.


as for descending on a gps approach to MDA then circling to the other end of the runway may require experience in very low level circuits and not very healthy. :ugh:

That depends on how far they go with the rationalisation. I can think of at least 5 airports off the top of my head around Australia that if your only option was to fly runway aligned approach from 10 NM it will add significant track miles (ie 30NM) to the majority of arrivals. According to the AIP SUP though they don't plan to close any more additional aids in the near future.

I would assume CASA are hoping that the airlines pony up for RNP approaches (which has already happened) and everybody else will just have to pay for the additional fuel burn.

Talking of YFLI looking at the Jepp amendment package, ERC 7/8 shows NUNPA as the reference point for all tracks. One would have assumed that the name Flinders Island would have been retained, to help with VFR and IFR traffic separation?

Do not recall anyone mentioning the DGA/GNSS arrivals being removed during any of sessions on navaid rationalisation information sessions?

What about RAPAC, or that just for the VFR weekend warrior brigade?