Difference between RNAV and RNAV-Z approaches

[Juliet_Lima]

This is my first ever post on pprune, so please be gentle.

Can anyone tell me what the difference is between an RNAV and RNAV-Z approach in Australia please?

About 10 to 20% of the RNAV approaches in the DAPs are listed as RNAV approaches and the other 80% are RNAV-Z approaches.

I've spent hours googling this and cannot find an answer. There are lots of sites that talk about the difference between RNAV-Z and RNAV-Y, but none that compare RNAV vs RNAV-Y. There are RNAV-Y approaches listed for Norfolk Island, but none on the mainland.

Happy New Year

Juilet Lima

[AerocatS2A]

What is supposed to be the difference between a Z and Y approach?

I had thought it was simply to differentiate between multiple approaches to the same runway, (this is what Jepps says it is for), but that doesn't explain why Norfolk Island has an RNAV-Y and no RNAV-Z and it doesn't explain why some places have an RNAV-Z when there is only one approach per runway. From a flying point of view there is no difference between an RNAV (GNSS) approach and an RNAV-Z (GNSS) approach.

[Jabawocky]

And for something different check Thangool, it now has an RNAV-E

[training wheels]

It's where they get the DME from I believe. For example, ILS-Z RWY 16 at Melbourne use IMS as the DME source.

http://www.airservicesaustralia.com/aip/current/dap/MMLII03-140.pdf

But ILS-Y RWY 16 at Melbourne uses the ML DME.

http://www.airservicesaustralia.com/aip/current/dap/MMLII01-140.pdf

[AerocatS2A]

That's for an ILS, RNAV approaches don't have a DME as part of the approach.

[training wheels]

Ah yes .. I should have read the question more thoroughly :ouch:

[alphacentauri]

Juliet_lima, there is absolutely no difference between an RNAV-Z and an RNAV approach.

The suffix are used to differentiate between 2 approaches of the same type on to the same runway. For example at Gold Coast on RWY 14 we now have RNAV-Z/X/Y and M/P...The procedure coding of the approach name is RNV in all cases hence the suffix requirement

About 5 years ago the decision was made by the powers that be that we would future proof all of our RNAV approaches with the suffix Z. This has recently been found to be necessary and premature, so they are being taken out.

AerocatS2A - Norfolk Island has X/Y not sure why they never went for Z. Not sure of any rule that says you have to start with -Z

As to the -E suffix. There are some approaches across the country that do not meet the PANS-OPS or MOS 173 criteria for straight-in approach minima. This does not mean we can't publish an approach, we just can't publish a runway specific straight in minima. Where the minima is restricted to circling we use the suffix A/B/C....for NDB/VOR approaches, and we use the suffix N/S/E/W for RNAV approaches (this gives some situational awareness to pilots as to what direction the approach is from)

Hope this answers your question

Alpha

[Jabawocky]

Awesome answer AC :ok:

Pity that was not more "common knowledge" but now it might be a bit more so! :D

[slackie]

Auckland also has RNAV X/Y/Z approaches to both 23L and 05R, although the X approaches caught the attention of some greenie NIBYs and have had a wee hiatis for a year or so... but (in true Arnie tradition) they'll be back!