NAV/GPSRNAV VS PBN/RNP2 and you
 

Until July 13th, GPSRNAV is seen as equivalent to RNP2 as a navigational tolerance ATC can use for separation. Come July 14th, GPSRNAV is consigned to history - it is an extolerance, shuffled off this mortal plane, fallen off the navigational perch.

ATC use a screen based presentation of the separation tolerance we can apply between aircraft which is dependant on how the flight plan is filled out. At the moment when pilots flight plan GPSRNAV we get an indication that no GNSS gear is carried. When we open up our electronic copy of the flight plan and see GPSRNAV we know what separation standard we can apply and adjust your flight plan to get the right screen indication (GPSRNAV=RNP2)

Come July14, GPSRNAV ceases to exist and I'm betting the rule will be ATC can't make the substitution.

Upshot is to get your flight planning in order before July 14 (there is an AIP SUP) otherwise ATC will be forever asking "are you RNP2?" or using 30nm cross track as opposed to 7nm which won't help you or me...

Interesting there 'fso' as I always thought that GNNSRNAV or GPSRNAV was a bloody mouthful & could be seen as slightly confusing seeing as there are RNP's. How do you guys go when the 2nm drops to 1 nm during the intermediate phase for Eg then to 0.3 for final? I guess by then it's the fore & aft separation that's important.
RNP2 I note on a Flt Pln (the portion that ATC have as their record) is a stand alone statement & not included in the body of the other RNP lateral allowances, maybe that was deliberately done for such as what your saying is about to happen shortly.
I better go have another read since I gunna be 'simmed' 2moro night:{

H43/14 if anyone wants to gloss over it.


Wmk2

Thank you fso28 for the “heads up”! Thank you Wally for saving me the search!
I read the AIC again & checked Jeppesen – Air Traffic Control – AU-607 4.3.
I accept the thrust of what fso28 says and as para 4.3.2a allows a choice. It is probably wise to insert the second CHOICE in field 18 of the flight plan form “NAV/RNP2 GPSR-NAV” [according to JEPP.] to satisfy ATC’s screen presentation.
The AIC suggests “NAV/RNP2” is sufficient. Which is it?
As well, Jepp, para. 4.3.2 has part a and b. The way I have interpreted it is to insert for (a) AND (b). Perhaps in light of the AIC, it is meant to be (a) OR (b).
Any thoughts appreciated.

I rang briefing office this afternoon before filing today, NAV/RNP2 is sufficient.

If you notify RNP2 as your standard you are signifying you are purely an enroute user. If you are doing an RNAV appch, then you will be notifying RNP APCH (S1 or S2 w/baro aiding). The GNSS doesn't drop to the 0.3nm RAIM limit unless an RNAV approach is activated.

Even if you are in Terminal mode, you would expect that ATC are aware of your departure and destination. If your RAIM limit is exceeded, you just notify as per AIP ENR 1.1 Section 21.3 and a different based separation standard (ie. non GNSS) will be applied.:ok:

Maybe the Ranga could confirm?

I am aware of that tnxs 'MIHC' thought that it was basic info hence I didn't mention the activation of App phase in the body of my text.



Wmk2

Is this RNP2 for terminal or en-route?

Sorry, Wal. Not insinuating you don't know your stuff. Just general info.

Can I expand a bit on why correct flight planning will be so important post July 14 for ATC?
Even after we moved into TAAATS, if I had to use navigational tolerances for separation I'd use a chinagraph pencil, plastic spanners for NDB or VOR and a scale ruler, then draw it all up on an overhead map to give me my separation points.
TAAATS now has software which let's me do that electronically and puts all the info I need on the screen through selecting the appropriate nav tolerances from a drop down menu. Press "enter" and shazaam, a diagram on the screen tells me everything I need to separate.
Correct flight planning is the key to making all this pizazz work.
I'm an enroute controller, things are pretty straight up for me. If you've got RNP2 in your flight plan all will be well for you and me. If you've got GPSRNAV post July 14, expect questions!!!
Do I still use chinagraph pencils, spanners and rulers? Yes, sometimes it's the only way to get the best solution - but not often!

fso28

I read the AIPSUP, if I file RNP2 it indicates to you that I am an enroute user only...probably good for you. But the AIP SUP indicates that if I want to show I am RNP APCH capable then I have to file PBN/S1 or S/2.....if you see S1 or S2 do you know that I meet the RNP2 criteria?

Or am I missing something and do I have to file NAV/RNP2 and PBN/S1 at the same time?

To add to the confusion...only 6 weeks ago I sat in a room full of industry representatives including CASA, AOPA, AsA, REX, Qlink, Virgin and nobody had the same opinion on what needs to go on a flight plan.

Alpha

That's ok 'MIHC' I probably don't know my stuff as you say:{:ok:

Tnxs again 'fso', good to see you guys helping us drivers out a little, remember though we drivers don't do the 'fright' planing so I best check our fright plans more carefully am surprised there's more than just basic VFR stuff added:-):-)


Wmk2

Airbus A320/330/340 only mentions RNP 4 and RNP 10 for en-route. Does this mean there must be a special upgrade required for Aussie airspace (???) or am I missing something? All these aircraft are certified (ours anyway) for RNP 1 (terminal) and RNP-APCH (approach). How did CASA come up with this Nav Spec?

Read the post by MIHC directly above your post! You could also read the AIP SUPP...

Probably from ICAO.

430W
 

So for my bugsmasher flying IFR with Garmin 430W I file:

-G
-R
-Z

And in field 18:
NAV/RNP2 PBN/S2 PBN/O2

about to submit - lets see what happens

You will be correct & subject to the minimum nav tolerances ensuring better separaration standard outcomes :ok:

I'm not the Ranga, but the non-surveillance separation standards available to ATC currently do not accommodate anything under 7NM CEP (= RNP2 for ATC). The non-surveillance Towers cannot practically use this standard either as they do not have the same tool that the Centre has for computing lateral separation on the fly.

There is one exception and that is where the aircraft is on final for an RNP approach (read old RNAV GNSS approach), when the final approach course can be considered equivalent to a LOC for separation purposes.

Incidentally, terrestrial navaids (even NDBs) can usually provide better separation solutions in terminal areas than RNAV standards.

Finally, plan NAV/RNP2 and whatever else you're qualified and equipped for! :ok:

I'm pretty sure the 430W has baro aiding, if installed IAW AC21-36(1), and not baro vnav which would mean PBN/S1 and not PBN/S2 would be correct. Happy to be corrected. FAA AC90-100 is fairly self explanatory though.

https://www.faa.gov/about/office_org...compliance.xls