RNP APPROACHES

[jialarcon]

Hi, can you fly RNP approaches with this product ?

Regards

José

[Bourrinopathe]

This looks quite complicated (and interesting) as the RNP (Required Navigation Performance) approaches seem supported by the GTNs, but also seem very similar to the RNAV (GPS) approaches with LNAV/VNAV.

(I've added a Wikipedia link for those who (like me) didn't know what a RNP is)

Based on a note from the Garmin supplement to the Airplane Flight Manual:

Quote

The Garmin GNSS navigation system complies with the equipment requirements of AC 90-105 and meets the equipment performance and functional requirements to conduct RNP terminal departure and arrival procedures and RNP approach procedures including procedures with RF legs subject to the limitations herein. Part 91 subpart K, 121, 125, 129, and 135 operators require operational approval from the FAA.

For reference, here's the FAA Approval Guidance document for RNP approaches.

Another interesting read about the RNP approaches.

Based on these references, it looks like it's possible to use the GTNs for some RNP approaches.

Quote

[…] it’s important to understand that if your airplane is equipped with, say, a GNS530W or one of the new GTN boxes (with an appropriate AFM supplement), you can fly RNAV SIDs and STARs based on RNP-1 criteria. And you can, of course, fly en route segments that require RNP-2 accuracy.

May I ask what aircraft you intent to fly with the GTNs and why the RNP approaches are important? (I'm not a pilot, so I'd like to learn more if possible)

[MartinRex007]

Mc Clellan-Palomar Airport KCRQ in San Diego Calif has a listed RNP approach if you want to practice flying it, haven't flown it yet so not sure if my F1 GTN 750 is up for the job, I'll try it tomorrow.

Cheers

Martin

[signmanbob]

Interesting. It basically looks like just an RNAV approach with a standard 3-degree constant descent.  It is listed as RNAV (RNP) approach.

I don't guess that there would be any special setting for doing RNP. That seems to be more of an accuracy standard for the box.

[RXP]

11 hours ago, MartinRex007 said:

aven't flown it yet so not sure if my F1 GTN 750 is up for the job

Let's hope your Reality XP GTN 750 Touch is up for the job instead in this forum!

[scottb613]

Hi Folks,

I believe what makes RNP's unique - is flying a curved radius to a fix... I believe they are used where adequate terrain clearance can't be maintained for a more traditional approach...

The F1 GTN wasn't capable of flying them - the approaches weren't contained in the database - I haven't looked at these in the RXP version... I used KPSP for my testing... It was a feature added a couple years ago during the GTN's life cycle... Your aircraft also needs specific FAA certification to be cleared for them - even if your GTN is capable...

Regards,
Scott

[RXP]

3 minutes ago, scottb613 said:

I haven't looked at these in the RXP version... I used KPSP for my testing...

Hi Scott, it is way above my piloting skills, but I'm wondering about your findings once you get a chance to test it!

[scottb613]

Hi Jean-Luc,

Sure - my pleasure - I only get home on the weekends though - will do it then and post here when I do...

Regards,
Scott

[RXP]

@scottb613

[MartinRex007]

1 hour ago, RXP said:

Let's hope your Reality XP GTN 750 Touch is up for the job instead in this forum!

My bad, sorry

[Bourrinopathe]

I just checked the GTN North America database at KPSP.
Both RNP charts are available but you can only load and activate the "VOR or GPS-B" approach.
The other options are the visual approaches on RWY 13 and 31 (R/L).
Juneau (PAJN) also doesn't have any RNP approach available but afaik they're specific to Alaska Airlines.

[RXP]

Please note there are sometimes exclusions with certain DB cycles. I can't tell you exactly which they are for the GTN DB you are using, but the latest info is here:

https://avdb.garmin.com/docs/garmin_data_exclusions.html