Help! Garmin .gfp file spec for RNAV (GPS) Y and Z approach types

[fppilot 4,360]

I have gone through the Garmin Guideline for GTN Flight Plan and User Waypoint Files to better understand the nuances of including Departures, Arrivals, and Approaches in Garmin GTN spec .gfp files, which can be imported into the RXP GTN series gauges.  I have built a spreadsheet that helps create .gfp files.  I have had great success so far with understanding how to construct .gfp files with departures, arrivals, and ILS approaches.  Where I am stuck is trying to include RNAV (GPS) Y approaches.  Wondering if anyone here can help,

The Garmin "GTN Flight Plan and User Waypoint" pdf shows codes for use in gfp files and examples of the codes in use, using approach types (as coded by the FAA, reference ARINC 424) .  I listed those below,  

Here is an example of how to include the approach to KIND's ILS 30L

FPN/RI:F:KMKC:F:SAAGS.J80.VHP:AA:KIND:AP:I30L

The :AA: calls the airport KIND, and the :AP: calls the approach,  I30L.   The  letter I calls an ILS approach  and the 30L calls the chosen approach.  Works great for ILS approaches.

Where I am hitting a dead end is in figuring out how to do the same for say RNAV (GPS) Y RWY 14.  

As you may see in the table below, there are several letters that may apply.  K, P, R, and elsewhere I found references to additional letters of W (for WAAS) and E (another for GPS).  The GTN is rejecting all attempts as it cannot find the procedure.  I have also tried Y and Z, and have used Y in combination with each letter, trying those on each side of the runway number.  My examples are for the letter R, I tried these with the other letters as well and also used the IAF intersection as a suffix following a "."  Suffixes can be used but are not required for ILS approaches.

Anyone know the answer to this?

AA:KIND:AP:R14
AA:KIND:AP:R14Y
AA:KIND:AP:RY14
AA:KIND:AP:R14-Y
AA:KIND:AP:R141
AA:KIND:AP:R142
AA:KIND:AP:R14-1
AA:KIND:AP:R14-2

=========================================
Guideline for GTN Flight Plan and User Waypoint Files

• B-Localizer/Backcourse approach
• D-VOR/DME approach
• I-ILS approach
• K-WAAS/GPS Approach
• L-Localizer only approach
• N-NDB approach
• P-GPS approach
• Q-NDB/DME approach
• R-RNAV approach
• S-VOR approach using VORDME/VORTAC
• T-TACAN approach
• V-VOR approach
• CNDB-NDB circle-to-land
• GPSC-GPS circle-to-land
• CVDM-VOR/DME circle-to-land

[RXP 2,338]

Hi, I've not tried it out, but looking at the reason for the extra 'Y' or 'Z' letter here:
http://ww1.jeppesen.com/download/aopa/jan01aopa2.pdf

I'd suspect you might need to prepend the name with the letter.

It might use 'P' as GPS ?
https://flightaware.com/resources/airport/KIND/IAP/RNAV+(GPS)+Y+RWY+14

AA:KIND:AP:PY14

it might use 'R' as 'RNAV'/'RNP'?
http://155.178.201.160/d-tpp/1802/00203RRZ14.PDF

AA:KIND:AP:RZ14

?

[fppilot 4,360]

Thanks Jean-Luc, 
Found all of those plus others today but no cigar.  This became one of those "just spent 30 minutes, but I know I can solve this", to "now it's been three hours and I am p'd cause I know it's something small I am missing. Then it became 6 hours of research and trial and error, and then 8 hours!  Why is it always the drive to overcome a challenge that overcomes us!

Not done with this. But done with it for today....  Because it's already "tonight"! LOL!

[RXP 2,338]

10 hours ago, fppilot said:

Why is it always the drive to overcome a challenge that overcomes us!

This is so true, but in the end, this brings products like the GNS V2 and the GTN to fruition!

It might also be a case where the gfp loader code is not capable of parsing these, or it just the forest masking the tree. I can't look at this specifically right now, but I'll try to remember checking this in the future.

[Indy511 686]

19 hours ago, fppilot said:

Why is it always the drive to overcome a challenge that overcomes us!

Flight Simmers motto.

[fppilot 4,360]

8 hours ago, RXP said:

It might also be a case where the gfp loader code is not capable of parsing these

Got in contact with Garmin Aviation division today and unfortunately sent them scrambling. Simple question, referenced their publication by publication number and then page number and they could find no one present that could address the question.  They got totally confused about the difference between a FPL (or now FPLN) "folder" and a ".gfp" file.  Kept responding that the GTN would only  accept import of an FPL file even when reading me the publication's sentence that described both, one as a folder and the other as a file type.  They did contact the team responsible for the publication and then got back to me later by email.  

The GTN can load RNAV (GPS) approaches if only one exists for a given runway.  Reference for instance KBMG, Bloomington, Indiana, with single RNAV (GPS) approaches for 17 and for 35.  Or KOJC, Johnson County Executive, Olathe, Kansas, which has single RNAV (GPS) approaches for 18 and for 36. 

When an airport, on the other hand, has multiple RNAV (GPS) approaches for a given runway, such as at KIND, Indianapolis, Indiana, where Runway 14 has both a RNAV (RNP) Z 14 approach and a separate RNAV (GPS) Y 14 approach, the GTN import feature lacks the capability to distinguish between them and returns an error. 

This is a .gfp import issue and does not at all affect the GTN's capability to add any of the published approaches to a flight plan already stored in the unit.  

At KOJC and KBMG I confirmed that the appropriate Code letter within the .gfp file spec for RNAV (GPS) approaches is "R" (see chart in original post above).  The two that reference GPS, Code K and P, do not work.  Separately, the Code of "I" for ILS, and "L"  for LOC approaches do work for me, but are likely limited in the same ways when multiple approaches of the type to a single runway exist.

Here is how the .gfp file for a flight from KSUS to KBMG looks when spec's for RNAV (GPS) 35 with the BEHWY transition.
FPN/RI:F:KSUS:F:SNYDR.V12.BIB.V221.RACYR:AA:KBMG:AP:R35.BEHWY

I can plan my flights at Fltplan.com, quickly enter the fixes and or airways into cells in my spreadsheet, use concatenate formula to create the line, with required punctuation.  I then copy/paste into notepad, save from there as .gfp. Then it is ready for import in the .gtn.  Sounds like a lot to do, but once familiar with it the process is very quick and provides a great archive for flight plans for often used routes,

Edited March 1, 2018 by fppilot