RXP GTN RNAV Approaches

[Mad_X 12]

Hi there,

I recently changed my GTN system from the Flight1 product to the RXp offering because of the better performance and the newer features. 

However, I have one issue that I can fix: The plane does not recognize and follow the RNAV approaches. 

I select them them, press the approach button shortly before on the actual approach but the plane does not indicate any vertical guidiance or follow it with the AP. Wit the flight 1 it worked fine. Has anybody have a clue what might be wrong or what I am doing wrong?

 

 

[Gazzareth 808]

4 hours ago, Mad_X said:

Hi there,

I recently changed my GTN system from the Flight1 product to the RXp offering because of the better performance and the newer features. 

However, I have one issue that I can fix: The plane does not recognize and follow the RNAV approaches. 

I select them them, press the approach button shortly before on the actual approach but the plane does not indicate any vertical guidiance or follow it with the AP. Wit the flight 1 it worked fine. Has anybody have a clue what might be wrong or what I am doing wrong?

 

 

The Flight1 will show you the glide path when it shouldn't, with the RXP it only shows you it when it should. Flight 1 has the option to toggle this in the .ini with RXP it is apparently up to whoever has written the gauge code for the aircraft.

 

IRL unless you are running the full Garmin suite inc Autopilot you do not have Autopilot VNAV capability. Best workaround is to change the user fields to display TOD and VSR.

 

Came as a surprise to me initially as well!

 

G

[Mad_X 12]

So you cannot fly the VNAV portion of the approach with the RXP?I was under the impression is just fakes a GS to the FD which is then followed by the AP. 

 

[Gazzareth 808]

18 minutes ago, Mad_X said:

So you cannot fly the VNAV portion of the approach with the RXP?I was under the impression is just fakes a GS to the FD which is then followed by the AP. 

 

That was what I thought as well, but not according to Garmin. They have a video about it, which said to use TOD and VSR unless you have full Garmin systems on board. 

 

Was in exactly the same boat as you a month ago lol...

 

G

[Mad_X 12]

VSR you mean recommend VS right? 
so basically an LNAV only RNAV approach with higher minimums. Ok got it 😕. 

[Gazzareth 808]

6 minutes ago, Mad_X said:

VSR you mean recommend VS right? 
so basically an LNAV only RNAV approach with higher minimums. Ok got it 😕. 

VSR = Vertical Speed Required.

 

In the Falcon I tend to have it up all the time, in the Lear I would normally have that one showing GS until about 5 minutes before I plan on starting my descent...

 

G

[Mad_X 12]

So you use that during the approach too then. Interesting I only used it to plan my decent (mostly to the IAF). 

[ark 1,288]

5 hours ago, Mad_X said:

Has anybody have a clue what might be wrong or what I am doing wrong?

If an RNAV approach provides vertical guidance, then the RXP GTN should couple to the AP and fly the glidepath. If it is not, open the RXP settings window (by popping up the RXP into a 2D window and with the Shift key down, right click on the upper right edge of the RXP window) and check the settings. It should look something like the below. Note although some settings are locked and therefore dim even when on, of the first 7 settings only Connect GPS to VOR should be off (very dark square).

Al

 

 

Edited February 9, 2020 by ark

[Gazzareth 808]

1 hour ago, Mad_X said:

So you use that during the approach too then. Interesting I only used it to plan my decent (mostly to the IAF). 

No, only through the STAR &/or transition once you hit the actual approach then if it has vertical guidance you should then get the actual glidepath indicator as Al said above. I think at that point VSR blanks out anyway, either way I don't look at it from then .. .. if you're coming from the F1 GTN then you can actually have a glidepath indicator from as soon as you choose an approach or enter an altitude restriction - I was assuming that's what you had before?

 

G

[Mad_X 12]

Correct. I will make a few test 🙂

[ark 1,288]

Just to clarify, VSR information is only advisory even if the GTN is flying the lateral course (SID, Star, Enroute) coupled to the AP. You have to make the advisory VSR happen manually. It is only during an approach with vertical guidance that the GTN750/650 will fly the GP automatically when coupled to the AP.

Al

[Mad_X 12]

That is clear, but nor working with the RXP. It does with the Flight1. However, it seems that Gazzareth has a point here.

[ark 1,288]

36 minutes ago, Mad_X said:

That is clear, but nor working with the RXP. It does with the Flight1. However, it seems that Gazzareth has a point here.

I'm not sure what you are referring to when you say 'it' is not working for the RXP. The RXP will certainly capture an RNAV approach glide path and follow it when coupled to the autopilot. If that is what is not working for you, we need to figure out why. What exactly are you seeing, or not seeing?

Do you have the latest versions of the RXP, the Garmin Trainer, and the Falcon50? And what sim are you using?

Thx,

Al

Edited February 9, 2020 by ark

[Nickbe 401]

I can confirm that the autopilot on the Falcon50 makes an automatic approach RNAV (LPV) with the RXP GTN750. But I checked it on the 1.8C version of Falcon50 .

[Mad_X 12]

On 2/10/2020 at 7:18 AM, Nickbe said:

I can confirm that the autopilot on the Falcon50 makes an automatic approach RNAV (LPV) with the RXP GTN750. But I checked it on the 1.8C version of Falcon50

So, how to get it to do that again? Dod work on the Flight1.😕