What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

GTN650xi issue

H

Hangar 1271

Well Known Member
I have been having a problem getting my GTN650xi to automatically switch from GPS to ILS on an ILS approach. A GPS approach works fine. I'm also using a Dynon Skyview D1000T and the Dynon AP but I have been hand flying these practice flights. I finally determined it is likely that I am activating the approach outside of the defined area in which the GTN will make the switch automatically. I usually, for practice flights, load the approach on the ground at the airport I will take off and return to (same airport). I noticed yesterday that the load option was grayed out and only load and activate was available regardless of approach type. I reasoned it was because I was at the airport and it figured if I'm this close I must mean to activate it. So, today I didn't load the approach on the ground and flew out well past the IAP. When I went to load the approach the load option was still grayed out and only load and activate was available. I retried to load again less than 15 nm and on the localizer extended path from the FAF but no improvement. I've read the manuals several times, searched VAF, searched Garmin's support site (useless as usual) and can't find an answer. I looked for a phone number to call Garmin but that seems to be well hidden.

Any suggestion? The problem is probably user error. It usually is but it is still an issue for me.
 
Hangar 1271 said:
I have been having a problem getting my GTN650xi to automatically switch from GPS to ILS on an ILS approach. A GPS approach works fine. I'm also using a Dynon Skyview D1000T and the Dynon AP but I have been hand flying these practice flights. I finally determined it is likely that I am activating the approach outside of the defined area in which the GTN will make the switch automatically. I usually, for practice flights, load the approach on the ground at the airport I will take off and return to (same airport). I noticed yesterday that the load option was grayed out and only load and activate was available regardless of approach type. I reasoned it was because I was at the airport and it figured if I'm this close I must mean to activate it. So, today I didn't load the approach on the ground and flew out well past the IAP. When I went to load the approach the load option was still grayed out and only load and activate was available. I retried to load again less than 15 nm and on the localizer extended path from the FAF but no improvement. I've read the manuals several times, searched VAF, searched Garmin's support site (useless as usual) and can't find an answer. I looked for a phone number to call Garmin but that seems to be well hidden.

Any suggestion? The problem is probably user error. It usually is but it is still an issue for me.
Click to expand...
Just an idea if this persists.
Get a simple camera phone holder with PFD/AP/GPS in focus for a flight. Then you and the audience can help if it is a buttonology issue.
Also, consider writing out each step you do while in the air. Then share that.
How is ILS radio tuned?
What airport?
Are you confirming in the flight plan that this is loaded?
Is your NAV source set to the 650?
 
Last edited:
Make sure your Auto Switch features are properly configured on EFIS as well as GTN Xi

For All Garmin products installed into Experimental aircraft:
Justin is a great source of info:
Garmin G3X Support
[email protected]
1-866-854-8433 - 7 to 7 Central Time M to F
 

There are two scenarios when performing an approach. Vectors to final and a full approach. I assume you are having issues with the VTF scenario. When performing a Vectors to final approach, you should load and activate the approach as soon as ATC begins vectoring you to final. You can verify this is active by the magenta extended center-line of the runway. The autopilot should be manually switched to the heading mode from the NAV mode. When you are cleared for the approach, you then activate the Autopilot approach mode, which activates vertical guidance. The GS or GP will only be intercepted if you are below the glide path. At this point, you have received your last ATC vector, and when your are within 1.2 NM of the final approach course, the GPS will auto switch the CDI from Heading mode to LOC. When you hand fly the approach it is essentially the same procedure, but ignoring the A/P activation.​

BTW, when you load an ILS/LOC approach, the GTN loads the LOC frequency in the standby window. You have to manually move the freq. to active.

Hope this helps!

​

From Garmin:​

When does the GTN (Xi) switch the external CDI output from GPS to VLOC ?​

The GTN automatically switches the external CDI output from GPS to VLOC as you intercept the final approach course. When the ILS approach activates and the correct ILS frequency activates in the VLOC window, the GTN automatically switches to VLOC within 1.2 nm left or right of the final approach course. This switch can take place anywhere from 2.0 to 15.0 nm from the FAF.

This illustration shows multiple locations along the approach path and the CDI selection that you can expect: GPS or VLOC. The shaded area depicts where the automatic switch from GPS to VLOC should occur.



GPS to VLOC 1




The automatic switch from GPS to VLOC is not immediate, but instead occurs gradually to prevent abrupt CDI changes when coupled to an autopilot. The CDI selection can also be changed manually by tapping CDI.




If you attempt to intercept the approach course at a distance less than 2.0 nm from the FAF, tap CDI to manually switch from GPS to VLOC.
 
Bill.Peyton said:

There are two scenarios when performing an approach. Vectors to final and a full approach. I assume you are having issues with the VTF scenario. When performing a Vectors to final approach, you should load and activate the approach as soon as ATC begins vectoring you to final. You can verify this is active by the magenta extended center-line of the runway. The autopilot should be manually switched to the heading mode from the NAV mode. When you are cleared for the approach, you then activate the Autopilot approach mode, which activates vertical guidance. The GS or GP will only be intercepted if you are below the glide path. At this point, you have received your last ATC vector, and when your are within 1.2 NM of the final approach course, the GPS will auto switch the CDI from Heading mode to LOC. When you hand fly the approach it is essentially the same procedure, but ignoring the A/P activation.​

BTW, when you load an ILS/LOC approach, the GTN loads the LOC frequency in the standby window. You have to manually move the freq. to active.

Hope this helps!

​

From Garmin:​

When does the GTN (Xi) switch the external CDI output from GPS to VLOC ?​

The GTN automatically switches the external CDI output from GPS to VLOC as you intercept the final approach course. When the ILS approach activates and the correct ILS frequency activates in the VLOC window, the GTN automatically switches to VLOC within 1.2 nm left or right of the final approach course. This switch can take place anywhere from 2.0 to 15.0 nm from the FAF.

This illustration shows multiple locations along the approach path and the CDI selection that you can expect: GPS or VLOC. The shaded area depicts where the automatic switch from GPS to VLOC should occur.



GPS to VLOC 1




The automatic switch from GPS to VLOC is not immediate, but instead occurs gradually to prevent abrupt CDI changes when coupled to an autopilot. The CDI selection can also be changed manually by tapping CDI.




If you attempt to intercept the approach course at a distance less than 2.0 nm from the FAF, tap CDI to manually switch from GPS to VLOC.
Click to expand...
Bill,

Thanks but you missed the question I think. This is not a Dynon or AP issue. I cannot get get the GTN to offer the option to "Load" the approach. It only offers to "Load and Activate". It doesn't matter if I load a vector to final or the full approach I never get the option to "Load".
 
I have never had it that I could load & activate but not just load the approach. Have you tried it for a different airport/approach just as a test to see if this is particular to this airport or others behave the same way. In regards to the switch from GPS to ILS, you are on the right track. If you activate the approach while you have an active CDI, then the switch will not take place.
 
Hangar 1271 said:
I cannot get get the GTN to offer the option to "Load" the approach. It only offers to "Load and Activate".
Click to expand...
This would be typical behavior if you have no other flight plan active, since you can't have an approach "loaded" if the rest of the flight plan is blank.
 
mburch said:
This would be typical behavior if you have no other flight plan active, since you can't have an approach "loaded" if the rest of the flight plan is blank.
Click to expand...
Matt,

Great answer! When I entered a flight plan it allowed me to load an approach without activating. Now I'll have to see if it will auto switch when I activate the approach in the proper zone but that won't be for at least another 1-2 weeks. Thanks.
 
Hangar 1271 said:
Matt,

Great answer! When I entered a flight plan it allowed me to load an approach without activating. Now I'll have to see if it will auto switch when I activate the approach in the proper zone but that won't be for at least another 1-2 weeks. Thanks.
Click to expand...
Have you ever used the Garmin PC Trainer Suite ?? - It's a free download

Garmin: PC Trainer Suite for GTN, G500/G600 TXi, GDU 620, GNX 375, GNC 355/355A, and GPS 175 Launcher Updates & Downloads

PC Trainer Suite for GTN, G500/G600 TXi, GDU 620, GNX 375, GNC 355/355A, and GPS 175 Launcher Updates & Downloads
www8.garmin.com www8.garmin.com
Just a thought...
 
You must log in or register to reply here.
Back
Top