Expected behaviour with TruTrak

[1bigdog]

Hi Experts

I have a G3X touch with GTN 625 and a TruTrak Gemini.
I was out practicing an RNAV missed approach with a friend who has a similar stack except with Garmin AP. When he pushes the TOGA button in his aircraft it pitches up to 5 degrees and proceeds to the hold as expected. When we tried on mine we didn't note it pitching up and we didn't see the GTN change it's sequence to proceed to the hold. (Now, please be gentle. I'm not in any way an IFR expert, just learning).

On the ground I can see the TOGA indication on the G3X when I push the TOGA button (which is DPST - wired as per the diagrams). I don't see an obvious indicator to see the GTN acknowledge the TOGA activation. So I guess I have a few questions.

1. Does the Garmin stack behave the same as one with a TruTrak AP?
2. Is there a method to test the AP behaviour on the ground on the G3X (since that would instigate the command to the AP - and yes, the G3X is configured for the 5 degree pitch up on TOGA)?
3. Is there a method on the ground to confirm GTN behaviour?

It should be noted that my overall configuration did everything else correctly into the approach, to the fixes, into the hold and evetually capturing the glidepath.

Thanks for any insights.

 

[uk_figs]

I am no expert on the G3X or GTN 625 but on my setup with the GNX375 and the TruTrak Vizion the TOGA function does not drive the AP in missed approach mode, you have to be coupled in GPSS mode on the LPV glide slope and then briefly press the ALT button on the TruTrak and the AP follows the current track and climbs at 500 ft/min, when the navigator hits the missed approach point and you select going missed the AP will then fly the missed approach procedure in GPSS mode and fly the hold procedure. I am a new instrument pilot so I hope this helps. Check the TruTrak manual.
Figs

 

[1bigdog]

I am no expert on the G3X or GTN 625 but on my setup with the GNX375 and the TruTrak Vizion the TOGA function does not drive the AP in missed approach mode, you have to be coupled in GPSS mode on the LPV glide slope and then briefly press the ALT button on the TruTrak and the AP follows the current track and climbs at 500 ft/min, when the navigator hits the missed approach point and you select going missed the AP will then fly the missed approach procedure in GPSS mode and fly the hold procedure. I am a new instrument pilot so I hope this helps. Check the TruTrak manual.
Figs

Hi Figs. Good hint to look at the manual. It didn’t even occur to me since this is very specific, and frankly I’m new to these concepts as well. But there is a specific refernce about the missed approach in the Gemini manual similar to yours where you just need to toggle the control up or down and will initiate the climb while still remainng coupled. That said the difference here is that the G3X provides the TruTrak a flight director. Since everything else followed the flight director perfectly I’ll need to check why it ignores this. When I get to the hangar I’ll start with a ground check if the fd command bars rise when TOGA is pushed.
The other checks I can do are to see if the GTN responds to a stuck button (if I hold the TOGA button for 30 seconds) and then check if the “remote go around“ function was enabled in the discrete input configuration. I don’t remember doing that and it’s not documented so it would have been missed.
Cheers