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3GX Auto pilot wiring

Mark Browning

Active Member
Can any one give some advice with a question i have with 3GX auto pilot TOGA switch wiring when using the GMC507

Page 27-8 on the install manual clearly shows pin 10 on the GMC507 connecting directly to the TO/GA
switch .. That bits simple but my question is

why do Garmin also say there is an " Optional " connection to the GTN to any discreet input configured for Remote go around

What are the benefits of making the additional connection to GTN650 ? over just wiring in pin 10 to the GMC507

0TRhMd6e5Hen3goDMv1EQnGYw
 
I don’t have this setup so my memory may be faulty, but I think this connection re-starts auto-sequencing on the 650. Otherwise, you need to tap the 650 screen to tell it to start missed approach guidance.
 
TO/GA Switch

Can any one give some advice with a question i have with 3GX auto pilot TOGA switch wiring when using the GMC507

Page 27-8 on the install manual clearly shows pin 10 on the GMC507 connecting directly to the TO/GA
switch .. That bits simple but my question is

why do Garmin also say there is an " Optional " connection to the GTN to any discreet input configured for Remote go around

What are the benefits of making the additional connection to GTN650 ? over just wiring in pin 10 to the GMC507

0TRhMd6e5Hen3goDMv1EQnGYw

The TO/GA button serves two purposes in the case of a go around on an instrument approach. The connection to your GMC 507 cycles the autopilot vertical and lateral modes, to set you up for climb out and the missed approach procedure. The connection to your GTN cycles the flight plan to the first waypoint in the missed approach procedure, depending on where you are on the approach. The GTN flight plan sequence would otherwise terminate at the runway.

Thanks,

Justin
 
The TO/GA button serves two purposes in the case of a go around on an instrument approach. The connection to your GMC 507 cycles the autopilot vertical and lateral modes, to set you up for climb out and the missed approach procedure. The connection to your GTN cycles the flight plan to the first waypoint in the missed approach procedure, depending on where you are on the approach. The GTN flight plan sequence would otherwise terminate at the runway.

Thanks,

Justin

Thanks Justin
That is really helpful and makes sense. I am using the the February 2019 revision S GTN install manual, and just starting on the wiring.
I'm struggling to understand discrete inputs? ( i know i have a lot to learn:rolleyes: ) Page 5-20 shows a number of discrete inputs pins 16, 36,37,38,1,11 on P1001 connector.... am i correct in thinking i configure one of these to perform the to/ga input ?

i don't suppose there's a book on " Discrete inputs for Dummies ":D

Thanks for your help
Mark
 
Discrete Configuration

Thanks Justin
That is really helpful and makes sense. I am using the the February 2019 revision S GTN install manual, and just starting on the wiring.
I'm struggling to understand discrete inputs? ( i know i have a lot to learn:rolleyes: ) Page 5-20 shows a number of discrete inputs pins 16, 36,37,38,1,11 on P1001 connector.... am i correct in thinking i configure one of these to perform the to/ga input ?

i don't suppose there's a book on " Discrete inputs for Dummies ":D

Thanks for your help
Mark

Mark,

You are on the right track, you will configure one of these for Remote Go Around and connect it to your TO /GA switch. When the TO / GA switch is pressed, it grounds the discrete input on the GTN to trigger the desired flight plan sequencing. This is an example of an Active Low Discrete Input. It becomes active when the input is grounded.

Thanks,

Justin
 
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