Garmin 275 & 175 with KAP 140 autopilot

[TBalch]

I have a GI 275 installed as an HSI, along with a GPS 175 navigator, and I'm trying to learn how to utilize GPSS mode when flying approaches with my KAP 140 autopilot engaged.

The Garmin pilot's guides provide virtually zero information on this subject, so I'd like to communicate with someone who is familiar with this combination of equipment, or be referred to any available literature on the subject.

Thanks.

 

[midlifeflyer]

Did your installer enable this capability? GPSS is not native to the KAP 140. Before the integrated GFC 700, the G1000 in Cessna and Diamonds were coupled with a KAP 140. They do not have GPSS capability.

If your installer enable the capability, it should work like any other GPSS add-on to an analog autopilot. On the GI275, there is a HDG/GPSS toggle. Toggle to GPSS. Put the KAP 140 in HDG - not NAV - mode.

Basically, what GPSS mode in the 275 does is, convert commands from your GPS into heading instructions for your autopilot.

 

[TBalch]

Yes, midlife, he did, and I’m familiar with the GPSS toggle.

Are you familiar with this combination of avionics and A/P?

 

[midlifeflyer]

Yes, midlife, he did, and I’m familiar with the GPSS toggle.

Are you familiar with this combination of avionics and A/P?

I have not flown that specific GI275-GPS175-KAP140 combo. Just commenting based on the the way it works in the other 8-12 combinations of analog AP and GPSS I have flown or taught in (avionic transitions is probably 80% of what I do these days with aircraft owners). So far, they have worked pretty much the same in this respect. The GPS175

So, have you been placing the 140 in HDG mode? Are you getting GPS steering?

Or, since you mention approaches, are you asking about when or whether to switch to APR mode on the 140? Laterally, it's not necessary (it would be if the approach was LOC based, but that's not the GPS 175), but since GPSS is lateral, you will need APR mode for the AP to capture the glidepath. Or are you asking about things like procedure turns? You need to be in GPSS/HDG mode to accept turn instructions from the GPS 175.

The problem you are having finding applicable materials is precisely because there are so may potential combinations. GPS 175 vs GTN 750 is irrelevant, PFDs tend to be relatively consistent, even with different manufacturers, but APs can be very different. You kind of have to put things together yourself from separate bits and pieces.

 

[TBalch]

Thanks, midliife.

What's the best way to communicate with you? An e-mail, or a conversation on this Forum?

 

[midlifeflyer]

Thanks, midliife.

What's the best way to communicate with you? An e-mail, or a conversation on this Forum?

You are welcome to PM me, but the real answer is training with a CFI who understands this stuff. It may not take much but depending on what you’ve flown before, some is usually warranted. When GPS came along, “easy to fly but difficult to set up” was a semi joke. It’s the rare person who can train themselves to IFR proficiency with new modern equipment.

BTW, I think the closest I’ve flown to your setup was in a Cirrus G1. The owner upgraded to a pair of GI275s and replaced one of the 430s with a GTN650. Kept his STEC autopilot (which I think had its own GPSS toggle).