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Rich wrote: ↑Tue Apr 16, 2019 2:10 pm Lee, is your G1000 WAAS? If not, LNAV is what I would expect to see for any GPS approach.

Rich, thanks. I read too much into the OP.

TJS wrote: ↑Tue Apr 16, 2019 2:27 am I have been having trouble with the KAP140 as it behaves fine in NAV mode for cruise flight, but I haven’t been able to get it to fly a GPS approach properly. When flying the GPS approach I get to the IAF with the KAP140 in NAV mode; in the approach it tracks the first leg and I set APR mode. Once it turns to final the G1000 indicates that it has changed nav source(from terminal to LNAV) and the KAP140 flashes looking for new input, this where I get confused. I am not sure why the G1000 indicates a change in nav source and I suspect that is why the KAP140 quits. Is there something I am missing or a something on the G1000 that is not right?

Just try to leave it NAV mode until you pass FAF and then press APR. Be sure to manually set appropriate descent rate and minima since I guess you don't have WAAS.

The Honeywell B/K manual tells you to press APR to intercept the localizer. This usually works but my KAP 140 seems lazy to me. Sometimes it will overshoot or wander and I use CWS to nudge it back on course. Other times my APR indication will start flashing on the display, no idea why. If I push APR again it usually wakes up and re-captures. Much better than not having an autopilot, but you really have to keep tabs on the KAP 140.

Yes, not only loaded but also activated. I now fly behind a 430W and that has another "Gotcha". Unlike the G1000, when ILS is loaded into flight plan, the frequency is placed in standby slot and has to be manually switched to active position. I have missed this, too.

Rich wrote: ↑Tue Apr 16, 2019 2:15 pmI don't know that it applies to the G1000, but I would assume so: Is the approach Loaded or is it Activated? It needs to be the latter to fly it.

I almost NEVER "activate" the approach, since that always creates a direct path to the Initial Approach Fix (IAF) -- which is rarely flown.

Instead, it's better to just "load" the approach, while awaiting ATC instructions to either:
- fly to a waypoint somewhere along the approach course (which might be the IAF) using autopilot in NAV or APR mode, or
- operate in HDG mode while being radar vectored to the approach. In the case of a GPS approach, when being vectored by ATC you may need to use the "Activate Leg" so that the particular approach segment your aircraft will intercept has been activated beforehand. With an ILS/LOC approach, loading vectors-to-final will likely give you a course to intercept, and you'll arm the autopilot to APR only after ATC has cleared you for the approach.

I believe my problem is with the G1000. It indicates that it has "changed nav source" when it makes the switch from term to LNAV.
I have activated the approach and the KAP140 it is tracking the approach as is should. Once the G1000 "changes nav source" it dumps the connection to the KAP140, as it should. I just dont know why it "changes nav sources" without my prompt. with a stiff crosswind it can be a lot of button pushing to get the KAP140 set up again.

I’m one mock checkride away from my IFR check and have been flying a lot of approaches in the last few months. I have seen a lot of the same as reported here and cheat a lot with CWS to fly the approach ( especially RNAVs) correctly. My KAP 140 never makes std rate turns (usually 60-70% of std) so I typically use CWS to start turns when the G1000 annunciates that so as not to overshoot turns. I am going to check during tomorrow’s flight but I think the A/P disengages APR mode when the FAC is “captured”. You have to reengage APR mode at that point. Happens on every RNAV I’ve flown. The more severe problem for me is inside the FAF. Too frequently, especially with a gusty quartering headwind, the A/P can wander off and I have to be ready to correct with CWS. I was told the GFC700 does a much better job.

40flyer wrote: ↑Tue Apr 23, 2019 7:29 pm Too frequently, especially with a gusty quartering headwind, the A/P can wander off and I have to be ready to correct with CWS.

Partially it depends on aircraft speed and angle between actual heading and final course but from my experience gusting crosswind on capturing makes the toughest challenge for KAP140. Once it captures localizer it keeps it sufficiently good.

40flyer wrote: I was told the GFC700 does a much better job.

Definitely.

I just looked in my log book and have done over 40 approaches in actual with nearly everyone of those an ILS (I did not have WAAS in my DA42 and the autopilot was a KAP140). I can't recall a single ILS approach that gave me problems with the localizer (although I did have one which I had to go missed because of a glide slope issue). Of the several hundred approaches I have done (most of which were practice approaches) in the DA42, I rarely if ever had to use CWS. I wonder if this is a difference between the way the DA42 flies and the way your DA40 flies?

40flyer wrote: ↑Tue Apr 23, 2019 7:29 pm I’m one mock checkride away from my IFR check and have been flying a lot of approaches in the last few months. I have seen a lot of the same as reported here and cheat a lot with CWS to fly the approach ( especially RNAVs) correctly. My KAP 140 never makes std rate turns (usually 60-70% of std) so I typically use CWS to start turns when the G1000 annunciates that so as not to overshoot turns. I am going to check during tomorrow’s flight but I think the A/P disengages APR mode when the FAC is “captured”. You have to reengage APR mode at that point. Happens on every RNAV I’ve flown. The more severe problem for me is inside the FAF. Too frequently, especially with a gusty quartering headwind, the A/P can wander off and I have to be ready to correct with CWS. I was told the GFC700 does a much better job.

Great rating to get!
Best wishes on your check ride! When is it?