G5 and GFC-500, this isn’t supposed to happen right?

[masloki]

So, I haven’t gotten a successful approach in behind this autopilot, I think. This weekend, went out and flew an ILS and I couldn’t get it to follow the GS down so hand flew it. Hmm. Set up for an LPV and it just held course and altitude with this indication.

If you were going to troubleshoot things…where would you look? Driven by an Avidyne IFD-540 with a GAD-29B in the background.

 

[asicer]

GS is white and the FD bars are still on the horizon. Seems that the autopilot didn't think that it captured the glide slope.

 

[dmspilot]

So, I haven’t gotten a successful approach in behind this autopilot, I think. This weekend, went out and flew an ILS and I couldn’t get it to follow the GS down so hand flew it. Hmm. Set up for an LPV and it just held course and altitude with this indication.
View attachment 100276
If you were going to troubleshoot things…where would you look? Driven by an Avidyne IFD-540 with a GAD-29B in the background.

You said you set up an LPV but it shows a LOC/GS armed annunciation in white. So that means it's trying to capture an ILS, not an LPV, is it not?

 

[dmspilot]

GS is white and the FD bars are still on the horizon. Seems that the autopilot didn't think that it captured the glide slope.

He's trying to capture an LPV though, so the wrong mode is armed.

 

[masloki]

Activated and on the LPV. 2600 is the FAF and I am 0.2 nm out. Autopilot is looking for something else though not sure why.

 

[Groundpounder]

Did you arm approach mode?

 

[masloki]

Yes.

Did you arm approach mode?

 

[Groundpounder]

Yes.

Huh, ok. The ADI looks like it's searching for a loc signal, but the HSI looks like it's in GPS mode. The needles on the HSI should be green if you're trying to do an ILS

 

[MooneyDriver78]

I’d guess the Avidyne is not properly configured for the correct protocol on the serial interface.

 

[masloki]

I’d guess the Avidyne is not properly configured for the correct protocol on the serial interface.

You wouldn’t happen to have a recommendation for the config? Out of the avionics shop it was throwing a 429 error, and a config change cleared the error but doesn’t seem fixed still.

 

[MooneyDriver78]

You wouldn’t happen to have a recommendation for the config? Out of the avionics shop it was throwing a 429 error, and a config change cleared the error but doesn’t seem fixed still.

In Garmin world, they use MapMx-F2 for RS232, don’t know how 429 is configured.

 

[bid shader]

So, I haven’t gotten a successful approach in behind this autopilot, I think. This weekend, went out and flew an ILS and I couldn’t get it to follow the GS down so hand flew it. Hmm. Set up for an LPV and it just held course and altitude with this indication.
View attachment 100276
If you were going to troubleshoot things…where would you look? Driven by an Avidyne IFD-540 with a GAD-29B in the background.

In addition to what others noted on the HSI being in GPS mode but the AI looking for a LOC, the indications from the AI are that the AP isn't actually engaged here, right? The FD bars on the AI are hollow which means it's in FD mode only and not AP. Also there is no AP annunciation in the top status box.

 

[masloki]

Yes, at this point AP is off but flight director is on. I don’t think there is any reason AP/FD and HSI should be different when GPS is tracking the LPV. But, if you want to see the full KENW RNAV 7L approach, I’ve posted a video here:

The audio sync is a little off, and the camera didn’t pick up the GPS display well, so you’ll have to trust me on that one.

 

[Gary Ward]

Yes, at this point AP is off but flight director is on. I don’t think there is any reason AP/FD and HSI should be different when GPS is tracking the LPV. But, if you want to see the full KENW RNAV 7L approach, I’ve posted a video here:

The audio sync is a little off, and the camera didn’t pick up the GPS display well, so you’ll have to trust me on that one.

Please don't take this as a insult, it is just my observation.

It looks look the lay out of your stack could be a little awkward? It seems the GPS could be a little higher in your stack to make it easier to operate?

My GPS is up top with the GFC500 right under it since the I use the GFC all the time for my heading and altitude bugs even when not using the AP.

Having my GPS up high allows me to rest my finger tips on the ledge for when in turbulence.

 

[bid shader]

I haven't watched your video yet, and I'm far from an expert (I fly a GFC500 but with a Garmin Navigator, but I'm just a pilot), but does the issue only happen when the navigator autoswitches from GPS to VLOC? Avidyne navigators I think autoswitch from GPS > LOC whereas my GNS530W requires pilot intervention to do that. I recall seeing a couple of forum posts about a year ago where people that had the GFC 500 installed with an Avidyne navigator were experiencing the AP switching into default heading mode (Pitch or Roll) when the Avidyne navigator made the switch. I'm a new user here and can't post links yet, but previous posts on other forums referenced s3.3.2.2 of the G5 pilot's guide:

If the information required to compute a flight director mode becomes invalid or
unavailable, the flight director automatically reverts to the default mode for that axis.
A flashing yellow mode annunciation and annunciator light indicate loss of sensor or
navigation data required to compute commands. When such a loss occurs, the system
automatically begins to roll the wings level (enters Roll Hold Mode) or maintain the
pitch angle (enters Pitch Hold Mode), depending on the affected axis. The flashing
annunciation stops when the affected mode key is pressed or another mode for the
axis is selected. If after 10 seconds no action is taken, the flashing annunciation
stops. The flight director is automatically disabled if the attitude information required
to compute the default flight director modes becomes invalid or unavailable.

Is this the behavior you're seeing? I think you would have gotten a yellow GPS indication on the G5 at some point if so. If this is the case it may simply be Garmin's "normal" ability to interface with equipment from other manufacturers. Potentially selecting approach mode earlier (prior to the switchover from GPS > LOC) may help?

 

[masloki]

Please don't take this as a insult, it is just my observation.
It looks look the lay out of your stack could be a little awkward?

Not an insult and more than a little awkward. At some point I will figure out where the GPS can be moved to, but it isn’t possible to move it vertically. The Mooney steel frame support is behind that stack. Thankfully I don’t fly prop full forward much or I’d never be able to dial the comm in turbulence.

but does the issue only happen when the navigator autoswitches from GPS to VLOC? Avidyne navigators I think autoswitch from GPS > LOC whereas my GNS530W requires pilot intervention to do that. <snip>

A flashing yellow mode annunciation and annunciator light indicate loss of sensor or
navigation data required to compute commands. When such a loss occurs, the system
automatically begins to roll the wings level (enters Roll Hold Mode) or maintain the
pitch angle (enters Pitch Hold Mode), depending on the affected axis. <snip>

I haven’t flown it enough to see that problem - newish autopilot and most of my instrument flying is GPS approaches. My home field ILS is notam’ed out, 12 months now, so I had to go out of the way to try an ILS. For this flight I manually switched from GPS to ILS and back to be sure of when the switching occurred. And, no yellow annunciations on any instruments. Honestly, that is a bigger frustration as the system isn’t working correctly but no errors are being displayed.

 

[bid shader]

Frustrating. I can tell you once you get it sorted out you will be very happy - I have the GFC500 with an older Garmin GNS530W and it is rock solid - flies ILS & RNAV approaches very well.

Referring back to your earlier post about seeing a 429 error at the Avionics shop, I did see this post earlier (last post in the thread is potentially relevant):

http://forums.avidyne.com/ifds-and-gfc-500_topic1927.html

 

[Salty]

Not an insult and more than a little awkward. At some point I will figure out where the GPS can be moved to, but it isn’t possible to move it vertically. The Mooney steel frame support is behind that stack. Thankfully I don’t fly prop full forward much or I’d never be able to dial the comm in turbulence.

I think he meant putting the avidyne above at least the audio panel, and maybe even the gfc500 head

 

[Salty]

Frustrating. I can tell you once you get it sorted out you will be very happy - I have the GFC500 with an older Garmin GNS530W and it is rock solid - flies ILS & RNAV approaches very well.

Referring back to your earlier post about seeing a 429 error at the Avionics shop, I did see this post earlier (last post in the thread is potentially relevant):

http://forums.avidyne.com/ifds-and-gfc-500_topic1927.html

If that’s true it’s a nail in the coffin for the avidyne.

 

[masloki]

I think he meant putting the Avidyne above at least the audio panel, and maybe even the gfc500 head

I agree and that's how I read it. Of the 3 boxes, the Avidyne is the longest/deepest box and there is a steel support brace that runs directly behind all three and cabin side of the windshield. I can't swap it with any others because of that brace. One of the reasons avionics shops complain about working on Mooneys. On the upside, I have the original windshield which means easier access to the back of the panel from outside the plane.

Support brace with compass attached.

 

[Salty]

I'm very familiar with the brace, I fly a M20C. I was not aware the 750 was THAT long.

 

[MooneyDriver78]

Support brace with compass attached.

I hate the compass attached to the brace, if doing any panel upgrade, you might consider replacing it with a panel mount.

 

[Tantalum]

Set up for an LPV and it just held course and altitude with this indication

That photo doesn't seem right at all. See below, this is an RNAV18 LPV approach I did on AP. Notice the annunciators on the G5.. and notice the mode on the GFC500 (below the comm nav stack). This is what you want to see. It does not appear you were in the right mode and things didn't quite capture and work out as planned

Some other tips..
-you have to actually be on a course to intercept the localizer for it to capture that and steer the plane left or right
-it won't capture the GS from above
--did you remember to activate the approach? Are you sure you had it on "GPS LPV" CDI and not "VLOC" ?
-make sure you know how to use the Flight Director.. otherwise you may follow it to oblivion


PS, I know the G5 letters are tiny, but it says, from left to right, "GPS" "AP" "GP"

 

[Tantalum]

^yes, I had to screenshot my own picture on the photo.. the file size was too big

 

[mdpilots]

I know this is over a year old, but I'm wondering if others have experience this and what was the resolution. I have about 30 hours on my GFC 500 w/ GI 275s and GNS430W. I've successfully flown ILS and LPV approaches. A few days ago I was cleared for an RNAV LPV and then was cleared to bypass the IAF direct to the IF, which is a 90 degree turn to final. I had the approach activated in the 430, CDI was on GPS, HSI showed GPS / LPV in magenta. My 275 autopilot annunciator, however, showed exactly like the OPs - LOC and GS were white (armed), as if I were on an ILS approach. The plane properly turned to capture the final inbound course. The GP indicator came alive and was magenta, indicating a GPS approach with vert guidance. However, when the GP indicator centered, the plane did not capture the glide path, but held altitude. I quickly hit APR to turn it off and hit APR again to reengage. The plane then began to follow the glidepath down and the annunciator changed to GPS / GP in active and the LOC / GS disappeared.

Anyone experience this with a 430W or 530W? The original post seemed to point to the Avidyne.