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Larkrv10
10-20-2016, 11:21 AM
Hey all, yesterday shortly after engaging the A/P, while tracking the heading bug and holding altitude, the little triangular lights built into the face of the Garmin GMC 305, started to flash intermittently. I shutdown the A/P electrically using the VPX (G3X Touch) and then turned it back on to no avail.
This is the 2nd time this has happened. After the first time I emailed the Garmin guys, but they didn't know either what was up. During the next flight the lights operated normally again until now. Called Stein yesterday and he wants me to try to video the "light show".
Just wondering if anyone else has had this happen? Odds are it won't happen again for a while to video but who knows?
Rick
#40956
Southampton, Ont

MarkW
10-20-2016, 11:44 AM
You did not state if the AP continued to work properly or if it disengaged with a tone.
What is the indicator on the G3X showing as status for the AP.
I have had a couple of times that I move the plane quicker than was needed for the AHARS to calibrate. On those times I would get the indicator on the PDF showing the AP was inop and I only got a tone when trying to activate the AP.
Part of my IFR checklist now is to engage AP on the ground to make sure it works. Would hate to be on a 3 hr CC IFR with no AP.
I did not notice if the lights flashed on the GMC when that occurred but I think it did.

Icarus
10-20-2016, 01:16 PM
Is it on any sort of dimming circuit?

Zuldarin
10-20-2016, 01:36 PM
Hi Rick, your post reminded me that I have a similar issue. Occasionally the lights on my GMC305 will all cycle off and then back on as if power was being cycled. Since this is just a controller and not the actual autopilot nothing changes with regard to the flight but it does make me think I might have a loose power or ground wire. I haven't had a chance to do more troubleshooting so no answers for you.

Darin

Larkrv10
10-20-2016, 04:44 PM
You did not state if the AP continued to work properly or if it disengaged with a tone.
What is the indicator on the G3X showing as status for the AP.
I have had a couple of times that I move the plane quicker than was needed for the AHARS to calibrate. On those times I would get the indicator on the PDF showing the AP was inop and I only got a tone when trying to activate the AP.
Part of my IFR checklist now is to engage AP on the ground to make sure it works. Would hate to be on a 3 hr CC IFR with no AP.
I did not notice if the lights flashed on the GMC when that occurred but I think it did.

Mark, yes the A/P did continue to operate (heading bug and altitude). There was no indication on the G3X that anything was wrong or the A/P was inop.
Rick

Larkrv10
10-20-2016, 04:50 PM
Is it on any sort of dimming circuit?
Yes the 305 is on a Flight Data Systems LC50 dimmer.

Larkrv10
10-20-2016, 04:55 PM
Hi Rick, your post reminded me that I have a similar issue. Occasionally the lights on my GMC305 will all cycle off and then back on as if power was being cycled. Since this is just a controller and not the actual autopilot nothing changes with regard to the flight but it does make me think I might have a loose power or ground wire. I haven't had a chance to do more troubleshooting so no answers for you.

Darin

Darin, my lights were switching on/off, every last one of them. I am now wondering if the lighting controller I mentioned previously has something to do with it.
Thx

Zuldarin
10-20-2016, 08:33 PM
Darin, my lights were switching on/off, every last one of them. I am now wondering if the lighting controller I mentioned previously has something to do with it.

I'm certainly not a good person to answer that question but I don't have a lighting controller on mine and all lights go out and then come back on occasionally as if there were some sort of power cycle. It's hard to catch but every once in awhile I will see the lights blink and can just barely catch it.