VLOC annunciator all the time on a 106A

k9medic

Line Up and Wait
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N Central FL and GTC Bahamas when off work
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ATP-H, CMEL, CSEL, CFI/CFII Airplanes and Helicopters
Just installed a 430W with a 106A indicator during the past annual and today had a chance to go up and fly it a bit.

The autopilot finally tracks the GPS and will hold the course during the approach. When it tries to enter the hold though, all bets are off. I'm guessing that is the limitation between an analog autopilot interfacing with the Garmin.

More curious is the fact that the VLOC indicator on the CDI is always illuminated no matter the selection on the GPS (vloc or gps selection.)

Is this a configuration setting or is this a wiring issue I need to bring back?
 
Sounds like a wiring issue. There are 2 pins on the 430, one for each, VLOC and GPS. The 430 grounds a pin to annunciate one vs the other. Sounds like you may have a short to ground on the VLOC pin.
 
Thanks Jesse. That's what I was afraid of. I believe pins 1 & 2 on the 430W 4001 harness need a better looking at.

BTW, great job on that recent panel in the Mooney.
 
I agree with Jesse... sounds like a wiring issue for the VLOC always issue... perhaps they didn't wire it to the GNS at all, and just grounded the VLOC pin @ the 106A. Does the CDI display course as expected when in GPS mode? It's possible they only wired it to the VHF nav output connector and as such just grounded the VLOC pin to indicate it was always only showing VHF nav.

As to the hold issue... did you have a roll steering converter installed? Otherwise yeah, that's totally not going to do what you hope by having it just track the needles. It'll make slow corrections to chase the needle, but it'll never make crisp turns that way. You'd need something to do the roll steering emulation as heading commands (GDC31, ST-901, G5, GI 275, etc) to get a legacy AP to do that. Without GPSS you'll need to switch to heading mode and manually roll the turns around for the hold and then re-enable nav or apr mode when actually tracking a relatively fixed course.
 
The CDI does display the course as expected. Also tracks the VOR and ILS when in VLOC selection on the GPS.

As for the roll steering, it's old school Century IIB to a radio coupler. I had it selected to the LOC/NORM setting. First attempt is was awful. Second turn we used the heading bug.
 
Yeah, trying to track a hold via nav mode on an analog autopilot is just not going to be any good at all. But that's not to say that the 430W+your Century IIB can't track a hold and do it well, you just need another piece of equipment to handle that through the HDG emulation. I would have suggested a G5+GAD29B or GI 275 as a DG/HSI instead of the GI 106A, another good option would be to pick up a used DAC GDC31 from folks that are upgrading to glass and have that wired in. An older, but working well analog autopilot really gets new life when you add in GPSS.
 
Did 5hy certify the installation? They should have gone through the verification procedure. It’s theirs to fix.
 
Thanks all. Adding more stuff to the plane is not on the table right now. I was very hard pressed to add the 430W. If they had not decommissioned the VOR approach into my home airport, it probably would not have happened since the plane is used to fly to/from the Bahamas 99% of the time.

As far as "certification", I know everything was verified (or so I thought.) Not a big deal for the fix so no issues there. I did the internal configurations for the 430W to talk to the transponder and I wanted to verify before I take it in.
 
I could be missing something here so forgive me if I'm misunderstanding your situation, but you need GPS Roll steering (GPSS) in order for your autopilot to fly a PT or hold, and your radio coupler must be in HDG mode to track the roll steering inputs. The only time you're going to want to use LOC NORM is for an actual ILS or localizer approach. For everything else, you'll want HDG mode.

EDIT: read through your replies a little more carefully. If you did not have an interface such as the GAD29B installed your autopilot is not receiving roll steering inputs and will only be able to track courses. If that's the case, you need to fly holds the old fashioned way for now.
 
Yep. That's what I'm figuring out. No GPSS so I can do it with the heading bug. Easy enough.

Yes, and all while watching a moving map display of your depicted hold, even if it's on an iPad. We tend to forget how far we've come, and how quickly! I'd have absolutely loved the ability to fly a hold this way when I was learning to fly. This is still a high level capability compared to just one or two avionics generations back...
 
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