Trouble with Garmin G5 localizer alignment

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MJR Pilot

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MJR Pilot
Curious if others with Garmin G5s are having this issue: I currently have dual G5 PFD and HSI set up and Garmin 430W. Have flown a few dozen approaches with no issues. However, I recently flew a couple approaches in VMC where the final approach course displayed by the G5 CDI did not align with the runway. KBDR RNAV 29 - I was perfectly aligned with the runway, but the CDI final approach course indication was a full dot to the left. Same with KAVP ILS 22 - perfect visual alignment with the runway, yet the localizer was a full dot to the left. And this is happening throughout the entire final approach segment - not just on short final. And as I said earlier, for most approaches the CDI has aligned with the runway, but these 2 instances have left me a bit wary of relying on the G5s in low IFR. I'm going to contact Garmin directly, but we all know that can take a while. Curious in the interim if anyone has experienced similar issues or has any thoughts. Thanks as always.
 
How much wind was there that day? It can be very easy to think you're not aligned with the runway, but in fact you are due to there being a significant wind correction angle.
 
Calm wind. I flew the ILS last night - perfectly aligned with the runway visually, but localizer on G5 was a full dot to the left. Had I followed that localizer course and not had visual contact with the runway, I estimate I would have ended up a few hundred feet to the left of the runway once I reached DA. Scary thought.
 
This happened to me with my old CDI that I had. I understand what you are saying. I would fly an approach in visual conditions and if I aligned myself with the runway the needle would be one to two dots to the left. If I aligned the CDI needle centered then I would be heading off runway centerline and by the end of the approach I would have been well off centerline. Unfortunately I do not have an answer for you since instead of fixing it I upgraded my panel to include a G5 HSI like you have but mine works perfectly. It may need a calibration that Garmin can help you with or there may be an issue with the GMU11 magnetometer.
 
This is just how the approach is. A lot of approaches you don’t look super aligned with the runway in VMC.

It wouldn’t matter if it was a G5, steam gauge, or anything else.
 
Follow the CDI down to mins and see where you are at that point. If it as far off as you seemed that you were further out, then there is an issue.
 
Do it with 2 onboard. Once your head comes out of the cockpit you don't want to be switching back and forth.
You fly the plane to the ground, your copilot records the readings.
 
KAVP Localizer RWY 22 is offset 1.7 degrees to the left from the runway per Jepp.
 
I think you are doing this backwards. Fly the CDI and see where you wind up. I don't think you can necessarily tell if you are aligned with the final approach path by looking out the windshield, accounting for approach course alignment and crab angle.

One thing you can check is your GPS CDI indication against your G5. They should read the same. I'm not sure it's possible for the 430w and G5 to indicate different CDI indications.

FWIW, my G5s appear to accurately reflect what's on the 430W. LNAV horizontal tolerance us in the low tens of meters.
 
Do you have another Nav/CDI to compare while on final?
 
Thanks everyone for the thoughts. I am planning to re-fly KAVP ILS 22 in the next couple weeks (in VMC). I'll plan to fly the G5 CDI down to mins and see where I end up. Will also compare this to (1) the 430 CDI and (2) I'll also set up NAV 2 (old steam gauge, but it works) to track the localizer - will check how this compares to the G5 CDI. Will report back. Thanks again.
 
MJR Pilot said:
Thanks everyone for the thoughts. I am planning to re-fly KAVP ILS 22 in the next couple weeks (in VMC). I'll plan to fly the G5 CDI down to mins and see where I end up. Will also compare this to (1) the 430 CDI and (2) I'll also set up NAV 2 (old steam gauge, but it works) to track the localizer - will check how this compares to the G5 CDI. Will report back. Thanks again.
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In aircraft with dual nav receivers and indicators, its good SOP to tune both to whatever approach you are doing as a form of redundancy.
 
Groundpounder said:
In aircraft with dual nav receivers and indicators, its good SOP to tune both to whatever approach you are doing as a form of redundancy.
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Yes, good point. I normally tune NAV 2 to identify FAF on the localizer course, but thats done easy enough using GPS. Will tune this to localizer going forward.
 
Please don't take this as an insult, but it dawned on me, that 'might' happen if you forget to switch to VLOC mode, thus your CDI would show a GPS derived course instead of the actual localizer signal?
 
Jim Carpenter said:
Please don't take this as an insult, but it dawned on me, that 'might' happen if you forget to switch to VLOC mode, thus your CDI would show a GPS derived course instead of the actual localizer signal?
Click to expand...
Jim Carpenter said:
Please don't take this as an insult, but it dawned on me, that 'might' happen if you forget to switch to VLOC mode, thus your CDI would show a GPS derived course instead of the actual localizer signal?
Click to expand...
No insult taken :). The CDI was set to VLOC mode. also note this happened to me on KBDR RNAV 24 and CDI was appropriately set to GPS. Will keep the group posted.
 
A 1.7 degree offset localizer will seem way off visually.
 
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