GFC500 problem

[Pinecone]

BK installs can also have pitch oscillations.

My 252 with KAP-150 does.  Mainly in ALT mode.  It will start to pitch up and down and slowly increase the excursions. If I tap the CWS button, it stops oscillating.

There is some oscillation in VS mode in that it does not hold the VS very well.

[PeytonM]

GFC500 GSA28 servos Service Bulletin TODAY. I wonder if this is what we’ve been waiting for!!

https://support.garmin.com/en-US/aviation/faq/fDr3LoWvVh73y7YNV5WnjA/?keywordSearch=23038

[hubcap]

My KFC200 would oscillate in the climb when you got above ~17,000'. It was a slow oscillation that wasn't particularly disturbing, although it was noticeable. It was worse in the summer when the DA was high.

I have only taken 2 flights so far with the GFC500 but it has been rock solid so far but I have not been above 5,000' yet. Probably tomorrow will take a short X-country to check it out.

[PT20J]

Joey Ferreyra posted this on BeechTalk:

Hi everyone, we've been working the details of this for the past several weeks as Trek has mentioned. While we are pleased many of you enjoy the seamless operation and utility your autopilot provides, we know some have experienced servo issues. We would like to share what we have done to address these concerns to-date, as well as introduce a plan to transition aircraft to the most current production servo.

What we have done
To date, two service bulletins have been published due to specific issues discovered by Garmin. Given these challenges and continued reports from both dealers and customers concerning servos with serial numbers outside the published Service Bulletins, a dedicated team was assigned to evaluate returned servos. As a result, Garmin has implemented several improvements within the current production servo design and manufacturing processes. We are confident these improvements will increase the reliability of the servo.

Moving Forward
Two new Service Bulletins have been published that allows replacement of servos with the most current production version with all the design improvements. If your initial installation occurred before the Fall 2022 timeframe, your aircraft is likely impacted.

For Certified Aircraft Owners with GFC 500, here is the link to the Aviation Service Document Notification: https://support.garmin.com/en-US/aviati ... Nr8uLLUA6/

For Experimental Aircraft Owners with GFC 500X, here is the link to the Service Bulletin: https://support.garmin.com/en-US/aviati ... arch=23038

As an aircraft owner with affected servos, I personally understand the challenges this presents us. I appreciate there are a lot of tasks required to keep our aircraft flying and that this adds another task for us to complete. With this in mind, we are giving you options to help alleviate downtime.

For those with servos in the affected serial number range, you can perform the servo replacement at a time of your choice, pending servo availability, like a regularly scheduled maintenance event. Garmin will prioritize aircraft with the replacement of all servos, should one become inoperative.

We’ve created a single location with instructions on how to locate serial numbers on your displays, compare those to known affected part numbers/serial numbers and instructions for the most efficient next steps to move forward.

The link will soon become available with instructions: Garmin.com/GSA28info

For those that have already paid for servo replacements outside of warranty, please email gsainquiries@garmin.com.

We pride ourselves on the safety, quality, and reliability of our products as well as the service we provide you. Thank you for being a loyal Garmin customer.

-Joey Ferreyra
Garmin Sales & Customer Experience Manager

[ilovecornfields]

I thought I was voted down when I suggested a software change wasn’t going to fix a hardware problem?! Sounds like there were hardware issues after all.

[Ragsf15e]

He didn’t say anything about oscillations.  I wonder if this is addressing some other issue?

[EricJ]

47 minutes ago, Ragsf15e said:

He didn’t say anything about oscillations.  I wonder if this is addressing some other issue?

There've been general reliability issues with Garmin servos for a while.    I suspect they may be solving multiple problems here, or at least I suspect many are hoping so.

[hammdo]

As much as I'd like to add an auto-pilot -- I'm waiting to see how this is all taken care of.  I'm sure it will be fine but I'll have to get on a list and wait -- I'm hopeful that when I do decide, this issues will be resolved first -- or, see if TruTrak 'ever' get's theirs out (since David wired up the TruTrak already)...

-Don

[EricJ]

10 hours ago, hammdo said:

As much as I'd like to add an auto-pilot -- I'm waiting to see how this is all taken care of.  I'm sure it will be fine but I'll have to get on a list and wait -- I'm hopeful that when I do decide, this issues will be resolved first -- or, see if TruTrak 'ever' get's theirs out (since David wired up the TruTrak already)...

-Don

Dynon is in the pipeline too and looks like may be a reality before the Aerocruze ever becomes available again.

[hammdo]

Still, Dynon will need time to sort out their bugs too…

-Don

[kortopates]

I thought I was voted down when I suggested a software change wasn’t going to fix a hardware problem?! Sounds like there were hardware issues after all.

Yep, but the question remains if the hardware changes were to change or improve functionality or improve longevity issues. But we should hear soon.


Sent from my iPhone using Tapatalk

[donkaye]

My servos are all 5G9 series.  Garmin says you don't even have to look up a serial number if yours start with that sequence.  According to Garmin they all need replacement.  I'm reluctant to do it now, since for the past 3 years they have all worked perfectly.  With the number on the bad list, this is going to hurt them a lot.

[Scottknoll]

We just had ours installed. Roll/Ptrim/YD all mod 1. Pitch servo is only one needing replacement. We had pitch oscillations at high speed. Cleaning/lubricating trim jackscrew appears to have fixed it. Smooth as glass now. We still have 21 months of warranty and 5 years to replace pitch servo with coverage under this SB. If we see no issues with our pitch servo, I plan to keep the old one as long as possible. Replacing now doesn’t change my warranty. If I can make it until at least the end of our 2 year new install warranty, we get a new 6 month warranty after exchange. Figure if I make it to the five year mark and swap it then, it’s like having a 5 1/2 year warranty.

[kris_adams]

Not sure if I missed this earlier in the thread but you get a 5 year warranty on the new servos.  That will be nearly 8 years that garmin will have covered them under warranty for me. Mine are working fine and I continue to be amazed at that box, but I will get them done late summer.  

[kris_adams]

I’ve heard there are ~35k servos in the field to be replaced. Glad G has deep pockets to swap them out and pay for the labor to get it done.

[Scottknoll]

Oh, then maybe I misunderstood. I thought it was 5 years to replace qualifying servos for free via the service bulletin. Then 2 year warranty from original install or 6 months from servo replacement, whichever is greater.

[Fly Boomer]

21 hours ago, ilovecornfields said:

I thought I was voted down when I suggested a software change wasn’t going to fix a hardware problem?! Sounds like there were hardware issues after all.

Based on what I have read here and on BeechTalk, I suspect the GFC-500 servos are a bit wimpy for our airplanes (and Bonanzas).  Probably fine for a lighter homebuilt, but maybe they start being not so fine up around 3,000 pounds gross.  If I understand correctly, the servos for the GFC-600 and GFC-700 are more robust, and I don't recall reading about issues with them.  This blurb from AOPA sums it up nicely:

GARMIN ANNOUNCES TWO NEW AUTOPILOTS
AFTERMARKET DIGITAL AUTOPILOT SEGMENT GETS A BOOST

July 18, 2017     By Thomas B Haines

The long-languishing aftermarket digital autopilot segment got a big boost July 18 when Garmin International announced not one, but two new autopilots.  Both share similar features, but are designed for different market segments. The GFC 500 is geared toward lighter general aviation airplanes ...

QED

 

[TrekLawler]

hello everyone,

   I'm sorry for the delay in getting to any questions, as you can imagine the last couple of days have been pretty busy. To answer everyone's questions on the difference between the GFC 500 and 600 servos, the differences are very minimal, if you were to take them apart you'd notice the same motors and a lot of the same components. the GFC 500 servos are very capable of flying twins if needed.

   as for the questions on the service bulletin we just issued, I can't into all of the internal details, but we've been studying the returns on the servos that have had problems in the field and we basically were not happy with the life of them, so our engineering team made a number of internal changes and it was decided that we wanted to get them all replaced in the field. this does nothing for extending any original new install 2 year warranty, but since there is a finite number of theses servos on hand we're needing to schedule these with our dealers. but are offering everyone 5 years to get these replaced at no charge, in essence a 5 year warranty. so if your plane is flying OK I'd suggest taking advantage of this extended program and waiting as long as possible to get them replaced.if you are having hardware problems then you can get with your Garmin dealer and we will replace all of the -11 servos as well as any non mod 1 -21 part number units.

I've been asked if this will address any oscillation issues as well, I seriously doubt it as these changes internally in the servo does nothing to change the gain or software of the system. this mod is simply addressing some component failures we've seen and we want to make sure you have quality servos for many years to come.

 

please let me know if there are any questions. I'm spending quite a bit of time on forums for the next couple of days addressing questions.

[rbp]

On 5/5/2023 at 12:26 AM, Ragsf15e said:

He didn’t say anything about oscillations.  I wonder if this is addressing some other issue?

i wrote @TrekLawler yesterday about this and he said "I'm sorry no, I doubt it"

[rbp]

3 minutes ago, rbp said:

i wrote @TrekLawler yesterday about this and he said "I'm sorry no, I doubt it"

if only i had read to the end before posting!

[PeytonM]

The whole 5 year timing and warranty was pretty confusing; thank you, Trek, for clarifying this in your post.

However, I remain VERY disappointed that Garmin seems no closer to resolving the oscillation issues since the first post on this thread a year ago. 

[Mooney in Oz]

For the info of any Mooney aircraft fitted with a G5 unit,  I just copied this post from BT:

“Also, working with my avionics shop to have my affected servos replaced, they said not to update to the latest G5 software yet. Apparently, about 1/2 the airplanes that got the software update now have a failed servo due to the tighter servo tolerances in the software.”

I’ll add to that suggesting those with a G3X with a G5 to also not do the update until we know more.

@TrekLawler Are you able to comment on this?

 

[PeytonM]

Oh great! I already had software updated…

[Mooney in Oz]

6 minutes ago, PeytonM said:

Oh great! I already had software updated…

Sorry Peyton, I only just read this on BT before posting.

Hoping that Trek can shed more light on this and that yours will be fine.

[PeytonM]

I thought you HAD to do either do the software update or disable autotrim, which knocks out the A/P. Not much of a choice. I cannot believe Garmin would not have known this. “Unintended consequences!”