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Garmin Autopilot SERVICE ALERT 22112

NTex

Well Known Member
Hi all -

Came across this for certified installs, but it appears that it may affect the RV fleet as well. Garmin notes that an experimental service bulletin will be out soon.

I think most RVs with the GFC500 autopilot use the ray allen servo, unclear based on the description if that's the "third party trim system" or not.

Heads up!


Hi everyone, an issue has come to our attention for aircraft with either the GFC 500 or Garmin autopilot for Experimental Aircraft with the Garmin GSA 28 pitch trim option or a third-party trim system installed.

Here’s the GFC 500 Service Alert: https://atlaske-content.garmin.com/file ... 630332.pdf

A situation has been discovered that can cause an uncommanded pitch trim runaway event upon initial autopilot engagement.

While we work to field the final resolution with software, the autopilot should not be used unless the electric trim feature has been disabled for certified aircraft and the autopilot automatic trim feature is disabled for experimental aircraft.

For GFC 500-equipped aircraft, this requires your Garmin dealer to follow a Service Bulletin that has been made available to them.

While a Service Bulletin will be released soon that addresses the Garmin Autopilot designed for Experimental Aircraft, please find links to the appropriate Installation Manuals below to reference instructions for disabling the automatic trim feature for each respective system.
 
Looks like it's not safe to use some G500s. For Experimentals it says Service Bulletin 22112 but a search on the Garimin site takes you to this same Service Alert 22109 Rev A

GFC 500 Autopilot Systems with Optional Pitch Trim Installed using STC SA01866WI, Master Drawing List, Revisions 1 through 76 are affected.

An un-commanded automatic pitch trim runaway may occur when the autopilot is first engaged, as described in Garmin Service Alert 22109. This service bulletin contains instructions to disable electric pitch trim as an alternate method of compliance with Service Alert 22109.

WARNING
Engagement of the autopilot with this condition may result in an un-commanded deviation from the intended or desired flight path.

ACTION:

Before further flight, one of the following actions must be completed:

Disable the GFC 500 Autopilot by pulling the AUTOPILOT circuit breaker and placard the Autopilot ‘Inoperative.’

OR

Contact a Garmin dealer to disable the pitch trim as directed in Garmin STC SA01866WI Service Bulletin 22110.


RESOLUTION:

This issue will be corrected in a future software update (expected in Q4 of 2022).

https://support.garmin.com/en-US/aviation/faq/s7SeFk9oh96I8qVfjtNbV8?keywordSearch=22109
 
I wonder how many are going to say it's just a Service Bulletin and it's not mandatory because we're experimental aircraft and ignore it? I know the reality of it but some here have made that claim before for other Service Letters. Hopefully they take this one seriously.
 

Chock full of other goodies as well!

Changes made from version 9.01 to 9.12:
• Add optional audio alert for high-airspeed condition
• Add optional audio alert when reaching safe altitude after takeoff
• Add optional audio alert when approaching VNAV profile
• Add optional CAS reminder to check baro setting when on the ground
• Add ability to disable ESP by holding AP DISC button for 5 seconds
• Add ability to configure GPS integrity for GTX xx5R transponders
• Add support for additional RS-232 formats for GTX xx5R transponders
• Add automatic IGRF data update from navigation database
• Improve GSA28 hardware monitoring
• Improve traffic audio alerts
• Improve Smart Glide operation and glide range ring
• Improve transponder behavior when STBY mode is selected before takeoff
• Improve visibility of selected track/heading lines on map
• Improve functionality of GEA 24 backup RS-232 connection
• Improve EIS configuration and calibration
• Improve ESP operation
• Improve flight plan Leg ESA data field
• Improve local time data fields
• Improve chart display
• Improve radio tuning
• Improve data logging
• Improve airspace alerting
• Improve diagnostic pages
• Improve LRU software update process
• Improve MapMX RS-232 interface
• Improve map display of TFR, NOTAM, and obstacle data
• Correct display of winds aloft magnitude for FIS-B sources
• General improvements to system operation
• Includes update to G5 software version 8.16
• Includes update to G5 boot block software version 2.30
• Includes update to GDL5x software version 2.19
• Includes update to GMU11 software version 2.20
• Includes update to GMU11 boot block software version 2.10
• Includes update to GSA28 software version 5.20/2.50
• Includes update to GSU25/B software version 4.40
• Includes update to GSU25/B boot block software version 2.30
• Includes update to GSU25C/D software version 2.90
• Includes update to GSU25C/D boot block software version 2.10
• Includes update to GTR20/200 software version 3.50
• Includes update to GTR20/200 boot block software version 2.40
• Includes update to audio database version 2.80
• Includes update to timezone database version 31.00
• Includes GAD13 software version 2.10
• Includes GAD13 boot block software version 2.00
• Includes GAD27 software version 2.70
• Includes GAD27 boot block software version 2.30
• Includes GAD29 software version 3.40
• Includes GAD29 boot block software version 3.10
• Includes GAD29C/D software version 2.10
• Includes GAD29C/D boot block software version 2.00
• Includes GDL39 software version 4.91
• Includes GEA24 software version 3.90
• Includes GEA24 boot block software version 2.20
• Includes GI260 software version 2.80
• Includes GI260 boot block software version 2.20
• Includes GMA245 audio software version 2.20
• Includes GMA245 Bluetooth software version 2.00
• Includes GMA245 software version 2.80
• Includes GMA245 boot block software version 2.30
• Includes GMC507 software version 3.10
• Includes GMC507 boot block software version 2.30
• Includes GPS20A software version 2.40
• Includes GPS20A boot block software version 2.10
• Includes GSA28 boot block software version 2.20/2.10
• Includes GSU73 software version 3.80
 
EAB Specific Service Bulletin

The issue described in the Experimental counterpart to the GFC 500 Service Alert posted in this thread is explained in more detail in this post.

We have since released GDU 4XX software v9.12 to resolve the issue, more information on that software package can be found here.

Thanks,

Justin
 
Garmin Runaway Trim

I have a new RV14A and this happened the first time we tested the autopilot. It has happened twice since, even after loading version 9.13 yesterday in the G3X which was supposed to fix the problem. Twice the runaway trim engaged immediately when the autopilot was engaged and once the trim ran full down after the plane was in autopilot track mode for 10 minutes working fine. Both up trim and down trim runaway were experienced - all at 8500 AGL.

I've pulled the breaker and don't plan on using the autopilot until its gets fixed and other folks test it a bit. My advice is to be careful until this is sorted out.

Looking for guidance from the folks at Garmin on this issue.
 
I have a new RV14A and this happened the first time we tested the autopilot. It has happened twice since, even after loading version 9.13 yesterday in the G3X which was supposed to fix the problem. Twice the runaway trim engaged immediately when the autopilot was engaged and once the trim ran full down after the plane was in autopilot track mode for 10 minutes working fine. Both up trim and down trim runaway were experienced - all at 8500 AGL.

I've pulled the breaker and don't plan on using the autopilot until its gets fixed and other folks test it a bit. My advice is to be careful until this is sorted out.

Looking for guidance from the folks at Garmin on this issue.

Are you sure your trim is not wired backwards?
 
Trim Motor Direction/ Switch Wiring

I have a new RV14A and this happened the first time we tested the autopilot. It has happened twice since, even after loading version 9.13 yesterday in the G3X which was supposed to fix the problem. Twice the runaway trim engaged immediately when the autopilot was engaged and once the trim ran full down after the plane was in autopilot track mode for 10 minutes working fine. Both up trim and down trim runaway were experienced - all at 8500 AGL.

I've pulled the breaker and don't plan on using the autopilot until its gets fixed and other folks test it a bit. My advice is to be careful until this is sorted out.

Looking for guidance from the folks at Garmin on this issue.

Hey Jim,

This sounds like an installation issue, can you please send us a log of one of your flights to [email protected]? We can surely help figure out what is causing the problem.

We provide comprehensive on ground testing to ensure everything is working as it should on the ground, prior to ever using the autopilot in flight. Did you verify trim direction using the tests outlined in 35.4.10.5 Step by Step On-Ground Setup of the Installation manual?

Thanks,

Justin
 
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