Updated Jan. 13, 2023

Garmin recently issued an update regarding its software update necessary to address a potential runaway pitch trim issue. From Garmin.

Garmin has received FAA approval for the updated software and service bulletin addressing the potential runaway pitch trim issue of the GFC 500 autopilots on aircraft with optional pitch trim installed. The updated GFC 500 software for G5 and G3X Touch installations allows pitch trim to be enabled as a closing action to Service Alert 22109 and STC Service Bulletin 22110.

The Aviation Service Document Notification describes the software update procedures for impacted owners and operators. Updated software for installations using the GI 275 is expected to be available in the coming weeks. Additionally, the team is working to validate the FAA software installation approval with European, UK, and Brazilian aviation regulatory agencies. We will continue to issue updates as more information becomes available. 

A Garmin representative also told the Piper Owner Society:

For Certified aircraft, the following software has been published with a Service Bulletin with instructions for Garmin dealers to perform the update. Installs with a G5 or G3X Touch should schedule this with their Garmin dealer.

  • G3X Touch v9.02
  • G5 v8.02

Editorial Board member and Garmin owner Scott Sellers said his suggestion is to “contact your Garmin dealer to schedule a time to install the software update,” but he added that it would be premature for another week or two. He said the software was available to dealers on Friday, January 13, but his dealer suggested it wouldn’t be scheduled for install until later in January.


Garmin has announced service alerts 21109 and 22110 for the GFC 500 Autopilot to warn users that “an un-commanded automatic pitch trim runaway may occur when the autopilot is first engaged.”

Service Alert 21109 explains how users can disable the autopilot themselves by pulling the circuit breaker. Service Alert 22110 explains that users can contact a Garmin dealer to follow a Garmin STC to disable electric pitch trim as an alternate method of compliance.

Aircraft Affected

The alerts apply to “all certified Garmin GFC 500 Autopilots with an optional GSA 28 pitch trim servo including those installed by STC SA01866WI. GFC Autopilots installed in Cirrus SR20/22 aircraft using STC SA01866WI are not affected. For Experimental and Light Sport installations, refer to Garmin Service Bulletin 22112.”

Action to Be Taken

Service Alert 21109 states the following:

“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.’


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


According to the two service alerts, the problem “will be corrected in a future software update (expected in Q4 of 2022).”


For Service Alert 22109, visit the Garmin website here:


Download the PDF here:


For Service Alert 22110, visit the Garmin website here:


Download the PDF here:


Read more reaction and discuss this in the forum here.