Story ID: 
Garmin Resolves GFC 500 Runaway Trim Issue
By: Matt Thurber
Caption: Pending the latest fix, owners of aircraft affected by the potential Garmin GFC 500 runaway trim issue had to disable elevator pitch trim systems.
Word Count: 194
The FAA has approved Garmin’s software update and service bulletin to fix the “potential runaway pitch trim issue” that has affected some GFC 500 autopilots. The situation applies to aircraft that are equipped with the GFC 500 and optional pitch trim.
Garmin explained that the software update for the GFC 500 with G5 instruments and G3X Touch displays “allows pitch trim to be enabled as a closing action to Service Alert 22109 and STC Service Bulletin 22110." The Olathe, Kansas, avionics manufacturer expects to release software to cover GI 275 instrument installations “in the coming weeks.”
A Garmin aviation service document notification tells owners that the software update must be accomplished in the next six months or at the next service interval, whichever comes first. The warranty reimbursable period ends on June 30, 2023.
According to Garmin, affected units include “GFC 500 autopilot systems with an optional GSA 28 pitch trim installed using STC SA01866WI, master drawing list 005-01264-00, Revisions 1 through 76.” Validation of the software update from European, UK, and Brazilian aviation regulators is underway, the company said.