On Oct. 10, the FAA released a Notice of Proposed Rulemaking (NPRM) that affects the Garmin GFC 500 Autopilot System. The proposed AD would affect a number of aircraft models, including Cessna 172, 177, 182, 206, and 210, as well as Piper PA-24. PA-28, and PA-32. It would require operators to update their software within 12 months of the effective date of the AD, unless it has already been done. The NPRM was issued because of a report of a F33A Bonanza experiencing “an uncommanded automatic pitch trim runaway when the autopllot was first engaged.”
According to the NPRM, “The FAA proposes to adopt a new airworthiness directive (AD) for various airplanes modified with a certain configuration of the Garmin GFC 500 Autopilot System installed per Supplemental Type Certificate (STC) No. SA01866WI. This proposed AD was prompted by a report of an uncommanded automatic pitch trim runaway when the autopilot was first engaged. This proposed AD would require updating the applicable Garmin GFC 500 Autopilot System software for your airplane and would prohibit installing earlier versions of that software. The FAA is proposing this AD to address the unsafe condition on these products. The FAA must receive comments on this proposed AD by November 24, 2023.”
The FAA estimates the cost of the software upgrade to be $85.