AD FAA-2007-28730

The FAA adopts a new airworthiness directive (AD) for certain GARMIN International (GARMIN) GSM 85 servo gearbox units that are installed on airplanes. This AD requires you to inspect the GSM 85 servo gearbox for foreign object debris and return the unit to the manufacturer for replacement if you find debris. This AD results from reports of certain GARMIN GSM 85 servo gearbox units that have foreign object debris inside the assembly. We are issuing this AD to detect and correct defective GARMIN GSM 85 servo gearbox units, which could result in jamming of the gearbox. Jamming of the gearbox could lead to the pilot having to apply sufficient control force to override the servo gearbox slip clutch in order to control the airplane. In certain situations, this could compromise the safety of the airplane if the pilot was not able to focus on critical duties due to having to tend to the servo gearbox.