Airframe Log Entry. 1. Removed Garmin GPS GNS430 S/N 97129149 for screen replacement with a temporary Garmin GPS GNS430 S/N 23421977. Sent unit to MAC Avionics for repairs or to be sent to Garmin for repair or updating. All maintenance performed on this Aircraft was conducted in reference with Cessna 172 Service Manuals as revised and the current regulations of the Federal Aviation Administration and is approved for return to service with respect to the work performed.