As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FAT - AIRCRAFT DIRECTIONAL HEADING REPORTED OFF DURING CRUISE FLIGHT. AIRCRAFT RETURNED TO STATION WITHOUT INCIDENT. AVIONICS INSPECTED AND TESTED COMPASS SYSTEM AND NAVIGATION SYSTEM. NO DEFECTS NOTED. UNABLE TO DUPLICATE REPORTED DISCREPANCY. AIRCRAFT RETURNED TO SERVICE. (M)