As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE PERFORMING MAINTENANCE ON AIRCRAFT, IT WAS DISCOVERED THAT APPROXIMATELY 10 NUTS ON EACH WING THAT SECURES UPPER WING PLANK TO REAR SPAR UPPER FLANGE, FROM REAR SPAR STATION 161.1 TO 281.8 WERE CRACKED, WITH SOME MISSING PARTS OF THE NUT. AS A PRECAUTION, A TOTAL OF 96 SCREWS AND NUTS AT THESE LOCATIONS WERE REPLACED WITH NEW HARDWARE.