As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING A NR 1 ENGINE INLET AND FAN BLADES DETAILED INSPECTION, FOUND 12 NUTPLATES ON AFT OTBD FAN CASE THAT APPEAR TO HAVE CORROSION UNDER & AROUND ON FAN CASE. THE NUTPLATES ARE FOR AFT ACOUSTICAL PANELS BETWEEN THE 1 O'CLOCK TO 10 O'CLOCK POSITIONS. ACFT GROUNDED. REMOVED & REPLACED THE NR 1 ENGINE IAW TASK CARDS 78471000, 78471001. COMPLETED GROUND RUN DUCT PURGE IAW EA PWRPL-71, AND EA-11276.