As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING THE MAINTENANCE BASE VISIT FOUND FRAME 23 BETWEEN STRINGER 15 RIGHT AND 16 RIGHT TO BE CRACKED AROUND RIVET WHERE AFT SERVICE DOOR SILL IS ATTACHED. THE AIRCRAFT WAS REMOVED FROM SERVICE. COMPLIED WITH INSTALLATION OF FRAME SECTION IAW SRM 51-40-02 AND EO EM 53MR-1608. THE AIRCRAFT WAS RETURNED TO SERVICE.