As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
PAX DOOR SURROUND BACK-UP SILL AT STR 21L, BETWEEN FS310 AND FS319 HAS CORROSION. (C-CHECK) RO 6/24/2020 REPLACED PAX DOOR BACK-UP SILL PER SRM, DRAWING SH670-31810 REV Y, DRAWING. SEE CONTINUATION CARD FOR DETAILS. COMPLIED WITH TASK CARD AND FORM M-337.