As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING M-CHECK FOUND L4 DOOR LOWER SILL WEB CORRODED AT STA 1640. REMOVED L-4 DOOR SILL WEB AND 5 (EACH) STIFFENERS IAW SRM 51-40-02. FABRICATED NEW L-4 DOOR SILL WEB IAW SRM 51-40-05. TREATED, PRIMED, AND APPLIED TOPCOAT IAW SRM 51-20-01 AND AMM 51-21-10. INSTALLED DOOR SILL WEB AND 5 EA STIFFENERS IAW SRM 51-40-02.