As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING THE PERFORMANCE OF THE DOC 15 INSPECTION, IT WAS NOTICED THAT THERE WAS LEVEL II AND LEVEL III COROSSION ALONG THE AFT VERTICAL SPAR OF THE VERTICAL STABILIZER UNDER THE TRAILING EDGE SKIN PANEL ABOUT HALFWAY DOWN FROM THE TOP OF THE SPAR. THE RUDDER WAS REMOVED AND THE AREA CLEANED UP AND IT WAS NDTIAW NDT REPORT # D11566. TEXTRON DETERMINED THAT THE SPAR CAP HAD TO BE REPLACED.