As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WINGLET, 0012L, LEFT WING ATTACH HARDWARE. WINGLET WAS BEING REPLACED BECAUSE OF DAMAGE AND THE ATTACH HARDWARE WAS SEVERELY CORRODED. SUSPECT WATER INTRUSION INTO SEALED AREA. INSTALLED NEW WINGLET AND SEALED IAW MFG PROCEDURES. PARTS REPLACED: BOLT P/N NAS 1165-51L, -65L. SLEEVES P/N 1159WM30707-11, AND -15.