As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HEAVY CHECK, LT WING RIB 10 EXTENSION IS CRACKED ORIGINATING AFT SIDE OF FASTENER HOLE THAT IS THE THIRD HI LOC FROM AFT SIDE OF THE RIB TOP SIDE OF RIB. MAINTENANCE INSTALLED SERVICABLE RIB 10 EXTENSION IAW SRM 51-40-00, 51-21-00.