As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING OP 16 MAINT CHECK FOUND CRACK IN UPPER END OF VERTICAL STIFFENER AT STA 1019, APU ENCLOSURE LEFT SIDE. REMOVED STIFFENER AND SENT TO WELDING SHOP. STIFFENER WAS WELDED PER INTER-SHOP TICKET 799450. REPLACED STIFFENER WITH HI-LOKS HLT336 PER SRM 51-30-5.