As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING C-13 CHECK 6 EACH CRACKS WERE FOUND BETWEEN FASTENERS ON NR 4 LEADING EDGE SLAT LOWER SKIN AT SLAT ACTUATOR. MAINTENANCE CUT OUT CRACKED AREA OF LOWER SLAT SKIN; PERFORMED HFEC INSPECTION TO VERIFY NO CRACKS EXIST; FABRICATED A FILLER AND REPAIR SPLICE; INSTALLED REPAIR PARTS IAW B737-300 SRM 57-43-01 PG 216-219.