As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
INSPECTION TYPE: C, LT WING - NR 4 VC FLAP O/B ROTARY ACTUATOR SUPPORT RIB MOUNT BOLT HOLES BORE AREA FOUND CORROSION AT HOLE NR 1, 2, 4, 5, 7 & 8 ( VIEW FROM I/B ). BOLT HOLES CORROSION REMOVED AND INTERIM REPAIRED AS PER RS 57-41-35014 AND UPS EO B747-5740-18687-A.