As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LT WING - NR 4 VC FLAP I/B ROTARY ACTUATOR SUPPORT RIB MOUNT BOLT HOLES BORE AREA FOUND CORROSION AT HOLE NR 1, 3, 4, 6 & 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.