As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CORROSION AND THREAD DAMAGE WERE FOUND COMMON TO FORWARD BOLT HOLE LOCATIONS (4 EA INBOARD AND OUTBOARD SIDES) OF NR 4 TRAILING EDGE FLAP TRACK. THREAD DAMAGE WAS COMMON TO THE FAIL-SAFE BAR OUTBOARD HOLE NR 3. THE CORROSION AND THREAD DAMAGE WERE REMOVED AND THE BOLT HOLES WERE REWORKED PER BOEING SERVICE BULLETIN 747-57-2256 AND EIA ECRA 470-57-125-2.