As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN)DURING SPAR REPLACEMENT ON THE WING, ALL BOLTS WERE FOUND TO BE CORRODING WHERE THEY CONTACT THE WOOD. THE HEAD AND THREAD OF THE BOLTS WAS FOUND TO BE CLEAN AND BRIGHT BUT THE SHANK OF THE BOLT IN TH E WOOD SHOWS SERIOUS CORROSION.