As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE LT & RT CENTER WING FUEL CELL ACCESS HAD CORROSION ON THE FLANGE. THIS IS THE SECOND B300 THE REPAIR STATION HAS SEEN WITH THIS PROBLEM. THE FLANGE IS HIDDEN BY THE FUEL CELL ACCESS PANEL AND IS NOT READILY VISIBLE DURING NORMAL MAINTENANCE. THE KING AIR SERIES HAS A HISTORY OF WATER INGRESS IN THIS AREA, HOWEVER THE B300'S ARE SHOWING CORROSION ON THE WING SKIN FLANGES. ONE COVER PLATE WAS REPLACED, BOTH WING SKIN FLANGES WERE REPAIRED PER THE KA SIRM.