As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHILE CLEANING LITE CORROSION ON SURFACE OF BELLY AFT OF WINGS, NOTICED SOME APPARENT BLISTERING OF THE SKIN. INVESTIGATION REVEALED THERE WAS CORROSION BETWEEN THE SKIN AND THE FUSELAGE FRAME. AFFECTED SKIN WAS CUT OUT AND REPLACED AS A COVER PATCH IN ACCORDANCE WITH BEECH STRUCTURAL REPAIR MANUAL.