What was found
DURING 600HR INSPECTION AFTER REMOVAL OF HORIZONTAL STABILIZER FOR DETAILED INSPECTION. OBSERVED WHAT WAS THOUGHT TO BE A SPOT OF CORROSION ON LOWER LH STABILIZER SKIN, WHICH UNDER CLOSE INSPECTION WAS DETERMINED TO BE A 4 MM HOLE IN SKIN. LOCATION IS 4 INCHES INBOARD OF OUTER RIB AND 2 INCHES AFT OF SPAR. UPON REMOVAL OF END RIB FOR INSPECTION FOUND HOLE WAS CAUSED BY CHAFING FROM A HARD PLASTIC MOLEX TYPE CONNECTOR FOR THE NAV LIGHT. PERFORMED SHEET METAL REPAIR FROM OEM REPAIR DESIGN APPROVAL SHEET. THE LOOSE CONNECTOR WAS SECURED INTERNALLY TO ALLEVIATE FUTURE CHAFING.