What was found
FOUND #4 SPEED BRAKE BOTH HYDRAULIC PRESSURE AND RETURN CARRY THRU'S HAVE CORROSION AROUND THEM ON LH WING AFT SPAR. MECHANICALLY REMOVED CORROSION LOCATED WHERE #4 SPEED BRAKE HYD PRESSURE AND RETURN LINE CARRY THRU FITTINGS ARE LOCATED ON LH WING AFT SPAR, AFT FACE INSIDE FLAP COVE IAW CESSNA 680 SRM 51-70-02. FOUND CORROSION BLENDS TO BE BEYOND LIMITS IAW CESSNA 680 SRM 51-70-02 EXCEEDING .002" OF MATERIAL REMOVED FROM NOMINAL THICKNESS. REPAIRED CORROSION BLENDS IAW NETJETS AQRD RFTS-116439 REV.0,