What was found
REMOVED LT & RT INBD FLAP EXTEND CABLES FROM BOTH INBD FLAP BELLCRANKS TO INSPECT FOR WEAR OR DAMAGEDURING 100HR, ANNUAL INSPECTON PROCESS. FOUND APPROX 1" BEHIND CABLE END THREADED FITTINGS BOTH CABLES HAD SIGNIFICANT BROKEN WIRE STRANDS WHICH UNDETECTED, WOULD HAVE LEAD TO EVENTUAL FAILURE. CABLES ARE STEEL TYPE WITH 3795.4 HRS (ORGINIAL CABLES SINCE NEW). ALL FLAP CABLES REPLACED WITH NEW & FLAP SYSTEM RIGGED PER SERVICE MANUAL. SUGGEST THESE CABLES BE REMOVED AND INSPECTED ON 500HR MIN BASIS AS THIS IS BECOMING AN ISSUE ON THIS TYPE ACFT, FLEET WIDE. THESE CABLES MUST BE REMOVED FROM THE BELLCRANK FOR PROPER INSPECTION. THESE CABLES LOOKED FINE WHEN INSTALLED BUT WERE OBVIOUSLY NOT AIRWORTHY.