What was found
REPORTED AT FL350, RT WINDSHIELD CRACKED & HEARD ARCING IN WINDSHIELD. RETURNED & LANDED WITHOUT FURTHER EVENT. MX R & R RT WINDOW IAW AIRBUS 320 MM 56-11-11 AND REPLACED RT WINDOW HEAT CONTROLLER IAW AIRBUS 320 MM 30-42-30. OPS & LEAK CHECKS GOOD. ROOT CAUSE OF FAILURE OF WINDOW WAS ATTRIBUTED TO MOISTURE INGRESS. WINDOW WAS SCRAPPED AT VENDOR. VENDOR FOUND NO FAULT WITH THE WINDOW HEAT CONTROLLER. OPERATIONAL CHECKS WERE GOOD. VENDOR PERFORMED FULL FUNCTIONAL TESTS AND INSPECTED WINDOW HEAT CONTROLLER IAW SAGEM CMM 30-42-36 REV. ORIG.