What was found
FLIGHT 3217 - DCA-SDF - IN CRUISE AT FL320, HEATING ELEMENT IN CAPTAIN’S FRONT WINDSHIELD BEGAN ARCING. IMMEDIATELY TURNED OFF CAPTAIN’S WINDSHIELD HEAT. THE ARCING CEASED ONE THE HEAT WAS TURNED OFF. APPROXIMATELY 15 SECONDS LATER, A BRIGHTER ARC "POPPED" AGAIN AND THE WINDSHIELD CRACKED IN A SPIDER WEB PATTERN. BEGAN AN IMMEDIATE DESCENT AND DECLARED AN EMERGENCY. THE CABIN MAINTAINED NORMAL PRESSURE THROUGH OUT THE REMAINDER OF THE FLIGHT AND LANDED NORMALLY. MAINTENANCE REMOVED AND REPLACED THE CAPTAIN’S SIDE WINDSHIELD.