What was found
APPROXIMATELY ONE HOUR AFTER DEPARTURE, FLIGHT EXPERIENCED PROBLEM WITH RIGHT FORWARD WINDOW ARCING AND CRACKED. FLIGHT RETURNED TO ORD LANDING OVERWEIGHT. PRELIMINARY FINDINGS INDICATES DELAMINATION OF THE ANTI FOG LAYER CAUSING ARCING FROM THE BUS BAR, AND RESULTING IN CRACKING. WINDOW P/N 141W7400-2 WAS REPLACED AND THE AIRPLANE WAS RETURNED TO SERVICE. SUSPECT FAILURE WAS CAUSED FROM WORKMANSHIP.