A320
Flight Crew Air Transport Pilot (ATP)
Workload; Situational Awareness; Fatigue; Distraction; Time Pressure
Aircraft Equipment Problem Critical; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Fuel Issue
Flight Crew Diverted; Flight Crew FLC complied w / Automation / Advisory; General Maintenance Action; General Flight Cancelled / Delayed
Aircraft; Company Policy
During cruise ECAM: R WINDOW HEAT INOP.  Window heat controller malfunctioned developing large single crack in outer layer of pane.  Completed ECAM actions.  Approximately 2 minutes later right window cracked completely.  Followed non-ECAM abnormal procedure (windshield crack).  Conferred with Dispatch and the decision was made to divert to a nearby airport due to enroute forecast icing conditions.  Descended to lower altitude to reduce landing weight; but encountered turbulence.  Completed windshield crack procedure prior to landing and followed overweight landing procedures as a precaution (FMGC predicted the landing weight within limits; but may have been inaccurate due to SID).  Complied with international divert procedures upon arrival at gate.  Repositioned aircraft to domestic gate after clearing customs.  Determined crew needed to enter rest after confirming with Maintenance Control that no immediate fix was possible and Dispatch had no options for replacement aircraft.  Calculated supplemental rest requirements and coordinated with crew planning for hotel assignment. I would suggest more accurate FMGC fuel prediction would aid crews in determining forecast landing weight quickly to avoid the potential for landing overweight.
An A320 ECAM alerted R WINDOW HEAT INOP accompanied by a large single crack which minutes later developed into a completely cracked window; so the flight diverted to a nearby airport to avoid enroute weather.