An A320 ECAM alerted right window heat inoperative accompanied by a large single crack which minutes...

Narrative:

During cruise ECAM: right window heat inoperative. 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.

Original NASA ASRS Text

Title: 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.

Narrative: 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.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

Attributes
ACN	1015111
Time
Date	201206
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.ARTCC
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	A320
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Cockpit Window
Person 1
Function	Captain Pilot Flying
Qualification	Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Critical Inflight Event / Encounter Weather / Turbulence Inflight Event / Encounter Fuel Issue

An A320 ECAM alerted right window heat inoperative 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.