Air Canada B763 near Montreal on Dec 15th 2013, cabin pressure problems

An Air Canada Boeing 767-300, registration C-GHOZ performing flight AC-832 from Montreal,QC (Canada) to Brussels (Belgium), was enroute at FL290 about 190nm northeast of Montreal when the crew declared emergency reporting cabin pressure problems and decided to return to Montreal. The aircraft followed a normal descent profile to FL200 and further down for a safe landing on Montreal's runway 24R about 100 minutes after turning around and leaving FL290.