Have a look over at Avcanada.ca and you may get a better idea of whats going on at Air Canada. The ACPPA cost (and continues to cost) millions of dollars due to restrictions that no other airlines in Canada are subject to.
All the cost cutting measures mentioned earlier in this thread were done last time we were in CCAA. Unfortunately those in management were only interested in dismantling the airline and selling off the parts to make a massive amount of money for the shareholders. There has been over 2 BILLION dollars taken out and given away. Management has earned millions of dollars while the company slid downhill and now they're crying poverty...