jammerh - CSeries Orders Not "Critical" - MNZTR Hi MNZTR, sorry for the tardy response. As before, you make some interesting points. Yes, I realize there are differences of course. But then there are similarities between the two which make them similar if only by virtue of being newer, more modern commercial jet aircraft.
As for referring to CSeries as an RJ, it's Bombardier iteself which refers to CSeries as a regional jet. Both aircraft use a much higher percentage of carbon composite materials to help lighten the load. Together with new power plants (each from different manufacturers - actually Boeing rejected the GTF for the 787) these lighter materials and aerodynamic changes make each aircraft significantly more fuel efficient, and operationally efficient.
As for how many, Bombardier itself has estimated it could take as many as half of the estimated demand of about 5000 units.