Developing a major new aircraft type is always risky. For Bombardier, however, the CSeries carries more than a whiff of a high-stakes roll of the dice.
Simply, its CRJ range is losing ground in the regional jets market, so it may take CSeries success to keep Bombardier in the large aircraft business. But the project's huge ambition raises the stakes even higher.
The cost is massive - out of a $2.6 billion budget Bombardier is directly taking on $1 billion, which is huge compared with its aerospace turnover of $10 billion.
Then, the CSeries is not another regional jet. It's a small airliner that competes squarely with the smaller Airbus A320 and Boeing 737 models.
Is Bombardier mad? The narrowbody market is served nicely by the A320 and 737, and their replacements will enjoy budgets that dwarf Bombardier's to promise genuine next-generation narrowbodies with fuel economy gains far beyond what's offered by CSeries and its Pratt & Whitney GTF geared turbofan engine.
Except it may turn out that new technology will not in practical reality let even the big two airframers significantly better the CSeries for the foreseeable future, and for urgent fleet upgrades the choice will soon be between tomorrow's CSeries and today's 737s or A320s.
The CSeries could yet break Bombardier. But it just might propel it into the big three.