The aircraft industry is one of the clearest case studies of how capital intensity, long development cycles, and political pressure create near-unbreakable duopolies.

Bombardier spent around $7–8B developing the CSeries, but a steep discount to Delta triggered a 300% U.S. tariff, killing the program. Airbus later acquired it for $1.

I wrote a breakdown of what went wrong; engineering missteps, cost overruns, government intervention, and why COMAC may be the only realistic future challenger.