Airbus and Boeing manufacture planes after they receive an order
Significant government subsidies
Airbus and Boeing have received significant subsidies from EU and US governments respectively.
The subsidies have been so much that the World Trade Organization (WTO) had to investigate these subsidies to make sure that it wasn’t in contravention of international trade practices.
Why can’t a new player break in
It is hard for a new company to break this duopoly because
You can’t get a presale if you don’t have a proven jet