There are plenty of opportunities for new models; Boeing wanted to make 3 new aircraft, and had to settle for 1 new and 2 upgrades. The 737 has been flying for

There are plenty of opportunities for new models; Boeing wanted to make 3 new aircraft, and had to settle for 1 new and 2 upgrades. The 737 has been flying for almost 50 years, and Boeing still can't give it long enough landing gear to properly accommodate properly-sized turbofans because of the regulatory burdens. Bombardier thought there was an opportunity for a new single-aisle airliner, but hasn't been able to come up with the money to get a certificate. The fact that there are no new aircraft manufacturers coming on-line only proves that the regulators have created a duopoly.