Airbus has released the results of a study that documents which air routes to African cities are underserved (extracts from the report below).
Factors at play are constraints on the number of flights due to bilateral agreements that are in place, challenges with capacity at airports, and economic variables such as the profitability of these routes.
Just in general, Airbus reports that the expectation is for air travel worldwide to increase by about 4.1% over the next 20 years, which would mean some 1,180 new aircraft need to be built, and 15,000 additional pilots would be needed.