The research reported here explores the interdependencies between the operation and organisation of the world’s airline industry and the air services available at cities. Previous research on this issue focussed attention on passenger numbers to produce hierarchies of airports and traffic networks between them. The current paper adds to that knowledge by providing insight on measures such as the airlines and aircraft used to service cities at different levels in a hierarchy. Its core idea is that the arrangement of air services at cities reflects airlines’ operations, seen via their size, the type of aircraft used and their mode of operation. The research uses a commercial data base that records a range of measures of air services. It applies that data to an established classification of cities to show the difference in the characteristics of services at three categories in the city classification. Results show differences in aircraft, airline size and mode of operation are apparent from one category of city to another. The results have implications for policy on the airline industry and airport management. As the approach is limited to a single year, and reports upon aggregate global results, there is considerable research potential in widening the analysis to include regions of the world, and also to explore changes over time.