Readers who use mobile radar apps or often find themselves around the airport perimeter fence will know that hub-and-spoke airlines, meaning airlines that operate most of their flights between one central airport, will know they operate with two sub-fleets. These are narrowbodies and widebodies. Many of the world's flag carriers follow this model. Qatar Airways, the flag carrier of Qatar, is one of the most famous examples. Today, we will examine both them and Air France as case studies.