“…The first is about the features of the air transportation network and its spatial organization mechanism, including the elastic evaluation of the air transportation network ( 5 ), network structure ( 6 ), complexity of networks ( 7 , 8 ) and robustness analysis ( 9 ), air transportation radiation network ( 10 ), multiple networks ( 11 ), convergent networks ( 12 ), characteristic analysis and simulation ( 8 ), air transportation network complexity ( 13 ), centrality and community ( 14 , 15 ), nodality ( 16 ), scalability ( 17 ), air connectivity index ( 18 ), fractal characteristics ( 19 ), the aerodynamics of an air transportation network ( 20 ), and its spatial and temporal evolution ( 21 ). The second is about the geographical distribution of aviation flows, including hub airport system ( 22 ), spatial concentration ( 23 , 24 ), the geographical pattern of air passenger and freight flows in different countries and regions ( 25 ), the impact of special events ( 26 ), and spatial strategy of low-cost aviation network ( 27 ). The third is to study urban networks based on aviation flows, including regional urban connection intensity ( 28 ) and international urban systems based on the spatial distribution of air passenger and freight flows and their driving factors ( 29 ).…”